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Sample records for streptozotocin-induced beta-cell damage

  1. Protective Effect of Royal Jelly against Renal Damage in Streptozotocin Induced Diabetic Rats

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    Elham Ghanbari

    2015-03-01

    Full Text Available Background: Royal jelly has been shown to have antioxidant and antidiabetic effects. The objective of this study was to evaluate the protective effect of RJ against kidney damage in streptozotocin induced diabetic rats. Methods: Thirty two male Wistar rats were divided randomly into four groups (n=8 per group. Normal control and diabetic control groups received 1cc/day distilled water, normal RJ-treated and diabetic RJ-treated groups received 100mg RJ/kg body weight daily. Diabetes was induced by intraperitoneal injection of streptozotocin. At the end of the experiment, urine and kidney samples were collected for biochemical and histopathological analysis. Results: The results showed that diabetes could increase levels of urine urea, total protein and albumin significantly, and could decrease the levels of creatinine and uric acid in urine. In the kidney tissue homogenates, catalase activity and antioxidant power were significantly lower, whereas malondialdehyde levels were significantly higher in diabetic group when compared with control group. Diabetic rats showed severe histological changes in kidney tissues. Treatment of diabetic rats with RJ improved significantly all of these parameters. Conclusion: The present study revealed that treatment with RJ resulted in significant improvement in histopathological alterations in kidney tissue and urine parameters of diabetic rats. This could be due to its antioxidant activity and the ability of RJ for scavenging the free radicals released in diabetes. These findings suggest that RJ has protective effects on kidneys affected by diabetes mellitus.

  2. Adipose Tissue-Derived Mesenchymal Stem Cells Exert In Vitro Immunomodulatory and Beta Cell Protective Functions in Streptozotocin-Induced Diabetic Mice Model

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    Hossein Rahavi

    2015-01-01

    Full Text Available Regenerative and immunomodulatory properties of mesenchymal stem cells (MSCs might be applied for type 1 diabetes mellitus (T1DM treatment. Thus, we proposed in vitro assessment of adipose tissue-derived MSCs (AT-MSCs immunomodulation on autoimmune response along with beta cell protection in streptozotocin- (STZ- induced diabetic C57BL/6 mice model. MSCs were extracted from abdominal adipose tissue of normal mice and cultured to proliferate. Diabetic mice were prepared by administration of multiple low-doses of streptozotocin. Pancreatic islets were isolated from normal mice and splenocytes prepared from normal and diabetic mice. Proliferation, cytokine production, and insulin secretion assays were performed in coculture experiments. AT-MSCs inhibited splenocytes proliferative response to specific (islet lysate and nonspecific (PHA triggers in a dose-dependent manner (P<0.05. Decreased production of proinflammatory cytokines, such as IFN-γ, IL-2, and IL-17, and increased secretion of regulatory cytokines such as TGF-β, IL-4, IL-10, and IL-13 by stimulated splenocytes were also shown in response to islet lysate or PHA stimulants (P<0.05. Finally, we demonstrated that AT-MSCs could effectively sustain viability as well as insulin secretion potential of pancreatic islets in the presence of reactive splenocytes (P<0.05. In conclusion, it seems that MSCs may provide a new horizon for T1DM cell therapy and islet transplantation in the future.

  3. Edaravone Protect against Retinal Damage in Streptozotocin-Induced Diabetic Mice

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    Liu, Xiaoyi; Chen, Xi; Xie, Ping; Yuan, Songtao; Zhang, Weiwei; Lin, Xiaojun; Liu, Qinghuai

    2014-01-01

    Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), a free radical scavenger, is used for the clinical treatment of retinal injury. In this study, we investigated the protective effects of edaravone against diabetic retinal damage in the mouse. Diabetic retinopathy in the mouse was induced by injection of streptozotocin. Edaravone was given once-daily and was intraperitoneally (i.p.) treated at a dose of 3 mg/kg from streptozotocin injection to 4 weeks after onset of diabetes. Retinal ganglion cells (RGCs) damage was evaluated by recording the pattern electroretinogram (ERG). RGCs damage was also detected by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and the levels of reactive oxygen species (ROS) were determined fluorometrically. The expressions of phosporylated-ERK1/2, BDNF, and caspase-3 were determined by Western blot analysis. Retinal levels of ROS, phosphorylated ERK1/2, and cleaved caspase-3 were significantly increased, whereas the expression of BDNF was significantly decreased in the retinas of diabetic mice, compared to nondiabetic mice. Administration of edaravone significantly attenuated diabetes induced RGCs death, upregulation of ROS, ERK1/2 phosphorylation, and cleaved caspase-3 and downregulation of BDNF. These findings suggest that oxidative stress plays a pivotal role in diabetic retinal damage and that systemic administration of edaravone may slow the progression of retinal neuropathy induced by diabetes. PMID:24897298

  4. Edaravone protect against retinal damage in streptozotocin-induced diabetic mice.

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    Dongqing Yuan

    Full Text Available Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one, a free radical scavenger, is used for the clinical treatment of retinal injury. In this study, we investigated the protective effects of edaravone against diabetic retinal damage in the mouse. Diabetic retinopathy in the mouse was induced by injection of streptozotocin. Edaravone was given once-daily and was intraperitoneally (i.p. treated at a dose of 3 mg/kg from streptozotocin injection to 4 weeks after onset of diabetes. Retinal ganglion cells (RGCs damage was evaluated by recording the pattern electroretinogram (ERG. RGCs damage was also detected by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL staining, and the levels of reactive oxygen species (ROS were determined fluorometrically. The expressions of phosporylated-ERK1/2, BDNF, and caspase-3 were determined by Western blot analysis. Retinal levels of ROS, phosphorylated ERK1/2, and cleaved caspase-3 were significantly increased, whereas the expression of BDNF was significantly decreased in the retinas of diabetic mice, compared to nondiabetic mice. Administration of edaravone significantly attenuated diabetes induced RGCs death, upregulation of ROS, ERK1/2 phosphorylation, and cleaved caspase-3 and downregulation of BDNF. These findings suggest that oxidative stress plays a pivotal role in diabetic retinal damage and that systemic administration of edaravone may slow the progression of retinal neuropathy induced by diabetes.

  5. Oxidative Damage to the Salivary Glands of Rats with Streptozotocin-Induced Diabetes-Temporal Study: Oxidative Stress and Diabetic Salivary Glands

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    Kna?, M.; Maciejczyk, M.; Daniszewska, I.; Klimiuk, A.; Matczuk, J.; Ko?odziej, U.; Waszkiel, D.; ?adny, J. R.; ?endzian-Piotrowska, M.; Zalewska, A.

    2016-01-01

    Objective. This study evaluated oxidative damage caused to the salivary glands in streptozotocin-induced diabetes (DM). Materials and Methods. Rats were divided into 4 groups: groups 1 and 2, control rats, and groups 3 and 4, DM rats. 8-Hydroxy-2′-deoxyguanosine (8-OHdG), protein carbonyl (PC), 4-hydroxynonenal protein adduct (4-HNE), oxidized and/or MDA-modified LDL-cholesterol (oxy-LDL/MDA), 8-isoprostanes (8-isoP), and oxidative stress index (OSI) were measured at 7 (groups 1 and 3) and 14...

  6. Oxidative Damage to the Salivary Glands of Rats with Streptozotocin-Induced Diabetes-Temporal Study: Oxidative Stress and Diabetic Salivary Glands.

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    Knaś, M; Maciejczyk, M; Daniszewska, I; Klimiuk, A; Matczuk, J; Kołodziej, U; Waszkiel, D; Ładny, J R; Żendzian-Piotrowska, M; Zalewska, A

    2016-01-01

    Objective. This study evaluated oxidative damage caused to the salivary glands in streptozotocin-induced diabetes (DM). Materials and Methods. Rats were divided into 4 groups: groups 1 and 2, control rats, and groups 3 and 4, DM rats. 8-Hydroxy-2'-deoxyguanosine (8-OHdG), protein carbonyl (PC), 4-hydroxynonenal protein adduct (4-HNE), oxidized and/or MDA-modified LDL-cholesterol (oxy-LDL/MDA), 8-isoprostanes (8-isoP), and oxidative stress index (OSI) were measured at 7 (groups 1 and 3) and 14 (groups 2 and 4) days of experiment. Results. The unstimulated salivary flow in DM rats was reduced in the 2nd week, while the stimulated flow was decreased throughout the duration of the experiment versus control. OSI was elevated in both diabetic glands in the 1st and 2nd week, whereas 8-isoP and 8-OHdG were higher only in the parotid gland in the second week. PC and 4-HNE were increased in the 1st and 2nd week, whereas oxy-LDL/MDA was increased in the 2nd week in the diabetic parotid glands. Conclusions. Diabetes induces oxidative damage of the salivary glands, which seems to be caused by processes taking place in the salivary glands, independently of general oxidative stress. The parotid glands are more vulnerable to oxidative damage in these conditions.

  7. Oxidative Damage to the Salivary Glands of Rats with Streptozotocin-Induced Diabetes-Temporal Study: Oxidative Stress and Diabetic Salivary Glands

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    M. Knaś

    2016-01-01

    Full Text Available Objective. This study evaluated oxidative damage caused to the salivary glands in streptozotocin-induced diabetes (DM. Materials and Methods. Rats were divided into 4 groups: groups 1 and 2, control rats, and groups 3 and 4, DM rats. 8-Hydroxy-2′-deoxyguanosine (8-OHdG, protein carbonyl (PC, 4-hydroxynonenal protein adduct (4-HNE, oxidized and/or MDA-modified LDL-cholesterol (oxy-LDL/MDA, 8-isoprostanes (8-isoP, and oxidative stress index (OSI were measured at 7 (groups 1 and 3 and 14 (groups 2 and 4 days of experiment. Results. The unstimulated salivary flow in DM rats was reduced in the 2nd week, while the stimulated flow was decreased throughout the duration of the experiment versus control. OSI was elevated in both diabetic glands in the 1st and 2nd week, whereas 8-isoP and 8-OHdG were higher only in the parotid gland in the second week. PC and 4-HNE were increased in the 1st and 2nd week, whereas oxy-LDL/MDA was increased in the 2nd week in the diabetic parotid glands. Conclusions. Diabetes induces oxidative damage of the salivary glands, which seems to be caused by processes taking place in the salivary glands, independently of general oxidative stress. The parotid glands are more vulnerable to oxidative damage in these conditions.

  8. Effect of Mucuna pruriens (Linn.) on mitochondrial dysfunction and DNA damage in epididymal sperm of streptozotocin induced diabetic rat.

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    Suresh, Sekar; Prithiviraj, Elumalai; Lakshmi, Nagella Venkata; Ganesh, Mohanraj Karthik; Ganesh, Lakshmanan; Prakash, Seppan

    2013-01-09

    Mucuna pruriens Linn. (M. pruriens) is a leguminous plant that has been recognized as an herbal medicine for improving fertility and related disorders in the Indian traditional system of medicine, however without proper scientific validations. To study the effect of ethanolic seed extract of M. pruriens on mitochondrial dysfunction and the DNA damage in hyperglycemic rat epididymal spermatozoa. Male Wistar albino rats were divided as control (Sham), diabetes induced [streptozotocin 60 mg/kg of body weight (b.w.) in 0.1M citrate buffer] (STZ), diabetic rats administered with 200mg/kg b.w. of extract (STZ+MP) and normal rats administered with 200mg/kg b.w. of extract (Sham+MP). M. pruriens was administered (gavage) once daily for a period of 60 days. On 60th day animals were sacrificed by cervical dislocation sperm were collected from epididymis and subjected various analysis like antioxidants, ROS, lipid peroxidation (LPO), DNA damage, chromosomal integrity and mitochondrial membrane potential (MMP). Significant reduction in the sperm count, motility, viability and significant increase in the number of abnormal sperm in STZ compared to sham was noticed. STZ rat sperm showed significant increase in LPO and DNA damage. Both the enzymic and non-enzymic were decreased; MMP and the mitochondrial functions were severely affected in STZ group. The diabetic rats supplemented with M. pruriens showed a remarkable recovery in antioxidant levels and reduced LPO with well preserved sperm DNA. MMP and mitochondrial function test were also preserved in STZ+MP rat sperm. The present study has clearly demonstrated the potency of M. pruriens to reduce the diabetic induced sperm damage induced by oxidative stress (OS). These observations are encouraging to perform similar studies in human. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  9. Sulforaphane protects against cytokine- and streptozotocin-induced β-cell damage by suppressing the NF-κB pathway

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    Song, Mi-Young; Kim, Eun-Kyung; Moon, Woo-Sung; Park, Jin-Woo; Kim, Hyung-Jin; So, Hong-Seob; Park, Raekil; Kwon, Kang-Beom; Park, Byung-Hyun

    2009-01-01

    Sulforaphane (SFN) is an indirect antioxidant that protects animal tissues from chemical or biological insults by stimulating the expression of several NF-E2-related factor-2 (Nrf2)-regulated phase 2 enzymes. Treatment of RINm5F insulinoma cells with SFN increases Nrf2 nuclear translocation and expression of phase 2 enzymes. In this study, we investigated whether the activation of Nrf2 by SFN treatment or ectopic overexpression of Nrf2 inhibited cytokine-induced β-cell damage. Treatment of RIN cells with IL-1β and IFN-γ induced β-cell damage through a NF-κB-dependent signaling pathway. Activation of Nrf2 by treatment with SFN and induction of Nrf2 overexpression by transfection with Nrf2 prevented cytokine toxicity. The mechanism by which Nrf2 activation inhibited NF-κB-dependent cell death signals appeared to involve the reduction of oxidative stress, as demonstrated by the inhibition of cytokine-induced H 2 O 2 production. The protective effect of SFN was further demonstrated by the restoration of normal insulin secreting responses to glucose in cytokine-treated rat pancreatic islets. Furthermore, pretreatment with SFN blocked the development of type 1 diabetes in streptozotocin-treated mice

  10. Low Protein Diet Inhibits Uric Acid Synthesis and Attenuates Renal Damage in Streptozotocin-Induced Diabetic Rats

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    Jianmin Ran

    2014-01-01

    Full Text Available Aim. Several studies indicated that hyperuricemia may link to the worsening of diabetic nephropathy (DN. Meanwhile, low protein diet (LPD retards exacerbation of renal damage in chronic kidney disease. We then assessed whether LPD influences uric acid metabolism and benefits the progression of DN in streptozotocin- (STZ- induced diabetic rats. Methods. STZ-induced and control rats were both fed with LPD (5% and normal protein diet (18%, respectively, for 12 weeks. Vital signs, blood and urinary samples for UA metabolism were taken and analyzed every 3 weeks. Kidneys were removed at the end of the experiment. Results. Diabetic rats developed into constantly high levels of serum UA (SUA, creatinine (SCr and 24 h amounts of urinary albumin excretion (UAE, creatintine (UCr, urea nitrogen (UUN, and uric acid (UUA. LPD significantly decreased SUA, UAE, and blood glucose, yet left SCr, UCr, and UUN unchanged. A stepwise regression showed that high UUA is an independent risk factor for DN. LPD remarkably ameliorated degrees of enlarged glomeruli, proliferated mesangial cells, and hyaline-degenerated tubular epithelial cells in diabetic rats. Expression of TNF-α in tubulointerstitium significantly decreased in LPD-fed diabetic rats. Conclusion. LPD inhibits endogenous uric acid synthesis and might accordingly attenuate renal damage in STZ-induced diabetic rats.

  11. Psoralea corylifolia L. Seed Extract Ameliorates Streptozotocin-Induced Diabetes in Mice by Inhibition of Oxidative Stress

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    Eunhui Seo

    2014-01-01

    Full Text Available Pancreatic beta-cell death is known to be the cause of deficient insulin production in diabetes mellitus. Oxidative stress is one of the major causes of beta-cell death. In this study, we investigated the effects of Psoralea corylifolia L. seed (PCS extract on beta-cell death. Oral administration of PCS extract resulted in a significant improvement of hyperglycemia in streptozotocin-induced diabetic mice. PCS extract treatment improved glucose tolerance and increased serum insulin levels. To study the mechanisms involved, we investigated the effects of PCS extract on H2O2-induced apoptosis in INS-1 cells. Treatment with PCS extract inhibited cell death. PCS extract treatment decreased reactive oxygen species level and activated antioxidative enzymes. Among the major components of PCS extract, psoralen and isopsoralen (coumarins, but not bakuchiol, showed preventive effects against H2O2-induced beta-cell death. These findings indicate that PCS extract may be a potential pharmacological agent to protect against pancreatic beta-cell damage caused by oxidative stress associated with diabetes.

  12. Extract of Bauhinia vahlii Shows Antihyperglycemic Activity, Reverses Oxidative Stress, and Protects against Liver Damage in Streptozotocin-induced Diabetic Rats

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    Elbanna, Ahmed H.; Nooh, Mohammed M.; Mahrous, Engy A.; Khaleel, Amal E.; Elalfy, Taha S.

    2017-01-01

    strong α-glucosidase inhibition while the nonpolar fraction (n-hexane extract) failed to show any activity in both assays. DEE was further investigated in streptozotocin-induced diabetic rat model where oral administration of DEE at 2 doses (150 and 300 mg/kg) for 4 weeks resulted in significant reduction in fasting blood glucose and glycated hemoglobin and reversal of oxidative stress signs as indicated by measurement of hepatic reduced glutathione, nitric oxide, and malondialdehyde levels. In addition, histopathological examination and measurement of serum aspartate transaminase and alanine transaminase levels showed that DEE protected the liver from signs of pathogenesis observed in diabetic untreated rats. Phytochemical analysis of DEE showed high flavonoid content with quercitrin as the major constituent (62.9 ± 0.18 mg/mg). Abbreviations used: ALT: Alanine transaminase, AST: Aspartate transaminase, DEE: Defatted ethanol extract, DPPH: 2,2-diphenyl-1-picrylhydrazyl, FBG: Fasting blood glucose, GAE: Gallic acid equivalent, GSH: Reduced glutathione, Hb1Ac: Glycated hemoglobin, HE: Hexane extract MDA: Malondialdehyde, QE: Quercetin equivalent, STZ: Streptozotocin, TAC: Total antioxidant capacity. PMID:29142421

  13. [Factors causing damage and destruction of beta-cells of the islets of Langerhans in the pancreas].

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    Anděl, Michal; Němcová, Vlasta; Pavlíková, Nela; Urbanová, Jana; Cecháková, Marie; Havlová, Andrea; Straková, Radka; Večeřová, Livia; Mandys, Václav; Kovář, Jan; Heneberg, Petr; Trnka, Jan; Polák, Jan

    2014-09-01

    Insulin secretion in patients with manifested diabetes mellitus tends to disappear months to decades after the diagnosis, which is a clear sign of a gradual loss of pancreatic islet beta-cells. In our sample of 30 type 2 diabetic patients, whose disease manifested between 30 and 45 years of age, about a half have retained or even increased insulin secretion 30 years later, while the other half exhibit a much diminished or lost insulin secretion. Factors that can damage or destroy beta-cells can be divided into the following groups: Metabolic factors: hyperglycemia and glucotoxicity, lipotoxicity, hypoxia, reactive oxygen species; Pharmacological factors: antimicrobial medication pentamidine, SSRI antidepressants; Factors related to impaired insulin secretion: MODY type diabetes; Environmental toxic factors: rat poison Vacor, streptozotocin, polychlorinated and polybrominated hydrocarbons; Disorders of the exocrine pancreas: tumor infiltration, fibrous infiltration, chronic pancreatitis, cystic fibrosis; Infections, inflammation, autoimmunity, viral factors: Coxsackie viruses, H1N1 influenza, enteroviruses. We are currently working on finding other factors leading to beta-cell damage, studying their effect on apoptosis and necrosis and looking for possible protective factors to prevent this damage. We our increasing knowledge about the mechanisms of beta-cell damage and destruction we come ever closer to suggest measures for their prevention. In this review we offer a brief and simplified summary of some of the findings related to this area.Key words: pancreatic islet beta-cells of Langerhans - factors damaging or destroying beta-cells - insulin secretion.

  14. Deletion of the Men1 Gene Prevents Streptozotocin-Induced Hyperglycemia in Mice

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    Yuqing Yang

    2010-01-01

    Full Text Available Diabetes ultimately results from an inadequate number of functional beta cells in the islets of Langerhans. Enhancing proliferation of functional endogenous beta cells to treat diabetes remains underexplored. Here, we report that excision of the Men1 gene, whose loss-of-function mutation leads to inherited multiple endocrine neoplasia type 1 (MEN1, rendered resistant to streptozotocin-induced hyperglycemia in a tamoxifen-inducible and temporally controlled Men1 excision mouse model as well as in a tissue-specific Men1 excision mouse model. Men1 excision prevented mice from streptozotocin-induced hyperglycemia mainly through increasing the number of functional beta cells. BrdU incorporation by beta cells, islet size, and circulating insulin levels were significantly increased in Men1-excised mice. Membrane localization of glucose transporter 2 was largely preserved in Men1-excised beta cells, but not in Men1-expressing beta cells. Our findings suggest that repression of menin, a protein encoded by the Men1 gene, might be a valuable means to maintain or increase the number of functional endogenous beta cells to prevent or ameliorate diabetes.

  15. Hyperglycemia in Streptozotocin-Induced Diabetes Leads to Persistent Inflammation and Tissue Damage Following Uveitis Due to Reduced Levels of Ciliary Body Heme Oxygenase-1

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    2006-01-01

    Full Text Available This study investigated the heme oxygenase-1 (HO-1 and the endotoxin-induced uveitis (EIU in diabetic streptozotocin (STZ-hyperglycemic rats. STZ-hyperglycemic rats had impaired levels of the enzyme HO-1 within the ciliary bodies if compared with the nondiabetic rats. STZ-hyperglycemic rats also predisposed the eye to produce high levels of both the cytokines IL-1 β and CXCL8. Subsequent EIU further and significantly P<.01 increased the cytokines production, an effect partly prevented by hemin treatment. Most importantly, hemin, an inducer of heme oxygenase expression and activity, recovered the huge number of infiltrated polymorphonuclear leukocytes PMN within the ciliary bodies associated with STZ-hyperglycemic state and EIU damage. Impairment of the stress-sensitive enzyme HO-1 in STZ-hyperglycemic rats increases and prolongs the inflammatory response to EIU.

  16. The anti-inflammatory and antifibrotic effects of Coreopsis tinctoria Nutt on high-glucose-fat diet and streptozotocin-induced diabetic renal damage in rats.

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    Yao, Lan; Li, Linlin; Li, Xinxia; Li, Hui; Zhang, Yujie; Zhang, Rui; Wang, Jian; Mao, Xinmin

    2015-09-07

    Diabetic nephropathy is a serious complication of diabetes whose development process is associated with inflammation, renal hypertrophy, and fibrosis. Coreopsis tinctoria Nutt, traditionally used as a healthcare tea, has anti-inflammatory, anti-hyperlipidemia, and glycemic regulation activities. The aim of our study was to investigate the renal protective effect of ethyl acetate extract of C. tinctoria Nutt (AC) on high-glucose-fat diet and streptozotocin (STZ)-induced diabetic rats. A diabetic rat model was induced by high-glucose-fat diet and intraperitoneal injection of 35 mg/kg STZ. After treatment with AC at a daily dose of 150, 300 or, 600 mg/kg for 4 weeks, metabolic and renal function parameters of serum and urine were examined. Degree of renal damage, renal proinflammatory cytokines, and fibrotic protein expression were analyzed by histopathology and immunohistochemistry. Renal AMP-activated protein kinase (AMPK) and transforming growth factor (TGF)-β1/Smad signaling pathway were determined by western blotting. Diabetic rats showed obvious renal dysfunction, inflammation and fibrosis. However, AC significantly reduced levels of blood glucose, total cholesterol, triglyceride, blood urea nitrogen, serum creatinine and urinary albumin, as well as expression of kidney proinflammatory cytokines of monocyte chemoattractant protein-1 and intercellular adhesion molecule-1. AC also ameliorated renal hypertrophy and fibrosis by reducing fibronectin and collagen IV and suppressing the TGF-β1/Smad signaling pathway. Meanwhile, AMPKα as a protective cytokine was markedly stimulated by AC. In summary, AC controls blood glucose, inhibits inflammatory and fibrotic processes, suppresses the TGF-β1/Smad signaling pathway, and activates phosphorylation of AMPKα in the kidneys, which confirms the protective effects of AC in the early stage of diabetic kidney disease.

  17. EX4 stabilizes and activates Nrf2 via PKCδ, contributing to the prevention of oxidative stress-induced pancreatic beta cell damage

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    Kim, Mi-Hwi; Kim, Eung-Hwi [College of Pharmacy, Gachon Institute of Pharmaceutical Science, Gachon University, Yeonsu-ku, Incheon (Korea, Republic of); Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Yeonsu-ku, Incheon (Korea, Republic of); Jung, Hye Seung [Department of Internal Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of); Yang, Dongki [Department of Physiology, Gachon University College of Medicine, Incheon (Korea, Republic of); Park, Eun-Young, E-mail: parkey@mokpo.ac.kr [College of Pharmacy, Natural Medicine Research Institute, Mokpo National University, Muan-gun, Jeonnam (Korea, Republic of); Jun, Hee-Sook, E-mail: hsjun@gachon.ac.kr [College of Pharmacy, Gachon Institute of Pharmaceutical Science, Gachon University, Yeonsu-ku, Incheon (Korea, Republic of); Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Yeonsu-ku, Incheon (Korea, Republic of); Gachon Medical Research Institute, Gil Hospital, Incheon (Korea, Republic of)

    2017-01-15

    Oxidative stress in pancreatic beta cells can inhibit insulin secretion and promote apoptotic cell death. Exendin-4 (EX4), a glucagon-like peptide-1 receptor agonist, can suppress beta cell apoptosis, improve beta cell function and protect against oxidative damage. In this study, we investigated the molecular mechanisms for antioxidative effects of EX4 in pancreatic beta cells. INS-1 cells, a rat insulinoma cell line, were pretreated with EX4 and exposed to palmitate or H{sub 2}O{sub 2}. Reactive oxygen species (ROS) production, and glutathione and insulin secretion were measured. The mRNA and protein expression levels of antioxidant genes were examined. The level of nuclear factor erythroid 2-related factor 2 (Nrf2), its binding to antioxidant response element (ARE), and its ubiquination in the presence of EX4 were determined. The Nrf2 signaling pathway was determined using rottlerin (protein kinase [PK]Cδ inhibitor), H89 (PKA inhibitor) and LY294002 (phosphatidylinositide 3-kinase [PI3K] inhibitor). EX4 treatment decreased ROS production, recovered cellular glutathione levels and insulin secretion in the presence of oxidative stress in INS-1 cells. The expression levels of glutamate-cysteine ligase catalytic subunit and heme oxygenase-1 were increased by EX4 treatment. EX4 promoted Nrf2 translocation, ARE binding activity and enhanced stabilization of Nrf2 by inhibition of ubiquitination. Knockdown of Nrf2 abolished the effect of EX4 on increased insulin secretion. Inhibition of PKCδ attenuated Nrf2 translocation and antioxidative gene expression by EX4 treatment. We suggest that EX4 activates and stabilizes Nrf2 through PKCδ activation, contributing to the increase of antioxidant gene expression and consequently improving beta cell function in the presence of oxidative stress. - Highlights: • EX4 protects against oxidative stress-induced pancreatic beta cell dysfunction. • EX4 increases antioxidant gene expression. • Antioxidative effect of EX4 is

  18. EX4 stabilizes and activates Nrf2 via PKCδ, contributing to the prevention of oxidative stress-induced pancreatic beta cell damage

    International Nuclear Information System (INIS)

    Kim, Mi-Hwi; Kim, Eung-Hwi; Jung, Hye Seung; Yang, Dongki; Park, Eun-Young; Jun, Hee-Sook

    2017-01-01

    Oxidative stress in pancreatic beta cells can inhibit insulin secretion and promote apoptotic cell death. Exendin-4 (EX4), a glucagon-like peptide-1 receptor agonist, can suppress beta cell apoptosis, improve beta cell function and protect against oxidative damage. In this study, we investigated the molecular mechanisms for antioxidative effects of EX4 in pancreatic beta cells. INS-1 cells, a rat insulinoma cell line, were pretreated with EX4 and exposed to palmitate or H 2 O 2 . Reactive oxygen species (ROS) production, and glutathione and insulin secretion were measured. The mRNA and protein expression levels of antioxidant genes were examined. The level of nuclear factor erythroid 2-related factor 2 (Nrf2), its binding to antioxidant response element (ARE), and its ubiquination in the presence of EX4 were determined. The Nrf2 signaling pathway was determined using rottlerin (protein kinase [PK]Cδ inhibitor), H89 (PKA inhibitor) and LY294002 (phosphatidylinositide 3-kinase [PI3K] inhibitor). EX4 treatment decreased ROS production, recovered cellular glutathione levels and insulin secretion in the presence of oxidative stress in INS-1 cells. The expression levels of glutamate-cysteine ligase catalytic subunit and heme oxygenase-1 were increased by EX4 treatment. EX4 promoted Nrf2 translocation, ARE binding activity and enhanced stabilization of Nrf2 by inhibition of ubiquitination. Knockdown of Nrf2 abolished the effect of EX4 on increased insulin secretion. Inhibition of PKCδ attenuated Nrf2 translocation and antioxidative gene expression by EX4 treatment. We suggest that EX4 activates and stabilizes Nrf2 through PKCδ activation, contributing to the increase of antioxidant gene expression and consequently improving beta cell function in the presence of oxidative stress. - Highlights: • EX4 protects against oxidative stress-induced pancreatic beta cell dysfunction. • EX4 increases antioxidant gene expression. • Antioxidative effect of EX4 is mediated by

  19. Urtica Dioica Distillate Regenerates Pancreatic Beta Cells in Streptozotocin-Induced Diabetic Rats

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    Gohari, Ali; Noorafshan, Ali; Akmali, Masoumeh; Zamani-Garmsiri, Fahimeh; Seghatoleslam, Atefeh

    2018-01-01

    Background Urtica dioica is known as an anti-hyperglycemic plant. Urtica dioica distillate (UD) is a traditional Iranian drink, locally known as “aragh gazaneh”. In spite of its widespread consumption in Iran, according to traditional Iranian medicine, there is no scientific report on the usefulness of UD for diabetic patients. This survey was designed to evaluate its protective effects for the recovery from diabetes by determining the serum insulin, blood glucose, volume of pancreatic islets, and the number and volume of β-cells in diabetic rats. Methods A total of 48 Sprague-Dawley male rats (200-250 g) were randomly distributed into 6 groups (n=8), including non-diabetic plus distilled water (DW), non-diabetic plus UD, diabetic plus DW, diabetic plus UD, diabetic plus insulin, and diabetic plus glibenclamide. DW, UD, and glibenclamide were administered via intragastric gavage and insulin was injected subcutaneously. After four weeks of experiments, blood samples were collected for serum insulin and blood glucose assay. Pancreas was also evaluated using stereological method. The SPSS software was used for statistical analysis. Kruskal-Wallis, repeated measurements, and Mann-Whitney U test were applied for comparisons between the groups. Results The treatment of diabetic rats with UD reduced the blood glucose dramatically (P<0.001) and increased serum insulin levels significantly (P=0.03) in comparison to the diabetic plus DW rats. Treatment with UD did not affect the mean β-cell volumes in the diabetic rats when compared to the diabetic plus DW rats, but the islet volumes and β-cell numbers were significantly recovered. Conclusion UD treatment in diabetic rats improves hyperglycemia by partially restoring plasma insulin levels. The data suggest that UD prevents islet atrophy and/or regenerate pancreatic β-cells. PMID:29749986

  20. Fetal and neonatal nicotine exposure in Wistar rats causes progressive pancreatic mitochondrial damage and beta cell dysfunction.

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    Jennifer E Bruin

    Full Text Available Nicotine replacement therapy (NRT is currently recommended as a safe smoking cessation aid for pregnant women. However, fetal and neonatal nicotine exposure in rats causes mitochondrial-mediated beta cell apoptosis at weaning, and adult-onset dysglycemia, which we hypothesize is related to progressive mitochondrial dysfunction in the pancreas. Therefore in this study we examined the effect of fetal and neonatal exposure to nicotine on pancreatic mitochondrial structure and function during postnatal development. Female Wistar rats were given saline (vehicle control or nicotine bitartrate (1 mg/kg/d via subcutaneous injection for 2 weeks prior to mating until weaning. At 3-4, 15 and 26 weeks of age, oral glucose tolerance tests were performed, and pancreas tissue was collected for electron microscopy, enzyme activity assays and islet isolation. Following nicotine exposure mitochondrial structural abnormalities were observed beginning at 3 weeks and worsened with advancing age. Importantly the appearance of these structural defects in nicotine-exposed animals preceded the onset of glucose intolerance. Nicotine exposure also resulted in significantly reduced pancreatic respiratory chain enzyme activity, degranulation of beta cells, elevated islet oxidative stress and impaired glucose-stimulated insulin secretion compared to saline controls at 26 weeks of age. Taken together, these data suggest that maternal nicotine use during pregnancy results in postnatal mitochondrial dysfunction that may explain, in part, the dysglycemia observed in the offspring from this animal model. These results clearly indicate that further investigation into the safety of NRT use during pregnancy is warranted.

  1. DNA protective effects of melatonin on oxidative stress in streptozotocin - induced diabetic rats.

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    Selim Sekkin

    2015-05-01

    the antioxidant system, MEL regulates the expression of several genes such as those of superoxide dismutase (SOD and glutathione peroxidase (2-4. The aim of this study was to research the effects of MEL on oxidative stress and DNA protective effects in streptozotocin-induced diabetic rats. A total of 32 rats were equally divided into 4 experimental groups as Control, Melatonin, Diabetic, and Diabetic + Melatonin. A pancreatic beta-cell cytotoxic agent, single dose streptozotocin (60 mg/kg was given by intraperitoneal route to induce experimental diabetes in rats. Rats with ≥200mg/dL blood glucose level were established as Diabetic and Diabetic + Melatonin groups. MEL (10 mg/kg per day and sodium citrate solution were administrated to rats by intraperitoneal route for 6 weeks. With the termination of the experiment, tissue and blood samples were obtained for further analysis. SOD, catalase (CAT, reduced glutathione (GSH and malondialdehyde (MDA were evaluated in rat liver, renal, brain and pancreas tissues. Body weight, plasma glucose, and %HbA1c levels were studied. DNA damage was analyzed with the comet assay in rat lymphocytes; %Tail DNA and Mean Tail Moment parameters were evaluated (5. Antioxidant and oxidant enzyme levels were similar in the Control and Melatonin groups, although there were significant differences between the Diabetic and Diabetic + Melatonin groups. SOD levels in brain and liver tissues were higher (P<0,001, and CAT activities in renal tissue (P<0,001, GSH levels in pancreas tissue (P<0,01 as well as MDA levels in liver (P<0,001, renal (P<0,001 and brain (P<0,01 tissues were higher in the Diabetic + Melatonin group compared with the Diabetic group. Body weight changes and blood glucose levels of the rats were evaluated during the 6 weeks. The effect of MEL on the body weights of Control and Melatonin as well as Diabetic and Diabetic + Melatonin group rats were similar. MEL had no effect on body weight and the diabetic rats were lighter (P<0

  2. Beta cell adaptation in pregnancy

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    2016-01-01

    Pregnancy is associated with a compensatory increase in beta cell mass. It is well established that somatolactogenic hormones contribute to the expansion both indirectly by their insulin antagonistic effects and directly by their mitogenic effects on the beta cells via receptors for prolactin...... and growth hormone expressed in rodent beta cells. However, the beta cell expansion in human pregnancy seems to occur by neogenesis of beta cells from putative progenitor cells rather than by proliferation of existing beta cells. Claes Hellerström has pioneered the research on beta cell growth for decades...... in the expansion of the beta cell mass in human pregnancy, and the relative roles of endocrine factors and nutrients....

  3. Regulation of beta cell replication

    DEFF Research Database (Denmark)

    Lee, Ying C; Nielsen, Jens Høiriis

    2008-01-01

    Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

  4. Cdk5 inhibitory peptide (CIP inhibits Cdk5/p25 activity induced by high glucose in pancreatic beta cells and recovers insulin secretion from p25 damage.

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    Ya-Li Zheng

    Full Text Available Cdk5/p25 hyperactivity has been demonstrated to lead to neuron apoptosis and degenerations. Chronic exposure to high glucose (HG results in hyperactivity of Cdk5 and reduced insulin secretion. Here, we set out to determine whether abnormal upregulation of Cdk5/p25 activity may be induced in a pancreatic beta cell line, Min6 cells. We first confirmed that p25 were induced in overexpressed p35 cells treated with HG and increased time course dependence. Next, we showed that no p25 was detected under short time HG stimulation (4-12 hrs, however was detectable in the long exposure in HG cells (24 hrs and 48 hrs. Cdk5 activity in the above cells was much higher than low glucose treated cells and resulted in more than 50% inhibition of insulin secretion. We confirmed these results by overexpression of p25 in Min6 cells. As in cortical neurons, CIP, a small peptide, inhibited Cdk5/p25 activity and restored insulin secretion. The same results were detected in co-infection of dominant negative Cdk5 (DNCdk5 with p25. CIP also reduced beta cells apoptosis induced by Cdk5/p25. These studies indicate that Cdk5/p25 hyperactivation deregulates insulin secretion and induces cell death in pancreatic beta cells and suggests that CIP may serve as a therapeutic agent for type 2 diabetes.

  5. Caffeine at a Moderate Dose Did Not Affect the Skeletal System of Rats with Streptozotocin-Induced Diabetes.

    Science.gov (United States)

    Folwarczna, Joanna; Janas, Aleksandra; Cegieła, Urszula; Pytlik, Maria; Śliwiński, Leszek; Matejczyk, Magdalena; Nowacka, Anna; Rudy, Karolina; Krivošíková, Zora; Štefíková, Kornélia; Gajdoš, Martin

    2017-10-30

    Diabetes may lead to the development of osteoporosis. Coffee drinking, apart from its health benefits, is taken into consideration as an osteoporosis risk factor. Data from human and animal studies on coffee and caffeine bone effects are inconsistent. The aim of the study was to investigate effects of caffeine at a moderate dose on the skeletal system of rats in two models of experimental diabetes induced by streptozotocin. Effects of caffeine administered orally (20 mg/kg aily for four weeks) were investigated in three-month-old female Wistar rats, which, two weeks before the start of caffeine administration, received streptozotocin (60 mg/kg, intraperitoneally) alone or streptozotocin after nicotinamide (230 mg/kg, intraperitoneally). Bone turnover markers, mass, mineral density, histomorphometric parameters, and mechanical properties were examined. Streptozotocin induced diabetes, with profound changes in the skeletal system due to increased bone resorption and decreased bone formation. Although streptozotocin administered after nicotinamide induced slight increases in glucose levels at the beginning of the experiment only, slight, but significant unfavorable changes in the skeletal system were demonstrated. Administration of caffeine did not affect the investigated skeletal parameters of rats with streptozotocin-induced disorders. In conclusion, caffeine at a moderate dose did not exert a damaging effect on the skeletal system of diabetic rats.

  6. Caffeine at a Moderate Dose Did Not Affect the Skeletal System of Rats with Streptozotocin-Induced Diabetes

    Directory of Open Access Journals (Sweden)

    Joanna Folwarczna

    2017-10-01

    Full Text Available Diabetes may lead to the development of osteoporosis. Coffee drinking, apart from its health benefits, is taken into consideration as an osteoporosis risk factor. Data from human and animal studies on coffee and caffeine bone effects are inconsistent. The aim of the study was to investigate effects of caffeine at a moderate dose on the skeletal system of rats in two models of experimental diabetes induced by streptozotocin. Effects of caffeine administered orally (20 mg/kg aily for four weeks were investigated in three-month-old female Wistar rats, which, two weeks before the start of caffeine administration, received streptozotocin (60 mg/kg, intraperitoneally alone or streptozotocin after nicotinamide (230 mg/kg, intraperitoneally. Bone turnover markers, mass, mineral density, histomorphometric parameters, and mechanical properties were examined. Streptozotocin induced diabetes, with profound changes in the skeletal system due to increased bone resorption and decreased bone formation. Although streptozotocin administered after nicotinamide induced slight increases in glucose levels at the beginning of the experiment only, slight, but significant unfavorable changes in the skeletal system were demonstrated. Administration of caffeine did not affect the investigated skeletal parameters of rats with streptozotocin-induced disorders. In conclusion, caffeine at a moderate dose did not exert a damaging effect on the skeletal system of diabetic rats.

  7. Extract of Moringa oleifera leaves ameliorates streptozotocin-induced Diabetes mellitus in adult rats.

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    Yassa, Hanan Dawood; Tohamy, Adel Fathy

    2014-06-01

    Medicinal plants attract growing interest in the therapeutic management of Diabetes mellitus. Moringa oleifera is a remarkably nutritious vegetable with several antioxidant properties. The present study assessed the possible antioxidant and antidiabetic effects of an aqueous extract of M. oleifera leaves in treating streptozotocin-induced diabetic albino rats. The antidiabetic effects of aqueous extract of M. oleifera leaves were assessed histomorphometrically, ultrastructurally and biochemically. Fasting plasma glucose (FPG) was monitored and morphometric measurements of β-cells of islets of Langerhans (modified Gomori's stain) and collagen fibers (Mallory's trichrome stain) were performed. The antioxidant effects of M. oleifera leaves were determined by measuring the reduced glutathione and lipid peroxidation product, malondialdehyde, in pancreatic tissue. M. oleifera treatment significantly ameliorated the altered FPG (from 380% to 145%), reduced glutathione (from 22% to 73%) and malondialdehyde (from 385% to 186%) compared to control levels. The histopathological damage of islet cells was also markedly reversed. Morphometrically, M. oleifera significantly increased the areas of positive purple modified Gomori stained β-cells (from 60% to 91%) and decreased the area percentage of collagen fibers (from 199% to 120%) compared to control values. Experimental findings clearly indicate the potential benefits of using the aqueous extract of M. oleifera leaves as a potent antidiabetic treatment. Copyright © 2014 Elsevier GmbH. All rights reserved.

  8. Visualizing pancreatic {beta}-cell mass with [{sup 11}C]DTBZ

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    Simpson, Norman Ray [Department of Radiology, Columbia University Medical School, New York, NY 10032 (United States); Souza, Fabiola [Department of Surgery, Columbia University Medical School, New York, NY 10032 (United States); Witkowski, Piotr [Department of Medicine, Columbia University Medical School, New York, NY 10032 (United States); Maffei, Antonella [Institute of Genetics and Biophysics ' Adriano Buzzati-Traverso' , CNR, Naples 80131 (Italy); Raffo, Anthony [Department of Surgery, Columbia University Medical School, New York, NY 10032 (United States); Herron, Alan [Center for Comparative Medicine and The Department of Pathology, Baylor College of Medicine, Houston, TX 77030 (United States); Kilbourn, Michael [Department of Radiology, University of Michigan, Ann Arbor, MI 48109-0638 (United States); Jurewicz, Agata [Department of Radiology, Columbia University Medical School, New York, NY 10032 (United States); Herold, Kevan [Department of Surgery, Columbia University Medical School, New York, NY 10032 (United States); Liu, Eric [Diabetes Branch, NIDDK, National Institutes of Health, Bethesda, MD 20854 (United States); Hardy, Mark Adam [Department of Medicine, Columbia University Medical School, New York, NY 10032 (United States); Van Heertum, Ronald [Department of Radiology, Columbia University Medical School, New York, NY 10032 (United States); Harris, Paul Emerson [Department of Surgery, Columbia University Medical School, New York, NY 10032 (United States)]. E-mail: peh1@columbia.edu

    2006-10-15

    {beta}-Cell mass (BCM) influences the total amount of insulin secreted, varies by individual and by the degree of insulin resistance, and is affected by physiologic and pathologic conditions. The islets of Langerhans, however, appear to have a reserve capacity of insulin secretion and, overall, assessments of insulin and blood glucose levels remain poor measures of BCM, {beta}-cell function and progression of diabetes. Thus, novel noninvasive determinations of BCM are needed to provide a quantitative endpoint for novel therapies of diabetes, islet regeneration and transplantation. Built on previous gene expression studies, we tested the hypothesis that the targeting of vesicular monoamine transporter 2 (VMAT2), which is expressed by {beta} cells, with [{sup 11}C]dihydrotetrabenazine ([{sup 11}C]DTBZ), a radioligand specific for VMAT2, and the use of positron emission tomography (PET) can provide a measure of BCM. In this report, we demonstrate decreased radioligand uptake within the pancreas of Lewis rats with streptozotocin-induced diabetes relative to their euglycemic historical controls. These studies suggest that quantitation of VMAT2 expression in {beta} cells with the use of [{sup 11}C]DTBZ and PET represents a method for noninvasive longitudinal estimates of changes in BCM that may be useful in the study and treatment of diabetes.

  9. In vivo and in vitro evaluation of the effects of Urtica dioica and swimming activity on diabetic factors and pancreatic beta cells.

    Science.gov (United States)

    Ranjbari, Abbas; Azarbayjani, Mohammad Ali; Yusof, Ashril; Halim Mokhtar, Abdul; Akbarzadeh, Samad; Ibrahim, Mohamed Yousif; Tarverdizadeh, Bahman; Farzadinia, Parviz; Hajiaghaee, Reza; Dehghan, Firouzeh

    2016-03-15

    Urtica dioica (UD) has been identified as a traditional herbal medicine. This study aimed to investigate the effect of UD extract and swimming activity on diabetic parameters through in vivo and in vitro experiments. Adult WKY male rats were randomly distributed in nine groups: intact control, diabetic control, diabetic + 625 mg/kg, 1.25 g/kg UD, diabetic + 100 mg/kg Metformin, diabetic + swimming, diabetic + swimming 625 mg/kg, 1.25 g/kg UD, and diabetic +100 mg/kg Metformin + swimming. The hearts of the animals were punctured, and blood samples were collected for biochemical analysis. The entire pancreas was exposed for histologic examination. The effect of UD on insulin secretion by RIN-5F cells in 6.25 or 12.5 mM glucose dose was examined. Glucose uptake by cultured L6 myotubes was determined. The serum glucose concentration decreased, the insulin resistance and insulin sensitivity significantly increased in treated groups. These changes were more pronounced in the group that received UD extract and swimming training. Regeneration and less beta cell damage of Langerhans islets were observed in the treated groups. UD treatment increased insulin secretion in the RIN-5F cells and glucose uptake in the L6 myotubes cells. Swimming exercises accompanied by consuming UD aqueous extracts effectively improved diabetic parameters, repaired pancreatic tissues in streptozotocin-induced diabetics in vivo, and increased glucose uptake or insulin in UD-treated cells in vitro.

  10. Hypoglycemic of Cajanus scarabaeoides in glucose overloaded and streptozotocin-induced diabetic rats

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    Suman Pattanayak, Siva Shankar Nayak, Durgaprasad Panda and Vikas Shende

    2009-12-01

    Full Text Available In light of traditional claim of Cajanus scarabaeoides (L in the treatment of diabetes, we studied the effects of different solvent extracts in normal, glucose over loaded normal rats and streptozotocin-induced diabetic rats. The methanolic extract (500 mg/kg orally was produce significantly reduce blood glucose level at normal, glucose over loaded normal rats, and streptozotocin-induced diabetic rats after 15 days treatment; whereas petroleum ether and chloroform extract (500 mg/kg orally did not exhibit any significant effect on three groups of rats. Histopathology studies on pancreas of streptozotocin-induced diabetic rats shows inflammatory changes in pancreatic islets, results from selective destroy of insulin producing β-cells. These changes are inhibited by C. scarabaeoides methanolic extract and gliclazide. The antidiabetic activity of methanolic extract may be due to the presence of flavonoids.

  11. Effect of opium on glucose metabolism and lipid profiles in rats with streptozotocin-induced diabetes

    NARCIS (Netherlands)

    Sadeghian, Saeed; Boroumand, Mohammad Ali; Sotoudeh-Anvari, Maryam; Rahbani, Shahram; Sheikhfathollahi, Mahmood; Abbasi, Ali

    2009-01-01

    Background: This experimental study was performed to determine the impact of opium use on serum lipid profile and glucose metabolism in rats with streptozotocin-induced diabetes. Material and methods: To determine the effect of opium, 20 male rats were divided into control (n = 10) and opium-treated

  12. Antidiabetic Activity of Different Extracts of Myrtus Communis in Streptozotocin Induced Diabetic Rats

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    Panjeshahin Mohammad Reza

    2016-06-01

    Full Text Available Background and aim: Hydroalcoholic (70° extract of leaves of Myrtus communis has been shown to have antidiabetic effect in streptozotocin induced diabetic rats in our previous study. In this study, we intended to determine the components of the mentioned extract and identify the mechanism for its action.

  13. Effect of the hexane extract of Piper auritum on insulin release from β-cell and oxidative stress in streptozotocin-induced diabetic rat.

    Science.gov (United States)

    Gutierrez, Rosa Martha Perez

    2012-10-01

    The large-leafed perennial plant Piper auritum known as Hoja Santa, is used for its leaves that because of their spicy aromatic scent and flavor have an important presence in Mexican cuisine, and in many regions, this plant is known for its therapeutic properties. In the present study, we investigated the effect of hexane, chloroform and methanol extracts from Piper auritum on cell culture system and the effect in streptozotocin-induced type 1 diabetic rats treated by 28 days on the physiological, metabolic parameters and oxidative stress. The hexane extract of P. auritum (HS) treatment significantly reduced the intake of both food, water and body weight loss as well as levels of blood glucose, serum cholesterol, triglycerides and increase HDL-cholesterol. After 4-week administration of HS antioxidant enzyme as SOD, CAT, GSH, GPx in pancreas were determined. These enzyme increased significantly compared with those of the diabetic rats control and normal animals. For all estimated, the results of HS treated groups leading to a restoration of the defense mechanism. The treatment also improves pancreatic TBARS-reactive substance level and serum NO and iNOS. To determine the insulin releasing activity, after extract treatment the serum and pancreatic sections were processed for examination of insulin-releasing activity using an immunocytochemistry kit. The results showed that administration of the hexane extract (200 and 400 mg/kg) exhibited a significant increase in serum and pancreas tissue insulin. Administration of streptozotocin decreased the insulin secretory activity in comparison with intact rats, but treatment with the HS extract increased significantly the activity of the beta cells in comparison with the diabetic control rats. The extract decreased serum glucose in streptozotocin-induced diabetic rats and increased insulin release from the beta cells of the pancreas. In cultured RIN-5F cells, we examined whether hexane extract of P. auritum would protect the

  14. Beta Cell Workshop 2013 Kyoto

    DEFF Research Database (Denmark)

    Heller, R Scott; Madsen, Ole D; Nielsen, Jens Høiriis

    2013-01-01

    The very modern Kyoto International Conference Center provided the site for the 8th workshop on Beta cells on April 23-26, 2013. The preceding workshops were held in Boston, USA (1991); Kyoto, Japan (1994); Helsingør, Denmark (1997); Helsinki, Finland (2003); El Perello, Spain (2006); Peebles...

  15. Antidiabetic, antioxidant and antihyperlipidemic status of Heliotropium zeylanicum extract on streptozotocin-induced diabetes in rats.

    Science.gov (United States)

    Murugesh, Kandasamy; Yeligar, Veerendra; Dash, Deepak Kumar; Sengupta, Pinaki; Maiti, Bhim Chandra; Maity, Tapan Kumar

    2006-11-01

    The potential role of the methanolic extract of Heliotropium zeylanicum (BURM.F) LAMK (MEHZ) in the treatment of diabetes along with its antioxidant and antihyperlipidemic effects was studied in streptozotocin-induced diabetic rats. Oral administration of (MEHZ) 150 and 300 mg/kg/d for 14 d significantly decreased the blood glucose level and considerably increased the body weight, food intake, and liquid intake of diabetic-induced rats. MEHZ significantly decreased thiobarbituric acid reactive substances and significantly increased reduced glutathione, superoxide dismutase and catalase in streptozotocin-induced diabetic rats at the end of 14 d of treatment. The study also investigated the antihyperlipidemic potential of MEHZ. The results show that the active fraction of MEHZ is promising for development of a standardized phytomedicine for the treatment of diabetes mellitus.

  16. The effect of levosimendan on myocardial ischemia–reperfusion injury in streptozotocin-induced diabetic rats

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    Hasan Ali Kiraz

    2015-12-01

    Full Text Available Objective: Ischemia/reperfusion (I/R injury is an important cause of myocardial damage by means of oxidative, inflammatory, and apoptotic mechanisms. The aim of the present study was to examine the potential cardio protective effects of levosimendan in a diabetic rat model of myocardial I/R injury. Methods: A total of 18 streptozotocin-induced diabetic Wistar Albino rats (55 mg/kg were randomly divided into three equal groups as follows: the diabetic I/R group (DIR in which myocardial I/R was induced following left thoracotomy, by ligating the left anterior descending coronary artery for 60 min, followed by 2 h of reperfusion; the diabetic I/R levosimendan group (DIRL, which underwent I/R by the same method while taking levosimendan intraperitoneal 12 µg kg−1; and the diabetic control group (DC which underwent sham operations without tightening of the coronary sutures. As a control group (C, six healthy age-matched Wistar Albino rats underwent sham operations similar to the DC group. Two hours after the operation, the rats were sacrificed and the myocardial tissue samples were examined by light microscopy for evidence of myonecrosis and inflammatory cell infiltration. Results: Myonecrosis findings were significantly different among groups (p=0.008. Myonecrosis was more pronounced in the DIR group compared with the C, DC, and DIRL groups (p=0.001, p=0.007 and p=0.037, respectively. Similarly, the degree of inflammatory cell infiltration showed significant difference among groups (p<0.0001. Compared with C, DC, and DIRL groups, the inflammatory cell infiltration was significantly higher among the DIR group (p<0.0001, p<0.0001, and p=0.020, respectively. Also, myocardial tissue edema was significantly different among groups (p=0.006. The light microscopic myocardial tissue edema levels were significantly higher in the DIR group than the C, DC, and DIRL groups (p=0.001, p=0.037, and p=0.014, respectively. Conclusion: Taken together, our data

  17. The effect of levosimendan on myocardial ischemia–reperfusion injury in streptozotocin-induced diabetic rats

    Science.gov (United States)

    Kiraz, Hasan Ali; Poyraz, Fatih; Kip, Gülay; Erdem, Özlem; Alkan, Metin; Arslan, Mustafa; Özer, Abdullah; Şivgin, Volkan; Çomu, Faruk Metin

    2015-01-01

    Objective Ischemia/reperfusion (I/R) injury is an important cause of myocardial damage by means of oxidative, inflammatory, and apoptotic mechanisms. The aim of the present study was to examine the potential cardio protective effects of levosimendan in a diabetic rat model of myocardial I/R injury. Methods A total of 18 streptozotocin-induced diabetic Wistar Albino rats (55 mg/kg) were randomly divided into three equal groups as follows: the diabetic I/R group (DIR) in which myocardial I/R was induced following left thoracotomy, by ligating the left anterior descending coronary artery for 60 min, followed by 2 h of reperfusion; the diabetic I/R levosimendan group (DIRL), which underwent I/R by the same method while taking levosimendan intraperitoneal 12 µg kg−1; and the diabetic control group (DC) which underwent sham operations without tightening of the coronary sutures. As a control group (C), six healthy age-matched Wistar Albino rats underwent sham operations similar to the DC group. Two hours after the operation, the rats were sacrificed and the myocardial tissue samples were examined by light microscopy for evidence of myonecrosis and inflammatory cell infiltration. Results Myonecrosis findings were significantly different among groups (p=0.008). Myonecrosis was more pronounced in the DIR group compared with the C, DC, and DIRL groups (p=0.001, p=0.007 and p=0.037, respectively). Similarly, the degree of inflammatory cell infiltration showed significant difference among groups (p<0.0001). Compared with C, DC, and DIRL groups, the inflammatory cell infiltration was significantly higher among the DIR group (p<0.0001, p<0.0001, and p=0.020, respectively). Also, myocardial tissue edema was significantly different among groups (p=0.006). The light microscopic myocardial tissue edema levels were significantly higher in the DIR group than the C, DC, and DIRL groups (p=0.001, p=0.037, and p=0.014, respectively). Conclusion Taken together, our data indicate that

  18. Synergism effects of pioglitazone and Urtica dioica extract in streptozotocin-induced nephropathy via attenuation of oxidative stress

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    Mohammad Shokrzadeh

    2017-05-01

    Full Text Available Objective(s: Hyperglycemia promotes oxidative stress that plays a crucial role in the pathogenesis of Diabetic nephropathy (DN. In this study, we investigated the synergism effects of hydroalcoholic extract of Urtica dioica and pioglitazone (PIO on the prevention of DN in streptozotocin induced-diabetic mice. Materials and Methods: Forty-two mice were divided into six groups as follows: non-diabetic control group, DMSO group (as solvent, diabetic group and four treatment groups which received U. dioica, pioglitazone, U. dioica plus pioglitazone and vitE. Diabetes was induced by a single dose of streptozotocin (STZ (200 mg/kg body wt, IP diluted in citrate buffer (pH= 4.6. After 4 weeks treatment, all animals were anaesthetized and blood was collected for serum urea and creatinine levels assessment in plasma and kidney tissue were excised for evaluation of oxidative stress markers. Results: Treatment with U. dioica significantly inhibited increase in serum urea and creatinine in plasma that were observed in diabetic mice. Furthermore, the elevated level of oxidative stress markers (glutathione oxidation, lipid peroxidation (LPO, protein carbonyl in renal supernatant of diabetic mice was inhibited by U. dioica treatment.  Interestingly, U. dioica promoted beneficial effects of PIO in reducing STZ-induced hyperglycemia, renal damage and oxidative stress markers. Conclusion: Our findings showed that PIO plus U. dioica have synergism protective effects against STZ-induced nephropathy that can be a candidate as a therapeutic approach in order to treatment of DN.

  19. Synergism effects of pioglitazone and Urtica dioica extract in streptozotocin-induced nephropathy via attenuation of oxidative stress.

    Science.gov (United States)

    Shokrzadeh, Mohammad; Sadat-Hosseini, Sara; Fallah, Marjan; Shaki, Fatemeh

    2017-05-01

    Hyperglycemia promotes oxidative stress that plays a crucial role in the pathogenesis of Diabetic nephropathy (DN). In this study, we investigated the synergism effects of hydroalcoholic extract of Urtica dioica and pioglitazone (PIO) on the prevention of DN in streptozotocin induced-diabetic mice. Forty-two mice were divided into six groups as follows: non-diabetic control group, DMSO group (as solvent), diabetic group and four treatment groups which received U. dioica , pioglitazone, U. dioica plus pioglitazone and vitE. Diabetes was induced by a single dose of streptozotocin (STZ) (200 mg/kg body wt, IP) diluted in citrate buffer (pH= 4.6). After 4 weeks treatment, all animals were anaesthetized and blood was collected for serum urea and creatinine levels assessment in plasma and kidney tissue were excised for evaluation of oxidative stress markers. Treatment with U. dioica significantly inhibited increase in serum urea and creatinine in plasma that were observed in diabetic mice. Furthermore, the elevated level of oxidative stress markers (glutathione oxidation, lipid peroxidation (LPO), protein carbonyl) in renal supernatant of diabetic mice was inhibited by U. dioica treatment. Interestingly, U. dioica promoted beneficial effects of PIO in reducing STZ-induced hyperglycemia, renal damage and oxidative stress markers. Our findings showed that PIO plus U. dioica have synergism protective effects against STZ-induced nephropathy that can be a candidate as a therapeutic approach in order to treatment of DN.

  20. Therapeutic Effects of Bupleurum Polysaccharides in Streptozotocin Induced Diabetic Mice.

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    Lingyu Pan

    Full Text Available Diabetes mellitus is related to low-grade chronic inflammation and oxidative stress. Bupleurum Polysaccharides (BPs, isolated from Bupleurum smithii var. parvifolium has anti-inflammatory and anti-oxidative properties. However, little is known about its therapeutic effects on diabetes. In this experiment, the effects of BPs on alleviation of diabetes and the underlying mechanisms were investigated. Diabetic mice model was established via successive intraperitoneal injections of streptozotocin (100 mg/kg body weight for two days. Mice with blood glucose levels higher than 16.8mmol/L were selected for experiments. The diabetic mice were orally administered with BPs (30 and 60 mg/kg once a day for 35 days. BPs not only significantly decreased levels of blood glucose, but also increased those of serum insulin and liver glycogen in diabetic mice compared to model mice. Additionally, BPs adminstration improved the insulin expression and suppressed the apoptosis in pancreas of the diabetic mice. Histopathological observations further demonstrated that BPs protected the pancreas and liver from oxidative and inflammatory damages. These results suggest that BPs protect pancreatic β cells and liver hepatocytes and ameliorate diabetes, which is associated with its anti-oxidative and anti-inflammatory properties.

  1. Dose-dependent effects of dihydrotestosterone in the streptozotocin-induced diabetic rat kidney

    OpenAIRE

    Xu, Qin; Prabhu, Anjali; Xu, Shujing; Manigrasso, Michaele B.; Maric, Christine

    2009-01-01

    We recently reported that castration exacerbates albuminuria, glomerulosclerosis, and tubulointerstitial fibrosis associated with diabetic renal disease. The aim of the present study was to examine whether these effects of castration can be attenuated with dihydrotestosterone (DHT) supplementation. The study was performed in castrated male Sprague-Dawley, streptozotocin-induced diabetic rats treated with 0 mg/day DHT (DHT0), 0.75 mg/day DHT (DHT0.75), or 2.0 mg/day DHT (DHT2.0) for 14 wk. Tre...

  2. Quantitative study of the myenteric plexus of the stomach of rats with streptozotocin-induced diabetes

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    Fregonesi Cristina Elena Prado Teles

    2001-01-01

    Full Text Available The purpose of the present study was to investigate the morphological and quantitative alterations of the myenteric plexus neurons of the stomach of rats with streptozotocin-induced chronic diabetes and compare them to those of non-diabetic animals. Samples from the body of the stomach were used for whole-mount preparations stained with NADH-diaphorase and for histological sections stained with hematoxylin-eosin. It was observed that diabetes cause a significant decrease on the number of neurons.

  3. Antidiabetic and Antioxidant Properties of Triticum aestivum in Streptozotocin-Induced Diabetic Rats

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    Yogesha Mohan

    2013-01-01

    Full Text Available The antidiabetic and antioxidant potential of Triticum aestivum were evaluated by using in vivo methods in normal and streptozotocin-induced diabetic rats. Diabetes was induced in the Wistar strain albino rats by injecting streptozotocin at a dose of 55 mg/kg body weight. Ethanolic extracts of Triticum aestivum at doses of 100 mg/kg body weight were administered orally for 30 days. Various parameters were studied and the treatment group with the extract showed a significant increase in the liver glycogen and a significant decrease in fasting blood glucose, glycosylated hemoglobin levels, and serum marker enzyme levels. The total cholesterol and serum triglycerides levels, low density lipoprotein, and very low density lipoprotein were also significantly reduced and the high density lipoprotein level was significantly increased upon treatment with the Triticum aestivum ethanol extract. A significant decrease in the levels of lipid peroxides, superoxide dismutase, and glutathione peroxidise and increase in the levels of vitamin E, catalase, and reduced glutathione were observed in Triticum aestivum treated diabetic rats. Thus, from this study we conclude that ethanolic extract of Triticum aestivum exhibited significant antihyperglycemic, hypolipidemic, and antioxidant activities in streptozotocin-induced diabetic rats.

  4. Portulaca oleracea L. alleviates liver injury in streptozotocin-induced diabetic mice

    Science.gov (United States)

    Peng, Hao; Gu, Wei; Li, Min; Chen, Zhe

    2018-01-01

    Purslane is a widespread succulent herb that exhibits various pharmacological effects. The purpose of this study was to evaluate the protective effect of Portulaca oleracea L. (purslane) on streptozotocin-induced diabetes in mice. Oral glucose-tolerance tests were carried out to assess blood glucose levels and body weight and food intake were recorded. The biochemical parameters anti-aspartate aminotransferase, alanine aminotransferase, insulin, triglycerides, total cholesterol, IL-6, IL-1β, and TNFα were also measured. The pathological condition of liver tissues were examined by hematoxylin–eosin staining. Rho, ROCK1, ROCK2, NFκBp65, p-NFκBp65, IκBα, and p-IκBα expression in liver tissue were analyzed by Western blot. Purslane increased body weight and decreased food intake. Purslane also significantly reduced concentrations of glucose, anti-aspartate aminotransferase, alanine aminotransferase, triglycerides, total cholesterol, IL-6, IL-1β, and TNFα in serum. Serum insulin was elevated with purslane treatment. In addition, pathologic liver changes in diabetic mice were also alleviated by purslane. Obtained data revealed that purslane restored the levels of Rho–NFκB signaling-related proteins in comparison with those of diabetic mice. Above all, it can be assumed that purslane might play a positive role in regulating streptozotocin-induced liver injury through suppressing the Rho–NFκB pathway. PMID:29343942

  5. Tracing Fasting Glucose Fluxes with Unstressed Catheter Approach in Streptozotocin Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Shichun Du

    2014-01-01

    Full Text Available Objective. Blood glucose concentrations of type 1 diabetic rats are vulnerable, especially to stress and trauma. The present study aimed to investigate the fasting endogenous glucose production and skeletal muscle glucose uptake of Streptozotocin induced type 1 diabetic rats using an unstressed vein and artery implantation of catheters at the tails of the rats as a platform. Research Design and Methods. Streptozotocin (65 mg·kg−1 was administered to induce type 1 diabetic state. The unstressed approach of catheters of vein and artery at the tails of the rats was established before the isotope tracer injection. Dynamic measurement of fasting endogenous glucose production was assessed by continuously infusing stable isotope [6, 6-2H2] glucose, while skeletal muscle glucose uptake by bolus injecting radioactively labeled [1-14C]-2-deoxy-glucose. Results. Streptozotocin induced type 1 diabetic rats displayed polydipsia, polyphagia, and polyuria along with overt hyperglycemia and hypoinsulinemia. They also had enhanced fasting endogenous glucose production and reduced glucose uptake in skeletal muscle compared to nondiabetic rats. Conclusions. The dual catheters implantation at the tails of the rats together with isotope tracers injection is a save time, unstressed, and feasible approach to explore the glucose metabolism in animal models in vivo.

  6. Maternal Rat Diabetes Mellitus Deleteriously Affects Insulin Sensitivity and Beta-Cell Function in the Offspring

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    Abdel-Baset M. Aref

    2013-01-01

    Full Text Available This study was designed to assess the effect of maternal diabetes in rats on serum glucose and insulin concentrations, insulin resistance, histological architecture of pancreas and glycogen content in liver of offspring. The pregnant rat females were allocated into two main groups: normal control group and streptozotocin-induced diabetic group. After birth, the surviving offspring were subjected to biochemical and histological examination immediately after delivery and at the end of the 1st and 2nd postnatal weeks. In comparison with the offspring of normal control dams, the fasting serum glucose level of offspring of diabetic mothers was significantly increased at the end of the 1st and 2nd postnatal weeks. Serum insulin level of offspring of diabetic dams was significantly higher at birth and decreased significantly during the following 2 postnatal weeks, while in normal rat offspring, it was significantly increased with progress of time. HOMA Insulin Resistance (HOMA-IR was significantly increased in the offspring of diabetic dams at birth and after 1 week than in normal rat offspring, while HOMA insulin sensitivity (HOMA-IS was significantly decreased. HOMA beta-cell function was significantly decreased at all-time intervals in offspring of diabetic dams. At birth, islets of Langerhans as well as beta cells in offspring of diabetic dams were hypertrophied. The cells constituting islets seemed to have a high division rate. However, beta-cells were degenerated during the following 2 post-natal weeks and smaller insulin secreting cells predominated. Vacuolation and necrosis of the islets of Langerhans were also observed throughout the experimental period. The carbohydrate content in liver of offspring of diabetic dams was at all-time intervals lower than that in control. The granule distribution was more random. Overall, the preexisting maternal diabetes leads to glucose intolerance, insulin resistance, and impaired insulin sensitivity and

  7. Effects of troxerutin on cognitive deficits and glutamate cysteine ligase subunits in the hippocampus of streptozotocin-induced type 1 diabetes mellitus rats.

    Science.gov (United States)

    Zhang, Songyun; Li, Hongyan; Zhang, Lihui; Li, Jie; Wang, Ruiying; Wang, Mian

    2017-02-15

    Increasing evidence demonstrates an association between diabetes and hippocampal neuron damage. This study aimed to determine the effects of troxerutin on cognitive deficits and glutamate cysteine ligase subunits (GCLM and GCLC) in the hippocampus of streptozotocin-induced type 1 diabetes mellitus (T1DM) rats. At 12weeks after streptozotocin injection, T1DM rats were randomly divided into 4 groups (n=15 each group) to receive no treatment (T1DM), saline (T1DM+saline), alpha-lipoic acid (T1DM+alpha-lipoic acid), and troxerutin (T1DM+troxerutin), respectively, for 6weeks. Meanwhile, 10 control animals (NC group) were assessed in parallel. Learning performance was evaluated by the Morris water maze. After treatment, hippocampi were collected for pathological examination by hematoxylin and eosin (H&E) staining. Next, hippocampal superoxide dismutase (SOD) activity, and malondialdehyde (MDA) and glutathione (GSH) levels were assessed. Finally, glutamate cysteine ligase catalytic (GCLC) and glutamate cysteine ligase modifier (GCLM) subunit mRNA and protein levels were quantified by reverse transcription polymerase chain reaction (RT-PCR) and Western blot, respectively. Compared with T1DM and T1DM+saline groups, escape latency was overtly reduced in T1DM+alpha-lipoic acid and T1DM+troxerutin groups. Significantly increased GCLM and GCLC mRNA levels, GCLC protein amounts, SOD activity, and GSH levels, and reduced MDA amounts were observed in T1DM+alpha-lipoic acid and T1DM+troxerutin groups. In T1DM and T1DM+saline groups, H&E staining showed less pyramidal cells in the hippocampus, with disorganized layers, karyopyknosis, decreased endochylema, and cavitation, effects relieved in T1DM+alpha-lipoic acid and T1DM+troxerutin groups. Troxerutin alleviates oxidative stress and promotes learning in streptozotocin-induced T1DM rats, a process involving GCLC expression. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. The protective effect of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes

    Science.gov (United States)

    Mohamed, Jamaludin; Shing, Saw Wuan; Md Idris, Muhd Hanis; Budin, Siti Balkis; Zainalabidin, Satirah

    2013-01-01

    OBJECTIVES: The aim of this study was to investigate the protective effects of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell (RBC) membrane oxidative stress in rats with streptozotocin-induced diabetes. METHODS: Forty male Sprague-Dawley rats weighing 230-250 g were randomly divided into four groups (n = 10 rats each): control group (N), roselle-treated control group, diabetic group, and roselle-treated diabetic group. Roselle was administered by force-feeding with aqueous extracts of roselle (100 mg/kg body weight) for 28 days. RESULTS: The results demonstrated that the malondialdehyde levels of the red blood cell membranes in the diabetic group were significantly higher than the levels in the roselle-treated control and roselle-treated diabetic groups. The protein carbonyl level was significantly higher in the roselle-treated diabetic group than in the roselle-treated control group but lower than that in the diabetic group. A significant increase in the red blood cell membrane superoxide dismutase enzyme was found in roselle-treated diabetic rats compared with roselle-treated control rats and diabetic rats. The total protein level of the red blood cell membrane, osmotic fragility, and red blood cell morphology were maintained. CONCLUSION: The present study demonstrates that aqueous extracts of roselle possess a protective effect against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes. These data suggest that roselle can be used as a natural antioxidative supplement in the prevention of oxidative damage in diabetic patients. PMID:24212844

  9. The protective effect of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2 against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes

    Directory of Open Access Journals (Sweden)

    Jamaludin Mohamed

    2013-10-01

    Full Text Available OBJECTIVES: The aim of this study was to investigate the protective effects of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2 against red blood cell (RBC membrane oxidative stress in rats with streptozotocin-induced diabetes. METHODS: Forty male Sprague-Dawley rats weighing 230-250 g were randomly divided into four groups (n = 10 rats each: control group (N, roselle-treated control group, diabetic group, and roselle-treated diabetic group. Roselle was administered by force-feeding with aqueous extracts of roselle (100 mg/kg body weight for 28 days. RESULTS: The results demonstrated that the malondialdehyde levels of the red blood cell membranes in the diabetic group were significantly higher than the levels in the roselle-treated control and roselle-treated diabetic groups. The protein carbonyl level was significantly higher in the roselle-treated diabetic group than in the roselle-treated control group but lower than that in the diabetic group. A significant increase in the red blood cell membrane superoxide dismutase enzyme was found in roselle-treated diabetic rats compared with roselle-treated control rats and diabetic rats. The total protein level of the red blood cell membrane, osmotic fragility, and red blood cell morphology were maintained. CONCLUSION: The present study demonstrates that aqueous extracts of roselle possess a protective effect against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes. These data suggest that roselle can be used as a natural antioxidative supplement in the prevention of oxidative damage in diabetic patients.

  10. The protective effect of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes.

    Science.gov (United States)

    Mohamed, Jamaludin; Shing, Saw Wuan; Idris, Muhd Hanis Md; Budin, Siti Balkis; Zainalabidin, Satirah

    2013-10-01

    The aim of this study was to investigate the protective effects of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell (RBC) membrane oxidative stress in rats with streptozotocin-induced diabetes. Forty male Sprague-Dawley rats weighing 230-250 g were randomly divided into four groups (n = 10 rats each): control group (N), roselle-treated control group, diabetic group, and roselle-treated diabetic group. Roselle was administered by force-feeding with aqueous extracts of roselle (100 mg/kg body weight) for 28 days. The results demonstrated that the malondialdehyde levels of the red blood cell membranes in the diabetic group were significantly higher than the levels in the roselle-treated control and roselle-treated diabetic groups. The protein carbonyl level was significantly higher in the roselle-treated diabetic group than in the roselle-treated control group but lower than that in the diabetic group. A significant increase in the red blood cell membrane superoxide dismutase enzyme was found in roselle-treated diabetic rats compared with roselle-treated control rats and diabetic rats. The total protein level of the red blood cell membrane, osmotic fragility, and red blood cell morphology were maintained. The present study demonstrates that aqueous extracts of roselle possess a protective effect against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes. These data suggest that roselle can be used as a natural antioxidative supplement in the prevention of oxidative damage in diabetic patients.

  11. Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

    DEFF Research Database (Denmark)

    Martens, Geert A; Jiang, Lei; Hellemans, Karine H

    2011-01-01

    The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser capture...

  12. Streptozotocin-induced diabetes mellitus in spontaneously hypertensive rats: a pathophysiological model for the combined effects of hypertension and diabetes

    NARCIS (Netherlands)

    Pijl, A. J.; van der Wal, A. C.; Mathy, M. J.; Kam, K. L.; Hendriks, M. G.; Pfaffendorf, M.; van Zwieten, P. A.

    1994-01-01

    The present study was undertaken to investigate the combined effects of hypertension and streptozotocin-induced diabetes mellitus in the rat. Accordingly, four groups of rats were studied: Wistar Kyoto rats (WKY), diabetic WKY, spontaneously hypertensive rats (SHR) and diabetic SHR, respectively.

  13. Hypoglycemic and hypocholesterolemic activities of the aqueous preparation of Kalanchoe pinnata leaves in streptozotocin-induced diabetic rats

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    Nikhil Menon

    2015-01-01

    Conclusions: The observed decrease in body weight, blood glucose and cholesterol level suggests that the aqueous K. pinnata preparation consumption may be beneficial in the management of diabetes mellitus. The observed adverse effect on alkaline phosphatase activity may be due to the combined effect of streptozotocin-induced diabetes and K. pinnata preparation administration.

  14. Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

    DEFF Research Database (Denmark)

    Martens, Geert A; Jiang, Lei; Hellemans, Karine H

    2011-01-01

    The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser capture...... microdissected beta cells, monitor adaptations of the beta cell phenotype to fasting, and retrieve possible conserved transcriptional regulators....

  15. Capparis spinosa L. aqueous extract evokes antidiabetic effect in streptozotocin-induced diabetic mice

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    Mohamed Eddouks

    2017-02-01

    Full Text Available Objective: As the aqueous extract of Capparis spinosa (CS possess antidiabetic effect, he present study aims to reveal the possible  mechanism of action of CS in diabetic mice.Materials and Methods: Both single and repeated oral administrations of aqueous extract of CS were performed in multi-low dose streptozotocin-induced (MLDS diabetic mice. Euglycemic hyperinsulinemic clamp was used in association with the endogenous glucose production (perfusion rate of 3-3H glucose to evaluate the effect of CS aqueous extract on insulin sensitivity.Results: Our study showed that aqueous extract of CS possess a potent hypoglycaemic activity in MLDS diabetic mice. Furthermore, the analysis perfusion of 3-3H glucose demonstrated  the parallel decrease of basal endogenous glucose production (EGP with the hypoglycaemic activity. EGP was lower in CS-Treated group when compared to the control group (p

  16. Portulaca oleracea L. alleviates liver injury in streptozotocin-induced diabetic mice

    Directory of Open Access Journals (Sweden)

    Zheng G

    2017-12-01

    Full Text Available Guoyin Zheng,1,* Fengfeng Mo,2,* Chen Ling,3,* Hao Peng,1 Wei Gu,1 Min Li,2 Zhe Chen1 1Department of Traditional Chinese Medicine, Changhai Hospital, 2Department of Military Hygiene, Second Military Medical University, 3Department of Biology, School of Life Science, Fudan University, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: Purslane is a widespread succulent herb that exhibits various pharmacological effects. The purpose of this study was to evaluate the protective effect of Portulaca oleracea L. (purslane on streptozotocin-induced diabetes in mice. Oral glucose-tolerance tests were carried out to assess blood glucose levels and body weight and food intake were recorded. The biochemical parameters anti-aspartate aminotransferase, alanine aminotransferase, insulin, triglycerides, total cholesterol, IL-6, IL-1β, and TNFα were also measured. The pathological condition of liver tissues were examined by hematoxylin–eosin staining. Rho, ROCK1, ROCK2, NFκBp65, p-NFκBp65, IκBα, and p-IκBα expression in liver tissue were analyzed by Western blot. Purslane increased body weight and decreased food intake. Purslane also significantly reduced concentrations of glucose, anti-aspartate aminotransferase, alanine ­aminotransferase, triglycerides, total cholesterol, IL-6, IL-1β, and TNFα in serum. Serum insulin was elevated with purslane treatment. In addition, pathologic liver changes in diabetic mice were also alleviated by purslane. Obtained data revealed that purslane restored the levels of Rho–NFκB signaling-related proteins in comparison with those of diabetic mice. Above all, it can be assumed that purslane might play a positive role in regulating streptozotocin-induced liver injury through suppressing the Rho–NFκB pathway. Keywords: Portulaca oleracea L., diabetes, liver injury, Rho–NFκB

  17. Beta cell proliferation and growth factors

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis; Svensson, C; Møldrup, Annette

    1999-01-01

    Formation of new beta cells can take place by two pathways: replication of already differentiated beta cells or neogenesis from putative islet stem cells. Under physiological conditions both processes are most pronounced during the fetal and neonatal development of the pancreas. In adulthood little...... increase in the beta cell number seems to occur. In pregnancy, however, a marked hyperplasia of the beta cells is observed both in rodents and man. Increased mitotic activity has been seen both in vivo and in vitro in islets exposed to placental lactogen (PL), prolactin (PRL) and growth hormone (GH...... and activation of the tyrosine kinase JAK2 and the transcription factors STAT1 and 3. The activation of the insulin gene however also requires the distal part of the receptor and activation of calcium uptake and STAT5. In order to identify putative autocrine growth factors or targets for growth factors we have...

  18. Curcumin and turmeric delay streptozotocin-induced diabetic cataract in rats.

    Science.gov (United States)

    Suryanarayana, Palla; Saraswat, Megha; Mrudula, Tiruvalluru; Krishna, T Prasanna; Krishnaswamy, Kamala; Reddy, G Bhanuprakash

    2005-06-01

    The purpose of this study was to investigate the effect of curcumin and its source, turmeric, on streptozotocin-induced diabetic cataract in rats. Wistar-NIN rats were selected and diabetes was induced by streptozotocin (35 mg/kg body weight, intraperitoneally) and divided into four groups (group II-V). The control (group I) rats received only vehicle. Group I and II animals received an unsupplemented AIN-93 diet, and those in groups III, IV, and V received 0.002% and 0.01% curcumin and 0.5% turmeric, respectively, in an AIN-93 diet for a period of 8 weeks. Cataract progression due to hyperglycemia was monitored by slit lamp biomicroscope and classified into four stages. At the end of 8 weeks, the animals were killed and the biochemical pathways involved in the pathogenesis of cataract such as oxidative stress, polyol pathway, alterations in protein content and crystallin profile in the lens were investigated, to understand the possible mechanism of action of curcumin and turmeric. Blood glucose and insulin levels were also determined. Although, both curcumin and turmeric did not prevent streptozotocin-induced hyperglycemia, as assessed by blood glucose and insulin levels, slit lamp microscope observations indicated that these supplements delayed the progression and maturation of cataract. The present studies suggest that curcumin and turmeric treatment appear to have countered the hyperglycemia-induced oxidative stress, because there was a reversal of changes with respect to lipid peroxidation, reduced glutathione, protein carbonyl content and activities of antioxidant enzymes in a significant manner. Also, treatment with turmeric or curcumin appears to have minimized osmotic stress, as assessed by polyol pathway enzymes. Most important, aggregation and insolubilization of lens proteins due to hyperglycemia was prevented by turmeric and curcumin. Turmeric was more effective than its corresponding levels of curcumin. The results indicate that turmeric and curcumin

  19. Study of Hypoglycemic Activity of Aqueous Extract of Leucas indica Linn. Aerial Parts on Streptozotocin Induced Diabetic Rats

    OpenAIRE

    Mahananda Sarkar; Prova Biswas; Amalesh Samanta

    2013-01-01

    The present study was designed to evaluate the hypoglycemic activity of the aqueous extract of Leucas indica Linn. on streptozotocin induced diabetic rats. The extract showed a significant dose depended (200 and 400 mg/kg b.w, orally) reduction in fasting blood glucose level, comparing with reference drug, glibenclamide (0.5 mg/kg b.w, orally). In addition, the changes in body weight, analysis of serum biochemical parameters like lipid profile, glutamate oxaloacetate transaminase, glutamate p...

