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Sample records for apigenin inhibits hgf-promoted

  1. Apigenin inhibits HGF-promoted invasive growth and metastasis involving blocking PI3K/Akt pathway and β4 integrin function in MDA-MB-231 breast cancer cells

    International Nuclear Information System (INIS)

    Lee, W.-J.; Chen, W.-K.; Wang, C.-J.; Lin, W.-L.; Tseng, T.-H.

    2008-01-01

    Hepatocyte growth factor (HGF) and its receptor, Met, known to control invasive growth program have recently been shown to play crucial roles in the survival of breast cancer patients. The diet-derived flavonoids have been reported to possess anti-invasion properties; however, knowledge on the pharmacological and molecular mechanisms in suppressing HGF/Met-mediated tumor invasion and metastasis is poorly understood. In our preliminary study, we use HGF as an invasive inducer to investigate the effect of flavonoids including apigenin, naringenin, genistein and kaempferol on HGF-dependent invasive growth of MDA-MB-231 human breast cancer cells. Results show that apigenin presents the most potent anti-migration and anti-invasion properties by Boyden chamber assay. Furthermore, apigenin represses the HGF-induced cell motility and scattering and inhibits the HGF-promoted cell migration and invasion in a dose-dependent manner. The effect of apigenin on HGF-induced signaling activation involving invasive growth was evaluated by immunoblotting analysis, it shows that apigenin blocks the HGF-induced Akt phosphorylation but not Met, ERK, and JNK phosphorylation. In addition to MDA-MB-231 cells, apigenin exhibits inhibitory effect on HGF-induced Akt phosphorylation in hepatoma SK-Hep1 cells and lung carcinoma A549 cells. By indirect immunofluorescence microscopy assay, apigenin inhibits the HGF-induced clustering of β4 integrin at actin-rich adhesive site and lamellipodia through PI3K-dependent manner. Treatment of apigenin inhibited HGF-stimulated integrin β4 function including cell-matrix adhesion and cell-endothelial cells adhesion in MDA-MB-231 cells. By Akt-siRNA transfection analysis, it confirmed that apigenin inhibited HGF-promoted invasive growth involving blocking PI3K/Akt pathway. Finally, we evaluated the effect of apigenin on HGF-promoted metastasis by lung colonization of tumor cells in nude mice and organ metastasis of tumor cells in chick embryo. By

  2. Apigenin inhibits proliferation and migratory properties of Barrett's ...

    African Journals Online (AJOL)

    dependent fashion, with an IC50 of 75 µM, after 72 h of incubation, and also induced apoptosis, with modulation of pro- and anti-apoptotic genes. Furthermore, apigenin inhibited the motility of OE33 by targeting PI3K/Akt/mTOR signaling. Conclusion: Apigenin effectively inhibits the oncogenicity of OE33 cells by targeting ...

  3. Inhibition of Epstein-Barr virus reactivation by the flavonoid apigenin.

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    Wu, Chung-Chun; Fang, Chih-Yeu; Cheng, Yu-Jhen; Hsu, Hui-Yu; Chou, Sheng-Ping; Huang, Sheng-Yen; Tsai, Ching-Hwa; Chen, Jen-Yang

    2017-01-05

    Lytic reactivation of EBV has been reported to play an important role in human diseases, including NPC carcinogenesis. Inhibition of EBV reactivation is considered to be of great benefit in the treatment of virus-associated diseases. For this purpose, we screened for inhibitory compounds and found that apigenin, a flavonoid, seemed to have the ability to inhibit EBV reactivation. We performed western blotting, immunofluorescence and luciferase analyses to determine whether apigenin has anti-EBV activity. Apigenin inhibited expression of the EBV lytic proteins, Zta, Rta, EAD and DNase in epithelial and B cells. It also reduced the number of EBV-reactivating cells detectable by immunofluorescence analysis. In addition, apigenin has been found to reduce dramatically the production of EBV virions. Luciferase reporter analysis was performed to determine the mechanism by which apigenin inhibits EBV reactivation: apigenin suppressed the activity of the immediate-early (IE) gene Zta and Rta promoters, suggesting it can block initiation of the EBV lytic cycle. Taken together, apigenin inhibits EBV reactivation by suppressing the promoter activities of two viral IE genes, suggesting apigenin is a potential dietary compound for prevention of EBV reactivation.

  4. Apigenin Restricts FMDV Infection and Inhibits Viral IRES Driven Translational Activity

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    Suhong Qian

    2015-03-01

    Full Text Available Foot-and-mouth disease (FMD is a highly contagious disease of domestic and wild ruminants that is caused by FMD virus (FMDV. FMD outbreaks have occurred in livestock-containing regions worldwide. Apigenin, which is a flavonoid naturally existing in plant, possesses various pharmacological effects, including anti-inflammatory, anticancer, antioxidant and antiviral activities. Results show that apigenin can inhibit FMDV-mediated cytopathogenic effect and FMDV replication in vitro. Further studies demonstrate the following: (i apigenin inhibits FMDV infection at the viral post-entry stage; (ii apigenin does not exhibit direct extracellular virucidal activity; and (iii apigenin interferes with the translational activity of FMDV driven by internal ribosome entry site. Studies on applying apigein in vivo are required for drug development and further identification of potential drug targets against FDMV infection.

  5. Insight into the novel inhibition mechanism of apigenin to Pneumolysin by molecular modeling

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    Niu, Xiaodi; Yang, Yanan; Song, Meng; Wang, Guizhen; Sun, Lin; Gao, Yawen; Wang, Hongsu

    2017-11-01

    In this study, the mechanism of apigenin inhibition was explored using molecular modelling, binding energy calculation, and mutagenesis assays. Energy decomposition analysis indicated that apigenin binds in the gap between domains 3 and 4 of PLY. Using principal component analysis, we found that binding of apigenin to PLY weakens the motion of domains 3 and 4. Consequently, these domains cannot complete the transition from monomer to oligomer, thereby blocking oligomerisation of PLY and counteracting its haemolytic activity. This inhibitory mechanism was confirmed by haemolysis assays, and these findings will promote the future development of an antimicrobial agent.

  6. Apigenin inhibits proliferation and migratory properties of Barrett's ...

    African Journals Online (AJOL)

    Methods: Proliferation index of OE33 in the absence and presence of apigenin was determined by methyl-thiazolyl-tetrazolium (MTT) assay and apoptosis was determined by enzyme-linked immunosorbent assay (ELISA) method. Boyden Chamber's assay was applied to determine the migration and invasion of control and ...

  7. Apigenin inhibits release of inflammatory mediators by blocking the NF-κB activation pathways in the HMC-1 cells.

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    Kang, Ok-Hwa; Lee, John-Hwa; Kwon, Dong-Yeul

    2011-09-01

    Apigenin is a plant flavonoid and a pharmacologically active agent that has been isolated from several plant species. However, the molecular mechanism of apigenin-mediated immune modulation has not been fully understood. One of the possible mechanisms of its protective effects is the down-regulation of inflammatory responses. In this study, we used cells from the human mast cell line (HMC-1) to investigate this effect. Apigenin significantly inhibits the inductive effect of phorbol 12-myristate 13-acetate (PMA) plus A23187 on the production of inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-8, IL-6, and granulocyte-macrophage colony-stimulating factor (GM-CSF). Moreover, apigenin attenuated the cyclooxygenase (COX)-2 expression and intracellular Ca(2+) level. In activated HMC-1 cells, apigenin inhibited the PMA plus A23187-induced activation of nuclear factor (NF)-κB, IκB degradation, and luciferase activity. Furthermore, apigenin suppressed the expression of TNF-α, IL-8, IL-6, GM-CSF, and COX-2 by decreasing the intracellular Ca(2+) level and inhibiting NF-κB activation. These results indicate that apigenin has a potential regulatory effect on inflammatory reactions that are mediated by mast cells.

  8. Inhibiting GLUT-1 expression and PI3K/Akt signaling using apigenin improves the radiosensitivity of laryngeal carcinoma in vivo.

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    Bao, Yang-Yang; Zhou, Shui-Hong; Lu, Zhong-Jie; Fan, Jun; Huang, Ya-Ping

    2015-10-01

    Hypoxia is an important factor in radioresistance of laryngeal carcinoma. Glucose transporter-1 (GLUT-1) is an important hypoxic marker in malignant tumors, including laryngeal carcinoma. Apigenin is a natural phytoestrogen flavonoid that has potential anticancer effects. Various studies have reported that the effects of apigenin on lowering GLUT-1 expression were involved in downregulation of the PI3K/Akt pathway. Thus, apigenin may improve the radiosensitivity of laryngeal carcinoma by suppressing the expression of GLUT-1 via the PI3K/Akt pathway. The effect of GLUT-1 and PI3K/Akt pathway-related factor expressions by apigenin or antisense oligonucleotides (AS-ODNs) on the radiosensitivity of laryngeal carcinoma in vivo was assessed. The xenograft volume, xenograft weight and apoptosis detection were performed to determine radiosensitivity. The results showed that apigenin or apigenin plus GLUT-1 AS-ODNs improved the radiosensitivity of xenografts. Apigenin or apigenin plus GLUT-1 reduced the expression of GLUT-1, Akt, and PI3K mRNA after X-ray radiation. We found similar results at the protein level. The results suggest that the effects of apigenin on inhibiting xenograft growth and enhancing xenograft radiosensitivity may be associated with suppressing the expression of GLUT-1 via the PI3K/Akt pathway. In addition, apigenin may enhance the effects of GLUT-1 AS-ODNs via the same mechanism.

  9. The flavones apigenin and luteolin induce FOXO1 translocation but inhibit gluconeogenic and lipogenic gene expression in human cells.

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    Christiane Bumke-Vogt

    Full Text Available The flavones apigenin (4',5,7,-trihydroxyflavone and luteolin (3',4',5,7,-tetrahydroxyflavone are plant secondary metabolites with antioxidant, antiinflammatory, and anticancer activities. We evaluated their impact on cell signaling pathways related to insulin-resistance and type 2 diabetes. Apigenin and luteolin were identified in our U-2 OS (human osteosarcoma cell screening assay for micronutrients triggering rapid intracellular translocation of the forkhead box transcription factor O1 (FOXO1, an important mediator of insulin signal transduction. Insulin reversed the translocation of FOXO1 as shown by live cell imaging. The impact on the expression of target genes was evaluated in HepG2 (human hepatoma cells. The mRNA-expression of the gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK and glucose-6-phosphatase (G6Pc, the lipogenic enzymes fatty-acid synthase (FASN and acetyl-CoA-carboxylase (ACC were down-regulated by both flavones with smaller effective dosages of apigenin than for luteolin. PKB/AKT-, PRAS40-, p70S6K-, and S6-phosphorylation was reduced by apigenin and luteolin but not that of the insulin-like growth factor receptor IGF-1R by apigenin indicating a direct inhibition of the PKB/AKT-signaling pathway distal to the IGF-1 receptor. N-acetyl-L-cysteine did not prevent FOXO1 nuclear translocation induced by apigenin and luteolin, suggesting that these flavones do not act via oxidative stress. The roles of FOXO1, FOXO3a, AKT, sirtuin1 (SIRT1, and nuclear factor (erythroid-derived2-like2 (NRF2, investigated by siRNA knockdown, showed differential patterns of signal pathways involved and a role of NRF2 in the inhibition of gluconeogenic enzyme expression. We conclude that these flavones show an antidiabetic potential due to reduction of gluconeogenic and lipogenic capacity despite inhibition of the PKB/AKT pathway which justifies detailed investigation in vivo.

  10. Apigenin Inhibits Human SW620 Cell Growth by Targeting Polyamine Catabolism

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    Jing Wang

    2017-01-01

    Full Text Available Apigenin is a nonmutagenic flavonoid that has antitumor properties. Polyamines are ubiquitous cellular polycations, which play an important role in the proliferation and differentiation of cancer cells. Highly regulated pathways control the biosynthesis and degradation of polyamines. Ornithine decarboxylase (ODC is the rate-limiting enzyme in the metabolism, and spermidine/spermine-N1-Acetyl transferase (SSAT is the rate-limiting enzyme in the catabolism of polyamines. In the current study, the effect of increasing concentrations of apigenin on polyamine levels, ODC and SSAT protein expression, mRNA expression, cell proliferation and apoptosis, and the production of reactive oxygen species (ROS was investigated in SW620 colon cancer cells. The results showed that apigenin significantly reduced cell proliferation, decreased the levels of spermidine and spermine, and increased previously downregulated putrescine contents. Apigenin also enhanced SSAT protein and mRNA levels and the production of reactive oxygen species in SW620 cells, though it had no significant effect on the levels of ODC protein or mRNA. Apigenin appears to decrease the proliferation rate of human SW620 cells by facilitating SSAT expression to induce polyamine catabolism and increasing ROS levels to induce cell apoptosis.

  11. Dietary apigenin potentiates the inhibitory effect of interferon-α on cancer cell viability through inhibition of 26S proteasome-mediated interferon receptor degradation

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    Sheng Li

    2016-06-01

    Full Text Available Background: Type I interferons (IFN-α/β have broad and potent immunoregulatory and antiproliferative activities. However, it is still known whether the dietary flavonoids exhibit their antiviral and anticancer properties by modulating the function of type I IFNs. Objective: This study aimed at determining the role of apigenin, a dietary plant flavonoid abundant in common fruits and vegetables, on the type I IFN-mediated inhibition of cancer cell viability. Design: Inhibitory effect of apigenin on human 26S proteasome, a known negative regulator of type I IFN signaling, was evaluated in vitro. Molecular docking was conducted to know the interaction between apigenin and subunits of 26S proteasome. Effects of apigenin on JAK/STAT pathway, 26S proteasome-mediated interferon receptor stability, and cancer cells viability were also investigated. Results: Apigenin was identified to be a potent inhibitor of human 26S proteasome in a cell-based assay. Apigenin inhibited the chymotrypsin-like, caspase-like, and trypsin-like activities of the human 26S proteasome and increased the ubiquitination of endogenous proteins in cells. Results from computational modeling of the potential interactions of apigenin with the chymotrypsin site (β5 subunit, caspase site (β1 subunit, and trypsin site (β2 subunit of the proteasome were consistent with the observed proteasome inhibitory activity. Apigenin enhanced the phosphorylation of signal transducer and activator of transcription proteins (STAT1 and STAT2 and promoted the endogenous IFN-α-regulated gene expression. Apigenin inhibited the IFN-α-stimulated ubiquitination and degradation of type I interferon receptor 1 (IFNAR1. Apigenin also sensitized the inhibitory effect of IFN-α on viability of cervical carcinoma HeLa cells. Conclusion: These results suggest that apigenin potentiates the inhibitory effect of IFN-α on cancer cell viability by activating JAK/STAT signaling pathway through inhibition of 26S

  12. Apigenin induces caspase-dependent apoptosis by inhibiting signal transducer and activator of transcription 3 signaling in HER2-overexpressing SKBR3 breast cancer cells.

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    Seo, Hye-Sook; Ku, Jin Mo; Choi, Han-Seok; Woo, Jong-Kyu; Jang, Bo-Hyoung; Go, Hoyeon; Shin, Yong Cheol; Ko, Seong-Gyu

    2015-08-01

    Phytoestrogens have been demonstrated to inhibit tumor induction; however, their molecular mechanisms of action have remained elusive. The present study aimed to investigate the effects of a phytoestrogen, apigenin, on proliferation and apoptosis of the human epidermal growth factor receptor 2 (HER2)-expressing breast cancer cell line SKBR3. Proliferation assay, MTT assay, fluorescence-activated cell sorting analysis, western blot analysis, immunocytochemistry, reverse transcription-polymerase chain reaction and ELISA assay were used in the present study. The results of the present study indicated that apigenin inhibited the proliferation of SKBR3 cells in a dose-and time-dependent manner. This inhibition of growth was accompanied by an increase in the sub-G0/G1 apoptotic population. Furthermore, apigenin enhanced the expression levels of cleaved caspase-8 and -3, and induced the cleavage of poly(adenosine diphosphate ribose) polymerase in SKBR3 cells, confirming that apigenin promotes apoptosis via a caspase-dependent pathway. Apigenin additionally reduced the expression of phosphorylated (p)-janus kinase 2 and p-signal transducer and activator of transcription 3 (STAT3), inhibited CoCl2-induced vascular endothelial growth factor (VEGF) secretion and decreased the nuclear localization of STAT3. The STAT3 inhibitor S31-201 decreased the cellular proliferation rate and reduced the expression of p-STAT3 and VEGF. Therefore, these results suggested that apigenin induced apoptosis via the inhibition of STAT3 signaling in SKBR3 cells. In conclusion, the results of the present study indicated that apigenin may be a potentially useful compound for the prevention or treatment of HER2-overexpressing breast cancer.

  13. Apigenin inhibits proliferation and induces apoptosis in human multiple myeloma cells through targeting the trinity of CK2, Cdc37 and Hsp90

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    Xu Yuan-Ji

    2011-08-01

    Full Text Available Abstract Background Multiple myeloma (MM is a B-cell malignancy that is largely incurable and is characterized by the accumulation of malignant plasma cells in the bone marrow. Apigenin, a common flavonoid, has been reported to suppress proliferation in a wide variety of solid tumors and hematological cancers; however its mechanism is not well understood and its effect on MM cells has not been determined. Results In this study, we investigated the effects of apigenin on MM cell lines and on primary MM cells. Cell viability assays demonstrated that apigenin exhibited cytotoxicity against both MM cell lines and primary MM cells but not against normal peripheral blood mononuclear cells. Together, kinase assays, immunoprecipitation and western blot analysis showed that apigenin inhibited CK2 kinase activity, decreased phosphorylation of Cdc37, disassociated the Hsp90/Cdc37/client complex and induced the degradation of multiple kinase clients, including RIP1, Src, Raf-1, Cdk4 and AKT. By depleting these kinases, apigenin suppressed both constitutive and inducible activation of STAT3, ERK, AKT and NF-κB. The treatment also downregulated the expression of the antiapoptotic proteins Mcl-1, Bcl-2, Bcl-xL, XIAP and Survivin, which ultimately induced apoptosis in MM cells. In addition, apigenin had a greater effects in depleting Hsp90 clients when used in combination with the Hsp90 inhibitor geldanamycin and the histone deacetylase inhibitor vorinostat. Conclusions Our results suggest that the primary mechanisms by which apigenin kill MM cells is by targeting the trinity of CK2-Cdc37-Hsp90, and this observation reveals the therapeutic potential of apigenin in treating multiple myeloma.

  14. Apigenin alleviates the symptoms of Staphylococcus aureus pneumonia by inhibiting the production of alpha-hemolysin.

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    Dong, Jing; Qiu, Jiazhang; Wang, Jianfeng; Li, Hongen; Dai, Xiaohan; Zhang, Yu; Wang, Xin; Tan, Wei; Niu, Xiaodi; Deng, Xuming; Zhao, Shuhua

    2013-01-01

    Staphylococcus aureus is a common human pathogenic bacteria that can cause serious infections, including lethal staphylococcal pneumonia. The development of antimicrobial resistance has limited treatment options for this pathogen; consequently, novel antibiotics and strategies are urgently desired to combat these infections. In recent years, virulence factors secreted by pathogenic microorganisms have been developed as targets for drug discovery. Alpha-hemolysin, a pore-forming cytotoxin that is secreted by most S. aureus strains, is essential for the pathogenesis of S. aureus pneumonia. In this study, we report that apigenin, a compound extracted from parsley that has no antimicrobial activity vs. S. aureus in vitro, can remarkably decrease the production of α-hemolysin at low concentrations. When added to the A549 cells and S. aureus co-culture system, apigenin protected A549 cells from α-hemolysin-mediated injury. Furthermore, in vivo tests indicated that apigenin alleviated injury of the lung tissue and decreased cytokine levels in the bronchoalveolar lavage fluid in the mouse model of S. aureus pneumonia. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  15. Apigenin inhibits d-galactosamine/LPS-induced liver injury through upregulation of hepatic Nrf-2 and PPARγ expressions in mice.