  20. Effect of Vaccinium bracteatum Thunb. leaves extract on blood glucose and plasma lipid levels in streptozotocin-induced diabetic mice.

    Science.gov (United States)

    Wang, Li; Zhang, Xue Tong; Zhang, Hai Yan; Yao, Hui Yuan; Zhang, Hui

    2010-08-09

    To investigate the hypoglycemic effects of Vaccinium bracteatum Thunb. leaves (VBTL) extract in streptozotocin-induced diabetic mice. After administration of VBTL extract for 4 weeks, the body weight, organ weight, blood glucose (BG), insulin and plasma lipid levels of streptozotocin-induced diabetic mice were measured. Body weights of diabetic mice treated with VBTL extract were partly recovered. The BG levels of AEG (diabetic mice treated with VBTL aqueous extract) were reduced to 91.52 and 85.82% at week 2 and week 4, respectively (P0.05). The insulin levels of AEG and EEG were obviously higher (P<0.05) than those of MC (diabetic mice in model control group). Comparing with MC, AEG and EEG had significantly lower (P<0.05) TC or TG levels and similar HDL-cholesterol or LDL-cholesterol levels. In comparison with non-diabetic control mice, AEG had similar plasma lipid levels except higher LDL-cholesterol level, while EEG had higher TC, TG and LDL-cholesterol levels and lower HDL-cholesterol levels. Both aqueous and ethanolic extract of VBTL possess a potential hypoglycemic effect in streptozotocin-induced diabetic mice. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  1. Toxicological and safety evaluation of Nigella sativa lipid and volatile fractions in streptozotocin induced diabetes mellitus

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    Muhammad Tauseef Sultan

    2014-09-01

    Full Text Available Objective: To evaluate the toxicological aspects of Nigella sativa (N. sativa lipid and volatile fractions in streptozotocin induced diabetes mellitus. Methods: National Institute of Health (NIH, Islamabad provided us thirty Sprague Dawley rats that were further divided into three groups, i.e. control, N. sativa lipid fraction (4% and N. sativa volatile fraction (0.3%, respectively. The serological and haematological indices were evaluated at 4-week intervals during 56 d study. Results: The results indicated that the diabetes mellitus imparted negative effects on various serological and haematological attributes. However, supplementation of the N. sativa lipid fraction and N. sativa volatile fraction ameliorated the adverse consequences of diabetes mellitus. The diabetes induced renal toxicity and imbalanced serum chemistry were slightly modulated by experimental diets. However, the impact of essential oil was more significant as compared to the fixed oil. Conclusions: In a nutshell, experimental diets containing N. sativa lipid fraction and N. sativa volatile fraction are effective without having any toxicological effects, and experimental diets reduced toxicological and adverse consequences of diabetes mellitus.

  2. The effects of chronic resveratrol treatment on vascular responsiveness of streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Silan, Coskun

    2008-05-01

    Deficiency in the vasorelaxant capacity is a result of an oxidative stress in diabetic animals and seems to be an etiological factor of vascular complications of diabetes. The present study was designed to examine whether resveratrol (RSV), a polyphenolic compound which is naturally present in grape and red wine, has a protective effect on diabetic aorta. Resveratrol (5 mg/kg/d, i.p.) was administered for 42 d to streptozotocin (STZ) (60 mg/kg) induced diabetic rats. Loss of weight, hyperglycemia, and elevated levels of plasma malondialdehyde (MDA) were observed in diabetic rats. Resveratrol treatment was significantly effective for these metabolic and biochemical abnormalities. The contractile responses of the aorta were recorded. Compared with control subjects, the aorta showed significantly enhanced contractile responses to noradrenaline (NA), but not to potassium chloride (KCl), in diabetic rats. Treatment of diabetic rats with resveratrol significantly reversed the increases in responsiveness and sensitivity of aorta to noradrenaline. In diabetic aorta, the relaxation response to acetylcholine (Ach) was found to be significantly decreased compared with control subjects, and resveratrol treatment reversed this; no such change was observed in the relaxation response to sodium nitroprusside (SNP). These results indicated that resveratrol significantly improved not only glucose metabolism and oxidative injury but also impaired vascular responses in streptozotocin induced diabetic rats.

  3. Effect of Bauhinia holophylla treatment in Streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Pinheiro, Marcelo S; Rodrigues, Luhara S; S, Leila; Moraes-Souza, Rafaianne Q; Soares, Thaigra S; Américo, Madileine F; Campos, Kleber E; Damasceno, Débora C; Volpato, Gustavo T

    2017-01-01

    Bauhinia holophylla, commonly known as "cow's hoof", is widely used in Brazilian folk medicine for the diabetes treatment. Therefore, the aim of this study was at evaluating the aqueous extract effect of Bauhinia holophylla leaves treatment on the streptozotocin-induced diabetic rats. Diabetes was induced by Streptozotocin (40 mg/Kg) in female Wistar rats. Oral administration of aqueous extract of Bauhinia holophylla leaves was given to non-diabetic and diabetic rats at a dose of 400 mg/kg during 21 days. On day 17 of treatment, the Oral Glucose Tolerance Test was performed to determine the area under the curve. At the end of the treatment, the animals were anesthetized and blood was collected for serum biochemical parameters analysis. After treatment with Bauhinia holophylla extract, non-diabetic and diabetic rats presented no glycemic changes. On the other hand, the plant treatment decreased body weight and increased ALT and AST activities. In conclusion, the treatment with aqueous extract of B. holophylla leaves given to diabetic rats presented no hypoglycemic effect in nondiabetic animals and no antidiabetic effect in diabetic animals with the doses studied. In addition, the diabetic animals treated with the B. holophylla extract showed inconvenient effects and its indiscriminate consumption requires particular carefulness.

  4. Eriodictyol prevents early retinal and plasma abnormalities in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Bucolo, Claudio; Leggio, Gian Marco; Drago, Filippo; Salomone, Salvatore

    2012-07-01

    Diabetic retinopathy is a complex disease that has potential involvement of inflammatory and oxidative stress-related pathways in its pathogenesis. We hypothesized that eriodictyol, one of the most abundant dietary flavonoids, could be effective against diabetic retinopathy, which involves significant oxidative stress and inflammation. The aim of the present study was to investigate the effects of eriodictyol in early retinal and plasma changes of streptozotocin-induced diabetic rats. The effect of eriodictyol treatment (0.1, 1, 10 mg/kg daily for 10 days) was evaluated by TNF-α, ICAM-1, VEGF, and eNOS protein levels measurement in the retina, plasma lipid peroxidation, and blood-retinal barrier (BRB) integrity. Increased amounts of cytokines, adhesion molecule, and nitric oxide synthase were observed in retina from diabetic rats. Eriodictyol treatment significantly lowered retinal TNF-α, ICAM-1, VEGF, and eNOS in a dose-dependent manner. Further, treatment with eriodictyol significantly suppressed diabetes-related lipid peroxidation, as well as the BRB breakdown. These data demonstrated that eriodictyol attenuates the degree of retinal inflammation and plasma lipid peroxidation preserving the BRB in early diabetic rats. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Effect of irradiation on the dental pulp tissues in streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Kang, Ho Duk; Hwang, Eui Hwan; Lee, Sang Rae

    2005-01-01

    To observe the histological changes in the pulp tissues of mandibular molars in streptozotocin-induced diabetic rats after irradiation. The male Sprague-Dawley rats weighing approximately 250 gm were divided into four groups : control, diabetes, irradiation, and diabetes-irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in control and irradiation groups were injected with citrate buffer only. After 5 days, the head and neck region of the rats in irradiation and diabetes-irradiation groups were irradiated with a single absorbed dose of 10 Gy. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the mandibular molars were sectioned and observed using a histopathological method. In the diabetes group, capillary dilatation was observed. However, there was no obvious morphologic alteration of the odontoblasts. In the irradiation group, generalized necrosis of the dental pulp tissues was observed. Vacuolation of the odontoblasts and dilatation of the capillaries were noted in the early experimental phases. In the diabetes-irradiation group, generalized degeneration of the dental pulp tissues was observed. Vacuolation of the dental pulp cells and the odontoblasts was noted in the late experimental phases. This experiment suggest that dilatation of the capillaries in the dental pulp tissue is induced by diabetic state, and generalized degeneration of the dental pulp tissues is induced by irradiation of the diabetic group.

  6. Crocin Improved Learning and Memory Impairments in Streptozotocin-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Esmaeal Tamaddonfard

    2013-01-01

    Full Text Available Objective(s: Crocin influences many biological functions including memory and learning. The present study was aimed to investigate the effects of crocin on learning and memory impairments in streptozotocine-induced diabetic rats. Materials and Methods: Diabetes was induced by intraperitoneal (IP injection of streptozotocin (STZ, 45 mg/kg. Transfer latency (TL paradigm in elevated plus-maze (EPM was used as an index of learning and memory. Plasma levels of total antioxidant capacity (TAC and malondialdehyde (MDA, blood levels of glucose, and serum concentrations of insulin were measured. The number of hippocampal neurons was also counted. Results: STZ increased acquisition transfer latency (TL1 and retention transfer latency (TL2, and MDA, decreased transfer latency shortening (TLs and TCA, produced hyperglycemia and hypoinsulinemia, and reduced the number of neurons in the hippocampus. Learning and memory impairments and blood TCA, MDA, glucose, and insulin changes induced by streptozotocin were improved with long-term IP injection of crocin at doses of 15 and 30 mg/kg. Crocin prevented hippocampal neurons number loss in diabetic rats. Conclusion: The results indicate that oxidative stress, hyperglycemia, hypoinsulinemia, and reduction of hippocampal neurons may be involved in learning and memory impairments in STZ-induced diabetic rats. Antioxidant, antihyperglycemic, antihypoinsulinemic, and neuroprotective activities of crocin might be involved in improving learning and memory impairments.

  7. Antidiabetic activity of traditional Indian gold containing preparation: Shadguna Balijarita Makaradhwaja on streptozotocin induced diabetic rats.

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    Sanjay Khedekar

    2016-06-01

    Full Text Available Background: Makaradhwaja a gold containing mercurial preparation used for diabetes mellitus in indigenous system of medicine. It is a popular aphrodisiac and rejuvenator traditional medicine. It is prepared by using processed gold, mercury and sulfur in different ratios by applying intermittent heating pattern in Valuka Yantra. Objectives: The aim of study was to evaluate anti-diabetic effect of Shadguna Balijarita Makaradhwaja on Streptozotocin induced diabetic rats. Methods: Diabetes was induced to normal rats by injecting Streptozotocin in dose 40 mg/kg. Powdered Shadguna Balijarita Makaradhwaja and dried extract of Tinospora cordifolia were mixed with honey and administered orally for 20 days at dose 2.63 mg/kg and 42.34 mg/kg body weight respectively. The effects of treatment on body weight changes and blood glucose levels were quantified on Day 1, 5, 10, 15 and 21 of the experiments. On 21st day animals were sacrificed and gross histopathological changes in liver, kidney and pancreas were illustrated. Blood sugar level, Glyacated hemoglobin, blood urea, serum cholesterol, serum creatinine, serum triglyceride, and serum protein were estimated with standard methods. Study was conducted in the year 2011. Results: Test drug observed significant decrease (P [J Complement Med Res 2016; 5(2.000: 162-167

  8. Hypolipidemic action of curcumin, the active principle of turmeric (Curcuma longa) in streptozotocin induced diabetic rats.

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    Babu, P S; Srinivasan, K

    1997-01-01

    Streptozotocin-induced diabetic rats were maintained on 0.5% curcumin containing diet for 8 weeks. Blood cholesterol was lowered significantly by dietary curcumin in these diabetic animals. Cholesterol decrease was exclusively from LDL-VLDL fraction. Significant decrease in blood triglyceride and phospholipids was also brought about by dietary curcumin in diabetic rats. In a parallel study, wherein diabetic animals were maintained on a high cholesterol diet, the extents of hypercholesterolemia and phospholipidemia were still higher compared to those maintained on control diet. Curcumin exhibited lowering of cholesterol and phospholipid in these animals also. Liver cholesterol, triglyceride and phospholipid contents were elevated under diabetic conditions. Dietary curcumin showed a distinct tendency to counter these changes in lipid fractions of liver. This effect of curcumin was also seen in diabetic animals maintained on high cholesterol diet. Dietary curcumin also showed significant countering of renal cholesterol and triglycerides elevated in diabetic rats. In order to understand the mechanism of hypocholesterolemic action of dietary curcumin, activities of hepatic cholesterol-7a-hydroxylase and HMG CoA reductase were measured. Hepatic cholesterol-7a-hydroxylase activity was markedly higher in curcumin fed diabetic animals suggesting a higher rate of cholesterol catabolism.

  9. Effect of bitter gourd and spent turmeric on glycoconjugate metabolism in streptozotocin-induced diabetic rats.

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    Vijayalakshmi, B; Kumar, G Suresh; Salimath, P V

    2009-01-01

    Changes in glycoconjugate metabolism during the development of diabetic complications and their modulation by feeding bitter gourd and spent turmeric as fiber-rich source. This was studied by measuring the contents of total sugar, uronic acid, amino sugar, and sulfate in the streptozotocin-induced diabetic rats. Total sugar content decreased in liver, spleen, and brain, while an increase was observed in heart and lungs. Uronic acid content in liver, spleen, and brain decreased, and marginal increase was observed in testis. Amino sugar content decreased in liver, spleen, lungs and heart during diabetes, and augmentation was observed to different extents. Decrease in sulfation of glycoconjugates was observed in liver, spleen, lungs and heart during diabetes and was significantly ameliorated by bitter gourd and spent turmeric, except brain. Protein content decreased in liver, while an increase was observed in brain. The studies clearly showed alteration in glycoconjugate metabolism during diabetes and amelioration to different extents by feeding bitter gourd and spent turmeric. Improvement is due to slow release of glucose by fiber in the gastrointestinal track and short-chain fatty acid production from fiber by colon microbes.

  10. Effects of caffeine on locomotor activity in streptozotocin-induced diabetic rats.

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    Bădescu, S V; Tătaru, C P; Kobylinska, L; Georgescu, E L; Zahiu, D M; Zăgrean, A M; Zăgrean, L

    2016-01-01

    Diabetes mellitus modifies the expression of adenosine receptors in the brain. Caffeine acts as an antagonist of A1 and A2A adenosine receptors and was shown to have a dose-dependent biphasic effect on locomotion in mice. The present study investigated the link between diabetes and locomotor activity in an animal model of streptozotocin-induced diabetes, and the effects of a low-medium dose of caffeine in this relation. The locomotor activity was investigated by using Open Field Test at 6 weeks after diabetes induction and after 2 more weeks of chronic caffeine administration. Diabetes decreased locomotor activity (total distance moved and mobility time). Chronic caffeine exposure impaired the locomotor activity in control rats, but not in diabetic rats. Our data suggested that the medium doses of caffeine might block the A2A receptors, shown to have an increased density in the brain of diabetic rats, and improve or at least maintain the locomotor activity, offering a neuroprotective support in diabetic rats. Abbreviations : STZ = streptozotocin, OFT = Open Field Test.

  11. Renoprotective effect of lansoprazole in streptozotocin-induced diabetic nephropathy in wistar rats.

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    Kaur, Rupinder; Sodhi, Rupinder Kaur; Aggarwal, Neha; Kaur, Jaspreet; Jain, Upendra K

    2016-01-01

    Proton pump inhibitors (PPIs) have exhibited glucose lowering action in animal models of diabetes; however, their potential in diabetes-related complications has not yet been evaluated. Hence, the present study has been undertaken to investigate the renoprotective potential of lansoprazole in streptozotocin-induced diabetic nephropathy in wistar rats. Diabetic nephropathy was induced with a single injection of streptozotocin (STZ, 45 mg/kg, i.p.). Lansoprazole (40 mg/kg; 80 mg/kg, p.o.; 4 weeks) was administered to diabetic rats after 4 weeks of STZ treatment. A battery of biochemical tests such as serum glucose, glycated hemoglobin, blood urea nitrogen (BUN), serum creatinine, albumin, and kidney weight/body weight (%) ratio were performed to evaluate the renal functions. Oxidative stress was determined by estimating renal thiobarbituric acid reactive species (TBARS) and reduced glutathione (GSH) levels. Lipid profile was assessed by determining serum cholesterol (TC), triglyceride (TG), and high-density lipoprotein (HDL). The STZ-treated rats demonstrated deleterious alterations in kidney functions, enhanced oxidative stress, and disturbed lipid profile. Administration of lansoprazole to diabetic rats significantly reduced serum glucose, glycated hemoglobin, BUN, creatinine, albumin levels, and oxidative stress. Serum lipids like TC and TG were decreased, and HDL was enhanced in lansoprazole-treated STZ rats. The findings of our study indicate that renoprotective effects of lansoprazole may be attributed to its glucose-lowering, lipid-lowering, and antioxidative potential.

  12. Antidiabetic effect of Chloroxylon swietenia bark extracts on streptozotocin induced diabetic rats

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    B. Jayaprasad

    2016-03-01

    Full Text Available Diabetes has been increasing at an alarming rate around the world, and experts have relied on remedies from the utilization of ancient drugs that are essentially derived from plants. The present study aimed to evaluate the antidiabetic potential of Chloroxylon swietenia bark extracts on streptozotocin induced diabetic rats. Diabetes was induced in male albino Wistar rats by single intraperitoneal injection of streptozotocin (STZ (50 mg/kg b.w.. The diabetic rats were administered orally with C. swietenia bark (CSB methanolic (CSBMEt and aqueous (CSBAEt (250 mg/kg b.w. extracts and glibenclamide (600 µg/kg b.w. by intragastric intubation for 45 days. The result showed a heavy loss in weight, increase in blood glucose and glycosylated hemoglobin level, and decline in plasma insulin and total hemoglobin content. Furthermore, glucose-6-phosphatase and fructose-1,6-bis phosphatase were found to be increased whereas hexokinase and glycogen contents were decreased in STZ induced diabetic rats. CSBAEt, CSBMEt and glibenclamide treated diabetic rats showed moderate reduction in blood glucose and glycosylated hemoglobin levels; in addition, plasma insulin and hemoglobin levels were elevated. The altered activities of carbohydrate metabolizing enzymes and liver glycogen were improved remarkably. CSBMEt results were comparable to the standard drug glibenclamide. The present findings support the usage of the plant extracts for the traditional treatment of diabetes.

  13. The role of oxidative stress in streptozotocin-induced diabetic nephropathy in rats.

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    Fernandes, Sheila Marques; Cordeiro, Priscilla Mendes; Watanabe, Mirian; Fonseca, Cassiane Dezoti da; Vattimo, Maria de Fatima Fernandes

    2016-10-01

    The objective of this study was to evaluate the role of oxidative stress in an experimental model of streptozotocin-induced diabetic nephropathy in rats. Wistar, adult, male rats were used in the study. Animals were divided in the following groups: Citrate (control, citrate buffer 0.01M, pH 4.2 was administrated intravenously - i.v - in the caudal vein), Uninephrectomy+Citrate (left uninephrectomy-20 days before the study), DM (streptozotocin, 65 mg/kg, i.v, on the 20th day of the study), Uninephrectomy+DM. Physiological parameters (water and food intake, body weight, blood glucose, kidney weight, and relative kidney weight); renal function (creatinine clearance), urine albumin (immunodiffusion method); oxidative metabolites (urinary peroxides, thiobarbituric acid reactive substances, and thiols in renal tissue), and kidney histology were evaluated. Polyphagia, polydipsia, hyperglycemia, and reduced body weight were observed in diabetic rats. Renal function was reduced in diabetic groups (creatinine clearance, p < 0.05). Uninephrectomy potentiated urine albumin and increased kidney weight and relative kidney weight in diabetic animals (p < 0.05). Urinary peroxides and thiobarbituric acid reactive substances were increased, and the reduction in thiol levels demonstrated endogenous substrate consumption in diabetic groups (p < 0.05). The histological analysis revealed moderate lesions of diabetic nephropathy. This study confirms lipid peroxidation and intense consumption of the antioxidant defense system in diabetic rats. The association of hyperglycemia and uninephrectomy resulted in additional renal injury, demonstrating that the model is adequate for the study of diabetic nephropathy.

  14. Cardio-protective effects of carnitine in streptozotocin-induced diabetic rats

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    Malone Michael A

    2006-01-01

    Full Text Available Abstract Background Streptozotocin-induced diabetes (STZ-D in rats has been associated with carnitine deficiency, bradycardia and left ventricular enlargement. Aim The purpose of this study was to determine whether oral carnitine supplementation would normalize carnitine levels and cardiac function in STZ-D rats. Methods Wistar rats (48 were made hyperglycemic by STZ at 26 weeks of age. Same age normal Wistar rats (24 were used for comparison. Echocardiograms were performed at baseline 2, 6, 10, and 18 weeks after STZ administration in all animals. HbA1c, serum carnitine and free fatty acids (FFA were measured at the same times. Since STZ-D rats become carnitine deficient, 15 STZ-D rats received supplemental oral carnitine for 16 weeks. Results The heart rates for the STZ-D rats (290 ± 19 bpm were less than control rats (324 ± 20 bpm (p Conclusion Thus, supplemental oral carnitine in STZ-D rats normalized serum carnitine, heart rate regulation and left ventricular size. These findings suggest a metabolic mechanism for the cardiac dysfunction noted in this diabetic animal model.

  15. Effect of melatonin on serum glucose and body weights in streptozotocin induced diabetes in albino rats

    International Nuclear Information System (INIS)

    Hidayat, M.

    2015-01-01

    It has been demonstrated in experimental animal models that oxidative stress causes persistent and chronic hyperglycaemia, causing reduction in antioxidant defence system, ultimately leading to accumulation of free radicals.This study was performed to observe the effect of melatonin on serum glucose and body weights in streptozotocin induced diabetes in albino rats. Methods: Forty healthy adult male albino rats were included in the study and divided equally into 4 groups for 6 weeks. Group-A was taken as control. Group-B received streptozotocin I/P in a dose of 37 mg/kg body weight. Group-C received 10 mg/100 ml melatonin in drinking water and Group-D received only melatonin. Results: Streptozotocin significantly increased serum glucose and decreased weight in group B animals, whereas in group C, melatonin significantly restored serum glucose but could not restore the body weights reduced by streptozotocin. There was a significant reduction in body weight in melatonin treated group D animals. Conclusion: Melatonin decreases oxidative stress and hyperglycemia, but cannot restore the body weight reduced by streptozotocin. In fact, it further reduces body weight both in diabetic and normal state. (author)

  16. Effect of opium on glucose metabolism and lipid profiles in rats with streptozotocin-induced diabetes.

    Science.gov (United States)

    Sadeghian, Saeed; Boroumand, Mohammad Ali; Sotoudeh-Anvari, Maryam; Rabbani, Shahram; Sheikhfathollahi, Mahmood; Abbasi, Ali

    2009-01-01

    This experimental study was performed to determine the impact of opium use on serum lipid profile and glucose metabolism in rats with streptozotocin-induced diabetes. To determine the effect of opium, 20 male rats were divided into control (n = 10) and opium-treated (n = 10) groups. After diabetes induction, the animals were investigated for daily glucose measurements for 35 days. Serum lipid profile and haemoglobin A1c (HbA(1c)) were assayed at the baseline (before induction of diabetes) and at 35-day follow-up. The glycaemia levels in the rats treated with opium were similar to the levels measured in the control rats (544.8 +/- 62.2 mg/dl v. 524.6 +/- 50.0 mg/dl, P = 0.434). In addition, there was no difference between the opium-treated rats and control rats in HbA(1c) (6.5 +/- 0.5% v. 6.6 +/- 0.2%, P = 0.714). Compared to the control rats, the serum total cholesterol, high density lipoprotein (HDL), triglyceride and lipoprotein (a) in the test animals were similar. Opium use has no significant effect on glucose metabolism and serum lipid profile in rats with induced diabetes.

  17. Assessment of diabetic peripheral neuropathy in streptozotocin-induced diabetic rats with magnetic resonance imaging

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    Wang, Dongye; Zhang, Xiang; Lu, Liejing; Li, Haojiang; Zhang, Fang; Chen, Yueyao; Shen, Jun [Sun Yat-Sen University, Department of Radiology, Sun Yat-Sen Memorial Hospital, Guangzhou, Guangdong (China)

    2014-09-10

    To determine the role of magnetic resonance (MR) imaging and quantitative T2 value measurements in the assessment of diabetic peripheral neuropathy (DPN). Sequential MR imaging, T2 measurement, and quantitative sensory testing of sciatic nerves were performed in streptozotocin-induced diabetic rats (n = 6) and normal control rats (n = 6) over a 7-week follow-up period. Histological assessment was obtained from 48 diabetic rats and 48 control rats once weekly for 7 weeks (n = 6 for each group at each time point). Nerve signal abnormalities were observed, and the T2 values, mechanical withdrawal threshold (MWT), and histological changes were measured and compared between diabetic and control animals. Sciatic nerves in the diabetic rats showed a gradual increase in T2 values beginning at 2 weeks after the induction (P = 0.014), while a decrease in MWT started at 3 weeks after the induction (P = 0.001). Nerve T2 values had a similar time course to sensory functional deficit in diabetic rats. Histologically, sciatic nerves of diabetic rats demonstrated obvious endoneural oedema from 2 to 3 weeks after the induction, followed by progressive axonal degeneration, Schwann cell proliferation, and coexistent disarranged nerve regeneration. Nerve T2 measurement is potentially useful in detecting and monitoring diabetic neuropathy. (orig.)

  18. Assessment of diabetic peripheral neuropathy in streptozotocin-induced diabetic rats with magnetic resonance imaging

    International Nuclear Information System (INIS)

    Wang, Dongye; Zhang, Xiang; Lu, Liejing; Li, Haojiang; Zhang, Fang; Chen, Yueyao; Shen, Jun

    2015-01-01

    To determine the role of magnetic resonance (MR) imaging and quantitative T2 value measurements in the assessment of diabetic peripheral neuropathy (DPN). Sequential MR imaging, T2 measurement, and quantitative sensory testing of sciatic nerves were performed in streptozotocin-induced diabetic rats (n = 6) and normal control rats (n = 6) over a 7-week follow-up period. Histological assessment was obtained from 48 diabetic rats and 48 control rats once weekly for 7 weeks (n = 6 for each group at each time point). Nerve signal abnormalities were observed, and the T2 values, mechanical withdrawal threshold (MWT), and histological changes were measured and compared between diabetic and control animals. Sciatic nerves in the diabetic rats showed a gradual increase in T2 values beginning at 2 weeks after the induction (P = 0.014), while a decrease in MWT started at 3 weeks after the induction (P = 0.001). Nerve T2 values had a similar time course to sensory functional deficit in diabetic rats. Histologically, sciatic nerves of diabetic rats demonstrated obvious endoneural oedema from 2 to 3 weeks after the induction, followed by progressive axonal degeneration, Schwann cell proliferation, and coexistent disarranged nerve regeneration. Nerve T2 measurement is potentially useful in detecting and monitoring diabetic neuropathy. (orig.)

  19. Some positive effects of pine oil on brain tissue in streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Demir, E.; Keser, S.; Yilmiz, O.

    2016-01-01

    Pine oil has antiseptic, expectorant and antioxidant properties and has been used for treatment of rheumatism, respiratory and urinary system and skin diseases. We aimed to determine protective effects of pine oil (PO) on the lipid-soluble vitamins, cholesterol, GSH, total protein, MDA, fatty acid levels of brain tissue of the streptozotocin-induced diabetic rats. Rats were randomly divided into three groups: Control (C), streptozotocin (STZ), streptozotocin+pine oil (PO) groups. Streptozotocin was injected intraperitoneally single dose (65 mg/kg) to the STZ and PO groups for inducing of diabetes. To the PO group 1 mg/kg dose pine oil was intraperitoneally injected every next day. While the GSH and total protein were significantly decreased in the Streptozotocin (STZ) group, their levels were protected in PO group. MDA level was significantly increased in STZ group, its level significantly decreased in the PO group. Our results showed that PO has a positive effect on the GSH, total protein, and MDA levels in the brain tissue of diabetic rats. The PO and STZ administrations were affected by levels of some important fatty acids. The decrease in the MDA level and observed protecting effects can be attributed to PO extract, because it contains some important phytochemical constituents. (author)

  20. Herba Artemisiae Capillaris Extract Prevents the Development of Streptozotocin-Induced Diabetic Nephropathy of Rat

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    Jianan Geng

    2018-01-01

    Full Text Available Diabetic nephropathy (DN is a major cause of end-stage renal disease throughout the world; until now there is no specific drug available. In this work, we use herba artemisiae capillaris extract (HACE to alleviate renal fibrosis characterized by the excessive accumulation of extracellular matrix (ECM in rats, aiming to investigate the protective effect of the HACE on DN. We found that the intragastric treatment of high-dose HACE could reverse the effect of streptozotocin not only to decrease the level of blood glucose and blood lipid in different degree but also further to improve renal functions. It is worth mentioning that the effect of HACE treatment was comparable to the positive drug benazepril. Moreover, we found that HACE treatment could on one hand inhibit oxidative stress in DN rats through regulating enzymatic activity for scavenging reactive oxygen species and on the other hand increase the ECM degradation through regulating the activity of metalloproteinase-2 (MMP-2 and the expression of tissue transglutaminase (tTG, which explained why HACE treatment inhibited ECM accumulation. On the basis of above experimental results, we conclude that HACE prevents DN development in a streptozotocin-induced DN rat model, and HACE is a promising candidate to cure DN in clinic.

  1. Morphology of bronchial epithelium in rodent streptozotocin-induced diabetes mellitus

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    Oksana Anatolyevna Pivovarova

    2013-12-01

    Full Text Available Aim. To study the morphology of bronchial epithelium in a rodent streptozotocin-induced (STZ diabetes mellitus.Materials and Methods. Diabetes mellitus was introduced in 47 white Wistar rats aged 5–6 months (body weight 234.0±2.64 g. 43 white Wistar rats of the same age were used as control subjects (body weight 242.0±2.13. Diabetes was induced by single intraperitoneal injection of STZ (SIGMA, USA 60 mg/kg in 0.1 M citrate buffer, pH 4.5.Results. A statistically significant decrease in the total epithelial area by 25.9% was observed in the study group, accompanied by a reduction of the supranuclear zone by 22.1% vs. the control group.Conclusion. We found that bronchial mucous membrane in rodents with STZ-induced diabetes mellitus exhibits signs of atrophy and partial loss of mucous production by bronchial secretory cells.

  2. Magnesium protects cognitive functions and synaptic plasticity in streptozotocin-induced sporadic Alzheimer's model.

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    Zhi-Peng Xu

    Full Text Available Alzheimer's disease (AD is characterized by profound synapse loss and impairments of learning and memory. Magnesium affects many biochemical mechanisms that are vital for neuronal properties and synaptic plasticity. Recent studies have demonstrated that the serum and brain magnesium levels are decreased in AD patients; however, the exact role of magnesium in AD pathogenesis remains unclear. Here, we found that the intraperitoneal administration of magnesium sulfate increased the brain magnesium levels and protected learning and memory capacities in streptozotocin-induced sporadic AD model rats. We also found that magnesium sulfate reversed impairments in long-term potentiation (LTP, dendritic abnormalities, and the impaired recruitment of synaptic proteins. Magnesium sulfate treatment also decreased tau hyperphosphorylation by increasing the inhibitory phosphorylation of GSK-3β at serine 9, thereby increasing the activity of Akt at Ser473 and PI3K at Tyr458/199, and improving insulin sensitivity. We conclude that magnesium treatment protects cognitive function and synaptic plasticity by inhibiting GSK-3β in sporadic AD model rats, which suggests a potential role for magnesium in AD therapy.

  3. Effect of irradiation on the acinar cells of submandibular gland in streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Lee, Seung Hyun; Hwang, Eui Hwan; Lee, Sang Rae

    2003-01-01

    To observe the histologic changes and clusterin expression in the acinar cells of the submandibular gland in streptozotocin-induced diabetic rat following irradiation. Mature Sprague-Dawley rats were divided into three groups: control, diabetic, and diabetic-irradiated groups. Diabetes mellitus was induced in the Sprague-Dawley rats by injecting streptozotocin, while the control rats were injected with citrate buffer only. After 5 days, rats in diabetic-irradiated group were irradiated with single absorbed dose of 10 Gy to the head and neck region. The rats were killed at 1, 3, 7, 14, 21, and 28 days after irradiation. The specimen including the submandibular gland were sectioned and observed using histologic and immunohistochemical methods. Morphologic change of acinar cells was remarkable in the diabetic group, but was not observed in the diabetic-irradiated group. Necrotic tissues were observed in the diabetic-irradiated group. Coloring of toluidine blue stain was most increased at 14 days in the diabetic group, however there were no significant change throughout the period of the experiment in the diabetic-irradiated group. Expression of clusterin was most significant at 14 days in the diabetic group, but gradually decreased with time after 7 days in the diabetic-irradiated group. Degeneration of clusterin was observed in the diabetic-irradiated group. This experiment suggests that the acinar cells of submandibular gland in rats are physiologically apoptosis by the induction of diabetes, but that the apoptosis is inhibited and the acinar cells necrotized after irradiation.

  4. Taenia crassiceps Infection Attenuates Multiple Low-Dose Streptozotocin-Induced Diabetes

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    Arlett Espinoza-Jiménez

    2010-01-01

    Full Text Available Taenia crassiceps, like other helminths, can exert regulatory effects on the immune system of its host. This study investigates the effect of chronic T. crassiceps infection on the outcome of Multiple Low Dose Streptozotocin-Induced Diabetes (MLDS. Healthy or previously T. crassiceps-infected mice received MLDS and type 1 diabetes (T1D symptoms were evaluated for 6 weeks following the induction of MLDS. T. crassiceps-infected mice displayed lower blood glucose levels throughout the study. A significantly lower percentage of T. crassiceps-infected mice (40% developed T1D compared to the uninfected group (100%. Insulitis was remarkably absent in T. crassiceps-infected mice, which had normal pancreatic insulin content, whereas uninfected mice showed a dramatic reduction in pancreatic insulin. Infected mice that received MLDS did not show an increase in their regulatory T cell population, however, they had a greater number of alternatively activated macrophages, higher levels of the cytokine IL-4, and lower levels of TNF-α. Therefore, infection with T. crassiceps causes an immunomodulation that modifies the incidence and development of MLDS-induced autoimmune diabetes.

  5. Proton microprobe analysis of pancreatic. beta. cells

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    Lindh, U [Uppsala Univ. (Sweden). Gustaf Werner Inst.; Juntti-Berggren, L; Berggren, P O; Hellman, B [Uppsala Univ. (Sweden)

    1985-01-01

    Freeze-dried pancreas sections from obese hyperglycemic mice were subjected to proton bombardment and the elemental contents in the ..beta.. cells and the exocrine part were obtained from the characteristic X-rays emitted. Quantitative data were provided for 18 different elements. The mole ratio between K and Na exceeded 10, implying that neither the sample preparation nor the irradiation had induced significant diffuse changes. With the demonstration of this high K/Na ratio it seems likely that also the ..beta.. cells are equipped with an efficient Na/sup +//K/sup +/ pump. The ..beta.. cells contained about 70 mmoles Cl per litre cell water. Observed amounts of Ca and Mg were equivalent to those previously recorded by electrothermal atomic absorption spectroscopy. The significant role of Zn for the storage of insulin was emphasized by the demonstration of 3 times as much of this element in the ..beta.. cells as compared with the exocrine pancreas. In addition, the sensitivity of the proton microprobe enabled measurements of various trace elements such as Rb, Cr, Cu, Al and Pb not previously demonstrated in the pancreatic ..beta.. cells.

  6. Intermittent fasting preserves beta-cell mass in obesity-induced diabetes via the autophagy-lysosome pathway.

    Science.gov (United States)

    Liu, Haiyan; Javaheri, Ali; Godar, Rebecca J; Murphy, John; Ma, Xiucui; Rohatgi, Nidhi; Mahadevan, Jana; Hyrc, Krzysztof; Saftig, Paul; Marshall, Connie; McDaniel, Michael L; Remedi, Maria S; Razani, Babak; Urano, Fumihiko; Diwan, Abhinav

    2017-01-01

    Obesity-induced diabetes is characterized by hyperglycemia, insulin resistance, and progressive beta cell failure. In islets of mice with obesity-induced diabetes, we observe increased beta cell death and impaired autophagic flux. We hypothesized that intermittent fasting, a clinically sustainable therapeutic strategy, stimulates autophagic flux to ameliorate obesity-induced diabetes. Our data show that despite continued high-fat intake, intermittent fasting restores autophagic flux in islets and improves glucose tolerance by enhancing glucose-stimulated insulin secretion, beta cell survival, and nuclear expression of NEUROG3, a marker of pancreatic regeneration. In contrast, intermittent fasting does not rescue beta-cell death or induce NEUROG3 expression in obese mice with lysosomal dysfunction secondary to deficiency of the lysosomal membrane protein, LAMP2 or haplo-insufficiency of BECN1/Beclin 1, a protein critical for autophagosome formation. Moreover, intermittent fasting is sufficient to provoke beta cell death in nonobese lamp2 null mice, attesting to a critical role for lysosome function in beta cell homeostasis under fasting conditions. Beta cells in intermittently-fasted LAMP2- or BECN1-deficient mice exhibit markers of autophagic failure with accumulation of damaged mitochondria and upregulation of oxidative stress. Thus, intermittent fasting preserves organelle quality via the autophagy-lysosome pathway to enhance beta cell survival and stimulates markers of regeneration in obesity-induced diabetes.

  7. A mixture of extracts from Peruvian plants (black maca and yacon) improves sperm count and reduced glycemia in mice with streptozotocin-induced diabetes.

    Science.gov (United States)

    Gonzales, Gustavo F; Gonzales-Castañeda, Cynthia; Gasco, Manuel

    2013-09-01

    We investigated the effect of two extracts from Peruvian plants given alone or in a mixture on sperm count and glycemia in streptozotocin-diabetic mice. Normal or diabetic mice were divided in groups receiving vehicle, black maca (Lepidium meyenii), yacon (Smallanthus sonchifolius) or three mixtures of extracts black maca/yacon (90/10, 50/50 and 10/90%). Normal or diabetic mice were treated for 7 d with each extract, mixture or vehicle. Glycemia, daily sperm production (DSP), epididymal and vas deferens sperm counts in mice and polyphenol content, and antioxidant activity in each extract were assessed. Black maca (BM), yacon and the mixture of extracts reduced glucose levels in diabetic mice. Non-diabetic mice treated with BM and yacon showed higher DSP than those treated with vehicle (p maca/yacon increased DSP, and sperm count in vas deferens and epididymis with respect to non-diabetic and diabetic mice treated with vehicle (p maca, and this was associated with higher antioxidant activity. The combination of two extracts improved glycemic levels and male reproductive function in diabetic mice. Streptozotocin increased 1.43 times the liver weight that was reversed with the assessed plants extracts. In summary, streptozotocin-induced diabetes resulted in reduction in sperm counts and liver damage. These effects could be reduced with BM, yacon and the BM+yacon mixture.

  8. Effect of exogenous leptin on serum levels of lipids, glucose, renal and hepatic variables in both genders of obese and streptozotocin-induced diabetic rats

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    Parichehr Hayatdavoudi

    2015-11-01

    Full Text Available Objective(s: Leptin exerts various effects on appetite and body weight. Disruption of the obesitygene is precedent to fatness. Insulin or glucose elevates leptin, but streptozotocin reduces it. However, controversial data exist for the effects of leptin on diabetes and leptin level in each gender. Leptin can damage the kidney function but little evidence exists for its hepatic effects. The aim of this study was to investigate the probable sex-dependent differences in blood sugar levels, lipid profile, and renal and hepatic biochemical factors in the obesity and streptozotocin-induced diabetic rats after leptin administration. Materials and Methods: Wistar rats of both sexes were randomly divided into two groups, namely obese and diabetic rats. Each group was further divided into male and female subgroups. Extra fat and carbohydrate was added to the diet to induce obesity. Furthermore, streptozotocin (55 mg/kg, IP was injected to induce diabetes. The treatment groups received leptin (0.1 mg/kg SC for 10 days, and then, blood samples were taken from the orbital sinus for laboratory evaluations. Results: Leptin resulted in a significant weight loss in both sexes (P

  9. Attenuating effect of seeds of Adenanthera pavonina aqueous extract in neuropathic pain in streptozotocin-induced diabetic rats: an evidence of neuroprotective effects

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    Ramdas B Pandhare

    2012-04-01

    Full Text Available The aim of present study was to investigate the attenuating effects of Adenanthera pavonina L., Leguminosae-Mimosaceae seeds aqueous extract (APSAE, in streptozotocin (STZ-induced diabetic neuropathy in rats. APSAE (50, 100 and 200 mg/kg per day was given to diabetic rats for twelve weeks. Cold and hot water tail immersion tests, photoactometer and Rota-rod tests were performed to assess degree of colder, thermal, spontaneous motor activity and motor co-ordination changes respectively at different time intervals i.e., week 0, 4, 8 and 12. Tissue superoxide anion and total calcium levels were determined after twelve weeks to assess biochemical alterations. Histopathological evaluations of sciatic nerve were also performed to assess nerve damage. APSAE treatment increased tail flick latency significantly in diabetic rats. APSAE also reduced superoxide anion and total calcium levels. These results suggested that APSAE has attenuated development of diabetic neuropathy in streptozotocin-induced diabetic rats when compared with pregabalin (10 mg/kg, p.o. and could be beneficial in preventing the progression of diabetic nephropathy.

  10. Streptozotocin-induced diabetes mellitus affects lysosomal enzymes in rat liver

    Directory of Open Access Journals (Sweden)

    G.B. Peres

    2014-06-01

    Full Text Available It has been previously shown that dextran sulfate administered to diabetic rats accumulates in the liver and kidney, and this could be due to a malfunction of the lysosomal digestive pathway. The aim of the present study was to evaluate the expression and activities of lysosomal enzymes that act upon proteins and sulfated polysaccharides in the livers of diabetic rats. Diabetes mellitus was induced by streptozotocin in 26 male Wistar rats (12 weeks old, while 26 age-matched controls received only vehicle. The livers were removed on either the 10th or the 30th day of the disease, weighed, and used to evaluate the activity, expression, and localization of lysosomal enzymes. A 50-60% decrease in the specific activities of cysteine proteases, especially cathepsin B, was observed in streptozotocin-induced diabetes mellitus. Expression (mRNA of cathepsins B and L was also decreased on the 10th, but not on the 30th day. Sulfatase decreased 30% on the 30th day, while glycosidases did not vary (or presented a transitory and slight decrease. There were no apparent changes in liver morphology, and immunohistochemistry revealed the presence of cathepsin B in hepatocyte granules. The decrease in sulfatase could be responsible for the dextran sulfate build-up in the diabetic liver, since the action of sulfatase precedes glycosidases in the digestive pathway of sulfated polysaccharides. Our findings suggest that the decreased activities of cathepsins resulted from decreased expression of their genes, and not from general lysosomal failure, because the levels of glycosidases were normal in the diabetic liver.

  11. [Effect of compound Puerarin on the collage IV in streptozotocin-induced diabetic nephropathy rats].

    Science.gov (United States)

    Li, Qiang-xiang; Zhong, Hui-ju; Gong, Han-ren; Zhu, Fei-yue; Wang, Lin-na; Shen, Dao-jun; Li, Guo; Wang, Cai-yun; Qin, Cheng-sheng

    2008-04-01

    To observe the effect of compound Puerarin on collagen IV of streptozotocin-induced diabetic rats. Diabetic nephropathy rats were induced by intraperitoneal injection of streptozotocin (STZ). Rats were allocated randomly to control group (10), diabetes model group (10), Vitamin C group (10), Puerarin group (10), vitamin C plus Puerarin group (10). The study period lasted for 12 weeks. During and after the treatment, the general state, blood glucose levels, glycosylated hemoglobin, blood urea nitrogen, serum collagen IV, blood urea nitrogen, serum creatinine, urinary albumin excretion rate of the 24-hour, and clearance rate of creatinine collagen IV protein were determined by immunohistochemistoche analysis as well as type the gene expression of collagen IV alpha 1 mRNA were determined by in situ hybridization analysis in the kidney tissue of different groups. (1) Diabetes mellitus and renal function lesion occurred in the four groups. (2) Vitamin C and Puerarin could improve the general conditions of diabetic Rats, decrease blood urea nitrogen [(8.68 +/- 0.43), (7.98 +/- 0.47) and (5.76 +/- 0.82) micromol/L, serum creatinine [(74.68 +/- 8.20), (75.52 +/- 7.98) and (58.66 +/- 6.65) mmol/L], and urinary albumin excretion rate of the 24-hour [(18.40 +/- 0.37), (17.24 +/- 0.30) and (9.97 +/- 1.27) mg/24 h x 10(-3)]; increase clearance rate of creatinine [(0.59 +/- 0.21), (0.61 +/- 0.14) and (0.69 +/- 0.32) ml/min], the expression of collage IV absorbance [(111.56 +/- 14.61), (110.78 +/- 9.69) and (95.44 +/- 9.97) ] in the diabetic Rats were significantly inhibited at the same time. The compound Puerarin might have some functions on preventing ren by inhibiting expression of type IV collagen.

  12. Lacking Ketohexokinase-A Exacerbates Renal Injury in Streptozotocin-induced Diabetic Mice.

    Science.gov (United States)

    Doke, Tomohito; Ishimoto, Takuji; Hayasaki, Takahiro; Ikeda, Satsuki; Hasebe, Masako; Hirayama, Akiyoshi; Soga, Tomoyoshi; Kato, Noritoshi; Kosugi, Tomoki; Tsuboi, Naotake; Lanaspa, Miguel A; Johnson, Richard J; Kadomatsu, Kenji; Maruyama, Shoichi

    2018-03-28

    Ketohexokinase (KHK), a primary enzyme in fructose metabolism, has two isoforms, namely, KHK-A and KHK-C. Previously, we reported that renal injury was reduced in streptozotocin-induced diabetic mice which lacked both isoforms. Although both isoforms express in kidney, it has not been elucidated whether each isoform plays distinct roles in the development of diabetic kidney disease (DKD). The aim of the study is to elucidate the role of KHK-A for DKD progression. Diabetes was induced by five consecutive daily intraperitoneal injections of streptozotocin (50 mg/kg) in C57BL/6 J wild-type mice, mice lacking KHK-A alone (KHK-A KO), and mice lacking both KHK-A and KHK-C (KHK-A/C KO). At 35 weeks, renal injury, inflammation, hypoxia, and oxidative stress were examined. Metabolomic analysis including polyol pathway, fructose metabolism, glycolysis, TCA (tricarboxylic acid) cycle, and NAD (nicotinamide adenine dinucleotide) metabolism in kidney and urine was done. Diabetic KHK-A KO mice developed severe renal injury compared to diabetic wild-type mice, and this was associated with further increases of intrarenal fructose, dihydroxyacetone phosphate (DHAP), TCA cycle intermediates levels, and severe inflammation. In contrast, renal injury was prevented in diabetic KHK-A/C KO mice compared to both wild-type and KHK-A KO diabetic mice. Further, diabetic KHK-A KO mice contained decreased renal NAD + level with the increase of renal hypoxia-inducible factor 1-alpha expression despite having increased renal nicotinamide (NAM) level. These results suggest that KHK-C might play a deleterious role in DKD progression through endogenous fructose metabolism, and that KHK-A plays a unique protective role against the development of DKD. Copyright © 2018. Published by Elsevier Inc.

  13. Effect of irradiation on the temporomandibular joint in streptozotocin-induced diabetic rat

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Ki Dong; Hwang, Eui Hwan; Lee, Sang Rae [Kyunghee University College of Medicine, Seoul (Korea, Republic of)

    2004-06-15

    To investigate the histopathological changes in the temporomandibular joint in streptozotocin-induced diabetic rat following irradiation. Sprague-Dawley rats weighing about 250 gm were divided into three groups: control, diabetic, and diabetic-irradiated groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control group were injected with citrate buffer only. After 5 days, the head and neck region of the rats in diabetic-irradiated group were irradiated with single absorbed dose of 10 Gy. The rats were killed at 1, 3, 7, 14, 21, and 28 days after irradiation. The specimen including the temporomandibular joint were sectioned and observed using a histopathological method. In the diabetic group, severe bone resorption in the mandibular condyle was observed throughout the period of experiment. Necrosis of bone marrow and trabeculae was observed at 28 days after diabetic state. Atrophy and fibrosis in the retrodiscal tissue was gradually progressed during the time of the experiment. In the diabetic-irradiated group, severe bone resorption in the mandibular condyle was observed during the early experimental phases, but regeneration of bone marrow was initiated at 14 days after diabetic state and irradiation. Also, calcification of abnormal trabeculae was observed at 28 days after diabetic state and irradiation. The retrodiscal tissue was degenerated in the early experimental phases, but it had been gradually regenerated during the experimental time. This experiment suggests that bone resorption and degeneration in the mandibular condyle are caused by the induction of diabetes, and abnormal bone formation is induced after irradiation in diabetic state.

  14. Effect of irradiation on the periodontal tissues in streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Park, Dong Sin; Hwang, Eui Hwan; Lee, Sang Rae

    2005-01-01

    To observe the histopathological changes in the periodontal tissues of mandibular molars in streptozotocin-induced diabetic rats after irradiation. The male Sprague-Dawley rats weighing approximately 250 gm were divided into four groups; control, diabetes, irradiation, and diabetes - irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control and irradiation groups were injected with citrate buffer only. After 5 days, the head and neck region of the rats in irradiation and diabetes - irradiation groups were irradiated with a single absorbed dose of 10 Gy. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the mandibular molars were sectioned and observed using a histopathological method. In the diabetes group, osteoclastic activity was observed in the alveolar bone and the root throughout the period of experiment. Also, osteoblastic and fibroblastic activities were markedly decreased. In the irradiation group, the osteoclasts were observed in the alveolar bone and the dilated capillaries were increased in the early experimental phases. However, vigorous osteoblastic activity was noted in the late experimental phases. In the diabetes- irradiation group, osteoblastic activity in the alveolar bone and the root was observed in the early experimental phases. However, there were no resorption and osteoblastic activity in the alveolar bone and the root in the late experimental phases, and obvious atrophic change of fibrous tissues was noted. This experiment suggests that osteoblastic activity was caused by irradiation in the late experimental phases, but atrophic change of the periodontal ligament tissues was induced after irradiation in diabetic state.

  15. Diacylglycerol kinase ζ inhibits myocardial atrophy and restores cardiac dysfunction in streptozotocin-induced diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Sasaki Toshiki

    2008-02-01

    Full Text Available Abstract Background Activation of the diacylglycerol (DAG-protein kinase C (PKC pathway has been implicated in the pathogenesis of a number of diabetic complications. Diacylglycerol kinase (DGK converts DAG to phosphatidic acid and acts as an endogenous regulator of PKC activity. Akt/PKB is associated with a downstream insulin signaling, and PKCβ attenuates insulin-stimulated Akt phosphorylation. Methods and Results We examined transgenic mice with cardiac-specific overexpression of DGKζ (DGKζ-TG compared to wild type (WT mice in streptozotocin-induced (STZ, 150 mg/kg diabetic and nondiabetic conditions. After 8 weeks, decreases in heart weight and heart weight/body weight ratio in diabetic WT mice were inhibited in DGKζ-TG mice. Echocardiography at 8 weeks after STZ-injection demonstrated that decreases in left ventricular end-diastolic diameter and fractional shortening observed in WT mice were attenuated in DGKζ-TG mice. Thinning of the interventricular septum and the posterior wall in diabetic WT hearts were blocked in DGKζ-TG mice. Reduction of transverse diameter of cardiomyocytes isolated from the left ventricle in diabetic WT mice was attenuated in DGKζ-TG mice. Cardiac fibrosis was much less in diabetic DGKζ-TG than in diabetic WT mice. Western blots showed translocation of PKCβ and δ isoforms to membrane fraction and decreased Akt/PKB phosphorylation in diabetic WT mouse hearts. However in diabetic DGKζ-TG mice, neither translocation of PKC nor changes Akt/PKB phosphorylation was observed. Conclusion DGKζ modulates intracellular signaling and improves the course of diabetic cardiomyopathy. These data may suggest that DGKζ is a new therapeutic target to prevent or reverse diabetic cardiomyopathy.

  16. Streptozotocin-induced diabetes mellitus affects lysosomal enzymes in rat liver

    International Nuclear Information System (INIS)

    Peres, G.B.; Juliano, M.A.; Aguiar, J.A.K.; Michelacci, Y.M.

    2014-01-01

    It has been previously shown that dextran sulfate administered to diabetic rats accumulates in the liver and kidney, and this could be due to a malfunction of the lysosomal digestive pathway. The aim of the present study was to evaluate the expression and activities of lysosomal enzymes that act upon proteins and sulfated polysaccharides in the livers of diabetic rats. Diabetes mellitus was induced by streptozotocin in 26 male Wistar rats (12 weeks old), while 26 age-matched controls received only vehicle. The livers were removed on either the 10 th or the 30 th day of the disease, weighed, and used to evaluate the activity, expression, and localization of lysosomal enzymes. A 50-60% decrease in the specific activities of cysteine proteases, especially cathepsin B, was observed in streptozotocin-induced diabetes mellitus. Expression (mRNA) of cathepsins B and L was also decreased on the 10 th , but not on the 30 th day. Sulfatase decreased 30% on the 30 th day, while glycosidases did not vary (or presented a transitory and slight decrease). There were no apparent changes in liver morphology, and immunohistochemistry revealed the presence of cathepsin B in hepatocyte granules. The decrease in sulfatase could be responsible for the dextran sulfate build-up in the diabetic liver, since the action of sulfatase precedes glycosidases in the digestive pathway of sulfated polysaccharides. Our findings suggest that the decreased activities of cathepsins resulted from decreased expression of their genes, and not from general lysosomal failure, because the levels of glycosidases were normal in the diabetic liver

  17. Mulberry Leaf Extract Attenuates Oxidative Stress-Mediated Testosterone Depletion in Streptozotocin-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Hajizadeh

    2014-03-01

    Streptozotocin-Induced Diabetic Rats. Iran J Med Sci. 2014;39(2:123-129.

  18. Streptozotocin-induced diabetes mellitus affects lysosomal enzymes in rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Peres, G.B. [Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Bioquímica, São Paulo, SP, Brasil, Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Juliano, M.A. [Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Biofísica, São Paulo, SP, Brasil, Departamento de Biofísica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Aguiar, J.A.K.; Michelacci, Y.M. [Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Bioquímica, São Paulo, SP, Brasil, Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil)

    2014-05-09

    It has been previously shown that dextran sulfate administered to diabetic rats accumulates in the liver and kidney, and this could be due to a malfunction of the lysosomal digestive pathway. The aim of the present study was to evaluate the expression and activities of lysosomal enzymes that act upon proteins and sulfated polysaccharides in the livers of diabetic rats. Diabetes mellitus was induced by streptozotocin in 26 male Wistar rats (12 weeks old), while 26 age-matched controls received only vehicle. The livers were removed on either the 10{sup th} or the 30{sup th} day of the disease, weighed, and used to evaluate the activity, expression, and localization of lysosomal enzymes. A 50-60% decrease in the specific activities of cysteine proteases, especially cathepsin B, was observed in streptozotocin-induced diabetes mellitus. Expression (mRNA) of cathepsins B and L was also decreased on the 10{sup th}, but not on the 30{sup th} day. Sulfatase decreased 30% on the 30{sup th} day, while glycosidases did not vary (or presented a transitory and slight decrease). There were no apparent changes in liver morphology, and immunohistochemistry revealed the presence of cathepsin B in hepatocyte granules. The decrease in sulfatase could be responsible for the dextran sulfate build-up in the diabetic liver, since the action of sulfatase precedes glycosidases in the digestive pathway of sulfated polysaccharides. Our findings suggest that the decreased activities of cathepsins resulted from decreased expression of their genes, and not from general lysosomal failure, because the levels of glycosidases were normal in the diabetic liver.

  19. Total saponin of Dioscoreae hypoglaucae rhizoma ameliorates streptozotocin-induced diabetic nephropathy

    Directory of Open Access Journals (Sweden)

    Guo C

    2016-02-01

    Full Text Available Changrun Guo,1 Gang Ding,2 Wenzhe Huang,2 Zhenzhong Wang,2 Zhaoqing Meng,1,2 Wei Xiao2 1State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, People’s Republic of China; 2Jiangsu Kanion Pharmaceutical Co. Ltd, Lianyungang City, People’s Republic of China Background: Diabetic nephropathy has become the most common cause of morbidity and mortality in diabetic patients. Therefore, there is an urgent need for more effective and safer drugs for use in this condition.Purpose: The aims of this study were to investigate the ameliorative effects of total saponin of Dioscoreae hypoglaucae rhizoma (TSD on diabetic nephropathy and to explore the potential underlying mechanism(s.Methods: Rats with streptozotocin-induced diabetes were orally treated with TSD at 40, 80, and 160 mg/kg/d for 12 weeks. At the end of the treatment, blood, urine, and kidneys were collected for biochemical and histological examination.Results: The results demonstrated that TSD significantly decreased the fasting blood glucose, glycosylated hemoglobin, urinary protein, serum creatinine, and blood urea nitrogen levels in diabetic rats. The results of histological examinations showed that TSD ameliorated glomerular and tubular pathological changes in diabetic rats. Furthermore, TSD significantly prevented oxidative stress and reduced the renal levels of advanced glycation end products, transforming growth factor-β1, connective tissue growth factor, and tumor necrosis factor-α.Conclusion: This study demonstrated the renoprotective effects of TSD in experimental diabetic nephropathy via a number of different mechanisms. Keywords: total saponin of Dioscoreae hypoglaucae rhizoma, diabetic nephropathy, oxidative stress, AGEs, TGF-β1

  20. Attenuation of diabetic nephropathy in streptozotocin-induced diabetic rats by Punica granatum Linn. leaves extract

    Directory of Open Access Journals (Sweden)

    Snehal Nitin Mestry

    2017-07-01

    Full Text Available With an objective to develop Complementary and Alternative Medicine for the treatment of diabetic nephropathy, the present study investigated the protective effects of methanolic extract of Punica granatum leaves (MPGL in streptozotocin-induced diabetic nephropathy. Diabetic nephropathy has become a leading cause of end stage renal failure worldwide. P. granatum, due to its anti-diabetic, anti-inflammatory and antioxidant activities may retard the progression of diabetic nephropathy. In this study, diabetes was induced by a single injection of streptozotocin (STZ, 45 mg/kg, i.p. in rats. STZ-diabetic rats were treated with oral doses of MPGL (100, 200 and 400 mg/kg for 8 weeks. At the end of the experimental period, body and kidney weight and blood glucose levels were determined. Serum and urine parameters were investigated. Antioxidant enzymes and lipid peroxide levels were determined in the kidney along with histopathological examination of the same. MPGL significantly increased body weight, lowered blood glucose levels and ameliorated kidney hypertrophy index in the STZ-diabetic rats. The extract also decreased the levels of creatinine, blood urea nitrogen, total cholesterol, triglycerides, advanced glycation end products and albumin in serum and urine, respectively. MPGL significantly increased the antioxidant parameters in the kidney. Histological evaluation revealed that MPGL treated STZ-diabetic rats demonstrated reduced vacuolar degeneration of tubules; periodic acid Schiff base (PAS positivity staining intensity in glomeruli and basement membrane thickening. Present findings provide experimental evidence that MPGL has potential antioxidant, antihyperglycemic and anti-glycation activities which might be helpful in slowing the progression of diabetic nephropathy.

  1. Attenuation of diabetic nephropathy in streptozotocin-induced diabetic rats by Punica granatum Linn. leaves extract.

    Science.gov (United States)

    Mestry, Snehal Nitin; Dhodi, Jayesh Bachu; Kumbhar, Sangita Balbhim; Juvekar, Archana Ramesh

    2017-07-01

    With an objective to develop Complementary and Alternative Medicine for the treatment of diabetic nephropathy, the present study investigated the protective effects of methanolic extract of Punica granatum leaves (MPGL) in streptozotocin-induced diabetic nephropathy. Diabetic nephropathy has become a leading cause of end stage renal failure worldwide. P. granatum , due to its anti-diabetic, anti-inflammatory and antioxidant activities may retard the progression of diabetic nephropathy. In this study, diabetes was induced by a single injection of streptozotocin (STZ, 45 mg/kg, i.p.) in rats. STZ-diabetic rats were treated with oral doses of MPGL (100, 200 and 400 mg/kg) for 8 weeks. At the end of the experimental period, body and kidney weight and blood glucose levels were determined. Serum and urine parameters were investigated. Antioxidant enzymes and lipid peroxide levels were determined in the kidney along with histopathological examination of the same. MPGL significantly increased body weight, lowered blood glucose levels and ameliorated kidney hypertrophy index in the STZ-diabetic rats. The extract also decreased the levels of creatinine, blood urea nitrogen, total cholesterol, triglycerides, advanced glycation end products and albumin in serum and urine, respectively. MPGL significantly increased the antioxidant parameters in the kidney. Histological evaluation revealed that MPGL treated STZ-diabetic rats demonstrated reduced vacuolar degeneration of tubules; periodic acid Schiff base (PAS) positivity staining intensity in glomeruli and basement membrane thickening. Present findings provide experimental evidence that MPGL has potential antioxidant, antihyperglycemic and anti-glycation activities which might be helpful in slowing the progression of diabetic nephropathy.

  2. Effect of irradiation on the temporomandibular joint in streptozotocin-induced diabetic rat

    International Nuclear Information System (INIS)

    Ahn, Ki Dong; Hwang, Eui Hwan; Lee, Sang Rae

    2004-01-01

    To investigate the histopathological changes in the temporomandibular joint in streptozotocin-induced diabetic rat following irradiation. Sprague-Dawley rats weighing about 250 gm were divided into three groups: control, diabetic, and diabetic-irradiated groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control group were injected with citrate buffer only. After 5 days, the head and neck region of the rats in diabetic-irradiated group were irradiated with single absorbed dose of 10 Gy. The rats were killed at 1, 3, 7, 14, 21, and 28 days after irradiation. The specimen including the temporomandibular joint were sectioned and observed using a histopathological method. In the diabetic group, severe bone resorption in the mandibular condyle was observed throughout the period of experiment. Necrosis of bone marrow and trabeculae was observed at 28 days after diabetic state. Atrophy and fibrosis in the retrodiscal tissue was gradually progressed during the time of the experiment. In the diabetic-irradiated group, severe bone resorption in the mandibular condyle was observed during the early experimental phases, but regeneration of bone marrow was initiated at 14 days after diabetic state and irradiation. Also, calcification of abnormal trabeculae was observed at 28 days after diabetic state and irradiation. The retrodiscal tissue was degenerated in the early experimental phases, but it had been gradually regenerated during the experimental time. This experiment suggests that bone resorption and degeneration in the mandibular condyle are caused by the induction of diabetes, and abnormal bone formation is induced after irradiation in diabetic state.

  3. Effect of Simulated Intermittent Altitude on the Metabolic and Hematologic Parameters in Streptozotocin Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    mehdi Faramoushi

    2016-04-01

    Full Text Available Background & objectives: Type II diabetes is a metabolic disorder accompanied with insulin resistance of the whole body cells and is considered be the fifth cause of death in the world. Adaptation to altitude can lead to tolerance to many diseases. Therefore, the aim of this study was to determine the effect of simulated intermittent altitude on the metabolic and hematologic parameters and liver function in streptozotocin induced diabetic rats. Methods: In the current experimental study, twenty four male Wistar rats weighing 220±20 gr were randomly divided into three groups; normal control group (NC, n=8, diabetic control group (D, n=8 received fat diet for 2 weeks then were injected with streptozotocin (37 mg/kg and diabetic+hypoxia group (D+H, n=8 including diabetic rat exposed to chronic intermittent hypoxia (PiO2≈106 mm Hg, simulated altitude≈3400 m, 14% oxygen for 8 weeks. Diabetic, hematologic and lipid parameters as well as ALT and AST activities were measured in peripheral blood. Results: Our findings showed that intermittent hypoxia significantly decreased serum total cholesterol, LDL ,VLDL and triglyceride in D+H group compared to D group (p<0.05. Serum levels of fasting blood glucose and homeostatic model assessment-insulin resistance HOMA-IR( index and ALT were decreased in D+H group vs. D group p<0.05. Also, hemoglubin and hematocrite level increased in D+H group in comparison to D group p<0.05. No significant difference was detected in red blood cell count in D+H vs. D group. Conclusion: Based on resultant data, it seems that intermittent exposure to hypoxia (simulated to chronic and intermittent lodgement in altitude can be used to control of type 2 diabetes by increasing hemoglobin, decreasing insulin resistance and improving liver function as well as lipid parameters.

  4. Studies on the antidiabetic activities of Momordica charantia fruit juice in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Mahmoud, Mona F; El Ashry, Fatma El Zahraa Z; El Maraghy, Nabila N; Fahmy, Ahmed

    2017-12-01

    Momordica charantia Linn (Cucurbitaceae) (MC) is used in folk medicine to treat various diseases including diabetes mellitus. This study investigates the antidiabetic activities of Momordica charantia (bitter gourd) on streptozotocin-induced type 2 diabetes mellitus in rats. Male Wister rats were randomly assigned to 4 groups. Group I, Normal control; Group II, STZ diabetic; Group III and IV, Momordica charantia fruit juice was orally administered to diabetic rats (10 mL/kg/day either as prophylaxis for 14 days before induction of diabetes then 21 days treatment, or as treatment given for 21 days after induction of diabetes). The effects of MC juice were studied both in vivo and in vitro by studying the glucose uptake of isolated rat diaphragm muscles in the presence and absence of insulin. Histopathological examination of pancreas was also performed. This study showed that MC caused a significant reduction of serum glucose (135.99 ± 6.27 and 149.79 ± 1.90 vs. 253.40* ± 8.18) for prophylaxis and treatment respectively, fructosamine (0.99 ± 0.01 and 1.01 ± 0.04 vs. 3.04 ± 0.07), total cholesterol, triglycerides levels, insulin resistance index (1.13 ± 0.08 and 1.19 ± 0.05 vs. 1.48 ± 1.47) and pancreatic malondialdehyde content (p Momordica charantia presents excellent antidiabetic and antioxidant activities and thus has great potential as a new source for diabetes treatment whether it is used for prophylaxis or treatment.

  5. Redox Homeostasis in Pancreatic beta Cells

    Czech Academy of Sciences Publication Activity Database

    Ježek, Petr; Dlasková, Andrea; Plecitá-Hlavatá, Lydie

    2012-01-01

    Roč. 2012, č. 2012 (2012), s. 932838 ISSN 1942-0900 R&D Projects: GA ČR(CZ) GAP302/10/0346; GA ČR(CZ) GPP304/10/P204 Institutional support: RVO:67985823 Keywords : beta cells * reactive oxygen species homeostasis * mitochondria Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 3.393, year: 2012

  6. ROS signaling, oxidative stress and Nrf2 in pancreatic beta-cell function

    International Nuclear Information System (INIS)

    Pi Jingbo; Zhang Qiang; Fu Jingqi; Woods, Courtney G.; Hou Yongyong; Corkey, Barbara E.; Collins, Sheila; Andersen, Melvin E.

    2010-01-01

    This review focuses on the emerging evidence that reactive oxygen species (ROS) derived from glucose metabolism, such as H 2 O 2 , act as metabolic signaling molecules for glucose-stimulated insulin secretion (GSIS) in pancreatic beta-cells. Particular emphasis is placed on the potential inhibitory role of endogenous antioxidants, which rise in response to oxidative stress, in glucose-triggered ROS and GSIS. We propose that cellular adaptive response to oxidative stress challenge, such as nuclear factor E2-related factor 2 (Nrf2)-mediated antioxidant induction, plays paradoxical roles in pancreatic beta-cell function. On the one hand, induction of antioxidant enzymes protects beta-cells from oxidative damage and possible cell death, thus minimizing oxidative damage-related impairment of insulin secretion. On the other hand, the induction of antioxidant enzymes by Nrf2 activation blunts glucose-triggered ROS signaling, thus resulting in reduced GSIS. These two premises are potentially relevant to impairment of beta-cells occurring in the late and early stage of Type 2 diabetes, respectively. In addition, we summarized our recent findings that persistent oxidative stress due to absence of uncoupling protein 2 activates cellular adaptive response which is associated with impaired pancreatic beta-cell function.

  7. Beneficial Effect of Jojoba Seed Extracts on Hyperglycemia-Induced Oxidative Stress in RINm5f Beta Cells.

    Science.gov (United States)

    Belhadj, Sahla; Hentati, Olfa; Hamdaoui, Ghaith; Fakhreddine, Khaskhoussi; Maillard, Elisa; Dal, Stéphanie; Sigrist, Séverine

    2018-03-20

    Hyperglycemia occurs during diabetes and insulin resistance. It causes oxidative stress by increasing reactive oxygen species (ROS) levels, leading to cellular damage. Polyphenols play a central role in defense against oxidative stress. In our study, we investigated the antioxidant properties of simmondsin, a pure molecule present in jojoba seeds, and of the aqueous extract of jojoba seeds on fructose-induced oxidative stress in RINm5f beta cells. The exposure of RINm5f beta cells to fructose triggered the loss of cell viability (-48%, p jojoba seed extract makes jojoba a powerful agent to prevent the destruction of RINm5f beta cells induced by hyperglycemia.

  8. Role of digitalis-like substance in the hypertension of streptozotocin-induced diabetes and simulated weightlessness in rats

    Science.gov (United States)

    Pamnani, M. B.; Chen, S.; Haddy, F. J.; Yuan, C.; Mo, Z.

    1998-01-01

    We have examined the role of plasma Na+-K+ pump inhibitor (SPI) in the hypertension of streptozotocin induced insulin dependent diabetes (IDDM) in reduced renal mass rats. The increase in blood pressure (BP) was associated with an increase in extracellular fluid volume (ECFV), and SPI and a decrease in myocardial Na+,K+ATPase (NKA) activity, suggesting that increased SPI, which inhibits cardiovascular muscle (CVM) cell NKA activity, may be involved in the mechanism of IDDM-hypertension. In a second study, using prolonged suspension resulted in a decrease in cardiac NKA activity, suggesting that cardiovascular deconditioning following space flight might in part result from insufficient SPI.

  9. The Role of Oxidative Stress and Hypoxia in Pancreatic Beta-Cell Dysfunction in Diabetes Mellitus.

    Science.gov (United States)

    Gerber, Philipp A; Rutter, Guy A

    2017-04-01

    Metabolic syndrome is a frequent precursor of type 2 diabetes mellitus (T2D), a disease that currently affects ∼8% of the adult population worldwide. Pancreatic beta-cell dysfunction and loss are central to the disease process, although understanding of the underlying molecular mechanisms is still fragmentary. Recent Advances: Oversupply of nutrients, including glucose and fatty acids, and the subsequent overstimulation of beta cells, are believed to be an important contributor to insulin secretory failure in T2D. Hypoxia has also recently been implicated in beta-cell damage. Accumulating evidence points to a role for oxidative stress in both processes. Although the production of reactive oxygen species (ROS) results from enhanced mitochondrial respiration during stimulation with glucose and other fuels, the expression of antioxidant defense genes is unusually low (or disallowed) in beta cells. Not all subjects with metabolic syndrome and hyperglycemia go on to develop full-blown diabetes, implying an important role in disease risk for gene-environment interactions. Possession of common risk alleles at the SLC30A8 locus, encoding the beta-cell granule zinc transporter ZnT8, may affect cytosolic Zn 2+ concentrations and thus susceptibility to hypoxia and oxidative stress. Loss of normal beta-cell function, rather than total mass, is increasingly considered to be the major driver for impaired insulin secretion in diabetes. Better understanding of the role of oxidative changes, its modulation by genes involved in disease risk, and effects on beta-cell identity may facilitate the development of new therapeutic strategies to this disease. Antioxid. Redox Signal. 26, 501-518.

  10. Effect of Syzygium Aromaticum (CLOVE) Extract on Blood Glucose Level in Streptozotocin induced Diabetic Rats

    International Nuclear Information System (INIS)

    Chaudhry, Z. R.; Chaudhry, S. R.; Naseer, A.; Chaudhry, F. R.

    2013-01-01

    Objective: To evaluate the glucose lowering effect of 50% ethanol extract of Syzygium aromaticum in comparison with that of standard insulin in streptozotocin induced diabetic rats. Study Design: Randomized control trial. Place and Duration of Study: National Institute of Health Islamabad. Jul 2011- Dec 2011 Material and Methods: It was carried out on 48 adult rats of Sprague dawley specie. Rats were equally divided into 6 groups (I-VI). Group - I served as control. Diabetes was induced by giving single intraperitoneal injection of STZ in Group II to VI. Group-II served as diabetic control, while groups III, IV, V and VI served as experimental groups. Group III, IV and V rats received 50% ethanol extract of Syzygium aromaticum at a dose of 250, 500 and 750 mg/kg body weight respectively for sixty days. Group VI (standard) received humulin insulin 70/30 at dose of 0.6 units<-kg body weight subcutaneously bid for sixty days. Fasting blood samples were taken at zero day, 15 day, 30 day and 60 day after giving injection STZ. Although Syzygium aromaticum with the doses of 250, 500 and 750 mg/kg body weight and insulin reduced the level of glucose in rats but on comparison Syzygium aromaticum 750 mg=kg dose reduced glucose more effectively than 250 and 500 mg/kg dose. While in group III, IV subjects, blood glucose levels remained above normal level. In group VI receiving insulin the level of this parameter remained almost closer to group IV rats. On studying the weight of the animals after receiving STZ there was initial reduction in the weight of all the experimental groups but after receiving the extract of plant improvement was seen and the weight of group V getting 750 mg=kg/body weight of Syzygium aromaticum became almost closer to the weight of control group. Conclusion: Syzygium aromaticum extract has glucose lowering effect in STZ induced diabetic rats and this effect is dose related and the dose of 750 mg/kg body weight has produced maximum effect. (author)

  11. Effect of naringerin on biochemical parameters in the streptozotocin-induced diabetic rats

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    Ana Angélica Henrique Fernandes

    2009-02-01

    Full Text Available Amongst the numerous co-adjuvant therapies which could influence the incidence and progression of diabetic complications, antioxidants and flavonoids are currently being tested in clinical trials. We investigated the effect of naringerin on biochemical parameters in streptozotocin-induced (STZ - 60 mg/kg, i.p. diabetic rats. Male rats were divided into four groups: G1: untreated controls; G2: normal rats receiving naringerin; G3: untreated diabetics; G4: diabetics rats receiving naringerin. The naringerin (50mg/kg, i.p, decreased the hyperglycaemia and hyperlipidaemia associated with STZ-diabetes. The concentrations of serum insulin in treated diabetic rats tended to be increased. Naringerin treatment prevents STZ-induced changes in the activities of ALT, AST and LDH in the liver and heart, indicating the protective effect of naringerin against the hepatic and cardiac toxicity caused by STZ. The glycogen level in cardiac and hepatic tissues elevated with naringerin in diabetic rats. The naringerin can improve the glucose and lipid metabolism and is beneficial in preventing diabetic complications.Dentre as numerosas terapias para minimizar as complicações diabéticas, os antioxidantes e flavonoides são testados na clínica médica. Foi analisado o efeito da naringerina sobre os parâmetros bioquímicos em ratos diabéticos induzidos por estreptozotocina (STZ - 60mg/kg, i.p.. Ratos machos foram divididos em 4 grupos: G1: controle não tratado; G2: ratos normais que receberam naringerina; G3: diabéticos não tratados; G4: ratos diabéticos que receberam naringerina. Naringerina (50mg/kg, i.p., decresceu a hiperglicemia e a hiperlipidemia em ratos diabéticos. A concentração sérica de insulina em ratos tratados tendeu aumentar. A naringerina preveniu as alterações, provocadas pela estreptozotocina, na atividade hepática e cardíaca de ALT, AST e LDH, indicando o efeito protetor da naringerina sobre estes tecidos, contra toxicidade

  12. Inflammatory stress of pancreatic beta cells drives release of extracellular heat-shock protein 90α.

    Science.gov (United States)

    Ocaña, Gail J; Pérez, Liliana; Guindon, Lynette; Deffit, Sarah N; Evans-Molina, Carmella; Thurmond, Debbie C; Blum, Janice S

    2017-06-01

    A major obstacle in predicting and preventing the development of autoimmune type 1 diabetes (T1D) in at-risk individuals is the lack of well-established early biomarkers indicative of ongoing beta cell stress during the pre-clinical phase of disease. Recently, serum levels of the α cytoplasmic isoform of heat-shock protein 90 (hsp90) were shown to be elevated in individuals with new-onset T1D. We therefore hypothesized that hsp90α could be released from beta cells in response to cellular stress and inflammation associated with the earliest stages of T1D. Here, human beta cell lines and cadaveric islets released hsp90α in response to stress induced by treatment with a combination of pro-inflammatory cytokines including interleukin-1β, tumour necrosis factor-α and interferon-γ. Mechanistically, hsp90α release was found to be driven by cytokine-induced endoplasmic reticulum stress mediated by c-Jun N-terminal kinase (JNK), a pathway that can eventually lead to beta cell apoptosis. Cytokine-induced beta cell hsp90α release and JNK activation were significantly reduced by pre-treating cells with the endoplasmic reticulum stress-mitigating chemical chaperone tauroursodeoxycholic acid. The hsp90α release by cells may therefore be a sensitive indicator of stress during inflammation and a useful tool in assessing therapeutic mitigation of cytokine-induced cell damage linked to autoimmunity. © 2017 John Wiley & Sons Ltd.

  13. Characterization of a Commercial Silicon Beta Cell

    International Nuclear Information System (INIS)

    Foxe, Michael P.; Hayes, James C.; Mayer, Michael F.; McIntyre, Justin I.; Sivels, Ciara B.; Suarez, Rey

    2016-01-01

    Silicon detectors are of interest for the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) due to their enhanced energy resolution compared to plastic scintillators beta cells. Previous work developing a figure-of-merit (FOM) for comparison of beta cells suggests that the minimum detectable activity (MDA) could be reduced by a factor of two to three with the use of silicon detectors. Silicon beta cells have been developed by CEA (France) and Lares Ltd. (Russia), with the PIPSBox developed by CEA being commercially available from Canberra for approximately $35k, but there is still uncertainty about the reproducibility of the capabilities in the field. PNNL is developing a high-resolution beta-gamma detector system in the shallow underground laboratory, which will utilize and characterize the operation of the PIPSBox detector. Throughout this report, we examine the capabilities of the PIPSBox as developed by CEA. The lessons learned through the testing and use of the PIPSBox will allow PNNL to strategically develop a silicon detector optimized to better suit the communities needs in the future.

  14. Preventive effects of garlic (Allium sativum) on oxidative stress and histopathology of cardiac tissue in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Naderi, R; Mohaddes, G; Mohammadi, M; Alihemmati, A; Badalzadeh, R; Ghaznavi, R; Ghyasi, R; Mohammadi, Sh

    2015-12-01

    Since some complications of diabetes mellitus may be caused or exacerbated by an oxidative stress, the protective effects of garlic (Allium sativum) were investigated in the blood and heart of streptozotocin-induced diabetic rats. Twenty-eight male Wistar rats were randomly divided into four groups: control, garlic, diabetic, and diabetic+garlic. Diabetes was induced by intraperitoneal (i.p.) injection of streptozotocin (50 mg/kg) in male rats. Rats were fed with raw fresh garlic homogenate (250 mg/kg) six days a week by gavage for a period of 6 weeks. At the end of the 6th week blood samples and heart tissues were collected and used for determination of glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and histological evaluation. Induction of diabetes increased MDA levels in blood and homogenates of heart. In diabetic rats treated with garlic, MDA levels decreased in blood and heart homogenates. Treatment of diabetic rats with garlic increased SOD, GPX and CAT in blood and heart homogenates. Histopathological finding of the myocardial tissue confirmed a protective role for garlic in diabetic rats. Thus, the present study reveals that garlic may effectively modulate antioxidants status in the blood and heart of streptozotocin induced-diabetic rats.

  15. The Hypoglycemic and Antioxidant Activity of Cress Seed and Cinnamon on Streptozotocin Induced Diabetes in Male Rats

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    Safaa Qusti

    2016-01-01

    Full Text Available The present study aimed to estimate the stimulation of pancreas of rats with streptozotocin induced diabetes using 20% (w/w garden cress seed (Lepidium sativum and cinnamon methanol extracts. The positive control diabetic group showed a significant increase in fasting blood sugar, lipid peroxide, interleukin-6, carboxymethyl lysine, serum uric acid, urea, creatinine, immunoglobulins, and urine albumin and a significant decrease in antioxidant enzymes, sodium ions, potassium ions, and urine creatinine. Severe histopathological changes in the kidney and pancreas tissues in hyperglycemic rats were also shown in the positive control diabetic group. Meanwhile, the groups that were treated with 20% garden cress seed and cinnamon methanol extracts showed a significant decrease in fasting blood sugar and all elevated abovementioned biochemical parameters and an increase in the lowered ones restoring them nearly to the normal levels of G1. Kidney and pancreas tissues were also ameliorated and restored nearly to the normal status. Both garden cress seed and cinnamon methanol extracts succeeded in controlling hyperglycemia in rats with streptozotocin induced diabetes and ameliorated the biochemical and histopathological changes because of their antioxidant activity acquired by their possession of phenolic phytochemicals.

  16. Hypolipidemic and hypoglycemic activities of a oleanolic acid derivative from Malva parviflora on streptozotocin-induced diabetic mice.

    Science.gov (United States)

    Gutiérrez, Rosa Martha Pérez

    2017-05-01

    One new oleanolic acid derivative, 2α,3β,23α,29α tetrahydroxyolean-12(13)-en-28-oic acid (1) was isolated from the aerial parts of Malva parviflora. Their structure was characterized by spectroscopic methods. The hypolipidemic and hypoglycemic activities of 1 was analyzed in in streptozotocin (STZ)-nicotinamide-induced type 2 diabetes in mice (MD) and type 1 diabetes in streptozotocin-induced diabetic mice (SD). Triterpene was administered orally at doses of 20 mg/kg for 4 weeks. Organ weight, body weight, glucose, fasting insulin, cholesterol-related lipid profile parameters, glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), serum alkaline phosphatase (SALP), glucokinase, hexokinase, glucose-6-phosphatase activities and glycogen in liver were measured after 4 weeks of treatment. The results indicated that 1 regulate glucose metabolism, lipid profile, lipid peroxidation, increased body weight, glucokinase and hexokinase activities inhibited triglycerides, total cholesterol, low density lipoproteins level, SGOT, SGPT, SALP, glycogen in liver and glucose-6-phosphatase. In addition, improvement of insulin resistance and protective effect for pancreatic β-cells, also 1 may changes the expression of pro-inflammatory cytokine (IL-6 and TNF-α levels) and enzymes (PAL2, COX-2, and LOX). The results suggest that 1 has hypolipidemic and hypoglycemic, anti-inflammatory, activities, improve insulin resistance and hepatic enzymes in streptozotocin-induced diabetic mice.

  17. Antihyperglycaemic activity of the methanol extract from leaves of Eremophila maculata (Scrophulariaceae) in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Youssef, Fadia S; Ashour, Mohamed L; Ebada, Sherif S; Sobeh, Mansour; El-Beshbishy, Hesham A; Singab, Abdel Nasser; Wink, Michael

    2017-06-01

    This study was designed to evaluate the antihyperglycaemic activity of the methanol leaf extract of Eremophila maculata (EMM) both in vitro and in vivo. The antihyperglycaemic activity was assessed in vitro using differentiated 3T3-L1 adipocytes, whereas in-vivo effect was evaluated in streptozotocin-induced diabetic rats. Chemical profiling of EMM was done using LC-ESI-MS techniques. Molecular modelling experiments of the identified compounds were performed using C-Docker protocol. Eremophila maculata slightly enhanced cellular glucose uptake and utilization in vitro by 3.92% relative to the untreated control. A stronger in-vivo effect was observed for EMM and its dichloromethane fraction. A pronounced elevation in serum insulin by 88.89 and 66.67%, respectively, accompanied by an apparent decline in fasting blood glucose (FBG) level by 65.60 and 70.37% comparable to streptozotocin-induced diabetic rats was observed. This effect was stronger than that of the reference drug glibenclamide (GLB). Chemical profiling of EMM revealed that leucoseptoside A, verbascoside, syringaresinol-4-O-β-D-glucopyranoside, pinoresinol-4-O-β-D-glucopyranoside and pinoresinol-4-O-[6″-O-(E)-feruloyl]-β-D-glucopyranoside are the major compounds. Molecular modelling showed that martynoside, verbascoside and phillygenin exhibited the highest inhibition to human pancreatic α-amylase (HPA), maltase glucoamylase (MGAM) and aldose reductase (AR), respectively. Eremophila maculata offers an interesting relatively safer antihyperglycaemic candidate comparable to synthetic analogues. © 2017 Royal Pharmaceutical Society.

  18. In vivo antidiabetic and antioxidant potential of Helichrysum plicatum ssp. plicatum capitulums in streptozotocin-induced-diabetic rats.

    Science.gov (United States)

    Aslan, Mustafa; Deliorman Orhan, Didem; Orhan, Nilüfer; Sezik, Ekrem; Yesilada, Erdem

    2007-01-03

    Helichrysum species (Asteraceae) are widely found in Anatolia. Decoction prepared from the capitulums of Helichrysum plicatum ssp. plicatum is used to alleviate the symptoms of diabetes mellitus in folk medicine. In the present study, the hypoglycaemic and antioxidant potential of Helichrysum plicatum ssp. plicatum was evaluated by using in vivo methods in normal and streptozotocin-induced-diabetic rats. After the oral administration of water and ethanolic extracts at doses of 500mg/kg body weight prepared from the capitulums of plant, blood glucose levels were monitored at specific intervals. Tolbutamide was used as a reference drug at a dose of 100mg/kg. The experimental data indicated that water and ethanol extracts of capitulums demonstrate significant antihyperglycaemic and antioxidant activity in streptozotocin-induced rats which confirmed the folkloric utilization. In order to assess the role of polyphenolic components in the relevant activity, phenolic and flavonoid contents of each extract were also determined in terms of total phenols: 113.5+/-8.6mg (gallic acid equivalent/1g extract) and total flavanoids 50.5+/-1.9mg (quercetin equivalent/1g extract) for ethanol extract, total phenols: 75.9+/-3.7, flavonoids: 31.5+/-2.3 for water extract using Folin-Ciocalteu reagent.

  19. In vitro proliferation of adult human beta-cells.

    Directory of Open Access Journals (Sweden)

    Sabine Rutti

    Full Text Available A decrease in functional beta-cell mass is a key feature of type 2 diabetes. Glucagon-like peptide 1 (GLP-1 analogues induce proliferation of rodent beta-cells. However, the proliferative capacity of human beta-cells and its modulation by GLP-1 analogues remain to be fully investigated. We therefore sought to quantify adult human beta-cell proliferation in vitro and whether this is affected by the GLP-1 analogue liraglutide.Human islets from 7 adult cadaveric organ donors were dispersed into single cells. Beta-cells were purified by FACS. Non-sorted cells and the beta-cell enriched ("beta-cells" population were plated on extracellular matrix from rat (804G and human bladder carcinoma cells (HTB9 or bovine corneal endothelial ECM (BCEC. Cells were maintained in culture+/-liraglutide for 4 days in the presence of BrdU.Rare human beta-cell proliferation could be observed either in the purified beta-cell population (0.051±0.020%; 22 beta-cells proliferating out of 84'283 beta-cells counted or in the non-sorted cell population (0.055±0.011%; 104 proliferating beta-cells out of 232'826 beta-cells counted, independently of the matrix or the culture conditions. Liraglutide increased human beta-cell proliferation on BCEC in the non-sorted cell population (0.082±0.034% proliferating beta-cells vs. 0.017±0.008% in control, p<0.05.These results indicate that adult human beta-cell proliferation can occur in vitro but remains an extremely rare event with these donors and particular culture conditions. Liraglutide increases beta-cell proliferation only in the non-sorted cell population and only on BCEC. However, it cannot be excluded that human beta-cells may proliferate to a greater extent in situ in response to natural stimuli.

  20. Improved function and proliferation of adult human beta cells engrafted in diabetic immunodeficient NOD-scid IL2rγnull mice treated with alogliptin

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    Jurczyk A

    2013-12-01

    Full Text Available Agata Jurczyk,1 Philip diIorio,1 Dean Brostowin,1 Linda Leehy,1 Chaoxing Yang,1 Fumihiko Urano,2 David M Harlan,3 Leonard D Shultz,4 Dale L Greiner,1 Rita Bortell1 1Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 2Department of Medicine, Washington University School of Medicine, St Louis, MO, 3Department of Medicine, University of Massachusetts Medical School, Worcester, MA, 4The Jackson Laboratory, Bar Harbor, ME, USA Purpose: Dipeptidyl-peptidase-4 (DPP-4 inhibitors are known to increase insulin secretion and beta cell proliferation in rodents. To investigate the effects on human beta cells in vivo, we utilize immunodeficient mice transplanted with human islets. The study goal was to determine the efficacy of alogliptin, a DPP-4 inhibitor, to enhance human beta cell function and proliferation in an in vivo context using diabetic immunodeficient mice engrafted with human pancreatic islets. Methods: Streptozotocin-induced diabetic NOD-scid IL2rγnull (NSG mice were transplanted with adult human islets in three separate trials. Transplanted mice were treated daily by gavage with alogliptin (30 mg/kg/day or vehicle control. Islet graft function was compared using glucose tolerance tests and non-fasting plasma levels of human insulin and C-peptide; beta cell proliferation was determined by bromodeoxyuridine (BrdU incorporation. Results: Glucose tolerance tests were significantly improved by alogliptin treatment for mice transplanted with islets from two of the three human islet donors. Islet-engrafted mice treated with alogliptin also had significantly higher plasma levels of human insulin and C-peptide compared to vehicle controls. The percentage of insulin+BrdU+ cells in human islet grafts from alogliptin-treated mice was approximately 10-fold more than from vehicle control mice, consistent with a significant increase in human beta cell proliferation. Conclusion: Human islet-engrafted immunodeficient mice

  1. Evaluation of plasma H2S levels and H2S synthesis in streptozotocin induced Type-2 diabetes-an experimental study based on Swietenia macrophylla seeds

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    Moumita Dutta

    2014-05-01

    Conclusions: Although considering a small sample size, it can conclude that the fasting blood glucose levels are inversely related to plasma H2S levels as well as H2S synthesis activity in plasma and the extract of S. macrophylla is associated with increased plasma H2S levels with effective lowering of blood glucose in streptozotocin induced diabetic rats.

  2. Downregulation of hepatic and intestinal ATP-binding-cassette transporters abcg5 and abcg8 expression associated with altered sterol fluxes in rats with streptozotocin-induced diabetes

    NARCIS (Netherlands)

    Bloks, VW; Bakker-van Waarde, WW; Verkade, HJ; Kema, IP; Havinga, R; Wolters, H; Schaap, FG; Sauer, PJJ; Vink, E; Groen, AK; Kuipers, F

    ABSTRACT: P234 Downregulation of Hepatic and Intestinal ATP-Binding-Cassette Transporters Abcg5 and Abcg8 Expression Associated with Altered Sterol Fluxes in Rats with Streptozotocin-Induced Diabetes Vincent W. Bloks, Willie W. Bakker-van Waarde, Henkjan J. Verkade, Ido P. Kema, Rick Havinga, Henk

  3. Pancreas Protective Effect of Button Mushroom Agaricus bisporus (JE Lange) Imbach (Agaricomycetidae) Extract on Rats with Streptozotocin-Induced Dia betes

    NARCIS (Netherlands)

    Yamac, M.; Kanbak, G.; Zeytinoglu, M.; Senturk, H.; Bayramoglu, G.; Dokumacioglu, A.; Griensven, van L.J.L.D.

    2010-01-01

    In the present study we describe the effects of hot water extract of the culinary-medicinal button mushroom, Agaricus bisporus, on the symptoms of streptozotocin-induced diabetes in Sprague Dawley rats. A. bisporus extract at the doses of 0, 100, 200, and 400 mg/kg body weight (bw) per day were

  4. Modulatory effect of fenugreek seed mucilage and spent turmeric on intestinal and renal disaccharidases in streptozotocin induced diabetic rats.

    Science.gov (United States)

    Kumar, G Suresh; Shetty, A K; Salimath, P V

    2005-06-01

    To elucidate the effect of feeding fenugreek seed mucilage and spent turmeric (10%) on disaccharidases activities, the specific activities of intestinal and renal disaccharidases viz., sucrase, maltase and lactase were measured in streptozotocin induced diabetic rats. Specific activities of intestinal disaccharidases were increased significantly during diabetes and amelioration of these activities during diabetes was clearly visible by supplementing fenugreek seed mucilage and spent turmeric in the diet. However during diabetes renal disaccharidases activities were significantly lower than those in the control rats. Fenugreek seed mucilage and spent turmeric supplementations were beneficial in alleviating the reduction in maltase activity during diabetes, however not much change in the activities of sucrase and lactase was observed upon feeding. This positive influence of feeding fenugreek seed mucilage and spent turmeric on intestinal and renal disaccharidases clearly indicates their beneficial role in the management of diabetes.

  5. Use of unripe plantain (Musa paradisiaca) in the management of diabetes and hepatic dysfunction in streptozotocin induced diabetes in rats.

    Science.gov (United States)

    Eleazu, Chinedum O; Okafor, Polycarp

    2015-03-01

    This study aims to investigate the effect of unripe plantain (Musa paradisiaca) on markers of hepatic dysfunction in streptozotocin induced diabetic rats. Blood glucose; relative liver weight (RLW); relative kidney weight (RKW); relative heart weight (RHW); relative pancreatic weight (RPW); serum and hepatic serum aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP); serum amylase, lipase, total, and conjugated bilirubin; and chemical analysis of the test feed were determined using standard techniques. The diabetic rats had significant alteration (P 0.05) in the RHW of the rats in the three groups, as well as significant decreases (P 0.05) in the amylase levels of the rats fed unripe plantain compared with the nondiabetic rats. The test and standard rat feeds contained considerable amount of proteins, carbohydrates, fats, phenols, and crude fiber. Amelioration of acute pancreatitis by unripe plantain could play a key role in its management of diabetes and related complications.

  6. Enhanced synthesis and secretion of apolipoprotein E from sciatic nerves of streptozotocin-induced diabetic rats after injury

    International Nuclear Information System (INIS)

    Ishibashi, S.; Yamada, N.; Oka, Y.

    1988-01-01

    To elucidate the pathogenesis of diabetic neuropathy, synthesis and secretion of apolipoprotein E (apo E) from sciatic nerves after injury was studied in normal and streptozotocin-induced diabetic rats. Seven, 14, 28, 45 and 59 days after making crush injury on sciatic nerves with concomitant administration of streptozotocin (50 mg/kg body weight), the nerves were taken out and incubated with [ 35 S]methionine. The [ 35 S]labeled apo E was precipitated with specific antiserum. The amounts of apo E secreted into medium by nerves of diabetic rats were 7 times greater than those of non-diabetic rats 7 days after injury. This enhanced secretion of apo E was relatively selective for this protein, since the ratio of the immunoprecipitable apo E to the TCA preciptitable protein in the medium increased in diabetic rats. Intriguing possibility deduced from these results is that the secretion of apo E is involved in the development of diabetic neuropathy

  7. Chronic antidiabetic sulfonylureas in vivo: reversible effects on mouse pancreatic beta-cells.

    Directory of Open Access Journals (Sweden)

    Maria Sara Remedi

    2008-10-01

    chronic glibenclamide treatment in vivo causes loss of insulin secretory capacity due to beta-cell hyperexcitability, but also reveal rapid reversibility of this secretory failure, arguing against beta-cell apoptosis or other cell death induced by sulfonylureas. These in vivo studies may help to explain why patients with type 2 diabetes can show long-term secondary failure to secrete insulin in response to sulfonylureas, but experience restoration of insulin secretion after a drug resting period, without permanent damage to beta-cells. This finding suggests that novel treatment regimens may succeed in prolonging pharmacological therapies in susceptible individuals.

  8. Effects of Icariside II on Corpus Cavernosum and Major Pelvic Ganglion Neuropathy in Streptozotocin-Induced Diabetic Rats

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    Guang-Yi Bai

    2014-12-01

    Full Text Available Diabetic erectile dysfunction is associated with penile dorsal nerve bundle neuropathy in the corpus cavernosum and the mechanism is not well understood. We investigated the neuropathy changes in the corpus cavernosum of rats with streptozotocin-induced diabetes and the effects of Icariside II (ICA II on improving neuropathy. Thirty-six 8-week-old Sprague-Dawley rats were randomly distributed into normal control group, diabetic group and ICA-II treated group. Diabetes was induced by a one-time intraperitoneal injection of streptozotocin (60 mg/kg. Three days later, the diabetic rats were randomly divided into 2 groups including a saline treated placebo group and an ICA II-treated group (5 mg/kg/day, by intragastric administration daily. Twelve weeks later, erectile function was measured by cavernous nerve electrostimulation with real time intracorporal pressure assessment. The penis was harvested for the histological examination (immunofluorescence and immunohistochemical staining and transmission electron microscopy detecting. Diabetic animals exhibited a decreased density of dorsal nerve bundle in penis. The neurofilament of the dorsal nerve bundle was fragmented in the diabetic rats. There was a decreased expression of nNOS and NGF in the diabetic group. The ICA II group had higher density of dorsal nerve bundle, higher expression of NGF and nNOS in the penis. The pathological change of major pelvic nerve ganglion (including the microstructure by transmission electron microscope and the neurite outgrowth length of major pelvic nerve ganglion tissue cultured in vitro was greatly attenuated in the ICA II-treated group (p < 0.01. ICA II treatment attenuates the diabetes-related impairment of corpus cavernosum and major pelvic ganglion neuropathy in rats with Streptozotocin-Induced Diabetes.

  9. In Vivo Evaluation of the Visual Pathway in Streptozotocin-Induced Diabetes by Diffusion Tensor MRI and Contrast Enhanced MRI.

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    Swarupa Kancherla

    Full Text Available Visual function has been shown to deteriorate prior to the onset of retinopathy in some diabetic patients and experimental animal models. This suggests the involvement of the brain's visual system in the early stages of diabetes. In this study, we tested this hypothesis by examining the integrity of the visual pathway in a diabetic rat model using in vivo multi-modal magnetic resonance imaging (MRI. Ten-week-old Sprague-Dawley rats were divided into an experimental diabetic group by intraperitoneal injection of 65 mg/kg streptozotocin in 0.01 M citric acid, and a sham control group by intraperitoneal injection of citric acid only. One month later, diffusion tensor MRI (DTI was performed to examine the white matter integrity in the brain, followed by chromium-enhanced MRI of retinal integrity and manganese-enhanced MRI of anterograde manganese transport along the visual pathway. Prior to MRI experiments, the streptozotocin-induced diabetic rats showed significantly smaller weight gain and higher blood glucose level than the control rats. DTI revealed significantly lower fractional anisotropy and higher radial diffusivity in the prechiasmatic optic nerve of the diabetic rats compared to the control rats. No apparent difference was observed in the axial diffusivity of the optic nerve, the chromium enhancement in the retina, or the manganese enhancement in the lateral geniculate nucleus and superior colliculus between groups. Our results suggest that streptozotocin-induced diabetes leads to early injury in the optic nerve when no substantial change in retinal integrity or anterograde transport along the visual pathways was observed in MRI using contrast agent enhancement. DTI may be a useful tool for detecting and monitoring early pathophysiological changes in the visual system of experimental diabetes non-invasively.

  10. Hypoglycemic action of vitamin K1 protects against early-onset diabetic nephropathy in streptozotocin-induced rats.

    Science.gov (United States)

    Sai Varsha, M K N; Raman, Thiagarajan; Manikandan, R; Dhanasekaran, G

    2015-10-01

    Vitamin K is a potent regulator of vascular dynamics and prevents vascular calcification. Vitamin K is increasingly being recognized for its antioxidant and antiinflammatory properties. Recently we demonstrated that vitamin K1 (5 mg/kg) protects against streptozotocin-induced type 1 diabetes and diabetic cataract. The aim of this study was to determine whether the hypoglycemic action of vitamin K1 could inhibit early-onset diabetic nephropathy in a streptozotocin-induced rat kidney. Male Wistar rats were administered with 35 mg/kg STZ and after 3 days were treated with vitamin K1 (5 mg/kg, twice a week) for 3 months. Blood glucose was monitored once a month. At the end of the study, animals were sacrificed and kidney was dissected out and analysed for free radicals, antioxidants, aldose reductase, membrane ATPases, histopathology evaluation and expression of pro- and anti-inflammatory cytokines. Urea, uric acid, creatinine, albumin and insulin levels were also estimated. Treatment of diabetic rats with vitamin K1 resulted in a decrease in blood glucose and prevented microalbuminuria. Vitamin K1 also reduced oxidative stress and protected renal physiology by modulating Ca(2+) and Na(+)/K(+)-ATPases. Vitamin K1 inhibited renal inflammation by reducing nuclear factor-κB and inducible nitric oxide synthase. Interleukin-10 levels were increased in renal tissues, suggesting the ability of vitamin K1 to trigger antiinflammatory state. The hypoglycemic action of vitamin K1 could have an indirect effect by inhibiting early-onset diabetic nephropathy triggered by high blood glucose. Vitamin K1 could be an important nutrient based interventional strategy for early onset diabetic nephropathy. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Hypoglycemic and beta cell protective effects of andrographolide analogue for diabetes treatment

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    Larrick James W

    2009-07-01

    Full Text Available Abstract Background While all anti-diabetic agents can decrease blood glucose level directly or indirectly, few are able to protect and preserve both pancreatic beta cell mass and their insulin-secreting functions. Thus, there is an urgent need to find an agent or combination of agents that can lower blood glucose and preserve pancreatic beta cells at the same time. Herein, we report a dual-functional andrographolide-lipoic acid conjugate (AL-1. The anti-diabetic and beta cell protective activities of this novel andrographolide-lipoic acid conjugate were investigated. Methods In alloxan-treated mice (a model of type 1 diabetes, drugs were administered orally once daily for 6 days post-alloxan treatment. Fasting blood glucose and serum insulin were determined. Pathologic and immunohistochemical analysis of pancreatic islets were performed. Translocation of glucose transporter subtype 4 in soleus muscle was detected by western blot. In RIN-m cells in vitro, the effect of AL-1 on H2O2-induced damage and reactive oxidative species production stimulated by high glucose and glibenclamide were measured. Inhibition of nuclear factor kappa B (NF-κB activation induced by IL-1β and IFN-γ was investigated. Results In alloxan-induced diabetic mouse model, AL-1 lowered blood glucose, increased insulin and prevented loss of beta cells and their dysfunction, stimulated glucose transport protein subtype 4 (GLUT4 membrane translocation in soleus muscles. Pretreatment of RIN-m cells with AL-1 prevented H2O2-induced cellular damage, quenched glucose and glibenclamide-stimulated reactive oxidative species production, and inhibited cytokine-stimulated NF-κB activation. Conclusion We have demonstrated that AL-1 had both hypoglycemic and beta cell protective effects which translated into antioxidant and NF-κB inhibitory activity. AL-1 is a potential new anti-diabetic agent.

  12. Antidiabetic effects of Cuscuta reflexa Roxb. in streptozotocin induced diabetic rats.

    Science.gov (United States)

    Rath, Diptirani; Kar, Durga Madhab; Panigrahi, Sandeep Kumar; Maharana, Laxmidhar

    2016-11-04

    Cuscuta reflexa Roxb. (Convolvulaceae) is traditionally used to treat diabetes mellitus by tribal people of north-east India and Bangladesh. To evaluate the anti-diabetic effects of methanol and aqueous extracts of the aerial parts of Cuscuta reflexa Roxb. in normal, glucose loaded and Streptozotocin (STZ) induced diabetic rats. The methanol (MECR) and aqueous (AECR) extracts (200 and 400mg/kg body weight) were administered orally to normal and diabetic rats with Metformin and solvent control as comparison groups. Long term effects like FBG, OGTT, lipid profile, HbA1c, body weight, histopathology of major organs, etc. were investigated. MECR and AECR did not have hypoglycemic effects in normal rats. Both AECR and MECR (400mg/kg) treatments showed significant reduction in blood glucose during OGTT in diabetic rats at 3h. Single oral administration of methanol and aqueous extracts (400mg/kg) to diabetic rats significantly reduced (p<0.05) blood glucose level to 61.90% and 55.39% respectively as compared to the Metformin group i.e. 68.32% at the end of 8h. MECR (400mg/kg body weight for 30 days to diabetic rats) showed a significant decrease (p<0.01) of blood glucose level to 60.00% as compared to other groups. The treatment also resulted an improvement in body weights, decreased HbA1c and restored lipid profile. Histopathological injury was not observed, rather repair of beta cells was seen in extract treated diabetic rats. Methanolic extract of C. reflexa has significant antidiabetic effects and improves metabolic alterations thereby justifying its traditional folkloric claims. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Proliferation of sorted human and rat beta cells

    DEFF Research Database (Denmark)

    Parnaud, G; Bosco, D; Berney, T

    2008-01-01

    The aim of the study was to determine whether purified beta cells can replicate in vitro and whether this is enhanced by extracellular matrix (ECM) and growth factors.......The aim of the study was to determine whether purified beta cells can replicate in vitro and whether this is enhanced by extracellular matrix (ECM) and growth factors....

  14. The islet beta-cell: fuel responsive and vulnerable.

    Science.gov (United States)

    Nolan, Christopher J; Prentki, Marc

    2008-10-01

    The pancreatic beta-cell senses blood nutrient levels and is modulated by neurohormonal signals so that it secretes insulin according to the need of the organism. Nutrient sensing involves marked metabolic activation, resulting in the production of coupling signals that promote insulin biosynthesis and secretion. The beta-cell's high capacity for nutrient sensing, however, necessitates reduced protection to nutrient toxicity. This potentially explains why in susceptible individuals, chronic fuel surfeit results in beta-cell failure and type 2 diabetes. Here we discuss recent insights into first, the biochemical basis of beta-cell signaling in response to glucose, amino acids and fatty acids, and second, beta-cell nutrient detoxification. We emphasize the emerging role of glycerolipid/fatty acid cycling in these processes.

  15. Progress in molecular nuclear medicine imaging of pancreatic beta cells

    International Nuclear Information System (INIS)

    Wu Haifei; Yin Hongyan; Liu Shuai; Zhang Yifan

    2010-01-01

    Diabetes mellitus is a common and frequently occurring disease which seriously threaten the health of human beings. Type 1 and type 2 diabetes respectively results from being destroyed and insufficient beta-cell mass. The associated symptoms appear until 50%-60% decrease of beta-cell mass. Because pancreas is deeply located in the body, with few beta-cell mass, the current methods of clinical diagnosis are invasive and late. So diagnosis of metabolism disease of beta-cell early non-invasively becomes more and more popular, imaging diagnosis of diabetes mellitus becomes the focus of researches, but how to estimate the mass of beta-cell still an important subject in imaging technology. (authors)

  16. Chronology of endocrine differentiation and beta-cell neogenesis.

    Science.gov (United States)

    Miyatsuka, Takeshi

    2016-01-01

    Diabetes is a chronic and incurable disease, which results from absolute or relative insulin insufficiency. Therefore, pancreatic beta cells, which are the only type of cell that expresses insulin, is considered to be a potential target for the cure of diabetes. Although the findings regarding beta-cell neogenesis during pancreas development have been exploited to induce insulin-producing cells from non-beta cells, there are still many hurdles towards generating fully functional beta cells that can produce high levels of insulin and respond to physiological signals. To overcome these problems, a solid understanding of pancreas development and beta-cell formation is required, and several mouse models have been developed to reveal the unique features of each endocrine cell type at distinct developmental time points. Here I review our understanding of pancreas development and endocrine differentiation focusing on recent progresses in improving temporal cell labeling in vivo.

  17. Cocoa Phenolic Extract Protects Pancreatic Beta Cells against Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Laura Bravo

    2013-07-01

    Full Text Available Diabetes mellitus is associated with reductions in glutathione, supporting the critical role of oxidative stress in its pathogenesis. Antioxidant food components such as flavonoids have a protective role against oxidative stress-induced degenerative and age-related diseases. Flavonoids constitute an important part of the human diet; they can be found in most plant foods, including green tea, grapes or cocoa and possess multiple biological activities. This study investigates the chemo-protective effect of a cocoa phenolic extract (CPE containing mainly flavonoids against oxidative stress induced by tert-butylhydroperoxide (t-BOOH on Ins-1E pancreatic beta cells. Cell viability and oxidative status were evaluated. Ins-1E cells treatment with 5–20 μg/mL CPE for 20 h evoked no cell damage and did not alter ROS production. Addition of 50 μM t-BOOH for 2 h increased ROS and carbonyl groups content and decreased reduced glutathione level. Pre-treatment of cells with CPE significantly prevented the t-BOOH-induced ROS and carbonyl groups and returned antioxidant defences to adequate levels. Thus, Ins-1E cells treated with CPE showed a remarkable recovery of cell viability damaged by t-BOOH, indicating that integrity of surviving machineries in the CPE-treated cells was notably protected against the oxidative insult.

  18. Transgenic overexpression of active calcineurin in beta-cells results in decreased beta-cell mass and hyperglycemia.

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    Ernesto Bernal-Mizrachi

    2010-08-01

    Full Text Available Glucose modulates beta-cell mass and function through an initial depolarization and Ca(2+ influx, which then triggers a number of growth regulating signaling pathways. One of the most important downstream effectors in Ca(2+ signaling is the calcium/Calmodulin activated serine threonine phosphatase, calcineurin. Recent evidence suggests that calcineurin/NFAT is essential for beta-cell proliferation, and that in its absence loss of beta-cells results in diabetes. We hypothesized that in contrast, activation of calcineurin might result in expansion of beta-cell mass and resistance to diabetes.To determine the role of activation of calcineurin signaling in the regulation of pancreatic beta-cell mass and proliferation, we created mice that expressed a constitutively active form of calcineurin under the insulin gene promoter (caCn(RIP. To our surprise, these mice exhibited glucose intolerance. In vitro studies demonstrated that while the second phase of Insulin secretion is enhanced, the overall insulin secretory response was conserved. Islet morphometric studies demonstrated decreased beta-cell mass suggesting that this was a major component responsible for altered Insulin secretion and glucose intolerance in caCn(RIP mice. The reduced beta-cell mass was accompanied by decreased proliferation and enhanced apoptosis.Our studies identify calcineurin as an important factor in controlling glucose homeostasis and indicate that chronic depolarization leading to increased calcineurin activity may contribute, along with other genetic and environmental factors, to beta-cell dysfunction and diabetes.

  19. Protective Effect of Free and Bound Polyphenol Extracts from Ginger (Zingiber officinale Roscoe) on the Hepatic Antioxidant and Some Carbohydrate Metabolizing Enzymes of Streptozotocin-Induced Diabetic Rats.

    Science.gov (United States)

    Kazeem, Mutiu Idowu; Akanji, Musbau Adewunmi; Yakubu, Musa Toyin; Ashafa, Anofi Omotayo Tom

    2013-01-01

    This study investigated the hepatoprotective effects of polyphenols from Zingiber officinale on streptozotocin-induced diabetic rats by assessing liver antioxidant enzymes, carbohydrate-metabolizing enzymes and liver function indices. Initial oral glucose tolerance test was conducted using 125 mg/kg, 250 mg/kg, and 500 mg/kg body weight of both free and bound polyphenols from Z. officinale. 28 day daily oral administration of 500 mg/kg body weight of free and bound polyphenols from Z. officinale to streptozotocin-induced (50 mg/kg) diabetic rats significantly reduced (P officinale especially the free polyphenol could ameliorate liver disorders caused by diabetes mellitus in rats. This further validates the use of this species as medicinal herb and spice by the larger population of Nigerians.

  20. Differential gene expression in liver tissues of streptozotocin-induced diabetic rats in response to resveratrol treatment.

    Directory of Open Access Journals (Sweden)

    Gökhan Sadi

    Full Text Available This study was conducted to elucidate the genome-wide gene expression profile in streptozotocin induced diabetic rat liver tissues in response to resveratrol treatment and to establish differentially expressed transcription regulation networks with microarray technology. In addition to measure the expression levels of several antioxidant and detoxification genes, real-time quantitative polymerase chain reaction (qRT-PCR was also used to verify the microarray results. Moreover, gene and protein expressions as well as enzymatic activities of main antioxidant enzymes; superoxide dismutase (SOD-1 and SOD-2 and glutathione S-transferase (GST-Mu were analyzed. Diabetes altered 273 genes significantly and 90 of which were categorized functionally which suggested that genes in cellular catalytic activities, oxidation-reduction reactions, co-enzyme binding and terpenoid biosynthesis were dominated by up-regulated expression in diabetes. Whereas; genes responsible from cellular carbohydrate metabolism, regulation of transcription, cell signal transduction, calcium independent cell-to-cell adhesion and lipid catabolism were down-regulated. Resveratrol increased the expression of 186 and decreased the expression of 494 genes in control groups. While cellular and extracellular components, positive regulation of biological processes, biological response to stress and biotic stimulants, and immune response genes were up-regulated, genes responsible from proteins present in nucleus and nucleolus were mainly down-regulated. The enzyme assays showed a significant decrease in diabetic SOD-1 and GST-Mu activities. The qRT-PCR and Western-blot results demonstrated that decrease in activity is regulated at gene expression level as both mRNA and protein expressions were also suppressed. Resveratrol treatment normalized the GST activities towards the control values reflecting a post-translational effect. As a conclusion, global gene expression in the liver tissues is

  1. Protective Effect of Free and Bound Polyphenol Extracts from Ginger (Zingiber officinale Roscoe) on the Hepatic Antioxidant and Some Carbohydrate Metabolizing Enzymes of Streptozotocin-Induced Diabetic Rats

    OpenAIRE

    Kazeem, Mutiu Idowu; Akanji, Musbau Adewunmi; Yakubu, Musa Toyin; Ashafa, Anofi Omotayo Tom

    2013-01-01

    This study investigated the hepatoprotective effects of polyphenols from Zingiber officinale on streptozotocin-induced diabetic rats by assessing liver antioxidant enzymes, carbohydrate-metabolizing enzymes and liver function indices. Initial oral glucose tolerance test was conducted using 125?mg/kg, 250?mg/kg, and 500?mg/kg body weight of both free and bound polyphenols from Z. officinale. 28 day daily oral administration of 500?mg/kg body weight of free and bound polyphenols from Z. officin...

  2. The protective effect of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes

    OpenAIRE

    Mohamed, Jamaludin; Shing, Saw Wuan; Idris, Muhd Hanis Md; Budin, Siti Balkis; Zainalabidin, Satirah

    2013-01-01

    OBJECTIVES: The aim of this study was to investigate the protective effects of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell (RBC) membrane oxidative stress in rats with streptozotocin-induced diabetes. METHODS: Forty male Sprague-Dawley rats weighing 230-250 g were randomly divided into four groups (n = 10 rats each): control group (N), roselle-treated control group, diabetic group, and roselle-treated diabetic group. Roselle was administered by force-f...

  3. Antihyperglycemic effects of separate and composite extract of root of Musa paradisiaca and leaf of Coccinia indica in streptozotocin-induced diabetic male albino rat.

    Science.gov (United States)

    Mallick, Chhanda; Chatterjee, Kausik; Guhabiswas, Mehuli; Ghosh, Debidas

    2007-02-16

    We evaluated the antihyperglycaemic properties of aqueous-methanolic (40:60) extract of root of Musa paradisiaca and leaf of Coccinia indica in separate as well as in composite manner by conducting experiment on streptozotocin-induced diabetic rats. We measured food and water intake ability, the fasting blood glucose level, glucose tolerance, activities of important carbohydrate metabolic enzymes like glucose-6-phosphatase, glucose-6-phosphate dehydrogenase, hexokinase in liver along with quantification of glycogen in liver and in skeletal muscle and serum insulin level. We noted that after treatment of aqueous methanolic extract of above plant parts in separate as well as in composite manner at a concentration of 80 mg/100 g body weight/day to streptozotocin-induced diabetic rat resulted in a significant remedial effect on blood glucose level as well as carbohydrate metabolic enzymes and the quantity of liver and skeletal muscle glycogen. Serum insulin level that was diminished in streptozotocin-induced diabetic rat recovered significantly after the co-administration of extract of above plant parts. All the above parameters showed a more potent remedial effect after composite extract treatment with respect to separate treatment and none of the extract has any general metabolic toxicity induction.

  4. Thioredoxin-1 overexpression in transgenic mice attenuates streptozotocin-induced diabetic osteopenia: a novel role of oxidative stress and therapeutic implications.

    Science.gov (United States)

    Hamada, Yasuhiro; Fujii, Hideki; Kitazawa, Riko; Yodoi, Junji; Kitazawa, Sohei; Fukagawa, Masafumi

    2009-05-01

    Diabetes mellitus is associated with increased risk of osteopenia and bone fracture. However, the mechanisms accounting for diabetic bone disorder are unclear. We have previously reported that streptozotocin-induced diabetic mice develop low turnover osteopenia associated with increased oxidative stress in the diabetic condition. To determine the role of oxidative stress in the development of diabetic osteopenia, we presently investigated the effect of overexpression of thioredoxin-1 (TRX), a major intracellular antioxidant, on the development of diabetic osteopenia, using TRX transgenic mice (TRX-Tg). TRX-Tg are C57BL/6 mice that carry the human TRX transgene under the control of beta-actin promoter. Eight-week-old male TRX-Tg mice and wild type (WT) littermates were intraperitoneally injected with either streptozotocin or vehicle. Mice were grouped as 1) non-diabetic WT, 2) non-diabetic TRX-Tg, 3) diabetic WT, and 4) diabetic TRX-Tg. After 12 weeks of streptozotocin treatment, oxidative stress on the whole body and bone was evaluated, and the physical properties of the femora, and histomorphometry parameters of the tibiae were assessed. TRX overexpression did not affect either body weight or hemoglobin A1c levels. There were no significant differences in renal function and in serum levels of calcium, phosphate, and intact parathyroid hormone among the four groups. On the other hand, urinary excretion of 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative DNA damage, was significantly elevated in diabetic WT and attenuated in diabetic TRX-Tg. Immunohistochemical staining for 8-OHdG revealed marked intensity in the bone tissue of diabetic WT compared with non-diabetic WT, while staining was attenuated in diabetic TRX-Tg. TRX overexpression partially restored reduced bone mineral density and prevented the suppression of bone formation observed in diabetic WT. Increased oxidative stress in diabetic condition contributes to the development of diabetic osteopenia

  5. Resveratrol, a red wine antioxidant, possesses an insulin-like effect in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Su, Hui-Chen; Hung, Li-Man; Chen, Jan-Kan

    2006-06-01

    Aberrant energy metabolism is one characteristic of diabetes mellitus (DM). Two types of DM have been identified, type 1 and type 2. Most of type 2 DM patients eventually become insulin dependent because insulin secretion by the islets of Langerhans becomes exhausted. In the present study, we show that resveratrol (3,5,4'-trihydroxylstilbene) possesses hypoglycemic and hypolipidemic effects in streptozotocin-induced DM (STZ-DM) rats. In resveratrol-treated STZ-DM rats, the plasma glucose concentration on day 14 was reduced by 25.3 +/- 4.2%, and the triglyceride concentration was reduced by 50.2 +/- 3.2% compared with the vehicle-treated rats. In STZ-nicotinamide DM rats, the plasma glucose concentration on day 14 was reduced by 20.3 +/- 4.2%, and the triglyceride concentration was reduced by 33.3 +/- 2.2% compared with the vehicle-treated rats. Resveratrol administration ameliorates common DM symptoms, such as body weight loss, polyphagia, and polydipsia. In STZ-nicotinamide DM rats, resveratrol administration significantly decreased insulin secretion and delayed the onset of insulin resistance. Further studies showed that glucose uptake by hepatocytes, adipocytes, and skeletal muscle and hepatic glycogen synthesis were all stimulated by resveratrol treatment. Because the stimulation of glucose uptake was not attenuated in the presence of an optimal amount of insulin in insulin-responsive cells, the antihyperglycemic effect of resveratrol appeared to act through a mechanism(s) different from that of insulin.

  6. Attenuation of nonenzymatic glycation, hyperglycemia, and hyperlipidemia in streptozotocin-induced diabetic rats by chloroform leaf extract of Azadirachta indica

    Science.gov (United States)

    Gutierrez, Rosa Martha Pérez; Gómez, Yolanda Gómez Y.; Guzman, Mónica Damián

    2011-01-01

    Background: The hypoglycemic effects of hexane, chloroform and methanol extracts of leaves of Azadirachta indica (AI) were evaluated by oral administration in streptozotocin-induced severe diabetic rats (SD). Materials and Methods: The effect of chronic oral administration of the extract for 28 days was evaluated in streptozotozin diabetic rats. Lipid peroxidation, glycogen content of liver and skeletal muscles, insulin, superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), oxidized glutathione (GSSG) levels were determined. In addition, advanced glycation end product formation (AGEs) was evaluated. Results: The most active extracts were obtained with chloroform. Chloroform extract from AI shows increased levels of SOD, GSH, GSSG and CAT, hepatic glycogen content, glucose-6-phosphatase and insulin plasma levels, which also decreased the glucokinase (GK), lipid peroxidation and insulin resistance. The chloroform extract exhibited significant inhibitory activity against advanced glycation end product formation with an IC50 average range of 79.1 mg/ml. Conclusion: Azadirachta indica can improve hyperlipidemia and hyperinsulinema in streptozocin-induced diabetic rats and, therefore, AI can be potentially considered to be an antidiabetic-safe agent. PMID:21969798

  7. Evaluation of toxicity after one-months treatment with Bauhinia forficata decoction in streptozotocin-induced diabetic rats

    Science.gov (United States)

    Pepato, Maria Teresa; Baviera, Amanda Martins; Vendramini, Regina Célia; Brunetti, Iguatemy Lourenço

    2004-01-01

    Background Previous experiments have shown that a decoction of Bauhinia forficata leaves reduces the changes in carbohydrate and protein metabolism that occur in rats with streptozotocin-induced diabetes. In the present investigation, the serum activities of enzymes known to be reliable toxicity markers were monitored in normal and streptozotocin-diabetic rats to discover whether the use of B. forficata decoction has toxic effects on liver, muscle or pancreas tissue or on renal microcirculation. Methods An experimental group of normal and streptozotocin-diabetic rats received an aqueous decoction of fresh B. forficata leaves (150 g/L) by mouth for 33 days while a control group of normal and diabetic rats received water for the same length of time. The serum activity of the toxicity markers lactate dehydrogenase, creatine kinase, amylase, angiotensin-converting enzyme and bilirubin were assayed before receiving B. forficata decoction and on day 19 and 33 of treatment. Results The toxicity markers in normal and diabetic rats were not altered by the diabetes itself nor by treatment with decoction. Whether or not they received B. forficata decoction the normal rats showed a significant increase in serum amylase activity during the experimental period while there was a tendency for the diabetic rats, both treated and untreated with decoction, to have lower serum amylase activities than the normal rats. Conclusions Administration of an aqueous decoction of B. forficata is a potential treatment for diabetes and does not produce toxic effects measurable with the enzyme markers used in our study. PMID:15186500

  8. Potent antihyperglycemic and hypoglycemic effect of Tamarix articulata Vahl. in normal and streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Hebi, Morad; Farid, Omra; Ajebli, Mohammed; Eddouks, Mohamed

    2017-03-01

    The purpose of this study was to investigate the effect of a single dose and daily oral administration for seven days of the aerial part aqueous extract (A.P.A.E) of Tamarix articulata Vahl. (T. articulata) (5mg/kg) on blood glucose levels in both normal and streptozotocin-induced diabetic rats (STZ). Single oral administration of T. articulata A.P.A.E reduced blood glucose levels 6h after administration in normal rats (pTamarix articulata was evaluated by the method of trapping of free radical 2,2-diphenyl-1 picrylhydrazyl (DPPH). Tamarix articulata revealed inhibitory concentrations of 50% of free radicals (IC50) of 203.15μg/ml. In contrast, the synthetic antioxidant butylhydroxytoluene (BHT) has showed an IC50 equal to 13.71μg/ml. In conclusion, this study demonstrates antihyperglycemic, hypoglycemic and antioxidant effects of T. articulata in severe diabetic state thus warrants further investigation on its major compounds as well as mechanistic studies. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  9. Evaluation of antihyperglycaemic activity of Calotropis procera leaves extract on streptozotocin-induced diabetes in Wistar rats

    Directory of Open Access Journals (Sweden)

    Mário C. L. Neto

    Full Text Available Calotropis procera (Aiton W.T.Aiton,Apocynaceae, popularly known as "algodão-de-seda", is a wild African bush, rich in bioactive substances that determine the medicinal potential of this species. Diabetes mellitus is a disease that affects about 10% of the population. This study aimed to evaluate the antihyperglycaemic activity of the hydroalcoholic extract of the leaves of C. procera of occurrence in coast of Pernambuco, Brazil. The hydroalcholic extract of the leaves of C. procera (300 and 600 mg/kg/day, vehicle, insulin (6U, s.c. or metformin (500 mg/ kg/day were administered orally to streptozotocin-induced diabetic rats (n = 7/group for four weeks. Changes in body weight, food and water intake, biochemical markers, fasting glucose levels and oral glucose tolerance test were evaluated. The results showed that the C. procera dried extract (300 and 600 mg/kg reduced significantly the level of blood glucose throughout the evaluation period and improved metabolic status of the animals and ameliorate the oral tolerance glucose test. The phytochemical screening revealed and quantified the presence of phenolic compounds and flavonoids in a percentage of 29.1 and 2.9%, respectively. Thus, we conclude that the extract of the leaves of C. procera has antihyperglycemic activity.

  10. Effects of the aqueous extract of white tea (Camellia sinensis) in a streptozotocin-induced diabetes model of rats.

    Science.gov (United States)

    Islam, Md Shahidul

    2011-12-15

    White tea (WT) is very similar to green tea (GT) but it is exceptionally prepared only from the buds and young tea leaves of Camelia sinensis plant while GT is prepared from the matured tea leaves. The present study was investigated to examine the effects of a 0.5% aqueous extract of WT in a streptozotocin-induced diabetes model of rats. Six-week-old male Sprague-Dawley rats were divided into 3 groups of 6 animals in each group namely: normal control (NC), diabetic control (DBC) and diabetic white tea (DWT). Diabetes was induced by an intraperitoneal injection of streptozotocin (65 mg/kg BW) in DBC and DWT groups except the NC group. After 4 weeks feeding of 0.5% aqueous extracts of WT, the drink intake was significantly (Pfood intake, body weight gain, serum insulin and fructosamine concentrations were not influenced by the consumption of WT. Data of this study suggest that the 0.5% aqueous extract of WT is effective to reduce most of the diabetes associated abnormalities in a steptozotocin-induced diabetes model of rats. Copyright © 2011 Elsevier GmbH. All rights reserved.

  11. The Effect of Aspalathin on Levels of Sugar and Lipids in Streptozotocin-Induced Diabetic and Normal Rats

    Directory of Open Access Journals (Sweden)

    Mahmood Najafian

    2016-10-01

    Full Text Available Background Flavonoids have been reported as mammalian alpha-amylase inhibitors, a property which could be useful in the management of postprandial hyperglycemia in diabetes and its related disorders. Objectives In the present study the inhibitory effect of aspalathin as a flavonoid on alpha amylase activity and levels of sugar and lipids in rats, has been investigated. Methods In this experimental study, type inhibition of aspalatin on amylase and in the part of in vivo, the effect of aspalathin orally doses 5, 10, 20 and 40 mg/kg body weight on sugar and lipids levels was tested in a streptozotocin-induced model of diabetes and normal rats. The data were analyzed by one-sample Kolmogrov-Smirnov, Levene and ANOVA tests through SPSS version 22. Results The results showed that aspalathin is a competitive inhibitor for alpha amylase with Ki = 37.0 μM. In both diabetic and normal groups in all doses nearly dose dependent manner reduced blood glucose levels and beneficial effect on dyslipidemia were observed in diabetic rats, as well as reduction of disturbing consequences of diabetes such as high urine volume and water intake. Aspalathin was observed to have a weight loss-inductive effect, alongside with a reduction in food intake. Conclusions It seems that, this compound could be proposed as an antihyperglycemic and antihyperlipidemic agent in diabetes and potential therapeutic in obesity.

  12. The Antidiabetic Activity of Nigella sativa and Propolis on Streptozotocin-Induced Diabetes and Diabetic Nephropathy in Male Rats

    Directory of Open Access Journals (Sweden)

    Haddad A. El Rabey

    2017-01-01

    Full Text Available This study was conducted to compare the ameliorative effect of Nigella sativa and propolis methanol extract on streptozotocin-induced diabetic male rats and treating diabetic nephropathy. Forty male Albino rats were divided into four groups; the first group was the negative control fed standard diet. The other 30 rats were injected with streptozotocin to induce diabetes by a single intravenous injection and then divided equally into three groups; the second group was the positive diabetic control; the third and the fourth groups were treated orally with 20% w/w Nigella sativa seeds methanol extract and propolis methanol extract (20% w/w, respectively. The rats of the second group showed increased glucose levels and lipid peroxide accompanied with reduction in superoxide dismutase, catalase, and glutathione-S-transferase enzyme activities compared with the negative control. Carboxymethyl lysine, interleukin-6, and immunoglobulins were also increased as a result of diabetes. Kidney function parameters were also elevated, while potassium and sodium levels were decreased. Moreover, tissues of kidney and pancreas showed severe histopathological changes. Treating the diabetic rats with Nigella sativa and propolis methanol extract in the third and fourth groups, respectively, ameliorated all altered biochemical and pathological examinations approaching the negative control. Propolis was more effective than Nigella sativa.

  13. Investigation of the in vivo antioxidative activity of Cynara scolymus (artichoke) leaf extract in the streptozotocin-induced diabetic rat.

    Science.gov (United States)

    Magielse, Joanna; Verlaet, Annelies; Breynaert, Annelies; Keenoy, Begoña Manuel Y; Apers, Sandra; Pieters, Luc; Hermans, Nina

    2014-01-01

    The in vivo antioxidant activity of a quantified leaf extract of Cynara scolymus (artichoke) was studied. The aqueous artichoke leaf extract (ALE), containing 1.5% caffeoylquinic acid with chlorogenic acid being most abundant (0.30%), and luteolin-7-O-glucoside as major flavonoid (0.15%), was investigated by evaluating the effect on different oxidative stress biomarkers, after 3 wk oral supplementation in the streptozotocin-induced diabetic rat model. Apart from two test groups (0.2 g ALE/kg BW/day and 1 g ALE/kg BW/day, where BW is body weight), a healthy control group, untreated oxidative stress group, and vitamin E treated group (positive control) were included. A 0.2 g/kg BW/day of ALE decreased oxidative stress: malondialdehyde and 8-hydroxydeoxyguanosine levels significantly diminished, whereas erythrocyte glutathione levels significantly increased. A 1.0 g/kg BW/day ALE did not show higher antioxidant activity. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Effect of streptozotocin-induced diabetes on myocardial blood flow reserve assessed by myocardial contrast echocardiography in rats

    Directory of Open Access Journals (Sweden)

    Weytjens Caroline

    2008-09-01

    Full Text Available Abstract The role of structural and functional abnormalities of small vessels in diabetes cardiomyopathy remains unclear. Myocardial contrast echocardiography allows the quantification of myocardial blood flow at rest and during dipyridamole infusion. The aim of the study was to determine the myocardial blood flow reserve in normal rats compared with Streptozotocin-induced diabetic rats using contrast echocardiography. Methods We prospectively studied 40 Wistar rats. Diabetes was induced by intravenous streptozotocin in 20 rats. All rats underwent baseline and stress (dipyridamole: 20 mg/kg high power intermittent imaging in short axis view under anaesthesia baseline and after six months. Myocardial blood flow was determined and compared at rest and after dipyridamole in both populations. The myocardial blood flow reserve was calculated and compared in the 2 groups. Parameters of left ventricular function were determined from the M-mode tracings and histological examination was performed in all rats at the end of the study. Results At six months, myocardial blood flow reserve was significantly lower in diabetic rats compared to controls (3.09 ± 0.98 vs. 1.28 ± 0.67 ml min-1 g-1; p Conclusion In this animal study, diabetes induced a functional alteration of the coronary microcirculation, as demonstrated by contrast echocardiography, a decrease in capillary density and of the cardiac systolic function. These findings may offer new insights into the underlying mechanisms of diabetes cardiomyopathy.

  15. High-dose thiamine therapy counters dyslipidemia and advanced glycation of plasma protein in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Karachalias, Nikolaos; Babaei-Jadidi, Roya; Kupich, Christian; Ahmed, Naila; Thornalley, Paul J

    2005-06-01

    The streptozotocin-induced (STZ) diabetic rat experimental model of diabetes on insulin maintenance therapy exhibits dyslipidemia, mild thiamine deficiency, and increased plasma protein advanced glycation end products (AGEs). The reversal of thiamine deficiency by high-dose thiamine and S-benzoylthiamine monophosphate (benfotiamine) prevented the development of incipient nephropathy. Recently, we reported that high-dose thiamine (but not benfotiamine) countered diabetic dyslipidemia. To understand further the differences between the effects of thiamine and benfotiamine therapy, we quantified the levels of the AGEs in plasma protein. We found hydroimidazolone AGE residues derived from glyoxal and methylglyoxal, G-H1 and MG-H1, were increased 115% and 68% in STZ diabetic rats, with respect to normal controls, and were normalized by both thiamine and benfotiamine; whereas N-carboxymethyl-lysine (CML) and N-carboxyethyl-lysine (CEL) residues were increased 74% and 118% in STZ diabetic rats and were normalized by thiamine only. The lack of effect of benfotiamine on plasma CML and CEL residue concentrations suggests there may be important precursors of plasma protein CML and CEL residues other than glyoxal and methylglyoxal. These are probably lipid-derived aldehydes.

  16. A study of antidiabetic and antioxidant effects of Helichrysum graveolens capitulums in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Aslan, Mustafa; Orhan, Didem Deliorman; Orhan, Nilüfer; Sezik, Ekrem; Yeşilada, Erdem

    2007-06-01

    Helichrysum graveolens (Bieb.) Sweet (Asteraceae) grows widely in Turkey. Capitulums of H. graveolens are used in the treatment of many diseases such as jaundice and wound healing and as a diuretic in the rural areas of Anatolia. The decoction from the capitulums of the plant is consumed for the symptoms of diabetes mellitus in folk medicine. In the present study, the hypoglycemic, antihyperglycemic, and antioxidant potentials of water and ethanol extracts of H. graveolens were evaluated by using in vivo methods in normal and streptozotocin-induced diabetic rats. Blood glucose levels of animals were measured by the glucose oxidase method. The antioxidant activity of these extracts was also studied in liver, kidney, and heart tissues. In order to determine antioxidant activity, tissue malondialdehyde and reduced glutathione levels were measured by using spectrophotometric methods. The experimental data obtained from water and ethanol extracts of capitulums confirmed the folkloric utilization. In order to discuss the role of polyphenolic components in the relevant activity, total phenol and flavonoid contents of each extract were also determined using the Folin-Ciocalteu reagent, and a positive correlation was observed.

  17. Niceritrol prevents the decrease in red blood cell 2,3-diphosphoglycerate and neuropathy in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Hotta, N; Nakamura, J; Kakuta, H; Fukasawa, H; Koh, N; Sakakibara, F; Mori, K; Sakamoto, N

    1995-01-01

    Nerve ischemia/hypoxia has been linked to the pathogenesis of diabetic complications. Red blood cell 2,3-diphosphoglycerate is an important regulator of peripheral tissue oxygenation; however, the relationship between 2,3-diphosphoglycerate concentration and diabetic complications has not been studied in detail. This investigation focused on the relationship between red blood cell 2,3-diphosphoglycerate and diabetic neuropathy, by measuring motor nerve conduction velocity and sciatic nerve blood flow in streptozotocin-induced diabetic rats. The effect of treatment with niceritrol, a nicotinic acid derivative that acts as a vasodilator and reduces serum lipid concentrations, on 2,3-diphosphoglycerate concentration and diabetic neuropathy was also examined. Untreated diabetic rats had significantly lower concentrations of red blood cell 2,3-diphosphoglycerate, higher concentrations of serum total cholesterol and triglyceride, as well as reduced motor nerve conduction velocity and sciatic nerve blood flow, compared to untreated normal rats. Niceritrol prevented these abnormalities without correcting hyperglycemia in diabetic rats, but had no effect on these parameters in normal rats. Red blood cell 2,3-diphosphoglycerate concentration and motor nerve conduction velocity showed a positive correlation with sciatic nerve blood flow and 2,3-diphosphoglycerate, respectively. These observations suggest that ischemia/hypoxia plays an important role in the development of diabetic neuropathy, and that niceritrol has a therapeutic effect on this condition by improving endoneurial ischemia/hypoxia.

  18. Antidiabetic and Synergistic Effects of Anthocyanin Fraction from Berberis integerrima Fruit on Streptozotocin-Induced Diabetic Rats Model

    Directory of Open Access Journals (Sweden)

    Zahra Sabahi

    2016-03-01

    Full Text Available Diabetes mellitus is a complex endocrine disorder. There is a serious attempt to identify antidiabetic compounds from natural sources to use with other drugs for reduction of diabetes complications. Present study is based on the investigation of antihyperglycemic effect of anthocyanin fraction of Berberis integerrima Bunge (AFBI fruits on some physiological parameters (glucose level, glycogen content, and body weight in normal and streptozotocin-induced (STZ-induced diabetic rats and evaluation of synergic effect of this fraction with metformin and glibenclamide. Male Sprague dawley rats were divided into nine groups: healthy control group, diabetic control group, diabetic groups treated with anthocyanin fraction (200, 400 and 1000 mg/kg, respectively; diabetic groups treated with glibenclamide and metformin separately, diabetic groups treated with glibenclamide + anthocyanin fraction (1000 mg/kg, metformin + anthocyanin fraction (1000 mg/kg. Treatment of diabetic rats with AFBI (400, 1000mg/kg significantly decreased blood glucose as compared with control. Moreover, AFBI (400, 1000mg/kg significantly increased liver glycogen and body weight compared to control. Nevertheless, there were no synergistic effects between anthocyanin fraction and metformin or glibenclamide on blood glucose, liver glycogen, and body weight. The results of this study indicate that AFBI possesses hypoglycemic effects and may be considered for evaluation in future diabetes clinical studies.

  19. Effect of streptozotocin-induced diabetes on motor representations in the motor cortex and corticospinal tract in rats.

    Science.gov (United States)

    Muramatsu, Ken; Ikutomo, Masako; Tamaki, Toru; Shimo, Satoshi; Niwa, Masatoshi

    2018-02-01

    Motor disorders in patients with diabetes are associated with diabetic peripheral neuropathy, which can lead to symptoms such as lower extremity weakness. However, it is unclear whether central motor system disorders can disrupt motor function in patients with diabetes. In a streptozotocin-induced rat model of type 1 diabetes, we used intracortical microstimulation to evaluate motor representations in the motor cortex, recorded antidromic motor cortex responses to spinal cord stimulation to evaluate the function of corticospinal tract (CST) axons, and used retrograde labeling to evaluate morphological alterations of CST neurons. The diabetic rats exhibited size reductions in the hindlimb area at 4 weeks and in trunk and forelimb areas after 13 weeks, with the hindlimb and trunk area reductions being the most severe. Other areas were unaffected. Additionally, we observed reduced antidromic responses in CST neurons with axons projecting to lumbar spinal segments (CST-L) but not in those with axons projecting to cervical segments (CST-C). This was consistent with the observation that retrograde-labeled CST-L neurons were decreased in number following tracer injection into the spinal cord in diabetic animals but that CST-C neurons were preserved. These results show that diabetes disrupts the CST system components controlling hindlimb and trunk movement. This disruption may contribute to lower extremity weakness in patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Re-exposure to beta cell autoantigens in pancreatic allograft recipients with preexisting beta cell autoantibodies.

    Science.gov (United States)

    Mujtaba, Muhammad Ahmad; Fridell, Jonathan; Book, Benita; Faiz, Sara; Sharfuddin, Asif; Wiebke, Eric; Rigby, Mark; Taber, Tim

    2015-11-01

    Re-exposure to beta cell autoantigens and its relevance in the presence of donor-specific antibodies (DSA) in pancreatic allograft recipients is not well known. Thirty-three patients requiring a pancreas transplant were enrolled in an IRB approved study. They underwent prospective monitoring for DSA and beta cell autoantibody (BCAA) levels to GAD65, insulinoma-associated antigen 2 (IA-2), insulin (micro-IAA [mIAA]), and islet-specific zinc transporter isoform-8 (ZnT8). Twenty-five (75.7%) had pre-transplant BCAA. Twenty had a single antibody (mIAA n = 15, GAD65 n = 5); five had two or more BCAA (GAD65 + mIAA n = 2, GAD65 + mIAA+IA-2 n = 2, GA65 + mIAA+IA-2 + ZnT8 = 1). No changes in GAD65 (p > 0.29), IA-2 (>0.16), and ZnT8 (p > 0.07) were observed between pre-transplant and post-transplant at 6 or 12 months. A decrease in mIAA from pre- to post-6 months (p BCAA was observed at one yr. Seven (21.0%) developed de novo DSA. The incidence of DSA was 24% in patients with BCAA vs. 25% in patients without BCAA (p = 0.69). Pancreatic allograft function of patients with vs. without BCAA, and with and without BCAA + DSA was comparable until last follow-up (three yr). Re-exposure to beta cell autoantigens by pancreas transplant may not lead to increased levels or development of new BCAA or pancreatic allograft dysfunction. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Vorapaxar treatment reduces mesangial expansion in streptozotocin-induced diabetic nephropathy in mice.

    Science.gov (United States)

    Waasdorp, Maaike; Duitman, JanWillem; Florquin, Sandrine; Spek, C Arnold

    2018-04-24

    Twenty years after the onset of diabetes, up to 40% of patients develop diabetic nephropathy. Protease-activated receptor-1 (PAR-1) has recently been shown to aggravate the development of experimental diabetic nephropathy. PAR-1 deficient mice develop less albuminuria and glomerular lesions and PAR-1 stimulation induces proliferation and fibronectin production in mesangial cells in vitro . Vorapaxar is a clinically available PAR-1 inhibitor which is currently used for secondary prevention of ischemic events. The aim of this study was to investigate in a preclinical setting whether vorapaxar treatment may be a novel strategy to reduce diabetes-induced kidney damage. While control treated diabetic mice developed significant albuminuria, mesangial expansion and glomerular fibronectin deposition, diabetic mice on vorapaxar treatment did not show any signs of kidney damage despite having similar levels of hyperglycemia. These data show that PAR-1 inhibition by vorapaxar prevents the development of diabetic nephropathy in this preclinical animal model for type I diabetes and pinpoint PAR-1 as a novel therapeutic target to pursue in the setting of diabetic nephropathy. 22 C57Bl/6 mice were made diabetic using multiple low-dose streptozotocin injections (50 mg/kg) and 22 littermates served as non-diabetic controls. Four weeks after the induction of diabetes, 11 mice of each group were assigned to control or vorapaxar treatment. Mice were sacrificed after 20 weeks of treatment and kidney damage was evaluated.

  2. Neuroprotective effect of ginger in the brain of streptozotocin-induced diabetic rats.

    Science.gov (United States)

    El-Akabawy, Gehan; El-Kholy, Wael

    2014-05-01

    Diabetes mellitus results in neuronal damage caused by increased intracellular glucose leading to oxidative stress. Recent evidence revealed the potential of ginger for reducing diabetes-induced oxidative stress markers. The aim of this study is to investigate, for the first time, whether the antioxidant properties of ginger has beneficial effects on the structural brain damage associated with diabetes. We investigated the observable neurodegenerative changes in the frontal cortex, dentate gyrus, and cerebellum after 4, 6, and 8 weeks of streptozotocin (STZ)-induced diabetes in rats and the effect(s) of ginger (500 mg/kg/day). Sections of frontal cortex, dentate gyrus, and cerebellum were stained with hematoxylin and eosin and examined using light microscopy. In addition, quantitative immunohistochemical assessments of the expression of inducible NO synthase (iNOS), tumor necrosis factor (TNF)-α, caspase-3, glial fibrillary acidic protein (GFAP), acetylcholinesterase (AChE), and Ki67 were performed. Our results revealed a protective role of ginger on the diabetic brain via reducing oxidative stress, apoptosis, and inflammation. In addition, this study revealed that the beneficial effect of ginger was also mediated by modulating the astroglial response to the injury, reducing AChE expression, and improving neurogenesis. These results represent a new insight into the beneficial effects of ginger on the structural alterations of diabetic brain and suggest that ginger might be a potential therapeutic strategy for the treatment of diabetic-induced damage in brain. Copyright © 2014 Elsevier GmbH. All rights reserved.

  3. On the coherent behavior of pancreatic beta cell clusters

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    Loppini, Alessandro, E-mail: a.loppini@unicampus.it [Nonlinear Physics and Mathematical Modeling Lab, University Campus Bio-Medico, Via A. del Portillo 21, I-00128 Rome (Italy); Capolupo, Antonio, E-mail: capolupo@sa.infn.it [Physics Department, University of Salerno, Fisciano, 84084 (Italy); Cherubini, Christian, E-mail: c.cherubini@unicampus.it [Nonlinear Physics and Mathematical Modeling Lab, University Campus Bio-Medico, Via A. del Portillo 21, I-00128 Rome (Italy); International Center for Relativistic Astrophysics, University Campus Bio-Medico, Via A. del Portillo 21, I-00128, Rome (Italy); Gizzi, Alessio, E-mail: a.gizzi@unicampus.it [Nonlinear Physics and Mathematical Modeling Lab, University Campus Bio-Medico, Via A. del Portillo 21, I-00128 Rome (Italy); Bertolaso, Marta, E-mail: m.bertolaso@unicampus.it [Faculty of Engineering and Institute of Philosophy of Scientific and Technological Practice, University Campus Bio-Medico, Via A. del Portillo 21, I-00128 Rome (Italy); Filippi, Simonetta, E-mail: s.filippi@unicampus.it [Nonlinear Physics and Mathematical Modeling Lab, University Campus Bio-Medico, Via A. del Portillo 21, I-00128 Rome (Italy); International Center for Relativistic Astrophysics, University Campus Bio-Medico, Via A. del Portillo 21, I-00128, Rome (Italy); Vitiello, Giuseppe, E-mail: vitiello@sa.infn.it [Physics Department, University of Salerno, Fisciano, 84084 (Italy)

    2014-09-12

    Beta cells in pancreas represent an example of coupled biological oscillators which via communication pathways, are able to synchronize their electrical activity, giving rise to pulsatile insulin release. In this work we numerically analyze scale free self-similarity features of membrane voltage signal power density spectrum, through a stochastic dynamical model for beta cells in the islets of Langerhans fine tuned on mouse experimental data. Adopting the algebraic approach of coherent state formalism, we show how coherent molecular domains can arise from proper functional conditions leading to a parallelism with “phase transition” phenomena of field theory. - Highlights: • Beta cells in pancreas are coupled oscillators able to synchronize their activity. • We analyze scale free self-similarity features for beta cells. • We adopt the algebraic approach of coherent state formalism. • We show that coherent molecular domains arise from functional conditions.

  4. The EndoC-βH1 cell line is a valid model of human beta cells and applicable for screenings to identify novel drug target candidates.

    Science.gov (United States)

    Tsonkova, Violeta Georgieva; Sand, Fredrik Wolfhagen; Wolf, Xenia Asbæk; Grunnet, Lars Groth; Kirstine Ringgaard, Anna; Ingvorsen, Camilla; Winkel, Louise; Kalisz, Mark; Dalgaard, Kevin; Bruun, Christine; Fels, Johannes Josef; Helgstrand, Charlotte; Hastrup, Sven; Öberg, Fredrik Kryh; Vernet, Erik; Sandrini, Michael Paolo Bastner; Shaw, Allan Christian; Jessen, Carsten; Grønborg, Mads; Hald, Jacob; Willenbrock, Hanni; Madsen, Dennis; Wernersson, Rasmus; Hansson, Lena; Jensen, Jan Nygaard; Plesner, Annette; Alanentalo, Tomas; Petersen, Maja Borup Kjær; Grapin-Botton, Anne; Honoré, Christian; Ahnfelt-Rønne, Jonas; Hecksher-Sørensen, Jacob; Ravassard, Philippe; Madsen, Ole D; Rescan, Claude; Frogne, Thomas

    2018-02-01

    To characterize the EndoC-βH1 cell line as a model for human beta cells and evaluate its beta cell functionality, focusing on insulin secretion, proliferation, apoptosis and ER stress, with the objective to assess its potential as a screening platform for identification of novel anti-diabetic drug candidates. EndoC-βH1 was transplanted into mice for validation of in vivo functionality. Insulin secretion was evaluated in cells cultured as monolayer and as pseudoislets, as well as in diabetic mice. Cytokine induced apoptosis, glucolipotoxicity, and ER stress responses were assessed. Beta cell relevant mRNA and protein expression were investigated by qPCR and antibody staining. Hundreds of proteins or peptides were tested for their effect on insulin secretion and proliferation. Transplantation of EndoC-βH1 cells restored normoglycemia in streptozotocin induced diabetic mice. Both in vitro and in vivo, we observed a clear insulin response to glucose, and, in vitro, we found a significant increase in insulin secretion from EndoC-βH1 pseudoislets compared to monolayer cultures for both glucose and incretins. Apoptosis and ER stress were inducible in the cells and caspase 3/7 activity was elevated in response to cytokines, but not affected by the saturated fatty acid palmitate. By screening of various proteins and peptides, we found Bombesin (BB) receptor agonists and Pituitary Adenylate Cyclase-Activating Polypeptides (PACAP) to significantly induce insulin secretion and the proteins SerpinA6, STC1, and APOH to significantly stimulate proliferation. ER stress was readily induced by Tunicamycin and resulted in a reduction of insulin mRNA. Somatostatin (SST) was found to be expressed by 1% of the cells and manipulation of the SST receptors was found to significantly affect insulin secretion. Overall, the EndoC-βH1 cells strongly resemble human islet beta cells in terms of glucose and incretin stimulated insulin secretion capabilities. The cell line has an active

  5. The EndoC-βH1 cell line is a valid model of human beta cells and applicable for screenings to identify novel drug target candidates

    Directory of Open Access Journals (Sweden)

    Violeta Georgieva Tsonkova

    2018-02-01

    Full Text Available Objective: To characterize the EndoC-βH1 cell line as a model for human beta cells and evaluate its beta cell functionality, focusing on insulin secretion, proliferation, apoptosis and ER stress, with the objective to assess its potential as a screening platform for identification of novel anti-diabetic drug candidates. Methods: EndoC-βH1 was transplanted into mice for validation of in vivo functionality. Insulin secretion was evaluated in cells cultured as monolayer and as pseudoislets, as well as in diabetic mice. Cytokine induced apoptosis, glucolipotoxicity, and ER stress responses were assessed. Beta cell relevant mRNA and protein expression were investigated by qPCR and antibody staining. Hundreds of proteins or peptides were tested for their effect on insulin secretion and proliferation. Results: Transplantation of EndoC-βH1 cells restored normoglycemia in streptozotocin induced diabetic mice. Both in vitro and in vivo, we observed a clear insulin response to glucose, and, in vitro, we found a significant increase in insulin secretion from EndoC-βH1 pseudoislets compared to monolayer cultures for both glucose and incretins.Apoptosis and ER stress were inducible in the cells and caspase 3/7 activity was elevated in response to cytokines, but not affected by the saturated fatty acid palmitate.By screening of various proteins and peptides, we found Bombesin (BB receptor agonists and Pituitary Adenylate Cyclase-Activating Polypeptides (PACAP to significantly induce insulin secretion and the proteins SerpinA6, STC1, and APOH to significantly stimulate proliferation.ER stress was readily induced by Tunicamycin and resulted in a reduction of insulin mRNA. Somatostatin (SST was found to be expressed by 1% of the cells and manipulation of the SST receptors was found to significantly affect insulin secretion. Conclusions: Overall, the EndoC-βH1 cells strongly resemble human islet beta cells in terms of glucose and incretin stimulated

  6. d-limonene ameliorates diabetes and its complications in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Bacanlı, Merve; Anlar, Hatice Gül; Aydın, Sevtap; Çal, Tuğbagül; Arı, Nuray; Ündeğer Bucurgat, Ülkü; Başaran, A Ahmet; Başaran, Nurşen

    2017-12-01

    It is known that diabetes causes some complications including alterations in lipid profile, hepatic enzyme levels but also it causes oxidative stress. Limonene, a major component of Citrus oils, has important health beneficial effects in lowering the level of oxidative stress due to its antioxidant activity. The aim of this study was to investigate the effects of D-limonene on streptozotocin (STZ)-induced diabetes in Wistar albino rats. For this purpose, DNA damage was evaluated by alkaline comet assay. Changes in the activities of catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR) and glutathione peroxidase (GSHPx) and the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), total glutathione (GSH), malondialdehyde (MDA), insulin, total bilirubin and BCA protein, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT), high density lipoprotein (HDL), low density lipoprotein (LDL), total cholesterol and triglyceride were also evaluated. D-limonene treatment was found to significantly decrease DNA damage, GR enzyme activities and MDA levels and significantly increase GSH levels and CAT, SOD and GSH-Px enzyme activities and altered lipid and liver enzyme parameters in diabetic rats. According to our results, it seems that D-limonene might have a role in the prevention of the complication of diabetes in rats. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Attenuation of Oxidative Stress and Inflammation by Portulaca oleracea in Streptozotocin-Induced Diabetic Rats.

    Science.gov (United States)

    Samarghandian, Saeed; Borji, Abasalt; Farkhondeh, Tahereh

    2017-10-01

    The present study was designed to investigate the protective effect of the aqueous extract of Portulaca oleracea against hyperglycemic, oxidative damage and inflammation in the serum of streptozotocin (STZ)-induced diabetic rats. In the present study, the rats were divided into the following groups of 8 animals each: control, untreated diabetic, 3 Portulaca oleracea (100, 200, 400 mg/kg/d)-treated diabetic groups. At the end of the 4-week period, glucose, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), malondialdehyde (MDA), glutathione (GSH), and total antioxidant status (TAS) levels were measured. STZ caused an elevation in the serum levels of glucose, MDA, IL-6, and TNF-α with reduction in the levels of GSH and TAS ( P Portulaca oleracea ameliorated glucose, MDA, IL-6, TNF-α, GSH, and TAS levels in diabetic groups versus to the untreated groups ( P Portulaca oleracea prevented hyperglycemia by preventing the oxidative stress and inflammation.

  8. Beneficial effects of an Andrographis paniculata extract and andrographolide on cognitive functions in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Thakur, Ajit Kumar; Rai, Geeta; Chatterjee, Shyam Sunder; Kumar, Vikas

    2016-09-01

    Context Andrographolide containing Andrographis paniculata (Burm. F.) Wall. Ex Nees (Acanthaceae) extracts is often used for treatments of diabetes and other inflammatory disorders commonly accompanying cognitive and other psychiatric disorders. Objective To compare the efficacies of a standardised A. paniculata extract (AP) and pure andrographolide on cognitive functions, oxidative stress and cholinergic function in diabetic rats. Materials and methods Streptozotocin-induced diabetic Charles Foster albino rats treated orally with a hydro-methanolic A. paniculata leaf extract (50, 100 and 200 mg/kg/day), or with pure andrographolide (15, 30 and 60 mg/kg/day) for 10 consecutive days, were subjected to Morris water maze test. After the test, acetylcholinesterase, superoxide dismutase (SOD), and catalase (CAT) activities and lipid peroxidation (LPO) in brain tissues were assessed. Results Acetylcholinesterase activity in pre-frontal cortex and hippocampus of diabetic rats was 2.1 and 2.6 times higher compared to nondiabetic rats. LPO was 1.6 times higher and decreased SOD (56.3%) and CAT (44.9%) activities in pre-frontal cortex of diabetic rats compared to nondiabetic rats. AP or andrographolide treatments dose dependently attenuated cognitive deficits, reduced acetylcholinesterase activity, oxidative stress, improved diabetic hyperglycemia and insulin deficiency. All observed effects of AP were quantitatively almost equal to those expected from its analytically quantified andrographolide content. Discussion and conclusion Reported observations are the very first ones suggesting beneficial effects of andrographolide against diabetes associated cognitive deficits, increased acetylcholinesterase activity and deteriorated antioxidative status. Efforts to exploit A. paniculata extracts enriched in andrographolide as preventive measures against such disorders can be warranted.

  9. Aqueous calyxes extract of Roselle or Hibiscus sabdariffa Linn supplementation improves liver morphology in streptozotocin induced diabetic rats.

    Science.gov (United States)

    Nazratun Nafizah, Akhtar Husin; Budin, Siti Balkis; Zaryantey, Abd Hamid; Mariati, Abd Rahman; Santhana, Raj Louis; Osman, Mohamad; Muhd Hanis, Md Idris; Jamaludin, Mohamed

    2017-03-01

    The complex series of deleterious events among diabetes patients leads to multiple organ failure. Therefore, a holistic approach of treatment is urgently required to prevent worsening of complications. The present investigation was carried out to study the possible protective effects of Roselle or Hibiscus sabdariffa Linn (HSL) calyxes aqueous extract, as an antidiabetic and antioxidant agent against oxidative liver injury in streptozotocin-induced diabetic rats. A single dose of streptozotocin (45mg/kg body weight, iv) was used to induced diabetes in male Sprague Dawley rats which were then divided into two groups: Diabetic control (DC) and HSL-treated diabetic (DR) group. Normal rats were divided into normal control (NC), HSL-treated control (NR). Aqueous calyxes extract of HSL (100mg/kg/day, orally) was given for 28 consecutive days in the treated group. Weight, biochemical and histopathological (light and electron microscopic) parameters were compared in all groups. Supplementation of HSL significantly lowered the level of fasting blood glucose and increased plasma insulin level in DR group compared to DC group (p<0.05). Alanine aminotransaminases and aspartate aminotransferase enzymes level were found to be significantly reduced in DR compared to DC. Microscopic examination demonstrated destruction of the liver architecture, cytoplasmic vacuolation of the hepatocytes and signs of necrosis in diabetic rats. Moreover, dilatation and congestion of blood vessels with leucocytes adherence were detected. Ultrastructural study using electron microscope showed homogeneous substance accumulation in nuclear chromatin, a decrease of organelles and mitochondrial degeneration in the diabetic rats. Administration of HSL in diabetic rats causes significant decrease in hepatocyte destruction and prevented the changes associated with the diabetic condition. Thus, our findings provide a scientific rationale for the use of HSL as promising agent in preventing liver injury in

  10. Effect of irradiation on the expression of caspase-3 in the submandibular gland of streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Lee, Heung Ki; Hwang, Eui Hwan; Lee, Sang Rae

    2005-01-01

    To observe the histopathological changes and caspace-3 expression in the submandibular gland in streptozotocin-induced diabetic rats after irradiation. The male Sprague-Dawley rats weighing approximately 250gm were divided into four groups; control, diabetes, irradiation, and diabetes-irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control and irradiation groups were injected with citrate buffer only. After 5 days, rats in irradiation, and diabetes-irradiation groups were irradiated with a single absorbed dose of 10 Gy to the head and neck region. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the submandibular gland were sectioned and observed using histopathological and immunohistochemical methods. In the irradiation group, the condensed nucleus, karyolysis, and degeneration of the acinar cells and atrophy of the duct cells were observed in the early experimental phase. However, the acinar cells were found to be normal at 28 days after irradiation. In the diabetes group, the condensed nucleus, karyolysis, atrophy, and degeneration of the acinar cells were observed in the early experimental phase. However, the acinar cells were found to be normal at 21 days, after diabetic state induction. In the diabetes-irradiation group, the ductal epithelial cells were predominant in their glandular tissues at 28 days after irradiation. In all of the experimental groups, the most prominent change of the acinar cells and ductal cells were observed at 14 days after diabetic state induction and irradiation. The expression of caspase-3 in the acinar cells and ductal cells of the submandibular gland was weak after irradiation, but that in the acinar cells, ductal cells, and fibrous cells of the submandibular gland was prominent after diabetic state induction.

  11. Protective role of 20-OH ecdysone on lipid profile and tissue fatty acid changes in streptozotocin induced diabetic rats.

    Science.gov (United States)

    Naresh Kumar, Rajendran; Sundaram, Ramalingam; Shanthi, Palanivelu; Sachdanandam, Panchanatham

    2013-01-05

    Hyperlipidemia is an associated complication of diabetes mellitus. The association of hyperglycemia with an alteration of lipid parameters presents a major risk for cardiovascular complications in diabetes. The present study was designed to examine the antihyperlipidemic effect of 20-OH ecdysone on lipid profile and tissue fatty acid changes in streptozotocin induced diabetic rats. The levels of blood glucose, cholesterol, triglycerides, free fatty acids, phospholipids, low density lipoprotein, very low density lipoprotein, high density lipoprotein, lipoprotein lipase, lecithin cholesterol acyl transferase, 3-hydroxy 3-methylglutaryl coenzyme A reductase and fatty acid composition were estimated in plasma, liver and kidneys of control and experimental groups of rats. Oral administration of 20-OH ecdysone at a dose of 5mg/kg bodyweight per day to STZ-induced diabetic rats for a period of 30 days resulted in a significant reduction in fasting blood glucose, cholesterol, triglycerides, free fatty acids, phospholipids, low density lipoprotein, very low density lipoprotein, 3-hydroxy 3-methylglutaryl coenzyme A reductase and elevation of high density lipoprotein, lipoprotein lipase and lecithin cholesterol acyl transferasein comparison with diabetic untreated rats. Moreover, administration of 20-OH ecdysone to diabetic rats also decreased the concentrations of fatty acids, viz., palmitic, stearic (16:1) and oleic acid (18:1), whereas linolenic (18:3) and arachidonic acid (20:4) were elevated. The antihyperlipidemic effect of 20-OH ecdysone was compared with glibenclamide a well-known antihyperglycemic drug. The result of the present study indicates that 20-OH ecdysone showed an antihyperlipidemic effect in addition to its antidiabetic effect in experimental diabetes. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Effect of Unripe Plantain (Musa paradisiaca) and Ginger (Zingiber officinale) on Renal Dysfunction in Streptozotocin-Induced Diabetic Rats.