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    Zhou, Rui-Jun; Ye, Hua; Wang, Feng; Wang, Jun-Long; Xie, Mei-Lin

    2017-11-04

    Apigenin is a natural flavonoid compound widely distributed in a variety of vegetables, medicinal plants and health foods. This study aimed to examine the protective effect of apigenin against d-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced mouse liver injury and to investigate the potential biochemical mechanisms. The results showed that after oral administration of apigenin 100-200 mg/kg for 7 days, the levels of serum alanine aminotransferase and aspartate aminotransferase were decreased, and the severity of liver injury was alleviated. Importantly, apigenin pretreatment increased the levels of hepatic nuclear factor erythroid 2-related factor 2 (Nrf-2) and peroxisome proliferator-activated receptor γ (PPARγ) protein expressions as well as superoxide dismutase, catalase, glutathione S-transferase and glutathione reductase activities, decreased the levels of hepatic nuclear factor-κB (NF-κB) protein expression and tumor necrosis factor-α. These findings demonstrated that apigenin could prevent the D-GalN/LPS-induced liver injury in mice, and its mechanisms might be associated with the increments of Nrf-2-mediated antioxidative enzymes and modulation of PPARγ/NF-κB-mediated inflammation. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Apigenin-7-diglucuronide protects retinas against bright light-induced photoreceptor degeneration through the inhibition of retinal oxidative stress and inflammation.

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    Bian, Minjuan; Zhang, Yong; Du, Xiaoye; Xu, Jing; Cui, Jingang; Gu, Jiangping; Zhu, Weiliang; Zhang, Teng; Chen, Yu

    2017-05-15

    Vision impairment in retinal degenerative diseases such as age-related macular degeneration is primarily associated with photoreceptor degeneration, in which oxidative stress and inflammatory responses are mechanistically involved as central players. Therapies with photoreceptor protective properties remain to be developed. Apigenin-7-diglucuronide (A7DG), a flavonoid glycoside, is present in an assortment of medicinal plants with anti-inflammatory or ant-oxidant activities. However, the pharmacological significance of A7DG remains unknown in vivo. The current study isolated A7DG from Glechoma longituba (Nakai) Kuprian and investigated the retinal protective effect A7DG in mice characterized by bright light-induced photoreceptor degeneration. The results showed that A7DG treatment led to remarkable photoreceptor protection in bright light-exposed BALB/c mice. Moreover, A7DG treatment alleviated photoreceptor apoptosis, mitigated oxidative stress, suppressed reactive gliosis and microglial activation and attenuated the expression of proinflammatory genes in bright light-exposed retinas. The results demonstrated for the first time remarkable photoreceptor protective activities of A7DG in vivo. Inhibition of bright light-induced retinal oxidative stress and retinal inflammatory responses was associated with the retinal protection conferred by A7DG. The work here warrants further evaluation of A7DG as a pharmacological candidate for the treatment of vision-threatening retinal degenerative disorders. Moreover, given the general implication of oxidative stress and inflammation in the pathogenesis of neurodegeneration, A7DG could be further tested for the treatment of other neurodegenerative disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Downregulation of NEDD9 by apigenin suppresses migration, invasion, and metastasis of colorectal cancer cells

    International Nuclear Information System (INIS)

    Dai, Jin; Van Wie, Peter G.; Fai, Leonard Yenwong; Kim, Donghern; Wang, Lei; Poyil, Pratheeshkumar; Luo, Jia; Zhang, Zhuo

    2016-01-01

    Apigenin is a natural flavonoid which possesses multiple anti-cancer properties such as anti-proliferation, anti-inflammation, and anti-metastasis in many types of cancers including colorectal cancer. Neural precursor cell expressed developmentally downregulated 9 (NEDD9) is a multi-domain scaffolding protein of the Cas family which has been shown to correlate with cancer metastasis and progression. The present study investigates the role of NEDD9 in apigenin-inhibited cell migration, invasion, and metastasis of colorectal adenocarcinoma DLD1 and SW480 cells. The results show that knockdown of NEDD9 inhibited cell migration, invasion, and metastasis and that overexpression of NEDD9 promoted cell migration and invasion of DLD1 cells and SW4890 cells. Apigenin treatment attenuated NEDD9 expression at protein level, resulting in reduced phosphorylations of FAK, Src, and Akt, leading to inhibition on cell migration, invasion, and metastasis of both DLD1 and SW480 cells. The present study has demonstrated that apigenin inhibits cell migration, invasion, and metastasis through NEDD9/Src/Akt cascade in colorectal cancer cells. NEDD9 may function as a biomarker for evaluation of cancer aggressiveness and for selection of therapeutic drugs against cancer progression. - Highlights: • Apigenin inhibits migration, invasion, and metastasis of colorectal cancer cells. • Apigenin downregulates NEDD9. • Apigenin decreases phosphorylations of FAK, Src, and Akt. • Apigenin inhibits cell migration, invasion, and metastasis through NEDD9/Src/Akt.

  18. Apigenin Impacts the Growth of the Gut Microbiota and Alters the Gene Expression of Enterococcus

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    Minqian Wang

    2017-08-01

    Full Text Available Apigenin is a major dietary flavonoid with many bioactivities, widely distributed in plants. Apigenin reaches the colon region intact and interacts there with the human gut microbiota, however there is little research on how apigenin affects the gut bacteria. This study investigated the effect of pure apigenin on human gut bacteria, at both the single strain and community levels. The effect of apigenin on the single gut bacteria strains Bacteroides galacturonicus, Bifidobacterium catenulatum, Lactobacillus rhamnosus GG, and Enterococcus caccae, was examined by measuring their anaerobic growth profiles. The effect of apigenin on a gut microbiota community was studied by culturing a fecal inoculum under in vitro conditions simulating the human ascending colon. 16S rRNA gene sequencing and GC-MS analysis quantified changes in the community structure. Single molecule RNA sequencing was used to reveal the response of Enterococcus caccae to apigenin. Enterococcus caccae was effectively inhibited by apigenin when cultured alone, however, the genus Enterococcus was enhanced when tested in a community setting. Single molecule RNA sequencing found that Enterococcus caccae responded to apigenin by up-regulating genes involved in DNA repair, stress response, cell wall synthesis, and protein folding. Taken together, these results demonstrate that apigenin affects both the growth and gene expression of Enterococcus caccae.

  19. Resveratrol as a Bioenhancer to Improve Anti-Inflammatory Activities of Apigenin

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    Jin-Ah Lee

    2015-11-01

    Full Text Available The aim of this study was to improve the anti-inflammatory activities of apigenin through co-treatment with resveratrol as a bioenhancer of apigenin. RAW 264.7 cells pretreated with hepatic metabolites formed by the co-metabolism of apigenin and resveratrol (ARMs in HepG2 cells were stimulated with lipopolysaccharide (LPS. ARMs prominently inhibited (p < 0.05 the production of nitric oxide (NO, prostaglandin E2 (PGE2, interleukin (IL-1β, IL-6 and TNF-α. Otherwise no such activity was observed by hepatic metabolites of apigenin alone (AMs. ARMs also effectively suppressed protein expressions of inducible nitric oxide synthase (iNOS and cyclooxygenase-2 (COX-2. Co-administration of apigenin (50 mg/kg and resveratrol (25 mg/kg also showed a significant reduction of carrageenan-induced paw edema in mice (61.20% to 23.81%. Co-administration of apigenin and resveratrol led to a 2.39 fold increase in plasma apigenin levels compared to administration of apigenin alone, suggesting that co-administration of resveratrol could increase bioavailability of apigenin. When the action of resveratrol on the main apigenin metabolizing enzymes, UDP-glucuronosyltransferases (UGTs, was investigated, resveratrol mainly inhibited the formation of apigenin glucuronides by UGT1A9 in a non-competitive manner with a Ki value of 7.782 μM. These results suggested that resveratrol helps apigenin to bypass hepatic metabolism and maintain apigenin’s anti-inflammatory activities in the body.

  20. Neuroprotective, Anti-Amyloidogenic and Neurotrophic Effects of Apigenin in an Alzheimer’s Disease Mouse Model

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    Lu Zhang

    2013-08-01

    Full Text Available Alzheimer’s disease (AD is a neurodegenerative disorder characterized by extracellular senile plaques and intracellular neurofibrillary tangles in the brain. Amyloid-β peptides (Aβ are considered to play a critical role in the onset and progression of AD. Apigenin (4',5,7-trihydroxyflavone is a pharmacologically active agent. Even though some evidence suggests that it has potential neuroprotective effects, no preexisting study has reported any therapeutic effects of apigenin in AD models. In the present study, we examined the effects of apigenin on cognitive function in APP/PS1 double transgenic AD mice and explored its mechanism(s of action. Three-month oral treatment with apigenin rescued learning deficits and relieved memory retention in APP/PS1 mice. Apigenin also showed effects affecting APP processing and preventing Aβ burden due to the down-regulation of BACE1 and β-CTF levels, the relief of Aβ deposition, and the decrease of insoluble Aβ levels. Moreover, apigenin exhibited superoxide anion scavenging effects and improved antioxidative enzyme activity of superoxide dismutase and glutathione peroxidase. In addition, apigenin restored neurotrophic ERK/CREB/BDNF pathway in the cerebral cortex. In conclusion, apigenin may ameliorate AD-associated learning and memory impairment through relieving Aβ burden, suppressing amyloidogenic process, inhibiting oxidative stress, and restoring ERK/CREB/BDNF pathway. Therefore, apigenin appears to represent an alternative medication for the prevention and/or therapy of AD.

  1. Antibacterial Attributes of Apigenin, Isolated from Portulaca oleracea L.

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    Hanumantappa B. Nayaka

    2014-01-01

    Full Text Available The flavonoid apigenin was isolated from aerial part of P. oleracea L. The dried sample of plant was powdered and subjected to soxhlet extractor by adding 80 mL of ethanol : water (70 : 30. The extract was centrifuged at 11000 rpm for 30 min; supernatant was taken for further use. The fraction was concentrated and subjected to PTLC. The Rf value of isolated apigenin was calculated (0.82. Purified material was also subjected to its IR spectra, LC-MS, NMR, and HPLC for structural elucidation. The apigenin so-obtained was subjected to antibacterial activity on five pathogenic bacterial strains like Pseudomonas aeruginosa, Salmonella typhimurium, Proteus mirabilis, Klebsiella pneumoniae and Enterobacter aerogenes; among all the bacterial strains, Salmonella typhimurium (17.36 ± 0.18 and Proteus mirabilis (19.12 ±  0.01 have shown maximum diameter of inhibition zone for flavonoid and remaining bacterial strains have shown moderate diameter of inhibition zone when compared with control values 14.56 ±  0.21 and 11.68 ± 0.13, respectively. The minimum inhibitory concentration (MIC of the flavonoid isolated from P. oleracea L. was tested at the concentration ranging from undiluted sample to 10 mg per mL of concentration. The minimum inhibition concentration (MIC for the flavonoid for all tested bacterial strains was found to be >4 mg per mL. Hence, the apigenin has antibacterial property and can be used to develop antibacterial drugs.

  2. Oxidative Stress Triggered by Apigenin Induces Apoptosis in a Comprehensive Panel of Human Cervical Cancer-Derived Cell Lines

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    Raquel P. Souza

    2017-01-01

    Full Text Available Recently, the cytotoxic effects of apigenin (4′,5,7-trihydroxyflavone, particularly its marked inhibition of cancer cell viability both in vitro and in vivo, have attracted the attention of the anticancer drug discovery field. Despite this, there are few studies of apigenin in cervical cancer, and these studies have mostly been conducted using HeLa cells. To evaluate the possibility of apigenin as a new therapeutic candidate for cervical cancer, we evaluated its cytotoxic effects in a comprehensive panel of human cervical cancer-derived cell lines including HeLa (human papillomavirus/HPV 18-positive, SiHa (HPV 16-positive, CaSki (HPV 16 and HPV 18-positive, and C33A (HPV-negative cells in comparison to a nontumorigenic spontaneously immortalized human epithelial cell line (HaCaT. Our results demonstrated that apigenin had a selective cytotoxic effect and could induce apoptosis in all cervical cancer cell lines which were positively marked with Annexin V, but not in HaCaT (control cells. Additionally, apigenin was able to induce mitochondrial redox impairment, once it increased ROS levels and H2O2, decreased the Δψm, and increased LPO. Still, apigenin was able to inhibit migration and invasion of cancer cells. Thus, apigenin appears to be a promising new candidate as an anticancer drug for cervical cancer induced by different HPV genotypes.

  3. Phenolic compounds apigenin, hesperidin and kaempferol reduce in vitro lipid accumulation in human adipocytes.

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    Gómez-Zorita, Saioa; Lasa, Arrate; Abendaño, Naiara; Fernández-Quintela, Alfredo; Mosqueda-Solís, Andrea; Garcia-Sobreviela, Maria Pilar; Arbonés-Mainar, Jose M; Portillo, Maria P

    2017-11-21

    Adipocytes derived from human mesenchymal stem cells (MSCs) are widely used to investigate adipogenesis. Taking into account both the novelty of these MSCs and the scarcity of studies focused on the effects of phenolic compounds, the aim of the present study was to analyze the effect of apigenin, hesperidin and kaempferol on pre-adipocyte and mature adipocytes derived from this type of cells. In addition, the expression of genes involved in TG accumulation was also measured. Pre-adipocytes were cultured from day 0 to day 8 and mature adipocytes for 48 h with the polyphenols at doses of 1, 10 and 25 µM. Apigenin did not show an anti-adipogenic action. Pre-adipocytes treated with hesperidin and kaempferol showed reduced TG content at the three experimental doses. Apigenin did not modify the expression of the main adipogenic genes (c/ebpβ, c/ebpα, pparγ and srebp1c), hesperidin inhibited genes involved in the three phases of adipogenesis (c/ebpβ, srebp1c and perilipin) and kaempferol reduced c/ebpβ. In mature adipocytes, the three polyphenols reduced TG accumulation at the dose of 25 µM, but not at lower doses. All compounds increased mRNA levels of atgl. Apigenin and hesperidin decreased fasn expression. The present study shows the anti-adipogenic effect and delipidating effects of apigenin, hesperidin and kaempferol in human adipocytes derived from hMSCs. While hesperidin blocks all the stages of adipogenesis, kaempferol only inhibits the early stage. Regarding mature adipocytes, the three compounds reduce TG accumulation by activating, at least in part, lipolysis, and in the case of hesperidin and apigenin, also by reducing lipogenesis. The present study shows for the first time the anti-adipogenic effect and delipidating effect of apigenin, hesperidin and kaempferol in human adipocytes derived from MSCs for the first time.

  4. Apigenin induces apoptosis by targeting inhibitor of apoptosis proteins and Ku70–Bax interaction in prostate cancer

    Science.gov (United States)

    Shukla, Sanjeev; Fu, Pingfu; Gupta, Sanjay

    2014-01-01

    Dysfunction of the apoptotic pathway in prostate cancer cells confers apoptosis resistance towards various therapies. A novel strategy to overcome resistance is to directly target the apoptotic pathway in cancer cells. Apigenin, an anticancer agent, selectively toxic to cancer cells induces cell cycle arrest and apoptosis through mechanisms which are not fully explored. In the present study we provide novel insight into the mechanisms of apoptosis induction by apigenin. Treatment of androgen-refractory human prostate cancer PC-3 and DU145 cells with apigenin resulted in dose-dependent suppression of XIAP, c-IAP1, c-IAP2 and survivin protein levels. Apigenin treatment resulted in significant decrease in cell viability and apoptosis induction with the increase of cytochrome C in time-dependent manner. These effects of apigenin were accompanied by decrease in Bcl-xL and Bcl-2 and increase in the active form of Bax protein. The apigenin-mediated increase in Bax was due to dissociation of Bax from Ku70 which is essential for apoptotic activity of Bax. Apigenin treatment resulted in the inhibition of class I histone deacetylases and HDAC1 protein expression, thereby increasing the acetylation of Ku70 and the dissociation of Bax resulting in apoptosis of cancer cells. Furthermore, apigenin significantly reduced HDAC1 occupancy at the XIAP promoter, suggesting that histone deacetylation might be critical for XIAP downregulation. These results suggest that apigenin targets inhibitor of apoptosis proteins and Ku70–Bax interaction in the induction of apoptosis in prostate cancer cells and in athymic nude mouse xenograft model endorsing its in vivo efficacy. PMID:24563225

  5. Apigenin ameliorates hypertension-induced cardiac hypertrophy and down-regulates cardiac hypoxia inducible factor-lα in rats.

    Science.gov (United States)

    Zhu, Zeng-Yan; Gao, Tian; Huang, Yan; Xue, Jie; Xie, Mei-Lin

    2016-04-01

    Apigenin is a natural flavonoid compound that can inhibit hypoxia-inducible factor (HIF)-1α expression in cultured tumor cells under hypoxic conditions. Hypertension-induced cardiac hypertrophy is always accompanied by abnormal myocardial glucolipid metabolism due to an increase of HIF-1α. However, whether or not apigenin may ameliorate the cardiac hypertrophy and abnormal myocardial glucolipid metabolism remains unknown. This study aimed to examine the effects of apigenin. Rats with cardiac hypertrophy induced by renovascular hypertension were treated with apigenin 50-100 mg kg(-1) (the doses can be achieved by pharmacological or dietary supplementation for an adult person) by gavage for 4 weeks. The results showed that after treatment with apigenin, the blood pressure, heart weight, heart weight index, cardiomyocyte cross-sectional area, serum angiotensin II, and serum and myocardial free fatty acids were reduced. It is important to note that apigenin decreased the expression level of myocardial HIF-1α protein. Moreover, apigenin simultaneously increased the expression levels of myocardial peroxisome proliferator-activated receptor (PPAR) α, carnitine palmitoyltransferase (CPT)-1, and pyruvate dehydrogenase kinase (PDK)-4 proteins and decreased the expression levels of myocardial PPARγ, glycerol-3-phosphate acyltransferase genes (GPAT), and glucose transporter (GLUT)-4 proteins. These findings demonstrated that apigenin could improve hypertensive cardiac hypertrophy and abnormal myocardial glucolipid metabolism in rats, and its mechanisms might be associated with the down-regulation of myocardial HIF-1α expression and, subsequently increasing the expressions of myocardial PPARα and its target genes CPT-1 and PDK-4, and decreasing the expressions of myocardial PPARγ and its target genes GPAT and GLUT-4.

  6. Apigenin promotes TRAIL-mediated apoptosis regardless of ROS generation.

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    Kang, Chang-Hee; Molagoda, Ilandarage Menu Neelaka; Choi, Yung Hyun; Park, Cheol; Moon, Dong-Oh; Kim, Gi-Young

    2018-01-01

    Apigenin is a bioactive flavone in several herbs including parsley, thyme, and peppermint. Apigenin possesses anti-cancer and anti-inflammatory properties; however, whether apigenin enhances TRAIL-mediated apoptosis in cancer cells is unknown. In the current study, we found that apigenin enhanced TRAIL-induced apoptosis by promoting caspase activation and death receptor 5 (DR5) expression and a chimeric antibody against DR5 completely blocked the apoptosis. Apigenin also upregulated reactive oxygen species (ROS) generation; however, intriguingly, ROS inhibitors, glutathione (GSH) or N-acetyl-l-cysteine (NAC), moderately increased apigenin/TRAIL-induced apoptosis. Additional results showed that an autophagy inducer, rapamycin, enhanced apigenin/TRAIL-mediated apoptosis by a slight increase of ROS generation. Accordingly, NAC and GSH rather decreased apigenin-induced autophagy formation, suggesting that apigenin-induced ROS generation increased autophagy formation. However, autophagy inhibitors, bafilomycin (BAF) and 3-methyladenine (3-MA), showed different result in apigenin/TRAIL-mediated apoptosis without ROS generation. 3-MA upregulated the apoptosis but remained ROS levels; however, no changes on apoptosis and ROS generation were observed by BAF treatment. Taken together, these findings reveal that apigenin enhances TRAIL-induced apoptosis by activating apoptotic caspases by upregulating DR5 expression regardless of ROS generation, which may be a promising strategy for an adjuvant of TRAIL. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Novel Apigenin Based Small Molecule that Targets Snake Venom Metalloproteases

    Science.gov (United States)

    Anusha, Sebastian; Hemshekhar, Mahadevappa; Chandra Nayaka, Siddaiah; Kemparaju, Kempaiah; Basappa; Girish, Kesturu S.; Rangappa, Kanchugarakoppal S.