    Science.gov (United States)

    Iroaganachi, Mercy; Eleazu, Chinedum; Okafor, Polycarp

    2015-03-20

    Although unripe plantain (Musa paradisiaca) and ginger (Zingiber officinale) are used as single plants to manage diabetes mellitus in Nigeria, the possibility of combining them in a typical diabetic diet and the glycemic response elicited as a result of such combination has not been investigated. To determine the effect of unripe plantain and ginger on serum total proteins, albumin, creatinine and urea levels of streptozotocin induced diabetic rats. Twenty four male albino rats were used and were divided into 4 groups of 6 rats each. Group 1 (non-diabetic) received standard rat feeds; Group 2 (diabetic) received standard rat feeds; Group 3 received unripe plantain pellets and Group 4 received unripe plantain+ginger pellets. There were significant increases (P=0.045) of both serum urea and creatinine, but significant decreases (P=0.045) of both serum total protein and albumin levels, in Group 2 rats compared with Group 1. There were significant decreases (P=0.033) of both serum urea and creatinine levels of Group 3 and 4 rats compared with Group 2. In addition, there were significant increases of both serum total protein and albumin levels (P=0.033) in Group 3 rats compared with Group 2, but the comparison of serum total protein and albumin levels between Group 4 and Group 2 did not reach the significant level (P=0.056 and P=0.065 for serum total protein and albumin levels, respectively. Combination of unripe plantain and ginger at the ratio used in the management of renal dysfunction in diabetics was not very effective compared with unripe plantain alone.

  13. Effects of parsley (Petroselinum crispum) extract versus glibornuride on the liver of streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Ozsoy-Sacan, Ozlem; Yanardag, Refiye; Orak, Haci; Ozgey, Yasemin; Yarat, Aysen; Tunali, Tugba

    2006-03-08

    Parsley (Petroselinum crispum) is one of the medicinal herbs used by diabetics in Turkey. The aim of this study is to investigate the effects of parsley (2g/kg) and glibornuride (5mg/kg) on the liver tissue of streptozotocin-induced diabetic rats. Swiss albino rats were divided into six groups: control; control+parsley; control+glibornuride; diabetic; diabetic+parsley; diabetic+glibornuride. Diabetes was induced by intraperitoneal injection of 65 mg/kg streptozotocin (STZ). Parsley extract and glibornuride were given daily to both diabetic and control rats separately, until the end of the experiment, at day 42. The drugs were administered to one diabetic and one control group from days 14 to 42. On day 42, liver tissues were taken from each rat. In STZ-diabetic group, blood glucose levels, serum alkaline phosphatase activity, uric acid, sialic acid, sodium and potassium levels, liver lipid peroxidation (LPO), and non-enzymatic glycosylation (NEG) levels increased, while liver glutathione (GSH) levels and body weight decreased. In the diabetic group given parsley, blood glucose, serum alkaline phosphatase activity, sialic acid, uric acid, potassium and sodium levels, and liver LPO and NEG levels decreased, but GSH levels increased. The diabetic group, given glibornuride, blood glucose, serum alkaline phosphatase activity, serum sialic acid, uric acid, potassium, and liver NEG levels decreased, but liver LPO, GSH, serum sodium levels, and body weight increased. It was concluded that probably, due to its antioxidant property, parsley extract has a protective effect comparable to glibornuride against hepatotoxicity caused by diabetes.

  14. Remote ischemic preconditioning differentially attenuates post-ischemic cardiac arrhythmia in streptozotocin-induced diabetic versus nondiabetic rats.

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    Hu, Zhaoyang; Chen, Mou; Zhang, Ping; Liu, Jin; Abbott, Geoffrey W

    2017-04-26

    Sudden cardiac death (SCD), a leading cause of global mortality, most commonly arises from a substrate of cardiac ischemia, but requires an additional trigger. Diabetes mellitus (DM) predisposes to SCD even after adjusting for other DM-linked cardiovascular pathology such as coronary artery disease. We previously showed that remote liver ischemia preconditioning (RLIPC) is highly protective against cardiac ischemia reperfusion injury (IRI) linked ventricular arrhythmias and myocardial infarction, via induction of the cardioprotective RISK pathway, and specifically, inhibitory phosphorylation of GSK-3β (Ser 9). We evaluated the impact of acute streptozotocin-induced DM on coronary artery ligation IRI-linked ventricular arrhythmogenesis and RLIPC therapy in rats. Post-IRI arrhythmia induction was similar in nondiabetic and DM rats, but, unexpectedly, DM rats exhibited lower incidence of SCD during reperfusion (41 vs. 100%), suggesting uncontrolled hyperglycemia does not acutely predispose to SCD. RLIPC was highly effective in both nondiabetic and DM rats at reducing incidence and duration of, and increasing latency to, all classes of ventricular tachyarrhythmias. In contrast, atrioventricular block (AVB) was highly responsive to RLIPC in nondiabetic rats (incidence reduced from 72 to 18%) but unresponsive in DM rats. RISK pathway induction was similar in nondiabetic and DM rats, thus not explaining the DM-specific resistance of AVB to therapy. Our findings uncover important acute DM-specific differences in responsiveness to remote preconditioning for ventricular tachyarrhythmias versus AVB, which may have clinical significance given that AVB is a malignant arrhythmia twofold more common in human diabetics than nondiabetics, and correlated to plasma glucose levels >10 mmol/L.

  15. Protective effects of methanolic extract of Juglans regia L. leaf on streptozotocin-induced diabetic peripheral neuropathy in rats.

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    Nasiry, Davood; Khalatbary, Ali Reza; Ahmadvand, Hassan; Talebpour Amiri, Fereshteh; Akbari, Esmaeil

    2017-10-02

    Oxidative stress has a pivotal role in the pathogenesis and development of diabetic peripheral neuropathy (DPN), the most common and debilitating complications of diabetes mellitus. There is accumulating evidence that Juglans regia L. (GRL) leaf extract, a rich source of phenolic components, has hypoglycemic and antioxidative properties. This study aimed to determine the protective effects of Juglans regia L. leaf extract against streptozotocin-induced diabetic neuropathy in rat. The DPN rat model was generated by intraperitoneal injection of a single 55 mg/kg dose of streptozotocin (STZ). A subset of the STZ-induced diabetic rats intragastically administered with GRL leaf extract (200 mg/kg/day) before or after the onset of neuropathy, whereas other diabetic rats received only isotonic saline as the same volume of GRL leaf extract. To evaluate the effects of GRL leaf extract on the diabetic neuropathy various parameters, including histopathology and immunohistochemistry of apoptotic and inflammatory factors were assessed along with nociceptive and biochemical assessments. Degeneration of the sciatic nerves which was detected in the STZ-diabetic rats attenuated after GRL leaf extract administration. Greater caspase-3, COX-2, and iNOS expression could be detected in the STZ-diabetic rats, which were significantly attenuated after GRL leaf extract administration. Also, attenuation of lipid peroxidation and nociceptive response along with improved antioxidant status in the sciatic nerve of diabetic rats were detected after GRL leaf extract administration. In other word, GRL leaf extract ameliorated the behavioral and structural indices of diabetic neuropathy even after the onset of neuropathy, in addition to blood sugar reduction. Our results suggest that GRL leaf extract exert preventive and curative effects against STZ-induced diabetic neuropathy in rats which might be due to its antioxidant, anti-inflammatory, and antiapoptotic properties. Protection against

  16. Effect of Livingstone Potato ( N.E.Br on Diabetes and Its Complications in Streptozotocin Induced Diabetes in Rats

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    Chinedum Ogbonnaya Eleazu

    2014-10-01

    Full Text Available BackgroundThe effect of livingstone potato (Plectranthus esculenthus N.E.Br on diabetes and its complications in Streptozotocin induced diabetic rats was investigated. The duration of the experiment was 4 weeks.MethodsThe blood glucose level of the rats was measured with a glucometer, the protein and glucose and specific gravity in the urine samples of the rats were measured using urine assay strips and urinometer respectively. The liver and kidney function parameters in the serum of the rats were determined using Biosystem Kits.ResultsThe diabetic rats given livingstonepotato incorporated feeds, had 129.7% decrease in their hyperglycemia with corresponding amelioration of their elevated urinary protein, sugars, specific gravity, renal growth, liver growth as well as 15.64% decrease in body weights compared with the nondiabetic rats that had 5.54% decrease in blood glucose and 20.39% increase in body weight unlike the diabetic control rats that had 18.34% decrease in blood glucose and 52.68% decrease in body weight. There were significant differences (P0.05 in the relative heart weights of all the rats in the three different groups. In terms of liver and kidney function parameters, values obtained for the diabetic rats given livingstone potato incorporated feeds were not significantly different from that of the nondiabetic rats except for total bilurubin, aspartate transaminase, and creatinine (P>0.05 while they were significantly different from the values obtained for the diabetic control rats (P<0.05. In addition, the serum amylase of the diabetic control rats were significantly higher (P<0.05 than that of the nondiabetic and diabetic rats treated with livingstone potato incorporated feeds.ConclusionResults show the antidiabetic actions of livingstone potato and its ability to ameliorate glomerular complication and liver hypertrophy in diabetics.

  17. Dendrobium officinale Kimura et Migo attenuates diabetic cardiomyopathy through inhibiting oxidative stress, inflammation and fibrosis in streptozotocin-induced mice.

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    Zhang, Zhihao; Zhang, Duoduo; Dou, Mengmeng; Li, Zhubo; Zhang, Jie; Zhao, Xiaoyan

    2016-12-01

    Dendrobium officinale Kimura et Migo (Dendrobium catenatum Lindley), a prized traditional Chinese Medicine, has been used in China and Southeast Asian countries for centuries. The present study was aimed to investigate the effects and the possible mechanisms of the Dendrobium officinale extracts (DOE) on diabetic cardiomyopathy in mice. The diabetic model was induced by intraperitoneal injection of streptozotocin at the dose of 50mg/kg body weight for 5 consecutive days. After 8 weeks treatment of DOE, mice were sacrificed, blood sample and heart tissues were collected. Our results showed that Streptozotocin-induced diabetic model was effectively achieved and serum CK and LDH levels were significantly increased in mice with diabetic cardiomyopathy. Pretreatment with DOE decreased the heart-to-body weight ratio (HW/BW) and showed an evident hypoglycemic effect. DOE pretreatment significantly decreased CK, LDH, TC and TG levels, limited the production of MDA and increased the activities of T-SOD. The histological analysis of Oil red O staining and Sirius red staining showed an obvious amelioration of cardiac injury, inhibition of cardiac lipid accumulation and deposition of collagen when pretreatment with DOE. In addition, Western blot detection and analysis showed that DOE down-regulated the expression of TGF-β, collegan-1, fibronectin, NF-κB, TNF-α and IL-1β. In conclusion, our study suggested that DOE possesses the cardioprotective potential against diabetic cardiomyopathy, which may be due to the inhibition of oxidative stress, cardiac lipid accumulation, pro-inflammatory cytokines and cardiac fibrosis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  18. Antidiabetic Properties and Mechanism of Action of Gynura procumbens Water Extract in Streptozotocin-Induced Diabetic Rats

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    Mariam Ahmad

    2010-12-01

    Full Text Available Gynura procumbens (Lour. Merr (family Compositae is cultivated in Southeast Asia, especially Indonesia, Malaysia and Thailand, for medicinal purposes. This study evaluated the in vivo hypoglycemic properties of the water extract of G. procumbens following 14 days of treatment and in vitro in RIN-5F cells. Glucose absorption from the intestines and its glucose uptake in abdominal skeletal muscle were assessed. The antidiabetic effect of water extract of G. procumbens leaves was investigated in streptozotocin-induced diabetic rats. The intraperitoneal glucose tolerance test (IPGTT was performed in diabetic rats treated with G. procumbens water extract for 14 days. In the IPGTT, blood was collected for insulin and blood glucose measurement. After the IPGTT, the pancreases were collected for immunohistochemical study of β-cells of the islets of Langerhans. The possible antidiabetic mechanisms of G. procumbens were assessed through in vitro RIN-5F cell study, intestinal glucose absorption and glucose uptake by muscle. The results showed that G. procumbens significantly decreased blood glucose levels after 14 days of treatment and improved outcome of the IPGTT. However, G. procumbens did not show a significant effect on insulin level either in the in vivo test or the in vitro RIN-5F cell culture study. G. procumbens also showed minimal effects on β-cells of the islets of Langerhans in the pancreas. However, G. procumbens only significantly increased glucose uptake by muscle tissues. From the findings we can conclude that G. procumbens water extract exerted its hypoglycemic effect by promoting glucose uptake by muscles.

  19. Effects of the blended fibroin/aloe gel film on wound healing in streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Inpanya, Paichit; Viyoch, Jarupa; Faikrua, Atchariya; Ounaroon, Anan; Sittichokechaiwut, Anuphan

    2012-01-01

    Delayed healing remains a major clinical problem and here we have sought to develop an improved dressing film comprising 1.95% w/v fibroin and 0.05% w/v aloe gel extract. The tensile strength of dry film was 21.1 ± 0.5 MPa and broke at 1.1 ± 0.2% elongation; corresponding values for wet film were 18.3 ± 1.3 MPa and 1.9 ± 0.1%. The film maintained its shape upon water immersion and the swelling ratio of the dry film was 0.8 ± 0.1 while the water uptake was 43.7 ± 2.6%. After 28 days of incubation in phosphate buffered saline (1 M, pH 7.4, 37 °C), the weight of film was reduced by 6.7 ± 1.1% and the tensile strength and elongation at breaking point (dry state) were 15.4 ± 0.6 MPa and 1.5 ± 0.2%, respectively. Compared to aloe-free fibroin film (2.0% fibroin extract only), the blended film enhanced the attachment and proliferation of skin fibroblasts. The bFGF immunofluorescence of fibroblasts cultured on the blended film appeared greater than those cultured on tissue culture plate or on aloe-free fibroin film while α-smooth muscle actin was maintained. In streptozotocin-induced diabetic rats, the wounds dressed with the blended film were smaller (p <0.05) by day 7 after wounding, compared to untreated diabetic wounds. Histology of repaired diabetic wounds showed the fibroblast distribution and collagen fiber organization to be similar to wounds in normal rats, and this was matched by enhanced hydroxyproline content. Thus, such accelerated wound healing by the blended fibroin/aloe gel films may find application in treatment of diabetic non-healing skin ulcers. (paper)

  20. Effect of acacia nilotica leaves extract on hyperglycaemia, lipid profile and platelet aggregation in streptozotocin induced diabetic rats

    International Nuclear Information System (INIS)

    Asad, M.; Munir, T.A.; Nadeem, A.

    2011-01-01

    To consider new hypoglycaemic, anti-hyperlipidaemic and anti-platelet aggregation sources, aqueous methanol extract of Acacia Nilotica (AN) leaves was investigated in streptozotocin induced diabetic rats. Methods: Diabetes mellitus was induced in 90 out of 120 male albino rats by administering 50 mg/Kg body weight (bw) streptozotocin intraperitoneal y, and was confirmed by measuring fasting blood glucose level >200 mg/dL on fourth post-induction day. The rats were equally divided into 4 groups, A (normal control), B (diabetic control), C (diabetics rats treated with plant extract) and group D (diabetics rats treated with glyburide). The rats of group C and D were given single dose of 300 mg/Kg bw, An extract, and 900 micro g/Kg bw glyburide respectively for 3 weeks. Blood glucose levels were measured by gluco meter, platelet aggregation by Dia Med method, beta-thrombo globulin and insulin by ELISA technique, and lipid components were measured by enzymatic calorimetric method. Results: Significant differences (p<0.05) were noticed in blood glucose, serum insulin, platelet aggregation and triglyceride levels in diabetic rats treated with AN extract and glyburide as compared to diabetic controlled rats. A significant difference (p<0.05) in beta-thrombo globulin and LDL levels was also noticed in rats treated with glyburide than the diabetic controlled rats. The levels of fasting blood glucose, beta-thrombo globulin and platelet aggregation were significantly reduced (p<0.05) in diabetic rats treated with glyburide than AN extract treated rats. Conclusions: Administration of AN leaves extract showed hypoglycaemic and anti-platelet aggregation activity in diabetic rats as that of glyburide. (author)

  1. Relative influence of sulodexide and pentoxifylline to the skin microcirculation in the experimental streptozotocin-induced diabetic angiopathy

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    O. V. Chekhlova

    2015-02-01

    вторы делают вывод о том, что полученные данные являются экспериментальным обоснованием целесообразности клинического применения сулодексида при лечении диабетической ангиопатии, а также его применения с профилактической целью у больных сахарным диабетом.   Ключевые слова: сахарный диабет, диабетическая ангиопатия, сосуды микроциркуляторного русла, сулодексид, пентоксифиллин, патогенетическая терапия.   Abstract   The data of the experimental trials are given devoted to the sulodexide comparative therapeutic efficacy investigation in conditions of experimental streptozotocine-induced diabetic angiopathy. Pentoxifylline widely used in cases of microcirculatory vessels diabetic damages was chosen as the comparative drug.  The data obtained showed the possibility pf diabetic angiopathy development in streptozotocine-treated diabetic rats 6 weeks from the beginning of the trials. Sulodexide and pentoxifylline were effective in diabetic angiopathy treatment that resulted in microcirculatory vessels all links restoration. Sulodexide, unlike pentoxifylline, improves mainly precapillary link of the microcirculatory vessels.  Sulodexide antithrombotic efficacy prevails the same in pentoxifylline. Sulodexide treatment resulted in the more effective endothelial structure and function restoration compare with pentoxifylline. The authors conclude that the data obtained are the experimental background of sulodexide clinical efficacy testing reasonability in diabetic angiopathy treatment as well in case of its prophylactic use in diabetic patients.   Key words: diabetus mellitus, diabetic angiopathy, microcirculatory vessels, sulodexide

  2. Anti-diabetic effects of Sargassum oligocystum on Streptozotocin- induced diabetic rat

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    Samad Akbarzadeh

    2018-03-01

    Full Text Available Objective(s: Diabetes is a metabolic syndrome which is associated with the worldwide major public health problems. There are many natural compounds from the sea-market, as a valuable aquatic source, along with the variety of health and therapeutic benefits. In the present research, with respect to the traditional and ethnic uses of Sargassum oligocystum algae for healing of some diseases which have similar metabolic mechanism to the diabetes, its anti-diabetic effects in animal model was proposed. Materials and Methods: The animals (rat were divided into the normal control, diabetic control, positive control and, the test groups. The test groups were gavaged with oral doses of 150 and 300 mg/kg of algae hydroalcoholic extracts. After 30 days of intervention the serum glucose, cholesterol, triglyceride, HDLC, LDLC, insulin, insulin resistance, β-cells function and, the histopathology of pancreatic tissue were evaluated. Results: In animals that were fed with algae extracts a significant decrease in the fasting blood glucose, triglyceride and HOMA-IR and an increase in the HOMA-B with no significant impacts on the insulin, cholesterol and HDL were observed. Also, the histopathology evaluations in the groups which were treated with algae extract revealed the regeneration and reconstitution of damaged pancreatic β-cells. Conclusion: The results give evidence that, the S. oligocystum algae extract has a healing effect on diabetes which can be considered as a new research prospect for the natural therapy of diabetes.

  3. Neuromodulatory Effects of Hesperidin in Mitigating Oxidative Stress in Streptozotocin Induced Diabetes

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    Mohammad Ashafaq

    2014-01-01

    Full Text Available Oxidative stress has been implicated in pathogenesis of streptozotocin- (STZ- induced diabetes mellitus and its complication in central nervous system (CNS. Recent studies have provided insights on antioxidants and their emergence as potential therapeutic and nutraceutical. The present study examined the hypothesis that hesperidin (HP ameliorates oxidative stress and may be a limiting factor in the extent of CNS complication following diabetes. To test this hypothesis rats were divided into four groups: control, diabetic, diabetic-HP treated, and vehicle for HP treatment group. Diabetes mellitus was induced by a single injection of STZ (65 mg/kg body weight. Three days after STZ injection, HP was given (50 mg/kg b.wt. orally once daily for four weeks. The results of the present investigation suggest that the significant elevated levels of oxidative stress markers were observed in STZ-treated animals, whereas significant depletion in the activity of nonenzymatic antioxidants and enzymatic antioxidants was witnessed in diabetic rat brain. Neurotoxicity biomarker activity was also altered significantly. HP treatment significantly attenuated the altered levels of oxidative stress and neurotoxicity biomarkers. Our results demonstrate that HP exhibits potent antioxidant and neuroprotective effects on the brain tissue against the diabetic oxidative damage in STZ-induced rodent model.

  4. Huperzine A Ameliorates Cognitive Deficits in Streptozotocin-Induced Diabetic Rats

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    Xiao-Yuan Mao

    2014-05-01

    Full Text Available The present study was designed to probe the effects of Huperzine A (HupA on diabetes-associated cognitive decline (DACD using a streptozotocin (STZ-injected rat model. Diabetic rats were treated with HupA (0.05 and 0.1 mg/kg for seven weeks. Memory functions were evaluated by the water maze test. Nissl staining was selected for detecting neuronal loss. Protein and mRNA levels of brain-derived neurotrophic factor (BDNF were analyzed by ELISA and real-time PCR, respectively. The activities of choline acetylase (ChAT, Acetylcholinesterase (AChE, malondialdehyde (MDA, superoxide dismutase (SOD, glutathione peroxidase (GSH-Px, catalase (CAT, NF-κB p65 unit, TNF-α, IL-1β, IL-6 and caspase-3 were measured using corresponding kits. After seven weeks, diabetic rats exhibited remarkable reductions in: body weight, percentage of time spent in target quadrant, number of times crossing the platform, ChAT and BDNF levels, SOD, GSH-Px and CAT accompanied with increases in neuronal damage, plasma glucose levels, escape latency, mean path length, AChE, MDA level as well as CAT, NF-κB p65 unit, TNF-α, IL-1β, IL-6 and caspase-3 in cerebral cortex and hippocampus. Supplementation with HupA significantly and dose-dependently reversed the corresponding values in diabetes. It is concluded that HupA ameliorates DACD via modulating BDNF, oxidative stress, inflammation and apoptosis.

  5. Huperzine A Ameliorates Cognitive Deficits in Streptozotocin-Induced Diabetic Rats

    Science.gov (United States)

    Mao, Xiao-Yuan; Cao, Dan-Feng; Li, Xi; Yin, Ji-Ye; Wang, Zhi-Bin; Zhang, Ying; Mao, Chen-Xue; Zhou, Hong-Hao; Liu, Zhao-Qian

    2014-01-01

    The present study was designed to probe the effects of Huperzine A (HupA) on diabetes-associated cognitive decline (DACD) using a streptozotocin (STZ)-injected rat model. Diabetic rats were treated with HupA (0.05 and 0.1 mg/kg) for seven weeks. Memory functions were evaluated by the water maze test. Nissl staining was selected for detecting neuronal loss. Protein and mRNA levels of brain-derived neurotrophic factor (BDNF) were analyzed by ELISA and real-time PCR, respectively. The activities of choline acetylase (ChAT), Acetylcholinesterase (AChE), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), NF-κB p65 unit, TNF-α, IL-1β, IL-6 and caspase-3 were measured using corresponding kits. After seven weeks, diabetic rats exhibited remarkable reductions in: body weight, percentage of time spent in target quadrant, number of times crossing the platform, ChAT and BDNF levels, SOD, GSH-Px and CAT accompanied with increases in neuronal damage, plasma glucose levels, escape latency, mean path length, AChE, MDA level as well as CAT, NF-κB p65 unit, TNF-α, IL-1β, IL-6 and caspase-3 in cerebral cortex and hippocampus. Supplementation with HupA significantly and dose-dependently reversed the corresponding values in diabetes. It is concluded that HupA ameliorates DACD via modulating BDNF, oxidative stress, inflammation and apoptosis. PMID:24857910

  6. Effect of Potent Ethyl Acetate Fraction of Stereospermum suaveolens Extract in Streptozotocin-Induced Diabetic Rats

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    T. Balasubramanian

    2012-01-01

    Full Text Available To evaluate the antihyperglycemic effect of ethyl acetate fraction of ethanol extract of Stereospermum suaveolens in streptozotocin-(STZ- induced diabetic rats by acute and subacute models. In this paper, various fractions of ethanol extract of Stereospermum suaveolens were prepared and their effects on blood glucose levels in STZ-induced diabetic rats were studied after a single oral administration (200?mg/kg. Administration of the ethyl acetate fraction at 200?mg/kg once daily for 14 days to STZ-induced diabetic rats was also carried out. The parameters such as the fasting blood glucose, hepatic glycogen content, and pancreatic antioxidant levels were monitored. In the acute study, the ethyl acetate fraction is the most potent in reducing the fasting serum glucose levels of the STZ-induced diabetic rats. The 14-day repeated oral administration of the ethyl acetate fraction significantly reduced the fasting blood glucose and pancreatic TBARS level and significantly increased the liver glycogen, pancreatic superoxide dismutase, and catalase activities as well as reduced glutathione levels. The histopathological studies during the subacute treatment have been shown to ameliorate the STZ-induced histological damage of pancreas. This paper concludes that the ethyl acetate fraction from ethanol extract of Stereospermum suaveolens possesses potent antihyperglycemic and antioxidant properties, thereby substantiating the use of plant in the indigenous system of medicine.

  7. Protective effects of y-irradiation to streptozotocin induced diabetic rats: A biochemical and histological study

    International Nuclear Information System (INIS)

    Gharib, O.A.; Noman, E.; Abo-Nour, S.

    2007-01-01

    The present study was conducted to evaluate the possible protective effect of low dose of gamma radiation against pancreatic cells damage in streptozotocin (STZ) diabetic rats. Young male Wister rats were divided into the control group, the irradiated groups, which divided into two subgroups, single irradiated group, which subjected to 0.5 Gy of whole body gamma-irradiation as a single dose and repeated irradiated group, which subjected to 0.5 Gy of whole body gamma-irradiation as a repeated dose (0.5 Gy daily for two days). The 3 r d groups, which in turn subdivided into three subgroups, STZ group administrated to a single dose of 45 mg kg -1 of STZ (i.p), the STZ single irradiated group, subjected to single irradiated dose after the STZ administration and STZ repeated irradiated group, that exposed to repeated dose of radiation after the STZ administration. The diabetic rats presented a significant increase in plasma glucose and lipid peroxidation and a significant decrease in both whole blood SOD and GSH as well as in liver tissue. In addition, marked depression was observed in plasma and liver glutathione- S-transferase compared with normal rats. Low dose of radiation as a single or repeated doses, significantly reduced blood glucose and TEARS and significantly increased SOD activity and GSH content in both blood and liver besides a marked amelioration in GST activity in plasma and liver tissues. The ultra structural studies revealed that STZ affects both cells of pancreas. There was a reduction in secretary granules and rough endoplasmic reticulum with the accumulation of lipid. Low dose of y-rays exposure result a remarkable protective effect on biochemical and histological level

  8. Opposite Expression of SPARC between the Liver and Pancreas in Streptozotocin-Induced Diabetic Rats.

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    Kanikkai Raja Aseer

    Full Text Available Secreted protein acidic and rich in cysteine (SPARC is a matricellular protein that regulates several cellular events, including inflammation and tissue remodelling. In this study, we investigated the tissue-specific expression of SPARC in streptozotocin (STZ-induced diabetes, and found that SPARC was significantly up-regulated in the liver while down-regulated in the pancreas of STZ-induced diabetic rats. Chronic inflammation occurred in the diabetic pancreas accompanied by up-regulation of CCAAT/enhancer-binding protein beta (C/EBPβ and its targets (TNFα, Il6, CRP, and Fn1 as well as myeloperoxidase (Mpo and C-X-C chemokine receptor type 2 (Cxcr2. Diabetic liver showed significant up-regulation of Tgfb1 as well as moderately less up-regulated TNFα and reduced Fn1, resulting in elevated fibrogenesis. PARP-1 was not up-regulated during CD95-mediated apoptosis, resulting in restoration of high ATP levels in the diabetic liver. On the contrary, CD95-dependent apoptosis was not observed in the diabetic pancreas due to up-regulation of PARP-1 and ATP depletion, resulting in necrosis. The cytoprotective machinery was damaged by pancreatic inflammation, whereas adequate antioxidant capacity indicates low oxidative stress in the diabetic liver. High and low cellular insulin content was found in the diabetic liver and pancreas, respectively. Furthermore, we identified six novel interacting partner proteins of SPARC by co-immunoprecipitation in the diabetic liver and pancreas, and their interactions with SPARC were predicted by bioinformatics tools. Taken together, opposite expression of SPARC in the diabetic liver and pancreas may be related to inflammation and immune cell infiltration, degrees of apoptosis and fibrosis, cytoprotective machinery, and cellular insulin levels.

  9. Bioflavonoids Effects of Ginger on Glomerular Podocyte Apoptosis in Streptozotocin-Induced Diabetic Rat

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    Hajhosieni Laleh

    2014-04-01

    Full Text Available Objective: Ginger is a strong antioxidant and long-term treatment of streptozotocin (STZ-diabetic animals, and it has been shown to reduce oxidative stress. Prevalence oxidative stress among urban life and changes in antioxidant capacity are considered asplay an important role in the pathogenesis of chronic diabetes mellitus. Materials and Methods: Wistar male rat (n = 40 were divided into three groups, control group (n = 10 and Ginger Quercetin group that received 100 mg/kg (gavage, (n = 10, and diabetic group, which received 55 mg/kg intra peritoneal (IP STZ (n = 20, which was subdivided to two groups of 10; STZ group and treatment group. Treatment group received 55 mg/kg (IP STZ plus100 mg/kg ginger, daily for, 8 weeks, respectively; however, the control group just received an equal volume of distilled water daily (IP. Diabetes was induced by a single (IP injection of STZ (55 mg/kg. Animals were kept in standard condition. In 28 day after inducing diabetic 5 cc blood were collected for total antioxidant capacity, malondialdehyde and oxidized low density lipoprotein levels and kidney tissues of rat in whole groups were removed then prepared for apoptosis analysis by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay (TUNEL method. Results: Apoptotic cells significantly decreased in group that has received 100 mg/kg ginger (P < 0.05 in comparison to experimental groups (P < 0.05. Conclusion: Since in our study 100 mg/kg ginger have significantly preventive effect on kidney cells damages by reducing number of apoptotic cells in kidney and hence it seems that using it can be effective for treatment in diabetic rat.

  10. Opposite Expression of SPARC between the Liver and Pancreas in Streptozotocin-Induced Diabetic Rats

    Science.gov (United States)

    Aseer, Kanikkai Raja; Kim, Sang Woo; Choi, Myung-Sook; Yun, Jong Won

    2015-01-01

    Secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein that regulates several cellular events, including inflammation and tissue remodelling. In this study, we investigated the tissue-specific expression of SPARC in streptozotocin (STZ)-induced diabetes, and found that SPARC was significantly up-regulated in the liver while down-regulated in the pancreas of STZ-induced diabetic rats. Chronic inflammation occurred in the diabetic pancreas accompanied by up-regulation of CCAAT/enhancer-binding protein beta (C/EBPβ) and its targets (TNFα, Il6, CRP, and Fn1) as well as myeloperoxidase (Mpo) and C-X-C chemokine receptor type 2 (Cxcr2). Diabetic liver showed significant up-regulation of Tgfb1 as well as moderately less up-regulated TNFα and reduced Fn1, resulting in elevated fibrogenesis. PARP-1 was not up-regulated during CD95-mediated apoptosis, resulting in restoration of high ATP levels in the diabetic liver. On the contrary, CD95-dependent apoptosis was not observed in the diabetic pancreas due to up-regulation of PARP-1 and ATP depletion, resulting in necrosis. The cytoprotective machinery was damaged by pancreatic inflammation, whereas adequate antioxidant capacity indicates low oxidative stress in the diabetic liver. High and low cellular insulin content was found in the diabetic liver and pancreas, respectively. Furthermore, we identified six novel interacting partner proteins of SPARC by co-immunoprecipitation in the diabetic liver and pancreas, and their interactions with SPARC were predicted by bioinformatics tools. Taken together, opposite expression of SPARC in the diabetic liver and pancreas may be related to inflammation and immune cell infiltration, degrees of apoptosis and fibrosis, cytoprotective machinery, and cellular insulin levels. PMID:26110898

  11. Neuroprotective effect of ebselen against intracerebroventricular streptozotocin-induced neuronal apoptosis and oxidative stress in rats.

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    Unsal, Cuneyt; Oran, Mustafa; Albayrak, Yakup; Aktas, Cevat; Erboga, Mustafa; Topcu, Birol; Uygur, Ramazan; Tulubas, Feti; Yanartas, Omer; Ates, Ozkan; Ozen, Oguz Aslan

    2016-04-01

    The goal of this study was to examine the neuroprotective effect of ebselen against intracerebroventricular streptozotocin (ICV-STZ)-induced oxidative stress and neuronal apoptosis in rat brain. A total of 30 adult male Sprague-Dawley rats were randomly divided into 3 groups of 10 animals each: control, ICV-STZ, and ICV-STZ treated with ebselen. The ICV-STZ group rats were injected bilaterally with ICV-STZ (3 mg/kg) on days 1 and 3, and ebselen (10 mg/kg/day) was administered for 14 days starting from 1st day of ICV-STZ injection to day 14. Rats were killed at the end of the study and brain tissues were removed for biochemical and histopathological investigation. Our results demonstrated, for the first time, the neuroprotective effect of ebselen on Alzheimer's disease (AD) model in rats. Our present study, in ICV-STZ group, showed significant increase in tissue malondialdehyde levels and significant decrease in enzymatic antioxidants superoxide dismutase and glutathione peroxidase in the frontal cortex tissue. The histopathological studies in the brain of rats also supported that ebselen markedly reduced the ICV-STZ-induced histopathological changes and well preserved the normal histological architecture of the frontal cortex tissue. The number of apoptotic neurons was increased in frontal cortex tissue after ICV-STZ administration. Treatment of ebselen markedly reduced the number of degenerating apoptotic neurons. The study demonstrates the effectiveness of ebselen, as a powerful antioxidant, in preventing the oxidative damage and morphological changes caused by ICV-STZ in rats. Thus, ebselen may have a therapeutic value for the treatment of AD. © The Author(s) 2013.

  12. [Nicorandil improves cognitive dysfunction in mice with streptozotocin-induced diabetes].

    Science.gov (United States)

    Yan, Wen-Hui; Zhang, Chun-Xi; Xing, Tong; Gong, Xue; Yang, Yu-Xuan; Li, Yi-Nuo; Liu, Xuan; Ayijiang, Jiamaliding; Yu, Ye; Zhang, Meng; Chen, Li-Na

    2018-04-20

    To observe the protective effects of potassium channel opener nicorandil against cognitive dysfunction in mice with streptozotocin (STZ)-induced diabetes. C57BL/6J mouse models of type 1 diabetes mellitus (T1DM) were established by intraperitoneal injection of STZ and received daily treatment with intragastric administration of nicorandil or saline (model group) for 4 consecutive weeks, with normal C57BL/6J mice serving as control. Fasting blood glucose level was recorded every week and Morris water maze was used to evaluate the cognitive behavior of the mice in the 4th week. At the end of the experiment, the mice were sacrificed to observe the ultrastructural changes in the hippocampus and pancreas under transmission electron microscopy; the contents of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) in the hippocampus and SOD activity and MDA level in the brain tissue were determined. Compared with the control group, the model group showed significantly increased fasting blood glucose (P<0.001), significantly prolonged escape latency (P<0.05) and increased swimming distance (P<0.01) with ultrastructural damage of pancreatic β cells and in the hippocampus; GIP and GLP-1 contents in the hippocampus (P<0.01) and SOD activity in the brain were significantly decreased (P<0.05) and MDA content was significantly increased in the model group (P<0.05). Compared with the model group, nicorandil treatment did not cause significant changes in fasting blood glucose, but significantly reduced the swimming distance (P<0.05); nicorandil did not improve the ultrastructural changes in pancreatic β cells but obviously improved the ultrastructures of hippocampal neurons and synapses. Nicorandil also significantly increased the contents of GIP and GLP-1 in the hippocampus (P<0.05), enhanced SOD activity (P<0.05) and decreased MDA level (P<0.01) in the brain tissue. Nicorandil improves cognitive dysfunction in mice with STZ-induced diabetes by

  13. Diabetes induced testicular dysfunction amelioration by ethyl acetate fraction of hydromethanolic extract of root of Musa paradisiaca L. in streptozotocin-induced diabetic rat

    Directory of Open Access Journals (Sweden)

    Kausik Chatterjee

    2012-05-01

    Full Text Available Objective: To investigate the diabetic therapeutic potentiality and antioxidative efficacy of ethyl acetate fraction of hydro-methanol (40:60 extract of root of Musa paradisiaca Lam. (Musaceae in streptozotocin-induced diabetic rat. Methods: Streptozotocin-induced diabetic state was confirmed by decreased serum insulin level and carbohydrate metabolomics i.e. increased fasting blood glucose level, glycated hemoglobin level and diminished glycogen contents in liver and skeletal muscle. Reproductive homeostasis alteration in diabetes was evaluated by reproductive organo-somatic indices, sperm count, motility and histological analysis of testicular seminiferous tubule along with levels of serum testosterone, testicular cholesterol and seminal vesicular fructose assessment. Oxidative stress in primary and accessory sex organs, and in sperm pellet was assessed by measuring antioxidant enzyme activities along with quantification of free radicals products. Testicular pro-apoptotic Bax-毩 mRNA expression pattern was studied semi-quantitatively by PCR technique. Reverse phase HPLC fingerprinting was performed using methanol and acetonitrile as mobile phase. Results: Oral administration of ethyl acetate fraction at a dose of 20 mg/0.5 mL of distilled water/100 gm body weight twice daily to the diabetic rats for 28 days significantly recovered organo-somatic indices, protected reproductive activities, corrected oxidative stress markers and pro-apoptotic mRNA expression pattern, which were deviated in diabetes mellitus from control level without any type of toxicity. HPLC fingerprinting shows five completely resolved peaks at 毸 max 254 nm and 342 nm. Conclusions: It has a promising antihyperglycaemic and antioxidative activity for curing diabetes induced reproductive disorders in streptozotocin-induced diabetic rat.

  14. Effects of treadmill running on extracellular basal levels of glutamate and GABA at dentate gyrus of streptozotocin-induced diabetic rats

    Science.gov (United States)

    Reisi, Parham; Alaei, Hojjatallah; Babri, Shirin; Sharifi, Mohammad Reza; Mohaddes, Gisue; Soleimannejad, Elaheh; Rashidi, Bahman

    2010-01-01

    BACKGROUND: The present study evaluated the effects of treadmill running on extracellular basal levels of glutamate and GABA at dentate gyrus of streptozotocin-induced diabetic rats. METHODS: After 12 weeks of diabetes induction and exercise period, extracellular levels of glutamate and GABA were investigated. RESULTS: The results showed that glutamate levels were significantly decreased in diabetes-rest group comparing to the control-rest and the diabetes-exercise groups. CONCLUSIONS: The findings support the possibility that treadmill running is helpful in alleviating neurotransmitter homeostasis and alterations in transmission in diabetes mellitus. PMID:21526077

  15. The physiology of rodent beta-cells in pancreas slices.

    Science.gov (United States)

    Rupnik, M

    2009-01-01

    Beta-cells in pancreatic islets form complex syncytia. Sufficient cell-to-cell electrical coupling seems to ensure coordinated depolarization pattern and insulin release that can be further modulated by rich innervation. The complex structure and coordinated action develop after birth during fast proliferation of the endocrine tissue. These emergent properties can be lost due to various reasons later in life and can lead to glucose intolerance and diabetes mellitus. Pancreas slice is a novel method of choice to study the physiology of beta-cells still embedded in their normal cellulo-social context. I present major advantages, list drawbacks and provide an overview on recent advances in our understanding of the physiology of beta-cells using the pancreas slice approach.

  16. Mechanisms of pancreatic beta-cell growth and regeneration

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    1989-01-01

    Information about the mechanism of beta-cell growth and regeneration may be obtained by studies of insulinoma cells. In the present study the growth and function of the rat insulinoma cell lines RINm5F and 5AH were evaluated by addition of serum, hormones, and growth factors. It was found...... of insulin mRNA content showed that the insulinoma cells only contained about 2% of that of normal rat beta-cells. These results are discussed in relation to the role of growth factors, oncogenes, and differentiation in the growth and regeneration of beta-cells....... that transferrin is the only obligatory factor whereas growth hormone, epidermal growth factor, fibroblast growth factor, and TRH had modulating effects. A heat-labile heparin binding serum factor which stimulated thymidine incorporation but not cell proliferation was demonstrated in human serum. Measurements...

  17. Foodborne cereulide causes beta-cell dysfunction and apoptosis.

    Directory of Open Access Journals (Sweden)

    Roman Vangoitsenhoven

    Full Text Available To study the effects of cereulide, a food toxin often found at low concentrations in take-away meals, on beta-cell survival and function.Cell death was quantified by Hoechst/Propidium Iodide in mouse (MIN6 and rat (INS-1E beta-cell lines, whole mouse islets and control cell lines (HepG2 and COS-1. Beta-cell function was studied by glucose-stimulated insulin secretion (GSIS. Mechanisms of toxicity were evaluated in MIN6 cells by mRNA profiling, electron microscopy and mitochondrial function tests.24 h exposure to 5 ng/ml cereulide rendered almost all MIN6, INS-1E and pancreatic islets apoptotic, whereas cell death did not increase in the control cell lines. In MIN6 cells and murine islets, GSIS capacity was lost following 24 h exposure to 0.5 ng/ml cereulide (P<0.05. Cereulide exposure induced markers of mitochondrial stress including Puma (p53 up-regulated modulator of apoptosis, P<0.05 and general pro-apoptotic signals as Chop (CCAAT/-enhancer-binding protein homologous protein. Mitochondria appeared swollen upon transmission electron microscopy, basal respiration rate was reduced by 52% (P<0.05 and reactive oxygen species increased by more than twofold (P<0.05 following 24 h exposure to 0.25 and 0.50 ng/ml cereulide, respectively.Cereulide causes apoptotic beta-cell death at low concentrations and impairs beta-cell function at even lower concentrations, with mitochondrial dysfunction underlying these defects. Thus, exposure to cereulide even at concentrations too low to cause systemic effects appears deleterious to the beta-cell.

  18. The Beneficial Effect of Fesoterodine, a Competitive Muscarinic Receptor Antagonist on Erectile Dysfunction in Streptozotocin-induced Diabetic Rats.

    Science.gov (United States)

    Yilmaz-Oral, Didem; Bayatli, Nur; Gur, Serap

    2017-09-01

    To investigate the possible role of fesoterodine (a competitive muscarinic receptor antagonist) on erectile dysfunction in streptozotocin-induced diabetic rats. A total of 16 adult male Sprague-Dawley rats were equally divided into control and diabetic groups. Diabetes was induced by a single intravenous injection of streptozotocin (25-35 mg/kg). In vivo erectile responses were evaluated by the stimulation of cavernosal nerves, and measurements were repeated after the intracavernosal injection of fesoterodine (1 µM) in rats. The relaxation responses to fesoterodine were examined via incubation with various inhibitors. The relaxant responses of corpus cavernosum (CC) strips were observed in the presence or the absence of fesoterodine (10 µM). Intracavernous administration of fesoterodine restored in vivo erectile response at 5.0- and 7.5-V levels, except for 2.5 V in diabetic rats. Basal intracavernosal pressure (5.4 ± 0.9 mm Hg) in diabetic rats was markedly increased after injection of fesoterodine (33.9 ± 7.9 mm Hg, P <.001). In bath studies, fesoterodine resulted in a relaxation of CC in a concentration-dependent manner, which was reduced in diabetic rats. Nifedipine (l-type Ca 2+ channel blocker) inhibited maximum fesoterodine-induced relaxation by 58%. The nonselective K + channel blocker tetraethylammonium and glibenclamide incubation did not change the relaxant response to fesoterodine. The relaxant responses to acetylcholine (10 µM), electrical field stimulation (10 Hz), and sodium nitroprusside (0.01 µM) in diabetic rats were increased after incubation with fesoterodine (10 µM). Fesoterodine improved erectile function and relaxation of isolated strips of rat CC. The underlying mechanism of fesoterodine is likely due to the blocking of l-type calcium channels independent of the nitric oxide-cyclic guanosine monophosphate pathway. Further investigations are warranted to fully elucidate the restorative effects of

  19. Mediation of Endogenous β-Endorphin by Tetrandrine to Lower Plasma Glucose in Streptozotocin-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Jen-Hao Hsu

    2004-01-01

    Full Text Available The role of β-endorphin in the plasma glucose-lowering action of tetrandrine in streptozotocin-induced diabetic rats (STZ-diabetic rats was investigated. The plasma glucose concentration was assessed by the glucose oxidase method. The enzyme-linked immunosorbent assay was used to determine the plasma level of β-endorphin-like immunoreactivity (BER. The mRNA levels of glucose transporter subtype 4 (GLUT4 in soleus muscle and phosphoenolpyruvate carboxykinase (PEPCK in the liver of STZ-diabetic rats were detected by Northern blotting analysis. The expressed protein of GLUT4 or PEPCK was characterized by Western blotting analysis. Tetrandrine dose-dependently increased plasma BER in a manner parallel to the decrease of plasma glucose in STZ-diabetic rats. Moreover, the plasma glucose-lowering effect of tetrandrine was inhibited by naloxone and naloxonazine at doses sufficient to block opioid μ-receptors. Further, tetrandrine failed to produce plasma glucose-lowering action in opioid μ-receptor knockout diabetic mice. Bilateral adrenalectomy eliminated the plasma glucose-lowering effect and plasma BER-elevating effect of tetrandrine in STZ-diabetic rats. Both effects were abolished by treatment with hexamethonium or pentolinium at doses sufficient to block nicotinic receptors. Tetrandrine enhanced BER release directly from the isolated adrenal medulla of STZ-diabetic rats and this action was abolished by the blockade of nicotinic receptors. Repeated intravenous administration of tetrandrine (1.0 mg/kg to STZ-diabetic rats for 3 days resulted in an increase in the mRNA and protein levels of the GLUT4 in soleus muscle, in addition to the lowering of plasma glucose. Similar treatment with tetrandrine reversed the elevated mRNA and protein levels of PEPCK in the liver of STZ-diabetic rats. The obtained results suggest that tetrandrine may induce the activation of nicotinic receptors in adrenal medulla to enhance the secretion of

  20. Onion peel extracts ameliorate hyperglycemia and insulin resistance in high fat diet/streptozotocin-induced diabetic rats

    Directory of Open Access Journals (Sweden)

    Kim Ji Yeon

    2011-03-01

    Full Text Available Abstract Background Quercetin derivatives in onions have been regarded as the most important flavonoids to improve diabetic status in cells and animal models. The present study was aimed to examine the hypoglycemic and insulin-sensitizing capacity of onion peel extract (OPE containing high quercetin in high fat diet/streptozotocin-induced diabetic rats and to elucidate the mechanism of its insulin-sensitizing effect. Methods Male Sprague-Dawley rats were fed the AIN-93G diet modified to contain 41.2% fat and intraperitoneally injected with a single dose of streptozotocin (40 mg/kg body weight. One week after injection, the rats with fasting blood glucose levels above 126 mg/dL were randomly divided into 4 groups to treat with high fat diet containing 0 (diabetic control, 0.5, or 1% of OPE or 0.1% quercetin (quercetin equivalent to 1% of OPE for 8 weeks. To investigate the mechanism for the effects of OPE, we examined biochemical parameters (insulin sensitivity and oxidative stresses and protein and gene expressions (pro-inflammatory cytokines and receptors. Results Compared to the diabetic control, hypoglycemic and insulin-sensitizing capability of 1% OPE were demonstrated by significant improvement of glucose tolerance as expressed in incremental area under the curve (P = 0.0148. The insulin-sensitizing effect of OPE was further supported by increased glycogen levels in liver and skeletal muscle (P P = 0.0089, respectively. Quantitative RT-PCR analysis showed increased expression of insulin receptor (P = 0.0408 and GLUT4 (P = 0.0346 in muscle tissues. The oxidative stress, as assessed by superoxide dismutase activity and malondialdehyde formation, plasma free fatty acids, and hepatic protein expressions of IL-6 were significantly reduced by 1% OPE administration (P = 0.0393, 0.0237, 0.0148 and 0.0025, respectively. Conclusion OPE might improve glucose response and insulin resistance associated with type 2 diabetes by alleviating metabolic

  1. Dynamics and Synchrony of Pancreatic beta-cells and Islets

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram

    2006-01-01

    description of these processes and their interactions would provide important input in the search for a better treatment of the disease. The thesis describes several aspects of mathematical modeling of beta-cells relevant for the understanding of glucose stimulated insulin secretion. It consists...... and the synchronized behavior of many coupled beta-cells as well as to the synchrony of islets. Rather than developing new biophysical models, the thesis investigates existing models, their integration and simplifications, and analyzed the corresponding dynamics, in order to use these models for investigating...

  2. Protective Effect of Free and Bound Polyphenol Extracts from Ginger (Zingiber officinale Roscoe on the Hepatic Antioxidant and Some Carbohydrate Metabolizing Enzymes of Streptozotocin-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Mutiu Idowu Kazeem

    2013-01-01

    Full Text Available This study investigated the hepatoprotective effects of polyphenols from Zingiber officinale on streptozotocin-induced diabetic rats by assessing liver antioxidant enzymes, carbohydrate-metabolizing enzymes and liver function indices. Initial oral glucose tolerance test was conducted using 125 mg/kg, 250 mg/kg, and 500 mg/kg body weight of both free and bound polyphenols from Z. officinale. 28 day daily oral administration of 500 mg/kg body weight of free and bound polyphenols from Z. officinale to streptozotocin-induced (50 mg/kg diabetic rats significantly reduced (P<0.05 the fasting blood glucose compared to control groups. There was significant increase (P<0.05 in the antioxidant enzymes activities in the animals treated with both polyphenols. Similarly, the polyphenols normalised the activities of some carbohydrate metabolic enzymes (hexokinase and phosphofructokinase in the liver of the rats treated with it and significantly reduced (P<0.05 the activities of liver function enzymes. The results from the present study have shown that both free and bound polyphenols from Z. officinale especially the free polyphenol could ameliorate liver disorders caused by diabetes mellitus in rats. This further validates the use of this species as medicinal herb and spice by the larger population of Nigerians.

  3. Autophagy in muscle of glucose-infusion hyperglycemia rats and streptozotocin-induced hyperglycemia rats via selective activation of m-TOR or FoxO3.

    Directory of Open Access Journals (Sweden)

    Pengfei Lv

    Full Text Available Autophagy is a conserved process in eukaryotes required for metabolism and is involved in diverse diseases. To investigate autophagy in skeletal muscle under hyperglycemia status, we established two hyperglycemia-rat models that differ in their circulating insulin levels, by glucose infusion and singe high-dose streptozotocin injection. We then detected expression of autophagy related genes with real-time PCR and western blot. We found that under hyperglycemia status induced by glucose-infusion, autophagy was inhibited in rat skeletal muscle, whereas under streptozotocin-induced hyperglycemia status autophagy was enhanced. Meanwhile, hyperglycemic gastrocnemius muscle was more prone to autophagy than soleus muscle. Furthermore, inhibition of autophagy in skeletal muscle in glucose-infusion hyperglycemia rats was mediated by the m-TOR pathway while m-TOR and FoxO3 both contributed to enhancement of autophagy in gastrocnemius muscle in streptozotocin-induced hyperglycemia rats. These data shows that insulin plays a relatively more important role than hyperglycemia in regulating autophagy in hyperglycemia rat muscle through selectively activating the m-TOR or FoxO3 pathway in a fiber-selective manner.

  4. Insulin-like growth factors and pancreas beta cells.

    NARCIS (Netherlands)

    Haeften, T.W. van; Twickler, M.

    2004-01-01

    Abstract Insulin-like growth factors (IGFs) have been implicated in normal growth, and especially foetal pancreas beta-cell development. As low birth weight has been implicated in the development of obesity and type 2 diabetes, much research has evolved into the importance of IGF and their

  5. Insulin-like growth factors and pancreas beta cells

    NARCIS (Netherlands)

    van Haeften, T. W.; Twickler, TB

    Insulin-like growth factors (IGFs) have been implicated in normal growth, and especially foetal pancreas beta-cell development. As low birth weight has been implicated in the development of obesity and type 2 diabetes, much research has evolved into the importance of IGF and their signalling

  6. Imaging the Beta-cell mass: why and how

    DEFF Research Database (Denmark)

    Saudek, Frantisek; Brogren, Carl-Henrik; Manohar, Srirang

    2008-01-01

    is called dihydrotetrabenazine (DTBZ), antibodies to zinc transporter (ZnT-8) and the monoclonal antibody IC2. While DTBZ and antibodies to ZnT-8 showed binding activities to more than beta-cells, the anti-IC2 monoclonal antibody showed binding properties exclusively to insulin-producing beta...

  7. Insulin-like growth factors and pancreas beta cells

    NARCIS (Netherlands)

    van Haeften, T. W.; Twickler, Th B.

    2004-01-01

    Abstract Insulin-like growth factors (IGFs) have been implicated in normal growth, and especially foetal pancreas beta-cell development. As low birth weight has been implicated in the development of obesity and type 2 diabetes, much research has evolved into the importance of IGF and their

  8. Pancreatic beta-cell overexpression of the glucagon receptor gene results in enhanced beta-cell function and mass

    DEFF Research Database (Denmark)

    Gelling, Richard W; Vuguin, Patricia M; Du, Xiu Quan

    2009-01-01

    in vivo, we generated mice overexpressing the Gcgr specifically on pancreatic beta-cells (RIP-Gcgr). In vivo and in vitro insulin secretion in response to glucagon and glucose was increased 1.7- to 3.9-fold in RIP-Gcgr mice compared with controls. Consistent with the observed increase in insulin release...

  9. Effects of Hydro-alcoholic Extract from Arctium lappa L. (Burdock) Root on Gonadotropins, Testosterone, and Sperm Count and Viability in Male Mice with Nicotinamide/ Streptozotocin-Induced Type 2 Diabetes

    OpenAIRE

    AHANGARPOUR, Akram; OROOJAN, Ali Akbar; HEIDARI, Hamid; GHAEDI, Ehsan; TAHERKHANI, Reza

    2015-01-01

    Background: Reproductive dysfunction is a complication of diabetes. Arctium lappa (burdock) root has hypoglycemic and antioxidative properties, which are traditionally used for treatment of impotence and sterility. Therefore, the aim of this study is to investigate the effects of its hydro alcoholic extract on gonadotropin, testosterone, and sperm parameters in nicotinamide/ streptozotocin-induced diabetic mice.

  10. Microculture system for studying monolayers of functional beta-cells.

    Science.gov (United States)

    Dobersen, M J; Scharff, J E; Notkins, A L

    1980-04-01

    A method is described for growing monolayers of newborn rat beta-cells in microculture trays. After disruption of the pancreas with collagenase, islets were isolated by Ficoll density gradient centrifugation, trypsinized to obtain individual cells, and plated in 96-well tissue culture trays. The cells were incubated for the first 3 days in growth medium containing 0.1 mM 3-isobutyl-1-methylxanthine to promote monolayer formation. The cultures could be maintained in a functional state, as defined by their responsiveness to known modulators of insulin secretion, for at least 2 weeks. As few as 1 X 10(3) islet cells/well gave results that were reproducible within +/- 10%. It is suggested that the microculture system for islet cells might prove to be a rapid and reproducible screening technique for studying drugs, viruses, or other agents that affect beta-cell function.

  11. A Figure-of-Merit for Beta Cell Detector Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Foxe, Michael P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Miller, Brian W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Suarez, Rey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hayes, James C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-02

    In order to decrease the minimum detectable activities (MDAs) of beta-gamma radioxenon detectors, it is important to increase the ability to resolve the individual isotopes. One proposed method for doing this is to increase the energy resolution of the beta cell through the use of silicon detectors. While silicon detectors can improve the energy resolution, it is accompanied with a decrease in detection efficiency compared to plastic scintillator beta cells. Due to the uncertainty on the impact of the competing variables, we have developed a figure-of-merit (FOM) capable of determining the impact of detector parameters on the MDAs. By utilizing the FOM to analyze different detectors, we are able to directly compare current and future detectors and estimate their impact on the radioxenon MDAs.

  12. Pathological prolongation of action potential duration as a cause of the reduced alpha-adrenoceptor-mediated negative inotropy in streptozotocin-induced diabetic mice myocardium.

    Science.gov (United States)

    Kanae, Haruna; Hamaguchi, Shogo; Wakasugi, Yumi; Kusakabe, Taichi; Kato, Keisuke; Namekata, Iyuki; Tanaka, Hikaru

    2017-11-01

    Effect of pathological prolongation of action potential duration on the α-adrenoceptor-mediated negative inotropy was studied in streptozotocin-induced diabetic mice myocardium. In streptozotocin-treated mouse ventricular myocardium, which had longer duration of action potential than that in control mice, the negative inotropic response induced by phenylephrine was smaller than that in control mice. 4-Aminopyridine prolonged the action potential duration and decreased the negative inotropy in control mice. Cromakalim shortened the action potential duration and increased the negative inotropy in streptozotocin-treated mice. These results suggest that the reduced α-adrenoceptor-mediated inotropy in the diabetic mouse myocardium is partly due to its prolonged action potential. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  13. Early changes in retinal structure and BMP2 expression in the retina and crystalline lens of streptozotocin-induced diabetic pigs.

    Science.gov (United States)

    Jeong, Jae Seung; Lee, Woon-Kyu; Moon, Yeon Sung; Kim, Na Rae

    2017-09-01

    This study aims to evaluate early changes in retinal structure and BMP2 expression in the retina and crystalline lens by comparing streptozotocin-induced diabetic pigs and normal control group pigs. Five eye samples from five diabetic Micro-pigs (Medikinetics, Pyeongtaek, Korea) and five eye samples from five control pigs bred in a specific pathogen-free area were used. Diabetes was developed through intravenous injection of nicotinamide and streptozotocin, and the average fasting glucose level was maintained at 250 mg/dL or higher for 16 weeks. To evaluate BMP2 expression in the retina and crystalline lens, Western blotting was performed. In Hematoxylin and Eosin staining, most diabetic pigs showed structural abnormalities in the inner plexiform layer. The number of nuclei in the ganglion cell layer within the range of 10 4 µm 2 was 3.78±0.60 for diabetic pigs and 5.57±1.07 for control group pigs, showing a statistically significant difference. In immunohistochemical staining, diabetic retinas showed an overall increase in BMP2 expression. In Western blotting, the average BMP2/actin level of diabetic retinas was 1.19±0.05, showing a significant increase compared to the 1.06±0.03 of the control group retinas ( P =0.016). The BMP2/actin level of diabetic crystalline lenses was similar to the control group crystalline lenses ( P =0.730). Compared to control group pigs, the number of nuclei in the inner nuclear layer of retinas from streptozotocin-induced diabetic pigs decreased, while an increase in BMP2 expression was observed in the retina of diabetic pigs.

  14. Extract of Ginkgo Biloba Ameliorates Streptozotocin-Induced Type 1 Diabetes Mellitus and High-Fat Diet-Induced Type 2 Diabetes Mellitus in Mice.

    Science.gov (United States)

    Rhee, Ki-Jong; Lee, Chang Gun; Kim, Sung Woo; Gim, Dong-Hyeon; Kim, Hyun-Cheol; Jung, Bae Dong

    2015-01-01

    Diabetes mellitus (DM) is caused by either destruction of pancreatic β-cells (type 1 DM) or unresponsiveness to insulin (type 2 DM). Conventional therapies for diabetes mellitus have been developed but still needs improvement. Many diabetic patients have complemented conventional therapy with alternative methods including oral supplementation of natural products. In this study, we assessed whether Ginkgo biloba extract (EGb) 761 could provide beneficial effects in the streptozotocin-induced type 1 DM and high-fat diet-induced type 2 DM murine model system. For the type 1 DM model, streptozotocin-induced mice were orally administered EGb 761 for 10 days prior to streptozotocin injection and then again administered EGb 761 for an additional 10 days. Streptozotocin-treated mice administered EGb 761 exhibited lower blood triglyceride levels, lower blood glucose levels and higher blood insulin levels compared to streptozotocin-treated mice. Furthermore, liver LPL and liver PPAR-α were increased whereas IL-1β and TNF-α were decreased in streptozotocin-injected mice treated with EGb 761 compared to mice injected with streptozotocin alone. For the type 2 DM model, mice were given high-fat diet for 60 days and then orally administered EGb 761 every other day for 80 days. We found that mice given a high-fat diet and EGb 761 showed decreased blood triglyceride levels, increased liver LPL, increased liver PPAR-α and decreased body weight compared to mice given high-fat diet alone. These results suggest that EGb 761 can exert protective effects in both type 1 and type 2 DM murine models.

  15. Beta-Cell Replacement: Pancreas and Islet Cell Transplantation.

    Science.gov (United States)

    Niclauss, Nadja; Meier, Raphael; Bédat, Benoît; Berishvili, Ekaterine; Berney, Thierry

    2016-01-01

    Pancreas and islet transplantation are 2 types of beta-cell replacement therapies for type 1 diabetes mellitus. Since 1966, when pancreas transplantation was first performed, it has evolved to become a highly efficient procedure with high success rates, thanks to advances in surgical technique and immunosuppression. Pancreas transplantation is mostly performed as simultaneous pancreas-kidney transplantation in patients with end-stage nephropathy secondary to diabetes. In spite of its efficiency, pancreas transplantation is still a major surgical procedure burdened by high morbidity, which called for the development of less invasive and hazardous ways of replacing beta-cell function in the past. Islet transplantation was developed in the 1970s as a minimally invasive procedure with initially poor outcomes. However, since the report of the 'Edmonton protocol' in 2000, the functional results of islet transplantation have substantially and constantly improved and are about to match those of whole pancreas transplantation. Islet transplantation is primarily performed alone in nonuremic patients with severe hypoglycemia. Both pancreas transplantation and islet transplantation are able to abolish hypoglycemia and to prevent or slow down the development of secondary complications of diabetes. Pancreas transplantation and islet transplantation should be seen as two complementary, rather than competing, therapeutic approaches for beta-cell replacement that are able to optimize organ donor use and patient care. © 2016 S. Karger AG, Basel.

  16. GABA dramatically improves glucose tolerance in streptozotocin-induced diabetic rats fed with high-fat diet.

    Science.gov (United States)

    Sohrabipour, Shahla; Sharifi, Mohammad Reza; Talebi, Ardeshir; Sharifi, Mohammadreza; Soltani, Nepton

    2018-05-05

    Skeletal muscle, hepatic insulin resistance, and beta cell dysfunction are the characteristic pathophysiological features of type 2 diabetes mellitus. GABA has an important role in pancreatic islet cells. The present study attempted to clarify the possible mechanism of GABA to improve glucose tolerance in a model of type 2 diabetes mellitus in rats. Fifty Wistar rats were divided into five groups: NDC that was fed the normal diet, CD which received a high-fat diet with streptozotocin, CD-GABA animals that received GABA via intraperitoneal injection, plus CD-Ins1 and CD-Ins2 groups which were treated with low and high doses of insulin, respectively. Body weight and blood glucose were measured weekly. Intraperitoneal glucose tolerance test (IPGTT), insulin tolerance test (ITT), urine volume, amount of water drinking, and food intake assessments were performed monthly. The hyperinsulinemic euglycemic clamp was done for assessing insulin resistance. Plasma insulin and glucagon were measured. Abdominal fat was measured. Glucagon receptor, Glucose 6 phosphatase, Phosphoenolpyruvate carboxykinase genes expression were evaluated in liver and Glucose transporter 4 (GLUT4) genes expression and protein translocation were evaluated in the muscle. GABA or insulin therapy improved blood glucose, insulin level, IPGTT, ITT, gluconeogenesis pathway, Glucagon receptor, body weight and body fat in diabetic rats. GLUT4 gene and protein expression increased. GABA whose beneficial effect was comparable to that of insulin, also increased glucose infusion rate during an euglycemic clamp. GABA could improve insulin resistance via rising GLUT4 and also decreasing the gluconeogenesis pathway and Glucagon receptor gene expression. Copyright © 2018. Published by Elsevier B.V.

  17. Scoparia dulcis, a traditional antidiabetic plant, protects against streptozotocin induced oxidative stress and apoptosis in vitro and in vivo.

    Science.gov (United States)

    Latha, Muniappan; Pari, Leelavinothan; Sitasawad, Sandhya; Bhonde, Ramesh

    2004-01-01

    Oxidative stress is implicated in the pathogenesis of diabetic complications. The experiments were performed on normal and experimental male Wistar rats treated with Scoparia dulcis plant extract (SPEt). The effect of SPEt was tested on streptozotocin (STZ) treated Rat insulinoma cell lines (RINm5F cells) and isolated islets in vitro. Administration of an aqueous extract of Scoparia dulcis by intragastric intubation (po) at a dose of 200 mg/kg body weight significantly decreased the blood glucose and lipid peroxidative marker thiobarbituric acid reactive substances (TBARS) with significant increase in the activities of plasma insulin, pancreatic superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) in streptozotocin diabetic rats at the end of 15 days treatment. Streptozotocin at a dose of 10 mug/mL evoked 6-fold stimulation of insulin secretion from isolated islets indicating its insulin secretagogue activity. The extract markedly reduced the STZ-induced lipidperoxidation in RINm5F cells. Further, SPEt protected STZ-mediated cytotoxicity and nitric oxide (NO) production in RINm5F cells. Treatment of RINm5F cells with 5 mM STZ and 10 mug of SPEt completely abrogated apoptosis induced by STZ, suggesting the involvement of oxidative stress. Flow cytometric assessment on the level of intracellular peroxides using fluorescent probe 2'7'-dichlorofluorescein diacetate (DCF-DA) confirmed that STZ (46%) induced an intracellular oxidative stress in RINm5F cells, which was suppressed by SPEt (21%). In addition, SPEt also reduced (33%) the STZ-induced apoptosis (72%) in RINm5F cells indicating the mode of protection of SPEt on RIN m5Fcells, islets, and pancreatic beta-cell mass (histopathological observations). Present study thus confirms antihyperglycemic effect of SPEt and also demonstrated the consistently strong antioxidant properties of Scoparia dulcis used in the traditional medicine. (c) 2004 Wiley Periodicals, Inc.

  18. Histone deacetylases 1 and 3 but not 2 mediate cytokine-induced beta cell apoptosis in INS-1 cells and dispersed primary islets from rats and are differentially regulated in the islets of type 1 diabetic children

    DEFF Research Database (Denmark)

    Lundh, M; Christensen, D P; Damgaard Nielsen, M

    2012-01-01

    onset, HDAC1 was upregulated in beta cells whereas HDAC2 and -3 were downregulated in comparison with five paediatric controls. CONCLUSIONS/INTERPRETATION: These data demonstrate non-redundant functions of islet class I HDACs and suggest that targeting HDAC1 and HDAC3 would provide optimal protection......AIMS/HYPOTHESIS: Histone deacetylases (HDACs) are promising pharmacological targets in cancer and autoimmune diseases. All 11 classical HDACs (HDAC1-11) are found in the pancreatic beta cell, and HDAC inhibitors (HDACi) protect beta cells from inflammatory insults. We investigated which HDACs...... of HDAC1, -2 and -3 rescued INS-1 cells from inflammatory damage. Small hairpin RNAs against HDAC1 and -3, but not HDAC2, reduced pro-inflammatory cytokine-induced beta cell apoptosis in INS-1 and primary rat islets. The protective properties of specific HDAC knock-down correlated with attenuated cytokine...

  19. Beneficial Effect of Jojoba Seed Extracts on Hyperglycemia-Induced Oxidative Stress in RINm5f Beta Cells

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    Sahla Belhadj

    2018-03-01

    Full Text Available Hyperglycemia occurs during diabetes and insulin resistance. It causes oxidative stress by increasing reactive oxygen species (ROS levels, leading to cellular damage. Polyphenols play a central role in defense against oxidative stress. In our study, we investigated the antioxidant properties of simmondsin, a pure molecule present in jojoba seeds, and of the aqueous extract of jojoba seeds on fructose-induced oxidative stress in RINm5f beta cells. The exposure of RINm5f beta cells to fructose triggered the loss of cell viability (−48%, p < 0.001 and disruption of insulin secretion (p < 0.001 associated with of reactive oxygen species (ROS production and a modulation of pro-oxidant and antioxidant signaling pathway. Cell pre-treatments with extracts considerably increased cell viability (+86% p < 0.001 for simmondsin and +74% (p < 0.001 for aqueous extract and insulin secretion. The extracts also markedly decreased ROS (−69% (p < 0.001 for simmondsin and −59% (p < 0.001 for aqueous extract and caspase-3 activation and improved antioxidant defense, inhibiting p22phox and increasing nuclear factor (erythroid-derived 2-like 2 (Nrf2 levels (+70%, p < 0.001 for aqueous extract. Simmondsin had no impact on Nrf2 levels. The richness and diversity of molecules present in jojoba seed extract makes jojoba a powerful agent to prevent the destruction of RINm5f beta cells induced by hyperglycemia.

  20. Role of MicroRNAs in Islet Beta-Cell Compensation and Failure during Diabetes

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    Valérie Plaisance

    2014-01-01

    Full Text Available Pancreatic beta-cell function and mass are markedly adaptive to compensate for the changes in insulin requirement observed during several situations such as pregnancy, obesity, glucocorticoids excess, or administration. This requires a beta-cell compensation which is achieved through a gain of beta-cell mass and function. Elucidating the physiological mechanisms that promote functional beta-cell mass expansion and that protect cells against death, is a key therapeutic target for diabetes. In this respect, several recent studies have emphasized the instrumental role of microRNAs in the control of beta-cell function. MicroRNAs are negative regulators of gene expression, and are pivotal for the control of beta-cell proliferation, function, and survival. On the one hand, changes in specific microRNA levels have been associated with beta-cell compensation and are triggered by hormones or bioactive peptides that promote beta-cell survival and function. Conversely, modifications in the expression of other specific microRNAs contribute to beta-cell dysfunction and death elicited by diabetogenic factors including, cytokines, chronic hyperlipidemia, hyperglycemia, and oxidized LDL. This review underlines the importance of targeting the microRNA network for future innovative therapies aiming at preventing the beta-cell decline in diabetes.

  1. Lack of TXNIP protects against mitochondria-mediated apoptosis but not against fatty acid-induced ER stress-mediated beta-cell death.

    Science.gov (United States)

    Chen, Junqin; Fontes, Ghislaine; Saxena, Geetu; Poitout, Vincent; Shalev, Anath

    2010-02-01

    We have previously shown that lack of thioredoxin-interacting protein (TXNIP) protects against diabetes and glucotoxicity-induced beta-cell apoptosis. Because the role of TXNIP in lipotoxicity is unknown, the goal of the present study was to determine whether TXNIP expression is regulated by fatty acids and whether TXNIP deficiency also protects beta-cells against lipoapoptosis. RESARCH DESIGN AND METHODS: To determine the effects of fatty acids on beta-cell TXNIP expression, INS-1 cells and isolated islets were incubated with/without palmitate and rats underwent cyclic infusions of glucose and/or Intralipid prior to islet isolation and analysis by quantitative real-time RT-PCR and immunoblotting. Using primary wild-type and TXNIP-deficient islets, we then assessed the effects of palmitate on apoptosis (transferase-mediated dUTP nick-end labeling [TUNEL]), mitochondrial death pathway (cytochrome c release), and endoplasmic reticulum (ER) stress (binding protein [BiP], C/EBP homologous protein [CHOP]). Effects of TXNIP deficiency were also tested in the context of staurosporine (mitochondrial damage) or thapsigargin (ER stress). Glucose elicited a dramatic increase in islet TXNIP expression both in vitro and in vivo, whereas fatty acids had no such effect and, when combined with glucose, even abolished the glucose effect. We also found that TXNIP deficiency does not effectively protect against palmitate or thapsigargin-induced beta-cell apoptosis, but specifically prevents staurosporine- or glucose-induced toxicity. Our results demonstrate that unlike glucose, fatty acids do not induce beta-cell expression of proapoptotic TXNIP. They further reveal that TXNIP deficiency specifically inhibits the mitochondrial death pathway underlying beta-cell glucotoxicity, whereas it has very few protective effects against ER stress-mediated lipoapoptosis.

  2. Workshop on programming beta cell development, impairment and regeneration

    DEFF Research Database (Denmark)

    Heller, Scott; Nielsen, Jens Høiriis

    2012-01-01

    Helsingør, the city of Hamlet in Denmark, provided the site for the workshop "Programming Beta Cell Development, Impairment and Regeneration" on October 23-26th, 2011. The same location has held two EASD Islet study group meetings, while the previous three workshops were held in Helsinki, Finland...... (2003), El Perello, Spain (2006) and Peebles, Scotland (2009). The meeting drew 190 attendees from 12 different countries. There were 37 main oral presentations, and 68 posters covered virtually all aspects of the pancreas and provided a dynamic snapshot of the most interesting areas of current...

  3. Hypoglycemic and Nephroprotective Effects of Aqueous Extract of Stevia rebaudiana (Sweet Fraction in Streptozotocin-Induced Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Mohammad mehdi Zangeneh

    2018-01-01

    Conclusion: According to the obtained results, aqueous extract of S. rebaudiana (sweet fraction can regulate the blood glucose levels and inhibit diabetes-induced renal damages. It seems that S. rebaudiana can be used as an antidiabetic and nephroprotective supplement.

  4. The Fas pathway is involved in pancreatic beta cell secretory function

    DEFF Research Database (Denmark)

    Schumann, Desiree M; Maedler, Kathrin; Franklin, Isobel

    2007-01-01

    Pancreatic beta cell mass and function increase in conditions of enhanced insulin demand such as obesity. Failure to adapt leads to diabetes. The molecular mechanisms controlling this adaptive process are unclear. Fas is a death receptor involved in beta cell apoptosis or proliferation, depending...... on the activity of the caspase-8 inhibitor FLIP. Here we show that the Fas pathway also regulates beta cell secretory function. We observed impaired glucose tolerance in Fas-deficient mice due to a delayed and decreased insulin secretory pattern. Expression of PDX-1, a beta cell-specific transcription factor...... regulating insulin gene expression and mitochondrial metabolism, was decreased in Fas-deficient beta cells. As a consequence, insulin and ATP production were severely reduced and only partly compensated for by increased beta cell mass. Up-regulation of FLIP enhanced NF-kappaB activity via NF...

  5. Implications for the offspring of circulating factors involved in beta cell adaptation in pregnancy

    DEFF Research Database (Denmark)

    Nalla, Amarnadh; Ringholm, Lene; Søstrup, Birgitte

    2014-01-01

    is able to stimulate proliferation of rat beta cells. We have identified several circulating factors that may contribute to beta cell adaptation to pregnancy. Further studies are needed to elucidate their possible role in glucose homeostasis in the mother and her offspring.......OBJECTIVE: Several studies have shown an increase in beta cell mass during pregnancy. Somatolactogenic hormones are known to stimulate the proliferation of existing beta cells in rodents whereas the mechanism in humans is still unclear. We hypothesize that in addition to somatolactogenic hormones...... there are other circulating factors involved in beta cell adaptation to pregnancy. This study aimed at screening for potential pregnancy-associated circulating beta cell growth factors. SAMPLES: Serum samples from nonpregnant and pregnant women. METHODS: The effect of serum from pregnant women...

  6. Semi-automated digital measurement as the method of choice for beta cell mass analysis.

    Directory of Open Access Journals (Sweden)

    Violette Coppens

    Full Text Available Pancreas injury by partial duct ligation (PDL activates beta cell differentiation and proliferation in adult mouse pancreas but remains controversial regarding the anticipated increase in beta cell volume. Several reports unable to show beta cell volume augmentation in PDL pancreas used automated digital image analysis software. We hypothesized that fully automatic beta cell morphometry without manual micrograph artifact remediation introduces bias and therefore might be responsible for reported discrepancies and controversy. However, our present results prove that standard digital image processing with automatic thresholding is sufficiently robust albeit less sensitive and less adequate to demonstrate a significant increase in beta cell volume in PDL versus Sham-operated pancreas. We therefore conclude that other confounding factors such as quality of surgery, selection of samples based on relative abundance of the transcription factor Neurogenin 3 (Ngn3 and tissue processing give rise to inter-laboratory inconsistencies in beta cell volume quantification in PDL pancreas.

  7. Göttingen minipig model of diet-induced atherosclerosis: influence of mild streptozotocin-induced diabetes on lesion severity and markers of inflammation evaluated in obese, obese and diabetic, and lean control animals

    DEFF Research Database (Denmark)

    Ludvigsen, Trine Pagh; Kirk, Rikke Kaae; Christoffersen, Berit Østergaard

    2015-01-01

    in human patients, inclusion of this disease aspect in the characterization of a such model, is highly relevant. The objective of this study was to evaluate the effect of mild streptozotocin-induced diabetes on ex- and in vivo end-points in a diet-induced atherosclerotic minipig model. Castrated male...... Göttingen minipigs were fed standard chow (CD), atherogenic diet alone (HFD) or with superimposed mild streptozotocin-induced diabetes (HFD-D). Circulating markers of inflammation (C-reactive protein (CRP), oxidized low-density lipoprotein (oxLDL), plasminogen activator inhibitor-1, lipid and glucose......From a pharmacological perspective, readily-available, well-characterized animal models of cardiovascular disease, including relevant in vivo markers of atherosclerosis are important for evaluation of novel drug candidates. Furthermore, considering the impact of diabetes mellitus on atherosclerosis...

  8. Optical redox ratio using endogenous fluorescence to assess the metabolic changes associated with treatment response of bioconjugated gold nanoparticles in streptozotocin-induced diabetic rats

    Science.gov (United States)

    Adavallan, K.; Gurushankar, K.; Nazeer, Shaiju S.; Gohulkumar, M.; Jayasree, Ramapurath S.; Krishnakumar, N.

    2017-06-01

    Fluorescence spectroscopic techniques have the potential to assess the metabolic changes during disease development and evaluation of treatment response in a non-invasive and label-free manner. The present study aims to evaluate the effect of mulberry-mediated gold nanoparticles (MAuNPs) in comparison with mulberry leaf extract alone (MLE) for monitoring endogenous fluorophores and to quantify the metabolic changes associated with mitochondrial redox states during streptozotocin-induced diabetic liver tissues using fluorescence spectroscopy. Two mitochondrial metabolic coenzymes, reduced nicotinamide dinucleotide (NADH) and oxidized flavin adenine dinucleotide (FAD) are autofluorescent and are important optical biomarkers to estimate the redox state of a cell. Significant differences in the autofluorescence spectral signatures between the control and the experimental diabetic animals have been noticed under the excitation wavelength at 320 nm with emission ranging from 350-550 nm. A direct correlation between the progression of diabetes and the levels of collagen and optical redox ratio was observed. The results revealed that a significant increase in the emission of collagen in diabetic liver tissues as compared with the control liver tissues. Moreover, there was a significant decrease in the optical redox ratio (FAD/(FAD  +  NADH)) observed in diabetic control liver tissues, which indicates an increased oxidative stress compared to the liver tissues of control rats. Further, the extent of increased oxidative stress was confirmed by the reduced levels of reduced glutathione (GSH) in diabetic liver tissues. On a comparative basis, treatment with MAuNPs was found to be more effective than MLE for reducing the progression of diabetes and improving the optical redox ratio to a near normal range in streptozotocin-induced diabetic liver tissues. Furthermore, principal component analysis followed by linear discriminant analysis (PC-LDA) has been used to

  9. Ins1 Cre knock-in mice for beta cell-specific gene recombination

    OpenAIRE

    Thorens Bernard; Tarussio David; Maestro Miguel Angel; Maestro Miguel Angel; Rovira Meritxell; Rovira Meritxell; Heikkilä Eija; Ferrer Jorge; Ferrer Jorge; Ferrer Jorge

    2013-01-01

    Aims/hypothesis Pancreatic beta cells play a central role in the control of glucose homeostasis by secreting insulin to stimulate glucose uptake by peripheral tissues. Understanding the molecular mechanisms that control beta cell function and plasticity has critical implications for the pathophysiology and therapy of major forms of diabetes. Selective gene inactivation in pancreatic beta cells, using the Cre-lox system, is a powerful approach to assess the role of particular genes in beta cel...

  10. Generation of Transplantable Beta Cells for Patient-Specific Cell Therapy

    Directory of Open Access Journals (Sweden)

    Xiaojie Wang

    2012-01-01

    Full Text Available Islet cell transplantation offers a potential cure for type 1 diabetes, but it is challenged by insufficient donor tissue and side effects of current immunosuppressive drugs. Therefore, alternative sources of insulin-producing cells and isletfriendly immunosuppression are required to increase the efficiency and safety of this procedure. Beta cells can be transdifferentiated from precursors or another heterologous (non-beta-cell source. Recent advances in beta cell regeneration from somatic cells such as fibroblasts could circumvent the usage of immunosuppressive drugs. Therefore, generation of patient-specific beta cells provides the potential of an evolutionary treatment for patients with diabetes.

  11. Structural alterations in rat liver proteins due to streptozotocin-induced diabetes and the recovery effect of selenium: Fourier transform infrared microspectroscopy and neural network study

    Science.gov (United States)

    Bozkurt, Ozlem; Haman Bayari, Sevgi; Severcan, Mete; Krafft, Christoph; Popp, Jürgen; Severcan, Feride

    2012-07-01

    The relation between protein structural alterations and tissue dysfunction is a major concern as protein fibrillation and/or aggregation due to structural alterations has been reported in many disease states. In the current study, Fourier transform infrared microspectroscopic imaging has been used to investigate diabetes-induced changes on protein secondary structure and macromolecular content in streptozotocin-induced diabetic rat liver. Protein secondary structural alterations were predicted using neural network approach utilizing the amide I region. Moreover, the role of selenium in the recovery of diabetes-induced alterations on macromolecular content and protein secondary structure was also studied. The results revealed that diabetes induced a decrease in lipid to protein and glycogen to protein ratios in diabetic livers. Significant alterations in protein secondary structure were observed with a decrease in α-helical and an increase in β-sheet content. Both doses of selenium restored diabetes-induced changes in lipid to protein and glycogen to protein ratios. However, low-dose selenium supplementation was not sufficient to recover the effects of diabetes on protein secondary structure, while a higher dose of selenium fully restored diabetes-induced alterations in protein structure.

  12. Evaluation of antidiabetic, antihyperlipidemic and antioxidant effects of Boehmeria nivea (L. Gaudich., Urticaceae, root extract in streptozotocin-induced diabetic rats

    Directory of Open Access Journals (Sweden)

    Shruti Sancheti

    2011-02-01

    Full Text Available The potential role of 80% methanolic extract of Boehmeria nivea (L. Gaudich., Urticaceae, root in the treatment of diabetes, along with its antihyperlipidemic and antioxidant effects, was studied in streptozotocin-induced diabetic male Wistar rats. Preliminary screening of the extract revealed the presence of polyphenolics and flavonoids. The animal study was conducted with variable doses of 125, 250 and 500 mg/kg of extract for 21 days in diabetic rats. A significant effect was observed at a dose of 500 mg/kg, which was comparable to the standard drug, glibenclamide. Administration of the extract at a 500 mg/kg dose resulted in a significant reduction of fasting blood glucose, total cholesterol, triglycerides, blood urea, alanine aminotransferase, aspartate aminotransferase, urine sugar and urine ketone levels in diabetic rats in comparison with the diabetic control group. Additionally, this dose significantly increased body weight, hemoglobin, plasma total protein, high density lipoprotein cholesterol, liver glycogen content, superoxide dismutase, reduced glutathione and catalase levels in diabetic rats at the end of 21 days of treatment. Therefore, dietary supplementation with Boehmeria nivea root extract could be beneficial for correcting hyperglycemia, hyperlipidemia and enhancing the antioxidant defense system.

  13. Effect of Bauhinia forficata aqueous extract on the maternal-fetal outcome and oxidative stress biomarkers of streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Volpato, G T; Damasceno, D C; Rudge, M V C; Padovani, C R; Calderon, I M P

    2008-02-28

    Bauhinia forficata Link, commonly known as "paw-of-cow", is widely used in Brazilian folk medicine for the treatment of diabetes. To evaluate the effect of Bauhinia forficata treatment on maternal-fetal outcome and antioxidant systems of streptozotocin-induced diabetic rats. Virgin female Wistar rats were injected with 40 mg/kg streptozotocin before mating. Oral administration of an aqueous extract of Bauhinia forficata leaves was given to non-diabetic and diabetic pregnant rats at increasing doses: 500 mg/kg from 0 to 4th day of pregnancy, 600 mg/kg from 5th to 14th day and 1000 mg/kg from 15th to 20th day. At day 21 of pregnancy the rats were anaesthetized with ether and a maternal blood sample was collected for the determination superoxide dismutase (SOD) and reduced glutathione (GSH). The gravid uterus was weighed with its contents and fetuses were analyzed. The data showed that the diabetic dams presented an increased glycemic level, resorption, placental weight, placental index, and fetal anomalies, and reduced GSH and SOD determinations, live fetuses, maternal weight gain, gravid uterine weight, and fetal weight. It was also verified that Bauhinia forficata treatment had no hypoglycemic effect, did not improve maternal outcomes in diabetic rats, but it contributed to maintain GSH concentration similarly to non-diabetic groups, suggesting relation with the decreased incidence of visceral anomalies.

  14. Protective effect of Pterocarpus marsupium bark extracts against cataract through the inhibition of aldose reductase activity in streptozotocin-induced diabetic male albino rats.

    Science.gov (United States)

    Xu, YanLi; Zhao, Yongxia; Sui, YaNan; Lei, XiaoJun

    2018-04-01

    The present study was aimed to investigate the protective effect of Pterocarpus marsupium bark extracts against cataract in streptozotocin-induced diabetic male albino rats. Aldose reductase is a key enzyme in the intracellular polyol pathway, which plays a major role in the development of diabetic cataract. Rats were divided into five groups as normal control, diabetic control, and diabetic control treated with different concentrations of Pterocarpus marsupium bark extracts. Presence of major constituents in Pterocarpus marsupium bark extract was performed by qualitative analysis. Body weight changes, blood glucose, blood insulin, and reduced glutathione (GSH) and aldose reductase mRNA and protein expression were determined. Rat body weight gain was noted following treatment with bark extracts. The blood glucose was reduced up to 36% following treatment with bark extracts. The blood insulin and tissue GSH contents were substantially increased more than 100% in diabetic rats following treatment with extracts. Aldose reductase activity was reduced up to 79.3% in diabetic rats following treatment with extracts. V max , K m , and K i of aldose reductase were reduced in the lens tissue homogenate compared to the diabetic control. Aldose reductase mRNA and protein expression were reduced more than 50% following treatment with extracts. Treatment with Pterocarpus marsupium bark was able to normalize these levels. Taking all these data together, it is concluded that the use of Pterocarpus marsupium bark extracts could be the potential therapeutic approach for the reduction of aldose reductase against diabetic cataract.

  15. Differential Responses to Blood Pressure and Oxidative Stress in Streptozotocin-Induced Diabetic Wistar-Kyoto Rats and Spontaneously Hypertensive Rats: Effects of Antioxidant (Honey) Treatment

    Science.gov (United States)

    Erejuwa, Omotayo O.; Sulaiman, Siti A.; Wahab, Mohd Suhaimi Ab; Sirajudeen, Kuttulebbai N. S.; Salleh, Md Salzihan Md; Gurtu, Sunil

    2011-01-01

    Oxidative stress is implicated in the pathogenesis and/or complications of hypertension and/or diabetes mellitus. A combination of these disorders increases the risk of developing cardiovascular events. This study investigated the effects of streptozotocin (60 mg/kg; ip)-induced diabetes on blood pressure, oxidative stress and effects of honey on these parameters in the kidneys of streptozotocin-induced diabetic Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Diabetic WKY and SHR were randomized into four groups and received distilled water (0.5 mL) and honey (1.0 g/kg) orally once daily for three weeks. Control SHR had reduced malondialdehyde (MDA) and increased systolic blood pressure (SBP), catalase (CAT) activity, and total antioxidant status (TAS). SBP, activities of glutathione peroxidase (GPx) and glutathione reductase (GR) were elevated while TAS was reduced in diabetic WKY. In contrast, SBP, TAS, activities of GPx and GR were reduced in diabetic SHR. Antioxidant (honey) treatment further reduced SBP in diabetic SHR but not in diabetic WKY. It also increased TAS, GSH, reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio, activities of GPx and GR in diabetic SHR. These data suggest that differences in types, severity, and complications of diseases as well as strains may influence responses to blood pressure and oxidative stress. PMID:21673929

  16. Amelioration of hyperglycaemia and its associated complications by finger millet ( Eleusine coracana L.) seed coat matter in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Shobana, Shanmugam; Harsha, Mysore R; Platel, Kalpana; Srinivasan, Krishnapura; Malleshi, Nagappa G

    2010-12-01

    Finger millet (Eleusine coracana) is extensively cultivated and consumed in India and Africa. The millet seed coat is a rich source of dietary fibre and phenolic compounds. The effect of feeding a diet containing 20% finger millet seed coat matter (SCM) was examined in streptozotocin-induced diabetic rats. Diabetic rats maintained on the millet SCM diet (diabetic experimental (DE) group) for 6 weeks exhibited a lesser degree of fasting hyperglycaemia and partial reversal of abnormalities in serum albumin, urea and creatinine compared with the diabetic control (DC) group. The DE group of rats excreted comparatively lesser amounts of glucose, protein, urea and creatinine and was accompanied by improved body weights compared with their corresponding controls. Hypercholesterolaemia and hypertriacylglycerolaemia associated with diabetes were also notably reversed in the DE group. Slit lamp examination of the eye lens revealed an immature subcapsular cataract with mild lenticular opacity in the DE group of rats compared to the mature cataract with significant lenticular opacity and corneal vascularisation in the DC group. Lower activity of lens aldose reductase, serum advanced glycation end products and blood glycosylated Hb levels were observed in the DE group. The millet SCM feeding showed pronounced ameliorating effects on kidney pathology as reflected by near normal glomerular and tubular structures and lower glomerular filtration rate compared with the shrunken glomerulus, tubular vacuolations in the DC group. Thus, the present animal study evidenced the hypoglycaemic, hypocholesterolaemic, nephroprotective and anti-cataractogenic properties of finger millet SCM, suggesting its utility as a functional ingredient in diets for diabetics.

  17. Alterations in Plasma Glucose and Cardiac Antioxidant Enzymes Activity in Streptozotocin-Induced Diabetic Rats: Effects of Trigonella foenum-graecum Extract and Swimming Training.

    Science.gov (United States)

    Haghani, Karimeh; Bakhtiyari, Salar; Doost Mohammadpour, Jafar

    2016-04-01

    Diabetes mellitus is a group of metabolic diseases characterized by chronic hyperglycemia. Trigonella foenum-graecum (fenugreek) and swimming training have previously been reported to have hypoglycemic and antioxidant effects. We aimed to evaluate the effects of swimming training and fenugreek aqueous extract, alone and in combination, on plasma glucose and cardiac antioxidant enzymes activity of streptozotocin-induced diabetes in rats. We divided 70 male Wistar rats equally into 7 groups: diabetic control (DC), healthy control (HC), swimming (S), fenugreek seed extract (1.74 g/kg) (F1), fenugreek seed extract (0.87 g/kg) (F2), swimming + fenugreek seed extract (1.74 g/kg) (SF1), and swimming + fenugreek seed extract (0.87 g/kg) (SF2). We used streptozotocin for the induction of diabetes. Statistical analyses were performed using the statistical program SPSS. We did not detect any significant differences in body weight in the F1, F2, S, SF1 and SF2 groups compared with the DC group (p>0.05). The results also revealed that the hypoglycemic effect of combined swimming and fenugreek was significantly stronger (pswimming could be useful for the treatment of hyperglycemia and cardiac oxidative stress induced by type 1 diabetes mellitus. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

  18. A study of the effect of mother tincture of Syzygium jambolanum on metabolic disorders of Streptozotocin induced diabetic male albino rat

    Directory of Open Access Journals (Sweden)

    Soumyajit Maiti

    2014-01-01

    Results: The study indicated that the treatment of mother tincture of Syzygium jambolanum in diabetic albino rats restored the body weight and significantly controlled the elevated blood glucose level as compared with the untreated group. Levels of glycogen in liver and skeletal muscle tissues were recovered by treatment with Syzygium jambolanum in diabetic rats as compared with the untreated diabetic rats. Levels of serum urea, uric acid and creatinine were increased in diabetic rats significantly as compared with the control group, which were resettled in the control group after treatment with mother tincture of Syzygium jambolanum in diabetic animals. Alongside, significant recovery in the activities of antioxidant enzymes like catalyse, peroxidase and super oxide dismutase, the levels of free radicals generated as bye products in hepatic and renal tissues were also observed in the treatment with mother tincture of Syzygium jambolanum treated diabetic animals with respect to the untreated in diabetic animals. Conclusion: The homoeopathic mother tincture of Syzygium jambolanum has therapeutic effect on metabolic disorders and oxidative injuries in Streptozotocin induced diabetic male albino rats.

  19. Attenuation of Streptozotocin-Induced Lipid Profile Anomalies in the Heart, Brain, and mRNA Expression of HMG-CoA Reductase by Diosgenin in Rats.

    Science.gov (United States)

    Hao, Shuang; Xu, Rihao; Li, Dan; Zhu, Zhicheng; Wang, Tiance; Liu, Kexiang

    2015-07-01

    Diabetes mellitus is associated with significant morbidity and mortality that contributes to pathogenesis of cardiovascular diseases. Diosgenin, a naturally occurring aglycone, is present abundantly in fenugreek. The steroidal saponin is being used as a traditional medicine for diabetes. The present study has investigated the effects of diosgenin on lipid profile in the heart and brain, mRNA expression, and hepatic HMG-CoA reductase (HMGR) activity of streptozotocin-induced diabetic rats. In our study, diosgenin was administered (40 mg/kg b.w.) orally for 45 days to control animals and experimentally induced diabetic rats. The effects of diosgenin on glucose, plasma insulin, cholesterol, triglycerides, free fatty acids, and phospholipids (PLs) in the heart and brain were studied. The levels of glucose, cholesterol, triglycerides, free fatty acids, PLs, and HMGR activity were increased significantly (P rats. Administration of diosgenin to diabetic rats significantly reduced blood glucose, cholesterol, triglycerides, free fatty acids, PLs levels, and also HMGR activity. In addition, the plasma insulin level was increased in diosgenin-treated diabetic rats. The above findings were correlated with histological observations of the heart and brain. The results showed that administration of diosgenin remarkably increased plasma insulin level with absolute reduction of blood glucose, lipid profile, and HMGR level when compared to diabetic control rats. The results have suggested that diosgenin prevents hypercholesterolemia and hepatosteatosis by modulation of enzymatic expression that is associated with cholesterol metabolism.

  20. Antihyperglycemic effect of Sesbania grandiflora seed decoction on streptozotocin-induced diabetic mice: Inflammatory status and the role of interleukin-10

    Science.gov (United States)

    Zamroni, Ahmad; Widjanarko, Simon B.; Rifa'i, Muhaimin; Zubaidah, Elok

    2017-05-01

    Diabetes is one of the fastest growing diseases in the world: its prevalence is estimated to reach 642 million people, or one-tenth of adults will have diabetes by 2040. Traditional herbal exploration and investigation are needed in order to discover medicines that have potential anti-diabetic activity, with no or lower side effects than the medicines clinically used today. In this research, we investigated the anti-hyperglycemic activity of an aqueous decoction of Sesbania grandiflora seeds in streptozotocin-induced diabetic mice, and analyzed the immune responses that occurred during the counter balance process to reach blood glucose homeostasis. Our results revealed that administration of the aqueous decoction (2.5 g/kg BW) could lower the blood glucose levels of diabetic mice from an initial blood glucose level of 435 mg/dl to 213 mg/dl within 18 days of treatment. Analysis of inflammatory markers showed that there was no significant difference in the relative amounts of CD4+CD62L-, CD8+CD62L-, TNF-α or IFN-γ between the experimental groups, which revealed that there were no pro-inflammatory responses involved either in hyperglycemia or in the blood glucose lowering process. On the other hand, an increased amount of interleukin-10 in diabetic mice treated with an S. grandiflora seed decoction indicated a role for IL-10 in maintaining blood glucose homeostasis.

  1. Nigella sativa Relieves the Altered Insulin Receptor Signaling in Streptozotocin-Induced Diabetic Rats Fed with a High-Fat Diet.

    Science.gov (United States)

    Balbaa, Mahmoud; El-Zeftawy, Marwa; Ghareeb, Doaa; Taha, Nabil; Mandour, Abdel Wahab

    2016-01-01

    The black cumin (Nigella sativa) "NS" or the black seeds have many pharmacological activities such as antioxidant, anticarcinogenic, antihypertensive, and antidiabetic properties. In this work, streptozotocin-induced diabetic rats fed with a high-fat diet were treated daily with NS oil (NSO) in order to study the effect on the blood glucose, lipid profile, oxidative stress parameters, and the gene expression of some insulin receptor-induced signaling molecules. This treatment was combined also with some drugs (metformin and glimepiride) and the insulin receptor inhibitor I-OMe-AG538. The administration of NSO significantly induced the gene expression of insulin receptor compared to rats that did not receive NSO. Also, it upregulated the expression of insulin-like growth factor-1 and phosphoinositide-3 kinase, whereas the expression of ADAM-17 was downregulated. The expression of ADAM-17 is corroborated by the analysis of TIMP-3 content. In addition, the NSO significantly reduced blood glucose level, components of the lipid profile, oxidative stress parameters, serum insulin/insulin receptor ratio, and the tumor necrosis factor-α, confirming that NSO has an antidiabetic activity. Thus, the daily NSO treatment in our rat model indicates that NSO has a potential in the management of diabetes as well as improvement of insulin-induced signaling.

  2. Nigella sativa Relieves the Altered Insulin Receptor Signaling in Streptozotocin-Induced Diabetic Rats Fed with a High-Fat Diet

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    Mahmoud Balbaa

    2016-01-01

    Full Text Available The black cumin (Nigella sativa “NS” or the black seeds have many pharmacological activities such as antioxidant, anticarcinogenic, antihypertensive, and antidiabetic properties. In this work, streptozotocin-induced diabetic rats fed with a high-fat diet were treated daily with NS oil (NSO in order to study the effect on the blood glucose, lipid profile, oxidative stress parameters, and the gene expression of some insulin receptor-induced signaling molecules. This treatment was combined also with some drugs (metformin and glimepiride and the insulin receptor inhibitor I-OMe-AG538. The administration of NSO significantly induced the gene expression of insulin receptor compared to rats that did not receive NSO. Also, it upregulated the expression of insulin-like growth factor-1 and phosphoinositide-3 kinase, whereas the expression of ADAM-17 was downregulated. The expression of ADAM-17 is corroborated by the analysis of TIMP-3 content. In addition, the NSO significantly reduced blood glucose level, components of the lipid profile, oxidative stress parameters, serum insulin/insulin receptor ratio, and the tumor necrosis factor-α, confirming that NSO has an antidiabetic activity. Thus, the daily NSO treatment in our rat model indicates that NSO has a potential in the management of diabetes as well as improvement of insulin-induced signaling.

  3. The effects of the sulfonylurea glyburide on glutathione peroxidase, superoxide dismutase and catalase activities in the heart tissue of streptozotocin-induced diabetic rat.

    Science.gov (United States)

    Bukan, N; Sancak, B; Bilgihan, A; Kosova, F; Buğdayci, G; Altan, N

    2004-09-01

    Oxygen free radicals have been suggested to be a contributory factor in diabetes complications. The aim of this study was to examine the effects of glyburide on the antioxidant enzyme activities in the heart tissue of diabetic rats. We investigated the activities of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) in the hearts of both control and streptozotocin-induced diabetic rats. In the heart of diabetic rats, the activity of total superoxide dismutase decreased significantly (p < 0.005), whereas the activity of catalase and glutathione peroxidase increased to a large extent (p < 0.0001 and p = 0.05, respectively) at the end of the fourth week compared with the control group. Glyburide treatment of diabetic rats for 4 weeks corrected the changes observed in diabetic heart. In addition, blood glucose levels of untreated diabetic rats decreased following the glyburide treatment. These results demonstrate that the sulfonylurea glyburide is capable of exerting direct insulin-like effect on heart superoxide dismutase, catalase and glutathione peroxidase activities of diabetic rats in vivo.

  4. Beneficial effects of banana (Musa sp. var. elakki bale) flower and pseudostem on hyperglycemia and advanced glycation end-products (AGEs) in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Bhaskar, Jamuna J; Shobha, Mysore S; Sambaiah, Kari; Salimath, Paramahans V

    2011-09-01

    Diabetes is a chronic health problem and major cause of death in most of the countries. Diet management plays an important role in controlling diabetes and its complications along with insulin and drugs. We have examined the effect of banana (Musa sp. var. elakki bale) flower and pseudostem on hyperglycemia and advanced glycation end-products (AGEs) in streptozotocin-induced diabetic rats. Our results indicated that banana flower and pseudostem have low glycemic index and have a high content of dietary fiber and antioxidants. Diabetic symptoms like hyperglycemia, polyuria, polyphagia, polydipsia, urine sugar, and body weight were ameliorated in banana flower- and pseudostem-treated rats. Increased glomerular filtration rate in the diabetic group (5.1 ± 0.22 ml/min) was decreased in banana flower-fed (2.5 ± 0.37 ml/min) and pseudostem-fed (3.0 ± 0.45 ml/min) groups and were significant at P banana flower- and pseudostem-fed groups, it was reduced to 9.21 ± 0.32 and 9.29 ± 0.24 μg/mg protein, respectively, and were significant at P banana flower and pseudostem have anti-diabetic and anti-AGEs properties and are beneficial as food supplements for diabetics.

  5. Haemato-protective influence of dietary fenugreek (Trigonella foenum-graecum L.) seeds is potentiated by onion (Allium cepa L.) in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Pradeep, Seetur R; Srinivasan, Krishnapura

    2018-02-01

    We have recently reported the beneficial modulation of metabolic abnormalities and oxidative stress in diabetic rats by dietary fenugreek seeds and onion. This investigation evaluated the protective influence of dietary fenugreek seeds (100 g kg -1 ) and onion (30 g kg -1 ) on erythrocytes of streptozotocin-induced diabetic rats, through modulation of reduced haematological indices and antisickling potency. This study also evaluated the altered erythrocyte membrane lipid profile and beneficial countering of increased lipid peroxidation, osmotic fragility, along with reduced membrane fluidity and deformability, nitric oxide production and echinocyte formation. Dietary fenugreek seeds and onion appeared to counter the deformity and fragility of erythrocytes partially in diabetic rats by their antioxidant potential and hypocholesterolemic property. The antisickling potency of these spices was accomplished by a substantial decrease in echinocyte population and AGEs in diabetic rats. Further insight into the factors that might have reduced the fluidity of erythrocytes in diabetic rats revealed changes in the cholesterol: phospholipid ratio, fatty acid profile, and activities of membrane-bound enzymes. Dietary fenugreek seeds and onion offered a beneficial protective effect to the red blood cells, the effect being higher with fenugreek + onion. This is the first report on the hemato-protective influence of a nutraceutical food component in diabetic situation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. Urinary excretion of water-soluble vitamins increases in streptozotocin-induced diabetic rats without decreases in liver or blood vitamin content.

    Science.gov (United States)

    Imai, Eri; Sano, Mitsue; Fukuwatari, Tsutomu; Shibata, Katsumi

    2012-01-01

    It is thought that the contents of water-soluble vitamins in the body are generally low in diabetic patients because large amounts of vitamins are excreted into urine. However, this hypothesis has not been confirmed. To investigate this hypothesis, diabetes was induced in male Wistar rats (6 wk old) by streptozotocin treatment, and they were then given diets containing low, medium or sufficient vitamins for 70 d. The contents of 6 kinds of B-group vitamins, namely vitamin B₁, vitamin B₂, vitamin B₆, vitamin B₁₂, folate and biotin, were determined in the urine, blood and liver. No basic differences among the dietary vitamin contents were observed. The urinary excretion of vitamins was higher in diabetic rats than in control rats. The blood concentrations of vitamin B₁₂ and folate were lowered by diabetes, while, those of vitamin B₁, vitamin B₂, vitamin B₆, and biotin were not. All liver concentrations of vitamins were increased in diabetic rats above those in control rats. These results showed that streptozotocin-induced diabetes increased urinary excretion of water-soluble vitamins, though their blood and liver concentrations were essentially maintained in the rats.

  7. The Effect of N-acetyl-cysteine on Memory Retrieval and the Number of Intact Neurons of Hippocampal CA1 Area in Streptozotocin-induced Alzheimeric Male Rats

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    Niloufar Darbandi

    2018-01-01

    Full Text Available Abstract Background: Alzheimer is a neurodegenerative disease wich caused memory impairment, reduced cognitive functions, intellectual ability and behavior changes. In this study, the effect of N-acetyl-cysteine (NAC as a strong antioxidant on memory deficiency and number of CA1 pyramidal neurons in Streptozotocine (STZ - induced Alzheimeric rats were studied. Materials and Methods: 32 Male Wistar rats were divided into four groups: sham group, streptozotocin group, treated group with streptozotocin plus N-acetyl-cysteine, and treated group with N-acetyl-cysteine alone. Intracerebroventricular (ICV administration of STZ was done in the first and the third day of surgery and i.p injection of N-acetyl-cysteine was done in the fourth of surgery. After the memory test, the animals were killed and their brains were fixed and density of intact neurons in the CA1 area of the hippocampus was investigated. Statistical analysis was performed with software SPSS, ANOVA and Prisme software. The level of statistical significance was set at p 0.05. Conclusion: N-acetyl-cysteine improved memory retrieval and hippocampal CA1 area intact neurons in streptozotocin-induced Alzheimeric male rats.

  8. Neurons in the hippocampal CA1 region, but not the dentate gyrus, are susceptible to oxidative stress in rats with streptozotocin-induced type 1 diabetes

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    Sang Gun Lee

    2015-01-01

    Full Text Available In this study, we investigated the effects of streptozotocin-induced type 1 diabetes on antioxidant-like protein-1 immunoreactivity, protein carbonyl levels, and malondialdehyde formation, a marker for lipid peroxidation, in the hippocampus. For this study, streptozotocin (75 mg/kg was intraperitoneally injected into adult rats to induce type 1 diabetes. The three experimental parameters were determined at 2, 3, 4 weeks after streptozotocin treatment. Fasting blood glucose levels significantly increased by 20.7-21.9 mM after streptozotocin treatment. The number of antioxidant-like protein-1 immunoreactive neurons significantly decreased in the hippocampal CA1 region, but not the dentate gyrus, 3 weeks after streptozotocin treatment compared to the control group. Malondialdehyde and protein carbonyl levels, which are modified by oxidative stress, significantly increased with a peak at 3 weeks after malondialdehyde treatment, and then decreased 4 weeks after malondialdehyde treatment. These results suggest that neurons in the hippocampal CA1 region, but not the dentate gyrus, are susceptible to oxidative stress 3 weeks after malondialdehyde treatment.

  9. The Effects of Lycopene and Insulin on Histological Changes and the Expression Level of Bcl-2 Family Genes in the Hippocampus of Streptozotocin-Induced Diabetic Rats.

    Science.gov (United States)

    Soleymaninejad, Masoume; Joursaraei, Seyed Gholamali; Feizi, Farideh; Jafari Anarkooli, Iraj

    2017-01-01

    The aim of this study was to evaluate the effects of antioxidants lycopene and insulin on histological changes and expression of Bcl-2 family genes in the hippocampus of streptozotocin-induced type 1 diabetic rats. Forty-eight Wistar rats were divided into six groups of control (C), control treated with lycopene (CL), diabetic (D), diabetic treated with insulin (DI), diabetic treated with lycopene (DL), and diabetic treated with insulin and lycopene (DIL). Diabetes was induced by an injection of streptozotocin (60 mg/kg, IP), lycopene (4 mg/kg/day) was given to the lycopene treated groups as gavages, and insulin (Sc, 1-2 U/kg/day) was injected to the groups treated with insulin. The number of hippocampus neurons undergoing cell death in group D had significant differences with groups C and DIL ( p lycopene alone or together reduced the expression of Bax , but increased Bcl-2 and Bcl-x L levels in DI, DL, and DIL rats, especially when compared to group D ( p lycopene contribute to the prevention of cell death by reducing the expression of proapoptotic genes and increasing the expression of antiapoptotic genes in the hippocampus.

  10. Metabolism of phospholipids in peripheral nerve from rats with chronic streptozotocin-induced diabetes: increased turnover of phosphatidylinositol-4,5-bisphosphate

    Energy Technology Data Exchange (ETDEWEB)

    Bell, M E; Peterson, R G; Eichberg, J

    1982-07-01

    The effect of chronic streptozotocin-induced diabetes on phospholipid metabolism in rat sciatic nerve in vitro was investigated. In normal nerve incubated for 2 h in Krebs-Ringer-bicarbonate buffer containing (/sup 32/P)orthophosphate, radioactivity was primarily incorporated into phosphatidylinositol-4,5-bisphosphate and phosphatidylcholine. Smaller amounts were present in phosphatidylinositol-4-phosphate, phosphatidylinositol, and phosphatidic acid. As compared to controls, phosphatidylinositol-4,5-bisphosphate in nerves from animals made diabetic 2, 10, and 20 weeks earlier accounted for 30-46% more of the isotope, expressed as a percentage, incorporated into all phospholipids. In contrast, the proportion of radioactivity in phosphatidylcholine decreased by 10-25%. When the results were expressed as the quantity of phosphorus incorporated into phospholipid, only phosphatidylinositol-4,5-bisphosphate displayed a change. The amount of isotope which entered this lipid increased 60% and 67% for 2- and 10-week diabetic animals, respectively. Increased phosphatidylinositol-4,5-bisphosphate labeling was observed when epineurial-free preparations were used or when the composition of the incubation medium was varied. Sciatic and caudal nerve conduction velocities were decreased after 10 and 20 weeks but were unchanged after 2 weeks. Researchers conclude that an increase in the turnover of phosphatidylinositol-4,5-bisphosphate in sciatic nerve from streptozotocin-diabetic rats appears relatively early and persists throughout the course of the disease. This metabolic alteration may be related to a primary defect responsible for the accompanying deficient peripheral nerve function.

  11. Gastro-Resistant Insulin Receptor-Binding Peptide from Momordica charantia Improved the Glucose Tolerance in Streptozotocin-Induced Diabetic Mice via Insulin Receptor Signaling Pathway.

    Science.gov (United States)

    Lo, Hsin-Yi; Li, Chia-Cheng; Chen, Feng-Yuan; Chen, Jaw-Chyun; Hsiang, Chien-Yun; Ho, Tin-Yun

    2017-10-25

    Momordica charantia is a commonly used food and has been used for the management of diabetes. Our previous study has identified an insulin receptor (IR)-binding protein (mcIRBP) from Momordica charantia. Here we identified the gastro-resistant hypoglycemic bioactive peptides from protease-digested mcIRBP. By in vitro digestion and IR kinase activity assay, we found that a 9-amino-acid-residue peptide, mcIRBP-9, was a gastro-resistant peptide that enhanced IR kinase activities. mcIRBP-9 activated IR signaling transduction pathway, which resulted in the phosphorylation of IR, the translocation of glucose transporter 4, and the uptake of glucose in cells. Intraperitoneal and oral administration of mcIRBP-9 stimulated the glucose clearance by 30.91 ± 0.39% and 32.09 ± 0.38%, respectively, in streptozotocin-induced diabetic mice. Moreover, a pilot study showed that daily ingestion of mcIRBP-9 for 30 days decreased the fasting blood glucose levels and glycated hemoglobin (HbA1c) levels by 23.62 ± 6.14% and 24.06 ± 1.53%, respectively. In conclusion, mcIRBP-9 is a unique gastro-resistant bioactive peptide generated after the digestion of mcIRBP. Furthermore, oral administration of mcIRBP-9 improves both the glucose tolerance and the HbA1c levels in diabetic mice via targeting IR signaling transduction pathway.

  12. Combination therapy of Nigella sativa and human parathyroid hormone on bone mass, biomechanical behavior and structure in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Altan, Mehmet Fatih; Kanter, Mehmet; Donmez, Senayi; Kartal, Murat Emre; Buyukbas, Sadik

    2007-01-01

    Extracts of the seeds of Nigella sativa (NS), an annual herbaceous plant of the Ranunculaceae family, have been used for many years for therapeutic purposes, including their potential anti-diabetic properties. The aim of the present study was to test the hypothesis that combined treatment with NS and human parathyroid hormone (hPTH) is more effective than treatment with NS or hPTH alone in improving bone mass, connectivity, biomechanical behaviour and strength in insulin-dependent diabetic rats. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ) at a single dose of 50mg/kg. The diabetic rats received NS (2ml/kg/day, i.p.), hPTH (6microg/kg/day, i.p.) or NS and hPTH combined for 4 weeks, starting 8 weeks after STZ injection. The beta-cells of the pancreatic islets of Langerhans were examined by immunohistochemical methods. In addition, bone sections of femora were processed for histomorphometry and biomechanical analysis. In diabetic rats, the beta-cells were essentially negative for insulin-immunoreactivity. NS treatment (alone or in combination with hPTH) significantly increased the area of insulin immunoreactive beta-cells in diabetic rats; however, hPTH treatment alone only led to a slightly increase in the insulin-immunoreactivity. These results suggest that NS might be used in a similar manner to insulin as a safe and effective therapy for diabetes and might be useful in the treatment of diabetic osteopenia.

  13. Glucose activates prenyltransferases in pancreatic islet {beta}-cells

    Energy Technology Data Exchange (ETDEWEB)

    Goalstone, Marc [Department of Medicine, University of Colorado, VA Medical Center, Denver, CO 80220 (United States); Kamath, Vasudeva [Department of Pharmaceutical Sciences, Wayne State University, VA Medical Center, Detroit, MI 48201 (United States); Kowluru, Anjaneyulu, E-mail: akowluru@med.wayne.edu [Department of Pharmaceutical Sciences, Wayne State University, VA Medical Center, Detroit, MI 48201 (United States)

    2010-01-01

    A growing body of evidence implicates small G-proteins [e.g., Cdc42 and Rac1] in glucose-stimulated insulin secretion [GSIS] in the islet {beta}-cell. These signaling proteins undergo post-translational modifications [e.g., prenylation] at their C-terminal cysteine residue and appear to be essential for the transport and fusion of insulin-containing secretory granules with the plasma membrane and the exocytotic secretion of insulin. However, potential regulation of the prenylating enzymes by physiological insulin secretogues [e.g., glucose] has not been investigated thus far. Herein, we report immunological localization, sub-cellular distribution and regulation of farnesyltransferases [FTases] and geranylgeranyltransferase [GGTase] by glucose in insulin-secreting INS 832/13 {beta}-cells and normal rat islets. Our findings suggest that an insulinotropic concentration of glucose [20 mM] markedly stimulated the expression of the {alpha}-subunits of FTase/GGTase-1, but not the {beta}-subunits of FTase or GGTase-1 without significantly affecting the predominantly cytosolic distribution of these holoenzymes in INS 832/13 cells and rodent islets. Under these conditions, glucose significantly stimulated [2.5- to 4.0-fold over basal] the activities of both FTase and GGTase-1 in both cell types. Together, these findings provide the first evidence to suggest that GSIS involves activation of the endogenous islet prenyltransferases by glucose, culminating in the activation of their respective G-protein substrates, which is necessary for cytoskeletal rearrangement, vesicular transport, fusion and secretion of insulin.

  14. Lysine deacetylase inhibition prevents diabetes by chromatin-independent immunoregulation and beta-cell protection

    NARCIS (Netherlands)

    Christensen, D.P.; Gysemans, C.; Lundh, M.; Dahllof, M.S.; Noesgaard, D.; Schmidt, S.F.; Mandrup, S; Birkbak, N.; Workman, C.T.; Piemonti, L.; Blaabjerg, L.; Monzani, V.; Fossati, G.; Mascagni, P.; Paraskevas, S.; Aikin, R.A.; Billestrup, N.; Grunnet, L.G.; Dinarello, C.A.; Mathieu, C.; Mandrup-Poulsen, T.

    2014-01-01

    Type 1 diabetes is due to destruction of pancreatic beta-cells. Lysine deacetylase inhibitors (KDACi) protect beta-cells from inflammatory destruction in vitro and are promising immunomodulators. Here we demonstrate that the clinically well-tolerated KDACi vorinostat and givinostat revert diabetes

  15. Regulation of pancreatic beta-cell mass and proliferation by SOCS-3

    DEFF Research Database (Denmark)

    Lindberg, K; Rønn, S G; Tornehave, D

    2005-01-01

    Growth hormone and prolactin are important growth factors for pancreatic beta-cells. The effects exerted by these hormones on proliferation and on insulin synthesis and secretion in beta-cells are largely mediated through the Janus kinase (JAK)/signal transducer and activator of transcription (ST...

  16. What are the potential benefits of clinical beta-cell imaging in diabetes mellitus?

    Science.gov (United States)

    Göke, Burkhard

    2010-05-01

    Previously, studies of the endocrine pancreatic beta-cell were mainly performed ex vivo by morphological means. This data supported the analysis of pathophysiological changes in the pancreatic islet during insults such as diabetes mellitus. Metabolic testing of the pancreatic islet by assaying hormone parameters such als plasma insulin or C-peptide combined with more or less sophisticated calculations allowed conclusions about states of insulin resistance or secretory failure. It also allowed certain correlations of endocrine function with beta-cell mass. Today, with firmer pathophysiological concepts about beta-cell failure, modern protocols of islet transplantation, and drugs on the market coming with promises of preservation or even expansion of beta-cell mass in diabetes mellitus it has become very attractive to search for tools measuring beta-cell mass, if possible even repeatingly in the same organism in vivo. From a clinical point of view, the potential of pancreatic beta-cell mass imaging technologies is looked upon with high expectations. Methodologically, the decisive question is whether it is likely that future beta-cell imaging will provide significant advantages over the metabolic methods already in hand. With new in vivo tools, studies of beta-cell mass and function may offer even new approaches stratifying patients to anti-diabetic therapies.

  17. Serum adipokines as biomarkers of beta-cell function in patients with type 1 diabetes

    DEFF Research Database (Denmark)

    Pham, Minh Nguyet; Kolb, Hubert; Mandrup-Poulsen, Thomas

    2013-01-01

    We investigated the adipokines adiponectin, leptin and resistin as serum biomarkers of beta-cell function in patients with type 1 diabetes.......We investigated the adipokines adiponectin, leptin and resistin as serum biomarkers of beta-cell function in patients with type 1 diabetes....

  18. Pancreatic Beta-Cell Purification by Altering FAD and NAD(PH Metabolism

    Directory of Open Access Journals (Sweden)

    P. de Vos

    2008-07-01

    Full Text Available Isolation of primary beta cells from other cells within in the pancreatic islets is of importance for many fields of islet research. However, up to now, no satisfactory method has been developed that gained high numbers of viable beta cells, without considerable alpha-cell contamination. In this study, we investigated whether rat beta cells can be isolated from nonbeta endocrine cells by manipulating the flavin adenine dinucleotide (FAD and nicotinamide-adenine dinucleotide phosphate (NAD(PH autofluorescence. Beta cells were isolated from dispersed islets by flow cytometry, based on their high FAD and NAD(PH fluorescence. To improve beta cell yield and purity, the cellular FAD and NAD(PH contents were altered by preincubation in culture media containing varying amounts of D-glucose and amino acids. Manipulation of the cellular FAD and NAD(PH fluorescence improves beta cell yield and purity after sorting. This method is also a fast and reliable method to measure beta cell functional viability. A conceivable application is assessing beta cell viability before transplantation.

  19. Lysine deacetylases are produced in pancreatic beta cells and are differentially regulated by proinflammatory cytokines

    DEFF Research Database (Denmark)

    Lundh, M; Christensen, D P; Rasmussen, D N

    2010-01-01

    Cytokine-induced beta cell toxicity is abrogated by non-selective inhibitors of lysine deacetylases (KDACs). The KDAC family consists of 11 members, namely histone deacetylases HDAC1 to HDAC11, but it is not known which KDAC members play a role in cytokine-mediated beta cell death. The aim...

  20. Genotoxicity and fetal abnormality in streptozotocin-induced diabetic rats exposed to cigarette smoke prior to and during pregnancy.

    Science.gov (United States)

    Damasceno, D C; Volpato, G T; Sinzato, Y K; Lima, P H O; Souza, M S S; Iessi, I L; Kiss, A C I; Takaku, M; Rudge, M V C; Calderon, I M P

    2011-10-01

    Maternal hyperglycemia during early pregnancy is associated with increased risk of abnormalities in the offspring. Malformation rates among the offspring of diabetic mothers are 2-5-fold higher than that of the normal population, and congenital malformations are the major cause of mortality and morbidity in the offspring of diabetic mothers. Metabolic changes, such as hyperglycemia and the metabolites obtained from cigarettes both increase the production of reactive oxygen species (ROS) in the embryo or fetus, causing DNA damage. To evaluate the maternal and fetal genotoxicity, and to assess the incidence of fetal anomaly in diabetic female rats exposed to cigarette smoke at different stages of pregnancy in rats. Diabetes was induced by streptozotocin administration and cigarette smoke exposure was produced by a mechanical smoking device that generated mainstream smoke that was delivered into a chamber. Female Wistar rats were randomly assigned to: non-diabetic (ND) and diabetic (D) groups exposed to filtered air; a diabetic group exposed to cigarette smoke prior to and during pregnancy (DS) and a diabetic group only exposed to cigarette smoke prior to pregnancy (DSPP). On pregnancy day 21, blood samples were obtained for DNA damage analysis and fetuses were collected for congenital anomaly assessment. Statistical significance was set at p<0.05 for all analysis. Exposure of diabetic rats to tobacco smoke prior to pregnancy increased fetal DNA damage, but failed to induce teratogenicity. Thus, these results reinforce the importance for women to avoid exposure to cigarette smoke long before they become pregnant. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.

  1. Antioxidant Protective Effect of Glibenclamide and Metformin in Combination with Honey in Pancreas of Streptozotocin-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Omotayo Owomofoyon Erejuwa

    2010-05-01

    Full Text Available Hyperglycemia exerts toxic effects on the pancreatic β-cells. This study investigated the hypothesis that the common antidiabetic drugs glibenclamide and metformin, in combination with tualang honey, offer additional protection for the pancreas of streptozotocin (STZ-induced diabetic rats against oxidative stress and damage. Diabetes was induced in male Sprague Dawley rats by a single dose of STZ (60 mg/kg; ip. Diabetic rats had significantly elevated levels of lipid peroxidation (TBARS, up-regulated activities of superoxide dismutase (SOD and glutathione peroxidase (GPx while catalase (CAT activity was significantly reduced. Glibenclamide and metformin produced no significant effects on TBARS and antioxidant enzymes except GPx in diabetic rats. In contrast, the combination of glibenclamide, metformin and honey significantly up-regulated CAT activity and down-regulated GPx activity while TBARS levels were significantly reduced. These findings suggest that tualang honey potentiates the effect of glibenclamide and metformin to protect diabetic rat pancreas against oxidative stress and damage.

  2. Do post-translational beta cell protein modifications trigger type 1 diabetes?

    DEFF Research Database (Denmark)

    Størling, Joachim; Overgaard, Anne Julie; Brorsson, Caroline Anna

    2013-01-01

    beta cell-specific neo-epitopes. We suggest that the current paradigm of type 1 diabetes as a classical autoimmune disease should be reconsidered since the immune response may not be directed against native beta cell proteins. A modified model for the pathogenetic events taking place in islets leading...... diabetes exists in the published literature. Furthermore, we report that cytokines change the expression levels of several genes encoding proteins involved in PTM processes in human islets, and that there are type 1 diabetes-associated polymorphisms in a number of these. In conclusion, data from...... the literature and presented experimental data support the notion that PTM of beta cell proteins may be involved in triggering beta cell destruction in type 1 diabetes. If the beta cell antigens recognised by the immune system foremost come from modified proteins rather than native ones, the concept of type 1...

  3. Dysregulation of Dicer1 in Beta Cells Impairs Islet Architecture and Glucose Metabolism

    Directory of Open Access Journals (Sweden)

    Amitai D. Mandelbaum

    2012-01-01

    Full Text Available microRNAs (miRNAs play important roles in pancreas development and in regulation of insulin expression in the adult. Here we show that loss of miRNAs activity in beta-cells during embryonic development results in lower beta-cell mass and in impaired glucose tolerance. Dicer1-null cells initially constitute a significant portion of the total beta-cell population. However, during postnatal development, Dicer1-null cells are depleted. Furthermore, wild-type beta cells are repopulating the islets in complex compensatory dynamics. Because loss of Dicer1 is also associated with changes in the distribution of membranous E-cadherin, we hypothesized that E-cadherin activity may play a role in beta cell survival or islet architecture. However, genetic loss of E-cadherin function does not impair islet architecture, suggesting that miRNAs likely function through other or redundant effectors in the endocrine pancreas.

  4. Enhancing pancreatic Beta-cell regeneration in vivo with pioglitazone and alogliptin.

    Directory of Open Access Journals (Sweden)

    Hao Yin

    Full Text Available Pancreatic beta-cells retain limited ability to regenerate and proliferate after various physiologic triggers. Identifying therapies that are able to enhance beta-cell regeneration may therefore be useful for the treatment of both type 1 and type 2 diabetes.In this study we investigated endogenous and transplanted beta-cell regeneration by serially quantifying changes in bioluminescence from beta-cells from transgenic mice expressing firefly luciferase under the control of the mouse insulin I promoter. We tested the ability of pioglitazone and alogliptin, two drugs developed for the treatment of type 2 diabetes, to enhance beta-cell regeneration, and also defined the effect of the immunosuppression with rapamycin and tacrolimus on transplanted islet beta mass.Pioglitazone is a stimulator of nuclear receptor peroxisome proliferator-activated receptor gamma while alogliptin is a selective dipeptidyl peptidase IV inhibitor. Pioglitazone alone, or in combination with alogliptin, enhanced endogenous beta-cell regeneration in streptozotocin-treated mice, while alogliptin alone had modest effects. In a model of syngeneic islet transplantation, immunosuppression with rapamycin and tacrolimus induced an early loss of beta-cell mass, while treatment with insulin implants to maintain normoglycemia and pioglitazone plus alogliptin was able to partially promote beta-cell mass recovery.These data highlight the utility of bioluminescence for serially quantifying functional beta-cell mass in living mice. They also demonstrate the ability of pioglitazone, used either alone or in combination with alogliptin, to enhance regeneration of endogenous islet beta-cells as well as transplanted islets into recipients treated with rapamycin and tacrolimus.

  5. Zinc supplementation alleviates the progression of diabetic nephropathy by inhibiting the overexpression of oxidative-stress-mediated molecular markers in streptozotocin-induced experimental rats.

    Science.gov (United States)

    Barman, Susmita; Pradeep, Seetur R; Srinivasan, Krishnapura

    2018-04-01

    Zinc deficiency during diabetes projects a role for zinc nutrition in the management of diabetic nephropathy. The current study explored whether zinc supplementation protects against diabetic nephropathy through modulation of kidney oxidative stress and stress-induced expression related to the inflammatory process in streptozotocin-induced diabetic rats. Groups of hyperglycemic rats were exposed to dietary interventions for 6 weeks with zinc supplementation (5 times and 10 times the normal level). Supplemental-zinc-fed diabetic groups showed a significant reversal of increased kidney weight and creatinine clearance. There was a significant reduction in hyperlipidemic condition along with improved PUFA:SFA ratio in the renal tissue. Expression of the lipid oxidative marker and expression of inflammatory markers, cytokines, fibrosis factors and apoptotic regulatory proteins observed in diabetic kidney were beneficially modulated by zinc supplementation, the ameliorative effect being concomitant with elevated antiapoptosis. There was a significant reduction in advanced glycation, expression of the receptor of the glycated products and oxidative stress markers. Zinc supplementation countered the higher activity and expression of polyol pathway enzymes in the kidney. Overexpression of the glucose transporters, as an adaptation to the increased need for glucose transport in diabetic condition, was minimized by zinc treatment. The pathological abnormalities in the renal architecture of diabetic animals were corrected by zinc intervention. Thus, dietary zinc supplementation has a significant beneficial effect in the control of diabetic nephropathy. This was exerted through a protective influence on oxidative-stress-induced cytokines, inflammatory proliferation and consequent renal injury. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. GC-MS analysis and screening of antidiabetic, antioxidant and hypolipidemic potential of Cinnamomum tamala oil in streptozotocin induced diabetes mellitus in rats

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    Kumar Suresh

    2012-08-01

    Full Text Available Abstract Aim of the study This study was made to investigate the antidiabetic, antioxidant and hypolipidemic potential of Cinnamomum tamala, (Buch.-Ham. Nees & Eberm (Tejpat oil (CTO in streptozotocin (STZ induced diabetes in rats along with evaluation of chemical constituents. Materials and methods The GC-MS (Gas chromatography–mass spectrometry analysis of the oil showed 31 constituents of which cinnamaldehyde was found the major component (44.898%. CTO and cinnamaldehyde was orally administered to diabetic rats to study its effect in both acute and chronic antihyperglycemic models. The body weight, oral glucose tolerance test and biochemical parameters viz. glucose level, insulin level, liver glycogen content, glycosylated hemoglobin, total plasma cholesterol, triglyceride and antioxidant parameters were estimated for all treated groups and compared against diabetic control group. Results CTO (100 mg/kg and 200 mg/kg, cinnamaldehyde (20 mg/kg and glibenclamide (0.6 mg/kg in respective groups of diabetic animals administered for 28 days reduced the blood glucose level in streptozotocin induced diabetic rats. There was significant increase in body weight, liver glycogen content, plasma insulin level and decrease in the blood glucose, glycosylated hemoglobin and total plasma cholesterol in test groups as compared to control group. The results of CTO and cinnamaldehyde were found comparable with standard drug glibenclamide. In vitro antioxidant studies on CTO using various models showed significant antioxidant activity. In vivo antioxidant studies on STZ induced diabetic rats revealed decreased malondialdehyde (MDA and increased reduced glutathione (GSH. Conclusion Thus the investigation results that CTO has significant antidiabetic, antioxidant and hypolipidemic activity.

  7. Correction of enhanced Na(+)-H+ exchange of rat small intestinal brush-border membranes in streptozotocin-induced diabetes by insulin or 1,25-dihydroxycholecalciferol

    International Nuclear Information System (INIS)

    Dudeja, P.K.; Wali, R.K.; Klitzke, A.; Sitrin, M.D.; Brasitus, T.A.

    1991-01-01

    Diabetes was induced in rats by administration of a single i.p. injection of streptozotocin (50 mg/kg body wt). After 7 d, diabetic rats were further treated with insulin or 1,25-dihydroxycholecalciferol [1,25(OH)2D3] for an additional 5-7 d. Control, diabetic, diabetic + insulin, and diabetic + 1,25(OH)2D3 rats were then killed, their proximal small intestines were removed, and villus-tip epithelial cells were isolated and used to prepare brush-border membrane vesicles. Preparations from each of these groups were then analyzed and compared with respect to their amiloride-sensitive, electroneutral Na(+)-H+ exchange activity, using 22 Na uptake as well as acridine orange techniques. The results of these experiments demonstrated that (a) H+ gradient-dependent 22 Na uptake as well as Na+ gradient-dependent transmembrane H+ fluxes were significantly increased in diabetic vesicles compared to their control counterparts, (b) kinetic studies demonstrated that this enhanced 22 Na uptake in diabetes was a result of increased maximal velocity (Vmax) of this exchanger with no change in apparent affinity (Km) for Na+, (c) serum levels of 1,25(OH)2D3 were significantly lower in diabetic animals compared with their control counterparts; and (d) insulin or 1,25(OH)2D3 treatment restored the Vmax alterations to control values, without any significant changes in Km, concomitant with significantly increasing the serum levels of 1,25(OH)2D3 in diabetic animals. These results indicate that Na(+)-H+ activity is significantly increased in proximal small intestinal luminal membranes of streptozotocin-induced diabetic rats. Moreover, alterations in the serum levels of 1,25(OH)2D3 may, at least in part, explain this enhanced antiporter activity and its correction by insulin

  8. Hypoglycemic, hypolipidemic and antioxidant properties of combination ofCurcumin fromCurcuma longa, Linn, and partially purified product fromAbroma augusta, Linn. in streptozotocin induced diabetes.

    Science.gov (United States)

    Ali Hussain, Halim Eshrat M

    2002-07-01

    Dietary spice components ofCurcuma longa andAbroma augusta have been screened for their protective effect against reactive oxygen species induced lipid peroxidation. They have been found to be efficient antioxidant when administered in combination. The purpose of the study was to investigate the effect of oral administration (300mg/Kg) of the aqueous extract of turmeric whose active ingredient isCurcumin andAbromine powder as a hypoglycemic agent mixed with diet. The effect of this aqueous extract on blood glucose, lipid peroxidation (LPO) and the antioxidant defense system in rat tissues like liver, lung, kidney and brain was studied for 8 weeks in streptozotocin induced diabetic rats. The administration of an aqueous extract of turmeric and abromine powder resulted in a significant reduction in blood glucose and an increase in total haemoglobin. The aqueous extract also resulted in decreased free radical formation in the tissues studied.The decrease in thiobarbituric acid reactive substances (TBARS) and increase in reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) clearly showed the antioxidant property of the mixture. It is suggested that these changes initially counteract the oxidative stress in diabetes however, a gradual decrease in the antioxidative process may be one of the factors which results in chronic diabetes. These results indicate that the mixture of the two plants have shown antidiabetic activity and also reduced oxidative stress in diabetes. A combination ofAbroma augusta and Curcuma longa also restored the other general parameters in diabetic animals. The results were statistically analyzed and indicated that combination of herbal extracts showed better efficacy as compared to individual herbal plant extracts used.

  9. The combined effect of metformin and L-cysteine on inflammation, oxidative stress and insulin resistance in streptozotocin-induced type 2 diabetes in rats.

    Science.gov (United States)

    Salman, Zenat K; Refaat, Rowaida; Selima, Eman; El Sarha, Ashgan; Ismail, Menna A

    2013-08-15

    Increasing evidence has established causative links between obesity, chronic inflammation and insulin resistance; the core pathophysiological feature in type 2 diabetes mellitus. This study was designed to examine whether the combination of L-cysteine and metformin would provide additional benefits in reducing oxidative stress, inflammation and insulin resistance in streptozotocin-induced type 2 diabetes in rats. Male Wistar rats were fed a high-fat diet (HFD) for 8 weeks to induce insulin resistance after which they were rendered diabetic with low-dose streptozotocin. Diabetic rats were treated with metformin (300 mg/kg/day), L-cysteine (300 mg/kg/day) and their combination along with HFD for another 2 weeks. Control rats were fed normal rat chow throughout the experiment. At the end of treatment, fasting blood glucose, fasting serum insulin, homeostasis model assessment-insulin resistance index (HOMA-IR) and serum free fatty acids (FFAs) were measured. Serum levels of the inflammatory markers; monocyte chemoattractant protein-1 (MCP-1), C-reactive protein (CRP) and nitrite/nitrate were also determined. The liver was isolated and used for determination of malondialdehyde (MDA), reduced glutathione (GSH), caspase-3 and cytochrome c levels. The hypoglycemic effect of the combination therapy exceeded that of metformin and L-cysteine monotherapies with more improvement in insulin resistance. All treated groups exhibited significant reductions in serum FFAs, oxidative stress and inflammatory parameters, caspase-3 and cytochrome c levels compared to untreated diabetic rats with the highest improvement observed in the combination group. In conclusion, the present results clearly suggest that L-cysteine can be strongly considered as an adjunct to metformin in management of type 2 diabetes. © 2013 Elsevier B.V. All rights reserved.

  10. Contribution of Musa paradisiaca in the inhibition of α-amylase, α-glucosidase and Angiotensin-I converting enzyme in streptozotocin induced rats.

    Science.gov (United States)

    Shodehinde, Sidiqat A; Ademiluyi, Adedayo O; Oboh, Ganiyu; Akindahunsi, Afolabi A

    2015-07-15

    Unripe plantain based-diets are part of folklore remedy for the management of diabetes in tropical Africa; however, with the dearth of information on the rationale behind this practice; this study therefore, sought to investigate the antihyperglycemic effect of traditional unripe plantain products (Amala and Booli) in high fat fed/low dose streptozotocin-induced diabetic rats and to provide a possible rationale for their antidiabetic properties. Diabetes was induced experimentally by high fat fed/low dose streptozotocin-diabetic rats (25mg/kg body wt.) and the diabetic rats were fed diets supplemented with 20-40% Amala and Booli for 14 days. The effect of the diets on the blood glucose level, pancreatic α-amylase, intestinal α-glucosidase and Angiotensin-I converting enzyme (ACE) activities and plasma antioxidant status as well as amylose/amylopectin content of the unripe plantain products were determined. A marked increase in the blood glucose, α-amylase, α-glucosidase and ACE activities with a corresponding decrease in plasma antioxidant status was recorded in diabetic rats. However, these indices were significantly (P < 0.05) reversed after unripe plantain product supplemented diet treatments for 14 days. Also, the amylose/amylopectin ratio of the products is 1:3. This study revealed that unripe plantain products exert antihyperglycemic effects which could be attributed to the inhibition of α-amylase and α-glucosidase activities by their constituent phytochemicals as well as their amylose/amylopectin contents in the diabetic rats, hence, providing the possible rationale behind their antidiabetic properties. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Diabetic therapeutic effects of ethyl acetate fraction from the roots of Musa paradisiaca and seeds of Eugenia jambolana in streptozotocin-induced male diabetic rats.

    Science.gov (United States)

    Panda, D K; Ghosh, Debidas; Bhat, B; Talwar, S K; Jaggi, M; Mukherjee, R

    2009-11-01

    The folklore medicine of primitive people has been greatly appreciated for centuries. Many researchers study the curative efficiency and mode of action of various medicinal plants. Serum glucose level, lipid profile, glucose tolerance, hepatic and muscle glycogen contents as well as the activities of hepatic hexokinase and glucose-6-phosphatase recovered significantly after oral administration of ethyl acetate fractions of Eugenia jambolana (E. jambolana) or Musa paradisiaca (M. paradisiaca) in separate (E. jambolana L.: 200 mg/kg of body weight and M. paradisiaca: 100 mg/kg of body weight) or combined form for 90 days (twice a day through gavage) to streptozotocin-induced diabetic rats. The loss in body weight of diabetic animals was reversed and serum levels of insulin as well as C-peptide, which were found to be reduced in diabetic rats, increased significantly after oral administration of the fractions. A histological study of the rats' pancreas revealed that after 90 days of oral treatment with the plant fractions in separate or combined form, the size and volume of pancreatic islets in diabetic treated rats increased significantly compared with the diabetic control group. Treatment of diabetic rats with the combined dose (300 mg/kg of body weight) of plant fractions (200 mg E. jambolana and 100 mg M. paradisiaca) was found to be more effective than treatment with the individual fraction. The doses of E. jambolana and M. paradisiaca selected for this study are the optimum antihyperglycemic doses of the plant fractions, which were determined after conducting a dose-dependent study at various dose levels (50-500 mg/kg) in our pilot experiments. The plant fractions were found to be free from metabolic toxicity. Through HPTLC finger printing, three different compounds were noted in the ethyl acetate fraction of E. jambolana L. and eight different compounds in the ethyl acetate fraction of M. paradisiaca L. Copyright 2009 Prous Science, S.A.U. or its licensors. All

  12. Effects of dietary supplementation with docosahexaenoic acid (DHA on hippocampal gene expression in streptozotocin induced diabetic C57Bl/6 mice

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    Jency Thomas

    2015-08-01

    Full Text Available A body of evidence has accumulated indicating diabetes is associated with cognitive impairments. Effective strategies are therefore needed that will delay or prevent the onset of these diabetes-related deficits. In this regard, dietary modification with the naturally occurring compound, docosahexaenoic acid (DHA, holds significant promise as it has been shown to have anti-inflammatory, anti-oxidant, and anti-apoptotic properties. The hippocampus, a limbic structure involved in cognitive functions such as memory formation, is particularly vulnerable to the neurotoxic effects related to diabetes, and we have previously shown that streptozotocin-induced diabetes alters hippocampal gene expression, including genes involved in synaptic plasticity and neurogenesis. In the present study, we explored the effects of dietary supplementation with DHA on hippocampal gene expression in C57Bl/6 diabetic mice. Diabetes was established using streptozotocin (STZ and once stable, the dietary intervention group received AIN93G diet supplemented with DHA (50 mg/kg/day for 6 weeks. Microarray based genome-wide expression analysis was carried out on the hippocampus of DHA supplemented diabetic mice and confirmed by real time polymerase chain reaction (RT-qPCR. Genome-wide analysis identified 353 differentially expressed genes compared to non-supplemented diabetic mice. For example, six weeks of dietary DHA supplementation resulted in increased hippocampal expression of Igf II and Sirt1 and decreased expression of Tnf-α, Il6, Mapkapk2 and ApoE, compared to non-supplemented diabetic mice. Overall, DHA supplementation appears to alter hippocampal gene expression in a way that is consistent with it being neuroprotective in the context of the metabolic and inflammatory insults associated with diabetes.

  13. A Comparison of Food-grade Folium mori Extract and 1-Deoxynojirimycin for Glycemic Control and Renal Function in Streptozotocin-induced Diabetic Rats

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    Shiang-Suo Huang

    2014-07-01

    Full Text Available Folium mori (桑葉 Sāng Yè, leaf of Morus alba L.; FM is known to possess hypoglycemic effects, and 1-deoxynojirimycin (1-DNJ has been proposed as an important functional compound in FM. However, the hypoglycemic activity of purified 1-DNJ has been rarely studied. It is also not known how FM and 1-DNJ affect the development of DM nephropathy. This study compared the antidiabetic effect of a commercial FM product with that of purified 1-DNJ in streptozotocin-induced diabetic rats. Seven days after induction, the diabetic rats were gavaged with FM (1, 3, 10, and 30 mg/kg/day, 1-DNJ (30 mg/kg/day, or vehicle (distilled deionized water; 2 ml/kg/day for 7 days. All doses of FM ameliorated fasting and post-prandial blood glucose concomitantly with an increase in peripheral and pancreatic levels of insulin and improved homeostasis model assessment (HOMA-IR in diabetic rats in a dose-dependent manner. Increased thiobarbituric acid reactive substances (TBARS and nitrate/nitrite levels in the kidney, liver, and muscle of diabetic rats were reversed by all doses of FM. The renal function of the diabetic rats was normalized by all doses of FM, while blood pressure changes were reversed by FM at doses of 3 mg/kg and above. Moreover, most of the above-mentioned parameters were improved by FM at doses of 3 mg/kg and above to a similar extent as that of 1-DNJ. The results showed superior antidiabetic potential of the commercial FM product for glycemic control and protection against the development of diabetic nephropathy.

  14. Ameliorative Effect of Hexane Extract of Phalaris canariensis on High Fat Diet-Induced Obese and Streptozotocin-Induced Diabetic Mice

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    Rosa Martha Perez Gutierrez

    2014-01-01

    Full Text Available Obesity is one of the major factors to increase various disorders like diabetes. The present paper emphasizes study related to the antiobesity effect of Phalaris canariensis seeds hexane extract (Al-H in high-fat diet- (HFD- induced obese CD1 mice and in streptozotocin-induced mild diabetic (MD and severely diabetic (SD mice.AL-H was orally administered to MD and SD mice at a dose of 400 mg/kg once a day for 30 days, and a set of biochemical parameters were studied: glucose, cholesterol, triglycerides, lipid peroxidation, liver and muscle glycogen, ALP, SGOT, SGPT, glucose-6-phosphatase, glucokinase, hexokinase, SOD, CAT, GSH, GPX activities, and the effect on insulin level. HS-H significantly reduced the intake of food and water and body weight loss as well as levels of blood glucose, serum cholesterol, triglyceride, lipoprotein, oxidative stress, showed a protective hepatic effect, and increased HDL-cholesterol, serum insulin in diabetic mice. The mice fed on the high-fat diet and treated with AL-H showed inhibitory activity on the lipid metabolism decreasing body weight and weight of the liver and visceral adipose tissues and cholesterol and triglycerides in the liver. We conclude that AL-H can efficiently reduce serum glucose and inhibit insulin resistance, lipid abnormalities, and oxidative stress in MD and SD mice. Our results demonstrate an antiobesity effect reducing lipid droplet accumulation in the liver, indicating that its therapeutic properties may be due to the interaction plant components soluble in the hexane extract, with any of the multiple targets involved in obesity and diabetes pathogenesis.

  15. Matrix metalloproteinase-2 is downregulated in sciatic nerve by streptozotocin induced diabetes and/or treatment with minocycline: Implications for nerve regeneration

    Science.gov (United States)

    Ali, Sumia; Driscoll, Heather E.; Newton, Victoria L.; Gardiner, Natalie J.

    2014-01-01

    Minocycline is an inhibitor of matrix metalloproteinases (MMPs) and has been shown to have analgesic effects. Whilst increased expression of MMPs is associated with neuropathic pain, MMPs also play crucial roles in Wallerian degeneration and nerve regeneration. In this study we examined the expression of MMP-2, MMP-9 and tissue inhibitor of metalloproteinase (TIMP)-1/-2 in the sciatic nerve of control and streptozotocin-induced diabetic rats treated with either vehicle or minocycline by quantitative PCR and gelatin zymography. We assessed the effects of minocycline on nerve conduction velocity and intraepidermal nerve fibre (IENF) deficits in diabetic neuropathy and investigated the effects of minocycline or MMP-2 on neurite outgrowth from primary cultures of dissociated adult rat sensory neurons. We show that MMP-2 is expressed constitutively in the sciatic nerve in vivo and treatment with minocycline or diabetes leads to downregulation of MMP-2 expression and activity. The functional consequence of this is IENF deficits in minocycline-treated nondiabetic rats and an unsupportive microenvironment for regeneration in diabetes. Minocycline reduces levels of MMP-2 mRNA and nerve growth factor-induced neurite outgrowth. Furthermore, in vivo minocycline treatment reduces preconditioning-induced in vitro neurite outgrowth following a sciatic nerve crush. In contrast, the addition of active MMP-2 facilitates neurite outgrowth in the absence of neurotrophic support and pre-treatment of diabetic sciatic nerve substrata with active MMP-2 promotes a permissive environment for neurite outgrowth. In conclusion we suggest that MMP-2 downregulation may contribute to the regenerative deficits in diabetes. Minocycline treatment also downregulates MMP-2 activity and is associated with inhibitory effects on sensory neurons. Thus, caution should be exhibited with its use as the balance between beneficial and detrimental outcomes may be critical in assessing the benefits of using

  16. Ameliorative Effect of Hexane Extract of Phalaris canariensis on High Fat Diet-Induced Obese and Streptozotocin-Induced Diabetic Mice.

    Science.gov (United States)

    Perez Gutierrez, Rosa Martha; Madrigales Ahuatzi, Diana; Horcacitas, Maria Del Carmen; Garcia Baez, Efren; Cruz Victoria, Teresa; Mota-Flores, Jose Maria

    2014-01-01

    Obesity is one of the major factors to increase various disorders like diabetes. The present paper emphasizes study related to the antiobesity effect of Phalaris canariensis seeds hexane extract (Al-H) in high-fat diet- (HFD-) induced obese CD1 mice and in streptozotocin-induced mild diabetic (MD) and severely diabetic (SD) mice.AL-H was orally administered to MD and SD mice at a dose of 400 mg/kg once a day for 30 days, and a set of biochemical parameters were studied: glucose, cholesterol, triglycerides, lipid peroxidation, liver and muscle glycogen, ALP, SGOT, SGPT, glucose-6-phosphatase, glucokinase, hexokinase, SOD, CAT, GSH, GPX activities, and the effect on insulin level. HS-H significantly reduced the intake of food and water and body weight loss as well as levels of blood glucose, serum cholesterol, triglyceride, lipoprotein, oxidative stress, showed a protective hepatic effect, and increased HDL-cholesterol, serum insulin in diabetic mice. The mice fed on the high-fat diet and treated with AL-H showed inhibitory activity on the lipid metabolism decreasing body weight and weight of the liver and visceral adipose tissues and cholesterol and triglycerides in the liver. We conclude that AL-H can efficiently reduce serum glucose and inhibit insulin resistance, lipid abnormalities, and oxidative stress in MD and SD mice. Our results demonstrate an antiobesity effect reducing lipid droplet accumulation in the liver, indicating that its therapeutic properties may be due to the interaction plant components soluble in the hexane extract, with any of the multiple targets involved in obesity and diabetes pathogenesis.

  17. Long-term streptozotocin-induced diabetes in rats leads to severe damage of brain blood vessels and neurons via enhanced oxidative stress.

    Science.gov (United States)

    Yang, Hongying; Fan, Shourui; Song, Dianping; Wang, Zhuo; Ma, Shungao; Li, Shuqing; Li, Xiaohong; Xu, Mian; Xu, Min; Wang, Xianmo

    2013-02-01

    The aim of this study was to investigate pathophysiological alterations and oxidative stress in various stages of streptozotocin (STZ)‑induced diabetes mellitus (DM) in rats. Male Sprague-Dawley rats (120) were randomized into DM and control groups. Body mass, plasma glucose, glycated hemoglobin (HbA1c), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) levels, as well as aldose reductase (AR) activities, in brain tissue and serum were determined. Electron microscopy was used to observe neuron and vessel changes in the brain. In STZ‑treated rats, blood glucose, low density lipoproteins, triglycerides and total cholesterol levels increased 1.43‑3.0‑fold and high density lipoprotein, HbA1c and insulin sensitivity index increased 1.1‑1.23‑fold compared with control. At week 16 following treatment, DM rat serum H2O2 concentration was increased, indicating oxidative stress and mRNA levels of GPx and SOD were 2‑fold higher than the control. Protein GPx and SOD levels were reduced (PNeuron cells and blood vessels in the DM rat brains became increasingly abnormal over time with altered Golgi bodies, mitochondria and endoplasmic reticulum cisterns, concurrent with SOD inactivation and AR protein accumulation. Disease progression in rats with STZ‑induced DM included brain pathologies with vascular and neuron cell abnormalities, associated with the reduction of SOD, CAT and GPx activities and also AR accumulation.

  18. Beta Cell Mass Restoration in Alloxan-Diabetic Mice Treated with EGF and Gastrin.

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    Imane Song

    Full Text Available One week of treatment with EGF and gastrin (EGF/G was shown to restore normoglycemia and to induce islet regeneration in mice treated with the diabetogenic agent alloxan. The mechanisms underlying this regeneration are not fully understood. We performed genetic lineage tracing experiments to evaluate the contribution of beta cell neogenesis in this model. One day after alloxan administration, mice received EGF/G treatment for one week. The treatment could not prevent the initial alloxan-induced beta cell mass destruction, however it did reverse glycemia to control levels within one day, suggesting improved peripheral glucose uptake. In vitro experiments with C2C12 cell line showed that EGF could stimulate glucose uptake with an efficacy comparable to that of insulin. Subsequently, EGF/G treatment stimulated a 3-fold increase in beta cell mass, which was partially driven by neogenesis and beta cell proliferation as assessed by beta cell lineage tracing and BrdU-labeling experiments, respectively. Acinar cell lineage tracing failed to show an important contribution of acinar cells to the newly formed beta cells. No appearance of transitional cells co-expressing insulin and glucagon, a hallmark for alpha-to-beta cell conversion, was found, suggesting that alpha cells did not significantly contribute to the regeneration. An important fraction of the beta cells significantly lost insulin positivity after alloxan administration, which was restored to normal after one week of EGF/G treatment. Alloxan-only mice showed more pronounced beta cell neogenesis and proliferation, even though beta cell mass remained significantly depleted, suggesting ongoing beta cell death in that group. After one week, macrophage infiltration was significantly reduced in EGF/G-treated group compared to the alloxan-only group. Our results suggest that EGF/G-induced beta cell regeneration in alloxan-diabetic mice is driven by beta cell neogenesis, proliferation and recovery of

  19. Antidiabetic activities of aqueous ethanol and n-butanol fraction of Moringa stenopetala leaves in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Toma, Alemayehu; Makonnen, Eyasu; Mekonnen, Yelamtsehay; Debella, Asfaw; Adisakwattana, Sirichai

    2015-07-18

    Moringa stenopetala has been used in traditional health systems to treat diabetes mellitus. The aim of this study was to investigate the antidiabetic activity of aqueous ethanol and n-butanol fraction of Moringa stenopetala leaves in streptozotocin (STZ) induced diabetic rats. The aqueous ethanol extract and n-butanol fraction of Moringa stenopetala leaves hydroalcoholic (500 mg/kg body weight) and metformin (150 mg/kg body weight) were administered to diabetic rats. Blood glucose, lipid profiles, liver and kidney function were examined after 14 days of experiment. Histopathological profile of the pancreas was also observed in diabetic rats at the end of study. An oral sucrose challenge test was also carried out to assess the post prandial effect of the extract. Oral administration of the aqueous ethanol and n-butanol extracts of Moringa stenopetala leaves (500 mg/kg body weight) and metformin (150 mg/kg) significantly reduced blood glucose level (PMoringa stenopetala leaves possess antihyperglycemic and antihyperlipidemic properties, and alleviate STZ-induced pancreatic damage in diabetic rats. The beneficial effects of plant material in inhibition of diabetes-induced complications are being investigated.

  20. Diosgenin reorganises hyperglycaemia and distorted tissue lipid profile in high-fat diet-streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Naidu, Parim Brahma; Ponmurugan, Ponnusamy; Begum, Mustapha Sabana; Mohan, Karthick; Meriga, Balaji; RavindarNaik, Ramavat; Saravanan, Ganapathy

    2015-12-01

    Diabetes is often connected with significant morbidity, mortality and also has a pivotal role in the development of cardiovascular diseases. Diet intervention, particularly naturaceutical antioxidants have anti-diabetic potential and avert oxidative damage linked with diabetic pathogenesis. The present study investigated the effects of diosgenin, a saponin from fenugreek, on the changes in lipid profile in plasma, liver, heart and brain in high-fat diet-streptozotocin (HFD-STZ)-induced diabetic rats. Diosgenin was administered to HFD-STZ induced diabetic rats by orally at 60 mg kg(-1) body weight for 30 days to assess its effects on body weight gain, glucose, insulin, insulin resistance and cholesterol, triglycerides, free fatty acids and phospholipids in plasma, liver, heart and brain. The levels of body weight, glucose, insulin, insulin resistance, cholesterol, triglycerides, free fatty acids, phospholipids, VLDL-C and LDL-C were increased significantly (P rats. Administration of diosgenin to HFD-STZ diabetic rats caused a decrease in body weight gain, blood glucose, insulin, insulin resistance and also it modulated lipid profile in plasma and tissues. The traditional plant fenugreek and its constituents mediate its anti-diabetic potential through mitigating hyperglycaemic status, altering insulin resistance by alleviating metabolic dysregulation of lipid profile in both plasma and tissues. © 2014 Society of Chemical Industry.

  1. Effects of Dietary Supplementation with Agaricus sylvaticus Schaeffer on Glycemia and Cholesterol after Streptozotocin-Induced Diabetes in Rats

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    Marcelo Betti Mascaro

    2014-01-01

    Full Text Available This study evaluated the effect of the Agaricus sylvaticus (sun mushroom on biochemical tests of the plasma and on the morphology of the pancreas in an experimental model of type I diabetes mellitus (DM1 induced by streptozotocin. One gram of dry A. sylvaticus was homogenized and mixed with the chow. Male Wistar rats were allocated as follows: normoglycemic control that received commercial chow; normoglycemic control group that received chow with A. sylvaticus; diabetic group that received commercial chow; and diabetic group that received chow with A. sylvaticus. Weight, food, and water consumption were measured every two days. Blood glucose levels were measured twice a week. After 30 days, the animals were euthanized and blood was collected for the analysis of cholesterol, HDL, triglycerides, blood sugar, glutamic-pyruvic transaminase (GPT, alkaline phosphatase, iron, transferrin, and urea. The pancreas was processed for microscopic analysis. A. sylvaticus modulated the levels of cholesterol, HDL, triglycerides, blood sugar, GPT, alkaline phosphatase, iron, transferrin, and urea to levels similar to those found in the controls and led to compensatory hyperplasia of the islets of Langerhans. A. sylvaticus is potentially beneficial in the control of type 1 diabetes, and it may also prevent pancreas damage.

  2. Potent effects of the total saponins from Dioscorea nipponica Makino against streptozotocin-induced type 2 diabetes mellitus in rats.

    Science.gov (United States)

    Yu, Hao; Zheng, Lingli; Xu, Lina; Yin, Lianhong; Lin, Yuan; Li, Hua; Liu, Kexin; Peng, Jinyong

    2015-02-01

    The aim of the present paper was to investigate the effects and possible mechanisms of the total saponins from Dioscorea nipponica Makino (TSDN) against type 2 diabetes mellitus. Streptozotocin (STZ) with high-fat diet induced type 2 diabetes mellitus (T2DM) rats were treated with TSDN. Some biochemical parameters, target proteins and genes were investigated. The results showed that TSDN decreased the levels of food/water intake, fasting blood glucose and serum lipid parameters, ameliorated oral glucose and insulin tolerance test levels, markedly increased body weight and serum insulin, reduced excess free radicals and affected ossification and renal protection. Histopathological examination indicated that TSDN increased liver glycogen, decreased the production of lipid vacuoles and lightened liver damage. Further investigation showed that TSDN down-regulated the protein expressions of NF-κB, GRP78, ATF6, eIF2 and the levels of MAPK phosphorylation and up-regulated the protein expressions of IRS-1, GLUT-4, p-Akt and p-AMPK. In addition, TSDN obviously decreased the gene expressions of TNF-a, IL-6, PEPCK, G6Pase, GSK-3β and GSK-3β activity, and increased the gene expressions of PFK, PK and GK activity. These findings show the anti-diabetic activity of total saponins from D. nipponica Makino, which should be developed as a new potent drug for treatment of diabetes mellitus in future. Copyright © 2014 John Wiley & Sons, Ltd.

  3. Neuroprotective effect of Cucumis melo Var. flexuosus leaf extract on the brains of rats with streptozotocin-induced diabetes.

    Science.gov (United States)

    Ibrahim, Doaa S

    2017-02-01

    The central nervous system is one of the most vulnerable organs affected by the oxidative stress associated with diabetes mellitus. Healthy food provides an important source for antioxidants. Therefore, the protective effect of Cucumis melo var. flexuosus (C. melo var. flexuosus) leaf extract on the brains of diabetic rats was investigated. Adult male albino rats divided into 5 groups of 6 rats each were assigned into a normal control group and four diabetic groups. Diabetes was induced in rats by a single intraperitoneal injection of streptozotocin (STZ; 60 mg/kg bw). One of the four diabetic groups was left untreated and was considered as a diabetic control group while the three other groups were treated with C. melo var. flexuosus leaf extract at the doses of 30, 60 and 120 mg/kg bw for a period of 30 days. After completion of experimental duration plasma and brains were used for evaluating biochemical changes. The obtained data showed that C. melo var. flexuosus leaf extract treatment lowered blood glucose, glycated hemoglobin, brain tumor necrosis factor-alpha, interleukin levels, brain malondialdehyde content and caspase-3 activity. Furthermore, the treatment resulted in a marked increase in plasma dopamine, melatonin, brain vascular endothelial growth factor-A levels, brain catalase and superoxide dismutase activities. From the present study, it can be concluded that the C. melo var. flexuosus leaf extract exerts a neuroprotective effect against oxidative damage associated with diabetes.

  4. Anti-diabetic effect of dietary mango (Mangifera indica L.) peel in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Gondi, Mahendranath; Basha, Shaik Akbar; Bhaskar, Jamuna J; Salimath, Paramahans V; Rao, Ummiti J S Prasada

    2015-03-30

    In the present study, the composition of mango peel powder (MPP) collected from the mango pulp industry was determined and the effect of MPP on ameliorating diabetes and its associated complications was studied. Mango peel was rich in polyphenols, carotenoids and dietary fibre. Peel extract contained various bioactive compounds and was found to be rich in soluble dietary fibre. Peel extract exhibited antioxidant properties and protected against DNA damage. Therefore, the effect of peel on ameliorating diabetes was investigated in a rat model of diabetes. A significant increase in urine sugar, urine volume, fasting blood glucose, total cholesterol, triglycerides and low density lipoprotein, and decrease in high density lipoprotein were observed in the rats; however, these parameters were ameliorated in diabetic rats fed with diet supplemented with mango peel at 5% and 10% levels in basal diet. Treatment of diabetic rats with MPP increased antioxidant enzyme activities and decreased lipid peroxidation in plasma, kidney and liver compared to untreated diabetic rats. Glomerular filtration rate and microalbuminuria levels were ameliorated in MPP treated diabetic group. Mango peel, a by-product, can be used as an ingredient in functional and therapeutic foods. © 2014 Society of Chemical Industry.

  5. Chrysin treatment improves diabetes and its complications in liver, brain, and pancreas in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Samarghandian, Saeed; Azimi-Nezhad, Mohsen; Samini, Fariborz; Farkhondeh, Tahereh

    2016-04-01

    Chrysin (CH) is a natural flavonoid with pharmacological influences. The purpose of the current study was the assessment of possible protective effects of CH against oxidative damage in the serum, liver, brain, and pancreas of streptozotocin (STZ)- induced diabetic rats. In the present study, the rats were divided into the following groups of 8 animals each: control, untreated diabetic, 3 CH (20, 40, 80 mg/kg/day)-treated diabetic groups. To find out the modulations of cellular antioxidant defense systems, malondialdehyde (MDA) level and antioxidant enzymes including glutathione-S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT) activities were determined in the serum, liver, brain, and pancreas. STZ caused an elevation of glucose, MDA, TG, TC, LDL-C and with reduction of HDL-C, total protein, SOD, CAT, and GST in the serum, liver, brain, and pancreas (p < 0.01). The findings showed that the significant elevation in the glucose, MDA, TG, TC, LDL-C and reduction of HDL-C, total protein, SOD, CAT, and GST were ameliorated in the CH-treated diabetic groups versus to the untreated groups, in a dose dependent manner (p < 0.05). The current study offers that CH may be recovered diabetes and its complications by modification of oxidative stress.

  6. Pancreatic nitric oxide and oxygen free radicals in the early stages of streptozotocin-induced diabetes mellitus in the rat

    Directory of Open Access Journals (Sweden)

    González E.

    2000-01-01

    Full Text Available The objective of the present study was to explore the regulatory mechanisms of free radicals during streptozotocin (STZ-induced pancreatic damage, which may involve nitric oxide (NO production as a modulator of cellular oxidative stress. Removal of oxygen species by incubating pancreatic tissues in the presence of polyethylene glycol-conjugated superoxide dismutase (PEG-SOD (1 U/ml produced a decrease in nitrite levels (42% and NO synthase (NOS activity (50% in diabetic but not in control samples. When NO production was blocked by N G-monomethyl-L-arginine (L-NMMA (600 µM, SOD activity increased (15.21 ± 1.23 vs 24.40 ± 2.01 U/mg dry weight. The increase was abolished when the NO donor, spermine nonoate, was added to the incubating medium (13.2 ± 1.32. Lipid peroxidation was lower in diabetic tissues when PEG-SOD was added (0.40 ± 0.02 vs 0.20 ± 0.03 nmol/mg protein, and when L-NMMA blocked NOS activity in the incubating medium (0.28 ± 0.05; spermine nonoate (100 µM abolished the decrease in lipoperoxide level (0.70 ± 0.02. We conclude that removal of oxygen species produces a decrease in pancreatic NO and NOS levels in STZ-treated rats. Moreover, inhibition of NOS activity produces an increase in SOD activity and a decrease in lipoperoxidation in diabetic pancreatic tissues. Oxidative stress and NO pathway are related and seem to modulate each other in acute STZ-induced diabetic pancreas in the rat.