    2014-01-01

    The classical antivenom therapy has appreciably reduced snakebite mortality rate and thus is the only savior drug available. Unfortunately, it considerably fails to shield the viper bite complications like hemorrhage, local tissue degradation and necrosis responsible for severe morbidity. Moreover, the therapy is also tagged with limitations including anaphylaxis, serum sickness and poor availability. Over the last decade, snake venom metalloproteases (SVMPs) are reported to be the primary component responsible for hemorrhage and tissue degradation at bitten site. Thus, antivenom inability to offset viper venom-induced local toxicity has been a basis for an insistent search for SVMP inhibitors. Here we report the inhibitory effect of compound 5d, an apigenin based molecule against SVMPs both in silico and in vivo. Several apigenin analogues are synthesized using multicomponent Ugi reactions. Among them, compound 5d effectively abrogated Echis carinatus (EC) venom-induced local hemorrhage, tissue necrosis and myotoxicity in a dose dependant fashion. The histopathological study further conferred effective inhibition of basement membrane degradation, and accumulation of inflammatory leucocytes at the site of EC venom inoculation. The compound also protected EC venom-induced fibrin and fibrinogen degradation. The molecular docking of compound 5d and bothropasin demonstrated the direct interaction of hydroxyl group of compound with Glu146 present in hydrophobic pocket of active site and does not chelate Zn2+. Hence, it is concluded that compound 5d could be a potent agent in viper bite management. PMID:25184206

  8. Pharmacokinetic properties and drug interactions of apigenin, a natural flavone.

    Science.gov (United States)

    Tang, Ding; Chen, Keli; Huang, Luqi; Li, Juan

    2017-03-01

    Apigenin, a natural flavone, is widely distributed in plants such as celery, parsley and chamomile. It is present principally as glycosylated in nature. Higher intake of apigenin could reduce the risk of chronic diseases. It has gained particular interest in recent years as a beneficial, health-promoting agent with low intrinsic toxicity. Areas covered: This review summarizes and the absorption, distribution, metabolism and excretion (ADME) properties of apigenin, and drug-drug interaction of apigenin. Expert opinion: Since apigenin is a bioactive plant flavone and is widely distributed in common food, its consumption through the diet is recommended. Apigenin-enriched drugs are better for some chronic diseases, but may affect animal and human health if present in the daily diet. Dietary or therapeutic apigenin has value as a good cellular regulator in cancer, especially cancers of the gastrointestinal tract. Due to apigenin's limitations on absorption and bioavailability, novel carriers would need to be developed to enhance the oral bioavailability of apigenin. Further research about its ADME properties and drug-drug interactions are needed before apigenin can be brought to clinical trials.

  9. Apigenin suppresses migration and invasion of transformed cells through down-regulation of C-X-C chemokine receptor 4 expression

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    Wang, Lei; Kuang, Lisha; Hitron, John Andrew; Son, Young-Ok; Wang, Xin; Budhraja, Amit [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Lee, Jeong-Chae [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Institute of Oral Biosciences and BK21 Program, Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Pratheeshkumar, Poyil [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Chen, Gang [Department of Internal Medicine, University of Kentucky College of Medicine, Lexington, KY 40536 (United States); Zhang, Zhuo [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Luo, Jia [Department of Internal Medicine, University of Kentucky College of Medicine, Lexington, KY 40536 (United States); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States)

    2013-10-01

    Environmental exposure to arsenic is known to cause various cancers. There are some potential relationships between cell malignant transformation and C-X-C chemokine receptor type 4 (CXCR4) expressions. Metastasis, one of the major characteristics of malignantly transformed cells, contributes to the high mortality of cells. CXCR4 and its natural chemokine ligand C-X-C motif ligand 12 (CXCL12) play a critical role in metastasis. Therefore, identification of nutritional factors which are able to inhibit CXCR4 is important for protection from environmental arsenic-induced carcinogenesis and for abolishing metastasis of malignantly transformed cells. The present study demonstrates that apigenin (4′,5,7-trihydroxyflavone), a natural dietary flavonoid, suppressed CXCR4 expression in arsenic-transformed Beas-2B cells (B-AsT) and several other types of transformed/cancer cells in a dose- and time-dependent manner. Neither proteasome nor lysosome inhibitor had any effect in reducing the apigenin-induced down-regulation of CXCR4, indicating that apigenin-induced down-regulation of CXCR4 is not due to proteolytic degradation. The down-regulation of CXCR4 is mainly due to the inhibition of nuclear factor κB (NF-κB) transcriptional activity. Apigenin also abolished migration and invasion of transformed cells induced by CXCL12. In a xenograft mouse model, apigenin down-regulated CXCR4 expression and suppressed tumor growth. Taken together, our results show that apigenin is a novel inhibitor of CXCR4 expression. This dietary flavonoid has the potential to suppress migration and invasion of transformed cells and prevent environmental arsenic-induced carcinogenesis. - Highlights: • Apigenin has a potential in preventing environmental arsenic induced carcinogenesis. • Apigenin suppresses CXCR4 in malignant transformed cells in vitro and in vivo. • The down-regulation of CXCR4 is mainly due to inhibition of NF-κB activity.

  10. Synthesis and Biological Evaluation of Apigenin Derivatives as Antibacterial and Antiproliferative Agents

    Directory of Open Access Journals (Sweden)

    Jinyi Wang

    2013-09-01

    Full Text Available Two series of apigenin [5,7-dihydroxy-2-(4-hydroxyphenyl-4H-chromen-4-one] derivatives, 3a–3j and 4a–4j, were synthesized. The apigenin and alkyl amines moieties of these compounds were separated by C2 or C3 spacers, respectively. The chemical structures of the apigenin derivatives were confirmed using 1H-NMR, 13C-NMR, and electrospray ionization mass spectroscopy. The in vitro antibacterial and antiproliferative activities of all synthesized compounds were determined. Among the tested compounds, 4a–4j displayed significant antibacterial activity against the tested strains (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. Additionally, 4i showed the best inhibitory activity with minimum inhibitory concentrations of 1.95, 3.91, 3.91, and 3.91 μg/mL against S. aureus, B. subtilis, E. coli, and P. aeruginosa, respectively. The antiproliferative activity of the apigenin derivatives was evaluated by an MTT [3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide] assay. We determined that 4a–4j displayed better growth inhibition activity against four human cancer cell lines, namely, human lung (A549, human cervical (HeLa, human hepatocellular liver (HepG2, and human breast (MCF-7 cancer cells, than the parent apigenin. Compound 4j was found to be the most active antiproliferative compound against the selected cancer cells. Structure-activity relationships were also discussed based on the obtained experimental data.

  11. Oxidation pathways underlying the pro-oxidant effects of apigenin.

    Science.gov (United States)

    Andueza, Aitor; García-Garzón, Antonia; Ruiz de Galarreta, Marina; Ansorena, Eduardo; Iraburu, María J; López-Zabalza, María J; Martínez-Irujo, Juan J

    2015-10-01

    Apigenin, a natural flavone, is emerging as a promising compound for the treatment of several diseases. One of the hallmarks of apigenin is the generation of intracellular reactive oxygen species (ROS), as judged by the oxidation of reduced dichlorofluorescein derivatives seen in many cell types. This study aimed to reveal some mechanisms by which apigenin can be oxidized and how apigenin-derived radicals affect the oxidation of 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein (H(2)DCF), a probe usually employed to detect intracellular ROS. Apigenin induced a rapid oxidation of H(2)DCF in two different immortalized cell lines derived from rat and human hepatic stellate cells. However, apigenin did not generate ROS in these cells, as judged by dihydroethidium oxidation and extracellular hydrogen peroxide production. In cell-free experiments we found that oxidation of apigenin leads to the generation of a phenoxyl radical, which directly oxidizes H(2)DCF with catalytic amounts of hydrogen peroxide. The net balance of the reaction was the oxidation of the probe by molecular oxygen due to redox cycling of apigenin. This flavonoid was also able to deplete NADH and glutathione by a similar mechanism. Interestingly, H(2)DCF oxidation was significantly accelerated by apigenin in the presence of horseradish peroxidase and xanthine oxidase, but not with other enzymes showing peroxidase-like activity, such as cytochrome c or catalase. We conclude that in cells treated with apigenin oxidation of reduced dichlorofluorescein derivatives does not measure intracellular ROS and that pro- and antioxidant effects of flavonoids deduced from these experiments are inconclusive and must be confirmed by other techniques. Copyright © 2015. Published by Elsevier Inc.

  12. Apigenin has anti-atrophic gastritis and anti-gastric cancer progression effects in Helicobacter pylori-infected Mongolian gerbils.

    Science.gov (United States)

    Kuo, Chao-Hung; Weng, Bi-Chuang; Wu, Chun-Chieh; Yang, Sheau-Fang; Wu, Deng-Chang; Wang, Yuan-Chuen

    2014-02-12

    Apigenin, one of the most common flavonoids, is abundant in celery, parsley, chamomile, passionflower, and other vegetables and fruits. Celery is recognized as a medicinal vegetable in Oriental countries to traditionally treat inflammation, swelling, blood pressure, serum lipid, and toothache. In this study, we investigated apigenin treatment effects on Helicobacter pylori-induced atrophic gastritis and gastric cancer progression in Mongolian gerbils. Five to eight-week-old Mongolian gerbils were inoculated with Helicobacter pylori for four weeks without (atrophic gastritis group) or with N'-methyl-N'-nitro-N-nitroso-guanidine (MNNG) (gastric cancer group) in drinking water, and were then rested for two weeks. During the 7th-32th (atrophic gastritis group) or the 7th-52th (gastric cancer group) weeks, they were given various doses (0-60 mg/kgbw/day) of apigenin. At the end of the 32th (atrophic gastritis group) or the 52th (atrophic gastritis group) week, all Mongolian gerbils were sacrificed using the CO2 asphyxia method. The histological changes of Helicobacter pylori colonization, neutrophil and monocyte infiltrations, and atrophic gastritis in both atrophic gastritis and gastric cancer Mongolian gerbils were examined using immunohistochemistry stain and Sydney System scoring. Apigenin treatments (30-60 mg/kgbw/day) effectively decreased atrophic gastritis (atrophic gastritis group) and dysplasia/gastric cancer (gastric cancer group) rates in Mongolian gerbils. Apigenin treatment (60 mg/kgbw/day) significantly decreased Helicobacter pylori colonization and Helicobacter pylori-induced histological changes of neutrophil and monocyte infiltrations and atrophic gastritis in both atrophic gastritis and gastric cancer Mongolian gerbils. Apigenin has the remarkable ability to inhibit Helicobacter pylori-induced atrophic gastritis and gastric cancer progression as well as possessing potent anti-gastric cancer activity. Copyright © 2013 Elsevier Ireland Ltd. All rights

  13. Oxidative stress triggered by naturally occurring flavone apigenin results in senescence and chemotherapeutic effect in human colorectal cancer cells

    Directory of Open Access Journals (Sweden)

    Kacoli Banerjee

    2015-08-01

    Full Text Available Recent studies involving phytochemical polyphenolic compounds have suggested flavones often exert pro-oxidative effect in vitro against wide array of cancer cell lines. The aim of this study was to evaluate the in-vitro pro-oxidative activity of apigenin, a plant based flavone against colorectal cancer cell lines and investigate cumulative effect on long term exposure. In the present study, treatment of colorectal cell lines HT-29 and HCT-15 with apigenin resulted in anti-proliferative and apoptotic effects characterized by biochemical and morphological changes, including loss of mitochondrial membrane potential which aided in reversing the impaired apoptotic machinery leading to negative implications in cancer pathogenesis. Apigenin induces rapid free radical species production and the level of oxidative damage was assessed by qualitative and quantitative estimation of biochemical markers of oxidative stress. Increased level of mitochondrial superoxide suggested dose dependent mitochondrial oxidative damage which was generated by disruption in anti-apoptotic and pro-apoptotic protein balance. Continuous and persistent oxidative stress induced by apigenin at growth suppressive doses over extended treatment time period was observed to induce senescence which is a natural cellular mechanism to attenuate tumor formation. Senescence phenotype inducted by apigenin was attributed to changes in key molecules involved in p16-Rb and p53 independent p21 signaling pathways. Phosphorylation of retinoblastoma was inhibited and significant up-regulation of p21 led to simultaneous suppression of cyclins D1 and E which indicated the onset of senescence. Pro-oxidative stress induced premature senescence mediated by apigenin makes this treatment regimen a potential chemopreventive strategy and an in vitro model for aging research.

  14. Oxidative stress triggered by naturally occurring flavone apigenin results in senescence and chemotherapeutic effect in human colorectal cancer cells.

    Science.gov (United States)

    Banerjee, Kacoli; Mandal, Mahitosh

    2015-08-01

    Recent studies involving phytochemical polyphenolic compounds have suggested flavones often exert pro-oxidative effect in vitro against wide array of cancer cell lines. The aim of this study was to evaluate the in-vitro pro-oxidative activity of apigenin, a plant based flavone against colorectal cancer cell lines and investigate cumulative effect on long term exposure. In the present study, treatment of colorectal cell lines HT-29 and HCT-15 with apigenin resulted in anti-proliferative and apoptotic effects characterized by biochemical and morphological changes, including loss of mitochondrial membrane potential which aided in reversing the impaired apoptotic machinery leading to negative implications in cancer pathogenesis. Apigenin induces rapid free radical species production and the level of oxidative damage was assessed by qualitative and quantitative estimation of biochemical markers of oxidative stress. Increased level of mitochondrial superoxide suggested dose dependent mitochondrial oxidative damage which was generated by disruption in anti-apoptotic and pro-apoptotic protein balance. Continuous and persistent oxidative stress induced by apigenin at growth suppressive doses over extended treatment time period was observed to induce senescence which is a natural cellular mechanism to attenuate tumor formation. Senescence phenotype inducted by apigenin was attributed to changes in key molecules involved in p16-Rb and p53 independent p21 signaling pathways. Phosphorylation of retinoblastoma was inhibited and significant up-regulation of p21 led to simultaneous suppression of cyclins D1 and E which indicated the onset of senescence. Pro-oxidative stress induced premature senescence mediated by apigenin makes this treatment regimen a potential chemopreventive strategy and an in vitro model for aging research. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Topical Apigenin Alleviates Cutaneous Inflammation in Murine Models

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    Mao-Qiang Man

    2012-01-01

    Full Text Available Herbal medicines have been used in preventing and treating skin disorders for centuries. It has been demonstrated that systemic administration of chrysanthemum extract exhibits anti-inflammatory properties. However, whether topical applications of apigenin, a constituent of chrysanthemum extract, influence cutaneous inflammation is still unclear. In the present study, we first tested whether topical applications of apigenin alleviate cutaneous inflammation in murine models of acute dermatitis. The murine models of acute allergic contact dermatitis and acute irritant contact dermatitis were established by topical application of oxazolone and phorbol 12-myristate 13-acetate (TPA, respectively. Inflammation was assessed in both dermatitis models by measuring ear thickness. Additionally, the effect of apigenin on stratum corneum function in a murine subacute allergic contact dermatitis model was assessed with an MPA5 physiology monitor. Our results demonstrate that topical applications of apigenin exhibit therapeutic effects in both acute irritant contact dermatitis and allergic contact dermatitis models. Moreover, in comparison with the vehicle treatment, topical apigenin treatment significantly reduced transepidermal water loss, lowered skin surface pH, and increased stratum corneum hydration in a subacute murine allergic contact dermatitis model. Together, these results suggest that topical application of apigenin could provide an alternative regimen for the treatment of dermatitis.

  16. Luteolin and Apigenin Attenuate 4-Hydroxy-2-Nonenal-Mediated Cell Death through Modulation of UPR, Nrf2-ARE and MAPK Pathways in PC12 Cells

    Science.gov (United States)

    Wu, Pei-Shan; Yen, Jui-Hung; Kou, Mei-Chun; Wu, Ming-Jiuan

    2015-01-01

    Luteolin and apigenin are dietary flavones and exhibit a broad spectrum of biological activities including antioxidant, anti-inflammatory, anti-cancer and neuroprotective effects. The lipid peroxidation product 4-hydroxy-2-nonenal (4-HNE) has been implicated as a causative agent in the development of neurodegenerative disorders. This study investigates the cytoprotective effects of luteolin and apigenin against 4-HNE-mediated cytotoxicity in neuronal-like catecholaminergic PC12 cells. Both flavones restored cell viability and repressed caspase-3 and PARP-1 activation in 4-HNE-treated cells. Luteolin also mitigated 4-HNE-mediated LC3 conversion and reactive oxygen species (ROS) production. Luteolin and apigenin up-regulated 4-HNE-mediated unfolded protein response (UPR), leading to an increase in endoplasmic reticulum chaperone GRP78 and decrease in the expression of UPR-targeted pro-apoptotic genes. They also induced the expression of Nrf2-targeted HO-1 and xCT in the absence of 4-HNE, but counteracted their expression in the presence of 4-HNE. Moreover, we found that JNK and p38 MAPK inhibitors significantly antagonized the increase in cell viability induced by luteolin and apigenin. Consistently, enhanced phosphorylation of JNK and p38 MAPK was observed in luteolin- and apigenin-treated cells. In conclusion, this result shows that luteolin and apigenin activate MAPK and Nrf2 signaling, which elicit adaptive cellular stress response pathways, restore 4-HNE-induced ER homeostasis and inhibit cytotoxicity. Luteolin exerts a stronger cytoprotective effect than apigenin possibly due to its higher MAPK, Nrf2 and UPR activation, and ROS scavenging activity. PMID:26087007

  17. Synthesis, Cytotoxic Activity, and DNA Binding Properties of Copper (II) Complexes with Hesperetin, Naringenin, and Apigenin

    OpenAIRE

    Tan, Mingxiong; Zhu, Jinchan; Pan, Yingming; Chen, Zhenfeng; Liang, Hong; Liu, Huagang; Wang, Hengshan

    2009-01-01

    Complexes of copper (II) with hesperetin, naringenin, and apigenin of general composition [CuL2(H2O)2]⋅nH2O (1–3) have been synthesized and characterized by elemental analysis, UV-Vis, FT-IR, ESI-MS, and TG-DTG thermal analysis. The free ligands and the metal complexes have been tested in vitro against human cancer cell lines hepatocellular carcinoma (HepG-2), gastric carcinomas (SGC-7901), and cervical carcinoma (HeLa). Complexes 1 and 3 were found to exhibit growth inhibition of SGC-79...

  18. Apigenin as an anti-quinolone-resistance antibiotic.

    Science.gov (United States)

    Morimoto, Yuh; Baba, Tadashi; Sasaki, Takashi; Hiramatsu, Keiichi

    2015-12-01

    We previously reported the first 'reverse antibiotic' (RA), nybomycin (NYB), which showed a unique antimicrobial activity against Staphylococcus aureus strains. NYB specifically suppressed the growth of quinolone-resistant S. aureus strains but was not effective against quinolone-susceptible strains. Although NYB was first reported in 1955, little was known about its unique antimicrobial activity because it was before the synthesis of the first quinolone ('old quinolone'), nalidixic acid, in 1962. Following our re-discovery of NYB, we looked for other RAs among natural substances that act on quinolone-resistant bacteria. Commercially available flavones were screened against S. aureus, including quinolone-resistant strains, and their minimum inhibitory concentrations (MICs) were compared using the microbroth dilution method. Some of the flavones screened showed stronger antimicrobial activity against quinolone-resistant strains than against quinolone-susceptible ones. Amongst them, apigenin (API) was the most potent in its RA activity. DNA cleavage assay showed that API inhibited DNA gyrase harbouring the quinolone resistance mutation gyrA(Ser84Leu) but did not inhibit 'wild-type' DNA gyrase that is sensitive to levofloxacin. An API-susceptible S. aureus strain Mu50 was also selected using agar plates containing 20mg/L API. Whole-genome sequencing of selected mutant strains was performed and frequent back-mutations (reverse mutations) were found among API-resistant strains derived from the API-susceptible S. aureus strains. Here we report that API represents another molecular class of natural antibiotic having RA activity against quinolone-resistant bacteria. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Acute exposure of apigenin induces hepatotoxicity in Swiss mice.

    Directory of Open Access Journals (Sweden)

    Prabhat Singh

    Full Text Available Apigenin, a dietary flavonoid, is reported to have several therapeutic effects in different diseases including cancer. Toxicity of Apigenin is however, least explored, and reports are scanty in literature. This warrants dose-specific evaluation of toxicity in vivo. In the present study, Apigenin was administered intraperitoneally to Swiss mice at doses of 25, 50, 100 and 200 mg/kg. Serum levels of alanine amino transferase (ALT, aspartate amino transferase (AST and alkaline phosphatase (ALP were measured along with the examination of liver histology, reactive oxygen species (ROS in blood, lipid peroxidation (LPO, glutathione level, superoxide dismutase activity, catalase activity, glutathione S-transferase activity and gene expression in liver tissue. Increase in ALT, AST, ALP, ROS, ratio of oxidized to reduced glutathione (GSSG/GSH and LPO, altered enzyme activities along with damaged histoarchitecture in the liver of 100 or 200 mg/kg Apigenin treated animals were found. Microarray analysis revealed the differential expression of genes that correspond to different biologically relevant pathways including oxidative stress and apoptosis. In conclusion, these results suggested the oxidative stress induced liver damage which may be due to the regulation of multiple genes by Apigenin at higher doses in Swiss mice.

  20. Apigenin enhances skeletal muscle hypertrophy and myoblast differentiation by regulating Prmt7

    OpenAIRE

    Jang, Young Jin; Son, Hyo Jeong; Choi, Yong Min; Ahn, Jiyun; Jung, Chang Hwa; Ha, Tae Youl

    2017-01-01

    Apigenin, a natural flavone abundant in various plant-derived foods including parsley and celery, has been shown to prevent inflammation and inflammatory diseases. However, the effect of apigenin on skeletal muscle hypertrophy and myogenic differentiation has not previously been elucidated. Here, we investigated the effects of apigenin on quadricep muscle weight and running distance using C57BL/6 mice on an accelerating treadmill. Apigenin stimulated mRNA expression of MHC (myosin heavy chain...

  1. Apigenin impacts growth of the gut microbiota and alters gene expression of Enterococcus

    Science.gov (United States)

    Apigenin is a major dietary flavonoid widely distributed in plants with many bioactivities. Apigenin reaches the colon region intact and interacts with the human gut microbiota; however, there is little research on how apigenin affects gut bacteria. This study investigated the effect of pure apigeni...

  2. Apigenin suppresses GLUT-1 and p-AKT expression to enhance the chemosensitivity to cisplatin of laryngeal carcinoma Hep-2 cells: an in vitro study.

    Science.gov (United States)

    Xu, Ying-Ying; Wu, Ting-Ting; Zhou, Shui-Hong; Bao, Yang-Yang; Wang, Qin-Ying; Fan, Jun; Huang, Ya-Ping

    2014-01-01

    Glucose transporter-1 (GLUT-1) and PI3K/Akt are known to be closely involved in resistance to chemotherapy. Co-targeted therapy reducing GLUT-1 expression and PI3K/Akt pathway activity may overcome the chemoresistance of human cancers. Apigenin may inhibit the expression of GLUT-1 and the PI3K/Akt pathway. We hypothesized that over-expression of GLUT-1 and p-Akt was associated with the resistance to cisplatin of laryngeal carcinoma Hep-2 cells. We explored whether apigenin inhibited GLUT-1 and p-Akt, resulting in sensitization of laryngeal carcinoma Hep-2 cells to cisplatin. Real-time RT-PCR and Western blotting confirmed the presence of GLUT-1 mRNA, and GLUT-1 and p-Akt proteins in Hep-2 cells. We found that resistance or insensitivity of Hep-2 cells to cisplatin might be associated with such expression. Apigenin markedly enhanced the cisplatin-induced suppression of Hep-2 cell growth. This effect was concentration- and time-dependent. Thus apigenin may significantly reduce the levels of GLUT-1 mRNA, and GLUT-1 and p-Akt proteins, in cisplatin-treated Hep-2 cells, in a concentration- and time-dependent manner. To conclude, overexpression of GLUT-1 mRNA may be associated with the resistance to cisplatin of laryngeal carcinoma Hep-2 cells. Apigenin may enhance the sensitivity to cisplatin of laryngeal carcinoma cells via inhibition of GLUT-1 and p-Akt expression.

  3. Effect of apigenin, kaempferol and resveratrol on the gene expression and protein secretion of tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) in RAW-264.7 macrophages.

    Science.gov (United States)

    Palacz-Wrobel, Marta; Borkowska, Paulina; Paul-Samojedny, Monika; Kowalczyk, Malgorzata; Fila-Danilow, Anna; Suchanek-Raif, Renata; Kowalski, Jan

    2017-09-01

    Polyphenols such as apigenin, kaempferol or resveratrol are typically found in plants, including fruits, vegetables, herbs and spices, which have a wide range of biological functions such as antioxidative, anti-inflammatory, vasodilative, anticoagulative and proapoptotic. Discovering such multifunctional compounds in widely consumed plant-based products - ones that both inhibit the release of TNF-α from tissue macrophages and at the same time enhance the secretion of IL-10 - would be an important signpost in the quest for effective pharmacological treatment of numerous diseases that have an inflammatory etiology. The aim of the study is to investigate the impact of biologically active polyphenols such as apigenin, resveratrol and kaempferol on gene expression and protein secretion of IL-10 and TNF-α in line RAW-264.7. Cells were cultured under standard conditions. IL-10 and TNF-α genes expression were examined using QRT-PCR and to assess cytokines concentration ELISA have been used. Apigenin, kaempferol and resveratrol at a dose 30μM significantly decrease the TNF-α expression and secretion. Apigenin decrease the IL-10 expression and secretion. Furthermore, increase in IL-10 secretion after administration of kaempferol and resveratrol were observed. In the process of administration of tested compounds before LPS, which activate macrophages, decrease of TNF-α secretion after apigenin and kaempferol and increase of IL-10 secretion after resveratrol were observed. The results of present work indicate that 1) apigenin, resveratrol and kaempferol may reduce the intensity of inflammatory processes by inhibiting the secretion of proinflammatory cytokine TNF-α, and resveratrol and kaempferol additionally by increasing the secretion of anti-inflammatory cytokine IL-10 2) the studies indicate the potentially beneficial - anti-inflammatory - impact of diet rich in products including apigenin, resveratrol and kaempferol. Copyright © 2017 Elsevier Masson SAS. All rights

  4. Antidiarrhoeal assessment of hydroalcoholic and hexane extracts of Dracocephalum kotschyi Boiss. and apigenin in mice.

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    Sadraei, Hassan; Asghari, Gholamreza; Shahverdi, Farzaneh

    2016-01-01

    Dracocephalum kotschyi Boiss, a member of Labiatae family, is a native plant to Iran, which has been reported to have immunomodulatory, antihyperlipidemic and antispasmodic activities. The objective of this research was to study the antispasmodic and antidiarrhoeal activities of hydroalcoholic and hexane extracts of D. kotschyi in mice. Furthermore, the antidiarrhoeal and antispasmodic effect of apigenin, a flavonoid constituent of D. kotschyi, was also studied. Hydroalcoholic and hexane extracts were obtained from aerial part of D. kotschyi using percolation method. Antispasmodic effect of the test compounds was assessed by measurement of small intestine transit following oral administration of a charcoal meal. Diarrhoea was induced by administration of either castor oil (0.5 ml) or magnesium sulphate (MgSO4) (10% w/v solution). Both the hydroalcoholic and hexane extracts of D. kotschyi (10 and 20 mg/kg) reduced the intestinal charcoal meal transit. Loperamide (2 mg/kg) and apigenin (2 and 10 mg/kg) inhibited intestinal movement of the charcoal meal and also inhibited castor oil and MgSO4-induced diarrhoea. The hydroalcoholic and hexane extracts of D. kotschyi (10 and 20 mg/kg) also significantly inhibited the castor oil and MgSO4-induced diarrhoea in mice in comparison with the vehicle-treated control groups. This study confirms that both the hydroalcoholic and hexane extracts of D. kotschyi has antispasmodic and antidiarrhoeal properties in vivo and could be a suitable remedy for treatment of gastrointestinal disorders in which smooth muscle spasm and/or diarrhoea plays a significant roles.

  5. Topical apigenin improves epidermal permeability barrier homoeostasis in normal murine skin by divergent mechanisms.

    Science.gov (United States)

    Hou, Maihua; Sun, Richard; Hupe, Melanie; Kim, Peggy L; Park, Kyungho; Crumrine, Debra; Lin, Tzu-Kai; Santiago, Juan Luis; Mauro, Theodora M; Elias, Peter M; Man, Mao-Qiang

    2013-03-01

    The beneficial effects of certain herbal medicines on cutaneous function have been appreciated for centuries. Among these agents, chrysanthemum extract, apigenin, has been used for skin care, particularly in China, for millennia. However, the underlying mechanisms by which apigenin benefits the skin are not known. In this study, we first determined whether topical apigenin positively influences permeability barrier homoeostasis, and then the basis thereof. Hairless mice were treated topically with either 0.1% apigenin or vehicle alone twice daily for 9 days. At the end of the treatments, permeability barrier function was assessed with either an electrolytic water analyzer or a Tewameter. Our results show that topical apigenin significantly enhanced permeability barrier homoeostasis after tape stripping, although basal permeability barrier function remained unchanged. Improved barrier function correlated with enhanced filaggrin expression and lamellar body production, which was paralleled by elevated mRNA levels for the epidermal ABCA12. The mRNA levels for key lipid synthetic enzymes also were upregulated by apigenin. Finally, both cathelicidin-related peptide and mouse beta-defensin 3 immunostaining were increased by apigenin. We conclude that topical apigenin improves epidermal permeability barrier function by stimulating epidermal differentiation, lipid synthesis and secretion, as well as cutaneous antimicrobial peptide production. Apigenin could be useful for the prevention and treatment of skin disorders characterized by permeability barrier dysfunction, associated with reduced filaggrin levels and impaired antimicrobial defenses, such as atopic dermatitis. © 2013 John Wiley & Sons A/S.

  6. Enhancement of pentobarbital-induced sleep by apigenin through chloride ion channel activation.

    Science.gov (United States)

    Kim, Jae-Wook; Kim, Chung-Soo; Hu, Zhenzhen; Han, Jin-Yi; Kim, Si Kwan; Yoo, Sung-Kwang; Yeo, Yeong Man; Chong, Myong Soo; Lee, Kinam; Hong, Jin Tae; Oh, Ki-Wan

    2012-02-01

    This experiment was performed to investigate whether apigenin has hypnotic effects and/or enhances pentobarbital-induced sleep behaviors through the GABAergic systems. Apigenin prolonged sleep time induced by pentobarbital similar to muscimol, a GABA(A) receptors agonist. Apigenin also increased sleep rate and sleep time in the combined administration with pentobarbital at the sub-hypnotic dosage, and showed synergic effects with muscimol in potentiating sleep onset and enhancing sleep time induced by pentobarbital. In addition, both of apigeinin and pentobarbital increased chloride influx in primary cultured cerebellar granule cells. Apigenin increased glutamate decarboxylase (GAD) and had no effect on the expression of GABA(A) receptor α-, β-, γ-subunits in n hippocampus of mouse brain, showing different expression of subunits from pentobarbital treatment group. In conclusion, it is suggested that apigenin augments pentobarbital-induced sleep behaviors through chloride ion channel activation.

  7. Anti-mutagenic and Pro-apoptotic Effects of Apigenin on Human Chronic Lymphocytic Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Mehrdad Hashemi

    2010-09-01

    Full Text Available "nDiet can play a vital role in cancer prevention. Nowadays the scientists are looking for food materials which can potentially prevent the cancer occurrence. The purpose of this research is to examine anti-mutagenic and apoptotic effects of apigenin in human lymphoma cells. In present study human chronic lymphocytic leukemia (Eheb cell line were cultured in RPMI 1640 (Sigma, supplemented with 10% fetal calf serum, penicillin-streptomycin, L-glutamine and incubated at 37 ºC for 2 days. In addition cancer cell line was treated by and apigenin and cellular vital capacity was determined by MTT assay. Then effect of apigenin in human lymphoma B cells was examined by flow cytometry techniques. The apigenin was subsequently evaluated in terms of anti-mutagenic properties by a standard reverse mutation assay (Ames test. This was performed with histidine auxotroph strain of Salmonella typhimurium (TA100. Thus, it requires histidine from a foreign supply to ensure its growth. The aforementioned strain gives rise to reverted colonies when expose to sodium azide as a carcinogen substance. During MTT assay, human chronic lymphocytic leukemia revealed to have a meaningful cell death when compared with controls (P<0.01 Apoptosis was induced suitably after 48 hours by flow cytometry assay. In Ames test apigenin prevented the reverted mutations and the hindrance percent of apigenin was 98.17%.These results have revealed apigenin induced apoptosis in human lymphoma B cells in vitro.

  8. Impact of apigenin and kaempferol on human head and neck squamous cell carcinoma

    Science.gov (United States)

    Swanson, Hollie I.; Choi, Eun-Young; Helton, W. Brian; Gairola, C. Gary; Valentino, Joseph

    2014-01-01

    Objective Apigenin and kaempferol are plant flavonoids with reported chemopreventive activities. This study aimed to determine the effect of apigenin and kaempferol on cell viability in cultured cells derived from the pharynx (FaDu cell line), an oral cavity carcinoma (PCI-13 cell line), and a metastatic lymph node (PCI-15B cell line) and in explanted FaDu cells. Study Design The in vitro viability of FaDu, PCI-13, and PCI-15B cells treated with apigenin and kaempferol was determined. Tumor growth of FaDu explants was evaluated in athymic mice that were gavaged with either apigenin or kaempferol. Results Although apigenin and kaempferol treatment decreased viability of cells in vitro, cell-type-dependent differences in responsiveness were observed. In vivo apigenin treatment significantly increased the tumor size of FaDu explants. Results obtained using kaempferol were similar. Conclusions The in vitro decrease in FaDu cell viability by apigenin and kaempferol was not observed in in vivo tumor explants using the conditions described in this study. PMID:24439916

  9. AgFNS overexpression increase apigenin and decrease anthocyanins in petioles of transgenic celery.

    Science.gov (United States)

    Tan, Guo-Fei; Ma, Jing; Zhang, Xin-Yue; Xu, Zhi-Sheng; Xiong, Ai-Sheng

    2017-10-01

    Apigenin and anthocyanin biosyntheses share common precursors in plants. Flavone synthase (FNS) converts naringenin into apigenin in higher plants. Celery is an important edible and medical vegetable crop that contains apigenin in its tissues. However, the effect of high AgFNS gene expression on the apigenin and anthocyanins contents of purple celery remains to be elucidated. In this study, the AgFNS gene was cloned from purple celery ('Nanxuan liuhe purple celery') and overexpressed in this purple celery to determine its influence on anthocyanins and apigenin contents. Results showed that the AgFNS gene was 1068bp, which encodes 355 amino acid residues. Evolution analysis showed that the AgFNS protein belongs to the FSN I type. In AgFNS transgenic celery, the anthocyanins content in petioles was lower than that wild-type celery plants. Apigenin content increased in the petioles of AgFNS transgenic celery. The transcript levels of the AgPAL, AgC4H, AgCHS, and AgCHI genes were up-regulated, whereas those of the AgF3H, AgF3'H, AgDFR, AgANS, and Ag3GT genes were down-regulated in the petioles of AgFNS transgenic plants compared with wild-type celery plants. This work provides basic knowledge about the function of the AgFNS gene in the anthocyanin and apigenin biosyntheses of celery. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Resveratrol, piperine and apigenin differ in their NADPH-oxidase inhibitory and reactive oxygen species-scavenging properties.

    Science.gov (United States)

    Whitehouse, Scott; Chen, Pei-Lin; Greenshields, Anna L; Nightingale, Mat; Hoskin, David W; Bedard, Karen

    2016-11-15

    Many plant-derived chemicals have been studied for their potential benefits in ailments including inflammation, cancer, neurodegeneration, and cardiovascular disease. The health benefits of phytochemicals are often attributed to the targeting of reactive oxygen species (ROS). However, it is not always clear whether these agents act directly as antioxidants to remove ROS, or whether they act indirectly by blocking ROS production by enzymes such as NADPH oxidase (NOX) enzymes, or by influencing the expression of cellular pro- and anti- oxidants. Here we evaluate the pro- and anti-oxidant and NOX-inhibiting qualities of four phytochemicals: celastrol, resveratrol, apigenin, and piperine. This work was done using the H661 cell line expressing little or no NOX, modified H661 cells expressing NOX1 and its subunits, and an EBV-transformed B-lymphoblastoid cell line expressing endogenous NOX2. ROS were measured using Amplex Red and nitroblue tetrazolium assays. In addition, direct ROS scavenging of hydrogen peroxide or superoxide generated were measured using Amplex Red and methyl cypridina luciferin analog (MCLA). Of the four plant-derived compounds evaluated, only celastrol displayed NOX inhibitory activities, while celastrol and resveratrol both displayed ROS scavenging activity. Very little impact on ROS was observed with apigenin, or piperine. The results of this study reveal the differences that exist between cell-free and intracellular pro-oxidant and antioxidant activities of several plant-derived compounds. Copyright © 2016 Elsevier GmbH. All rights reserved.

  11. Effect of apigenin on gap junctional intercellular communication in human Tenon's capsule fibroblasts.

    Science.gov (United States)

    Liu, Shanshan; Wang, Jibing; Zou, Huihui; Huang, Xudong

    2013-06-01

    To investigate the effect of apigenin on gap junctional intercellular communication (GJIC) in human Tenon's capsule fibroblasts (HTFs) and its underlying mechanism. After a 48 h treatment of cultured HTFs with apigenin (80 micromol/L), the GJIC was detected by a scrape-loading/dye transfer technique with Lucifer yellow dye and rhodamine (Rh) dextran. The coupling index represents a quantification of GJIC where a high coupling index is associated with a greater number of cells demonstrating cell-cell communication through gap junction channels. The changes in connexin 43 (Cx43) distribution and the expression of Cx43 at the protein and mRNA levels were statistically compared between the two groups by means of immunocytochemistry, western blotting, and real-time polymerase chain reaction (PCR). The functioning of GJIC in the HTFs was significantly enhanced after 48 hours by apigenin treatment when compared with the control cells. In the apigenin group, the intercellular dye transfer grade was above 9, while this value was only grade 3-4 in the control group. The coupling index was significantly increased up to 9.205+/-0.3621 in the apigenin group, compared with 5.1775+/-0.3177 in the control group (F=279.581, P=0.000). The expression of Cx43 at the protein and mRNA levels was significantly up-regulated in the apigenin group compared with the control group. Apigenin can significantly enhance the function of GJIC in HTFs by up-regulating the expression of Cx43 at both the protein and mRNA levels, suggesting that the enhancement of GJIC in HTFs by apigenin probably acts as an important mechanism underlying the inhibitory effect of apigenin on HTF proliferation.

  12. Apigenin enhances skeletal muscle hypertrophy and myoblast differentiation by regulating Prmt7.

    Science.gov (United States)

    Jang, Young Jin; Son, Hyo Jeong; Choi, Yong Min; Ahn, Jiyun; Jung, Chang Hwa; Ha, Tae Youl

    2017-10-03

    Apigenin, a natural flavone abundant in various plant-derived foods including parsley and celery, has been shown to prevent inflammation and inflammatory diseases. However, the effect of apigenin on skeletal muscle hypertrophy and myogenic differentiation has not previously been elucidated. Here, we investigated the effects of apigenin on quadricep muscle weight and running distance using C57BL/6 mice on an accelerating treadmill. Apigenin stimulated mRNA expression of MHC (myosin heavy chain) 1, MHC2A, and MHC2B in the quadricep muscles of these animals. GPR56 (G protein-coupled receptor 56) and its ligand collagen III were upregulated by apigenin supplementation, together with enhanced PGC-1α, PGC-1α1, PGC-1α4, IGF1, and IGF2 expression. Prmt7 protein expression increased in conjunction with Akt and mTORC1 activation. Apigenin treatment also upregulated FNDC5 (fibronectin type III domain containing 5) mRNA expression and serum irisin levels. Furthermore, apigenin stimulated C2C12 myogenic differentiation and upregulated total MHC, MHC2A, and MHC2B expression. These events were attributable to an increase in Prmt7-p38-myoD expression and Akt and S6K1 phosphorylation. We also observed that Prmt7 regulates both PGC-1α1 and PGC-1α4 expression, resulting in a subsequent increase in GPR56 expression and mTORC1 activation. Taken together, these findings suggest that apigenin supplementation can promote skeletal muscle hypertrophy and myogenic differentiation by regulating the Prmt7-PGC-1α-GPR56 pathway, as well as the Prmt7-p38-myoD pathway, which may contribute toward the prevention of skeletal muscle weakness.

  13. In Vitro and In Vivo Anti-tumoral Effects of the Flavonoid Apigenin in Malignant Mesothelioma

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    Laura Masuelli

    2017-06-01

    Full Text Available Malignant mesothelioma (MM is a tumor arising from mesothelium. MM patients’ survival is poor. The polyphenol 4′,5,7,-trihydroxyflavone Apigenin (API is a “multifunctional drug”. Several studies have demonstrated API anti-tumoral effects. However, little is known on the in vitro and in vivo anti-tumoral effects of API in MM. Thus, we analyzed the in vitro effects of API on cell proliferation, cell cycle regulation, pro-survival signaling pathways, apoptosis, and autophagy of human and mouse MM cells. We evaluated the in vivo anti-tumor activities of API in mice transplanted with MM #40a cells forming ascites. API inhibited in vitro MM cells survival, increased reactive oxygen species intracellular production and induced DNA damage. API activated apoptosis but not autophagy. API-induced apoptosis was sustained by the increase of Bax/Bcl-2 ratio, increase of p53 expression, activation of both caspase 9 and caspase 8, cleavage of PARP-1, and increase of the percentage of cells in subG1 phase. API treatment affected the phosphorylation of ERK1/2, JNK and p38 MAPKs in a cell-type specific manner, inhibited AKT phosphorylation, decreased c-Jun expression and phosphorylation, and inhibited NF-κB nuclear translocation. Intraperitoneal administration of API increased the median survival of C57BL/6 mice intraperitoneally transplanted with #40a cells and reduced the risk of tumor growth. Our findings may have important implications for the design of MM treatment using API.