  7. Role of Calcium Sensing Receptor in Streptozotocin-Induced Diabetic Rats Exposed to Renal Ischemia Reperfusion Injury

    Directory of Open Access Journals (Sweden)

    Bo Hu

    2018-02-01

    Full Text Available Background/Aims: Renal ischemia/reperfusion (I/R injury (RI/RI is a common complication of diabetes, and it may be involved in altering intracellular calcium concentrations at its onset, which can result in inflammation, abnormal lipid metabolism, the production of reactive oxygen species (ROS, and nitroso-redox imbalance. The calcium-sensing receptor (CaSR is a G-protein coupled receptor, however, the functional involvement of CaSR in diabetic RI/ RI remains unclear. The present study was intended to investigate the role of CaSR on RI/RI in diabetes mellitus (DM. Methods: The bilateral renal arteries and veins of streptozotocin (STZ-induced diabetic rats were subjected to 45-min ischemia followed by 2-h reperfusion with or without R-568 (agonist of CaSR and NPS-2143 (antagonist of CaSR at the beginning of I/R procedure. DM without renal I/R rats served as control group. The expressions of CaSR, calmodulin (CaM, and p47phox in the renal tissue were analyzed by qRT-PCR and Western blot. The renal pathomorphology, renal function, oxidative stress, inflammatory response, and calcium disorder were evaluated by detection of a series of indices by hematoxylin-eosin (HE staining, transmission electron microscope (TEM, commercial kits, enzyme-linked immunosorbent assay (ELISA, and spectrophotofluorometry, respectively. Results: Results showed that the expressions of CaSR, CaM, and p47phox in I/R group were significantly up-regulated as compared with those in DM group, which were accompanied by renal tissue injury, increased calcium, oxidative stress, inflammation, and nitroso-redox imbalance. Conclusion: These results suggest that activation of CaSR is involved in the induction of damage of renal tubular epithelial cell during diabetic RI/RI, resulting in lipid peroxidation, inflammatory response, nitroso-redox imbalance, and apoptosis.

  8. Reduced Expression of the Liver/Beta-Cell Glucose Transporter Isoform in Glucose-Insensitive Pancreatic Beta Cells of Diabetic Rats

    Science.gov (United States)

    Thorens, Bernard; Weir, Gordon C.; Leahy, John L.; Lodish, Harvey F.; Bonner-Weir, Susan

    1990-09-01

    Rats injected with a single dose of streptozocin at 2 days of age develop non-insulin-dependent diabetes 6 weeks later. The pancreatic beta islet cells of these diabetic rats display a loss of glucose-induced insulin secretion while maintaining sensitivity to other secretagogues such as arginine. We analyzed the level of expression of the liver/beta-cell glucose transporter isoform in diabetic islets by immunofluorescence staining of pancreas sections and by Western blotting of islet lysates. Islets from diabetic animals have a reduced expression of this beta-cell-specific glucose transporter isoform and the extent of reduction is correlated with the severity of hyperglycemia. In contrast, expression of this transporter isoform in liver is minimally modified by the diabetes. Thus a decreased expression of the liver/beta-cell glucose transporter isoform in beta cells is associated with the impaired glucose sensing characteristic of diabetic islets; our data suggest that this glucose transporter may be part of the beta-cell glucose sensor.

  9. Osteocalcin protects pancreatic beta cell function and survival under high glucose conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kover, Karen, E-mail: kkover@cmh.edu [Division of Endocrine/Diabetes, Children' s Mercy Hospital & Clinics, Kansas City, MO 64108 (United States); University of Missouri-Kansas City School of Medicine, Kansas City, MO 64108 (United States); Yan, Yun; Tong, Pei Ying; Watkins, Dara; Li, Xiaoyu [Division of Endocrine/Diabetes, Children' s Mercy Hospital & Clinics, Kansas City, MO 64108 (United States); University of Missouri-Kansas City School of Medicine, Kansas City, MO 64108 (United States); Tasch, James; Hager, Melissa [Kansas City University Medical Biosciences, Kansas City, MO (United States); Clements, Mark; Moore, Wayne V. [Division of Endocrine/Diabetes, Children' s Mercy Hospital & Clinics, Kansas City, MO 64108 (United States); University of Missouri-Kansas City School of Medicine, Kansas City, MO 64108 (United States)

    2015-06-19

    Diabetes is characterized by progressive beta cell dysfunction and loss due in part to oxidative stress that occurs from gluco/lipotoxicity. Treatments that directly protect beta cell function and survival in the diabetic milieu are of particular interest. A growing body of evidence suggests that osteocalcin, an abundant non-collagenous protein of bone, supports beta cell function and proliferation. Based on previous gene expression data by microarray, we hypothesized that osteocalcin protects beta cells from glucose-induced oxidative stress. To test our hypothesis we cultured isolated rat islets and INS-1E cells in the presence of normal, high, or high glucose ± osteocalcin for up to 72 h. Oxidative stress and viability/mitochondrial function were measured by H{sub 2}O{sub 2} assay and Alamar Blue assay, respectively. Caspase 3/7 activity was also measured as a marker of apoptosis. A functional test, glucose stimulated insulin release, was conducted and expression of genes/protein was measured by qRT-PCR/western blot/ELISA. Osteocalcin treatment significantly reduced high glucose-induced H{sub 2}O{sub 2} levels while maintaining viability/mitochondrial function. Osteocalcin also significantly improved glucose stimulated insulin secretion and insulin content in rat islets after 48 h of high glucose exposure compared to untreated islets. As expected sustained high glucose down-regulated gene/protein expression of INS1 and BCL2 while increasing TXNIP expression. Interestingly, osteocalcin treatment reversed the effects of high glucose on gene/protein expression. We conclude that osteocalcin can protect beta cells from the negative effects of glucose-induced oxidative stress, in part, by reducing TXNIP expression, thereby preserving beta cell function and survival. - Highlights: • Osteocalcin reduces glucose-induced oxidative stress in beta cells. • Osteocalcin preserves beta cell function and survival under stress conditions. • Osteocalcin reduces glucose

  10. Osteocalcin protects pancreatic beta cell function and survival under high glucose conditions

    International Nuclear Information System (INIS)

    Kover, Karen; Yan, Yun; Tong, Pei Ying; Watkins, Dara; Li, Xiaoyu; Tasch, James; Hager, Melissa; Clements, Mark; Moore, Wayne V.

    2015-01-01

    Diabetes is characterized by progressive beta cell dysfunction and loss due in part to oxidative stress that occurs from gluco/lipotoxicity. Treatments that directly protect beta cell function and survival in the diabetic milieu are of particular interest. A growing body of evidence suggests that osteocalcin, an abundant non-collagenous protein of bone, supports beta cell function and proliferation. Based on previous gene expression data by microarray, we hypothesized that osteocalcin protects beta cells from glucose-induced oxidative stress. To test our hypothesis we cultured isolated rat islets and INS-1E cells in the presence of normal, high, or high glucose ± osteocalcin for up to 72 h. Oxidative stress and viability/mitochondrial function were measured by H 2 O 2 assay and Alamar Blue assay, respectively. Caspase 3/7 activity was also measured as a marker of apoptosis. A functional test, glucose stimulated insulin release, was conducted and expression of genes/protein was measured by qRT-PCR/western blot/ELISA. Osteocalcin treatment significantly reduced high glucose-induced H 2 O 2 levels while maintaining viability/mitochondrial function. Osteocalcin also significantly improved glucose stimulated insulin secretion and insulin content in rat islets after 48 h of high glucose exposure compared to untreated islets. As expected sustained high glucose down-regulated gene/protein expression of INS1 and BCL2 while increasing TXNIP expression. Interestingly, osteocalcin treatment reversed the effects of high glucose on gene/protein expression. We conclude that osteocalcin can protect beta cells from the negative effects of glucose-induced oxidative stress, in part, by reducing TXNIP expression, thereby preserving beta cell function and survival. - Highlights: • Osteocalcin reduces glucose-induced oxidative stress in beta cells. • Osteocalcin preserves beta cell function and survival under stress conditions. • Osteocalcin reduces glucose-induced TXNIP

  11. Effect of environmental enrichment exposure on neuronal morphology of streptozotocin-induced diabetic and stressed rat hippocampus

    Directory of Open Access Journals (Sweden)

    Narendra Pamidi

    2014-08-01

    Full Text Available Background: Environmental enrichment (EE exposure is known to influence the structural changes in the neuronal network of hippocampus. In the present study, we evaluated the effects of EE exposure on the streptozotocin (STZ-induced diabetic and stressed rat hippocampus. Methods: Male albino rats of Wistar strain (4-5 weeks old were grouped into normal control (NC, vehicle control (VC, diabetes (DI, diabetes + stress (DI + S, diabetes + EE (DI + E, and diabetes + stress + EE (DI + S + E groups (n = 8 in each group. Rats were exposed to stress and EE after inducing diabetes with STZ (40 mg/kg. Rats were sacrificed on Day 30 and brain sections were processed for cresyl violet staining to quantify the number of surviving neurons in the CA1, CA3, and dentate hilus (DH regions of hippocampus. Results: A significant (p < 0.001 decrease in the number of survived neurons was noticed in DI (CA1, 34.06 ± 3.2; CA3, 36.1 ± 3.62; DH, 9.83 ± 2.02 as well as DI + S (CA1, 14.03 ± 3.12; CA3, 20.27 ± 4.09; DH, 6.4 ± 1.21 group rats compared to NC rats (CA1, 53.64 ± 2.96; CA3, 62.1 ± 3.34; DH, 21.11 ± 1.03. A significant (p < 0.001 increase in the number of survived neurons was observed in DI + E (CA1, 42.3 ± 3.66; CA3, 46.73 ± 4.74; DH, 17.03 ± 2.19 and DI + S + E (CA1, 29.69 ± 4.47; CA3, 36.73 ± 3.89; DH, 12.23 ± 2.36 group rats compared to DI and DI + S groups, respectively. Conclusions: EE exposure significantly reduced the amount of neuronal damage caused by complications of diabetes and stress to the neurons of hippocampus.

  12. Neuroprotective effect of Quince leaf hydroalcoholic extract on intracerebroventricular streptozotocin-induced oxidative stress in cortical tissue of rat brain

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    A Hajizadeh Moghaddam

    2015-12-01

    in preventing the oxidative damage by increasing the   catalase and superoxide dismutase activity caused by ICV-STZ in cortical tissue of rat brain. Although further studies are needed to clarify the mechanisms of neuroprotective effect of quince leaf, the hydroalcoholic extract seems to partly exert their effects via increasing the antioxidant enzymes activities.

  13. Pancreatic beta-cell lipotoxicity induced by overexpression of hormone-sensitive lipase

    DEFF Research Database (Denmark)

    Winzell, Maria Sörhede; Svensson, Håkan; Enerbäck, Sven

    2003-01-01

    Lipid perturbations associated with triglyceride overstorage in beta-cells impair insulin secretion, a process termed lipotoxicity. To assess the role of hormone-sensitive lipase, which is expressed and enzymatically active in beta-cells, in the development of lipotoxicity, we generated transgenic...... mice overexpressing hormone-sensitive lipase specifically in beta-cells. Transgenic mice developed glucose intolerance and severely blunted glucose-stimulated insulin secretion when challenged with a high-fat diet. As expected, both lipase activity and forskolin-stimulated lipolysis was increased...

  14. The Cytotoxic Role of Intermittent High Glucose on Apoptosis and Cell Viability in Pancreatic Beta Cells

    Directory of Open Access Journals (Sweden)

    Zhen Zhang

    2014-01-01

    Full Text Available Objectives. Glucose fluctuations are both strong predictor of diabetic complications and crucial factor for beta cell damages. Here we investigated the effect of intermittent high glucose (IHG on both cell apoptosis and proliferation activity in INS-1 cells and the potential mechanisms. Methods. Cells were treated with normal glucose (5.5 mmol/L, constant high glucose (CHG (25 mmol/L, and IHG (rotation per 24 h in 11.1 or 25 mmol/L for 7 days. Reactive oxygen species (ROS, xanthine oxidase (XOD level, apoptosis, cell viability, cell cycle, and expression of cyclinD1, p21, p27, and Skp2 were determined. Results. We found that IHG induced more significant apoptosis than CHG and normal glucose; intracellular ROS and XOD levels were more markedly increased in cells exposed to IHG. Cells treated with IHG showed significant decreased cell viability and increased cell proportion in G0/G1 phase. Cell cycle related proteins such as cyclinD1 and Skp2 were decreased significantly, but expressions of p27 and p21 were increased markedly. Conclusions. This study suggested that IHG plays a more toxic effect including both apoptosis-inducing and antiproliferative effects on INS-1 cells. Excessive activation of cellular stress and regulation of cyclins might be potential mechanism of impairment in INS-1 cells induced by IHG.

  15. Effect of aerobic exercise on Pancreas Beta-cells function in adult obese males

    Directory of Open Access Journals (Sweden)

    Mojtaba Eizadi

    2014-08-01

    Conclusion: Aerobic exercise training increases beta cells function and decreases FBS in obese men. These findings support the hypothesis that regular physical activity postpones the occurrence of type 2 diabetes in adult obese subjects.

  16. Protective effects of methane-rich saline on diabetic retinopathy via anti-inflammation in a streptozotocin-induced diabetic rat model

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jiangchun; Wang, Ruobing [Department of Ophthalmology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai (China); Ye, Zhouheng; Sun, Xuejun [Department of Navy Aeromedicine, Second Military Medical University, Shanghai (China); Chen, Zeli; Xia, Fangzhou; Sun, Qinglei [Department of Ophthalmology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai (China); Liu, Lin, E-mail: linliu@sh163.net [Department of Ophthalmology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai (China)

    2015-10-16

    As the commonest complication of diabetes mellitus (DM), diabetic retinopathy (DR) is a neuro-vascular disease with chronic inflammatory. Methane could exert potential therapeutic interest in inflammatory pathologies in previous studies. Our study aims to evaluate the protective effects of methane-rich saline on DR and investigate the potential role of related MicroRNA (miRNA) in diabetic rats. Streptozotocin-induced diabetic Sprague–Dawley rats were injected intraperitoneally with methane-rich or normal saline (5 ml/kg) daily for eight weeks. Morphology changes and blood-retinal barrier (BRB) permeability were assessed by hematoxylin eosin staining and Evans blue leakage. Retinal inflammatory cytokines levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL1-β) were evaluated by immunohistochemistry. Retinal protein expressions of glial fibrillary acidic protein (GFAP) and vascular endothelial growth factor (VEGF) were determined by western blotting. Retinal miRNA expressions were examined by miRNA-specific microarray, verified by quantitative RT-PCR and predicted by GO enrichment and KEGG pathway analysis. There was no significant changes in blood glucose level and body weight of diabetic rats with methane-rich or normal saline treatment, but the decreased retinal thickness, retinal ganglial cell loss and BRB breakdown were all significantly suppressed by methane treatment. DM-induced retinal overexpressions of TNF-α, IL-1β, GFAP and VEGF were also significantly ameliorated. Moreover, the methane treatment significantly up-regulated retinal levels of miR-192-5p (related to apoptosis and tyrosine kinase signaling pathway) and miR-335 (related to proliferation, oxidative stress and leukocyte). Methane exerts protective effect on DR via anti-inflammation, which may be related to the regulatory mechanism of miRNAs. - Highlights: • Methane exerts protective effect on diabetic retinopathy via anti-inflammation. • Therapeutic effect of methane is

  17. Oxidative Stress Parameters and Erythrocyte Membrane Adenosine Triphosphatase Activities in Streptozotocin-induced Diabetic Rats Administered Aqueous Preparation of Kalanchoe Pinnata Leaves.

    Science.gov (United States)

    Menon, Nikhil; Sparks, Jean; Omoruyi, Felix O

    2016-01-01

    Diabetes mellitus is a chronic metabolic disease that according to the World Health Organization affects more than 382 million people. The rise in diabetes mellitus coupled with the lack of an effective treatment has led many to investigate medicinal plants to identify a viable alternative. To evaluate red blood cell (RBC) membrane adenosine triphosphatase (ATPase) activities and antioxidant levels in streptozotocin-induced diabetic rats administered aqueous preparation of Kalanchoe pinnata leaves. Diabetes mellitus was induced in rats by a single administration of streptozotocin (60 mg/kg). Diabetic rats were then treated with aqueous K. pinnata preparation (three mature leaves ~ 9.96 g/70 kg body weight or about 0.14 g/kg body weight/day) for 30 days. Serum glucose, RBC membrane ATPase activities, and antioxidant levels were determined. We noted weight loss and reduced food consumption in the treated diabetic group. Serum glucose levels were reduced in the treated diabetic group compared to the other groups. Superoxide dismutase activity and glutathione levels were not significantly elevated in the treated group compared to the diabetic group. However, serum catalase activity was significantly (P < 0.05) increased in the treated diabetic group compared to the other groups. Serum thiobarbituric acid reactive substances were not significantly altered among the groups. There was a significant (P < 0.05) increase in Mg(2+) ATPase activity and a nonsignificant increase in Na(+)/K(+) ATPase activity in the RBC membrane of the treated diabetic group compared to the diabetic group. The consumption of aqueous preparation of K. pinnata may accrue benefits in the management of diabetes by lowering oxidative stress often associated with the disease and improving the availability of cellular magnesium through an increase in the magnesium ATPase pump in the RBC membrane for increased cellular metabolism of glucose through the glycolytic pathway. We noted weight loss and

  18. Protective effects of methane-rich saline on diabetic retinopathy via anti-inflammation in a streptozotocin-induced diabetic rat model

    International Nuclear Information System (INIS)

    Wu, Jiangchun; Wang, Ruobing; Ye, Zhouheng; Sun, Xuejun; Chen, Zeli; Xia, Fangzhou; Sun, Qinglei; Liu, Lin

    2015-01-01

    As the commonest complication of diabetes mellitus (DM), diabetic retinopathy (DR) is a neuro-vascular disease with chronic inflammatory. Methane could exert potential therapeutic interest in inflammatory pathologies in previous studies. Our study aims to evaluate the protective effects of methane-rich saline on DR and investigate the potential role of related MicroRNA (miRNA) in diabetic rats. Streptozotocin-induced diabetic Sprague–Dawley rats were injected intraperitoneally with methane-rich or normal saline (5 ml/kg) daily for eight weeks. Morphology changes and blood-retinal barrier (BRB) permeability were assessed by hematoxylin eosin staining and Evans blue leakage. Retinal inflammatory cytokines levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL1-β) were evaluated by immunohistochemistry. Retinal protein expressions of glial fibrillary acidic protein (GFAP) and vascular endothelial growth factor (VEGF) were determined by western blotting. Retinal miRNA expressions were examined by miRNA-specific microarray, verified by quantitative RT-PCR and predicted by GO enrichment and KEGG pathway analysis. There was no significant changes in blood glucose level and body weight of diabetic rats with methane-rich or normal saline treatment, but the decreased retinal thickness, retinal ganglial cell loss and BRB breakdown were all significantly suppressed by methane treatment. DM-induced retinal overexpressions of TNF-α, IL-1β, GFAP and VEGF were also significantly ameliorated. Moreover, the methane treatment significantly up-regulated retinal levels of miR-192-5p (related to apoptosis and tyrosine kinase signaling pathway) and miR-335 (related to proliferation, oxidative stress and leukocyte). Methane exerts protective effect on DR via anti-inflammation, which may be related to the regulatory mechanism of miRNAs. - Highlights: • Methane exerts protective effect on diabetic retinopathy via anti-inflammation. • Therapeutic effect of methane is

  19. Evaluation of beta-cell secretory capacity using glucagon-like peptide 1

    DEFF Research Database (Denmark)

    Vilsbøll, Tina; Nielsen, Mette Toft; Krarup, T

    2000-01-01

    Beta-cell secretory capacity is often evaluated with a glucagon test or a meal test. However, glucagon-like peptide 1 (GLP-1) is the most insulinotropic hormone known, and the effect is preserved in type 2 diabetic patients.......Beta-cell secretory capacity is often evaluated with a glucagon test or a meal test. However, glucagon-like peptide 1 (GLP-1) is the most insulinotropic hormone known, and the effect is preserved in type 2 diabetic patients....

  20. Beta-cell lines derived from transgenic mice expressing a hybrid insulin gene-oncogene

    DEFF Research Database (Denmark)

    Efrat, S; Linde, S; Kofod, Hans

    1988-01-01

    Three pancreatic beta-cell lines have been established from insulinomas derived from transgenic mice carrying a hybrid insulin-promoted simian virus 40 tumor antigen gene. The beta tumor cell (beta TC) lines maintain the features of differentiated beta cells for about 50 passages in culture. The ...... both to immortalize a rare cell type and to provide a selection for the maintenance of its differentiated phenotype....

  1. Targeting Cellular Calcium Homeostasis to Prevent Cytokine-Mediated Beta Cell Death.

    Science.gov (United States)

    Clark, Amy L; Kanekura, Kohsuke; Lavagnino, Zeno; Spears, Larry D; Abreu, Damien; Mahadevan, Jana; Yagi, Takuya; Semenkovich, Clay F; Piston, David W; Urano, Fumihiko

    2017-07-17

    Pro-inflammatory cytokines are important mediators of islet inflammation, leading to beta cell death in type 1 diabetes. Although alterations in both endoplasmic reticulum (ER) and cytosolic free calcium levels are known to play a role in cytokine-mediated beta cell death, there are currently no treatments targeting cellular calcium homeostasis to combat type 1 diabetes. Here we show that modulation of cellular calcium homeostasis can mitigate cytokine- and ER stress-mediated beta cell death. The calcium modulating compounds, dantrolene and sitagliptin, both prevent cytokine and ER stress-induced activation of the pro-apoptotic calcium-dependent enzyme, calpain, and partly suppress beta cell death in INS1E cells and human primary islets. These agents are also able to restore cytokine-mediated suppression of functional ER calcium release. In addition, sitagliptin preserves function of the ER calcium pump, sarco-endoplasmic reticulum Ca 2+ -ATPase (SERCA), and decreases levels of the pro-apoptotic protein thioredoxin-interacting protein (TXNIP). Supporting the role of TXNIP in cytokine-mediated cell death, knock down of TXNIP in INS1-E cells prevents cytokine-mediated beta cell death. Our findings demonstrate that modulation of dynamic cellular calcium homeostasis and TXNIP suppression present viable pharmacologic targets to prevent cytokine-mediated beta cell loss in diabetes.

  2. Regulation of Pancreatic Beta Cell Stimulus-Secretion Coupling by microRNAs

    Directory of Open Access Journals (Sweden)

    Jonathan L. S. Esguerra

    2014-11-01

    Full Text Available Increased blood glucose after a meal is countered by the subsequent increased release of the hypoglycemic hormone insulin from the pancreatic beta cells. The cascade of molecular events encompassing the initial sensing and transport of glucose into the beta cell, culminating with the exocytosis of the insulin large dense core granules (LDCVs is termed “stimulus-secretion coupling.” Impairment in any of the relevant processes leads to insufficient insulin release, which contributes to the development of type 2 diabetes (T2D. The fate of the beta cell, when exposed to environmental triggers of the disease, is determined by the possibility to adapt to the new situation by regulation of gene expression. As established factors of post-transcriptional regulation, microRNAs (miRNAs are well-recognized mediators of beta cell plasticity and adaptation. Here, we put focus on the importance of comprehending the transcriptional regulation of miRNAs, and how miRNAs are implicated in stimulus-secretion coupling, specifically those influencing the late stages of insulin secretion. We suggest that efficient beta cell adaptation requires an optimal balance between transcriptional regulation of miRNAs themselves, and miRNA-dependent gene regulation. The increased knowledge of the beta cell transcriptional network inclusive of non-coding RNAs such as miRNAs is essential in identifying novel targets for the treatment of T2D.

  3. CRFR1 is expressed on pancreatic beta cells, promotes beta cell proliferation, and potentiates insulin secretion in a glucose-dependent manner

    DEFF Research Database (Denmark)

    Huising, Mark O; van der Meulen, Talitha; Vaughan, Joan M

    2009-01-01

    Corticotropin-releasing factor (CRF), originally characterized as the principal neuroregulator of the hypothalamus-pituitary-adrenal axis, has broad central and peripheral distribution and actions. We demonstrate the presence of CRF receptor type 1 (CRFR1) on primary beta cells and show that acti...

  4. Suppressor of cytokine signaling 2 (SOCS2) deletion protects against multiple low dose streptozotocin-induced type 1 diabetes in adult male mice

    DEFF Research Database (Denmark)

    Alkharusi, Amira; Mirecki-Garrido, Mercedes; Ma, Zuheng

    2016-01-01

    Background: Diabetes type 1 is characterized by the failure of beta cells to produce insulin. Suppressor of cytokine signaling (SOCS) proteins are important regulators of the Janus kinase/signal transducer and activator of transcription (JAK-STAT) pathway. Previous studies have shown that GH can...... prevent the development of type I diabetes in mice and that SOCS2 deficiency mimics a state of increased GH sensitivity. Methodology: The elevated sensitivity of SOCS2-/- mice to GH and possibly to PRL was the rationale to analyze the effects of multiple low dose streptozotocin (MLDSTZ)-induced diabetes...... in SOCS2-/- mice. Results: We show that 6-month-old SOCS2-/- mice, but not 2-month-old mice, were less sensitive to MLDSTZ-induced diabetes, compared to controls. MLDSTZ treatment induced glucose intolerance in both SOCS2+/+ and SOCS2-/- mice, as shown by glucose tolerance tests, with SOCS2+/+ mice...

  5. Co-culture of clonal beta cells with GLP-1 and glucagon-secreting cell line impacts on beta cell insulin secretion, proliferation and susceptibility to cytotoxins.

    Science.gov (United States)

    Green, Alastair D; Vasu, Srividya; Moffett, R Charlotte; Flatt, Peter R

    2016-06-01

    We investigated the direct effects on insulin releasing MIN6 cells of chronic exposure to GLP-1, glucagon or a combination of both peptides secreted from GLUTag L-cell and αTC1.9 alpha-cell lines in co-culture. MIN6, GLUTag and αTC1.9 cell lines exhibited high cellular hormone content and release of insulin, GLP-1 and glucagon, respectively. Co-culture of MIN6 cells with GLUTag cells significantly increased cellular insulin content, beta-cell proliferation, insulin secretory responses to a range of established secretogogues and afforded protection against exposure cytotoxic concentrations of glucose, lipid, streptozotocin or cytokines. Benefits of co-culture of MIN6 cells with αTC1.9 alphacells were limited to enhanced beta-cell proliferation with marginal positive actions on both insulin secretion and cellular protection. In contrast, co-culture of MIN6 with GLUTag cells plus αTC1.9 cells, markedly enhanced both insulin secretory responses and protection against beta-cell toxins compared with co-culture with GLUTag cells alone. These data indicate important long-term effects of conjoint GLP-1 and glucagon exposure on beta-cell function. This illustrates the possible functional significance of alpha-cell GLP-1 production as well as direct beneficial effects of dual agonism at beta-cell GLP-1 and glucagon receptors. Copyright © 2016 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

  6. Diabetic beta-cells can achieve self-protection against oxidative stress through an adaptive up-regulation of their antioxidant defenses.

    Directory of Open Access Journals (Sweden)

    Grégory Lacraz

    Full Text Available BACKGROUND: Oxidative stress (OS, through excessive and/or chronic reactive oxygen species (ROS, is a mediator of diabetes-related damages in various tissues including pancreatic beta-cells. Here, we have evaluated islet OS status and beta-cell response to ROS using the GK/Par rat as a model of type 2 diabetes. METHODOLOGY/PRINCIPAL FINDINGS: Localization of OS markers was performed on whole pancreases. Using islets isolated from 7-day-old or 2.5-month-old male GK/Par and Wistar control rats, 1 gene expression was analyzed by qRT-PCR; 2 insulin secretion rate was measured; 3 ROS accumulation and mitochondrial polarization were assessed by fluorescence methods; 4 antioxidant contents were quantified by HPLC. After diabetes onset, OS markers targeted mostly peri-islet vascular and inflammatory areas, and not islet cells. GK/Par islets revealed in fact protected against OS, because they maintained basal ROS accumulation similar or even lower than Wistar islets. Remarkably, GK/Par insulin secretion also exhibited strong resistance to the toxic effect of exogenous H(2O(2 or endogenous ROS exposure. Such adaptation was associated to both high glutathione content and overexpression (mRNA and/or protein levels of a large set of genes encoding antioxidant proteins as well as UCP2. Finally, we showed that such a phenotype was not innate but spontaneously acquired after diabetes onset, as the result of an adaptive response to the diabetic environment. CONCLUSIONS: The GK/Par model illustrates the effectiveness of adaptive response to OS by beta-cells to achieve self-tolerance. It remains to be determined to what extend such islet antioxidant defenses upregulation might contribute to GK/Par beta-cell secretory dysfunction.

  7. The effect of smoking cessation pharmacotherapies on pancreatic beta cell function

    International Nuclear Information System (INIS)

    Woynillowicz, Amanda K.; Raha, Sandeep; Nicholson, Catherine J.; Holloway, Alison C.

    2012-01-01

    The goal of our study was to evaluate whether drugs currently used for smoking cessation (i.e., nicotine replacement therapy, varenicline [a partial agonist at nicotinic acetylcholine receptors (nAChR)] and bupropion [which acts in part as a nAChR antagonist]) can affect beta cell function and determine the mechanism(s) of this effect. INS-1E cells, a rat beta cell line, were treated with nicotine, varenicline and bupropion to determine their effects on beta cell function, mitochondrial electron transport chain enzyme activity and cellular/oxidative stress. Treatment of INS-1E cells with equimolar concentrations (1 μM) of three test compounds resulted in an ablation of normal glucose-stimulated insulin secretion by the cells. This disruption of normal beta cell function was associated with mitochondrial dysfunction since all three compounds tested significantly decreased the activity of mitochondrial electron transport chain enzyme activity. These results raise the possibility that the currently available smoking cessation pharmacotherapies may also have adverse effects on beta cell function and thus glycemic control in vivo. Therefore whether or not the use of nicotine replacement therapy, varenicline and bupropion can cause endocrine changes which are consistent with impaired pancreatic function warrants further investigation. -- Highlights: ► Smoking cessation drugs have the potential to disrupt beta cell function in vitro. ► The effects of nicotine, varenicline and bupropion are similar. ► The impaired beta cell function is mediated by mitochondrial dysfunction. ► If similar effects are seen in vivo, these drugs may increase the risk of diabetes.

  8. The effect of smoking cessation pharmacotherapies on pancreatic beta cell function

    Energy Technology Data Exchange (ETDEWEB)

    Woynillowicz, Amanda K. [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Raha, Sandeep [Department of Pediatrics, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Nicholson, Catherine J. [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Holloway, Alison C., E-mail: hollow@mcmaster.ca [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada)

    2012-11-15

    The goal of our study was to evaluate whether drugs currently used for smoking cessation (i.e., nicotine replacement therapy, varenicline [a partial agonist at nicotinic acetylcholine receptors (nAChR)] and bupropion [which acts in part as a nAChR antagonist]) can affect beta cell function and determine the mechanism(s) of this effect. INS-1E cells, a rat beta cell line, were treated with nicotine, varenicline and bupropion to determine their effects on beta cell function, mitochondrial electron transport chain enzyme activity and cellular/oxidative stress. Treatment of INS-1E cells with equimolar concentrations (1 μM) of three test compounds resulted in an ablation of normal glucose-stimulated insulin secretion by the cells. This disruption of normal beta cell function was associated with mitochondrial dysfunction since all three compounds tested significantly decreased the activity of mitochondrial electron transport chain enzyme activity. These results raise the possibility that the currently available smoking cessation pharmacotherapies may also have adverse effects on beta cell function and thus glycemic control in vivo. Therefore whether or not the use of nicotine replacement therapy, varenicline and bupropion can cause endocrine changes which are consistent with impaired pancreatic function warrants further investigation. -- Highlights: ► Smoking cessation drugs have the potential to disrupt beta cell function in vitro. ► The effects of nicotine, varenicline and bupropion are similar. ► The impaired beta cell function is mediated by mitochondrial dysfunction. ► If similar effects are seen in vivo, these drugs may increase the risk of diabetes.

  9. Sustained beta-cell dysfunction but normalized islet mass in aged thrombospondin-1 deficient mice.

    Directory of Open Access Journals (Sweden)

    Carl Johan Drott

    Full Text Available Pancreatic islet endothelial cells have in recent years been shown to support beta-cell mass and function by paracrine interactions. Recently, we identified an islets endothelial-specific glycoprotein, thrombospondin-1 (TSP-1, that showed to be of importance for islet angiogenesis and beta-cell function in young mice. The present study aimed to investigate long-term consequences for islet morphology and beta-cell function of TSP-1 deficiency. Islet and beta-cell mass were observed increased at 10-12 weeks of age in TSP-1 deficient mice, but were normalized before 16 weeks of age when compared to wild-type controls. Islet vascularity was normal in 10-12 and 16-week-old TSP-1 deficient animals, whereas islets of one-year-old animals lacking TSP-1 were hypervascular. Beta-cell dysfunction in TSP-1 deficient animals was present at similar magnitudes between 10-12 and 52 weeks of age, as evaluated by glucose tolerance tests. The insulin secretion capacity in vivo of islets in one-year-old TSP-1 deficient animals was only ∼15% of that in wild-type animals. Using a transplantation model, we reconstituted TSP-1 in adult TSP-deficient islets. In contrast to neonatal TSP-1 deficient islets that we previously reported to regain function after TSP-1 reconstitution, adult islets failed to recover. We conclude that TSP-1 deficiency in islets causes changing vascular and endocrine morphological alterations postnatally, but is coupled to a chronic beta-cell dysfunction. The beta-cell dysfunction induced by TSP-1 deficiency is irreversible if not substituted early in life.

  10. Influence and timing of arrival of murine neural crest on pancreatic beta cell development and maturation.

    Science.gov (United States)

    Plank, Jennifer L; Mundell, Nathan A; Frist, Audrey Y; LeGrone, Alison W; Kim, Thomas; Musser, Melissa A; Walter, Teagan J; Labosky, Patricia A

    2011-01-15

    Interactions between cells from the ectoderm and mesoderm influence development of the endodermally-derived pancreas. While much is known about how mesoderm regulates pancreatic development, relatively little is understood about how and when the ectodermally-derived neural crest regulates pancreatic development and specifically, beta cell maturation. A previous study demonstrated that signals from the neural crest regulate beta cell proliferation and ultimately, beta cell mass. Here, we expand on that work to describe timing of neural crest arrival at the developing pancreatic bud and extend our knowledge of the non-cell autonomous role for neural crest derivatives in the process of beta cell maturation. We demonstrated that murine neural crest entered the pancreatic mesenchyme between the 26 and 27 somite stages (approximately 10.0 dpc) and became intermingled with pancreatic progenitors as the epithelium branched into the surrounding mesenchyme. Using a neural crest-specific deletion of the Forkhead transcription factor Foxd3, we ablated neural crest cells that migrate to the pancreatic primordium. Consistent with previous data, in the absence of Foxd3, and therefore the absence of neural crest cells, proliferation of insulin-expressing cells and insulin-positive area are increased. Analysis of endocrine cell gene expression in the absence of neural crest demonstrated that, although the number of insulin-expressing cells was increased, beta cell maturation was significantly impaired. Decreased MafA and Pdx1 expression illustrated the defect in beta cell maturation; we discovered that without neural crest, there was a reduction in the percentage of insulin-positive cells that co-expressed Glut2 and Pdx1 compared to controls. In addition, transmission electron microscopy analyses revealed decreased numbers of characteristic insulin granules and the presence of abnormal granules in insulin-expressing cells from mutant embryos. Together, these data demonstrate that

  11. A Simple Matter of Life and Death—The Trials of Postnatal Beta-Cell Mass Regulation

    Directory of Open Access Journals (Sweden)

    Elena Tarabra

    2012-01-01

    Full Text Available Pancreatic beta-cells, which secrete the hormone insulin, are the key arbiters of glucose homeostasis. Defective beta-cell numbers and/or function underlie essentially all major forms of diabetes and must be restored if diabetes is to be cured. Thus, the identification of the molecular regulators of beta-cell mass and a better understanding of the processes of beta-cell differentiation and proliferation may provide further insight for the development of new therapeutic targets for diabetes. This review will focus on the principal hormones and nutrients, as well as downstream signalling pathways regulating beta-cell mass in the adult. Furthermore, we will also address more recently appreciated regulators of beta-cell mass, such as microRNAs.

  12. High fat programming of beta cell compensation, exhaustion, death and dysfunction.

    Science.gov (United States)

    Cerf, Marlon E

    2015-03-01

    Programming refers to events during critical developmental windows that shape progeny health outcomes. Fetal programming refers to the effects of intrauterine (in utero) events. Lactational programming refers to the effects of events during suckling (weaning). Developmental programming refers to the effects of events during both fetal and lactational life. Postnatal programming refers to the effects of events either from birth (lactational life) to adolescence or from weaning (end of lactation) to adolescence. Islets are most plastic during the early life course; hence programming during fetal and lactational life is most potent. High fat (HF) programming is the maintenance on a HF diet (HFD) during critical developmental life stages that alters progeny metabolism and physiology. HF programming induces variable diabetogenic phenotypes dependent on the timing and duration of the dietary insult. Maternal obesity reinforces HF programming effects in progeny. HF programming, through acute hyperglycemia, initiates beta cell compensation. However, HF programming eventually leads to chronic hyperglycemia that triggers beta cell exhaustion, death and dysfunction. In HF programming, beta cell dysfunction often co-presents with insulin resistance. Balanced, healthy nutrition during developmental windows is critical for preserving beta cell structure and function. Thus early positive nutritional interventions that coincide with the development of beta cells may reduce the overwhelming burden of diabetes and metabolic disease. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Role of growth factors in control of pancreatic beta cell mass: focus on betatrophin.

    Science.gov (United States)

    Levitsky, Lynne L; Ardestani, Goli; Rhoads, David B

    2014-08-01

    Betatrophin is a newly described hormone, which potently stimulates beta cell replication in mice. This discovery has engendered great hope that it could prove clinically important in the treatment of type 1 and type 2 diabetes. Betatrophin, a 198-amino acid protein secreted by liver and adipose tissue, stimulates growth of pancreatic beta cell mass in insulin-resistant mice. Betatrophin has previously been named RIFL, lipasin, and ANGPLT8, and its salutory effects on lipid metabolism have been described in mouse and human studies. Serum betatrophin levels in humans correlate with improved adipose tissue lipid storage and lower serum triglyceride levels in the fed state, but do not correlate with insulin resistance or carbohydrate tolerance in humans. Betatrophin has not yet been shown to have an effect on beta cell replication in human pancreatic islets. Many endocrine and paracrine factors, of which betatrophin is the newest described, increase beta cell mass in murine models. None of these factors, including betatrophin, have displayed the same activity in clinical studies. This may reflect a profound species difference in beta cell regeneration pathways in mice and humans.

  14. Polymorphisms within novel risk loci for type 2 diabetes determine beta-cell function.

    Directory of Open Access Journals (Sweden)

    Harald Staiger

    Full Text Available BACKGROUND: Type 2 diabetes arises when insulin resistance-induced compensatory insulin secretion exhausts. Insulin resistance and/or beta-cell dysfunction result from the interaction of environmental factors (high-caloric diet and reduced physical activity with a predisposing polygenic background. Very recently, genetic variations within four novel genetic loci (SLC30A8, HHEX, EXT2, and LOC387761 were reported to be more frequent in subjects with type 2 diabetes than in healthy controls. However, associations of these variations with insulin resistance and/or beta-cell dysfunction were not assessed. METHODOLOGY/PRINCIPAL FINDINGS: By genotyping of 921 metabolically characterized German subjects for the reported candidate single nucleotide polymorphisms (SNPs, we show that the major alleles of the SLC30A8 SNP rs13266634 and the HHEX SNP rs7923837 associate with reduced insulin secretion stimulated by orally or intravenously administered glucose, but not with insulin resistance. In contrast, the other reported type 2 diabetes candidate SNPs within the EXT2 and LOC387761 loci did not associate with insulin resistance or beta-cell dysfunction, respectively. CONCLUSIONS/SIGNIFICANCE: The HHEX and SLC30A8 genes encode for proteins that were shown to be required for organogenesis of the ventral pancreas and for insulin maturation/storage, respectively. Therefore, the major alleles of type 2 diabetes candidate SNPs within these genetic loci represent crucial alleles for beta-cell dysfunction and, thus, might confer increased susceptibility of beta-cells towards adverse environmental factors.

  15. New Therapeutic Approaches to Prevent or Delay Beta-Cell Failure in Diabetes

    Directory of Open Access Journals (Sweden)

    Ionica Floriana Elvira

    2015-09-01

    Full Text Available Background and aims: The most recent estimates of International Diabetes Federation indicate that 382 million people have diabetes, and the incidence of this disease is increasing. While in type 1 diabetes mellitus (T1DM beta-cell death is autoimmunemediated, type 2 diabetes mellitus (T2DM results from an interaction between genetic and environmental factors that impair beta-cell function and insulin action. Many people with T2DM remain unaware of their illness for a long time because symptoms may take years to appear or be recognized, while the body is affected by excess blood glucose. These patients are often diagnosed only when diabetes complications have already developed. The aim of this article was to perform a review based on literature data on therapeutic modalities to prevent/delay beta cell function decline. Material and Methods: We searched MEDLINE from 2000 to the present to identify the therapeutic approaches to prevent or delay beta-cell failure in patients with T2DM. Results and conclusions: Several common polymorphisms in genes linked to monogenic forms of diabetes appear to influence the response to T2DM pharmacotherapy. Recent studies report the role of the G protein coupled receptor 40 (GPR40, also known as Free Fatty Acids Receptor 1 (FFAR1 in the regulation of beta-cell function- CNX-011-67 (a GPR40 agonist has the potential to provide good and durable glycemic control in T2DM patients.

  16. Impact of fetal and neonatal environment on beta cell function and development of diabetes

    DEFF Research Database (Denmark)

    Nielsen, Jens H; Haase, Tobias N; Jaksch, Caroline

    2014-01-01

    on the beta cells in both the mother and the fetus and how various conditions like diabetes, obesity, overnutrition and undernutrition during and after pregnancy may influence the ability of the offspring to adapt to changes in insulin demand later in life. The influence of environmental factors including...... that the intrauterine environment during pregnancy has an impact on the gene expression that may persist until adulthood and cause metabolic diseases like obesity and type 2 diabetes. As the pancreatic beta cells are crucial in the regulation of metabolism this article will describe the influence of normal pregnancy...... nutrients and gut microbiota on appetite regulation, mitochondrial activity and the immune system that may affect beta cell growth and function directly and indirectly is discussed. The possible role of epigenetic changes in the transgenerational transmission of the adverse programming may be the most...

  17. Tissue-specific methylation of human insulin gene and PCR assay for monitoring beta cell death.

    Directory of Open Access Journals (Sweden)

    Mohamed I Husseiny

    Full Text Available The onset of metabolic dysregulation in type 1 diabetes (T1D occurs after autoimmune destruction of the majority of pancreatic insulin-producing beta cells. We previously demonstrated that the DNA encoding the insulin gene is uniquely unmethylated in these cells and then developed a methylation-specific PCR (MSP assay to identify circulating beta cell DNA in streptozotocin-treated mice prior to the rise in blood glucose. The current study extends to autoimmune non-obese diabetic (NOD mice and humans, showing in NOD mice that beta cell death occurs six weeks before the rise in blood sugar and coincides with the onset of islet infiltration by immune cells, demonstrating the utility of MSP for monitoring T1D. We previously reported unique patterns of methylation of the human insulin gene, and now extend this to other human tissues. The methylation patterns of the human insulin promoter, intron 1, exon 2, and intron 2 were determined in several normal human tissues. Similar to our previous report, the human insulin promoter was unmethylated in beta cells, but methylated in all other tissues tested. In contrast, intron 1, exon 2 and intron 2 did not exhibit any tissue-specific DNA methylation pattern. Subsequently, a human MSP assay was developed based on the methylation pattern of the insulin promoter and human islet DNA was successfully detected in circulation of T1D patients after islet transplantation therapy. Signal levels of normal controls and pre-transplant samples were shown to be similar, but increased dramatically after islet transplantation. In plasma the signal declines with time but in whole blood remains elevated for at least two weeks, indicating that association of beta cell DNA with blood cells prolongs the signal. This assay provides an effective method to monitor beta cell destruction in early T1D and in islet transplantation therapy.

  18. Insulin-producing cells generated from dedifferentiated human pancreatic beta cells expanded in vitro.

    Directory of Open Access Journals (Sweden)

    Holger A Russ

    Full Text Available Expansion of beta cells from the limited number of adult human islet donors is an attractive prospect for increasing cell availability for cell therapy of diabetes. However, attempts at expanding human islet cells in tissue culture result in loss of beta-cell phenotype. Using a lineage-tracing approach we provided evidence for massive proliferation of beta-cell-derived (BCD cells within these cultures. Expansion involves dedifferentiation resembling epithelial-mesenchymal transition (EMT. Epigenetic analyses indicate that key beta-cell genes maintain open chromatin structure in expanded BCD cells, although they are not transcribed. Here we investigated whether BCD cells can be redifferentiated into beta-like cells.Redifferentiation conditions were screened by following activation of an insulin-DsRed2 reporter gene. Redifferentiated cells were characterized for gene expression, insulin content and secretion assays, and presence of secretory vesicles by electron microscopy. BCD cells were induced to redifferentiate by a combination of soluble factors. The redifferentiated cells expressed beta-cell genes, stored insulin in typical secretory vesicles, and released it in response to glucose. The redifferentiation process involved mesenchymal-epithelial transition, as judged by changes in gene expression. Moreover, inhibition of the EMT effector SLUG (SNAI2 using shRNA resulted in stimulation of redifferentiation. Lineage-traced cells also gave rise at a low rate to cells expressing other islet hormones, suggesting transition of BCD cells through an islet progenitor-like stage during redifferentiation.These findings demonstrate for the first time that expanded dedifferentiated beta cells can be induced to redifferentiate in culture. The findings suggest that ex-vivo expansion of adult human islet cells is a promising approach for generation of insulin-producing cells for transplantation, as well as basic research, toxicology studies, and drug

  19. Determination of Insulin Resistance and Beta Cell Function in Healthy Obese and Non-obese Individuals

    International Nuclear Information System (INIS)

    Kazmi, A.; Sattar, A.; Tariq, K. M.; Najamussahar; Hashim, R.; Almani, M. I.

    2013-01-01

    Objective: To determine insulin resistance and beta cell function in healthy obese and nonobese individuals of the local population. Study Design: Case control study. Place and Duration of Study: AFIP Rawalpindi in collaboration with department of medicine military hospital(MH) Rawalpindi, from Aug 2008 to Mar 2009. Methods: Eighty obese(n=40) and non-obese(n=40) subjects were selected by non-probability convenience sampling. Plasma insulin, glucose, and serum total cholestrol were estimated in fasting state. Insulin resistance was calculated by HOMA-IR and beta cell function by HOMA- equation. Results: Significant differences were observed between obese and non-obese individuals regarding insulin resistance, beta cell function, and BMI and serum total cholesterol. Mean insulin resistance in obese group was found to be 11.1 +- 5.1(range 7.0-16.2) and in non-obese group it was 0.9+-0.4 (range 0.5-1.3). This difference was highly significant (p=0.001). There was a highly significant difference between the two groups in term of beta cell function with mean rank 60.1 for obese group and 20.9 non obese groups (Asym sig. 2 tailed 0.000). Also the correlation (r = 0.064) between insulin resistance and beta cell function in obese group is highly significant (p = 0.000). Mean serum leptin levels were lower (6.3 ng/ml) in non-obese, and high (57.2 ng/ml) in the obese group. Conclusions: Insulin resistance is found higher in obese individuals. Beta cell function is significantly different between obese and non-obese groups. (author)

  20. Effects of ethanol on pancreatic beta-cell death: interaction with glucose and fatty acids.

    Science.gov (United States)

    Dembele, Korami; Nguyen, K Hoa; Hernandez, Tiffany A; Nyomba, B L Grégoire

    2009-04-01

    Western lifestyle plays an important role in the prevalence of type 2 diabetes by causing insulin resistance and pancreatic beta-cell dysfunction, a prerequisite for the development of diabetes. High fat diet and alcohol are major components of the western diet. The aim of the present study was to investigate the effects of ethanol and fatty acids on beta-cell survival and metabolism. We treated the rat beta-cell line RINm5F with ethanol, a mixture of palmitic and oleic acids, or both. Reactive oxygen species (ROS) were determined by (5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate) (CM-H2DCFDA) fluorescence assay, and mitochondrial activity was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) reduction assay and by determining ATP production. Cell viability was assessed with a cell counter and trypan blue exclusion, and the mode of cell death by Hoechst33342 and propidium iodide staining. With both ethanol and fatty acid treatments, MTT reduction and ATP production decreased, whereas ROS production increased. Ethanol treatment had no effect on cell number, whereas fatty acid treatment reduced the cell number. Cell incubation with ethanol, fatty acids, or both increased the number of Hoechst 33342-positive nuclei. However, the majority of nuclei from fatty acid-treated cells were stained with propidium iodide, indicating a loss of plasma membrane integrity. We conclude that both ethanol and fatty acids generate cellular oxidative stress, and affect mitochondrial function in RINm5F beta-cells. However, ethanol causes beta-cell death by apoptosis, whereas fatty acids cause cell death predominantly by necrosis. It is not known whether these results are applicable to human beta-cells.

  1. A human beta cell line with drug inducible excision of immortalizing transgenes

    Science.gov (United States)

    Benazra, Marion; Lecomte, Marie-José; Colace, Claire; Müller, Andreas; Machado, Cécile; Pechberty, Severine; Bricout-Neveu, Emilie; Grenier-Godard, Maud; Solimena, Michele; Scharfmann, Raphaël; Czernichow, Paul; Ravassard, Philippe

    2015-01-01

    Objectives Access to immortalized human pancreatic beta cell lines that are phenotypically close to genuine adult beta cells, represent a major tool to better understand human beta cell physiology and develop new therapeutics for Diabetes. Here we derived a new conditionally immortalized human beta cell line, EndoC-βH3 in which immortalizing transgene can be efficiently removed by simple addition of tamoxifen. Methods We used lentiviral mediated gene transfer to stably integrate a tamoxifen inducible form of CRE (CRE-ERT2) into the recently developed conditionally immortalized EndoC βH2 line. The resulting EndoC-βH3 line was characterized before and after tamoxifen treatment for cell proliferation, insulin content and insulin secretion. Results We showed that EndoC-βH3 expressing CRE-ERT2 can be massively amplified in culture. We established an optimized tamoxifen treatment to efficiently excise the immortalizing transgenes resulting in proliferation arrest. In addition, insulin expression raised by 12 fold and insulin content increased by 23 fold reaching 2 μg of insulin per million cells. Such massive increase was accompanied by enhanced insulin secretion upon glucose stimulation. We further observed that tamoxifen treated cells maintained a stable function for 5 weeks in culture. Conclusions EndoC βH3 cell line represents a powerful tool that allows, using a simple and efficient procedure, the massive production of functional non-proliferative human beta cells. Such cells are close to genuine human beta cells and maintain a stable phenotype for 5 weeks in culture. PMID:26909308

  2. Correction of protein metabolic disorders by composite extract of Musa paradisiaca and Coccinia indica in streptozotocin-induced diabetic albino rat: an approach through the pancreas.

    Science.gov (United States)

    Mallick, Chhanda; De, Debasis; Ghosh, Debidas

    2009-04-01

    The study focused on the ability of the extracts of Musa paradisiaca and Coccinia indica on protein metabolic disorders in streptozotocin (STZ)-induced diabetes. Wistar strain rats were divided into 6 groups as control, control + composite extract treated, STZ-induced diabetes, diabetic + composite extract treated, composite extract-pretreated diabetes, and composite extract-pretreated diabetes + composite extract treated. Protein metabolic status was assessed by serum levels of urea, uric acid, albumin, and creatinine along with urine urea and albumin levels. Diabetic therapeutic ability was assessed by blood glucose, glycated hemoglobin, and serum insulin levels. Histology of the pancreas, liver, and kidney was evaluated. Indices of protein metabolic disorders were deviated from control in STZ-induced diabetes, which were protected significantly after the treatment of composite extract of M. paradisiaca and C. indica. This protection was more prominent when the extract-pretreated animals were subjected to diabetes induction by STZ. The composite extract has a protective therapeutic effect against diabetes through beta-cell regeneration capacity.

  3. Elevated systemic glutamic acid level in the non-obese diabetic mouse is Idd linked and induces beta cell apoptosis.

    Science.gov (United States)

    Banday, Viqar Showkat; Lejon, Kristina

    2017-02-01

    Although type 1 diabetes (T1D) is a T-cell-mediated disease in the effector stage, the mechanism behind the initial beta cell assault is less understood. Metabolomic differences, including elevated levels of glutamic acid, have been observed in patients with T1D before disease onset, as well as in pre-diabetic non-obese diabetic (NOD) mice. Increased levels of glutamic acid damage both neurons and beta cells, implying that this could contribute to the initial events of T1D pathogenesis. We investigated the underlying genetic factors and consequences of the increased levels of glutamic acid in NOD mice. Serum glutamic acid levels from a (NOD×B6)F 2 cohort (n = 182) were measured. By genome-wide and Idd region targeted microsatellite mapping, genetic association was detected for six regions including Idd2, Idd4 and Idd22. In silico analysis of potential enzymes and transporters located in and around the mapped regions that are involved in glutamic acid metabolism consisted of alanine aminotransferase, glutamic-oxaloacetic transaminase, aldehyde dehydrogenase 18 family, alutamyl-prolyl-tRNA synthetase, glutamic acid transporters GLAST and EAAC1. Increased EAAC1 protein expression was observed in lysates from livers of NOD mice compared with B6 mice. Functional consequence of the elevated glutamic acid level in NOD mice was tested by culturing NOD. Rag2 -/- Langerhans' islets with glutamic acid. Induction of apoptosis of the islets was detected upon glutamic acid challenge using TUNEL assay. Our results support the notion that a dysregulated metabolome could contribute to the initiation of T1D. We suggest that targeting of the increased glutamic acid in pre-diabetic patients could be used as a potential therapy. © 2016 John Wiley & Sons Ltd.

  4. The effect of suppressor of cytokine signaling 3 on GH signaling in beta-cells

    DEFF Research Database (Denmark)

    Rønn, Sif G; Hansen, Johnny A; Lindberg, Karen

    2002-01-01

    GH is an important regulator of cell growth and metabolism. In the pancreas, GH stimulates mitogenesis as well as insulin production in beta-cells. The cellular effects of GH are exerted mainly through activation of the Janus kinase-signal transducer and activator of transcription (STAT) pathway...... stable transfection of the beta-cell lines with plasmids expressing SOCS-3 under the control of an inducible promoter, a time- and dose-dependent expression of SOCS-3 in the cells was obtained. EMSA showed that SOCS-3 is able to inhibit GH-induced DNA binding of both STAT3 and STAT5 in RIN-5AH cells...

  5. Planar Cell Polarity Controls Pancreatic Beta Cell Differentiation and Glucose Homeostasis

    DEFF Research Database (Denmark)

    Cortijo, Cedric; Gouzi, Mathieu; Tissir, Fadel

    2012-01-01

    glucose clearance. Loss of Celsr2 and 3 leads to a reduction of Jun phosphorylation in progenitors, which, in turn, reduces beta cell differentiation from endocrine progenitors. These results highlight the importance of the PCP pathway in cell differentiation in vertebrates. In addition, they reveal.......5 synchronously to apicobasal polarization of pancreas progenitors. Loss of function of the two PCP core components Celsr2 and Celsr3 shows that they control the differentiation of endocrine cells from polarized progenitors, with a prevalent effect on insulin-producing beta cells. This results in a decreased...

  6. A standardized method for in vivo mouse pancreas imaging and semiquantitative beta cell mass measurement by dual isotope SPECT

    NARCIS (Netherlands)

    Mathijs, I.; Xavier, C.; Peleman, C.; Caveliers, V.; Brom, M.; Gotthardt, M.; Herrera, P.L.; Lahoutte, T.; Bouwens, L.

    2015-01-01

    PURPOSE: In order to evaluate future beta cell tracers in vivo, we aimed to develop a standardized in vivo method allowing semiquantitative measurement of a prospective beta cell tracer within the pancreas. PROCEDURES: 2-[(123)I]Iodo-L-phenylalanine ([(123)I]IPA) and

  7. Cell specificity of the cytoplasmic Ca2+ response to tolbutamide is impaired in beta-cells from hyperglycemic mice

    DEFF Research Database (Denmark)

    Gustavsson, Natalia; Larsson-Nyrén, Gerd; Lindström, Per

    2006-01-01

    We recently reported that the timing and magnitude of the nutrient-induced Ca(2+) response are specific and reproducible for each isolated beta-cell. We have now used tolbutamide and arginine to test if the cell specificity exists also for the response to non-nutrient stimulation of beta-cells an...

  8. Timing of Ca2+ response in pancreatic beta-cells is related to mitochondrial mass

    DEFF Research Database (Denmark)

    Gustavsson, N; Abedi, G; Larsson-Nyrén, G

    2006-01-01

    timing are disturbed in beta-cells from hyperglycemic mice and one of the causes is likely to be an altered mitochondrial metabolism. Mitochondria play a key role in the control of nutrient-induced insulin secretion. Here, we used confocal microscopy with the fluorescent probe MitoTracker Red CMXRos...

  9. Dual role of proapoptotic BAD in insulin secretion and beta cell survival.

    Science.gov (United States)

    Danial, Nika N; Walensky, Loren D; Zhang, Chen-Yu; Choi, Cheol Soo; Fisher, Jill K; Molina, Anthony J A; Datta, Sandeep Robert; Pitter, Kenneth L; Bird, Gregory H; Wikstrom, Jakob D; Deeney, Jude T; Robertson, Kirsten; Morash, Joel; Kulkarni, Ameya; Neschen, Susanne; Kim, Sheene; Greenberg, Michael E; Corkey, Barbara E; Shirihai, Orian S; Shulman, Gerald I; Lowell, Bradford B; Korsmeyer, Stanley J

    2008-02-01

    The proapoptotic BCL-2 family member BAD resides in a glucokinase-containing complex that regulates glucose-driven mitochondrial respiration. Here, we present genetic evidence of a physiologic role for BAD in glucose-stimulated insulin secretion by beta cells. This novel function of BAD is specifically dependent upon the phosphorylation of its BH3 sequence, previously defined as an essential death domain. We highlight the pharmacologic relevance of phosphorylated BAD BH3 by using cell-permeable, hydrocarbon-stapled BAD BH3 helices that target glucokinase, restore glucose-driven mitochondrial respiration and correct the insulin secretory response in Bad-deficient islets. Our studies uncover an alternative target and function for the BAD BH3 domain and emphasize the therapeutic potential of phosphorylated BAD BH3 mimetics in selectively restoring beta cell function. Furthermore, we show that BAD regulates the physiologic adaptation of beta cell mass during high-fat feeding. Our findings provide genetic proof of the bifunctional activities of BAD in both beta cell survival and insulin secretion.

  10. Oxidative Metabolism Genes Are Not Responsive to Oxidative Stress in Rodent Beta Cell Lines

    Directory of Open Access Journals (Sweden)

    Faer Morrison

    2012-01-01

    Full Text Available Altered expression of oxidative metabolism genes has been described in the skeletal muscle of individuals with type 2 diabetes. Pancreatic beta cells contain low levels of antioxidant enzymes and are particularly susceptible to oxidative stress. In this study, we explored the effect of hyperglycemia-induced oxidative stress on a panel of oxidative metabolism genes in a rodent beta cell line. We exposed INS-1 rodent beta cells to low (5.6 mmol/L, ambient (11 mmol/L, and high (28 mmol/L glucose conditions for 48 hours. Increases in oxidative stress were measured using the fluorescent probe dihydrorhodamine 123. We then measured the expression levels of a panel of 90 oxidative metabolism genes by real-time PCR. Elevated reactive oxygen species (ROS production was evident in INS-1 cells after 48 hours (P<0.05. TLDA analysis revealed a significant (P<0.05 upregulation of 16 of the 90 genes under hyperglycemic conditions, although these expression differences did not reflect differences in ROS. We conclude that although altered glycemia may influence the expression of some oxidative metabolism genes, this effect is probably not mediated by increased ROS production. The alterations to the expression of oxidative metabolism genes previously observed in human diabetic skeletal muscle do not appear to be mirrored in rodent pancreatic beta cells.

  11. Beta cell imaging - a key tool in optimized diabetes prevention and treatment

    NARCIS (Netherlands)

    Gotthardt, M.; Eizirik, D.L.; Cnop, M.; Brom, M.

    2014-01-01

    The prevalence of diabetes is 382 million worldwide, and is expected to rise to 592 million in 2035 (http://www.idf.org/diabetesatlas); 2.5-15\\% of national annual healthcare budgets are related to diabetes care, potentially increasing to 40\\% in high-prevalence countries. Beta cell dysfunction and

  12. MicroRNAs as regulators of beta-cell function and dysfunction

    DEFF Research Database (Denmark)

    Osmai, Mirwais; Osmai, Yama; Bang-Berthelsen, Claus Heiner

    2016-01-01

    , recent studies have demonstrated that miRNAs are important regulators of the islet transcriptome, controlling apoptosis, differentiation and proliferation, as well as regulating unique islet and beta-cell functions and pathways such as insulin expression, processing and secretion. Furthermore, a large...

  13. Effect of iron on pancreatic beta cell function and insulin resistance ...

    African Journals Online (AJOL)

    Background: Increase in total body iron store has been reported in the aetiology and development of diabetes mellitus. The effect of iron supplementation in female with respect to the incidence of diabetes mellitus was investigated on the pancreatic beta cell function and insulin resistance in normal female rats. Methods: ...

  14. Growth hormone is a growth factor for the differentiated pancreatic beta-cell

    DEFF Research Database (Denmark)

    Linde, S; Welinder, B S; Billestrup, N

    1989-01-01

    The regulation of the growth of the pancreatic beta-cell is poorly understood. There are previous indications of a role of GH in the growth and insulin production of the pancreatic islets. In the present study we present evidence for a direct long-term effect of GH on proliferation and insulin...

  15. Cytokines and beta-cell biology: from concept to clinical translation

    DEFF Research Database (Denmark)

    Donath, M.Y.; Storling, J.; Berchtold, L.A.

    2007-01-01

    The tale of cytokines and the beta-cell is a long story, starting with in vitro discovery in 1984, evolving via descriptive and phenomenological studies to detailed mapping of the signalling pathways, gene- and protein expression patterns, molecular and biochemical effector mechanisms to in vivo...

  16. Imaging of beta-Cell Mass and Insulitis in Insulin-Dependent (Type 1) Diabetes Mellitus

    NARCIS (Netherlands)

    Di Gialleonardo, Valentina; de Vries, Erik F. J.; Di Girolamo, Marco; Quintero, Ana M.; Dierckx, Rudi A. J. O.; Signore, Alberto

    2012-01-01

    Insulin-dependent (type 1) diabetes mellitus is a metabolic disease with a complex multifactorial etiology and a poorly understood pathogenesis. Genetic and environmental factors cause an autoimmune reaction against pancreatic beta-cells, called insulitis, confirmed in pancreatic samples obtained at

  17. PDX1, Neurogenin-3, and MAFA: critical transcription regulators for beta cell development and regeneration

    Directory of Open Access Journals (Sweden)

    Yaxi Zhu

    2017-11-01

    Full Text Available Abstract Transcription factors regulate gene expression through binding to specific enhancer sequences. Pancreas/duodenum homeobox protein 1 (PDX1, Neurogenin-3 (NEUROG3, and V-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MAFA are transcription factors critical for beta cell development and maturation. NEUROG3 is expressed in endocrine progenitor cells and controls islet differentiation and regeneration. PDX1 is essential for the development of pancreatic exocrine and endocrine cells including beta cells. PDX1 also binds to the regulatory elements and increases insulin gene transcription. Likewise, MAFA binds to the enhancer/promoter region of the insulin gene and drives insulin expression in response to glucose. In addition to those natural roles in beta cell development and maturation, ectopic expression of PDX1, NEUROG3, and/or MAFA has been successfully used to reprogram various cell types into insulin-producing cells in vitro and in vivo, such as pancreatic exocrine cells, hepatocytes, and pluripotent stem cells. Here, we review biological properties of PDX1, NEUROG3, and MAFA, and their applications and limitations for beta cell regenerative approaches. The primary source literature for this review was acquired using a PubMed search for articles published between 1990 and 2017. Search terms include diabetes, insulin, trans-differentiation, stem cells, and regenerative medicine.

  18. Rac1-NADPH oxidase signaling promotes CD36 activation under glucotoxic conditions in pancreatic beta cells.

    Science.gov (United States)

    Elumalai, Suma; Karunakaran, Udayakumar; Lee, In Kyu; Moon, Jun Sung; Won, Kyu Chang

    2017-04-01

    We recently reported that cluster determinant 36 (CD36), a fatty acid transporter, plays a pivotal role in glucotoxicity-induced β-cell dysfunction. However, little is known about how glucotoxicity influences CD36 expression. Emerging evidence suggests that the small GTPase Rac1 is involved in the pathogenesis of beta cell dysfunction in type 2 diabetes (T2D). The primary objective of the current study was to determine the role of Rac1 in CD36 activation and its impact on β-cell dysfunction in diabetes mellitus. To address this question, we subjected INS-1 cells and human beta cells (1.1B4) to high glucose conditions (30mM) in the presence or absence of Rac1 inhibition either by NSC23766 (Rac1 GTPase inhibitor) or small interfering RNA. High glucose exposure in INS-1 and human beta cells (1.1b4) resulted in the activation of Rac1 and induced cell apoptosis. Rac1 activation mediates NADPH oxidase (NOX) activation leading to elevated ROS production in both cells. Activation of the Rac1-NOX complex by high glucose levels enhanced CD36 expression in INS-1 and human 1.1b4 beta cell membrane fractions. The inhibition of Rac1 by NSC23766 inhibited NADPH oxidase activity and ROS generation induced by high glucose concentrations in INS-1 & human 1.1b4 beta cells. Inhibition of Rac1-NOX complex activation by NSC23766 significantly reduced CD36 expression in INS-1 and human 1.1b4 beta cell membrane fractions. In addition, Rac1 inhibition by NSC23766 significantly reduced high glucose-induced mitochondrial dysfunction. Furthermore, NADPH oxidase inhibition by VAS2870 also attenuated high glucose-induced ROS generation and cell apoptosis. These results suggest that Rac1-NADPH oxidase dependent CD36 expression contributes to high glucose-induced beta cell dysfunction and cell death. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Beta cell 5'-shifted isomiRs are candidate regulatory hubs in type 2 diabetes.

    Directory of Open Access Journals (Sweden)

    Jeanette Baran-Gale

    Full Text Available Next-generation deep sequencing of small RNAs has unveiled the complexity of the microRNA (miRNA transcriptome, which is in large part due to the diversity of miRNA sequence variants ("isomiRs". Changes to a miRNA's seed sequence (nucleotides 2-8, including shifted start positions, can redirect targeting to a dramatically different set of RNAs and alter biological function. We performed deep sequencing of small RNA from mouse insulinoma (MIN6 cells (widely used as a surrogate for the study of pancreatic beta cells and developed a bioinformatic analysis pipeline to profile isomiR diversity. Additionally, we applied the pipeline to recently published small RNA-seq data from primary human beta cells and whole islets and compared the miRNA profiles with that of MIN6. We found that: (1 the miRNA expression profile in MIN6 cells is highly correlated with those of primary human beta cells and whole islets; (2 miRNA loci can generate multiple highly expressed isomiRs with different 5'-start positions (5'-isomiRs; (3 isomiRs with shifted start positions (5'-shifted isomiRs are highly expressed, and can be as abundant as their unshifted counterparts (5'-reference miRNAs. Finally, we identified 10 beta cell miRNA families as candidate regulatory hubs in a type 2 diabetes (T2D gene network. The most significant candidate hub was miR-29, which we demonstrated regulates the mRNA levels of several genes critical to beta cell function and implicated in T2D. Three of the candidate miRNA hubs were novel 5'-shifted isomiRs: miR-375+1, miR-375-1 and miR-183-5p+1. We showed by in silico target prediction and in vitro transfection studies that both miR-375+1 and miR-375-1 are likely to target an overlapping, but distinct suite of beta cell genes compared to canonical miR-375. In summary, this study characterizes the isomiR profile in beta cells for the first time, and also highlights the potential functional relevance of 5'-shifted isomiRs to T2D.

  20. Trans fatty acids increase nitric oxide levels and pancreatic beta-cell necrosis in rats

    Directory of Open Access Journals (Sweden)

    Kusmiyati Tjahjono DK

    2013-04-01

    Full Text Available Background The prevalence of diabetes in Indonesia is increasing due to various factors, including life style changes such as trans fatty acid (TFA intake. High TFA intake is known to be related to blood lipid profile changes resulting in cardiovascular disorders. This study was to identify the effect of TFA on nitric oxide (NO production and on necrosis of pancreatic beta cells. Methods A study of randomized pre-test post–test design with control group. Thirty Sprague Dawley rats were divided into 3 groups, i.e. group K (control, group P1 receiving a diet with 5% TFA, and P2 receiving 10% TFA. The intervention was performed for 8 weeks. NO level and pancreatic beta-cell necrosis were analyzed using Pearson’s chi square test. Results After 4 weeks of treatment there was no change in NO levels in group K, but increased NO in P2 (2.6-3.8 ìM. At 8 weeks after treatment, NO levels in groups P1 and P2 increased to 2.6-3.4 ìM and 4.2-14.3 ìM, respectively, while in group K only 2 rats had increased NO levels of 2.8-2.9 ìM. With Pearson’s chi-square test, there was a signifant difference in the proportions of necrotic pancreatic beta cells after 4 weeks and 8 weeks (p=0.000. No necrosis of beta cells was found in group K, mild necrosis in group P1 (1-25% and moderate necrosis in group P2 (26-50%. Conclusion TFA consumption significantly increases NO levels in Sprague Dawley rats and also results in moderate grades of necrosis of pancreatic beta cells.

  1. Trans fatty acids increase nitric oxide levels and pancreatic beta-cell necrosis in rats

    Directory of Open Access Journals (Sweden)

    Kusmiyati Tjahjono DK

    2015-12-01

    Full Text Available BACKGROUND The prevalence of diabetes in Indonesia is increasing due to various factors, including life style changes such as trans fatty acid (TFA intake. High TFA intake is known to be related to blood lipid profile changes resulting in cardiovascular disorders. This study was to identify the effect of TFA on nitric oxide (NO production and on necrosis of pancreatic beta cells. METHODS A study of randomized pre-test post–test design with control group. Thirty Sprague Dawley rats were divided into 3 groups, i.e. group K (control, group P1 receiving a diet with 5% TFA, and P2 receiving 10% TFA. The intervention was performed for 8 weeks. NO level and pancreatic beta-cell necrosis were analyzed using Pearson’s chi square test. RESULTS After 4 weeks of treatment there was no change in NO levels in group K, but increased NO in P2 (2.6-3.8 ìM. At 8 weeks after treatment, NO levels in groups P1 and P2 increased to 2.6-3.4 ìM and 4.2-14.3 ìM, respectively, while in group K only 2 rats had increased NO levels of 2.8-2.9 ìM. With Pearson’s chi-square test, there was a signifant difference in the proportions of necrotic pancreatic beta cells after 4 weeks and 8 weeks (p= 0.000. No necrosis of beta cells was found in group K, mild necrosis in group P1 (1-25% and moderate necrosis in group P2 (26-50%. CONCLUSION TFA consumption significantly increases NO levels in Sprague Dawley rats and also results in moderate grades of necrosis of pancreatic beta cells

  2. Genetic models rule out a major role of beta cell glycogen in the control of glucose homeostasis.

    Science.gov (United States)

    Mir-Coll, Joan; Duran, Jordi; Slebe, Felipe; García-Rocha, Mar; Gomis, Ramon; Gasa, Rosa; Guinovart, Joan J

    2016-05-01

    Glycogen accumulation occurs in beta cells of diabetic patients and has been proposed to partly mediate glucotoxicity-induced beta cell dysfunction. However, the role of glycogen metabolism in beta cell function and its contribution to diabetes pathophysiology remain poorly understood. We investigated the function of beta cell glycogen by studying glucose homeostasis in mice with (1) defective glycogen synthesis in the pancreas; and (2) excessive glycogen accumulation in beta cells. Conditional deletion of the Gys1 gene and overexpression of protein targeting to glycogen (PTG) was accomplished by Cre-lox recombination using pancreas-specific Cre lines. Glucose homeostasis was assessed by determining fasting glycaemia, insulinaemia and glucose tolerance. Beta cell mass was determined by morphometry. Glycogen was detected histologically by periodic acid-Schiff's reagent staining. Isolated islets were used for the determination of glycogen and insulin content, insulin secretion, immunoblots and gene expression assays. Gys1 knockout (Gys1 (KO)) mice did not exhibit differences in glucose tolerance or basal glycaemia and insulinaemia relative to controls. Insulin secretion and gene expression in isolated islets was also indistinguishable between Gys1 (KO) and controls. Conversely, despite effective glycogen overaccumulation in islets, mice with PTG overexpression (PTG(OE)) presented similar glucose tolerance to controls. However, under fasting conditions they exhibited lower glycaemia and higher insulinaemia. Importantly, neither young nor aged PTG(OE) mice showed differences in beta cell mass relative to age-matched controls. Finally, a high-fat diet did not reveal a beta cell-autonomous phenotype in either model. Glycogen metabolism is not required for the maintenance of beta cell function. Glycogen accumulation in beta cells alone is not sufficient to trigger the dysfunction or loss of these cells, or progression to diabetes.

  3. Hypothyroidism in utero stimulates pancreatic beta cell proliferation and hyperinsulinaemia in the ovine fetus during late gestation.

    Science.gov (United States)

    Harris, Shelley E; De Blasio, Miles J; Davis, Melissa A; Kelly, Amy C; Davenport, Hailey M; Wooding, F B Peter; Blache, Dominique; Meredith, David; Anderson, Miranda; Fowden, Abigail L; Limesand, Sean W; Forhead, Alison J

    2017-06-01

    Thyroid hormones are important regulators of growth and maturation before birth, although the extent to which their actions are mediated by insulin and the development of pancreatic beta cell mass is unknown. Hypothyroidism in fetal sheep induced by removal of the thyroid gland caused asymmetric organ growth, increased pancreatic beta cell mass and proliferation, and was associated with increased circulating concentrations of insulin and leptin. In isolated fetal sheep islets studied in vitro, thyroid hormones inhibited beta cell proliferation in a dose-dependent manner, while high concentrations of insulin and leptin stimulated proliferation. The developing pancreatic beta cell is therefore sensitive to thyroid hormone, insulin and leptin before birth, with possible consequences for pancreatic function in fetal and later life. The findings of this study highlight the importance of thyroid hormones during pregnancy for normal development of the fetal pancreas. Development of pancreatic beta cell mass before birth is essential for normal growth of the fetus and for long-term control of carbohydrate metabolism in postnatal life. Thyroid hormones are also important regulators of fetal growth, and the present study tested the hypotheses that thyroid hormones promote beta cell proliferation in the fetal ovine pancreatic islets, and that growth retardation in hypothyroid fetal sheep is associated with reductions in pancreatic beta cell mass and circulating insulin concentration in utero. Organ growth and pancreatic islet cell proliferation and mass were examined in sheep fetuses following removal of the thyroid gland in utero. The effects of triiodothyronine (T 3 ), insulin and leptin on beta cell proliferation rates were determined in isolated fetal ovine pancreatic islets in vitro. Hypothyroidism in the sheep fetus resulted in an asymmetric pattern of organ growth, pancreatic beta cell hyperplasia, and elevated plasma insulin and leptin concentrations. In pancreatic

  4. In silico identification of NF-kappaB-regulated genes in pancreatic beta-cells

    Directory of Open Access Journals (Sweden)

    Eizirik Decio L

    2007-02-01

    Full Text Available Abstract Background Pancreatic beta-cells are the target of an autoimmune attack in type 1 diabetes mellitus (T1DM. This is mediated in part by cytokines, such as interleukin (IL-1β and interferon (IFN-γ. These cytokines modify the expression of hundreds of genes, leading to beta-cell dysfunction and death by apoptosis. Several of these cytokine-induced genes are potentially regulated by the IL-1β-activated transcription factor (TF nuclear factor (NF-κB, and previous studies by our group have shown that cytokine-induced NF-κB activation is pro-apoptotic in beta-cells. To identify NF-κB-regulated gene networks in beta-cells we presently used a discriminant analysis-based approach to predict NF-κB responding genes on the basis of putative regulatory elements. Results The performance of linear and quadratic discriminant analysis (LDA, QDA in identifying NF-κB-responding genes was examined on a dataset of 240 positive and negative examples of NF-κB regulation, using stratified cross-validation with an internal leave-one-out cross-validation (LOOCV loop for automated feature selection and noise reduction. LDA performed slightly better than QDA, achieving 61% sensitivity, 91% specificity and 87% positive predictive value, and allowing the identification of 231, 251 and 580 NF-κB putative target genes in insulin-producing INS-1E cells, primary rat beta-cells and human pancreatic islets, respectively. Predicted NF-κB targets had a significant enrichment in genes regulated by cytokines (IL-1β or IL-1β + IFN-γ and double stranded RNA (dsRNA, as compared to genes not regulated by these NF-κB-dependent stimuli. We increased the confidence of the predictions by selecting only evolutionary stable genes, i.e. genes with homologs predicted as NF-κB targets in rat, mouse, human and chimpanzee. Conclusion The present in silico analysis allowed us to identify novel regulatory targets of NF-κB using a supervised classification method based on

  5. Early peroxisome proliferator-activated receptor gamma regulated genes involved in expansion of pancreatic beta cell mass

    Directory of Open Access Journals (Sweden)

    Vivas Yurena

    2011-12-01

    Full Text Available Abstract Background The progression towards type 2 diabetes depends on the allostatic response of pancreatic beta cells to synthesise and secrete enough insulin to compensate for insulin resistance. The endocrine pancreas is a plastic tissue able to expand or regress in response to the requirements imposed by physiological and pathophysiological states associated to insulin resistance such as pregnancy, obesity or ageing, but the mechanisms mediating beta cell mass expansion in these scenarios are not well defined. We have recently shown that ob/ob mice with genetic ablation of PPARγ2, a mouse model known as the POKO mouse failed to expand its beta cell mass. This phenotype contrasted with the appropriate expansion of the beta cell mass observed in their obese littermate ob/ob mice. Thus, comparison of these models islets particularly at early ages could provide some new insights on early PPARγ dependent transcriptional responses involved in the process of beta cell mass expansion Results Here we have investigated PPARγ dependent transcriptional responses occurring during the early stages of beta cell adaptation to insulin resistance in wild type, ob/ob, PPARγ2 KO and POKO mice. We have identified genes known to regulate both the rate of proliferation and the survival signals of beta cells. Moreover we have also identified new pathways induced in ob/ob islets that remained unchanged in POKO islets, suggesting an important role for PPARγ in maintenance/activation of mechanisms essential for the continued function of the beta cell. Conclusions Our data suggest that the expansion of beta cell mass observed in ob/ob islets is associated with the activation of an immune response that fails to occur in POKO islets. We have also indentified other PPARγ dependent differentially regulated pathways including cholesterol biosynthesis, apoptosis through TGF-β signaling and decreased oxidative phosphorylation.

  6. Characterization of GLP-1 effects on beta-cell function after meal ingestion in humans

    DEFF Research Database (Denmark)

    Ahrén, Bo; Holst, Jens Juul; Mari, Andrea

    2003-01-01

    OBJECTIVE: Glucagon-like peptide 1 (GLP-1) is an incretin that augments insulin secretion after meal intake and is developed for treatment of type 2 diabetes. As a novel therapeutic agent, characteristics of its beta-cell effects are important to establish. Previously, beta-cell effects of GLP-1...... have been characterized in humans during graded intravenous infusions of glucose, whereas its effects after more physiological stimuli, like meal intake, are not known. RESEARCH DESIGN AND METHODS: Eight women (aged 69 years, fasting glucose 3.7-10.3 mmol/l, BMI 22.4-43.9 kg/m(2)) who had fasted...... meal augments insulin secretion in humans by a dose...