  14. Propolis Extracted from the Stingless Bee Trigona sirindhornae Inhibited S. mutans Activity In Vitro.

    Science.gov (United States)

    Utispan, Kusumawadee; Chitkul, Bordin; Monthanapisut, Paopanga; Meesuk, Ladda; Pugdee, Kamolparn; Koontongkaew, Sittichai

    The aim of this study was to determine the antimicrobial effects of propolis extracted from an endemic species of stingless bee, T. sirindhornae, on the cariogenic bacterium Streptococcus mutans. Dichloromethane extracts (DME) of propolis (DMEP) were prepared and analysed by reverse-phase high-performance liquid chromatography. The antibacterial growth and antibiofilm formation effects of DMEP on S. mutans were compared with those of apigenin, a commercial propolis product. The effects of DMEP and apigenin on glucosyltransferase (gtf) B expression in S. mutans were investigated using real-time polymerase chain reaction. Chlorhexidine (CHX) was used as a positive control in the experiments. Apigenin, pinocembrin, p-coumaric acid, and caffeic acid were not detected in the propolis extracts. DMEP and apigenin significantly inhibited S. mutans growth (IC50 = 43.5 and 17.36 mg/ml, respectively). DMEP and apigenin also exhibited antiadherence effects on S. mutans as shown by reduced biofilm formation. Furthermore, a significant inhibition in gtfB expression was observed in DMEP and apigenin treated S. mutans. Propolis produced by T. sirindhornae demonstrated antibacterial and antibiofilm effects, and reduced gtfB expression in S. mutans. The antibacterial activities of propolis observed were not due to apigenin, pinocembrin, p-coumaric acid, or caffeic acid.

  15. Synergistic apoptotic effects of apigenin TPGS liposomes and tyroservatide: implications for effective treatment of lung cancer.

    Science.gov (United States)

    Jin, Xin; Yang, Qing; Zhang, Youwen

    2017-01-01

    To develop an alternative treatment for lung cancer, a combination of two potent chemotherapeutic agents - liposomal apigenin and tyroservatide - was developed. The therapeutic potential of this combination was investigated using A549 cells. Apigenin and tocopherol derivative-containing D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) liposomes might improve the delivery of apigenin to tumor cells, both in vitro and in vivo. Importantly, compared to either agent alone, the combination of apigenin TPGS liposomes and tyroservatide exhibited superior cytotoxicity, induced stronger G2 arrest, and suppressed A549 cancer cell invasion at a lower dose. The proapoptotic synergistic effects were also observed in A549 cells using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling, flow cytometry, and Western blot analysis. More importantly, in vivo results showed that the combination of apigenin TPGS liposomes and tyroservatide exhibited tumor-growth inhibitory effects in A549 cell-bearing mice. In conclusion, our study showed that this combination therapy could serve as a promising synergistic therapeutic approach to improve outcomes in patients with lung cancer.

  16. Monoamine Oxidase Inhibitory Constituents of Propolis: Kinetics and Mechanism of Inhibition of Recombinant Human MAO-A and MAO-B

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    Narayan D. Chaurasiya

    2014-11-01

    Full Text Available Propolis is the resinous material that bees gather from leaf buds, flowers and vegetables. Propolis extracts contain constituents with a broad spectra of pharmacological properties and are important ingredients of popular dietary supplements. Propolis extracts were evaluated in vitro for inhibition of recombinant human monoamine oxidase (MAO-A and MAO-B. The dichloromethane extract of propolis showed potent inhibition of human MAO-A and MAO-B. Further fractionation identified the most active fractions as rich in flavonoids. Galangin and apigenin were identified as the principal MAO-inhibitory constituents. Inhibition of MAO-A by galangin was about 36 times more selective than MAO-B, while apigenin selectivity for MAO-A vs. MAO-B was about 1.7 fold. Apigenin inhibited MAO-B significantly more potently than galangin. Galangin and apigenin were further evaluated for kinetic characteristics and the mechanism for the enzymes’ inhibition. Binding of galangin and apigenin with MAO-A and -B was not time-dependent and was reversible, as suggested by enzyme-inhibitor binding and dissociation-dialysis assay. The inhibition kinetics studies suggested that galangin and apigenin inhibited MAO-A and -B by a competitive mechanism. Presence of prominent MAO inhibitory constituents in propolis products suggests their potential for eliciting pharmacological effects that might be useful in depression or other neurological disorders. The results may also have important implications in drug-dietary supplement interactions.

  17. Biopharmaceutics classification and intestinal absorption study of apigenin.

    Science.gov (United States)

    Zhang, Jianjun; Liu, Dapeng; Huang, Yanting; Gao, Yuan; Qian, Shuai

    2012-10-15

    The aim of the study was to characterize the biopharmaceutics classification system (BCS) category of apigenin (AP) using intrinsic dissolution rate (IDR) and rat intestinal permeability, and to investigate the intestinal absorption mechanism of AP in rats. In the present investigation, equilibrium solubility and intrinsic dissolution rate (IDR) of AP were estimated in phosphate buffers. Effective intestinal permeability (P(eff)) of AP was determined using single-pass intestinal perfusion (SPIP) technique in four segments (duodenum, jejunum, ileum and colon) of rat intestine at three concentrations (10, 50 and 100 μg/ml). The aqueous solubility of AP in tested phosphate buffers was very poor with maximum solubility of 2.16 μg/ml at pH 7.5. The IDR of AP was very low with a value of 0.006 mg/min/cm(2). The minimum and maximum P(eff)s determined by SPIP were 0.198×10(-4) and 0.713×10(-4) cm/s at jejunum and duodenum site, respectively. In addition, the concentration-dependent permeability behavior was observed in the duodenum and jejunum, which suggested that AP was transported by both passive and active carrier-mediated saturable mechanism in these two intestinal segments. However, the observed concentration-independent permeability behavior in ileum and colon indicated primarily passive transport mechanism of absorption of AP in the last two intestinal segments. AP was classified as class II drug of the BCS due to its low solubility and high intestinal permeability. AP could be well absorbed in the whole intestine with the main absorption site at duodenum. The absorption of AP in four intestinal segments exhibited different transport mechanisms. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Oral Efficacy of Apigenin against Cutaneous Leishmaniasis: Involvement of Reactive Oxygen Species and Autophagy as a Mechanism of Action.

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    Fernanda Fonseca-Silva

    2016-02-01

    Full Text Available The treatment for leishmaniasis is currently based on pentavalent antimonials and amphotericin B; however, these drugs result in numerous adverse side effects. The lack of affordable therapy has necessitated the urgent development of new drugs that are efficacious, safe, and more accessible to patients. Natural products are a major source for the discovery of new and selective molecules for neglected diseases. In this paper, we evaluated the effect of apigenin on Leishmania amazonensis in vitro and in vivo and described the mechanism of action against intracellular amastigotes of L. amazonensis.Apigenin reduced the infection index in a dose-dependent manner, with IC50 values of 4.3 μM and a selectivity index of 18.2. Apigenin induced ROS production in the L. amazonensis-infected macrophage, and the effects were reversed by NAC and GSH. Additionally, apigenin induced an increase in the number of macrophages autophagosomes after the infection, surrounding the parasitophorous vacuole, suggestive of the involvement of host autophagy probably due to ROS generation induced by apigenin. Furthermore, apigenin treatment was also effective in vivo, demonstrating oral bioavailability and reduced parasitic loads without altering serological toxicity markers.In conclusion, our study suggests that apigenin exhibits leishmanicidal effects against L. amazonensis-infected macrophages. ROS production, as part of the mechanism of action, could occur through the increase in host autophagy and thereby promoting parasite death. Furthermore, our data suggest that apigenin is effective in the treatment of L. amazonensis-infected BALB/c mice by oral administration, without altering serological toxicity markers. The selective in vitro activity of apigenin, together with excellent theoretical predictions of oral availability, clear decreases in parasite load and lesion size, and no observed compromises to the overall health of the infected mice encourage us to supports

  19. Apigenin and Luteolin Attenuate the Breaching of MDA-MB231 Breast Cancer Spheroids Through the Lymph Endothelial Barrier in Vitro

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    Junli Hong

    2018-03-01

    Full Text Available Flavonoids, present in fruits, vegetables and traditional medicinal plants, show anticancer effects in experimental systems and are reportedly non-toxic. This is a favorable property for long term strategies for the attenuation of lymph node metastasis, which may effectively improve the prognostic states in breast cancer. Hence, we studied two flavonoids, apigenin and luteolin exhibiting strong bio-activity in various test systems in cancer research and are readily available on the market. This study has further advanced the mechanistic understanding of breast cancer intravasation through the lymphatic barrier. Apigenin and luteolin were tested in a three-dimensional (3-D assay consisting of MDA-MB231 breast cancer spheroids and immortalized lymph endothelial cell (LEC monolayers. The 3-D model faithfully resembles the intravasation of breast cancer emboli through the lymphatic vasculature. Western blot analysis, intracellular Ca2+ determination, EROD assay and siRNA transfection revealed insights into mechanisms of intravasation as well as the anti-intravasative outcome of flavonoid action. Both flavonoids suppressed pro-intravasative trigger factors in MDA-MB231 breast cancer cells, specifically MMP1 expression and CYP1A1 activity. A pro-intravasative contribution of FAK expression in LECs was established as FAK supported the retraction of the LEC monolayer upon contact with cancer cells thereby enabling them to cross the endothelial barrier. As mechanistic basis, MMP1 caused the phosphorylation (activation of FAK at Tyr397 in LECs. Apigenin and luteolin prevented MMP1-induced FAK activation, but not constitutive FAK phosphorylation. Luteolin, unlike apigenin, inhibited MMP1-induced Ca2+ release. Free intracellular Ca2+ is a central signal amplifier triggering LEC retraction through activation of the mobility protein MLC2, thereby enhancing intravasation. FAK activity and Ca2+ levels did not correlate. This implicates that the pro

  20. Shear rheology and in-vitro release kinetic study of apigenin from lyotropic liquid crystal.

    Science.gov (United States)

    Fan, Jun; Liu, Feng; Wang, Zhongni

    2016-01-30

    Apigenin is a flavonoid compound with diverse pharmacological functions which could develop health benefit products, but its formulation is hampered by its poor water solubility and bioavailability. In this paper, in order to overcome these difficulties, apigenin was encapsulated in LLC formed by polyoxyethylene-10-oleyl ether (Brij 97) and sodium deoxycholate (NaDC) mixtures. The hexagonal liquid crystalline phase (H) and the cubic liquid crystalline phase (C) were found in this system. The shear rheology was used to study the structure change with temperature. It was shown that C3 (Brij 97-NaDC/IPM-PEG400/H2O=36:9:55) was C at low temperature. But above 35.6°C, the matrix of C3 completely transformed to polymer solution. The matrix of H3 was H (Brij 97-NaDC:IPM-PEG 400:H2O=50:9:41) below 50°C, but the structural strength change was obvious. Vitro release experiment was used to study drug release kinetics. It was indicated that apigenin encapsulated in LLC conformed to the concentration diffusion model, and cumulative percentage of apigenin released from C3 and H3 had corresponding relationship with the shear rheology at different temperatures. Copyright © 2015. Published by Elsevier B.V.

  1. RP-HPLC-DAD determination of quercetin, luteolin and apigenin in ...

    African Journals Online (AJOL)

    HPLC methods have been reported to quantify isolated flavonoids or these compounds in complex biological matrices, such as Chinese herbal drugs products from factories. This work was developed to separate quercetin, luteolin and apigenin and to quantify them in extractive solutions from Marchantia covoluta. The main ...

  2. UJI IRITASI DAN AKTIVITAS PERTUMBUHAN RAMBUT TIKUS PUTIH: EFEK SEDIAAN GEL APIGENIN DAN PERASAN HERBA SELEDRI (Apium graveolens L.

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    Emma Sri Kuncari

    2015-05-01

    Full Text Available AbstrakPerasan seledri (Apium graveolens L. biasa dipergunakan untuk memacu pertumbuhan rambut. Salah satu senyawa utama yang terkandung di dalam seledri adalah apigenin. Penelitian ini membahas tentang pengaruh pemakaian gel yang mengandung apigenin dan perasan herba seledri sebagai penumbuh rambut, meliputi uji iritasi dan aktivitas pertumbuhan rambut pada tikus putih jantan galur Spraque-Dawley. Uji iritasi menggunakan metode Kamkaen dan Rao, sedangkan uji aktivitas penumbuh rambut menggunakan metode Hattori-Ogawa dan Suzuki-Hamada. Berdasarkan indeks iritasi primer, semua formulasi gel tidak potensial menyebabkan iritasi pada kulit tikus putih (p>0,05. Gel yang mengandung apigenin dan perasan herba seledri menunjukkan aktivitas lebih baik dalam memacu pertumbuhan rambut (p<0,05 dibandingkan kontrol tanpa perlakuan. Apigenin menunjukkan aktivitas lebih baik (p<0,05 dalam meningkatkan ketebalan rambut dibandingkan kontrol tanpa perlakuan.Namun perlakuan perasan herba seledri tidak nyata (p>0,05 meningkatkan ketebalan rambut. Dapat disimpulkan bahwa gel yang mengandung apigenin dan perasan herba seledri dapat meningkatkan pertumbuhan rambut pada tikus putih dibandingkan kontrol tanpa perlakuan.Kata kunci : seledri, apigenin, gel, iritasi kulit, penumbuh rambutAbstractCelery (Apium graveolens L. juice is widely used for promoting hair growth. One of the main compounds in celery is apigenin. This research discusses about the effect of gel containing apigenin and celery juice application as hair growth in term of skin irritation and its hair growth activity on Spraque-Dawley male mice. The irritation test was Kamkaen and Rao methods, while hair growth activity was HattoriOgawa and Suzuki-Hamada methods. Based on primary index irritation, all of the gel formulations did not signifiantly potential in resulting skin irritation on the mice (p>0,05. Gel containing apigenin andcelery juice showed better activity in promoting hair growth (p<0,05 than

  3. Formulation and characterization of an apigenin-phospholipid phytosome (APLC) for improved solubility, in vivo bioavailability, and antioxidant potential.

    Science.gov (United States)

    Telange, Darshan R; Patil, Arun T; Pethe, Anil M; Fegade, Harshal; Anand, Sridhar; Dave, Vivek S

    2017-10-15

    The apigenin-phospholipid phytosome (APLC) was developed to improve the aqueous solubility, dissolution, in vivo bioavailability, and antioxidant activity of apigenin. The APLC synthesis was guided by a full factorial design strategy, incorporating specific formulation and process variables to deliver an optimized product. The design-optimized formulation was assayed for aqueous solubility, in vitro dissolution, pharmacokinetics, and antioxidant activity. The pharmacological evaluation was carried out by assessing its effects on carbon tetrachloride-induced elevation of liver function marker enzymes in a rat model. The antioxidant activity was assessed by studying its effects on the liver antioxidant marker enzymes. The developed model was validated using the design-optimized levels of formulation and process variables. The physical-chemical characterization confirmed the formation of phytosomes. The optimized formulation demonstrated over 36-fold higher aqueous solubility of apigenin, compared to that of pure apigenin. The formulation also exhibited a significantly higher rate and extent of apigenin release in dissolution studies. The pharmacokinetic analysis revealed a significant enhancement in the oral bioavailability of apigenin from the prepared formulation, compared to pure apigenin. The liver function tests indicated that the prepared phytosome showed a significantly improved restoration of all carbon tetrachloride-elevated rat liver function marker enzymes. The prepared formulation also exhibited antioxidant potential by significantly increasing the levels of glutathione, superoxide dismutase, catalase, and decreasing the levels of lipid peroxidase. The study shows that phospholipid-based phytosome is a promising and viable strategy for improving the delivery of apigenin and similar phytoconstituents with low aqueous solubility. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Involvement of GABAergic pathway in the sedative activity of apigenin, the main flavonoid from Passiflora quadrangularis pericarp

    Directory of Open Access Journals (Sweden)

    Andressa C. Gazola

    Full Text Available Abstract In the current study we showed that oral administration of an aqueous extract of Passiflora quadrangularis L., Passifloraceae, pericarp results in a significant prolongation of the sleep duration in mice evaluated in the ethyl ether-induced hypnosis test which indicates sedative effects. Apigenin, the main flavonoid of the extract, induced a similar sedative response when applied alone, at a dose equivalent to that found in the extract, suggesting that apigenin is mediating the sedative effects of P. quadrangularis extract. In addition, the sedative effect of apigenin was blocked by pretreatment with the benzodiazepine antagonist flumazenil (1 mg/kg, suggesting an interaction of apigenin with gamma-aminobutyric acid type A (GABAA receptors. However, apigenin at concentrations 0.1–50 µM failed to enhance GABA-induced currents through GABAA receptors (α1β2γ2S expressed in Xenopus oocytes. Nevertheless, based on our results, we suggest that the in vivo sedative effect of the P. quadrangularis extract and its main flavonoid apigenin maybe be due to an enhancement of the GABAergic system.

  5. Effects of the vegetable polyphenols epigallocatechin-3-gallate, luteolin, apigenin, myricetin, quercetin, and cyanidin in primary cultures of human retinal pigment epithelial cells.

    Science.gov (United States)

    Chen, Rui; Hollborn, Margrit; Grosche, Antje; Reichenbach, Andreas; Wiedemann, Peter; Bringmann, Andreas; Kohen, Leon

    2014-01-01

    Vegetable polyphenols (bioflavonoids) have been suggested to represent promising drugs for treating cancer and retinal diseases. We compared the effects of various bioflavonoids (epigallocatechin-3-gallate [EGCG], luteolin, apigenin, myricetin, quercetin, and cyanidin) on the physiological properties and viability of cultured human retinal pigment epithelial (RPE) cells. Human RPE cells were obtained from several donors within 48 h of death. Secretion of vascular endothelial growth factor (VEGF) was determined with enzyme-linked immunosorbent assay. Messenger ribonucleic acid levels were determined with real-time reverse transcription polymerase chain reaction. Cellular proliferation was investigated with a bromodeoxyuridine immunoassay, and chemotaxis was examined with a Boyden chamber assay. The number of viable cells was determined by Trypan Blue exclusion. Apoptosis and necrosis rates were determined with a DNA fragmentation enzyme-linked immunosorbent assay. The phosphorylation level of signaling proteins was revealed by western blotting. With the exception of EGCG, all flavonoids tested decreased dose-dependently the RPE cell proliferation, migration, and secretion of VEGF. EGCG inhibited the secretion of VEGF evoked by CoCl2-induced hypoxia. The gene expression of VEGF was reduced by myricetin at low concentrations and elevated at higher concentrations. Luteolin, apigenin, myricetin, and quercetin induced significant decreases in the cell viability at higher concentration, by triggering cellular necrosis. Cyanidin reduced the rate of RPE cell necrosis. Myricetin caused caspase-3 independent RPE cell necrosis mediated by free radical generation and activation of calpain and phospholipase A2. The myricetin- and quercetin-induced RPE cell necrosis was partially inhibited by necrostatin-1, a blocker of programmed necrosis. Most flavonoids tested diminished the phosphorylation levels of extracellular signal-regulated kinases 1/2 and Akt proteins. The intake of

  6. Expression pattern of NMDA receptors reveals antiepileptic potential of apigenin 8-C-glucoside and chlorogenic acid in pilocarpine induced epileptic mice.

    Science.gov (United States)

    Aseervatham, G Smilin Bell; Suryakala, U; Doulethunisha; Sundaram, S; Bose, P Chandra; Sivasudha, T

    2016-08-01

    The present study was aimed to evaluate the effect of apigenin 8-C-glucoside (Vitexin) and chlorogenic acid on epileptic mice induced by pilocarpine and explored its possible mechanisms. Intraperitonial administration of pilocarpine (85mg/kg) induced seizure in mice was assessed by behavior observations, which is significantly (p>0.05) reduced by apigenin 8-C-glucoside (AP8CG) (10mg/kg) and chlorogenic acid (CA) (5mg/kg), similar to diazepam. Seizure was accompanied by an imbalance in the levels of Gamma-aminobutyric acid (GABA) and glutamate in the pilocarpine administered group. Moreover, convulsion along with reduced acetylcholinesterase, increased monoamine oxidase and oxidative stress was observed in epileptic mice brain. AP8CG and CA significantly restored back to normal levels even at lower doses. Further, increased lipid peroxidation and nitrite content was also significantly attenuated by AP8CG and CA. However, CA was found to be more effective when compared to AP8CG. In addition, the mRNA expression of N-methyl-d-aspartate receptor (NMDAR), mGluR1 and mGlu5 was significantly (P≤0.05) inhibited by AP8CG and CA in a lower dose. The mRNA expression of GRIK1 did not differ significantly in any of the group and showed a similar pattern of expression. Our result shows that AP8CG and CA selectively inhibit NMDAR, mGluR1 and mGlu5 expression. Modification in the provoked NMDAR calcium response coupled with neuronal death. Hence, these findings underline that the polyphenolics, AP8CG and CA have exerted antiepileptic and neuroprotective activity by suppressing glutamate receptors. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  7. In vivo radioprotective effect of curcumin, taurine, apigenin and kampferol on DNA damage in mouse

    International Nuclear Information System (INIS)

    Jayakumar, S.; Bhilwade, H.N.; Chaubey, R.C.

    2012-01-01

    Ionizing radiation is known to produce oxidative stress through the generation of ROS leading to a variety of DNA lesions. However, the most dangerous DNA lesions which are responsible for the origin of lethal effects, mutagenesis, genomic instability and carcinogenesis are the DSBs. During recent years efforts are being made to identify phytochemicals or other naturally occurring compounds which can reduce the harmful effect of radiation during accidental exposure or prevent normal tissue injury during radiotherapy. In present study, we have investigated the protective role of curcumin, taurine, apigenin and kaempferol against radiation-induced oxidative damage in mice. Groups of mice were fed 1 % of curcumin in diet for three weeks. Similarly other groups of mice were injected i.p. with 50 mg/kg body weight of taurine for five consecutive days. Other four groups of mice were injected i.p. with apigenin (10.8 mg/kg BW and 21.6 mg/kg BW), kaempferol (14.3 mg/kg BW and 28.6 mg/kg BW). After the completion of the treatment mice pre-treated with curcumin, taurine, apigenin and kaempferol were exposed to 2 or 3 Gy of gamma rays. Immediately after irradiation, alkaline comet assay was performed using standard procedures. Twenty four post radiation exposure mice were sacrificed for micronucleus test

  8. Modulation of thyroidal radioiodide uptake by oncological pipeline inhibitors and Apigenin

    Science.gov (United States)

    Lakshmanan, Aparna; Scarberry, Daniel; Green, Jill A.; Zhang, Xiaoli; Selmi-Ruby, Samia; Jhiang, Sissy M.

    2015-01-01

    Targeted radioiodine therapy for thyroid cancer is based on selective stimulation of Na+/I− Symporter (NIS)-mediated radioactive iodide uptake (RAIU) in thyroid cells by thyrotropin. Patients with advanced thyroid cancer do not benefit from radioiodine therapy due to reduced or absent NIS expression. To identify inhibitors that can be readily translated into clinical care, we examined oncological pipeline inhibitors targeting Akt, MEK, PI3K, Hsp90 or BRAF in their ability to increase RAIU in thyroid cells expressing BRAFV600E or RET/PTC3 oncogene. Our data showed that (1) PI3K inhibitor GDC-0941 outperformed other inhibitors in RAIU increase mainly by decreasing iodide efflux rate to a great extent; (2) RAIU increase by all inhibitors was extensively reduced by TGF-β, a cytokine secreted in the invasive fronts of thyroid cancers; (3) RAIU reduction by TGF-β was mainly mediated by NIS reduction and could be reversed by Apigenin, a plant-derived flavonoid; and (4) In the presence of TGF-β, GDC-0941 with Apigenin co-treatment had the highest RAIU level in both BRAFV600E expressing cells and RET/PTC3 expressing cells. Taken together, Apigenin may serve as a dietary supplement along with small molecule inhibitors to improve radioiodine therapeutic efficacy on invasive tumor margins thereby minimizing future metastatic events. PMID:26397139

  9. The flavonoid compound apigenin prevents colonic inflammation and motor dysfunctions associated with high fat diet-induced obesity.

    Science.gov (United States)

    Gentile, Daniela; Fornai, Matteo; Colucci, Rocchina; Pellegrini, Carolina; Tirotta, Erika; Benvenuti, Laura; Segnani, Cristina; Ippolito, Chiara; Duranti, Emiliano; Virdis, Agostino; Carpi, Sara; Nieri, Paola; Németh, Zoltán H; Pistelli, Laura; Bernardini, Nunzia; Blandizzi, Corrado; Antonioli, Luca

    2018-01-01

    Apigenin can exert beneficial actions in the prevention of obesity. However, its putative action on obesity-associated bowel motor dysfunctions is unknown. This study examined the effects of apigenin on colonic inflammatory and motor abnormalities in a mouse model of diet-induced obesity. Male C57BL/6J mice were fed with standard diet (SD) or high-fat diet (HFD). SD or HFD mice were treated with apigenin (10 mg/Kg/day). After 8 weeks, body and epididymal fat weight, as well as cholesterol, triglycerides and glucose levels were evaluated. Malondialdehyde (MDA), IL-1β and IL-6 levels, and let-7f expression were also examined. Colonic infiltration by eosinophils, as well as substance P (SP) and inducible nitric oxide synthase (iNOS) expressions were evaluated. Motor responses elicited under blockade of NOS and tachykininergic contractions were recorded in vitro from colonic longitudinal muscle preparations. When compared to SD mice, HFD animals displayed increased body weight, epididymal fat weight and metabolic indexes. HFD mice showed increments in colonic MDA, IL-1β and IL-6 levels, as well as a decrease in let-7f expression in both colonic and epididymal tissues. HFD mice displayed an increase in colonic eosinophil infiltration. Immunohistochemistry revealed an increase in SP and iNOS expression in myenteric ganglia of HFD mice. In preparations from HFD mice, electrically evoked contractions upon NOS blockade or mediated by tachykininergic stimulation were enhanced. In HFD mice, Apigenin counteracted the increase in body and epididymal fat weight, as well as the alterations of metabolic indexes. Apigenin reduced also MDA, IL-1β and IL-6 colonic levels as well as eosinophil infiltration, SP and iNOS expression, along with a normalization of electrically evoked tachykininergic and nitrergic contractions. In addition, apigenin normalized let-7f expression in epididymal fat tissues, but not in colonic specimens. Apigenin prevents systemic metabolic alterations

  10. Correlating In Vitro Target-Oriented Screening and Docking: Inhibition of Matrix Metalloproteinases Activities by Flavonoids.

    Science.gov (United States)

    Crascì, Lucia; Basile, Livia; Panico, Annamaria; Puglia, Carmelo; Bonina, Francesco P; Basile, Pierluigi Maria; Rizza, Luisa; Guccione, Salvatore

    2017-07-01

    Metalloproteases are a family of zinc-containing endopeptidases involved in a variety of pathological disorders. The use of flavonoid derivatives as potential metalloprotease inhibitors has recently increased.Particular plants growing in Sicily are an excellent yielder of the flavonoids luteolin, apigenin, and their respective glycoside derivatives (7-O-rutinoside, 7-O-glucoside, and 7-O-glucuronide).The inhibitory activity of luteolin, apigenin, and their respective glycoside derivatives on the metalloproteases MMP-1, MMP-3, MMP-13, MMP-8, and MMP-9 was assessed and rationalized correlating in vitro target-oriented screening and in silico docking.The flavones apigenin, luteolin, and their respective glucosides have good ability to interact with metalloproteases and can also be lead compounds for further development. Glycones are more active on MMP-1, -3, -8, and -13 than MMP-9. Collagenases MMP-1, MMP-8, and MMP-13 are inhibited by compounds having rutinoside glycones. Apigenin and luteolin are inactive on MMP-1, -3, and -8, which can be interpreted as a better selectivity for both -9 and -13 peptidases. The more active compounds are apigenin-7-O-rutinoside on MMP-1 and luteolin-7-O-rutinoside on MMP-3. The lowest IC 50 values were also found for apigenin-7-O-glucuronide, apigenin-7-O-rutinoside, and luteolin-7-O-glucuronide. The glycoside moiety might allow for a better anchoring to the active site of MMP-1, -3, -8, -9, and -13. Overall, the in silico data are substantially in agreement with the in vitro ones (fluorimetric assay). Georg Thieme Verlag KG Stuttgart · New York.

  11. Novel apigenin-loaded sodium hyaluronate nano-assemblies for targeting tumor cells.

    Science.gov (United States)

    Zhao, Ting; He, Yue; Chen, Huali; Bai, Yan; Hu, Wenjing; Zhang, Liangke

    2017-12-01

    We aimed to construct a novel nano-assembly carrying apigenin (APG), a hydrophobic drug, and to evaluate its in vitro targeting ability for A549 cells overexpressing CD44 receptors. The apigenin-loaded sodium hyaluronate nano-assemblies (APG/SH-NAs) were assembled by multiple non-covalent interactions between sodium hyaluronate (SH) and APG. The prepared APG/SH-NAs exhibited a small average size and narrow particle size distribution. In addition, satisfactory encapsulation efficiency and drug loading were obtained. The drug release curves indicated that APG/SH-NAs achieved a sustainable drug-release effect due to the presence of hydrophilic materials. The in vitro cytotoxicity of APG/SH-NAs against A549 cells and HepG2 cells was evaluated, and the results indicated that the prepared APG/SH-NA showed higher cytotoxicity compared to apigenin suspensions. When CD44 receptors on the surface of A549 cells were blocked by the addition of excess SH, the cytotoxicity of APG/SH-NA was significantly reduced. However, similar phenomena were not observed in HepG2 cells with relatively low CD44 receptor expression. The resulting APG/SH-NAs could efficiently facilitate the internalization of APG into A549 cells, which might be due to their high affinity for CD44 receptors. Moreover, the apoptotic rate of APG/SH-NAs through receptor-mediated endocytosis mechanism was higher than that of the other groups in A549 cells. Thus, such nano-assemblies were considered to be an effective transport system with excellent affinity for CD44 receptors to allow the SH-mediated targeted delivery of APG. Copyright © 2017. Published by Elsevier Ltd.

  12. Anti-degenerative effect of Apigenin, Luteolin and Quercetin on human keratinocyte and chondrocyte cultures: SAR evaluation.

    Science.gov (United States)

    Crascì, Lucia; Cardile, Venera; Longhitano, Giusy; Nanfitò, Francesco; Panico, Annamaria

    2017-11-06

    Background Inflammation is a dynamic process that occur on vascularized tissue in response to different stimuli causing cell injury and tissue degeneration. Reactive oxygen and nitrogen species (ROS and RNS) and advanced glycation end products (AGEs) have a key mediatory role in the development and progression of degenerative tissue process. The bioflavonoids possess a broad-spectrum of pharmacological activities. Their capability is related to their chemical structure. Methods In this study we evaluated and compare antioxidant, anti-glycative and anti-degenerative actions of two flavones apigenin and luteolin and a flavonol quercetin, in function of their hydroxyl groups arrangement. Moreover we assay, on NCTC 2544 and chondrocytes cultures, the flavonoids capacity to modulate NO and glycosamminoglycans levels, index of antidegenerative capacity. Results All tested flavonoids act as free radicals scavengers (ROO • and NO • ) and advanced glycation end products inhibitors, in agreement with their BDE, IP and molecular planarity. Quercetin showed a high ORAC value (2.70±0.12 ORAC Units), according to a low BDE (74.54 Kcal/mol) and IP (174.44 Kcal/mol) values. Luteolin is the most active compound in the NO (48.19±0.18%) and AGEs (60.06±0.52%) inhibition, in function of a low torsion angle (16.3°) between the 3-OH moiety and C'6 carbon atom. Conclusion All tested flavonoids posses a protective role on degenerative tissue events. They acts in different manner depending on the functional groups, the biological substrate and the concentration used. In any case, it can be considered a suitable product preventing a degenerative processes. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Apigenin-induced nitric oxide production involves calcium-activated potassium channels and is responsible for antiangiogenic effects.

    Science.gov (United States)

    Erdogan, A; Most, A K; Wienecke, B; Fehsecke, A; Leckband, C; Voss, R; Grebe, M T; Tillmanns, H; Schaefer, C A; Kuhlmann, C R W

    2007-08-01

    The dietary flavonoid apigenin (Api) has been demonstrated to exert multiple beneficial effects upon the vascular endothelium. The aim of this study was to examine whether Ca(2+)-activated K(+) channels (K(Ca)) are involved in endothelial nitric oxide (NO) production and antiangiogenic effects. Endothelial NO generation was monitored using a cyclic guanosine monophosphate radioimmunoassay. K(Ca) activity and changes of the intracellular Ca(2+) concentration [Ca(2+)](i) were analyzed using the fluorescent dyes bis-barbituric acid oxonol, potassium-binding benzofuran isophthalate, and fluo-3. The endothelial angiogenic parameters measured were cell proliferation, [(3)H]-thymidine incorporation, and cell migration (scratch assay). Akt phosphorylation was examined using immunohistochemistry. Api caused a concentration-dependent increase in cyclic guanosine monophosphate levels, with a maximum effect at a concentration of 1 mum. Api-induced hyperpolarization was blocked by the small and large conductance K(Ca) inhibitors apamin and iberiotoxin, respectively. Furthermore, apamin and iberiotoxin blocked the late, long-lasting plateau phase of the Api-induced biphasic increase of [Ca(2+)](i). Inhibition of Ca(2+) signaling and the K(Ca) blockade both blocked NO production. Prevention of all three (NO, Ca(2+), and K(Ca) signaling) reversed the antiangiogenic effects of Api under both basal and basic fibroblast growth factor-induced culture conditions. Basic fibroblast growth factor-induced Akt phosphorylation was also reduced by Api. Based on our experimental results we propose the following signaling cascade for the effects of Api on endothelial cell signaling. Api activates small and large conductance K(Ca), leading to a hyperpolarization that is followed by a Ca(2+) influx. The increase of [Ca(2+)](i) is responsible for an increased NO production that mediates the antiangiogenic effects of Api via Akt dephosphorylation.

  14. In Vitro and In Vivo Anti-tumoral Effects of the Flavonoid Apigenin in Malignant Mesothelioma

    OpenAIRE

    Laura Masuelli; Monica Benvenuto; Rosanna Mattera; Enrica Di Stefano; Erika Zago; Gloria Taffera; Ilaria Tresoldi; Maria Gabriella Giganti; Giovanni Vanni Frajese; Ginevra Berardi; Andrea Modesti; Andrea Modesti; Roberto Bei; Roberto Bei

    2017-01-01

    Malignant mesothelioma (MM) is a tumor arising from mesothelium. MM patients’ survival is poor. The polyphenol 4′,5,7,-trihydroxyflavone Apigenin (API) is a “multifunctional drug”. Several studies have demonstrated API anti-tumoral effects. However, little is known on the in vitro and in vivo anti-tumoral effects of API in MM. Thus, we analyzed the in vitro effects of API on cell proliferation, cell cycle regulation, pro-survival signaling pathways, apoptosis, and autophagy of human and mouse...

  15. EVALUASI, UJI STABILITAS FISIK DAN SINERESIS SEDIAAN GEL YANG MENGANDUNG MINOKSIDIL, APIGENIN DAN PERASAN HERBA SELEDRI (Apium graveolens L.

    Directory of Open Access Journals (Sweden)

    Emma Sri Kuncari

    2015-01-01

    Full Text Available AbstractMinoxidil, apigenin and celery are believed to have the same bioactivity as a vasodilator that can widen blood vessels. This study discusses about the gel formulation in the scope of evaluation of gel preparation, using carbomer as a gelling agent each containing minoxidil, apigenin and celery juice. The method used in gel evaluation were organoleptic observation, homogeneity, pH, consistency and viscosity; physical stability at 40±2 °C, 28±2 °C, 4±2 °C and syneresis. Based on the result, all gel formulations showed their consistency and viscosity were higher after 8 weeks of storage at room temperature. The rheogram of three gel formulations in term of flow properties remain unchanged after 8 weeks of storage. It was indicated that the flow properties of gel formulation was pseudoplastis tixotropic. The gel containing minoxidil, apigenin and celery juice showed good physical stability at 28±2 °C and 40±2 °C, but less stable at 4±2 °C after 14 weeks of storage. The highest number of syneresis was found in a gel containing celery juice.Keywords : Celery, Apigenin, Gel, StabilityAbstrakMinoksidil, apigenin dan seledri memiliki aktivitas biologi yang sama sebagai vasodilator yang dapat memperlebar pembuluh darah. Penelitian ini sebagai evaluasi sediaan gel, menggunakan karbomer sebagai gelling agentyang mengandung masing-masing minoksidil, apigenin dan perasan herba seledri. Metode yang digunakan dalam evaluasi gel adalah pengamatan organoleptis, homogenitas, pH, konsistensi dan viskositas; stabilitas fisik pada suhu 40±2 °C, 28±2 °C, 4±2 °C dan sineresis. Berdasarkan hasil penelitian, ketiga formula gel menunjukkan konsistensi dan viskositas yang lebih tinggi setelah 8  minggu  penyimpanan  pada  temperatur  ruang.  Hasil  rheogram  dari  ketiga  formula gel  menunjukkan  sifat  alir  yang  tetap  tidak  berubah  setelah  8  minggu  penyimpanan, yaitu pseudoplastis tiksotropik. Gel yang mengandung

  16. A comparative DFT study on the antioxidant activity of apigenin and scutellarein flavonoid compounds

    Science.gov (United States)

    Sadasivam, K.; Kumaresan, R.

    2011-03-01

    The potent antioxidant activity of flavonoids relevant to their ability to scavenge reactive oxygen species is the most important function of flavonoids. Density functional theory calculations were explored to investigate the antioxidant activity of flavonoid compounds such as apigenin and scutellarein. The biological characteristics are dependent on electronic parameters, describing the charge distribution on the rings of the flavonoid molecules. The computation of structural and various molecular descriptors such as polarizability, dipole moment, energy gap, homolytic O-H bond dissociation enthalpies (BDEs), ionization potential (IP), electron affinity, hardness, softness, electronegativity, electrophilic index and density plot of molecular orbital for neutral as well as radical species were carried out and studied. The B3LYP/6-311G(d,p) basis set was adopted for all the computations. This computation reveals that scutellarein exhibits higher degree of antioxidant activity than apigenin. Their dipole moment and polarizability analysis show that both the compounds are polar in nature and have the capacity to polarize other atoms.

  17. Total synthesis of 8-(6″-umbelliferyl)-apigenin and its analogs as anti-diabetic reagents.

    Science.gov (United States)

    Pan, Guojun; Zhao, Lianbo; Xiao, Na; Yang, Ke; Ma, Yantao; Zhao, Xia; Fan, Zhenchuan; Zhang, Yongmin; Yao, Qingwei; Lu, Kui; Yu, Peng

    2016-10-21

    The naturally occurring flavone 8-(6″-umbelliferyl)apigenin, a hybrid structure of apigenin and coumarin, as well as seven of its analogues were synthesized for the first time by using iodination and Suzuki coupling reactions as key steps. The synthesis of 8-(6″-umbelliferyl)-apigenin was achieved in seven linear steps from the commercially available 1-(2,4,6-trihydroxyphenyl)ethan-1-one and 7-hydroxyl coumarine with 31% overall yield. Effects of these compounds on glucose disposal were investigated in adipocytes. All of the flavonoid and coumarin hydrids were found to have better bioactivities than their corresponding flavonoid cores. The most potent compound 15 (10 μΜ) could promote glucose consumption by 57% which exhibited similar effect as the positive control metformin at 1 mM. Moreover, fluorescence microscopy showed that four 8-(6″-umbelliferyl)apigenin analogues 2, 15, 30 and 31 could promote the 2-NBDG uptake into 3T3-L1 cells, which consist with those observed in the regulation of glucose. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  18. Bioassay-guided isolation of apigenin with GABA-benzodiazepine activity from Tanacetum parthenium

    DEFF Research Database (Denmark)

    Jäger, Anna Katharina; Krydsfeldt, Katrine; Rasmussen, Hasse Bonde

    2009-01-01

    was fractionated by VLC on silica and preparative C18 HPLC. Each step was monitored with the GABA(A)-benzodiazepine bioassay. The fractionation led to the isolation of apigenin, which may be responsible for CNS-effects of T. parthenium extracts. Copyright (c) 2009 John Wiley & Sons, Ltd....