  7. Targeting dysfunctional beta-cell signaling for the potential treatment of type 1 diabetes mellitus.

    Science.gov (United States)

    Fenske, Rachel J; Kimple, Michelle E

    2018-03-01

    Since its discovery and purification by Frederick Banting in 1921, exogenous insulin has remained almost the sole therapy for type 1 diabetes mellitus. While insulin alleviates the primary dysfunction of the disease, many other aspects of the pathophysiology of type 1 diabetes mellitus are unaffected. Research aimed towards the discovery of novel type 1 diabetes mellitus therapeutics targeting different cell signaling pathways is gaining momentum. The focus of these efforts has been almost entirely on the impact of immunomodulatory drugs, particularly those that have already received FDA-approval for other autoimmune diseases. However, these drugs can often have severe side effects, while also putting already immunocompromised individuals at an increased risk for other infections. Potential therapeutic targets in the insulin-producing beta-cell have been largely ignored by the type 1 diabetes mellitus field, save the glucagon-like peptide 1 receptor. While there is preliminary evidence to support the clinical exploration of glucagon-like peptide 1 receptor-based drugs as type 1 diabetes mellitus adjuvant therapeutics, there is a vast space for other putative therapeutic targets to be explored. The alpha subunit of the heterotrimeric G z protein (Gα z ) has been shown to promote beta-cell inflammation, dysfunction, death, and failure to replicate in the context of diabetes in a number of mouse models. Genetic loss of Gα z or inhibition of the Gα z signaling pathway through dietary interventions is protective against the development of insulitis and hyperglycemia. The multifaceted effects of Gα z in regards to beta-cell health in the context of diabetes make it an ideal therapeutic target for further study. It is our belief that a low-risk, effective therapy for type 1 diabetes mellitus will involve a multidimensional approach targeting a number of regulatory systems, not the least of which is the insulin-producing beta-cell. Impact statement The expanding

  8. Glucose-induced lipogenesis in pancreatic beta-cells is dependent on SREBP-1

    DEFF Research Database (Denmark)

    Sandberg, Maria B; Fridriksson, Jakob; Madsen, Lise

    2005-01-01

    High concentrations of glucose induce de novo fatty acid synthesis in pancreatic beta-cells and chronic exposure of elevated glucose and fatty acids synergize to induce accumulation of triglycerides, a phenomenon termed glucolipotoxicity. Here we investigate the role of sterol-regulatory element......, de novo fatty acid synthesis and lipid accumulation are induced primarily through sterol-regulatory elements (SREs) and not E-Boxes. Adenoviral expression of a dominant negative SREBP compromises glucose induction of some lipogenic genes and significantly reduces glucose-induction of de novo fatty...... acid synthesis. Thus, we demonstrate for the first time that SREBP activity is necessary for full glucose induction of de novo fatty acid synthesis in pancreatic beta-cells....

  9. The Importance of REST for Development and Function of Beta Cells

    DEFF Research Database (Denmark)

    Martin, David; Grapin-Botton, Anne

    2017-01-01

    that are crucial for both neuronal and pancreatic endocrine function, through the recruitment of multiple transcriptional and epigenetic co-regulators. REST targets include genes encoding transcription factors, proteins involved in exocytosis, synaptic transmission or ion channeling, and non-coding RNAs. REST......Beta cells are defined by the genes they express, many of which are specific to this cell type, and ensure a specific set of functions. Beta cells are also defined by a set of genes they should not express (in order to function properly), and these genes have been called forbidden genes. Among...... these, the transcriptional repressor RE-1 Silencing Transcription factor (REST) is expressed in most cells of the body, excluding most populations of neurons, as well as pancreatic beta and alpha cells. In the cell types where it is expressed, REST represses the expression of hundreds of genes...

  10. Dual role of proapoptotic BAD in insulin secretion and beta cell survival

    OpenAIRE

    Danial, Nika N.; Walensky, Loren D.; Zhang, Chen-Yu; Choi, Cheol Soo; Fisher, Jill K.; Molina, Anthony J. A.; Datta, Sandeep Robert; Pitter, Kenneth L.; Bird, Gregory H.; Wikstrom, Jakob D.; Deeney, Jude T.; Robertson, Kirsten; Morash, Joel; Kulkarni, Ameya; Neschen, Susanne

    2008-01-01

    The proapoptotic BCL-2 family member BAD resides in a glucokinase-containing complex that regulates glucose-driven mitochondrial respiration. Here, we present genetic evidence of a physiologic role for BAD in glucose-stimulated insulin secretion by beta cells. This novel function of BAD is specifically dependent upon the phosphorylation of its BH3 sequence, previously defined as an essential death domain. We highlight the pharmacologic relevance of phosphorylated BAD BH3 by using cell-permeab...

  11. Reference intervals for glucose, beta-cell polypeptides and counterregulatory factors during prolonged fasting

    DEFF Research Database (Denmark)

    Højlund, Kurt; Wildner-Christensen, M; Eshøj, O

    2001-01-01

    To establish reference intervals for the pancreatic beta-cell response and the counterregulatory hormone response to prolonged fasting, we studied 33 healthy subjects (16 males, 17 females) during a 72-h fast. Glucose, insulin, C-peptide, and proinsulin levels decreased (P ... of counterregulatory factors increased during the fast [P fasting (P ... decreased from the second to third day of fasting (P = 0.03). Males had higher glucose and glucagon levels and lower FFA levels during the fast (P

  12. Intracellular serotonin modulates insulin secretion from pancreatic beta-cells by protein serotonylation.

    Directory of Open Access Journals (Sweden)

    Nils Paulmann

    2009-10-01

    Full Text Available While serotonin (5-HT co-localization with insulin in granules of pancreatic beta-cells was demonstrated more than three decades ago, its physiological role in the etiology of diabetes is still unclear. We combined biochemical and electrophysiological analyses of mice selectively deficient in peripheral tryptophan hydroxylase (Tph1-/- and 5-HT to show that intracellular 5-HT regulates insulin secretion. We found that these mice are diabetic and have an impaired insulin secretion due to the lack of 5-HT in the pancreas. The pharmacological restoration of peripheral 5-HT levels rescued the impaired insulin secretion in vivo. These findings were further evidenced by patch clamp experiments with isolated Tph1-/- beta-cells, which clearly showed that the secretory defect is downstream of Ca(2+-signaling and can be rescued by direct intracellular application of 5-HT via the clamp pipette. In elucidating the underlying mechanism further, we demonstrate the covalent coupling of 5-HT by transglutaminases during insulin exocytosis to two key players in insulin secretion, the small GTPases Rab3a and Rab27a. This renders them constitutively active in a receptor-independent signaling mechanism we have recently termed serotonylation. Concordantly, an inhibition of such activating serotonylation in beta-cells abates insulin secretion. We also observed inactivation of serotonylated Rab3a by enhanced proteasomal degradation, which is in line with the inactivation of other serotonylated GTPases. Our results demonstrate that 5-HT regulates insulin secretion by serotonylation of GTPases within pancreatic beta-cells and suggest that intracellular 5-HT functions in various microenvironments via this mechanism in concert with the known receptor-mediated signaling.

  13. Glucocorticoids Inhibit Basal and Hormone-Induced Serotonin Synthesis in Pancreatic Beta Cells.

    Directory of Open Access Journals (Sweden)

    Moina Hasni Ebou

    Full Text Available Diabetes is a major complication of chronic Glucocorticoids (GCs treatment. GCs induce insulin resistance and also inhibit insulin secretion from pancreatic beta cells. Yet, a full understanding of this negative regulation remains to be deciphered. In the present study, we investigated whether GCs could inhibit serotonin synthesis in beta cell since this neurotransmitter has been shown to be involved in the regulation of insulin secretion. To this aim, serotonin synthesis was evaluated in vitro after treatment with GCs of either islets from CD1 mice or MIN6 cells, a beta-cell line. We also explored the effect of GCs on the stimulation of serotonin synthesis by several hormones such as prolactin and GLP 1. We finally studied this regulation in islet in two in vivo models: mice treated with GCs and with liraglutide, a GLP1 analog, and mice deleted for the glucocorticoid receptor in the pancreas. We showed in isolated islets and MIN6 cells that GCs decreased expression and activity of the two key enzymes of serotonin synthesis, Tryptophan Hydroxylase 1 (Tph1 and 2 (Tph2, leading to reduced serotonin contents. GCs also blocked the induction of serotonin synthesis by prolactin or by a previously unknown serotonin activator, the GLP-1 analog exendin-4. In vivo, activation of the Glucagon-like-Peptide-1 receptor with liraglutide during 4 weeks increased islet serotonin contents and GCs treatment prevented this increase. Finally, islets from mice deleted for the GR in the pancreas displayed an increased expression of Tph1 and Tph2 and a strong increased serotonin content per islet. In conclusion, our results demonstrate an original inhibition of serotonin synthesis by GCs, both in basal condition and after stimulation by prolactin or activators of the GLP-1 receptor. This regulation may contribute to the deleterious effects of GCs on beta cells.

  14. Calcium Co-regulates Oxidative Metabolism and ATP Synthase-dependent Respiration in Pancreatic Beta Cells

    Science.gov (United States)

    De Marchi, Umberto; Thevenet, Jonathan; Hermant, Aurelie; Dioum, Elhadji; Wiederkehr, Andreas

    2014-01-01

    Mitochondrial energy metabolism is essential for glucose-induced calcium signaling and, therefore, insulin granule exocytosis in pancreatic beta cells. Calcium signals are sensed by mitochondria acting in concert with mitochondrial substrates for the full activation of the organelle. Here we have studied glucose-induced calcium signaling and energy metabolism in INS-1E insulinoma cells and human islet beta cells. In insulin secreting cells a surprisingly large fraction of total respiration under resting conditions is ATP synthase-independent. We observe that ATP synthase-dependent respiration is markedly increased after glucose stimulation. Glucose also causes a very rapid elevation of oxidative metabolism as was followed by NAD(P)H autofluorescence. However, neither the rate of the glucose-induced increase nor the new steady-state NAD(P)H levels are significantly affected by calcium. Our findings challenge the current view, which has focused mainly on calcium-sensitive dehydrogenases as the target for the activation of mitochondrial energy metabolism. We propose a model of tight calcium-dependent regulation of oxidative metabolism and ATP synthase-dependent respiration in beta cell mitochondria. Coordinated activation of matrix dehydrogenases and respiratory chain activity by calcium allows the respiratory rate to change severalfold with only small or no alterations of the NAD(P)H/NAD(P)+ ratio. PMID:24554722

  15. Sirt1 regulates insulin secretion by repressing UCP2 in pancreatic beta cells.

    Directory of Open Access Journals (Sweden)

    Laura Bordone

    2006-02-01

    Full Text Available Sir2 and insulin/IGF-1 are the major pathways that impinge upon aging in lower organisms. In Caenorhabditis elegans a possible genetic link between Sir2 and the insulin/IGF-1 pathway has been reported. Here we investigate such a link in mammals. We show that Sirt1 positively regulates insulin secretion in pancreatic beta cells. Sirt1 represses the uncoupling protein (UCP gene UCP2 by binding directly to the UCP2 promoter. In beta cell lines in which Sirt1 is reduced by SiRNA, UCP2 levels are elevated and insulin secretion is blunted. The up-regulation of UCP2 is associated with a failure of cells to increase ATP levels after glucose stimulation. Knockdown of UCP2 restores the ability to secrete insulin in cells with reduced Sirt1, showing that UCP2 causes the defect in glucose-stimulated insulin secretion. Food deprivation induces UCP2 in mouse pancreas, which may occur via a reduction in NAD (a derivative of niacin levels in the pancreas and down-regulation of Sirt1. Sirt1 knockout mice display constitutively high UCP2 expression. Our findings show that Sirt1 regulates UCP2 in beta cells to affect insulin secretion.

  16. Early-Life Origins of Type 2 Diabetes: Fetal Programming of the Beta-Cell Mass

    Directory of Open Access Journals (Sweden)

    Bernard Portha

    2011-01-01

    Full Text Available A substantial body of evidence suggests that an abnormal intrauterine milieu elicited by maternal metabolic disturbances as diverse as undernutrition, placental insufficiency, diabetes or obesity, may program susceptibility in the fetus to later develop chronic degenerative diseases, such as obesity, hypertension, cardiovascular diseases and diabetes. This paper examines the developmental programming of glucose intolerance/diabetes by disturbed intrauterine metabolic condition experimentally obtained in various rodent models of maternal protein restriction, caloric restriction, overnutrition or diabetes, with a focus on the alteration of the developing beta-cell mass. In most of the cases, whatever the type of initial maternal metabolic stress, the beta-cell adaptive growth which normally occurs during gestation, does not take place in the pregnant offspring and this results in the development of gestational diabetes. Therefore gestational diabetes turns to be the ultimate insult targeting the offspring beta-cell mass and propagates diabetes risk to the next generation again. The aetiology and the transmission of spontaneous diabetes as encountered in the GK/Par rat model of type 2 diabetes, are discussed in such a perspective. This review also discusses the non-genomic mechanisms involved in the installation of the programmed effect as well as in its intergenerational transmission.

  17. Imatinib prevents beta cell death in vitro but does not improve islet transplantation outcome.

    Science.gov (United States)

    King, Aileen J F; Griffiths, Lisa A; Persaud, Shanta J; Jones, Peter M; Howell, Simon L; Welsh, Nils

    2016-05-01

    Introduction Improving islet transplantation outcome could not only bring benefits to individual patients but also widen the patient pool to which this life-changing treatment is available. Imatinib has previously been shown to protect beta cells from apoptosis in a variety of in vitro and in vivo models. The aim of this study was to investigate whether imatinib could be used to improve islet transplantation outcome. Methods Islets were isolated from C57Bl/6 mice and pre-cultured with imatinib prior to exposure to streptozotocin and cytokines in vitro. Cell viability and glucose-induced insulin secretion were measured. For transplantation experiments, islets were pre-cultured with imatinib for either 72 h or 24 h prior to transplantation into streptozotocin-diabetic C57Bl/6 mice. In one experimental series mice were also administered imatinib after islet transplantation. Results Imatinib partially protected islets from beta cell death in vitro. However, pre-culturing islets in imatinib or administering the drug to the mice in the days following islet transplantation did not improve blood glucose concentrations more than control-cultured islets. Conclusion Although imatinib protected against beta cell death from cytokines and streptozotocin in vitro, it did not significantly improve syngeneic islet transplantation outcome.

  18. Vanadyl Sulfate Treatment Stimulates Proliferation and Regeneration of Beta Cells in Pancreatic Islets

    Directory of Open Access Journals (Sweden)

    Samira Missaoui

    2014-01-01

    Full Text Available We examined the effects of vanadium sulfate (VOSO4 treatment at 5 and 10 mg/kg for 30 days on endocrine pancreas activity and histology in nondiabetic and STZ-induced diabetic rats. In diabetic group, blood glucose levels significantly increased while insulinemia level markedly decreased. At the end of treatment, VOSO4 at a dose of 10 mg/Kg normalized blood glucose level in diabetic group, restored insulinemia, and significantly improved insulin sensitivity. VOSO4 also increased in a dose-dependent manner the number of insulin immunopositive beta cells in pancreatic islets of nondiabetic rats. Furthermore, in the STZ-diabetic group, the decrease in the number of insulin immunopositive beta cells was corrected to reach the control level mainly with the higher dose of vanadium. Therefore, VOSO4 treatment normalized plasma glucose and insulin levels and improved insulin sensitivity in STZ-experimental diabetes and induced beta cells proliferation and/or regeneration in normal or diabetic rats.

  19. SIRT6-mediated transcriptional suppression of Txnip is critical for pancreatic beta cell function and survival in mice.

    Science.gov (United States)

    Qin, Kunhua; Zhang, Ning; Zhang, Zhao; Nipper, Michael; Zhu, Zhenxin; Leighton, Jake; Xu, Kexin; Musi, Nicolas; Wang, Pei

    2018-04-01

    Better understanding of how genetic and epigenetic components control beta cell differentiation and function is key to the discovery of novel therapeutic approaches to prevent beta cell dysfunction and failure in the progression of type 2 diabetes. Our goal was to elucidate the role of histone deacetylase sirtuin 6 (SIRT6) in beta cell development and homeostasis. Sirt6 endocrine progenitor cell conditional knockout and beta cell-specific knockout mice were generated using the Cre-loxP system. Mice were assayed for islet morphology, glucose tolerance, glucose-stimulated insulin secretion and susceptibility to streptozotocin. Transcriptional regulatory functions of SIRT6 in primary islets were evaluated by RNA-Seq analysis. Reverse transcription-quantitative (RT-q)PCR and immunoblot were used to verify and investigate the gene expression changes. Chromatin occupancies of SIRT6, H3K9Ac, H3K56Ac and active RNA polymerase II were evaluated by chromatin immunoprecipitation. Deletion of Sirt6 in pancreatic endocrine progenitor cells did not affect endocrine morphology, beta cell mass or insulin production but did result in glucose intolerance and defective glucose-stimulated insulin secretion in mice. Conditional deletion of Sirt6 in adult beta cells reproduced the insulin secretion defect. Loss of Sirt6 resulted in aberrant upregulation of thioredoxin-interacting protein (TXNIP) in beta cells. SIRT6 deficiency led to increased acetylation of histone H3 lysine residue at 9 (H3K9Ac), acetylation of histone H3 lysine residue at 56 (H3K56Ac) and active RNA polymerase II at the promoter region of Txnip. SIRT6-deficient beta cells exhibited a time-dependent increase in H3K9Ac, H3K56Ac and TXNIP levels. Finally, beta cell-specific SIRT6-deficient mice showed increased sensitivity to streptozotocin. Our results reveal that SIRT6 suppresses Txnip expression in beta cells via deacetylation of histone H3 and plays a critical role in maintaining beta cell function and viability

  20. Effects of vitamin A, C and E, or omega-3 fatty acid supplementation on the level of paraoxonase and arylesterase activity in streptozotocin-induced diabetic rats: an investigation of activities in plasma, and heart and liver homogenates.

    Science.gov (United States)

    Zarei, Mahnaz; Fakher, Shima; Tabei, Seyed Mohammad Bagher; Javanbakht, Mohammad Hassan; Derakhshanian, Hoda; Farahbakhsh-Farsi, Payam; Sadeghi, Mohammad Reza; Mostafavi, Ebrahim; Djalali, Mahmoud

    2016-03-01

    This study was designed and conducted to evaluate the effects of vitamin A, C and E supplementation, and omega-3 fatty acid supplementation on the activity of paraoxonase and arylesterase in an experimental model of diabetes mellitus. A total of 64 male Sprague Dawley® rats, each weighing 250 g, were randomly distributed into four groups: (a) normal control; (b) diabetic control; (c) diabetic with vitamin A, C and E supplementation; and (d) diabetic with omega-3 fatty acid supplementation. The animals were anaesthetised after four weeks of intervention, and paraoxonase and arylesterase activity in blood plasma, and liver and heart homogenates were measured. Arylesterase activity in the heart and liver homogenates was significantly lower in the diabetic control group than in the normal control group (p Vitamin A, C and E supplementation, and omega-3 fatty acid supplementation significantly increased liver arylesterase activity (p Vitamin A, C and E, or omega-3 fatty acid supplementation were found to increase liver arylesterase activity in streptozotocin-induced diabetic rats. These supplements may be potential agents for the treatment of diabetes mellitus complications. Copyright: © Singapore Medical Association.

  1. Effects of Hydro-alcoholic Extract from Arctium lappa L. (Burdock) Root on Gonadotropins, Testosterone, and Sperm Count and Viability in Male Mice with Nicotinamide/ Streptozotocin-Induced Type 2 Diabetes.

    Science.gov (United States)

    Ahangarpour, Akram; Oroojan, Ali Akbar; Heidari, Hamid; Ghaedi, Ehsan; Taherkhani, Reza

    2015-01-01

    Reproductive dysfunction is a complication of diabetes. Arctium lappa (burdock) root has hypoglycemic and antioxidative properties, which are traditionally used for treatment of impotence and sterility. Therefore, the aim of this study is to investigate the effects of its hydro alcoholic extract on gonadotropin, testosterone, and sperm parameters in nicotinamide/ streptozotocin-induced diabetic mice. In this experimental study, 56 adult male Naval Medical Research Institute (NMRI) mice (30-35 g) were randomly divided into seven groups: control, diabetes, diabetes + glibenclamide (0.25 mg/kg), diabetes + extract (200 or 300 mg/kg), and extract (200 or 300 mg/kg). Diabetes was induced with intraperitoneal injection of nicotinamide (NA) and streptozotocin (STZ). Twenty-four hours after the last extract and drug administration, serum samples, testes, and cauda epididymis were removed immediately for experimental assessment. Body weight, serum luteinizing hormone (LH), follicle stimulating hormone (FSH), and testosterone levels, and sperm count (P lappa plant has an effect on the health of the reproductive system in order to improve diabetic conditions.

  2. Antidiabetic Potentiality of the Aqueous-Methanolic Extract of Seed of Swietenia mahagoni (L.) Jacq. in Streptozotocin-Induced Diabetic Male Albino Rat: A Correlative and Evidence-Based Approach with Antioxidative and Antihyperlipidemic Activities.

    Science.gov (United States)

    De, Debasis; Chatterjee, Kausik; Ali, Kazi Monjur; Bera, Tushar Kanti; Ghosh, Debidas

    2011-01-01

    Antidiabetic, antioxidative, and antihyperlipidemic activities of aqueous-methanolic (2 : 3) extract of Swietenia mahagoni (L.) Jacq. (family Meliaceae) seed studied in streptozotocin-induced diabetic rats. Feeding with seed extract (25 mg 0.25 mL distilled water(-1)100 gm b.w.(-1)rat(-1) day(-1)) for 21 days to diabetic rat lowered the blood glucose level as well as the glycogen level in liver. Moreover, activities of antioxidant enzymes like catalase, peroxidase, and levels of the products of free radicals like conjugated diene and thiobarbituric acid reactive substances in liver, kidney, and skeletal muscles were corrected towards the control after this extract treatment in this model. Furthermore, the seed extract corrected the levels of serum urea, uric acid, creatinine, cholesterol, triglyceride, and lipoproteins towards the control level in this experimental diabetic model. The results indicated the potentiality of the extract of S. mahagoni seed for the correction of diabetes and its related complications like oxidative stress and hyperlipidemia. The extract may be a good candidate for developing a safety, tolerable, and promising neutraceutical treatment for the management of diabetes.

  3. Antidiabetic Potentiality of the Aqueous-Methanolic Extract of Seed of Swietenia mahagoni (L. Jacq. in Streptozotocin-Induced Diabetic Male Albino Rat: A Correlative and Evidence-Based Approach with Antioxidative and Antihyperlipidemic Activities

    Directory of Open Access Journals (Sweden)

    Debasis De

    2011-01-01

    Full Text Available Antidiabetic, antioxidative, and antihyperlipidemic activities of aqueous-methanolic (2 : 3 extract of Swietenia mahagoni (L. Jacq. (family Meliaceae seed studied in streptozotocin-induced diabetic rats. Feeding with seed extract (25 mg 0.25 mL distilled water−1100 gm b.w.−1rat−1 day−1 for 21 days to diabetic rat lowered the blood glucose level as well as the glycogen level in liver. Moreover, activities of antioxidant enzymes like catalase, peroxidase, and levels of the products of free radicals like conjugated diene and thiobarbituric acid reactive substances in liver, kidney, and skeletal muscles were corrected towards the control after this extract treatment in this model. Furthermore, the seed extract corrected the levels of serum urea, uric acid, creatinine, cholesterol, triglyceride, and lipoproteins towards the control level in this experimental diabetic model. The results indicated the potentiality of the extract of S. mahagoni seed for the correction of diabetes and its related complications like oxidative stress and hyperlipidemia. The extract may be a good candidate for developing a safety, tolerable, and promising neutraceutical treatment for the management of diabetes.

  4. Effects of hydroalcoholic extract of Rhus coriaria seed on glucose and insulin related biomarkers, lipid profile, and hepatic enzymes in nicotinamide-streptozotocin-induced type II diabetic male mice.

    Science.gov (United States)

    Ahangarpour, Akram; Heidari, Hamid; Junghani, Majid Salehizade; Absari, Reza; Khoogar, Mehdi; Ghaedi, Ehsan

    2017-10-01

    Type 2 diabetes often leads to dislipidemia and abnormal activity of hepatic enzymes. The purpose of this study was to evaluate the antidiabetic and hypolipidemic properties of Rhus coriaria ( R. coriaria ) seed extrac on nicotinamide-streptozotocin induced type 2 diabetic mice. In this experimental study, 56 male Naval Medical Research Institute mice (30-35 g) were randomly separated into seven groups: control, diabetic group, diabetic mice treated with glibenclamide (0.25 mg/kg, as standard antidiabetic drug) or R. coriaria seed extract in doses of 200 and 300 mg/kg, and control groups received these two doses of extract orally for 28 days. Induction of diabetes was done by intraperitoneal injection of nicotinamide and streptozotocin. Ultimately, body weight of mice, blood levels of glucose, insulin, hepatic enzymes, leptin, and lipid profile were assayed. After induction of type 2 diabetes, level of glucose, cholesterol, low density lipoprotein, serum glutamic oxaloacetic transaminase, and serum glutamic pyruvic transaminase increased and level of insulin and high density lipoprotein decreased remarkably. Administration of both doses of extract decreased level of glucose and cholesterol significantly in diabetic mice. LDL level decreased in treated group with dose of 300 mg/kg of the extract. Although usage of the extract improved level of other lipid profiles, insulin and hepatic enzymes, changes weren't significant. This study showed R. coriaria seeds administration has a favorable effect in controlling some blood parameters in type 2 diabetes. Therefore it may be beneficial in the treatment of diabetes.

  5. CISH has no non-redundant functions in glucose homeostasis or beta cell proliferation during pregnancy in mice.

    Science.gov (United States)

    Jiao, Yang; Rieck, Sebastian; Le Lay, John; Kaestner, Klaus H

    2013-11-01

    Increased beta cell proliferation during pregnancy is mediated by the Janus kinase 2/signal transducer and activator of transcription 5 (JAK2/STAT5) signalling pathway in response to increased lactogen levels. Activation of the pathway leads to transcriptional upregulation of Cish (encoding cytokine-inducible SH2 domain-containing protein), a member of the suppressor of cytokine signalling (SOCS) family of genes, forming a negative-feedback loop. Here, we examined whether conditional gene ablation of Cish in the pancreas improves beta cell proliferation and beta cell function during pregnancy in mice. We derived mice with a novel, conditional loxP allele for Cish. Pancreas-specific ablation of Cish was achieved by crossing Cish (loxP/loxP) mice with Pdx1-Cre (Early) mice. Beta cell proliferation was quantified by BrdU labelling. Glucose homeostasis was examined with glucose tolerance tests and determination of plasma insulin levels. The expression of other Socs genes and target genes of p-STAT5 related to beta cell function and beta cell proliferation was determined by quantitative PCR. There was no difference in beta cell proliferation or glucose homeostasis between the Cish mutant group and the control group. The p-STAT5 protein level was the same in Cish mutant and control mice. Socs2 gene expression was higher in Cish mutant than control mice at pregnancy day 9.5. The expression of other Socs genes was the same between control and mutant mice. Our results show that CISH has no non-redundant functions in beta cell proliferation or glucose homeostasis during pregnancy in mice. Socs2 might compensate for the loss of Cish during pregnancy.

  6. Islet autoantibodies and residual beta cell function in type 1 diabetes children followed for 3-6 years

    DEFF Research Database (Denmark)

    Sørensen, Jesper Sand; Vaziri-Sani, Fariba; Maziarz, M

    2012-01-01

    To test if islet autoantibodies at diagnosis of type 1 diabetes (T1DM) and after 3-6 years with T1D predict residual beta-cell function (RBF) after 3-6 years with T1D.......To test if islet autoantibodies at diagnosis of type 1 diabetes (T1DM) and after 3-6 years with T1D predict residual beta-cell function (RBF) after 3-6 years with T1D....

  7. Increased androgen levels in rats impair glucose-stimulated insulin secretion through disruption of pancreatic beta cell mitochondrial function.

    Science.gov (United States)

    Wang, Hongdong; Wang, Xiaping; Zhu, Yunxia; Chen, Fang; Sun, Yujie; Han, Xiao

    2015-11-01

    Although insulin resistance is recognized to contribute to the reproductive and metabolic phenotypes of polycystic ovary syndrome (PCOS), pancreatic beta cell dysfunction plays an essential role in the progression from PCOS to the development of type 2 diabetes. However, the role of insulin secretory abnormalities in PCOS has received little attention. In addition, the precise changes in beta cells and the underlying mechanisms remain unclear. In this study, we therefore attempted to elucidate potential mechanisms involved in beta cell alterations in a rat model of PCOS. Glucose-induced insulin secretion was measured in islets isolated from DHT-treated and control rats. Oxygen consumption rate (OCR), ATP production, and mitochondrial copy number were assayed to evaluate mitochondrial function. Glucose-stimulated insulin secretion is significantly decreased in islets from DHT-treated rats. On the other hand, significant reductions are observed in the expression levels of several key genes involved in mitochondrial biogenesis and in mitochondrial OCR and ATP production in DHT-treated rat islets. Meanwhile, we found that androgens can directly impair beta cell function by inducing mitochondrial dysfunction in vitro in an androgen receptor dependent manner. For the first time, our study demonstrates that increased androgens in female rats can impair glucose-stimulated insulin secretion partly through disruption of pancreatic beta cell mitochondrial function. This work has significance for hyperandrogenic women with PCOS: excess activation of the androgen receptor by androgens may provoke beta cell dysfunction via mitochondrial dysfunction. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. ß-cell specific overexpression of suppressor of cytokine signalling-3 does not protect against multiple low dose streptozotocin induced type 1 diabetes in mice

    DEFF Research Database (Denmark)

    Börjesson, A; Rønn, S G; Karlsen, A E

    2011-01-01

    We investigated the impact of ß-cell specific overexpression of suppressor of cytokine signalling-3 (SOCS-3) on the development of multiple low dose streptozotocin (MLDSTZ) induced Type 1 diabetes and the possible mechanisms involved. MLDSTZ treatment was administered to RIP-SOCS-3 transgenic......RNA in islet cells and secretion of IL-1Ra into culture medium. MLDSTZ treatment caused gradual hyperglycemia both in the wt mice and in the transgenic mice with the latter tending to be more sensitive. In vitro experiments on wt and transgenic islets did not reveal any differences in sensitivity to damaging...

  9. Chaperones ameliorate beta cell dysfunction associated with human islet amyloid polypeptide overexpression.

    Directory of Open Access Journals (Sweden)

    Lisa Cadavez

    Full Text Available In type 2 diabetes, beta-cell dysfunction is thought to be due to several causes, one being the formation of toxic protein aggregates called islet amyloid, formed by accumulations of misfolded human islet amyloid polypeptide (hIAPP. The process of hIAPP misfolding and aggregation is one of the factors that may activate the unfolded protein response (UPR, perturbing endoplasmic reticulum (ER homeostasis. Molecular chaperones have been described to be important in regulating ER response to ER stress. In the present work, we evaluate the role of chaperones in a stressed cellular model of hIAPP overexpression. A rat pancreatic beta-cell line expressing hIAPP exposed to thapsigargin or treated with high glucose and palmitic acid, both of which are known ER stress inducers, showed an increase in ER stress genes when compared to INS1E cells expressing rat IAPP or INS1E control cells. Treatment with molecular chaperone glucose-regulated protein 78 kDa (GRP78, also known as BiP or protein disulfite isomerase (PDI, and chemical chaperones taurine-conjugated ursodeoxycholic acid (TUDCA or 4-phenylbutyrate (PBA, alleviated ER stress and increased insulin secretion in hIAPP-expressing cells. Our results suggest that the overexpression of hIAPP induces a stronger response of ER stress markers. Moreover, endogenous and chemical chaperones are able to ameliorate induced ER stress and increase insulin secretion, suggesting that improving chaperone capacity can play an important role in improving beta-cell function in type 2 diabetes.

  10. Lactate overrides central nervous but not beta-cell glucose sensing in humans.

    Science.gov (United States)

    Schmid, Sebastian M; Jauch-Chara, Kamila; Hallschmid, Manfred; Oltmanns, Kerstin M; Peters, Achim; Born, Jan; Schultes, Bernd

    2008-12-01

    Lactate has been shown to serve as an alternative energy substrate in the central nervous system and to interact with hypothalamic glucose sensors. On the background of marked similarities between central nervous and beta-cell glucose sensing, we examined whether lactate also interacts with pancreatic glucose-sensing mechanisms in vivo. The effects of intravenously infused lactate vs placebo (saline) on central nervous and pancreatic glucose sensing were assessed during euglycemic and hypoglycemic clamp experiments in 10 healthy men. The release of neuroendocrine counterregulatory hormones during hypoglycemia was considered to reflect central nervous glucose sensing, whereas endogenous insulin secretion as assessed by serum C-peptide levels served as an indicator of pancreatic beta-cell glucose sensing. Lactate infusion blunted the counterregulatory hormonal responses to hypoglycemia, in particular, the release of epinephrine (P = .007) and growth hormone (P = .004), so that higher glucose infusion rates (P = .012) were required to maintain the target blood glucose levels. In contrast, the decrease in C-peptide concentrations during the hypoglycemic clamp remained completely unaffected by lactate (P = .60). During euglycemic clamp conditions, lactate infusion did not affect the concentrations of C-peptide and of counterregulatory hormones, with the exception of norepinephrine levels that were lower during lactate than saline infusion (P = .049) independently of the glycemic condition. Data indicate that glucose sensing of beta-cells is specific to glucose, whereas glucose sensing at the central nervous level can be overridden by lactate, reflecting the brain's ability to rely on lactate as an alternative major energy source.

  11. Expression of transient receptor potential ankyrin 1 (TRPA1 and its role in insulin release from rat pancreatic beta cells.

    Directory of Open Access Journals (Sweden)

    De-Shou Cao

    Full Text Available Several transient receptor potential (TRP channels are expressed in pancreatic beta cells and have been proposed to be involved in insulin secretion. However, the endogenous ligands for these channels are far from clear. Here, we demonstrate the expression of the transient receptor potential ankyrin 1 (TRPA1 ion channel in the pancreatic beta cells and its role in insulin release. TRPA1 is an attractive candidate for inducing insulin release because it is calcium permeable and is activated by molecules that are produced during oxidative glycolysis.Immunohistochemistry, RT-PCR, and Western blot techniques were used to determine the expression of TRPA1 channel. Ca²⁺ fluorescence imaging and electrophysiology (voltage- and current-clamp techniques were used to study the channel properties. TRPA1-mediated insulin release was determined using ELISA.TRPA1 is abundantly expressed in a rat pancreatic beta cell line and freshly isolated rat pancreatic beta cells, but not in pancreatic alpha cells. Activation of TRPA1 by allyl isothiocyanate (AITC, hydrogen peroxide (H₂O₂, 4-hydroxynonenal (4-HNE, and cyclopentenone prostaglandins (PGJ₂ and a novel agonist methylglyoxal (MG induces membrane current, depolarization, and Ca²⁺ influx leading to generation of action potentials in a pancreatic beta cell line and primary cultured pancreatic beta cells. Activation of TRPA1 by agonists stimulates insulin release in pancreatic beta cells that can be inhibited by TRPA1 antagonists such as HC030031 or AP-18 and by RNA interference. TRPA1-mediated insulin release is also observed in conditions of voltage-gated Na⁺ and Ca²⁺ channel blockade as well as ATP sensitive potassium (K(ATP channel activation.We propose that endogenous and exogenous ligands of TRPA1 cause Ca²⁺ influx and induce basal insulin release and that TRPA1-mediated depolarization acts synergistically with K(ATP channel blockade to facilitate insulin release.

  12. Multilayer network representation of membrane potential and cytosolic calcium concentration dynamics in beta cells

    International Nuclear Information System (INIS)

    Gosak, Marko; Dolenšek, Jurij; Markovič, Rene; Slak Rupnik, Marjan; Marhl, Marko; Stožer, Andraž

    2015-01-01

    Highlights: • Physiological processes within and among pancreatic beta cells are very complex. • We analyze the simultaneous recordings of membrane potential and calcium dynamics. • We represent the interaction patterns among beta cells as a multilayer network. • The nature of the intracellular dynamics is found to rely on the network structure. - Abstract: Modern theory of networks has been recognized as a very successful methodological concept for the description and analysis of complex systems. However, some complex systems are more complex than others. For instance, several real-life systems are constituted by interdependent subsystems and their elements are subjected to different types of interactions that can also change with time. Recently, the multilayer network formalism has been proposed as a general theoretical framework for the description and analysis of such multi-dimensional complex systems and is acquiring more and more prominence in terms of a new research direction. In the present study, we use this methodology for the description of functional connectivity patterns and signal propagation between pancreatic beta cells in an islet of Langerhans at the levels of membrane potential (MP) and cytosolic calcium concentration ([Ca"2"+]_c) dynamics to study the extent of overlap in the two networks and to clarify whether time lags between the two signals in individual cells are in any way dependent on the role these cells play in the functional networks. The two corresponding network layers are constructed on the basis of signal directions and pairwise correlations, whereas the interlayer connections represent the time lag between both measured signals. Our results confirm our previous finding that both MP and [Ca"2"+]_c change spread across an islet in the form of a depolarization and a [Ca"2"+]_c wave, respectively. Both types of waves follow nearly the same path and the networks in both layers have a similar but not entirely the same structure

  13. Antioxidant and regulatory role of mitochondrial uncoupling protein UCP2 in pancreatic beta-cells

    Czech Academy of Sciences Publication Activity Database

    Ježek, Petr; Olejár, Tomáš; Smolková, Katarína; Ježek, Jan; Dlasková, Andrea; Plecitá-Hlavatá, Lydie; Zelenka, Jaroslav; Špaček, Tomáš; Engstová, Hana; Reguera Pajuelo, David; Jabůrek, Martin

    2014-01-01

    Roč. 63, Suppl.1 (2014), S73-S91 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GAP302/10/0346; GA ČR(CZ) GAP305/12/1247; GA ČR(CZ) GPP304/10/P204; GA MŠk(CZ) EE2.3.30.0025 Institutional support: RVO:67985823 Keywords : mitochondria * uncoupling protein UCP2 * pancreatic beta-cells * reactive oxygen species * glucose-stimulated insulin secretion Subject RIV: EA - Cell Biology Impact factor: 1.293, year: 2014

  14. Use of digitonin permeabilization for characterization of calcium incorporated into. beta. cells in response to glucose

    Energy Technology Data Exchange (ETDEWEB)

    Wesslen, N [Uppsala Univ. (Sweden)

    1985-01-01

    ..beta.. cell-rich pancreatic islets were used to characterize /sup 45/Ca uptake into pools with different sensitivities to permeabilization with digitonin. The plasma and secretory granule membranes were among the membranes most sensitive to digitonin treatment whereas the mitochondria were more resistant. Most of the /sup 45/Ca incorporated in response to glucose was found in a fraction released after exposure to a high concentration of digitonin. The results suggest that glucose promotes active sequestration of calcium in mitochondria and that the uptake of /sup 45/Ca in the secretory granules in secondary to a raised cytosolic Ca/sup 2 +/ activity.

  15. Renoprotective Effect of Danhong Injection on Streptozotocin-Induced Diabetic Rats through a Peroxisome Proliferator-Activated Receptor γ Mediated Pathway

    Directory of Open Access Journals (Sweden)

    Xue Yang

    2018-01-01

    Full Text Available The aim of the study was to investigate the protective effect of Danhong injection (DHI on diabetic kidney disease and explore the potential mechanisms. Diabetic kidney disease was induced by unilateral nephrectomy, high-fat diet, and streptozotocin. After DHI administration, the renal function deterioration, 24-hour total urine protein excretion, and elevated serum lipid levels were reversed to some extent, and the renal pathological damage was also ameliorated. The KEGG pathway enrichment analysis demonstrated that the PPARγ signal pathway was significantly upregulated in DH group. And the increased expressions of PPARγ and UCP-1 were confirmed by immunohistochemistry, whereas the p38MAPK was significantly decreased. These data show that DHI could delay the progress of DKD, and the effect might be achieved in part by activating the PPARγ signaling pathway.

  16. Antihyperglycaemic and organic protective effects on pancreas, liver and kidney by polysaccharides from Hericium erinaceus SG-02 in streptozotocin-induced diabetic mice.

    Science.gov (United States)

    Zhang, Chen; Li, Juan; Hu, Chunlong; Wang, Jing; Zhang, Jianjun; Ren, Zhenzhen; Song, Xinling; Jia, Le

    2017-09-07

    The present work was designed to investigate the antihyperglycaemic and protective effects of two Hericium erinaceus intracellular polysaccharide (HIPS) purified fractions (HIPS1 and HIPS2) from mycelia of H. erinaceus SG-02 on pancreas, liver and kidney in streptozotocin (STZ)-induced diabetic mice. The supplementation of HIPS1 and HIPS2 significantly decreased the blood glucose (GLU) levels; suppressed the abnormal elevations of alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea nitrogen (BUN) and creatinine (CRE) levels in serum; improved the antioxidant enzymatic (superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT)) activities; and attenuated the pathological damage to these organs. The HIPS1 showed superior effects in antihyperglycaemia and organic protection than HIPS2 possible owing to the abundant functional groups (-NH 2 , -COOH and S=O) in HIPS1, indicating that H. erinaceus SG-02 could be used as a functional food and natural drug for the prevention of diabetes and its complications.

  17. Beneficial effect of 17β-estradiol on hyperglycemia and islet β-cell functions in a streptozotocin-induced diabetic rat model

    International Nuclear Information System (INIS)

    Yamabe, Noriko; Kang, Ki Sung; Zhu Baoting

    2010-01-01

    The modulating effect of estrogen on glucose homeostasis remains a controversial issue at present. In this study, we sought to determine the beneficial effect of 17β-estradiol (E 2 ) on hyperglycemia and islet β-cell functions in streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats were injected i.p. with STZ to induce a relatively mild diabetic condition. The rats were then treated with E 2 orally at 500 μg/kg body weight/day for 15 days to evaluate the modulating effect on hyperglycemia, insulin secretion, and islet β-cell proliferation. E 2 administration for 10 days significantly lowered plasma glucose levels, increased plasma insulin levels, and improved glucose tolerance by attenuating insulin response to oral glucose loading. These beneficial effects of E 2 were accompanied by increases in islet number and volume, rate of islet cell proliferation, and the amount of insulin secreted. The growth-stimulatory effect of E 2 on islet cells was linked to the functions of the estrogen receptor α. Notably, these protective effects of E 2 on diabetic conditions were basically not observed when the STZ-treated rats had a more severe degree of islet damage and hyperglycemia. Taken together, we conclude that E 2 can promote the regeneration of damaged pancreatic islets by stimulating β-cell proliferation in diabetic rats, and this effect is accompanied by improvements in glucose tolerance and a decrease in plasma glucose levels. These findings suggest that oral administration of E 2 may be beneficial in diabetic patients with an accelerated loss of islet β-cells.

  18. In Vitro Antioxidant Effects of Aloe barbadensis Miller Extracts and the Potential Role of These Extracts as Antidiabetic and Antilipidemic Agents on Streptozotocin-Induced Type 2 Diabetic Model Rats

    Directory of Open Access Journals (Sweden)

    Md. Ibrahim Khalil

    2012-11-01

    Full Text Available In this study, the total phenolic and flavonoid contents, the 2,2-diphenyl-1-picryl hydrazyl (DPPH radical scavenging ability and the ferric reducing power (FRAP of Aloe vera were measured to determine the antioxidant activity of this species. The in vivo antidiabetic effects of the plant were also investigated using streptozotocin-induced type 2 diabetic model rats that were divided into five groups based on the treatment received: (1 water (WC; (2 glibenclamide; (3 concentrated gel extract (Gel-C; (4 ethanol (80% gel extract (Gel-Et; and (5 ethanol (80% skin extract of Aloe vera (Skin-Et. Skin-Et, which contained the highest level of total phenolics (62.37 ± 1.34 mggallic acid/kg and flavonoids (20.83 ± 0.77 mg/kg, exhibited the highest scavenging activity (85.01 ± 0.52% and the greatest reducing power (185.98 ± 0.41 µM, indicating that the skin contained the highest level of antioxidants. The oral consumption of Gel-Et for 4 weeks a caused significant reduction in the fasting serum glucose levels of the rats. The rats in the Gel-C-, Gel-Et- and Skin-Et-treated groups experienced a reduction in their total cholesterol levels by 11%, 17% and 25%, respectively and a reduction in their LDL cholesterol levels by 45%, 3% and 69%, respectively. The in vivo experimental antioxidant parameter MDA is strongly correlated with the in vitro antioxidant parameters of flavonoids and polyphenols, namely the DPPH and FRAP values (r = 0.94, 0.92, 0.93, 0.90, thus confirming the antioxidant potential of the Aloe vera extracts.

  19. The time has come to test the beta cell preserving effects of exercise in patients with new onset type 1 diabetes

    DEFF Research Database (Denmark)

    Narendran, Parth; Solomon, Thomas; Kennedy, Amy

    2015-01-01

    Type 1 diabetes is characterised by immune-mediated destruction of insulin-producing beta cells. Significant beta cell function is usually present at the time of diagnosis with type 1 diabetes, and preservation of this function has important clinical benefits. The last 30 years have seen a number...... for physical exercise as a therapy for the preservation of beta cell function in patients with newly diagnosed type 1 diabetes. We highlight possible mechanisms by which exercise could preserve beta cell function and then present evidence from other models of diabetes that demonstrate that exercise preserves...... beta cell function. We conclude by proposing that there is now a need for studies to explore whether exercise can preserve beta cell in patients newly diagnosed with type 1 diabetes....

  20. Effect of Mucuna pruriens (Linn.) on oxidative stress-induced structural alteration of corpus cavernosum in streptozotocin-induced diabetic rat.

    Science.gov (United States)

    Suresh, Sekar; Prakash, Seppan

    2011-07-01

    Erectile dysfunction is one of the major secondary complications of diabetes. Mucuna pruriens (M. pruriens), a leguminous plant identified for its antidiabetic, aphrodisiac, and fertility enhancing properties, has been the choice of Indian traditional medicine. The objective of the present study was to analyze the efficacy of M. pruriens on free radicals-mediated penile tissue alterations in hyperglycemic male rats. Methods.  Male albino rats were divided as group I (sham) control, group II (STZ) diabetes-induced (streptozotocin 60 mg/kg of body weight [bw] in 0.1 M citrate buffer), group III (STZ + MP) diabetic rats administered with 200 mg/kg bw of ethanolic extract of M. pruriens seed, group IV (STZ + SIL) diabetic rats administered with 5 mg/kg bw of sildenafil citrate, group V (sham + MP) administered with 200 mg/kg bw of extract alone, and group VI (sham + SIL) administered with 5 mg/kg bw of sildenafil citrate. The M. pruriens and sildenafil citrate were given (gavage) once daily for a period of 60 days. At the end of 60 days, the animals were sacrificed and subjected to analysis of reactive oxygen species levels, enzymic and nonenzymic antioxidant levels, levels of NOx, histological, and histomorphometrical study of penile tissue. Remedial use of M. pruriens seed extract on diabetes-induced erectile tissue damage. Significantly high levels of oxidative stress and low levels of antioxidants in the penile tissue seem to contribute to the increased collagen deposition and fibrosis of erectile tissue in STZ rats. Relatively, there was increased damage in STZ + SIL group. Supplementation of M. pruriens in STZ + MP group has revealed the potency to overcome oxidative stress, and good preservation of penile histoarchitecture.  The ethanolic extract of M. pruriens seed significantly recovered or protected erectile tissue from the oxidative stress-induced degeneration by its antioxidant potentials. These findings propound to serve mankind by the treatment of

  1. Involvement of interleukin 1 and interleukin 1 antagonist in pancreatic beta-cell destruction in insulin-dependent diabetes mellitus

    DEFF Research Database (Denmark)

    Mandrup-Poulsen, T; Zumsteg, U; Reimers, J

    1993-01-01

    In this review we propose that the balance between the action of interleukin 1 (IL-1) and its natural antagonist IL-1ra on the level of the insulin-producing pancreatic beta-cell may play a decisive role in the pathogenesis of insulin-dependent diabetes mellitus (IDDM). We argue that IL-1...... potentiated by other cytokines (tumor necrosis factor alpha, interferon gamma) is an important effector molecule involved in both early and late events in the immune-mediated process that leads to beta-cell destruction and IDDM. We also point out that surprisingly high molar excesses of IL-1ra over IL-1...... are necessary to block the action of IL-1 on islet beta-cells compared to islet alpha-cells in vitro and in animals. We suggest that the selectivity of beta-cell destruction in IDDM may be conferred on several levels: (1) homing of beta-cell antigen specific T cells, (2) targeted delivery of cytokines...

  2. T Cell-Mediated Beta Cell Destruction: Autoimmunity and Alloimmunity in the Context of Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Adam L. Burrack

    2017-12-01

    Full Text Available Type 1 diabetes (T1D results from destruction of pancreatic beta cells by T cells of the immune system. Despite improvements in insulin analogs and continuous blood glucose level monitoring, there is no cure for T1D, and some individuals develop life-threatening complications. Pancreas and islet transplantation have been attractive therapeutic approaches; however, transplants containing insulin-producing cells are vulnerable to both recurrent autoimmunity and conventional allograft rejection. Current immune suppression treatments subdue the immune system, but not without complications. Ideally a successful approach would target only the destructive immune cells and leave the remaining immune system intact to fight foreign pathogens. This review discusses the autoimmune diabetes disease process, diabetic complications that warrant a transplant, and alloimmunity. First, we describe the current understanding of autoimmune destruction of beta cells including the roles of CD4 and CD8 T cells and several possibilities for antigen-specific tolerance induction. Second, we outline diabetic complications necessitating beta cell replacement. Third, we discuss transplant recognition, potential sources for beta cell replacement, and tolerance-promoting therapies under development. We hypothesize that a better understanding of autoreactive T cell targets during disease pathogenesis and alloimmunity following transplant destruction could enhance attempts to re-establish tolerance to beta cells.

  3. Analysis of the effect of diabetes type 2 duration on beta cell secretory function and insulin resistance

    Directory of Open Access Journals (Sweden)

    Popović Ljiljana

    2006-01-01

    Full Text Available Diabetes type 2 is a chronic metabolic disorder. Pathogenesis of diabetes type 2 results from the impaired insulin secretion, impaired insulin action and increased endogenous glucose production. Diabetes evolves through several phases characterized by qualitative and quantitative changes of beta cell secretory function. The aim of our study was to analyze the impact of diabetes duration on beta cell secretory function and insulin resistance. The results indicated significant negative correlation of diabetes duration and fasting insulinemia, as well as beta cell secretory function assessed by HOMA β index. Our study also found significant negative correlation of diabetes duration and insulin resistance assessed by HOMA IR index. Significant positive correlation was established between beta cell secretory capacity (fasting insulinemia and HOMA β and insulin resistance assessed by HOMA IR index, independently of diabetes duration. These results indicate that: beta cell secretory capacity, assessed by HOMA β index, significantly decreases with diabetes duration. In parallel with decrease of fasting insulinemia, reduction of insulin resistance assessed by HOMA IR index was found as well.

  4. Nuclear orphan receptor TLX affects gene expression, proliferation and cell apoptosis in beta cells

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xiaoli; Xiong, Xiaokan; Dai, Zhe; Deng, Haohua; Sun, Li; Hu, Xuemei; Zhou, Feng; Xu, Yancheng, E-mail: oxyccc@163.com

    2015-12-04

    Nuclear orphan receptor TLX is an essential regulator of the growth of neural stem cells. However, its exact function in pancreatic islet cells is still unknown. In the present study, gene expression profiling analysis revealed that overexpression of TLX in beta cell line MIN6 causes suppression of 176 genes and upregulation of 49 genes, including a cadre of cell cycle, cell proliferation and cell death control genes, such as Btg2, Ddit3 and Gadd45a. We next examined the effects of TLX overexpression on proliferation, apoptosis and insulin secretion in MIN6 cells. Proliferation analysis using EdU assay showed that overexpression of TLX increased percentage of EdU-positive cells. Cell cycle and apoptosis analysis revealed that overexpression of TLX in MIN6 cells resulted in higher percentage of cells exiting G1 into S-phase, and a 58.8% decrease of cell apoptosis induced by 0.5 mM palmitate. Moreover, TLX overexpression did not cause impairment of insulin secretion. Together, we conclude that TLX is among factors capable of controlling beta cell proliferation and survival, which may serve as a target for the development of novel therapies for diabetes. - Highlights: • TLX overexpression in MIN6 cell causes significant expression changes of 225 genes. • TLX overexpression promotes MIN6 cell proliferation and decreases cell apoptosis. • TLX overexpression does not cause impairment of insulin secretion.

  5. Nuclear orphan receptor TLX affects gene expression, proliferation and cell apoptosis in beta cells

    International Nuclear Information System (INIS)

    Shi, Xiaoli; Xiong, Xiaokan; Dai, Zhe; Deng, Haohua; Sun, Li; Hu, Xuemei; Zhou, Feng; Xu, Yancheng

    2015-01-01

    Nuclear orphan receptor TLX is an essential regulator of the growth of neural stem cells. However, its exact function in pancreatic islet cells is still unknown. In the present study, gene expression profiling analysis revealed that overexpression of TLX in beta cell line MIN6 causes suppression of 176 genes and upregulation of 49 genes, including a cadre of cell cycle, cell proliferation and cell death control genes, such as Btg2, Ddit3 and Gadd45a. We next examined the effects of TLX overexpression on proliferation, apoptosis and insulin secretion in MIN6 cells. Proliferation analysis using EdU assay showed that overexpression of TLX increased percentage of EdU-positive cells. Cell cycle and apoptosis analysis revealed that overexpression of TLX in MIN6 cells resulted in higher percentage of cells exiting G1 into S-phase, and a 58.8% decrease of cell apoptosis induced by 0.5 mM palmitate. Moreover, TLX overexpression did not cause impairment of insulin secretion. Together, we conclude that TLX is among factors capable of controlling beta cell proliferation and survival, which may serve as a target for the development of novel therapies for diabetes. - Highlights: • TLX overexpression in MIN6 cell causes significant expression changes of 225 genes. • TLX overexpression promotes MIN6 cell proliferation and decreases cell apoptosis. • TLX overexpression does not cause impairment of insulin secretion.

  6. Nuclear orphan receptor TLX affects gene expression, proliferation and cell apoptosis in beta cells.

    Science.gov (United States)

    Shi, Xiaoli; Xiong, Xiaokan; Dai, Zhe; Deng, Haohua; Sun, Li; Hu, Xuemei; Zhou, Feng; Xu, Yancheng

    Nuclear orphan receptor TLX is an essential regulator of the growth of neural stem cells. However, its exact function in pancreatic islet cells is still unknown. In the present study, gene expression profiling analysis revealed that overexpression of TLX in beta cell line MIN6 causes suppression of 176 genes and upregulation of 49 genes, including a cadre of cell cycle, cell proliferation and cell death control genes, such as Btg2, Ddit3 and Gadd45a. We next examined the effects of TLX overexpression on proliferation, apoptosis and insulin secretion in MIN6 cells. Proliferation analysis using EdU assay showed that overexpression of TLX increased percentage of EdU-positive cells. Cell cycle and apoptosis analysis revealed that overexpression of TLX in MIN6 cells resulted in higher percentage of cells exiting G1 into S-phase, and a 58.8% decrease of cell apoptosis induced by 0.5 mM palmitate. Moreover, TLX overexpression did not cause impairment of insulin secretion. Together, we conclude that TLX is among factors capable of controlling beta cell proliferation and survival, which may serve as a target for the development of novel therapies for diabetes. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. LGR5 and Nanog identify stem cell signature of pancreas beta cells which initiate pancreatic cancer.

    Science.gov (United States)

    Amsterdam, Abraham; Raanan, Calanit; Schreiber, Letizia; Polin, Nava; Givol, David

    2013-04-05

    Pancreas cancer, is the fourth leading cause of cancer death but its cell of origin is controversial. We compared the localization of stem cells in normal and cancerous pancreas using antibodies to the stem cell markers Nanog and LGR5. Here we show, for the first time, that LGR5 is expressed in normal pancreas, exclusively in the islets of Langerhans and it is co-localized, surprisingly, with Nanog and insulin in clusters of beta cells. In cancerous pancreas Nanog and LGR5 are expressed in the remaining islets and in all ductal cancer cells. We observed insulin staining among the ductal cancer cells, but not in metastases. This indicates that the islet's beta cells, expressing LGR5 and Nanog markers are the initiating cells of pancreas cancer, which migrated from the islets to form the ductal cancerous tissue, probably after mutation and de-differentiation. This discovery may facilitate treatment of this devastating cancer. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Planar Cell Polarity Controls Pancreatic Beta Cell Differentiation and Glucose Homeostasis

    Directory of Open Access Journals (Sweden)

    Cedric Cortijo

    2012-12-01

    Full Text Available Planar cell polarity (PCP refers to the collective orientation of cells within the epithelial plane. We show that progenitor cells forming the ducts of the embryonic pancreas express PCP proteins and exhibit an active PCP pathway. Planar polarity proteins are acquired at embryonic day 11.5 synchronously to apicobasal polarization of pancreas progenitors. Loss of function of the two PCP core components Celsr2 and Celsr3 shows that they control the differentiation of endocrine cells from polarized progenitors, with a prevalent effect on insulin-producing beta cells. This results in a decreased glucose clearance. Loss of Celsr2 and 3 leads to a reduction of Jun phosphorylation in progenitors, which, in turn, reduces beta cell differentiation from endocrine progenitors. These results highlight the importance of the PCP pathway in cell differentiation in vertebrates. In addition, they reveal that tridimensional organization and collective communication of cells are needed in the pancreatic epithelium in order to generate appropriate numbers of endocrine cells.

  9. Effect on pancreatic beta cells and nerve cells by low let x-ray

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kwang Hun [Dept. of Nuclear Medicine, Kyungbuk National University Hospital, Daegu (Korea, Republic of); Kim, Kgu Hwan [Dept. of Radiological Technology, Daegu health College, Daegu (Korea, Republic of)

    2014-03-15

    Cultured pancreatic beta cells and nerve cells, it is given normal condition of 10% FBS (fetal bovine serum), 11.1 mM glucose and hyperglycemia condition of 1% FBS, 30 mM glucose. For low LET X-ray irradiated with 0.5 Gy/hr dose-rate(total dose: 0.5 to 5 Gy). Survival rates were measured by MTT assay. When non irradiated, differentiated in the pancreatic beta cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a small reduction. However increasing the total dose of X-ray, the survival rate of normal conditions decreased slightly compared to the survival rate of hyperglycemia conditions, the synergistic effect was drastically reduced. When non irradiated, undifferentiated in the nerve cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a large reduction. As the cumulative dose of X-ray normal conditions and hyperglycemia were all relatively rapid cell death. But the rate of decreased survivals by almost parallel to the reduction proceed and it didn't show synergistic effect.

  10. IKKβ inhibition prevents fat-induced beta cell dysfunction in vitro and in vivo in rodents.

    Science.gov (United States)

    Ivovic, Aleksandar; Oprescu, Andrei I; Koulajian, Khajag; Mori, Yusaku; Eversley, Judith A; Zhang, Liling; Nino-Fong, Rodolfo; Lewis, Gary F; Donath, Marc Y; Karin, Michael; Wheeler, Michael B; Ehses, Jan; Volchuk, Allen; Chan, Catherine B; Giacca, Adria

    2017-10-01

    We have previously shown that oxidative stress plays a causal role in beta cell dysfunction induced by fat. Here, we address whether the proinflammatory kinase inhibitor of (nuclear factor) κB kinase β (IKKβ), which is activated by oxidative stress, is also implicated. Fat (oleate or olive oil) was infused intravenously in Wistar rats for 48 h with or without the IKKβ inhibitor salicylate. Thereafter, beta cell function was evaluated in vivo using hyperglycaemic clamps or ex vivo in islets isolated from fat-treated rats. We also exposed rat islets to oleate in culture, with or without salicylate and 4(2'-aminoethyl)amino-1,8-dimethylimidazo(1,2-a)quinoxaline; BMS-345541 (BMS, another inhibitor of IKKβ) and evaluated beta cell function in vitro. Furthermore, oleate was infused in mice treated with BMS and in beta cell-specific Ikkb-null mice. 48 h infusion of fat impaired beta-cell function in vivo, assessed using the disposition index (DI), in rats (saline: 1.41 ± 0.13; oleate: 0.95 ± 0.11; olive oil [OLO]: 0.87 ± 0.15; p < 0.01 for both fats vs saline) and in mice (saline: 2.51 ± 0.39; oleate: 1.20 ± 0.19; p < 0.01 vs saline) and ex vivo (i.e., insulin secretion, units are pmol insulin islet -1  h -1 ) in rat islets (saline: 1.51 ± 0.13; oleate: 1.03 ± 0.10; OLO: 0.91 ± 0.13; p < 0.001 for both fats vs saline) and the dysfunction was prevented by co-infusion of salicylate in rats (oleate + salicylate: 1.30 ± 0.09; OLO + salicylate: 1.33 ± 0.23) or BMS in mice (oleate + BMS: 2.25 ± 0.42) in vivo and by salicylate in rat islets ex vivo (oleate + salicylate: 1.74 ± 0.31; OLO + salicylate: 1.54 ± 0.29). In cultured islets, 48 h exposure to oleate impaired beta-cell function ([in pmol insulin islet -1  h -1 ] control: 0.66 ± 0.12; oleate: 0.23 ± 0.03; p < 0.01 vs saline), an effect prevented by both inhibitors (oleate + salicylate: 0.98 ± 0.08; oleate + BMS: 0.50 ± 0.02). Genetic

  11. The Role of Helicobacter pylori Seropositivity in Insulin Sensitivity, Beta Cell Function, and Abnormal Glucose Tolerance

    Directory of Open Access Journals (Sweden)

    Lou Rose Malamug

    2014-01-01

    Full Text Available Infection, for example, Helicobacter pylori (H. pylori, has been thought to play a role in the pathogenesis of type 2 diabetes mellitus (T2DM. Our aim was to determine the role of H. pylori infection in glucose metabolism in an American cohort. We examined data from 4,136 non-Hispanic white (NHW, non-Hispanic black (NHB, and Mexican Americans (MA aged 18 and over from the NHANES 1999-2000 cohort. We calculated the odds ratios for states of glucose tolerance based on the H. pylori status. We calculated and compared homeostatic model assessment insulin resistance (HOMA-IR and beta cell function (HOMA-B in subjects without diabetes based on the H. pylori status. The results were adjusted for age, body mass index (BMI, poverty index, education, alcohol consumption, tobacco use, and physical activity. The H. pylori status was not a risk factor for abnormal glucose tolerance. After adjustment for age and BMI and also adjustment for all covariates, no difference was found in either HOMA-IR or HOMA-B in all ethnic and gender groups except for a marginally significant difference in HOMA-IR in NHB females. H. pylori infection was not a risk factor for abnormal glucose tolerance, nor plays a major role in insulin resistance or beta cell dysfunction.

  12. Garlic and Resveratrol attenuate diabetic complications, loss of β-cells, pancreatic and hepatic oxidative stress in streptozotocin-induced diabetic rats

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    Gagandeep Kaur

    2016-10-01

    Full Text Available Abstract:The study was aimed at finding the effect of garlic and resveratrol on loss of β-cells and diabetic complication in streptozotocin (STZ-induced Type-I diabetic rats. Rats were injected with single dose STZ (50mg/kg, i.p. for induction of type 1 diabetes (Dia and compared with control group. Rats from third (Dia+Gar, fourth (Dia+Resv and fifth (Dia+Met groups were fed raw garlic homogenate (250 mg/kg/day, resveratrol (25 mg/kg/day and metformin (500 mg/kg/day orally, respectively for a period of 4 weeks. Diabetic group had decreased serum insulin and hydrogen sulfide levels along with increased blood glucose and glycated hemoglobin, triglyceride, uric acid and nitric oxide levels. Significant (p<0.05 increase in pancreatic and hepatic TBARS, conjugated dienes, nitric oxide, and AGE level and significant (p<0.05 decrease in SOD, catalase, H2S, GSH level were observed in diabetic group. Administration of garlic, resveratrol and metformin significantly (p<0.05 normalized most of the altered metabolic and oxidative stress parameters as well as histopathological changes. Administration of garlic, resveratrol and 9metformin in diabetic rat decreases pancreatic β-cell damage and hepatic injury. Our data concluded that administration of garlic showed more promising effect in terms of reducing oxidative stress and pathological changes when compared to resveratrol and metformin groups.

  13. Influence of fluoride on streptozotocin induced diabetic nephrotoxicity in mice: Protective role of Asian ginseng (Panax ginseng & banaba (Lagerstroemia speciosa on mitochondrial oxidative stress

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    Mahaboob P Basha

    2013-01-01

    Full Text Available Background & objectives: Chronic fluoride intoxication through drinking water is a serious health problem. Patients with diabetes are known to have impaired renal function and elimination of fluoride from the body is mainly done through kidney. Fluoride toxicity in diabetes patients may aggravate complications. In this study, the influence of fluoride was assessed on streptozotocin (STZ induced diabetes in mice as also the efficacy/protective effective of oral supplementation of ginseng (GE and banaba leaf extracts (BLE. Methods: The efficacy of plant extracts, GE and BLE at doses of 50, 150, 250 mg/kg b.w./day alone and in combination, was tested for a period of 15 days on fluoride treated STZ induced diabetic animals. Results: Fluoride exposure to mice with STZ-induced diabetes produced significant changes in OSI (organo-somatic index, fluoride content, blood glucose, urea, serum creatinine and oxidative stress indices in kidney tissues with evident histological alterations. Among the antioxidant treatments, combination therapy of GE and BLE at 150 mg/kg b.w. significantly normalized the impaired biochemical variables in kidney tissues of fluoride toxicated diabetic mice. Interpretations & conclusions: High fluoride uptake was found to be diabetogenic and further aggravated the renal oxidative damage and thereby the toxicity in mice with STZ induced diabetes mice. GE and BLE exposure individually or in combination at a dose of 150 mg/kg b.w./day for 15 days exhibited protective effects on fluoride toxicated STZ induced nephrotoxicity in mice.

  14. In vitro alpha-amylase inhibition and in vivo antioxidant potential of Momordica dioica seeds in streptozotocin-induced oxidative stress in diabetic rats

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    P. Sailaja Rao

    2017-09-01

    Full Text Available Momordica dioica Roxb. Commonly known as “Kakora” in Telugu, is used in the Indian traditional system of medicine for the treatment of diabetes. The aim of this study was to investigate the antidiabetic activity of methanolic extract of M. dioica seeds (MEMD in streptozotocin (STZ induced diabetic rats. The in vitro α-amylase inhibitory activity of the MEMD was done by spectrophotometric method. Diabetes was induced by STZ (45 mg/kg; i.p, MEMD (100 & 200 mg/kg; b.wt and standard drug metformin (50 mg/kg; b.wt were administered to the diabetic rats. Blood glucose was estimated on the 11th day and the level of MDA, SOD and CAT was estimated in the liver tissue homogenate after the 15 days of experimental period. MEMD showed significant inhibition of alpha amylase activity and the IC50 was found to be 48 μg/ml. Oral administration of MEMD significantly reduced blood glucose level (P < 0.05, diminished the MDA level and refurbished depleted antioxidant enzymes and Insulin level to normalcy. These findings revealed that M. dioica seeds possess antihyperglycemic, antioxidant and anti lipid peroxidative activity and thus mitigate STZ-induced oxidative damage.

  15. Metabolomic Analysis of Biochemical Changes in the Plasma of High-Fat Diet and Streptozotocin-Induced Diabetic Rats after Treatment with Isoflavones Extract of Radix Puerariae

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    Yan Zhang

    2016-01-01

    Full Text Available The main purpose of this study was to investigate the protective effects of total isoflavones from Radix Puerariae (PTIF in diabetic rats. Diabetes was induced by a high-fat diet and intraperitoneal injection of low-dose streptozotocin (STZ; 40 mg/kg. At 26 weeks onwards, PTIF 421 mg/kg was administrated to the rats once daily consecutively for 10 weeks. Metabolic profiling changes were analyzed by Ultraperformance Liquid Chromatography-Quadrupole-Exactive Orbitrap-Mass Spectrometry (UPLC-Q-Exactive Orbitrap-MS. The principal component discriminant analysis (PCA-DA, partial least-squares discriminant analysis (PLS-DA, and orthogonal partial least-squares discriminant analysis (OPLS-DA were used for multivariate analysis. Moreover, free amino acids in serum were determined by high-performance liquid chromatography with fluorescence detector (HPLC-FLD. Additionally, oxidative stress and inflammatory cytokines were evaluated. Eleven potential metabolite biomarkers, which are mainly related to the coagulation, lipid metabolism, and amino acid metabolism, have been identified. PCA-DA scores plots indicated that biochemical changes in diabetic rats were gradually restored to normal after administration of PTIF. Furthermore, the levels of BCAAs, glutamate, arginine, and tyrosine were significantly increased in diabetic rats. Treatment with PTIF could regulate the disturbed amino acid metabolism. Consequently, PTIF has great therapeutic potential in the treatment of DM by improving metabolism disorders and inhibiting oxidative damage.

  16. The Antidiabetic Activity of Curry Leaves “Murraya Koenigii” on the Glucose Levels, Kidneys, and Islets of Langerhans of Rats with Streptozotocin Induced Diabetes

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    Imad M Al-Ani

    2017-08-01

    Full Text Available Background: The aims of this study were to explore the antihyperglycemic effect of curry leaves, Murraya koenigii "MK" aqueous extract, and to examine its possible protective effects on the islets of Langerhans and kidneys of streptozotocin (STZ diabetic rats. Methods: Thirty healthy adult male Sprague Dawley rats were randomized into five groups (n=6; normal control, normal treated with "MK" control, diabetic control (non-treated with "MK", diabetic treated with 200 mg/kg MK aqueous leaf extract and diabetic treated with 400 mg/kg MK aqueous leaf extract. Blood glucose levels and body weight were monitored gravimetrically. The animals were sacrificed on the 30th day; the kidney and pancreatic tissues were processed for histological studies. Results: The diabetic group showed considerable loss of body weight and increase in blood glucose levels and degeneration of the glomeruli and renal convoluted tubules and atrophied islets with disintegration of β-cells. Treatment of diabetic rats with MK extract showed significant (p < 0.001 improvement in blood glucose levels and body weight gain. The MK extract also caused an improvement in tissue injury induced by STZ injection in the kidney and islets of Langerhans. Conclusions: These findings highlighted the beneficial effects of MK aqueous extract against cellular oxidative damage in STZ-induced diabetic rats.

  17. Effects of exendin-4 on glucose tolerance, insulin secretion, and beta-cell proliferation depend on treatment dose, treatment duration and meal contents

    International Nuclear Information System (INIS)

    Arakawa, Masayuki; Ebato, Chie; Mita, Tomoya; Hirose, Takahisa; Kawamori, Ryuzo; Fujitani, Yoshio; Watada, Hirotaka

    2009-01-01

    Beta-cell proliferation is regulated by various metabolic demands including peripheral insulin resistance, obesity, and hyperglycemia. In addition to enhancement of glucose-induced insulin secretion, agonists for glucagon-like peptide-1 receptor (GLP-1R) stimulate proliferation and inhibit apoptosis of beta-cells, thereby probably preserve beta-cell mass. To evaluate the beta-cell preserving actions of GLP-1R agonists, we assessed the acute and chronic effects of exendin-4 on beta-cell proliferation, mass and glucose tolerance in C57BL/6J mice under various conditions. Short-term administration of high-dose exendin-4 transiently stimulated beta-cell proliferation. Comparative transcriptomic analysis showed upregulation of IGF-1 receptor and its downstream effectors in islets. Treatment of mice with exendin-4 daily for 4 weeks (long-term administration) and feeding high-fat diet resulted in significant inhibition of weight gain and improvement of glucose tolerance with reduced insulin secretion and beta-cell mass. These findings suggest that long-term GLP-1 treatment results in insulin sensitization of peripheral organs, rather than enhancement of beta-cell proliferation and function, particularly when animals are fed high-fat diet. Thus, the effects of exendin-4 on glucose tolerance, insulin secretion, and beta-cell proliferation largely depend on treatment dose, duration of treatment and meal contents. While GLP-1 enhances proliferation of beta-cells in some diabetic mice models, our results suggest that GLP-1 stimulates beta-cell growth only when expansion of beta-cell mass is required to meet metabolic demands.

  18. Effects of exendin-4 on glucose tolerance, insulin secretion, and beta-cell proliferation depend on treatment dose, treatment duration and meal contents

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, Masayuki; Ebato, Chie; Mita, Tomoya [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Hirose, Takahisa [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University School of Medicine, Tokyo (Japan); Kawamori, Ryuzo [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University School of Medicine, Tokyo (Japan); Center for Beta Cell Biology and Regeneration, Juntendo University School of Medicine, Tokyo (Japan); Sportology Center, Juntendo University School of Medicine, Tokyo (Japan); Fujitani, Yoshio, E-mail: fujitani@juntendo.ac.jp [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University School of Medicine, Tokyo (Japan); Watada, Hirotaka, E-mail: hwatada@juntendo.ac.jp [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Sportology Center, Juntendo University School of Medicine, Tokyo (Japan)

    2009-12-18

    Beta-cell proliferation is regulated by various metabolic demands including peripheral insulin resistance, obesity, and hyperglycemia. In addition to enhancement of glucose-induced insulin secretion, agonists for glucagon-like peptide-1 receptor (GLP-1R) stimulate proliferation and inhibit apoptosis of beta-cells, thereby probably preserve beta-cell mass. To evaluate the beta-cell preserving actions of GLP-1R agonists, we assessed the acute and chronic effects of exendin-4 on beta-cell proliferation, mass and glucose tolerance in C57BL/6J mice under various conditions. Short-term administration of high-dose exendin-4 transiently stimulated beta-cell proliferation. Comparative transcriptomic analysis showed upregulation of IGF-1 receptor and its downstream effectors in islets. Treatment of mice with exendin-4 daily for 4 weeks (long-term administration) and feeding high-fat diet resulted in significant inhibition of weight gain and improvement of glucose tolerance with reduced insulin secretion and beta-cell mass. These findings suggest that long-term GLP-1 treatment results in insulin sensitization of peripheral organs, rather than enhancement of beta-cell proliferation and function, particularly when animals are fed high-fat diet. Thus, the effects of exendin-4 on glucose tolerance, insulin secretion, and beta-cell proliferation largely depend on treatment dose, duration of treatment and meal contents. While GLP-1 enhances proliferation of beta-cells in some diabetic mice models, our results suggest that GLP-1 stimulates beta-cell growth only when expansion of beta-cell mass is required to meet metabolic demands.

  19. Deep sea minerals prolong life span of streptozotocin-induced diabetic rats by compensatory augmentation of the IGF-I-survival signaling and inhibition of apoptosis.

    Science.gov (United States)

    Liao, Hung-En; Shibu, Marthandam Asokan; Kuo, Wei-Wen; Pai, Pei-Ying; Ho, Tsung-Jung; Kuo, Chia-Hua; Lin, Jing-Ying; Wen, Su-Ying; Viswanadha, Vijaya Padma; Huang, Chih-Yang

    2016-07-01

    Consumption of deep sea minerals (DSM), such as magnesium, calcium, and potassium, is known to reduce hypercholesterolemia-induced myocardial hypertrophy and cardiac-apoptosis and provide protection against cardiovascular diseases. Heart diseases develop as a lethal complication among diabetic patients usually due to hyperglycemia-induced cardiac-apoptosis that causes severe cardiac-damages, heart failure, and reduced life expectancy. In this study, we investigated the potential of DSM and its related cardio-protection to increase the life expectancy in diabetic rats. In this study, a heart failure rat model was developed by using streptozotocin (65 mg kg(-1) ) IP injection. Different doses of DSM-1× (37 mg kg(-1) day(-1) ), 2× (74 mg kg(-1) day(-1) ) and 3× (111 mg kg(-1) day(-1) ), were administered to the rats through gavages for 4 weeks. The positive effects of DSM on the survival rate of diabetes rats were determined with respect to the corresponding effects of MgSO4 . Further, to understand the mechanism by which DSM enhances the survival of diabetic rats, their potential to regulate cardiac-apoptosis and control cardiac-dysfunction were examined. Echocardiogram, tissue staining, TUNEL assay, and Western blotting assay were used to investigate modulations in the myocardial contractile function and related signaling protein expression. The results showed that DSM regulate apoptosis and complement the cardiomyocyte proliferation by enhancing survival mechanisms. Moreover DSM significantly reduced the mortality rate and enhanced the survival rate of diabetic rats. Experimental results show that DSM administration can be an effective strategy to improve the life expectancy of diabetic subjects by improving cardiac-cell proliferation and by controlling cardiac-apoptosis and associated cardiac-dysfunction. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 769-781, 2016. © 2015 Wiley Periodicals, Inc.

  20. The zinc transporter ZNT3 co-localizes with insulin in INS-1E pancreatic beta cells and influences cell survival, insulin secretion capacity, and ZNT8 expression

    DEFF Research Database (Denmark)

    Smidt, Kamille; Larsen, Agnete; Brønden, Andreas

    2016-01-01

    Zinc trafficking in pancreatic beta cells is tightly regulated by zinc transporting (ZNTs) proteins. The role of different ZNTs in the beta cells is currently being clarified. ZNT8 transports zinc into insulin granules and is critical for a correct insulin crystallization and storage in the granu......Zinc trafficking in pancreatic beta cells is tightly regulated by zinc transporting (ZNTs) proteins. The role of different ZNTs in the beta cells is currently being clarified. ZNT8 transports zinc into insulin granules and is critical for a correct insulin crystallization and storage...

  1. The ectopic expression of Pax4 in the mouse pancreas converts progenitor cells into alpha and subsequently beta cells

    DEFF Research Database (Denmark)

    Collombat, Patrick; Xu, Xiaobo; Ravassard, Philippe

    2009-01-01

    We have previously reported that the loss of Arx and/or Pax4 gene activity leads to a shift in the fate of the different endocrine cell subtypes in the mouse pancreas, without affecting the total endocrine cell numbers. Here, we conditionally and ectopically express Pax4 using different cell......-specific promoters and demonstrate that Pax4 forces endocrine precursor cells, as well as mature alpha cells, to adopt a beta cell destiny. This results in a glucagon deficiency that provokes a compensatory and continuous glucagon+ cell neogenesis requiring the re-expression of the proendocrine gene Ngn3. However......, the newly formed alpha cells fail to correct the hypoglucagonemia since they subsequently acquire a beta cell phenotype upon Pax4 ectopic expression. Notably, this cycle of neogenesis and redifferentiation caused by ectopic expression of Pax4 in alpha cells is capable of restoring a functional beta cell...

  2. Phosphorylation events implicating p38 and PI3K mediate tungstate-effects in MIN6 beta cells

    International Nuclear Information System (INIS)

    Piquer, Sandra; Barcelo-Batllori, Silvia; Julia, Marta; Marzo, Nuria; Nadal, Belen; Guinovart, Joan J.; Gomis, Ramon

    2007-01-01

    Oral administration of sodium tungstate is an effective treatment for diabetes in animal models. Several lines of evidence indicate the pancreatic beta cell as one of the targets of tungstate action. Here, we examined the molecular mechanism by which this compound exerts its effects on the beta cell line MIN6. Tungstate treatment induced phosphorylation and subsequent activation of p38 and PI3K which in turn are implicated in tungstate PDX-1 nuclear localization and activation. Although no effect was observed in glucose-induced insulin secretion we found that tungstate activates basal insulin release, a process driven, at least in part, by activation of p38. These results show a direct involvement of p38 and PI3K phosphorylation in the mechanism of action of tungstate in the beta cell

  3. Properties of Flavonoids Isolated from the Bark of Eysenhardtia polystachya and Their Effect on Oxidative Stress in Streptozotocin-Induced Diabetes Mellitus in Mice

    Science.gov (United States)

    Garcia-Campoy, Abraham Heriberto; Muñiz-Ramirez, Alethia

    2016-01-01

    Six new flavonoids 2′,4′-dihydroxychalcone-6′-O-β-d-glucopyranoside (1), α,3,2′,4′-tetrahydroxy-4-methoxy-dihydrochalcone-3′-C-β-glucopyranosy-6′-O-β-d-glucopyranoside (2), 7-hydroxy-5,8′-dimethoxy-6′α-l-rhamnopyranosyl-8-(3-phenyl-trans-acryloyl)-1-benzopyran-2-one (3), 6′7-dihydroxy-5,8-dimethoxy-8(3-phenyl-trans-acryloyl)-1-benzopyran-2-one (4), 9-hydroxy-3,8-dimethoxy-4-prenylpterocarpan (5), and α,4,4′-trihydroxydihydrochalcone-2′-O-β-d-glucopyranoside (6) were isolated from bark of Eysenhardtia polystachya. Antidiabetic activity of compounds 1–5 in terms of their cellular antioxidant and free radical scavenging and also in streptozotocin- (STZ-) induced diabetic mice was evaluated on liver transaminases, lipid peroxidation, total bilirubin, total protein, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (CSH-Px), and glutathione reductase (GSH). Results indicated that 1–5 scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl (∙OH), nitric oxide radicals (NO∙), superoxide anion radical (O2 ∙−), radical cation (ABTS∙+), and hydrogen peroxide (H2O2) radical, and protection against H2O2 induced BSA damage was also observed. Furthermore, 1–5 showed ability to decrease the oxidative stress in H9c2 cell. Diabetic mice present high levels of lipid peroxide, total protein, SGPT, SGOT, ALP, and TB. However, treatment of STZ-induced diabetes in mice with 1–5 reduced levels of these enzymes leading to protector effect of liver. In addition, with treatment with 1–5, increases in radical scavenging enzymes of CSH-Px, SOD, GSH, and CAT have also been observed in diabetic mice. The antioxidant properties of compounds 1–5 are a promising strategy for ameliorating therapeutic effects by avoiding disorders in the normal redox reactions in healthy cells which consequently could alleviate complications of diabetes. PMID:27668038

  4. Antidiabetic effects of Morus alba fruit polysaccharides on high-fat diet- and streptozotocin-induced type 2 diabetes in rats.