  19. Induction of NRF2-mediated gene expression by dietary phytochemical flavones apigenin and luteolin.

    Science.gov (United States)

    Paredes-Gonzalez, Ximena; Fuentes, Francisco; Jeffery, Sundrina; Saw, Constance Lay-Lay; Shu, Limin; Su, Zheng-Yuan; Kong, Ah-Ng Tony

    2015-10-01

    Apigenin (API) and luteolin (LUT) have been used as therapeutic agents in folk medicine for thousands of years. These compounds exert a variety of biological activities, including anticancer, antioxidant and antiinflammatory activities. This study investigated whether API and LUT could activate Nrf2-antioxidant response element (ARE)-mediated gene expression and induce antiinflammatory activities in human hepatoma HepG2 cells. The compounds did not exhibit any substantial toxicity at low doses (1.56-6.25 µm). The induction of ARE activity was assessed in HepG2-C8 cells after treatment with low doses of API and LUT for 6 and 12 h. It was found that the induction of ARE activity by these compounds at the higher doses was comparable to the effects of the positive control, SFN at a dose of 6.25 µm. Exposure to the PI3K inhibitor LY294002 abolished ARE activation by both API and LUT, whereas the ERK-1/2 inhibitor PD98059 only decreased ARE activity induced by API. Both compounds significantly increased the endogenous mRNA and protein levels of Nrf2 and Nrf2 target genes with important effects on heme oxygenase-1 (HO-1) expression. API and LUT significantly and dose-dependently decreased the production of nitric oxide (NO), nitric oxide synthase (iNOS) and cytosolic phospholipase A2 (cPLA2), which were induced by the treatment of HepG2 cells with 1 µg/ml of lipopolysaccharide (LPS) for 24 h. The results indicate that API and LUT significantly activate the PI3K/Nrf2/ARE system, and this activation may be responsible for their antiinflammatory effects, as demonstrated by the suppression of LPS-induced NO, iNOS and cPLA2. Copyright © 2015 John Wiley & Sons, Ltd.

  20. Discovery of xanthine oxidase inhibitors and/or α-glucosidase inhibitors by carboxyalkyl derivatization based on the flavonoid of apigenin.

    Science.gov (United States)

    Su, Zhuo-Ran; Fan, Shi-Yong; Shi, Wei-Guo; Zhong, Bo-Hua

    2015-07-15

    Three series of apigenin derivatives have been prepared by coupling the carboxyl alkyl group to 4'-, 5- or 7-hydroxyl groups of apigenin respectively. Preliminary biological evaluation in vitro revealed that xanthine oxidase inhibitory activity was improved by modifications at 4'-position and decreased by similar modifications at 5-, 7-positions while α-glucosidase inhibitory activity was maintained by modifications at 5-, 7-positions but lost by modifications at 4'-position. Administration (ip) of 7e markedly lowered serum uric acid levels in potassium oxonate induced hyperuricemic mouse model and administration (p.o.) of 11d or 11e effectively suppressed the elevation of serum glucose in the oral sucrose tolerance test in mice, while apigenin were not significantly effective in both tests. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Plant growth inhibiting flavonoids in exudate of Cistus ladanifer and in associated soils.

    Science.gov (United States)

    Chaves, N; Sosa, T; Escudero, J C

    2001-03-01

    Of the aglycone flavonoids identified in the exudate of cistus ladanifer, two, the flavone apigenin-4'-(O)-methyl and the flavonol kaempferol-3,7-di(O)-methyl inhibit development of the seedlings of Rumex crispus at 0.5 and 1 mM. Additive effects were observed between the major flavonols of the exudate kaempferol-3-(O)-methyl and kaempferol-3,7-di-(O)-methyl in inhibiting the size of the cotyledons and delaying the germination and cotyledon emergence. The presence of apigenin-4'-(O)-methyl, kaempferol-3,7-di-(O)-methyl, and kaempferol-3-(O)-methyl was detected in the soils associated with C. ladanifer during the summer and autumn months. That these compounds are present in the soil and are not restricted to the leaves provides support for the hypothesis that C. ladanifer has allelopathic potential.

  2. Effect of parsley (Petroselinum crispum) intake on urinary apigenin excretion, blood antioxidant enzymes and biomarkers for oxidative stress in human subjects

    DEFF Research Database (Denmark)

    Nielsen, S. E.; Young, J.F.; Daneshvar, B.

    1999-01-01

    with parsley and 0-112.27 mu g/MJ per 24h on the basic diet (P fraction of apigenin intake excreted in the urine was 0.58 (sE 0.16) % during parsley intervention. Erythrocyte glutathione reductase (EC 1.6.4.1; GR) and superoxide dismutase (EC 1.15.1.1; SOD) activities increased during intervention...

  3. Simultaneous determination of oleanolic acid, ursolic acid, quercetin and apigenin in Swertia mussotii Franch by capillary zone electrophoresis with running buffer modifier.

    Science.gov (United States)

    Gao, Ruibin; Wang, Litao; Yang, Yan; Ni, Jingman; Zhao, Liang; Dong, Shuqing; Guo, Mei

    2015-03-01

    The method of capillary zone electrophoresis (CZE) with direct UV detection was developed for the determination of oleanolic acid, ursolic acid, quercetin and apigenin. and then for the first time successfully applied to the analysis of four analytes in Swertia mussotii Franch and its preparations. Various factors affecting the CZE procedure were investigated and optimized, and the optimal conditions were: 50 × 10(-3) mol/L borate-phosphate buffer (pH 9.5) with 5.0 × 10(-3) mol/L β-cyclodextrin, 15 kV separation voltage, 20 °C column temperature, 250 nm detection wavelength and 5 s electrokinetic injection time (voltage 20 psi). Under the conditions, oleanolic acid, ursolic acid, quercetin and apigenin could be determined within the test ranges with a good correlation coefficient (r(2) > 0.9991). The limits of detection for conditions, oleanolic acid, ursolic acid, quercetin and apigenin were 0.3415, 0.2003, 0.0062 and 0.2538 µg/mL, respectively, and the intra- and inter-day relative standard deviations were no more than 4.72%. This procedure provided a convenient, sensitive and accurate method for simultaneous determination of oleanolic acid, ursolic acid, quercetin and apigenin in S. mussotii Franch. Copyright © 2014 John Wiley & Sons, Ltd.

  4. Apigenin Isolated from the Medicinal Plant Elsholtzia rugulosa Prevents β-Amyloid 25–35-Induces Toxicity in Rat Cerebral Microvascular Endothelial Cells

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    Qingshan Liu

    2011-05-01

    Full Text Available Endothelial cells of cerebral capillaries forming the blood-brain barrier play an important role in the pathogenesis and therapy of Alzheimer’s disease. Amyloid-β peptides are key pathological elements in the development of this disease. Apigenin (4’,5,7-tetrahydroxyflavone is a plant flavonoid and pharmacologically active agent that can be isolated from several plant species. In the present study, effects of apigenin obtained from the medicinal plant Elsholtzia rugulosa (Labiatae on primary cultured rat cerebral microvascular endothelial cells (CMECs mediated by amyloid-β peptide 25–35 (Aβ25–35 were examined. Aβ25–35 showed toxic effects on CMECs, involving reduction of cell viability, release of lactate dehydrogenase (LDH, increase of nuclear condensation, over-production of intracellular reactive oxygen species (ROS, decrease of superoxide dismutase (SOD activity, and breakage of the barrier integrity and function. Based on this model, we demonstrated that apigenin from the medicinal plant Elsholtzia rugulosa protected cultured rat CMECs by increasing cell viability, reducing LDH release, relieving nuclear condensation, alleviating intracellular ROS generation, increasing SOD activity, and strengthening the barrier integrity through the preservation of transendothelial electrical resistance, permeability property and characteristic enzymatic activity after being exposed to Aβ25–35. In conclusion, apigenin isolated from Elsholtzia rugulosa has the ability to protect rat CMECs against Aβ25–35-induced toxicity.

  5. Curcumin inhibited HGF-induced EMT and angiogenesis through regulating c-Met dependent PI3K/Akt/mTOR signaling pathways in lung cancer

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    Demin Jiao

    2016-01-01

    Full Text Available The epithelial-mesenchymal transition (EMT and angiogenesis have emerged as two pivotal events in cancer progression. Curcumin has been extensively studied in preclinical models and clinical trials of cancer prevention due to its favorable toxicity profile. However, the possible involvement of curcumin in the EMT and angiogenesis in lung cancer remains unclear. This study found that curcumin inhibited hepatocyte growth factor (HGF-induced migration and EMT-related morphological changes in A549 and PC-9 cells. Moreover, pretreatment with curcumin blocked HGF-induced c-Met phosphorylation and downstream activation of Akt, mTOR, and S6. These effects mimicked that of c-Met inhibitor SU11274 or PI3 kinase inhibitor LY294002 or mTOR inhibitor rapamycin treatment. c-Met gene overexpression analysis further demonstrated that curcumin suppressed lung cancer cell EMT by inhibiting c-Met/Akt/mTOR signaling pathways. In human umbilical vein endothelial cells (HUVECs, we found that curcumin also significantly inhibited PI3K/Akt/mTOR signaling and induced apoptosis and reduced migration and tube formation of HGF-treated HUVEC. Finally, in the experimental mouse model, we showed that curcumin inhibited HGF-stimulated tumor growth and induced an increase in E-cadherin expression and a decrease in vimentin, CD34, and vascular endothelial growth factor (VEGF expression. Collectively, these findings indicated that curcumin could inhibit HGF-promoted EMT and angiogenesis by targeting c-Met and blocking PI3K/Akt/mTOR pathways.

  6. Fabrication, in-vitro characterization, and enhanced in-vivo evaluation of carbopol-based nanoemulsion gel of apigenin for UV-induced skin carcinoma.

    Science.gov (United States)

    Jangdey, Manmohan S; Gupta, Anshita; Saraf, Swarnlata

    2017-11-01

    The aim of this study was to develop a potential novel formulation of carbopol-based nanoemulsion gel containing apigenin using tamarind gum emulsifier which was having the smallest droplet size, the highest drug content, and a good physical stability for Skin delivery. Apigenin loaded nanoemulsion was prepared by high speed homogenization method and they were characterized with respect to morphology, zeta potential, differential scanning calorimeter study, and penetration studies. In-vitro release studies and skin permeation of apigenin loaded nanoemulsion by goat abdominal skin was determined using Franz diffusion cell and confocal laser scanning microscope (CLSM). The cytotoxicity of the reported formulation was evaluated in HaCaT Cells (A) and A431 cells (B) by MTT assay. The nanoemulsion formulation showed droplet size, polydispersity index, and zeta potential of 183.31 nm, 0.532, and 31.9 mV, respectively. The nanoemulsions were characterized by TEM demonstrated spherical droplets and FTIR to ensure the compatibility among its ingredients. CLSM showed uniform fluorescence intensity across the entire depth of skin in nanocarriers treatment, indicating high penetrability of nanoemulsion gel through goatskin. The nanoemulsion gel showed toxicity on melanoma (A341) in a concentration range of 0.4-2.0 mg/ml, but less toxicity toward HaCaT cells. The carbopol-based nanoemulsion gel formulation of apigenin possesses better penetrability across goatskin as compared to marketed formulation. Hence, the study postulates that the novel nanoemulsion gel of apigenin can be proved fruitful for the treatment of skin cancer in near future.

  7. Luteolin, a flavonoid, inhibits AP-1 activation by basophils

    International Nuclear Information System (INIS)

    Hirano, Toru; Higa, Shinji; Arimitsu, Junsuke; Naka, Tetsuji; Ogata, Atsushi; Shima, Yoshihito; Fujimoto, Minoru; Yamadori, Tomoki; Ohkawara, Tomoharu; Kuwabara, Yusuke; Kawai, Mari; Matsuda, Hisashi; Yoshikawa, Masayuki; Maezaki, Naoyoshi; Tanaka, Tetsuaki; Kawase, Ichiro; Tanaka, Toshio

    2006-01-01

    Flavonoids including luteolin, apigenin, and fisetin are inhibitors of IL-4 synthesis and CD40 ligand expression by basophils. This study was done to search for compounds with greater inhibitory activity of IL-4 expression and to clarify the molecular mechanisms through which flavonoids inhibit their expression. Of the 37 flavonoids and related compounds examined, ayanin, luteolin, and apigenin were the strongest inhibitors of IL-4 production by purified basophils in response to anti-IgE antibody plus IL-3. Luteolin did not suppress Syk or Lyn phosphorylation in basophils, nor did suppress p54/46 SAPK/JNK, p38 MAPK, and p44/42 MAPK activation by a basophilic cell line, KU812 cells, stimulated with A23187 and PMA. However, luteolin did inhibit phosphorylation of c-Jun and DNA binding activity of AP-1 in nuclear lysates from stimulated KU812 cells. These results provide a fundamental structure of flavonoids for IL-4 inhibition and demonstrate a novel action of flavonoids that suppresses the activation of AP-1

  8. Simultaneous Determination and Pharmacokinetic Study of Quercetin, Luteolin, and Apigenin in Rat Plasma after Oral Administration of Matricaria chamomilla L. Extract by HPLC-UV

    Directory of Open Access Journals (Sweden)

    Xiaoxv Dong

    2017-01-01

    Full Text Available A simple and sensitive HPLC-UV method has been developed for the simultaneous determination of quercetin, luteolin, and apigenin in rat plasma after oral administration of Matricaria chamomilla L. extract. The flow rate was set at 1.0 ml/min and the detection wavelength was kept at 350 nm. The calibration curves were linear in the range of 0.11–11.36 μg/ml for quercetin, 0.11–11.20 μg/ml for luteolin, and 0.11–10.60 μg/ml for apigenin, respectively. The intraday and interday precisions (RSD were less than 8.32 and 8.81%, respectively. The lower limits of quantification (LLOQ of the three compounds were 0.11 μg/ml. The mean recoveries for quercetin, luteolin, and apigenin were 99.11, 95.62, and 95.21%, respectively. Stability studies demonstrated that the three compounds were stable in the preparation and analytical process. The maximum plasma concentration (Cmax was 0.29 ± 0.06, 3.04 ± 0.60, and 0.42 ± 0.10 μg/ml, respectively. The time to reach the maximum plasma concentration (Tmax was 0.79 ± 0.25, 0.42 ± 0.09, and 0.51 ± 0.13 h, respectively. The validated method was successfully applied to investigate the pharmacokinetics study of quercetin, luteolin, and apigenin in rat plasma after oral administration of M. chamomilla extract.

  9. Validation of a RP-HPLC-DAD Method for Chamomile (Matricaria recutita Preparations and Assessment of the Marker, Apigenin-7-glucoside, Safety and Anti-Inflammatory Effect

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    Felipe Galeti Miguel

    2015-01-01

    Full Text Available Chamomile is a medicinal plant, which presents several biological effects, especially the anti-inflammatory effect. One of the compounds related to this effect is apigenin, a flavonoid that is mostly found in its glycosylated form, apigenin-7-glucoside (APG, in natural sources. However, the affectivity and safety of this glycoside have not been well explored for topical application. In this context, the aim of this work was to develop and validate a reversed-phase high-performance liquid chromatography (RP-HPLC-DAD method to quantify APG in chamomile preparations. Additionally, the safety and the anti-inflammatory potential of this flavonoid were verified. The RP-HPLC-DAD method was developed and validated with linearity at 24.0–36.0 μg/mL range (r=0.9994. Intra- and interday precision (RSD were 0.27–2.66% and accuracy was 98.27–101.21%. The validated method was applied in the analysis of chamomile flower heads, glycolic extract, and Kamillen cream, supporting the method application in the quality control of chamomile preparations. Furthermore, the APG safety was assessed by MTT cytotoxicity assay and mutagenic protocols and the anti-inflammatory activity was confirmed by a diminished TNF-α production showed by mice macrophages treated with APG following LPS treatment.

  10. Validation of a RP-HPLC-DAD Method for Chamomile (Matricaria recutita) Preparations and Assessment of the Marker, Apigenin-7-glucoside, Safety and Anti-Inflammatory Effect

    Science.gov (United States)

    Miguel, Felipe Galeti; Spinola, Nathália Favaretto; Ribeiro, Diego Luis; Barcelos, Gustavo Rafael Mazzaron; Antunes, Lusânia Maria Greggi; Hori, Juliana Issa; Marquele-Oliveira, Franciane; Rocha, Bruno Alves; Berretta, Andresa Aparecida

    2015-01-01

    Chamomile is a medicinal plant, which presents several biological effects, especially the anti-inflammatory effect. One of the compounds related to this effect is apigenin, a flavonoid that is mostly found in its glycosylated form, apigenin-7-glucoside (APG), in natural sources. However, the affectivity and safety of this glycoside have not been well explored for topical application. In this context, the aim of this work was to develop and validate a reversed-phase high-performance liquid chromatography (RP-HPLC-DAD) method to quantify APG in chamomile preparations. Additionally, the safety and the anti-inflammatory potential of this flavonoid were verified. The RP-HPLC-DAD method was developed and validated with linearity at 24.0–36.0 μg/mL range (r = 0.9994). Intra- and interday precision (RSD) were 0.27–2.66% and accuracy was 98.27–101.21%. The validated method was applied in the analysis of chamomile flower heads, glycolic extract, and Kamillen cream, supporting the method application in the quality control of chamomile preparations. Furthermore, the APG safety was assessed by MTT cytotoxicity assay and mutagenic protocols and the anti-inflammatory activity was confirmed by a diminished TNF-α production showed by mice macrophages treated with APG following LPS treatment. PMID:26421053

  11. Inhibition of chrysin on xanthine oxidase activity and its inhibition mechanism.

    Science.gov (United States)

    Lin, Suyun; Zhang, Guowen; Liao, Yijing; Pan, Junhui

    2015-11-01

    Chrysin, a bioactive flavonoid, was investigated for its potential to inhibit the activity of xanthine oxidase (XO), a key enzyme catalyzing xanthine to uric acid and finally causing gout. The kinetic analysis showed that chrysin possessed a strong inhibition on XO ability in a reversible competitive manner with IC50 value of (1.26±0.04)×10(-6)molL(-1). The results of fluorescence titrations indicated that chrysin bound to XO with high affinity, and the interaction was predominately driven by hydrogen bonds and van der Waals forces. Analysis of circular dichroism demonstrated that chrysin induced the conformational change of XO with increases in α-helix and β-sheet and reductions in β-turn and random coil structures. Molecular simulation revealed that chrysin interacted with the amino acid residues Leu648, Phe649, Glu802, Leu873, Ser876, Glu879, Arg880, Phe1009, Thr1010, Val1011 and Phe1013 located within the active cavity of XO. The mechanism of chrysin on XO activity may be the insertion of chrysin into the active site occupying the catalytic center of XO to avoid the entrance of xanthine and causing conformational changes in XO. Furthermore, the interaction assays indicated that chrysin and its structural analog apigenin exhibited an additive effect on inhibition of XO. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Berry and Citrus Phenolic Compounds Inhibit Dipeptidyl Peptidase IV: Implications in Diabetes Management

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    Junfeng Fan

    2013-01-01

    Full Text Available Beneficial health effects of fruits and vegetables in the diet have been attributed to their high flavonoid content. Dipeptidyl peptidase IV (DPP-IV is a serine aminopeptidase that is a novel target for type 2 diabetes therapy due to its incretin hormone regulatory effects. In this study, well-characterized anthocyanins (ANC isolated from berry wine blends and twenty-seven other phenolic compounds commonly present in citrus, berry, grape, and soybean, were individually investigated for their inhibitory effects on DPP-IV by using a luminescence assay and computational modeling. ANC from blueberry-blackberry wine blends strongly inhibited DPP-IV activity (IC50, 0.07 ± 0.02 to >300 μM. Of the twenty-seven phenolics tested, the most potent DPP-IV inhibitors were resveratrol (IC50, 0.6 ± 0.4 nM, luteolin (0.12 ± 0.01 μM, apigenin (0.14 ± 0.02 μM, and flavone (0.17 ± 0.01 μM, with IC50 values lower than diprotin A (4.21 ± 2.01 μM, a reference standard inhibitory compound. Analyses of computational modeling showed that resveratrol and flavone were competitive inhibitors which could dock directly into all three active sites of DPP-IV, while luteolin and apigenin docked in a noncompetitive manner. Hydrogen bonding was the main binding mode of all tested phenolic compounds with DPP-IV. These results indicate that flavonoids, particularly luteolin, apigenin, and flavone, and the stilbenoid resveratrol can act as naturally occurring DPP-IV inhibitors.