    Science.gov (United States)

    Jiao, Yukun; Wang, Xueqian; Jiang, Xiang; Kong, Fansheng; Wang, Shumei; Yan, Chunyan

    2017-03-06

    group. Moreover, MFP50 and MFP90 induced repair of damaged pancreatic tissues of the diabetic rats. The hypoglycemic effect of MFP50 was more stable than MFP90, whereas the hypolipidemic effect of MFP90 was slightly better than MFP50. Moreover, the expression levels of InsR, IRS-2, Akt and GLUT4 in the MFP90 group significantly increased relative to that of the T2DM group. MFP50 and MFP90 have markedly antihyperglycemic and antihyperlipidemic effects and can clearly relieve diabetes symptoms in the T2DM rat model. The M. alba fruit polysaccharides may potentially be utilized as an effective treatment for T2DM. Further research into the structures of active M. alba fruit polysaccharides and their mechanisms in promoting antidiabetic effects are underway. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  5. The long-acting GLP-1 derivative NN2211 ameliorates glycemia and increases beta-cell mass in diabetic mice

    DEFF Research Database (Denmark)

    Rolin, Bidda; Larsen, Marianne O; Gotfredsen, Carsten F

    2002-01-01

    in food intake, there were no significant differences between NN2211 and vehicle treatment, and body weight was not affected. Histological examination revealed that beta-cell proliferation and mass were not increased significantly in ob/ob mice with NN2211, although there was a strong tendency...... for increased proliferation. In db/db mice, exendin-4 and NN2211 decreased blood glucose compared with vehicle, but NN2211 had a longer duration of action. Food intake was lowered only on day 1 with both compounds, and body weight was unaffected. beta-Cell proliferation rate and mass were significantly...

  6. Activation of transmembrane bile acid receptor TGR5 stimulates insulin secretion in pancreatic {beta} cells

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Divya P.; Rajagopal, Senthilkumar; Mahavadi, Sunila [Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA (United States); Mirshahi, Faridoddin [Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA (United States); Grider, John R. [Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA (United States); Murthy, Karnam S., E-mail: skarnam@vcu.edu [Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA (United States); Sanyal, Arun J., E-mail: asanyal@mcvh-vcu.edu [Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA (United States)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer G protein coupled receptor TGR5 is expressed in mouse and human islets. Black-Right-Pointing-Pointer TGR5 is coupled to activation of Gs and Ca{sup 2+} release via cAMP/Epac/PLC-{epsilon} pathway. Black-Right-Pointing-Pointer Activation of TGR5 by bile salts and selective ligands causes insulin secretion. Black-Right-Pointing-Pointer TGR5 could be a potential therapeutic target to treat diabetes. -- Abstract: Bile acids act as signaling molecules and stimulate the G protein coupled receptor, TGR5, in addition to nuclear farnesoid X receptor to regulate lipid, glucose and energy metabolism. Bile acid induced activation of TGR5 in the enteroendocrine cells promotes glucagon like peptide-1 (GLP-1) release, which has insulinotropic effect in the pancreatic {beta} cells. In the present study, we have identified the expression of TGR5 in pancreatic {beta} cell line MIN6 and also in mouse and human pancreatic islets. TGR5 selective ligands, oleanolic acid (OA) and INT-777 selectively activated G{alpha}{sub s} and caused an increase in intracellular cAMP and Ca{sup 2+}. OA and INT-777 also increased phosphoinositide (PI) hydrolysis and the increase was blocked by NF449 (a selective G{alpha}{sub s} inhibitor) or (U73122) (PI hydrolysis inhibitor). OA, INT-777 and lithocholic acid increased insulin release in MIN6 and human islets and the increase was inhibited by treatment with NF449, (U73122) or BAPTA-AM (chelator of calcium), but not with myristoylated PKI (PKA inhibitor), suggesting that the release is dependent on G{sub s}/cAMP/Ca{sup 2+} pathway. 8-pCPT-2 Prime -O-Me-cAMP, a cAMP analog, which activates Epac, but not PKA also stimulated PI hydrolysis. In conclusion, our study demonstrates that the TGR5 expressed in the pancreatic {beta} cells regulates insulin secretion and highlights the importance of ongoing therapeutic strategies targeting TGR5 in the control of glucose homeostasis.

  7. Study of beta-cell function (by HOMA model) in metabolic syndrome.

    Science.gov (United States)

    Garg, M K; Dutta, M K; Mahalle, Namita

    2011-07-01

    The clustering of cardiovascular risk factors is termed the metabolic syndrome (MS), which strongly predict risk of diabetes and cardiovascular disease. Many studies implicate insulin resistance (IR) in the development of diabetes, but ignore the contribution of beta-cell dysfunction. Hence, we studied beta-cell function, as assessed by HOMA model, in subjects with MS. We studied 50 subjects with MS diagnosed by IDF criteria and 24 healthy age- and sex-matched controls. Clinical evaluation included anthropometry, body fat analysis by bioimpedance, biochemical, and insulin measurement. IR and secretion were calculated by HOMA model. Subjects with MS had more IR (HOMA-IR) than controls (3.35 ± 3.14 vs. 1.76 ± 0.53, P = 0.029) and secreted less insulin (HOMA-S) than controls (66.80 ± 69.66 vs. 144.27 ± 101.61, P = 0.0003), although plasma insulin levels were comparable in both groups (10.7 ± 10.2 vs. 8.2 ± 2.38, P = 0.44). HOMA-IR and HOMA-S were related with number of metabolic abnormalities. HOMA-IR was positively associated with body mass index, waist hip ratio, body fat mass, and percent body fat. HOMA-S was negatively associated with waist hip ratio, fasting plasma glucose and total cholesterol and positively with basal metabolic rate. Percent body fat was an independent predictor of HOMA-IR and waist hip ratio of HOMA-S in multiple regression analysis. Subjects with MS have increased IR and decreased insulin secretion compared with healthy controls. Lifestyle measures have been shown to improve IR, insulin secretion, and various components and effects of MS. Hence, there is an urgent need for public health measures to prevent ongoing epidemic of diabetes and cardiovascular disease.

  8. The putative imidazoline receptor agonist, harmane, promotes intracellular calcium mobilisation in pancreatic beta-cells.

    Science.gov (United States)

    Squires, Paul E; Hills, Claire E; Rogers, Gareth J; Garland, Patrick; Farley, Sophia R; Morgan, Noel G

    2004-10-06

    beta-Carbolines (including harmane and pinoline) stimulate insulin secretion by a mechanism that may involve interaction with imidazoline I(3)-receptors but which also appears to be mediated by actions that are additional to imidazoline receptor agonism. Using the MIN6 beta-cell line, we now show that both the imidazoline I(3)-receptor agonist, efaroxan, and the beta-carboline, harmane, directly elevate cytosolic Ca(2+) and increase insulin secretion but that these responses display different characteristics. In the case of efaroxan, the increase in cytosolic Ca(2+) was readily reversible, whereas, with harmane, the effect persisted beyond removal of the agonist and resulted in the development of a repetitive train of Ca(2+)-oscillations whose frequency, but not amplitude, was concentration-dependent. Initiation of the Ca(2+)-oscillations by harmane was independent of extracellular calcium but was sensitive to both dantrolene and high levels (20 mM) of caffeine, suggesting the involvement of ryanodine receptor-gated Ca(2+)-release. The expression of ryanodine receptor-1 and ryanodine receptor-2 mRNA in MIN6 cells was confirmed using reverse transcription-polymerase chain reaction (RT-PCR) and, since low concentrations of caffeine (1 mM) or thimerosal (10 microM) stimulated increases in [Ca(2+)](i), we conclude that ryanodine receptors are functional in these cells. Furthermore, the increase in insulin secretion induced by harmane was attenuated by dantrolene, consistent with the involvement of ryanodine receptors in mediating this response. By contrast, the smaller insulin secretory response to efaroxan was unaffected by dantrolene. Harmane-evoked changes in cytosolic Ca(2+) were maintained by nifedipine-sensitive Ca(2+)-influx, suggesting the involvement of L-type voltage-gated Ca(2+)-channels. Taken together, these data imply that harmane may interact with ryanodine receptors to generate sustained Ca(2+)-oscillations in pancreatic beta-cells and that this effect

  9. Characterization of the distal promoter of the human pyruvate carboxylase gene in pancreatic beta cells.

    Directory of Open Access Journals (Sweden)

    Ansaya Thonpho

    Full Text Available Pyruvate carboxylase (PC is an enzyme that plays a crucial role in many biosynthetic pathways in various tissues including glucose-stimulated insulin secretion. In the present study, we identify promoter usage of the human PC gene in pancreatic beta cells. The data show that in the human, two alternative promoters, proximal and distal, are responsible for the production of multiple mRNA isoforms as in the rat and mouse. RT-PCR analysis performed with cDNA prepared from human liver and islets showed that the distal promoter, but not the proximal promoter, of the human PC gene is active in pancreatic beta cells. A 1108 bp fragment of the human PC distal promoter was cloned and analyzed. It contains no TATA box but possesses two CCAAT boxes, and other putative transcription factor binding sites, similar to those of the distal promoter of rat PC gene. To localize the positive regulatory region in the human PC distal promoter, 5'-truncated and the 25-bp and 15-bp internal deletion mutants of the human PC distal promoter were generated and used in transient transfections in INS-1 832/13 insulinoma and HEK293T (kidney cell lines. The results indicated that positions -340 to -315 of the human PC distal promoter serve as (an activator element(s for cell-specific transcription factor, while the CCAAT box at -71/-67, a binding site for nuclear factor Y (NF-Y, as well as a GC box at -54/-39 of the human PC distal promoter act as activator sequences for basal transcription.

  10. Central infusion of leptin improves insulin resistance and suppresses beta-cell function, but not beta-cell mass, primarily through the sympathetic nervous system in a type 2 diabetic rat model.

    Science.gov (United States)

    Park, Sunmin; Ahn, Il Sung; Kim, Da Sol

    2010-06-05

    We investigated whether hypothalamic leptin alters beta-cell function and mass directly via the sympathetic nervous system (SNS) or indirectly as the result of altered insulin resistant states. The 90% pancreatectomized male Sprague Dawley rats had sympathectomy into the pancreas by applying phenol into the descending aorta (SNSX) or its sham operation (Sham). Each group was divided into two sections, receiving either leptin at 300ng/kgbw/h or artificial cerebrospinal fluid (aCSF) via intracerebroventricular (ICV) infusion for 3h as a short-term study. After finishing the infusion study, ICV leptin (3mug/kg bw/day) or ICV aCSF (control) was infused in rats fed 30 energy % fat diets by osmotic pump for 4weeks. At the end of the long-term study, glucose-stimulated insulin secretion and islet morphometry were analyzed. Acute ICV leptin administration in Sham rats, but not in SNSX rats, suppressed the first- and second-phase insulin secretion at hyperglycemic clamp by about 48% compared to the control. Regardless of SNSX, the 4-week administration of ICV leptin improved glucose tolerance during oral glucose tolerance tests and insulin sensitivity at hyperglycemic clamp, compared to the control, while it suppressed second-phase insulin secretion in Sham rats but not in SNSX rats. However, the pancreatic beta-cell area and mass were not affected by leptin and SNSX, though ICV leptin decreased individual beta-cell size and concomitantly increased beta-cell apoptosis in Sham rats. Leptin directly decreases insulin secretion capacity mainly through the activation of SNS without modulating pancreatic beta-cell mass.

  11. Bone morphogenetic protein 4 inhibits insulin secretion from rodent beta cells through regulation of calbindin1 expression and reduced voltage-dependent calcium currents

    DEFF Research Database (Denmark)

    Christensen, Gitte L.; Jacobsen, Maria L. B.; Wendt, Anna

    2015-01-01

    AIMS/HYPOTHESIS: Type 2 diabetes is characterised by progressive loss of pancreatic beta cell mass and function. Therefore, it is of therapeutic interest to identify factors with the potential to improve beta cell proliferation and insulin secretion. Bone morphogenetic protein 4 (BMP4) expression...

  12. Beta-cell function, incretin effect, and incretin hormones in obese youth along the span of glucose tolerance from normal to prediabetes to Type 2 diabetes

    Science.gov (United States)

    Using the hyperglycemic and euglycemic clamp, we demonstrated impaired Beta-cell function in obese youth with increasing dysglycemia. Herein we describe oral glucose tolerance test (OGTT)-modeled Beta-cell function and incretin effect in obese adolescents spanning the range of glucose tolerance. Bet...

  13. The potential role of SOCS-3 in the interleukin-1beta-induced desensitization of insulin signaling in pancreatic beta-cells

    DEFF Research Database (Denmark)

    Emanuelli, Brice; Glondu, Murielle; Filloux, Chantal

    2004-01-01

    insulin signaling is required for the optimal beta-cell function, we assessed the effect of IL-1beta on the insulin pathway in a rat pancreatic beta-cell line. We show that IL-1beta decreases insulin-induced tyrosine phosphorylation of the insulin receptor (IR) and insulin receptor substrate (IRS...

  14. High normal fasting glucose level in obese youth: a marker for insulin resistance and beta cell dysregulation.

    LENUS (Irish Health Repository)

    O'Malley, G

    2010-06-01

    A high but normal fasting plasma glucose level in adults is a risk factor for future development of type 2 diabetes mellitus and cardiovascular disease. We investigated whether normal fasting plasma glucose levels (<5.60 mmol\\/l) are associated with decreases in insulin sensitivity and beta cell function, as well as an adverse cardiovascular profile in obese youth.

  15. Pathway decision-making strategies for generating pancreatic beta-cells: systems biology or hit and miss?

    Science.gov (United States)

    Jensen, Jan

    2007-08-01

    Method selection strategies to achieve beta-cell differentiation from human embryonic stem cells are reviewed. Expectations are high for an embryonic stem cell derived cellular replacement method to cure diabetes, and recent observations indicate that mature beta-cells can be derived from human embryonic stem cells. In terms of the translational setting, however, we are not there yet; conversion of embryonic stem cells to fully mature beta-cells is not effective and does not provide an exclusive beta-cell population as the end-product. Studies emphasize that expecting development of a 'magic media bullet' that promotes endocrine fate is rather optimistic; consecutive administration of signaling inducers, carefully provided to mimic normal development, is more likely to succeed. To accomplish this task we need better understanding of the extracellular signaling pathways that drive progressive endodermal fate choices throughout development. Knowledge of cell-intrinsic control of fate assignments in pancreas is growing rapidly. Nevertheless, insufficient information regarding morphogen codes that operate in endoderm and pancreas is hindering development of better, directed differentiation schema of uncommitted embryonic stem cells toward endodermal, pancreatic, and subsequent endocrine specific fates. A systematic approach to defining morphogen codes in developing endoderm and pancreas appears timely and justified.

  16. Repetitive in vivo treatment with human recombinant interleukin-1 beta modifies beta-cell function in normal rats

    DEFF Research Database (Denmark)

    Wogensen, L D; Reimers, J; Nerup, J

    1992-01-01

    It is unknown whether interleukin-1 exerts a bimodal effect on Beta-cell function in vivo, and whether interleukin-1 has a diabetogenic action in normal animals. We therefore studied: (a) acute effects 2 h after an intraperitoneal bolus injection of 4 micrograms of recombinant human interleukin-1...

  17. Strain-dependent differences in sensitivity of rat beta-cells to interleukin 1 beta in vitro and in vivo

    DEFF Research Database (Denmark)

    Reimers, J I; Andersen, H U; Mauricio, D

    1996-01-01

    /kg) or vehicle for 5 days. All the strains investigated were susceptible to IL-1 beta-induced changes in body weight, food intake, temperature, and plasma glucagon and corticosterone. However, IL-1 beta induced hyperglycemia and impairment of beta-cell glucose responsiveness in WK/Mol and LS/Mol rats...

  18. The ectopic expression of Pax4 in the mouse pancreas converts progenitor cells into alpha and subsequently beta cells.

    Science.gov (United States)

    Collombat, Patrick; Xu, Xiaobo; Ravassard, Philippe; Sosa-Pineda, Beatriz; Dussaud, Sébastien; Billestrup, Nils; Madsen, Ole D; Serup, Palle; Heimberg, Harry; Mansouri, Ahmed

    2009-08-07

    We have previously reported that the loss of Arx and/or Pax4 gene activity leads to a shift in the fate of the different endocrine cell subtypes in the mouse pancreas, without affecting the total endocrine cell numbers. Here, we conditionally and ectopically express Pax4 using different cell-specific promoters and demonstrate that Pax4 forces endocrine precursor cells, as well as mature alpha cells, to adopt a beta cell destiny. This results in a glucagon deficiency that provokes a compensatory and continuous glucagon+ cell neogenesis requiring the re-expression of the proendocrine gene Ngn3. However, the newly formed alpha cells fail to correct the hypoglucagonemia since they subsequently acquire a beta cell phenotype upon Pax4 ectopic expression. Notably, this cycle of neogenesis and redifferentiation caused by ectopic expression of Pax4 in alpha cells is capable of restoring a functional beta cell mass and curing diabetes in animals that have been chemically depleted of beta cells.

  19. Characterization of membrane-shed micro-vesicles from cytokine-stimulated beta-cells using proteomics strategies

    DEFF Research Database (Denmark)

    Palmisano, Giuseppe; Jensen, Soren Skov; Le Bihan, Marie Catherine

    2012-01-01

    specific sites of protein phosphorylation and sialylated glycosylation in proteins associated with micro-vesicles from beta-cells. Using pathway analysis software we were able to map the most distinctive changes between micro-vesicles generated during growth and after cytokine stimulation to several cell...

  20. Pancreatic beta cell function increases in a linear dose-response manner following exercise training in adults with prediabetes

    DEFF Research Database (Denmark)

    Malin, Steven K; Solomon, Thomas; Blaszczak, Alecia

    2013-01-01

    While some studies suggest that a linear dose-response relationship exists between exercise and insulin sensitivity, the exercise dose required to enhance pancreatic beta-cell function is unknown. Thirty-five older, obese adults with prediabetes underwent a progressive 12-week supervised exercise...

  1. Inter-domain tagging implicates caveolin-1 in insulin receptor trafficking and Erk signaling bias in pancreatic beta-cells

    Directory of Open Access Journals (Sweden)

    Tobias Boothe

    2016-05-01

    Full Text Available Objective: The role and mechanisms of insulin receptor internalization remain incompletely understood. Previous trafficking studies of insulin receptors involved fluorescent protein tagging at their termini, manipulations that may be expected to result in dysfunctional receptors. Our objective was to determine the trafficking route and molecular mechanisms of functional tagged insulin receptors and endogenous insulin receptors in pancreatic beta-cells. Methods: We generated functional insulin receptors tagged with pH-resistant fluorescent proteins between domains. Confocal, TIRF and STED imaging revealed a trafficking pattern of inter-domain tagged insulin receptors and endogenous insulin receptors detected with antibodies. Results: Surprisingly, interdomain-tagged and endogenous insulin receptors in beta-cells bypassed classical Rab5a- or Rab7-mediated endocytic routes. Instead, we found that removal of insulin receptors from the plasma membrane involved tyrosine-phosphorylated caveolin-1, prior to trafficking within flotillin-1-positive structures to lysosomes. Multiple methods of inhibiting caveolin-1 significantly reduced Erk activation in vitro or in vivo, while leaving Akt signaling mostly intact. Conclusions: We conclude that phosphorylated caveolin-1 plays a role in insulin receptor internalization towards lysosomes through flotillin-1-positive structures and that caveolin-1 helps bias physiological beta-cell insulin signaling towards Erk activation. Author Video: Author Video Watch what authors say about their articles Keywords: Insulin receptor internalization, Insulin resistance, Pancreatic islet beta-cells, Autocrine insulin signaling

  2. Alkali pH directly activates ATP-sensitive K+ channels and inhibits insulin secretion in beta-cells.

    Science.gov (United States)

    Manning Fox, Jocelyn E; Karaman, Gunce; Wheeler, Michael B

    2006-11-17

    Glucose stimulation of pancreatic beta-cells is reported to lead to sustained alkalization, while extracellular application of weak bases is reported to inhibit electrical activity and decrease insulin secretion. We hypothesize that beta-cell K(ATP) channel activity is modulated by alkaline pH. Using the excised patch-clamp technique, we demonstrate a direct stimulatory action of alkali pH on recombinant SUR1/Kir6.2 channels due to increased open probability. Bath application of alkali pH similarly activates native islet beta-cell K(ATP) channels, leading to an inhibition of action potentials, and hyperpolarization of membrane potential. In situ pancreatic perfusion confirms that these cellular effects of alkali pH are observable at a functional level, resulting in decreases in both phase 1 and phase 2 glucose-stimulated insulin secretion. Our data are the first to report a stimulatory effect of a range of alkali pH on K(ATP) channel activity and link this to downstream effects on islet beta-cell function.

  3. Do immunotherapy and beta cell replacement play a synergistic role in the treatment of type 1 diabetes?

    Science.gov (United States)

    Li, Dong-Sheng; Warnock, Garth L; Tu, Han-Jun; Ao, Ziliang; He, Zehua; Lu, Hong; Dai, Long-Jun

    2009-10-07

    Type 1 diabetes (T1D) is the result of the autoimmune response against pancreatic insulin-producing ss-cells. Its ultimate consequence is beta-cell insufficiency-mediated dysregulation of blood glucose control. In terms of T1D treatment, immunotherapy addresses the cause of T1D, mainly through re-setting the balance between autoimmunity and regulatory mechanisms. Regulatory T cells play an important role in this immune intervention. An alternative T1D treatment is beta-cell replacement, which can reverse the consequence of the disease by replacing destroyed beta-cells in the diabetic pancreas. The applicable insulin-producing cells can be directly obtained from islet transplantation or generated from other cell sources such as autologous adult stem cells, embryonic stem cells, and induced pluripotent stem cells. In this review, we summarize the recent research progress and analyze the possible advantages and disadvantages of these two therapeutic options especially focusing on the potential synergistic effect on T1D treatment. Exploring the optimal combination of immunotherapy and beta-cell replacement will pave the way to the most effective cure for this devastating disease.

  4. Rising Intracellular Zinc by Membrane Depolarization and Glucose in Insulin-Secreting Clonal HIT-T15 Beta Cells

    Directory of Open Access Journals (Sweden)

    Kira G. Slepchenko

    2012-01-01

    Full Text Available Zinc (Zn2+ appears to be intimately involved in insulin metabolism since insulin secretion is correlated with zinc secretion in response to glucose stimulation, but little is known about the regulation of zinc homeostasis in pancreatic beta-cells. This study set out to identify the intracellular zinc transient by imaging free cytosolic zinc in HIT-T15 beta-cells with fluorescent zinc indicators. We observed that membrane depolarization by KCl (30–60 mM was able to induce a rapid increase in cytosolic concentration of zinc. Multiple zinc transients of similar magnitude were elicited during repeated stimulations. The amplitude of zinc responses was not affected by the removal of extracellular calcium or zinc. However, the half-time of the rising slope was significantly slower after removing extracellular zinc with zinc chelator CaEDTA, suggesting that extracellular zinc affect the initial rising phase of zinc response. Glucose (10 mM induced substantial and progressive increases in intracellular zinc concentration in a similar way as KCl, with variation in the onset and the duration of zinc mobilization. It is known that the depolarization of beta-cell membrane is coupled with the secretion of insulin. Rising intracellular zinc concentration may act as a critical signaling factor in insulin metabolism of pancreatic beta-cells.

  5. Rising intracellular zinc by membrane depolarization and glucose in insulin-secreting clonal HIT-T15 beta cells.

    Science.gov (United States)

    Slepchenko, Kira G; Li, Yang V

    2012-01-01

    Zinc (Zn(2+)) appears to be intimately involved in insulin metabolism since insulin secretion is correlated with zinc secretion in response to glucose stimulation, but little is known about the regulation of zinc homeostasis in pancreatic beta-cells. This study set out to identify the intracellular zinc transient by imaging free cytosolic zinc in HIT-T15 beta-cells with fluorescent zinc indicators. We observed that membrane depolarization by KCl (30-60 mM) was able to induce a rapid increase in cytosolic concentration of zinc. Multiple zinc transients of similar magnitude were elicited during repeated stimulations. The amplitude of zinc responses was not affected by the removal of extracellular calcium or zinc. However, the half-time of the rising slope was significantly slower after removing extracellular zinc with zinc chelator CaEDTA, suggesting that extracellular zinc affect the initial rising phase of zinc response. Glucose (10 mM) induced substantial and progressive increases in intracellular zinc concentration in a similar way as KCl, with variation in the onset and the duration of zinc mobilization. It is known that the depolarization of beta-cell membrane is coupled with the secretion of insulin. Rising intracellular zinc concentration may act as a critical signaling factor in insulin metabolism of pancreatic beta-cells.

  6. Proinsulin maturation disorder is a contributor to the defect of subsequent conversion to insulin in {beta}-cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jie, E-mail: jie.wang2@osumc.edu [Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, The Ohio State University, Columbus, OH (United States); Osei, Kwame [Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, The Ohio State University, Columbus, OH (United States)

    2011-07-22

    Highlights: {yields} Primary proinsulin maturation disorder is inherent in Ins2{sup +/Akita} islets/{beta}-cells. {yields} A consequence is the inefficient conversion of proinsulin to insulin. {yields} Post-translational defects occur as well in the involved PC1/3 and PC2 convertases. {yields} Proinsulin maturation chaos results in defects in the following conversion process. {yields} A link of the proinsulin maturation disorder and hyperproinsulinemia is suggested. -- Abstract: Disproportionate hyperproinsulinemia is an indicator of {beta}-cell dysfunction in diabetes and the basis underlying this abnormality remains obscure. Recently, we have found proinsulin is an aggregation-prone molecule inherent with a low relative folding rate and maintains a homeostatic balance of natively and plentiful non-natively folded states (i.e., proinsulin homeostasis, PIHO) in normal {beta}-cells as a result of the integration of maturation and disposal processes. PIHO is susceptible to environmental and genetic influences. Perturbation of PIHO produces a number of toxic consequences with known association to {beta}-cell failure in diabetes. To explore whether the perturbation of PIHO has a link to disproportionate hyperproinsulinemia, we investigated proinsulin conversion and the involved prohormone convertase 1/3 (PC1/3) and 2 (PC2) in mouse Ins2{sup +/Akita} islets/{beta}-cells that preserve a primary PIHO disorder due to a mutation (C96Y) in the insulin 2 (Ins2) gene. Our metabolic-labeling studies found an increased ratio of proinsulin to insulin in the cellular or released proteins of Ins2{sup +/Akita} islets. Histological, metabolic-labeling, and RT-PCR analyses revealed decreases of the PC1/3 and PC2 immunoreactivities in the {beta}-cells of Ins2{sup +/Akita} islets in spite of no declines of these two convertases at the transcriptional and translational levels. Immunoblot analyses in cloned Ins2{sup +/Akita} {beta}-cells further confirmed the increased ratio of proinsulin

  7. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells.

    Science.gov (United States)

    Pavlikova, Nela; Smetana, Pavel; Halada, Petr; Kovar, Jan

    2015-10-01

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Stevioside improves pancreatic beta-cell function during glucotoxicity via regulation of acetyl-CoA carboxylase.

    Science.gov (United States)

    Chen, Jianguo; Jeppesen, Per Bendix; Nordentoft, Iver; Hermansen, Kjeld

    2007-06-01

    Chronic hyperglycemia is detrimental to pancreatic beta-cells, causing impaired insulin secretion and beta-cell turnover. The characteristic secretory defects are increased basal insulin secretion (BIS) and a selective loss of glucose-stimulated insulin secretion (GSIS). Several recent studies support the view that the acetyl-CoA carboxylase (ACC) plays a pivotal role for GSIS. We have shown that stevioside (SVS) enhances insulin secretion and ACC gene expression. Whether glucotoxicity influences ACC and whether this action can be counteracted by SVS are not known. To investigate this, we exposed isolated mouse islets as well as clonal INS-1E beta-cells for 48 h to 27 or 16.7 mM glucose, respectively. We found that 48-h exposure to high glucose impairs GSIS from mouse islets and INS-1E cells, an effect that is partly counteracted by SVS. The ACC dephosphorylation inhibitor okadaic acid (OKA, 10(-8) M), and 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside (AICAR, 10(-4) M), an activator of 5'-AMP protein kinase that phosphorylates ACC, eliminated the beneficial effect of SVS. 5-Tetrade-cyloxy-2-furancarboxylic acid (TOFA), the specific ACC inhibitor, blocked the effect of SVS as well. During glucotoxity, ACC gene expression, ACC protein, and phosphorylated ACC protein were increased in INS-1E beta-cells. SVS pretreatment further increased ACC gene expression with strikingly elevated ACC activity and increased glucose uptake accompanied by enhanced GSIS. Our studies show that glucose is a potent stimulator of ACC and that SVS to some extent counteracts glucotoxicity via increased ACC activity. SVS possesses the potential to alleviate negative effects of glucotoxicity in beta-cells via a unique mechanism of action.

  9. PARP-1 and YY1 are important novel regulators of CXCL12 gene transcription in rat pancreatic beta cells.

    Directory of Open Access Journals (Sweden)

    Jelena Marković

    Full Text Available Despite significant progress, the molecular mechanisms responsible for pancreatic beta cell depletion and development of diabetes remain poorly defined. At present, there is no preventive measure against diabetes. The positive impact of CXCL12 expression on the pancreatic beta cell prosurvival phenotype initiated this study. Our aim was to provide novel insight into the regulation of rat CXCL12 gene (Cxcl12 transcription. The roles of poly(ADP-ribose polymerase-1 (PARP-1 and transcription factor Yin Yang 1 (YY1 in Cxcl12 transcription were studied by examining their in vitro and in vivo binding affinities for the Cxcl12 promoter in a pancreatic beta cell line by the electrophoretic mobility shift assay and chromatin immunoprecipitation. The regulatory activities of PARP-1 and YY1 were assessed in transfection experiments using a reporter vector with a Cxcl12 promoter sequence driving luciferase gene expression. Experimental evidence for PARP-1 and YY1 revealed their trans-acting potential, wherein PARP-1 displayed an inhibitory, and YY1 a strong activating effect on Cxcl12 transcription. Streptozotocin (STZ-induced general toxicity in pancreatic beta cells was followed by changes in Cxcl12 promoter regulation. PARP-1 binding to the Cxcl12 promoter during basal and in STZ-compromised conditions led us to conclude that PARP-1 regulates constitutive Cxcl12 expression. During the early stage of oxidative stress, YY1 exhibited less affinity toward the Cxcl12 promoter while PARP-1 displayed strong binding. These interactions were accompanied by Cxcl12 downregulation. In the later stages of oxidative stress and intensive pancreatic beta cell injury, YY1 was highly expressed and firmly bound to Cxcl12 promoter in contrast to PARP-1. These interactions resulted in higher Cxcl12 expression. The observed ability of PARP-1 to downregulate, and of YY1 to upregulate Cxcl12 promoter activity anticipates corresponding effects in the natural context where the

  10. Adult Human Pancreatic Islet Beta-Cells Display Limited Turnover and Long Lifespan as Determined by In-Vivo Thymidine Analog Incorporation and Radiocarbon Dating

    Energy Technology Data Exchange (ETDEWEB)

    Perl, S; Kushner, J A; Buchholz, B A; Meeker, A K; Stein, G M; Hsieh, M; Kirby, M; Pechhold, S; Liu, E H; Harlan, D M; Tisdale, J F

    2010-03-15

    Diabetes mellitus results from an absolute or relative deficiency of insulin producing pancreatic beta-cells. The adult human beta-cell's turnover rate remains unknown. We employed novel techniques to examine adult human islet beta-cell turnover and longevity in vivo. Subjects enrolled in NIH clinical trials received thymidine analogues [iododeoxyuridine (IdU) or bromodeoxyuridine (BrdU)] 8-days to 4-years prior to death. Archival autopsy samples from ten patients (aged 17-74 years) were employed to assess beta-cell turnover by scoring nuclear analog labeling within insulin staining cells. Human adult beta-cell longevity was determined by estimating the cells genomic DNA integration of atmospheric carbon-14 ({sup 14}C). DNA was purified from pancreatic islets isolated from cadaveric donors; whole islet prep DNA was obtained from a 15 year old donor, and purified beta-cell DNA was obtained from two donors (age 48 and 80 years). {sup 14}C levels were then determined using accelerator mass spectrometry (AMS). Cellular 'birth date' was determined by comparing the subject's DNA {sup 14}C content relative to a well-established {sup 14}C atmospheric prevalence curve. In the two subjects less than age 20 years, 1-2% of the beta-cell nuclei co-stained for BrdU/IdU. No beta-cell nuclei co-stained in the eight patients more than 30 years old. Consistent with the BrdU/IdU turnover data, beta-cell DNA {sup 14}C content indicated the cells 'birth date' occurred within the subject's first 30 years of life. Under typical circumstances, adult human beta-cells and their cellular precursors are established by young adulthood.

  11. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells

    Energy Technology Data Exchange (ETDEWEB)

    Pavlikova, Nela, E-mail: nela.pavlikova@lf3.cuni.cz [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic); Smetana, Pavel [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic); Halada, Petr [Laboratory of Molecular Structure Characterization, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague (Czech Republic); Kovar, Jan [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic)

    2015-10-15

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. - Highlights: • Epidemiologic studies connect pollution with incidence of diabetes mellitus. • We explored the effect of DDT and DDE on protein expression in the NES2Y pancreatic beta cell line. • One month exposure to three sublethal concentrations of DDT and DDE was employed. • Expression of alpha-enolase, actin

  12. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells

    International Nuclear Information System (INIS)

    Pavlikova, Nela; Smetana, Pavel; Halada, Petr; Kovar, Jan

    2015-01-01

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. - Highlights: • Epidemiologic studies connect pollution with incidence of diabetes mellitus. • We explored the effect of DDT and DDE on protein expression in the NES2Y pancreatic beta cell line. • One month exposure to three sublethal concentrations of DDT and DDE was employed. • Expression of alpha-enolase, actin

  13. Profile of blood glucose and ultrastucture of beta cells pancreatic islet in alloxan compound induced rats

    Directory of Open Access Journals (Sweden)

    I Nyoman Suarsana

    2010-06-01

    Full Text Available Diabetes is marked by elevated levels of blood glucose, and progressive changes of the structure of pancreatic islet histopathology. The objective of this research was to analyse the glucose level and histophatological feature in pancreatic islet in alloxan compound induced rats. A total of ten male Spraque Dawley rats of 2 months old were used in this study. The rats were divided into two groups: (1 negative control group (K-, and (2 positif induced alloxan group (diabetic group =DM. The rats were induced by a single dose intraperitonial injection of alloxan compound 120 mg/kg of body weight. The treatment was conducted for 28 days. Blood glucose levels of rats were analysed at 0, 4, 7, 14, 21, and 28 days following treatment. At the end of the experiment, rats were sacrificed by cervical dislocation. Pancreas was collected for analysis of histopathological study by Immunohistochemical technique, and ultrastructural study using transmission electron microscope (TEM. The result showed that Langerhans islet of diabetic rat (rat of DM group showed a marked reduction of size, number of Langerhans islet of diabetic rat decrease, and characterized by hyperglycemic condition. By using TEM, beta cells of DM group showed the rupture of mitochondrial membrane, the lost of cisternal structure of inner membrane of mitocondria, reduction of insulin secretory granules, linkage between cells acinar with free Langerhans islet, and the caryopicnotic of nucleus.

  14. GTP- and GDP-Dependent Rab27a Effectors in Pancreatic Beta-Cells.

    Science.gov (United States)

    Yamaoka, Mami; Ishizaki, Toshimasa; Kimura, Toshihide

    2015-01-01

    Small guanosine triphosphatases (GTPases) participate in a wide variety of cellular functions including proliferation, differentiation, adhesion, and intracellular transport. Conventionally, only the guanosine 5'-triphosphate (GTP)-bound small GTPase interacts with effector proteins, and the resulting downstream signals control specific cellular functions. Therefore, the GTP-bound form is regarded as active, and the focus has been on searching for proteins that bind the GTP form to look for their effectors. The Rab family small GTPase Rab27a is highly expressed in some secretory cells and is involved in the control of membrane traffic. The present study reviews recent progress in our understanding of the roles of Rab27a and its effectors in pancreatic beta-cells. In the basal state, GTP-bound Rab27a controls insulin secretion at pre-exocytic stages via its GTP-dependent effectors. We previously identified novel guanosine 5'-diphosphate (GDP)-bound Rab27-interacting proteins. Interestingly, GDP-bound Rab27a controls endocytosis of the secretory membrane via its interaction with these proteins. We also demonstrated that the insulin secretagogue glucose converts Rab27a from its GTP- to GDP-bound forms. Thus, GTP- and GDP-bound Rab27a regulate pre-exocytic and endocytic stages in membrane traffic, respectively. Since the physiological importance of GDP-bound GTPases has been largely overlooked, we consider that the investigation of GDP-dependent effectors for other GTPases is necessary for further understanding of cellular function.

  15. Longitudinal Changes in Insulin Resistance, Beta-Cell Function and Glucose Regulation Status in Prediabetes.

    Science.gov (United States)

    Kim, Chul-Hee; Kim, Hong-Kyu; Kim, Eun-Hee; Bae, Sung-Jin; Choe, Jaewon; Park, Joong-Yeol

    2018-01-01

    The changes in insulin resistance and insulin secretion and their association with changes in glucose regulation status in Asians with prediabetes remain uncertain. We included Korean adults (aged 20-79 years) with prediabetes who underwent routine medical check-ups at a mean interval of 5 years. Prediabetes was defined as fasting plasma glucose (FPG) 5.6-6.9mmol/l or HbA1c 5.7-6.4% (39-46mmol/mol). Insulin resistance (HOMA-IR) and beta-cell function (HOMA-%B) indices were assessed by homeostasis model assessment. Incident diabetes was defined as FPG ≥ 7.0mmol/l, HbA1c ≥ 6.5% (48mmol/mol), or initiation of antidiabetic medications. Among the 7,208 participants with prediabetes, 4,410 (61.2%) remained as prediabetes (control group), 2,123 (29.5%) reverted to normal glucose regulation (regressors), and 675 (9.4%) progressed to type 2 diabetes (progressors) after 5 years. Compared with the control group, the progressors had higher baseline HOMA-IR (2.48 ± 1.45 versus 2.06 ± 1.20, P prediabetes, longitudinal change in insulin resistance was the predominant factor in Koreans. Copyright © 2018 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

  16. Oxidative Stress Type Influences the Properties of Antioxidants Containing Polyphenols in RINm5F Beta Cells

    Directory of Open Access Journals (Sweden)

    Nathalie Auberval

    2015-01-01

    Full Text Available The in vitro methods currently used to screen bioactive compounds focus on the use of a single model of oxidative stress. However, this simplistic view may lead to conflicting results. The aim of this study was to evaluate the antioxidant properties of two natural extracts (a mix of red wine polyphenols (RWPs and epigallocatechin gallate (EGCG with three models of oxidative stress induced with hydrogen peroxide (H2O2, a mixture of hypoxanthine and xanthine oxidase (HX/XO, or streptozotocin (STZ in RINm5F beta cells. We employed multiple approaches to validate their potential as therapeutic treatment options, including cell viability, reactive oxygen species production, and antioxidant enzymes expression. All three oxidative stresses induced a decrease in cell viability and an increase in apoptosis, whereas the level of ROS production was variable depending on the type of stress. The highest level of ROS was found for the HX/XO-induced stress, an increase that was reflected by higher expression antioxidant enzymes. Further, both antioxidant compounds presented beneficial effects during oxidative stress, but EGCG appeared to be a more efficient antioxidant. These data indicate that the efficiency of natural antioxidants is dependent on both the nature of the compound and the type of oxidative stress generated.

  17. Measuring phospholipase D activity in insulin-secreting pancreatic beta-cells and insulin-responsive muscle cells and adipocytes.

    Science.gov (United States)

    Cazzolli, Rosanna; Huang, Ping; Teng, Shuzhi; Hughes, William E

    2009-01-01

    Phospholipase D (PLD) is an enzyme producing phosphatidic acid and choline through hydrolysis of phosphatidylcholine. The enzyme has been identified as a member of a variety of signal transduction cascades and as a key regulator of numerous intracellular vesicle trafficking processes. A role for PLD in regulating glucose homeostasis is emerging as the enzyme has recently been identified in events regulating exocytosis of insulin from pancreatic beta-cells and also in insulin-stimulated glucose uptake through controlling GLUT4 vesicle exocytosis in muscle and adipose tissue. We present methodologies for assessing cellular PLD activity in secretagogue-stimulated insulin-secreting pancreatic beta-cells and also insulin-stimulated adipocyte and muscle cells, two of the principal insulin-responsive cell types controlling blood glucose levels.

  18. Impaired beta cell sensitivity to incretins in type 2 diabetes is insufficiently compensated by higher incretin response

    DEFF Research Database (Denmark)

    Tura, A.; Bagger, J. I.; Ferrannini, E.

    2017-01-01

    Background and aims The incretin effect is impaired in type 2 diabetes (T2D), but the underlying mechanisms are only partially understood. We investigated the relationships between the time course of the incretin effect and that of glucose-dependent insulinotropic polypeptide (GIP) and glucagon......-like peptide-1 (GLP-1) during oral glucose tolerance tests (OGTTs), thereby estimating incretin sensitivity of the beta cell, and its associated factors. Methods and results Eight patients with T2D and eight matched subjects with normal glucose tolerance (NGT) received 25, 75, and 125 g OGTTs and corresponding...... was correlated with that of both GIP and GLP-1 in each subject (median r = 0.67 in NGT and 0.45 in T2D). We calculated an individual beta cell sensitivity to incretins (SINCR) using a weighted average of GIP and GLP-1 (pooled incretin concentration, PIC), as the slope of the relationship between PINCR and PIC...

  19. Insulin resistance and beta-cell function in different ethnic groups in Kenya: the role of abdominal fat distribution

    DEFF Research Database (Denmark)

    Christensen, D.L.; Faurholt-Jepsen, D.; Faerch, K.

    2014-01-01

    Little is known about the pathophysiology of diabetes in Africans. Thus, we assessed whether insulin resistance and beta-cell function differed by ethnicity in Kenya and whether differences were modified by abdominal fat distribution. A cross-sectional study in 1,087 rural Luo (n = 361), Kamba (n...... to the Luo and Kamba, respectively. Adjustments of SAT (range 0.1–7.1 cm) and VAT (range 1.5–14.2 cm) largely explained these inter-group differences with the Maasai having the highest combined abdominal fat accumulation. The Maasai had the highest insulin resistance and secretion, but the lowest relative...... beta-cell function compared to the Luo and Kamba. These differences were primarily explained by abdominal fat distribution....

  20. Role of transcription factor KLF11 and its diabetes-associated gene variants in pancreatic beta cell function

    DEFF Research Database (Denmark)

    Neve, Bernadette; Fernandez-Zapico, Martin E; Ashkenazi-Katalan, Vered

    2005-01-01

    in beta cells. Genetic analysis of the KLF11 gene revealed two rare variants (Ala347Ser and Thr220Met) that segregate with diabetes in families with early-onset type 2 diabetes, and significantly impair its transcriptional activity. In addition, analysis of 1,696 type 2 diabetes mellitus and 1......,776 normoglycemic subjects show a frequent polymorphic Gln62Arg variant that significantly associates with type 2 diabetes mellitus in North European populations (OR = 1.29, P = 0.00033). Moreover, this variant alters the corepressor mSin3A-binding activity of KLF11, impairs the activation of the insulin promoter...... and shows lower levels of insulin expression in pancreatic beta cells. In addition, subjects carrying the Gln62Arg allele show decreased plasma insulin after an oral glucose challenge. Interestingly, all three nonsynonymous KLF11 variants show increased repression of the catalase 1 promoter, suggesting...

  1. Phenotypic and gene expression changes between low (glucose-responsive) and High (glucose non-responsive) MIN-6 beta cells

    DEFF Research Database (Denmark)

    O´Driscoll, L.; Gammell, p.; McKierman, E.

    2006-01-01

    The long-term potential to routinely use replacement beta cells/islets as cell therapy for type 1 diabetes relies on our ability to culture such cells/islets, in vitro, while maintaining their functional status. Previous beta cell studies, by ourselves and other researchers, have indicated...... that the glucose-stimulated insulin secretion (GSIS) phenotype is relatively unstable, in long-term culture. This study aimed to investigate phenotypic and gene expression changes associated with this loss of GSIS, using the MIN-6 cell line as model. Phenotypic differences between MIN-6(L, low passage) and MIN-6(H......, high passage) were determined by ELISA (assessing GSIS and cellular (pro)insulin content), proliferation assays, phase contrast light microscopy and analysis of alkaline phosphatase expression. Differential mRNA expression was investigated using microarray, bioinformatics and real-time PCR technologies...

  2. Metabolomic and proteomic analysis of a clonal insulin-producing beta-cell line (INS-1 832/13).

    Science.gov (United States)

    Fernandez, Céline; Fransson, Ulrika; Hallgard, Elna; Spégel, Peter; Holm, Cecilia; Krogh, Morten; Wårell, Kristofer; James, Peter; Mulder, Hindrik

    2008-01-01

    Metabolites generated from fuel metabolism in pancreatic beta-cells control exocytosis of insulin, a process which fails in type 2 diabetes. To identify and quantify these metabolites, global and unbiased analysis of cellular metabolism is required. To this end, polar metabolites, extracted from the clonal 832/13 beta-cell line cultured at 2.8 and 16.7 mM glucose for 48 h, were derivatized followed by identification and quantification, using gas chromatography (GC) and mass spectrometry (MS). After culture at 16.7 mM glucose for 48 h, 832/13 beta-cells exhibited a phenotype reminiscent of glucotoxicity with decreased content and secretion of insulin. The metabolomic analysis revealed alterations in the levels of 7 metabolites derived from glycolysis, the TCA cycle and pentose phosphate shunt, and 4 amino acids. Principal component analysis of the metabolite data showed two clusters, corresponding to the cells cultured at 2.8 and 16.7 mM glucose, respectively. Concurrent changes in protein expression were analyzed by 2-D gel electrophoresis followed by LC-MS/MS. The identities of 86 spots corresponding to 75 unique proteins that were significantly different in 832/13 beta-cells cultured at 16.7 mM glucose were established. Only 5 of these were found to be metabolic enzymes that could be involved in the metabolomic alterations observed. Anticipated changes in metabolite levels in cells exposed to increased glucose were observed, while changes in enzyme levels were much less profound. This suggests that substrate availability, allosteric regulation, and/or post-translational modifications are more important determinants of metabolite levels than enzyme expression at the protein level.

  3. Pancreas-Specific Sirt1-Deficiency in Mice Compromises Beta-Cell Function without Development of Hyperglycemia.

    Science.gov (United States)

    Pinho, Andreia V; Bensellam, Mohammed; Wauters, Elke; Rees, Maxine; Giry-Laterriere, Marc; Mawson, Amanda; Ly, Le Quan; Biankin, Andrew V; Wu, Jianmin; Laybutt, D Ross; Rooman, Ilse

    2015-01-01

    Sirtuin 1 (Sirt1) has been reported to be a critical positive regulator of glucose-stimulated insulin secretion in pancreatic beta-cells. The effects on islet cells and blood glucose levels when Sirt1 is deleted specifically in the pancreas are still unclear. This study examined islet glucose responsiveness, blood glucose levels, pancreatic islet histology and gene expression in Pdx1Cre; Sirt1ex4F/F mice that have loss of function and loss of expression of Sirt1 specifically in the pancreas. We found that in the Pdx1Cre; Sirt1ex4F/F mice, the relative insulin positive area and the islet size distribution were unchanged. However, beta-cells were functionally impaired, presenting with lower glucose-stimulated insulin secretion. This defect was not due to a reduced expression of insulin but was associated with a decreased expression of the glucose transporter Slc2a2/Glut2 and of the Glucagon like peptide-1 receptor (Glp1r) as well as a marked down regulation of endoplasmic reticulum (ER) chaperones that participate in the Unfolded Protein Response (UPR) pathway. Counter intuitively, the Sirt1-deficient mice did not develop hyperglycemia. Pancreatic polypeptide (PP) cells were the only other islet cells affected, with reduced numbers in the Sirt1-deficient pancreas. This study provides new mechanistic insights showing that beta-cell function in Sirt1-deficient pancreas is affected due to altered glucose sensing and deregulation of the UPR pathway. Interestingly, we uncovered a context in which impaired beta-cell function is not accompanied by increased glycemia. This points to a unique compensatory mechanism. Given the reduction in PP, investigation of its role in the control of blood glucose is warranted.

  4. Pancreas-Specific Sirt1-Deficiency in Mice Compromises Beta-Cell Function without Development of Hyperglycemia.

    Directory of Open Access Journals (Sweden)

    Andreia V Pinho

    Full Text Available Sirtuin 1 (Sirt1 has been reported to be a critical positive regulator of glucose-stimulated insulin secretion in pancreatic beta-cells. The effects on islet cells and blood glucose levels when Sirt1 is deleted specifically in the pancreas are still unclear.This study examined islet glucose responsiveness, blood glucose levels, pancreatic islet histology and gene expression in Pdx1Cre; Sirt1ex4F/F mice that have loss of function and loss of expression of Sirt1 specifically in the pancreas.We found that in the Pdx1Cre; Sirt1ex4F/F mice, the relative insulin positive area and the islet size distribution were unchanged. However, beta-cells were functionally impaired, presenting with lower glucose-stimulated insulin secretion. This defect was not due to a reduced expression of insulin but was associated with a decreased expression of the glucose transporter Slc2a2/Glut2 and of the Glucagon like peptide-1 receptor (Glp1r as well as a marked down regulation of endoplasmic reticulum (ER chaperones that participate in the Unfolded Protein Response (UPR pathway. Counter intuitively, the Sirt1-deficient mice did not develop hyperglycemia. Pancreatic polypeptide (PP cells were the only other islet cells affected, with reduced numbers in the Sirt1-deficient pancreas.This study provides new mechanistic insights showing that beta-cell function in Sirt1-deficient pancreas is affected due to altered glucose sensing and deregulation of the UPR pathway. Interestingly, we uncovered a context in which impaired beta-cell function is not accompanied by increased glycemia. This points to a unique compensatory mechanism. Given the reduction in PP, investigation of its role in the control of blood glucose is warranted.

  5. AMP-activated protein kinase (AMPK mediates nutrient regulation of thioredoxin-interacting protein (TXNIP in pancreatic beta-cells.

    Directory of Open Access Journals (Sweden)

    Maayan Shaked

    Full Text Available Thioredoxin-interacting protein (TXNIP regulates critical biological processes including inflammation, stress and apoptosis. TXNIP is upregulated by glucose and is a critical mediator of hyperglycemia-induced beta-cell apoptosis in diabetes. In contrast, the saturated long-chain fatty acid palmitate, although toxic to the beta-cell, inhibits TXNIP expression. The mechanisms involved in the opposing effects of glucose and fatty acids on TXNIP expression are unknown. We found that both palmitate and oleate inhibited TXNIP in a rat beta-cell line and islets. Palmitate inhibition of TXNIP was independent of fatty acid beta-oxidation or esterification. AMP-activated protein kinase (AMPK has an important role in cellular energy sensing and control of metabolic homeostasis; therefore we investigated its involvement in nutrient regulation of TXNIP. As expected, glucose inhibited whereas palmitate stimulated AMPK. Pharmacologic activators of AMPK mimicked fatty acids by inhibiting TXNIP. AMPK knockdown increased TXNIP expression in presence of high glucose with and without palmitate, indicating that nutrient (glucose and fatty acids effects on TXNIP are mediated in part via modulation of AMPK activity. TXNIP is transcriptionally regulated by carbohydrate response element-binding protein (ChREBP. Palmitate inhibited glucose-stimulated ChREBP nuclear entry and recruitment to the Txnip promoter, thereby inhibiting Txnip transcription. We conclude that AMPK is an important regulator of Txnip transcription via modulation of ChREBP activity. The divergent effects of glucose and fatty acids on TXNIP expression result in part from their opposing effects on AMPK activity. In light of the important role of TXNIP in beta-cell apoptosis, its inhibition by fatty acids can be regarded as an adaptive/protective response to glucolipotoxicity. The finding that AMPK mediates nutrient regulation of TXNIP may have important implications for the pathophysiology and treatment

  6. Role of transcription factor KLF11 and its diabetes-associated gene variants in pancreatic beta cell function

    Science.gov (United States)

    Neve, Bernadette; Fernandez-Zapico, Martin E.; Ashkenazi-Katalan, Vered; Dina, Christian; Hamid, Yasmin H.; Joly, Erik; Vaillant, Emmanuel; Benmezroua, Yamina; Durand, Emmanuelle; Bakaher, Nicolas; Delannoy, Valerie; Vaxillaire, Martine; Cook, Tiffany; Dallinga-Thie, Geesje M.; Jansen, Hans; Charles, Marie-Aline; Clément, Karine; Galan, Pilar; Hercberg, Serge; Helbecque, Nicole; Charpentier, Guillaume; Prentki, Marc; Hansen, Torben; Pedersen, Oluf; Urrutia, Raul; Melloul, Danielle; Froguel, Philippe

    2005-01-01

    KLF11 (TIEG2) is a pancreas-enriched transcription factor that has elicited significant attention because of its role as negative regulator of exocrine cell growth in vitro and in vivo. However, its functional role in the endocrine pancreas remains to be established. Here, we report, for the first time, to our knowledge, the characterization of KLF11 as a glucose-inducible regulator of the insulin gene. A combination of random oligonucleotide binding, EMSA, luciferase reporter, and chromatin immunoprecipitation assays shows that KLF11 binds to the insulin promoter and regulates its activity in beta cells. Genetic analysis of the KLF11 gene revealed two rare variants (Ala347Ser and Thr220Met) that segregate with diabetes in families with early-onset type 2 diabetes, and significantly impair its transcriptional activity. In addition, analysis of 1,696 type 2 diabetes mellitus and 1,776 normoglycemic subjects show a frequent polymorphic Gln62Arg variant that significantly associates with type 2 diabetes mellitus in North European populations (OR = 1.29, P = 0.00033). Moreover, this variant alters the corepressor mSin3A-binding activity of KLF11, impairs the activation of the insulin promoter and shows lower levels of insulin expression in pancreatic beta cells. In addition, subjects carrying the Gln62Arg allele show decreased plasma insulin after an oral glucose challenge. Interestingly, all three nonsynonymous KLF11 variants show increased repression of the catalase 1 promoter, suggesting a role in free radical clearance that may render beta cells more sensitive to oxidative stress. Thus, both functional and genetic analyses reveal that KLF11 plays a role in the regulation of pancreatic beta cell physiology, and its variants may contribute to the development of diabetes. PMID:15774581

  7. Activation of the Wnt/β-catenin pathway in pancreatic beta cells during the compensatory islet hyperplasia in prediabetic mice

    International Nuclear Information System (INIS)

    Maschio, D.A.; Oliveira, R.B.; Santos, M.R.; Carvalho, C.P.F.; Barbosa-Sampaio, H.C.L.; Collares-Buzato, C.B.

    2016-01-01

    The Wnt/β-catenin signaling pathway, also known as the canonical Wnt pathway, plays a role in cell proliferation and differentiation in several tissues/organs. It has been recently described in humans a relationship between type 2 diabetes (T2DM) and mutation in the gene encoding the transcription factor TCF7L2 associated to the Wnt/β-catenin pathway. In the present study, we demonstrated that hyperplastic pancreatic islets from prediabetic mice fed a high-fat diet (HFD) for 60 d displayed nuclear translocation of active β-catenin associated with significant increases in protein content and gene expression of β-catenin as well as of cyclins D1, D2 and c-Myc (target genes of the Wnt pathway) but not of Tcf7l2 (the transcription factor). Meanwhile, these alterations were not observed in pancreatic islets from 30 d HFD-fed mice, that do not display significant beta cell hyperplasia. These data suggest that the Wnt/β-catenin pathway is activated in pancreatic islets during prediabetes and may play a role in the induction of the compensatory beta cell hyperplasia observed at early phase of T2DM. - Highlights: • Exposure to high-fat diet for 60 days induced prediabetes and beta cell mass expansion. • Hyperplastic pancreatic islets displayed nuclear translocation of active β-catenin. • Hyperplastic islets showed increased expression of target genes of the Wnt/β-catenin pathway. • Wnt/β-catenin pathway is activated during compensatory beta cell hyperplasia in mice.

  8. Effects of low intensity laser acupoint irradiation on inhibiting islet beta-cell apoptosis in rats with type 2 diabetes

    Science.gov (United States)

    Xiong, Guoxin; Xiong, Leilei; Li, Xinzhong

    2016-09-01

    To investigate the effects of low intensity semiconductor laser acupoint irradiation on inhibiting islet beta-cell apoptosis in rats with type 2 diabetes, a method using a high-fat diet and low-dose intraperitoneal injections of streptozotocin established a type 2 diabetes mellitus rat model. Model rats were randomly divided into a laser acupoint irradiation group, rosiglitazone control group, and placebo group; each group had 10 rats. In addition, 10 normal male rats were selected for the normal control group. The Housanli, Neiting and Yishu acupoints of the rats in the laser acupoint irradiation group were irradiated with a 10 mW semiconductor laser; each point was irradiated for 15 min, once every 2 d over 28 d, for a total of 14 episodes of irradiation. The rosiglitazone group rats were given rosiglitazone (0.2 mg kg-1) intragastrically; the placebo group rats were given 0.9% brine (0.2 mg kg-1) intragastrically, once daily, for four consecutive weeks. The change of fasting blood glucose was determined before and after each treatment. The islet beta-cell apoptosis was determined. The islet beta-cell apoptosis rates of the laser acupoint irradiation group and the rosiglitazone group were significantly lower than the rate of the placebo group. Even though the rate was lower in the laser acupoint irradiation group than in the rosiglitazone group, there was no significant difference between them. It is shown that acupoint irradiation with a semiconductor laser can effectively inhibit islet beta-cell apoptosis in rats with type 2 diabetes.

  9. Drp1 guarding of the mitochondrial network is important for glucose-stimulated insulin secretion in pancreatic beta cells

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, Florian; Schultz, Julia; Waterstradt, Rica; Baltrusch, Simone, E-mail: simone.baltrusch@med.uni-rostock.de

    2016-06-10

    Mitochondria form a tubular network in mammalian cells, and the mitochondrial life cycle is determined by fission, fusion and autophagy. Dynamin-related protein 1 (Drp1) has a pivotal role in these processes because it alone is able to constrict mitochondria. However, the regulation and function of Drp1 have been shown to vary between cell types. Mitochondrial morphology affects mitochondrial metabolism and function. In pancreatic beta cells mitochondrial metabolism is a key component of the glucose-induced cascade of insulin secretion. The goal of the present study was to investigate the action of Drp1 in pancreatic beta cells. For this purpose Drp1 was down-regulated by means of shDrp1 in insulin-secreting INS1 cells and mouse pancreatic islets. In INS1 cells reduced Drp1 expression resulted in diminished expression of proteins regulating mitochondrial fusion, namely mitofusin 1 and 2, and optic atrophy protein 1. Diminished mitochondrial dynamics can therefore be assumed. After down-regulation of Drp1 in INS1 cells and spread mouse islets the initially homogenous mitochondrial network characterised by a moderate level of interconnections shifted towards high heterogeneity with elongated, clustered and looped mitochondria. These morphological changes were found to correlate directly with functional alterations. Mitochondrial membrane potential and ATP generation were significantly reduced in INS1 cells after Drp1down-regulation. Finally, a significant loss of glucose-stimulated insulin secretion was demonstrated in INS1 cells and mouse pancreatic islets. In conclusion, Drp1 expression is important in pancreatic beta cells to maintain the regulation of insulin secretion. -- Highlights: •Down-regulation of Drp1 in INS1 cells reduces mitochondrial fusion protein expression. •Mitochondrial membrane potential in INS1 cells is diminished after Drp1 down-regulation. •Mitochondria become elongated after down-regulation of Drp1 in beta cells. •Down-regulation of

  10. EPConDB: a web resource for gene expression related to pancreatic development, beta-cell function and diabetes.

    Science.gov (United States)

    Mazzarelli, Joan M; Brestelli, John; Gorski, Regina K; Liu, Junmin; Manduchi, Elisabetta; Pinney, Deborah F; Schug, Jonathan; White, Peter; Kaestner, Klaus H; Stoeckert, Christian J

    2007-01-01

    EPConDB (http://www.cbil.upenn.edu/EPConDB) is a public web site that supports research in diabetes, pancreatic development and beta-cell function by providing information about genes expressed in cells of the pancreas. EPConDB displays expression profiles for individual genes and information about transcripts, promoter elements and transcription factor binding sites. Gene expression results are obtained from studies examining tissue expression, pancreatic development and growth, differentiation of insulin-producing cells, islet or beta-cell injury, and genetic models of impaired beta-cell function. The expression datasets are derived using different microarray platforms, including the BCBC PancChips and Affymetrix gene expression arrays. Other datasets include semi-quantitative RT-PCR and MPSS expression studies. For selected microarray studies, lists of differentially expressed genes, derived from PaGE analysis, are displayed on the site. EPConDB provides database queries and tools to examine the relationship between a gene, its transcriptional regulation, protein function and expression in pancreatic tissues.

  11. Nuclear import of glucokinase in pancreatic beta-cells is mediated by a nuclear localization signal and modulated by SUMOylation.

    Science.gov (United States)

    Johansson, Bente Berg; Fjeld, Karianne; Solheim, Marie Holm; Shirakawa, Jun; Zhang, Enming; Keindl, Magdalena; Hu, Jiang; Lindqvist, Andreas; Døskeland, Anne; Mellgren, Gunnar; Flatmark, Torgeir; Njølstad, Pål Rasmus; Kulkarni, Rohit N; Wierup, Nils; Aukrust, Ingvild; Bjørkhaug, Lise

    2017-10-15

    The localization of glucokinase in pancreatic beta-cell nuclei is a controversial issue. Although previous reports suggest such a localization, the mechanism for its import has so far not been identified. Using immunofluorescence, subcellular fractionation and mass spectrometry, we present evidence in support of glucokinase localization in beta-cell nuclei of human and mouse pancreatic sections, as well as in human and mouse isolated islets, and murine MIN6 cells. We have identified a conserved, seven-residue nuclear localization signal ( 30 LKKVMRR 36 ) in the human enzyme. Substituting the residues KK 31,32 and RR 35,36 with AA led to a loss of its nuclear localization in transfected cells. Furthermore, our data indicates that SUMOylation of glucokinase modulates its nuclear import, while high glucose concentrations do not significantly alter the enzyme nuclear/cytosolic ratio. Thus, for the first time, we provide data in support of a nuclear import of glucokinase mediated by a redundant mechanism, involving a nuclear localization signal, and which is modulated by its SUMOylation. These findings add new knowledge to the functional role of glucokinase in the pancreatic beta-cell. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Design and optimization of beta-cell temperature sensor based on 63Ni–Si

    International Nuclear Information System (INIS)

    Ghasemi Nejad, Gholam Reza; Rahmani, Faezeh; Abaeiani, Gholam Reza

    2014-01-01

    A theoretical study of the use of a beta-cell as a temperature sensor using MCNP4C Monte Carlo code is presented in this paper. Nickel-63 and silicon were selected as the beta source and semiconductor material, respectively. The maximum open-circuit voltage (V OC ) is equal to 0.445 V with doping concentrations of N A =4×10 18 #/cm 3 and N D =8×10 19 #/cm 3 in the base and the emitter region, respectively, which, depending on the source activity, enables measurement in a wide range of temperature. The effects of the activity and its change over time on V OC were also studied. The results demonstrated that V OC exhibited smaller changes for higher activities. The temperature sensitivity of this sensor ranges from −2.42 mV/K to −3.41 mV/K for source activities from 100 mCi to 0.001 mCi, respectively, so the optimal activity can be determined according to the desired temperature range and sensitivity. - Highlights: • A silicon p–n junction using 63 Ni is used as a temperature sensor. • The rate of electron–hole generation in silicon was simulated using Monte Carlo MCNP4c code. • The effects of the structural properties of the semiconductor, such as doping concentration and the thickness of the emitter, on the sensitivity and temperature range were studied. • The source thickness and the effect of the activity and its change over time on V OC were investigated at various temperatures

  13. Relationship Between Beta Cell Dysfunction and Severity of Disease Among Critically Ill Children: A STROBE-Compliant Prospective Observational Study.

    Science.gov (United States)

    Liu, Ping-Ping; Lu, Xiu-Lan; Xiao, Zheng-Hui; Qiu, Jun; Zhu, Yi-Min

    2016-05-01

    Although beta cell dysfunction has been proved to predict prognosis among humans and animals, its prediction on severity of disease remains unclear among children. The present study was aimed to examine the relationship between beta cell dysfunction and severity of disease among critically ill children.This prospective study included 1146 critically ill children, who were admitted to Pediatric Intensive Care Unit (PICU) of Hunan Children's Hospital from November 2011 to August 2013. Information on characteristics, laboratory tests, and prognostic outcomes was collected. Homeostasis model assessment (HOMA)-β, evaluating beta cell function, was used to divide all participants into 4 groups: HOMA-β = 100% (group I, n = 339), 80% ≤ HOMA-β multiple organ dysfunction syndrome (MODS), mechanical ventilation (MV) and mortality. Logistic regression analysis was used to evaluate the risk of developing poor outcomes among patients in different HOMA-β groups, with group I as the reference group.Among 1146 children, incidence of HOMA-β decrement of HOMA-β (P < 0.01). C-reactive protein and procalcitonin levels, rather than white blood cell, were significantly different among 4 groups (P < 0.01). In addition, the worst SOFA score and the worst PRISMIII score increased with declined HOMA-β. For example, the worst SOFA score in group I, II, III, and IV was 1.55 ± 1.85, 1.71 ± 1.93, 1.92 ± 1.63, and 2.18 ± 1.77, respectively. Furthermore, patients with declined HOMA-β had higher risk of developing septic shock, MODS, MV, and mortality, even after adjusting age, gender, myocardial injury, and lung injury. For instance, compared with group I, the multivariate-adjusted odds ratio (95% confidence interval) for developing septic shock was 2.17 (0.59, 8.02), 2.94 (2.18, 6.46), and 2.76 (1.18, 6.46) among patients in group II, III, and IV, respectively.Beta cell dysfunction reflected the severity of disease among critically ill children

  14. **-Postprandial pancreatic ["1"1C]methionine uptake after pancreaticoduodenectomy mirrors basal beta cell function and insulin release

    International Nuclear Information System (INIS)

    Steiner, Emanuel; Kazianka, Lukas; Breuer, Robert; Miholic, Johannes; Hacker, Marcus; Wadsak, Wolfgang; Mitterhauser, Markus; Stimpfl, Thomas; Reiter, Birgit; Karanikas, Georgios

    2017-01-01

    [S-methyl-"1"1C]-L-methionine (["1"1C]MET) uptake in the pancreas might be a central indicator of beta cell function. Since gastric emptying was recently shown to influence glycemic control in subjects after pancreaticoduodenectomy (PD, the surgical treatment of neoplasms of the pancreas head), we looked for imaginable relationships between gastric emptying, pre- and postprandial insulin concentrations, and ["1"1C]MET uptake. Nineteen tumor-free survivors after PD (age mean ± SD: 61 ± 8.7 yrs.; 10 male, 9 female) and 10 healthy controls (age: 27 ± 8.7 yrs.; 7 male, 3 female) were given a mixed test meal. One gram of paracetamol was ingested with the meal to evaluate the speed of gastric emptying. Insulin, glucose, and paracetamol plasma concentrations were measured before and over 180 minutes after ingestion. Beta cell function was calculated from fasting glucose and insulin plasma concentrations. Simultaneously, 800 MBq of ["1"1C]MET were administered and the activity (maximum tissue standardized uptake values [SUVmax]) over the pancreas was measured at 15, 30, and 60 minutes after injection. Total integrated SUVmax (area under the curve [AUC]) and incremental SUVmax were calculated. The uptake of ["1"1C]MET in the pancreas was significantly higher (p < 0.0001) in controls compared to the PD group. Gastric emptying was significantly slower in controls compared to pancreatectomy subjects (p < 0.0001). Paracetamol AUC_3_0 correlated with the SUVmax increment between 15 and 30 minutes (R"2 = 0.27, p = 0.0263), suggesting a relationship between gastric emptying and the uptake of ["1"1C]MET. Total integrated SUVmax correlated with insulin AUC_6_0 (R"2 = 0.66,p < 0.0001) in patients after PD. Multivariate regression analysis revealed insulin AUC_6_0 and beta cell function, calculated from the fasting insulin to glucose ratio, as independent predictors of "1"1C-methionine uptake, i.e. total integrated SUVmax, in patients after PD (R"2 = 0.78, p < 0.0001). Postprandial

  15. **-Postprandial pancreatic [{sup 11}C]methionine uptake after pancreaticoduodenectomy mirrors basal beta cell function and insulin release

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, Emanuel; Kazianka, Lukas; Breuer, Robert; Miholic, Johannes [Medical University of Vienna, Department of Surgery, Vienna (Austria); Hacker, Marcus; Wadsak, Wolfgang; Mitterhauser, Markus [Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Division of Nuclear Medicine, Vienna (Austria); Stimpfl, Thomas; Reiter, Birgit [Medical University of Vienna, Clinical Institute of Laboratory Medicine, Forensic Toxicology, Vienna (Austria); Karanikas, Georgios [Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Division of Nuclear Medicine, Divisional Head PET-PET/CT (Nuclear Medicine), Vienna (Austria)

    2017-03-15

    [S-methyl-{sup 11}C]-L-methionine ([{sup 11}C]MET) uptake in the pancreas might be a central indicator of beta cell function. Since gastric emptying was recently shown to influence glycemic control in subjects after pancreaticoduodenectomy (PD, the surgical treatment of neoplasms of the pancreas head), we looked for imaginable relationships between gastric emptying, pre- and postprandial insulin concentrations, and [{sup 11}C]MET uptake. Nineteen tumor-free survivors after PD (age mean ± SD: 61 ± 8.7 yrs.; 10 male, 9 female) and 10 healthy controls (age: 27 ± 8.7 yrs.; 7 male, 3 female) were given a mixed test meal. One gram of paracetamol was ingested with the meal to evaluate the speed of gastric emptying. Insulin, glucose, and paracetamol plasma concentrations were measured before and over 180 minutes after ingestion. Beta cell function was calculated from fasting glucose and insulin plasma concentrations. Simultaneously, 800 MBq of [{sup 11}C]MET were administered and the activity (maximum tissue standardized uptake values [SUVmax]) over the pancreas was measured at 15, 30, and 60 minutes after injection. Total integrated SUVmax (area under the curve [AUC]) and incremental SUVmax were calculated. The uptake of [{sup 11}C]MET in the pancreas was significantly higher (p < 0.0001) in controls compared to the PD group. Gastric emptying was significantly slower in controls compared to pancreatectomy subjects (p < 0.0001). Paracetamol AUC{sub 30} correlated with the SUVmax increment between 15 and 30 minutes (R{sup 2} = 0.27, p = 0.0263), suggesting a relationship between gastric emptying and the uptake of [{sup 11}C]MET. Total integrated SUVmax correlated with insulin AUC{sub 60} (R{sup 2} = 0.66,p < 0.0001) in patients after PD. Multivariate regression analysis revealed insulin AUC{sub 60} and beta cell function, calculated from the fasting insulin to glucose ratio, as independent predictors of {sup 11}C-methionine uptake, i.e. total integrated SUVmax, in

  16. Minor long-term changes in weight have beneficial effects on insulin sensitivity and beta-cell function in obese subjects

    DEFF Research Database (Denmark)

    Rosenfalck, A M; Hendel, Helle Westergren; Rasmussen, M H

    2002-01-01

    To evaluate the long-term effect of changes in body composition induced by weight loss on insulin sensitivity (SI), non-insulin mediated glucose disposal, glucose effectiveness (SG)and beta-cell function.......To evaluate the long-term effect of changes in body composition induced by weight loss on insulin sensitivity (SI), non-insulin mediated glucose disposal, glucose effectiveness (SG)and beta-cell function....

  17. [Associations of insulin resistance and pancreatic beta-cell function with plasma glucose level in type 2 diabetes].

    Science.gov (United States)

    Nian, Xiaoping; Sun, Gaisheng; Dou, Chunmei; Hou, Hongbo; Fan, Xiuping; Yu, Hongmei; Ma, Ling; He, Bingxian

    2002-06-10

    To investigate the influence of insulin resistance and pancreatic beta-cell function on plasma glucose level in type 2 diabetes so as to provide theoretical basis for reasonable selection of hypoglycemic agents. The plasma non-specific insulin (NSINS), true insulin (TI) and glucose in eight-one type 2 diabetics, 38 males and 43 females, with a mean age of 53 years, were examined 0, 30, 60 and 120 minutes after they had 75 grams of instant noodles. The patients were divided into two groups according to their fasting plasma glucose (FPG): group A (FPG = 8.89 mmol/L). The insulin resistance was evaluated by HOMA-IR, the beta-cell function was evaluated by HOMA-beta formula and the formula deltaI(30)/deltaG(30) = (deltaI(30)-deltaI(0))/(deltaG(30)-deltaG(0)). The insulin area under curve (INSAUC) was evaluated by the formula INSAUC=FINS/2+INS(30)+INS(60)+INS(120)/2. The mean FPG was 6.23 mmol/L in group A and 12.6 mmol/L in group B. PG2H was 11.7 mmol/L in group A and 19.2 mmol/L in group B. The TI levels in group B at 0, 30, 60, 120 min during standard meal test were significantly higher than those in group A: 6.15 +/- 1.06 vs 4.77 +/- 1.06, 9.76 +/- 1.1 vs 5.88 +/- 1.1,14.68 +/- 1.11 vs 6.87 +/- 1.1 and 17.13 +/- 1.12 vs 8.0 +/- 1.1 microU/dl (all P< 0.01). The NSINS showed the same trend. The insulin resistance in group B was 1.5 times that in group A. With the insulin resistance adjusted, the beta cell function in group A was 5 to 6 times that in group B. The INSAUC in group A was 1.66 times larger than that in group B, especially the INSAUC for true insulin (2 times larger). The contribution of insulin resistance and beta cell function to PG2H was half by half in group A and 1:8 in group B. beta cell function calculated by insulin (Homa-beta) explained 41% of the plasma glucose changes in group A and 54% of the plasma glucose changes in group B. The contribution of insulin deficiency to plasma glocose was 3.3.times that of insulin resistance in group A and was 9

  18. Increased secretion of insulin and proliferation of islet {beta}-cells in rats with mesenteric lymph duct ligation

    Energy Technology Data Exchange (ETDEWEB)

    Nagino, Ko; Yokozawa, Junji; Sasaki, Yu; Matsuda, Akiko; Takeda, Hiroaki [Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585 (Japan); Kawata, Sumio, E-mail: Sumio_Kawata@pref.hyogo.lg.jp [Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585 (Japan); Hyogo Prefectural Nishinomiya Hospital, 13-9 Rokutanji-cho, Nishinomiya 662-0918 (Japan)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Insulin secretion was increased during the OGTT or IVGTT in mesenteric lymph duct-ligated rats. Black-Right-Pointing-Pointer Proliferation of islet {beta}-cells was upregulated in lymph duct-ligated rats. Black-Right-Pointing-Pointer Mesenteric lymph duct flow has a role in glucose metabolism. -- Abstract: Background and aims: It has been suggested that intestinal lymph flow plays an important role in insulin secretion and glucose metabolism after meals. In this study, we investigated the influence of ligation of the mesenteric lymph duct on glucose metabolism and islet {beta}-cells in rats. Methods: Male Sprague-Dawley rats (10 weeks old) were divided into two groups: one underwent ligation of the mesenteric lymph duct above the cistern (ligation group), and the other underwent a sham operation (sham group). After 1 and 2 weeks, fasting plasma concentrations of glucose, insulin, triglyceride, glucose-dependent insulinotropic polypeptide (GIP), and the active form of glucagon-like peptide-1 (GLP-1) were measured. At 2 weeks after the operation, the oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (IVGTT) were performed. After the rats had been sacrificed, the insulin content of the pancreas was measured and the proliferation of {beta}-cells was assessed immunohistochemically using antibodies against insulin and Ki-67. Results: During the OGTT, the ligation group showed a significant decrease in the plasma glucose concentration at 120 min (p < 0.05) and a significant increase in the plasma insulin concentration by more than 2-fold at 15 min (p < 0.01). On the other hand, the plasma GIP concentration was significantly decreased at 60 min (p < 0.01) in the ligated group, while the active form of GLP-1 showed a significantly higher level at 90 min (1.7-fold; p < 0.05) and 120 min (2.5-fold; p < 0.01). During the IVGTT, the plasma insulin concentration in the ligation group was significantly higher at 2

  19. Gallic acid attenuates high-fat diet fed-streptozotocin-induced insulin resistance via partial agonism of PPARγ in experimental type 2 diabetic rats and enhances glucose uptake through translocation and activation of GLUT4 in PI3K/p-Akt signaling pathway.

    Science.gov (United States)

    Gandhi, Gopalsamy Rajiv; Jothi, Gnanasekaran; Antony, Poovathumkal James; Balakrishna, Kedike; Paulraj, Michael Gabriel; Ignacimuthu, Savarimuthu; Stalin, Antony; Al-Dhabi, Naif Abdullah

    2014-12-15

    In this study, the therapeutic efficacy of gallic acid from Cyamopsis tetragonoloba (L.) Taub. (Fabaceae) beans was examined against high-fat diet fed-streptozotocin-induced experimental type 2 diabetic rats. Molecular-dockings were done to determine the putative binding modes of gallic acid into the active sites of key insulin-signaling markers. Gallic acid (20 mg/kg) given to high-fat diet fed-streptozotocin-induced rats lowered body weight gain, fasting blood glucose and plasma insulin in diabetic rats. It further restored the alterations of biochemical parameters to near normal levels in diabetic treated rats along with cytoprotective action on pancreatic β-cell. Histology of liver and adipose tissues supported the biochemical findings. Gallic acid significantly enhanced the level of peroxisome proliferator-activated receptor γ (PPARγ) expression in the adipose tissue of treated rat compared to untreated diabetic rat; it also slightly activated PPARγ expressions in the liver and skeletal muscle. Consequently, it improved insulin-dependent glucose transport in adipose tissue through translocation and activation of glucose transporter protein 4 (GLUT4) in phosphatidylinositol 3-kinase (PI3K)/phosphorylated protein kinase B (p-Akt) dependent pathway. Gallic acid docked with PPARγ; it exhibited promising interactions with the GLUT4, glucose transporter protein 1 (GLUT1), PI3K and p-Akt. These findings provided evidence to show that gallic acid could improve adipose tissue insulin sensitivity, modulate adipogenesis, increase adipose glucose uptake and protect β-cells from impairment. Hence it can be used in the management of obesity-associated type 2 diabetes mellitus. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Reactive hypoglycemia in lean young women with PCOS and correlations with insulin sensitivity and with beta cell function.

    Science.gov (United States)

    Altuntas, Yuksel; Bilir, Muammer; Ucak, Sema; Gundogdu, Sadi

    2005-04-01

    Reactive hypoglycemia (RH), which is a postprandial hypoglycemic state, occurs within 2-5 h after food intake. It is classified as idiopathic, alimentary, or diabetic reactive hypoglycemia. We studied the incidence of reactive hypoglycemia and looked for any correlations between it and the presence of insulin sensitivity and/or beta cell function in young lean polycystic ovary syndrome (PCOS) patients. This study was designed as a cross-sectional study in 64 lean young women with PCOS (BMI lean young women with PCOS. DHEA-S and PRL levels were found to be lower in subjects with RH (P 0.05, respectively). Beta cell function indices such as the insulinogenic index (at 120 min), CIR (at 120 min) and HOMA beta cell index were found to be insignificantly higher in the RH group than the nonreactive hypoglycemia (NRH) group. The 4 h glucose level, but not the 3 h glucose level, was significantly correlated with insulin resistance indices, such as fasting insulin level, HOMA-IR, Quicky index, and FIRI in the RH group. Significantly decreased DHEA-S levels were an interesting finding. In conclusion, there is an urgent need to investigate RH in lean young women with PCOS. Our results indicate that more definite insulin resistance occurs in subjects with RH in the fourth hour of the OGTT than those with RH in the third hour. In addition, RH in the fourth hour together with a low DHEA-S level may be predictive of future diabetes in young women with PCOS even when they are not obese.

  1. Maternal obesity accelerates fetal pancreatic beta-cell but not alpha-cell development in sheep: prenatal consequences.

    Science.gov (United States)

    Ford, Stephen P; Zhang, Liren; Zhu, Meijun; Miller, Myrna M; Smith, Derek T; Hess, Bret W; Moss, Gary E; Nathanielsz, Peter W; Nijland, Mark J

    2009-09-01

    Maternal obesity affects offspring weight, body composition, and organ function, increasing diabetes and metabolic syndrome risk. We determined effects of maternal obesity and a high-energy diet on fetal pancreatic development. Sixty days prior to breeding, ewes were assigned to control [100% of National Research Council (NRC) recommendations] or obesogenic (OB; 150% NRC) diets. At 75 days gestation, OB ewes exhibited elevated insulin-to-glucose ratios at rest and during a glucose tolerance test, demonstrating insulin resistance compared with control ewes. In fetal studies, ewes ate their respective diets from 60 days before to 75 days after conception when animals were euthanized under general anesthesia. OB and control ewes increased in body weight by approximately 43% and approximately 6%, respectively, from diet initiation until necropsy. Although all organs were heavier in fetuses from OB ewes, only pancreatic weight increased as a percentage of fetal weight. Blood glucose, insulin, and cortisol were elevated in OB ewes and fetuses on day 75. Insulin-positive cells per unit pancreatic area were 50% greater in fetuses from OB ewes as a result of increased beta-cell mitoses rather than decreased programmed cell death. Lambs of OB ewes were born earlier but weighed the same as control lambs; however, their crown-to-rump length was reduced, and their fat mass was increased. We conclude that increased systemic insulin in fetuses from OB ewes results from increased glucose exposure and/or cortisol-induced accelerated fetal beta-