  13. Absorption Properties of Luteolin and Apigenin in Genkwa Flos Using In Situ Single-Pass Intestinal Perfusion System in the Rat.

    Science.gov (United States)

    He, Xin; Song, Zi-Jing; Jiang, Cui-Ping; Zhang, Chun-Feng

    2017-01-01

    The flower bud of Daphne genkwa (Genkwa Flos) is a commonly used herbal medicine in Asian countries. Luteolin and apigenin are two recognized active flavonoids in Genkwa Flos. The aim of this study was to investigate the intestinal absorption mechanisms of Genkwa Flos flavonoids using in situ single-pass intestinal perfusion rat model. Using HPLC, we determined its major effective flavonoids luteolin, apigenin, as well as, hydroxygenkwanin and genkwanin in biological samples. The intestinal absorption mechanisms of the total flavonoids in Genkwa Flos (TFG) were investigated using in situ single-pass intestinal perfusion rat model. Comparing the TFG absorption rate in different intestinal segments, data showed that the small intestine absorption was significantly higher than that of the colon ([Formula: see text]). Compared with duodenum and ileum, the jejunum was the best small intestinal site for TFG absorption. The high TFG concentration (61.48[Formula: see text][Formula: see text]g/ml) yielded the highest permeability ([Formula: see text]). Subsequently, three membrane protein inhibitors (verapamil, pantoprazole and probenecid) were used to explore the TFG absorption pathways. Data showed probenecid, a multidrug resistance protein (or MRP) inhibitor, effectively enhanced the TFG absorption ([Formula: see text]). Furthermore, by comparing commonly used natural absorption enhancers on TFG, it was observed that camphor was the most effective. In Situ single-pass intestinal perfusion experiment shows that TFG absorption is much higher in the small intestine than in the colon, and the TFG is absorbed mainly via an active transport pathway with MRP-mediated efflux mechanism. Camphor obviously enhanced the TFG absorption, and this could be an effective TFG formulation preparation method to increase clinical effectiveness after Genkwa Flos administration. Our study elucidated the TFG absorption mechanisms, and provided new information for its formulation preparation.

  14. Development and validation of an HPTLC method for apigenin 7-O-glucoside in chamomile flowers and its application for fingerprint discrimination of chamomile-like materials.

    Science.gov (United States)

    Guzelmeric, Etil; Vovk, Irena; Yesilada, Erdem

    2015-03-25

    Brewed tea of chamomile flowers (Matricaria recutita L.) (Asteraceae) has been extensively consumed for centuries due to either its pleasant taste or medicinal purposes. On the other hand, the major problem is difficulty in distinguishing the genuine specimen when supplying chamomile through nature-picking. Consequently flowers of other Asteraceae members resembling to chamomile in appearance may frequently be practiced by lay people or marketed in spice shops or bazaars. Evidently detection of such adulterations plays a vital role in terms of public health to avoid risk of toxicity (i.e. pyrazolidin alkaloids) and ineffective treatments (lack or insufficient concentration of the active constituents). This work presents either development and validation of a high performance thin-layer chromatographic (HPTLC) method for apigenin 7-O-glucoside which is one of the active markers in chamomile flowers or its application for the fingerprint discrimination of chamomile-like materials i.e. Anthemis spp., Bellis spp., Chrysanthemum sp. and Tanacetum sp. gathered by local people assuming as chamomile. Separation was performed on the silica gel 60 NH2 F254s HPTLC plates using the developing solvent system of ethyl acetate-formic acid-acetic acid-water (30:1.5:1.5:3, v/v/v/v). The proposed HPTLC method may also be a leading guide for the quality assessment of chamomile tea products on the market. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Catalase inhibition an anti cancer property of flavonoids: A kinetic and structural evaluation.

    Science.gov (United States)

    Majumder, Debashis; Das, Asmita; Saha, Chabita

    2017-11-01

    Flavonoids are dietary polyphenols that present abundantly in fruits and vegetables. Flavonoids have inhibitory effects on enzymes and catalase is one among them. Catalase is a common enzyme ubiquitously found in all living organisms exposed to oxygen. It catalyzes the decomposition of hydrogen peroxide to water and oxygen (2H 2 O 2 →2H 2 O+O 2 ) . Inhibition of pure and cellular catalase from K562 cells by flavonoids was similar and exhibited the following efficacy; Myrecetin>Quercetin>Kaempferol and Quercetin>Luteolin>Apigenin demonstrating structure activity relationship. Circular Dichroism (CD) spectra have shown distinct loss in α-helical structure of the catalase on interaction with the flavonoids. All flavonoids inhibited the catalase activity by uncompetitive mechanism. The K m and V max values of pure catalase were observed to be 294mM -1 and 0.222mM -1 s -1 respectively and on inhibition with myrecetin the values decreased to a minimum of 23mM -1 and 0.014mM -1 s -1 respectively. Inhibition of catalase will directly results in increased production of Reactive Oxygen Species (ROS) and pro-oxidant property of flavonoids. This inhibition was reversed in presence of Cu 2+ ions because of the chelating affect of flavonoids. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Hydrophobic Interactions Are a Key to MDM2 Inhibition by Polyphenols as Revealed by Molecular Dynamics Simulations and MM/PBSA Free Energy Calculations.

    Directory of Open Access Journals (Sweden)

    Sharad Verma

    Full Text Available p53, a tumor suppressor protein, has been proven to regulate the cell cycle, apoptosis, and DNA repair to prevent malignant transformation. MDM2 regulates activity of p53 and inhibits its binding to DNA. In the present study, we elucidated the MDM2 inhibition potential of polyphenols (Apigenin, Fisetin, Galangin and Luteolin by MD simulation and MM/PBSA free energy calculations. All polyphenols bind to hydrophobic groove of MDM2 and the binding was found to be stable throughout MD simulation. Luteolin showed the highest negative binding free energy value of -173.80 kJ/mol followed by Fisetin with value of -172.25 kJ/mol. It was found by free energy calculations, that hydrophobic interactions (vdW energy have major contribution in binding free energy.

  17. Inhibition of dental plaque formation by toothpaste containing propolis

    Directory of Open Access Journals (Sweden)

    Nurin Aisyiyah Listyasari

    2012-12-01

    Full Text Available Background: Plaque is the main cause of caries and periodontal disease. Caries and periodontal disease can be prevented by inhibiting dental plaque formation. To inhibit the formation of plaque, teeth must be brushed with toothpaste. According to previous studies, propolis contains apigenin and tt-farnesol classified as flavonoid that can inhibit the formation of dental plaque by inhibiting glucosyltransferase enzym and membrane integrity of Streptococcus mutans. Purpose: The aim of this study was to determine the effect of toothpaste containing propolis on the formation of dental plaque. Methods: Post test with only control group design was used. The subjects of this study were 30 boarding school students of Hidayatullah, Yayasan Al-Burhan, Gedawang, Semarang, divided into two groups, randomized control group and treatment group. Control group was not treated with toothpaste contanining propolis. Meanwhile, treatment group was treated with toothpaste containing propolis. Plaque then was measured by using plaque index of Sillness and Loe method after using toothpaste containing propolis for four hours. Afterwards, the data was analyzed by a computer program, Mann-Whitney test, with its significance p < 0.05. Results: The result of Mann-Whitney test showed a significant difference, 0.002 (p < 0.05, between the control group and the treatment group. The median of the control group was about 3.41, while that of the treatment group was about 0.58. Conclusion: The use of toothpaste contaning propolis can prevent dental plaque formation.Latar belakang: Plak merupakan penyebab utama terjadinya karies dan penyakit periodontal. Karies dan penyakit periodontal dapat dicegah dengan menghambat pembentukan plak gigi. Untuk mencegah terbentuknya plak, gigi harus digosok menggunakan pasta gigi. Penelitian terdahulu menyebutkan bahwa propolis mengandung flavonoid apigenin dan tt-farnesol yang mampu menghambat aktivitas enzim glukosiltransferase dan menghambat

  18. In vitro effects of myricetin, morin, apigenin, (+)-taxifolin, (+)-catechin, (−)-epicatechin, naringenin and naringin on cytochrome b5 reduction by purified NADH-cytochrome b5 reductase

    International Nuclear Information System (INIS)

    Çelik, Haydar; Koşar, Müberra; Arinç, Emel

    2013-01-01

    Highlights: • We assessed inhibitory effects of 8 dietary flavonoids on cytochrome b5 reduction by purified NADH-cytochrome b5 reductase. • The flavonol myricetin was the most potent in inhibiting cytochrome b5 reduction with an IC 50 value of 0.35 μM. • We investigated kinetics of myricetin-induced inhibition in detail. • We explored the structure–inhibitory activity relationship of compounds. • Modulation of cytochrome b5 reduction indicates a potential for myricetin to lead to some food–drug/xenobiotic interactions. - Abstract: The microsomal NADH-dependent electron transport system consisting of cytochrome b5 reductase and cytochrome b5 participates in a number of physiologically important processes including lipid metabolism as well as is involved in the metabolism of various drug and xenobiotics. In the present study, we assessed the inhibitory effects of eight dietary flavonoids representing five distinct chemical classes on cytochrome b5 reduction by purified cytochrome b5 reductase. From the flavonoids tested, myricetin was the most potent in inhibiting cytochrome b5 reduction with an IC 50 value of 0.35 μM. Myricetin inhibited b5 reductase noncompetitively with a K i of 0.21 μM with respect to cofactor NADH, and exhibited a non-linear relationship indicating non-Michaelis–Menten kinetic binding with respect to cytochrome b5. In contrast to the potent inhibitory activity of myricetin, (+)-taxifolin was found to be a weak inhibitor (IC 50 = 9.8 μM). The remaining flavonoids were inactive within the concentration range tested (1–50 μM). Analysis of structure–activity data suggested that simultaneous presence of three OH groups in ring B is a primary structural determinant for a potent enzyme inhibition. Our results suggest that inhibition of the activity of this system by myricetin or myricetin containing diets may influence the metabolism of therapeutic drugs as well as detoxification of xenobiotics

  19. INHIBITION IN SPEAKING PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Isna Humaera

    2015-09-01

    Full Text Available The most common problem encountered by the learner in the language acquisition process is learner inhibition. Inhibition refers to a temperamental tendency to display wariness, fearfulness, or restrain in response to unfamiliar people, objects, and situations. There are some factors that cause inhibition, such as lack of motivation, shyness, self-confidence, self-esteem, and language ego. There are also levels of inhibition, it refers to kinds of inhibition and caused of inhibition itself. Teacher can support their students to reduce their inhibition effect by many ways, one of them by creating good classroom management including establishing good rapport between teacher and learners.

  20. Tyrosinase inhibition and antioxidant properties of Asphodelus microcarpus extracts.

    Science.gov (United States)

    Di Petrillo, Amalia; González-Paramás, Ana Maria; Era, Benedetta; Medda, Rosaria; Pintus, Francesca; Santos-Buelga, Celestino; Fais, Antonella

    2016-11-09

    Asphodelus microcarpus belongs to the family Liliaceae that include several medicinal plants. In the traditional medicine plants of the genus Asphodelus are used to treat skin disorders such as ectodermal parasites, psoriasis, microbial infection and for lightening freckles. In order to find novel skin depigmenting agents, the present work was carry out to evaluate antioxidant activity and tyrosinase inhibitory potential of leaves, flowers and tubers extracts of A. microcarpus. The phytochemical composition of the active extract was also evaluated. Three different extracts (water, methanol and ethanol) from leaves, flowers and tubers of A. microcarpus were evaluated for their inhibitory effect on tyrosinase activity using L-3,4-dihydroxyphenylalanine (L-DOPA) as substrate. Inhibition of cellular tyrosinase activity and melanin production was also investigated in melanoma B16F10 cells. Antioxidant activity, total phenolic and flavonoids contents were determined using standard in vitro methods. HPLC-DAD-MS was used to identify phenolic profile of the active extract. The results showed that all extracts have a direct inhibitory anti-tyrosinase activity, with ethanolic extract from flowers (FEE) exhibiting the stronger effect. Kinetic analysis revealed that FEE acts as an uncompetitive inhibitor with a Ki value of 0.19 mg/mL. The same effect was observed in murine melanoma B16F10 cells. Cellular tyrosinase activity as well as melanin content were reduced in FEE-treated cells. The results were comparable to that of the standard tyrosinase inhibitor (kojic acid). Furthermore, the same extract showed the highest antioxidant activity and an elevated levels of total phenolics and flavonoid content. Eleven phenolic components were identified as chlorogenic acid, luteolin derivates, naringenin and apigenin. Our findings showed that FEE from A. microcarpus inhibits tyrosinase and exerted antimelanogenesis effect in B16F10 cells. This extract also showed the highest scavenging

  1. Correlation between the potency of flavonoids for cytochrome c reduction and inhibition of cardiolipin-induced peroxidase activity.

    Science.gov (United States)

    Lagoa, Ricardo; Samhan-Arias, Alejandro K; Gutierrez-Merino, Carlos

    2017-05-06

    There are large differences between flavonoids to protect against apoptosis, a process in which cytochrome c (Cyt c) plays a key role. In this work, we show that 7 of 13 flavonoids studied have a capacity to reduce Cyt c similar or higher than ascorbate, the flavonols quercetin, kaempferol and myricetin, flavanol epigallocatechin-gallate, anthocyanidins cyanidin and malvidin, and the flavone luteolin. In contrast, the kaempferol 3(O)- and 3,4'(O)-methylated forms, the flavanone naringenin, and also apigenin and chrysin, had a negligible reducing capacity. Equilibrium dialysis and quenching of 1,6-diphenyl-1,3,5-hexatriene fluorescence experiments showed that flavonoids did not interfere with Cyt c binding to cardiolipin (CL)/phosphatidylcholine (PC) vesicles. However, the CL-induced loss of Cyt c Soret band intensity was largely attenuated by flavonoids, pointing out a stabilizing action against Cyt c unfolding in the complex. Moreover, flavonoids that behave as Cyt c reductants also inhibited the pro-apoptotic CL-induced peroxidase activity of Cyt c, indicating that modulation of Cyt c signaling are probable mechanisms behind the protective biological activities of flavonoids. © 2016 BioFactors, 43(3):451-468, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

  2. TV Inhibiting Creative Ideas

    Science.gov (United States)

    Intellect, 1977

    1977-01-01

    Television may be inhibiting our ability to create new ideas, according to Eric Somers, assistant professor of journalism at Drake University. Discusses television's role as facilitator of information and how it should improve to increase organization and the creative process. (Editor/RK)

  3. Enzyme inhibition by iminosugars

    DEFF Research Database (Denmark)

    López, Óscar; Qing, Feng-Ling; Pedersen, Christian Marcus

    2013-01-01

    Imino- and azasugar glycosidase inhibitors display pH dependant inhibition reflecting that both the inhibitor and the enzyme active site have groups that change protonation state with pH. With the enzyme having two acidic groups and the inhibitor one basic group, enzyme-inhibitor complexes...

  4. Inhibiting the inevitable

    DEFF Research Database (Denmark)

    Shashoua, Yvonne

    2006-01-01

    conservation is to ‘buy time’ for the object. Inhibitive conservation of plastics involves the removal or reduction of factors causing or accelerating degradation including light, oxygen, acids, relative humidity and acidic breakdown products. Specific approaches to conservation have been developed......Once plastics objects are registered in museum collections, the institution becomes responsible for their long term preservation, until the end of their useful lifetime. Plastics appear to deteriorate faster than other materials in museum collections and have a useful lifetime between 5 and 25...... years. Preventive or inhibitive conservation involves controlling the environments in which objects are placed during storage and display, with the aim of slowing the major deterioration reactions. Once in progress, degradation of plastics cannot be stopped or reversed, so the aim of preventive...

  5. Plastics for corrosion inhibition

    CERN Document Server

    Goldade, Victor A; Makarevich, Anna V; Kestelman, Vladimir N

    2005-01-01

    The development of polymer composites containing inhibitors of metal corrosion is an important endeavour in modern materials science and technology. Corrosion inhibitors can be located in a polymer matrix in the solid, liquid or gaseous phase. This book details the thermodynamic principles for selecting these components, their compatibility and their effectiveness. The various mechanisms of metal protection – barrier, inhibiting and electromechanical – are considered, as are the conflicting requirements placed on the structure of the combined material. Two main classes of inhibited materials (structural and films/coatings) are described in detail. Examples are given of structural plastics used in friction units subjected to mechano-chemical wear and of polymer films/coatings for protecting metal objects against corrosion.

  6. Beneficial bacteria inhibit cachexia

    Science.gov (United States)

    Varian, Bernard J.; Goureshetti, Sravya; Poutahidis, Theofilos; Lakritz, Jessica R.; Levkovich, Tatiana; Kwok, Caitlin; Teliousis, Konstantinos; Ibrahim, Yassin M.; Mirabal, Sheyla; Erdman, Susan E.

    2016-01-01

    Muscle wasting, known as cachexia, is a debilitating condition associated with chronic inflammation such as during cancer. Beneficial microbes have been shown to optimize systemic inflammatory tone during good health; however, interactions between microbes and host immunity in the context of cachexia are incompletely understood. Here we use mouse models to test roles for bacteria in muscle wasting syndromes. We find that feeding of a human commensal microbe, Lactobacillus reuteri, to mice is sufficient to lower systemic indices of inflammation and inhibit cachexia. Further, the microbial muscle-building phenomenon extends to normal aging as wild type animals exhibited increased growth hormone levels and up-regulation of transcription factor Forkhead Box N1 [FoxN1] associated with thymus gland retention and longevity. Interestingly, mice with a defective FoxN1 gene (athymic nude) fail to inhibit sarcopenia after L. reuteri therapy, indicating a FoxN1-mediated mechanism. In conclusion, symbiotic bacteria may serve to stimulate FoxN1 and thymic functions that regulate inflammation, offering possible alternatives for cachexia prevention and novel insights into roles for microbiota in mammalian ontogeny and phylogeny. PMID:26933816

  7. [Penicillium-inhibiting yeasts].

    Science.gov (United States)

    Benítez Ahrendts, M R; Carrillo, L

    2004-01-01

    The objective of this work was to establish the in vitro and in vivo inhibition of post-harvest pathogenic moulds by yeasts in order to make a biocontrol product. Post-harvest pathogenic moulds Penicillium digitatum, P. italicum, P. ulaiense, Phyllosticta sp., Galactomyces geotrichum and yeasts belonging to genera Brettanomyces, Candida, Cryptococcus, Kloeckera, Pichia, Rhodotorula were isolated from citrus fruits. Some yeasts strains were also isolated from other sources. The yeasts were identified by their macro and micro-morphology and physiological tests. The in vitro and in vivo activities against P. digitatum or P. ulaiense were different. Candida cantarellii and one strain of Pichia subpelliculosa produced a significant reduction of the lesion area caused by the pathogenic moulds P. digitatum and P. ulaiense, and could be used in a biocontrol product formulation.

  8. Selective inhibition of distracting input.

    Science.gov (United States)

    Noonan, MaryAnn P; Crittenden, Ben M; Jensen, Ole; Stokes, Mark G

    2017-10-16

    We review a series of studies exploring distractor suppression. It is often assumed that preparatory distractor suppression is controlled via top-down mechanisms of attention akin to those that prepare brain areas for target enhancement. Here, we consider two alternative mechanisms: secondary inhibition and expectation suppression within a predictive coding framework. We draw on behavioural studies, evidence from neuroimaging and some animal studies. We conclude that there is very limited evidence for selective top-down control of preparatory inhibition. By contrast, we argue that distractor suppression often relies secondary inhibition of non-target items (relatively non-selective inhibition) and on statistical regularities of the environment, learned through direct experience. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  9. [Concepts of inhibition in psychiatry].

    Science.gov (United States)

    Auroux, Y; Bourrat, M M; Brun, J P

    1978-01-01

    Following a historical approach, the authors first describe the original development of the concept of inhibition in neurophysiology and then analyze the subsequent adaptations made in psychiatry around such concept including those of: -- Pavlov, Hull, Watson and the behaviorists, -- Freud and the Freudian School, -- clinicians and psychopharmacologists. The concept of inhibition has thus various meanings in psychiatry. Although some unity is achieved on the semiological level, this aspect cannot explain the extent of the process.

  10. Homo economicus belief inhibits trust.

    Directory of Open Access Journals (Sweden)

    Ziqiang Xin

    Full Text Available As a foundational concept in economics, the homo economicus assumption regards humans as rational and self-interested actors. In contrast, trust requires individuals to believe partners' benevolence and unselfishness. Thus, the homo economicus belief may inhibit trust. The present three experiments demonstrated that the direct exposure to homo economicus belief can weaken trust. And economic situations like profit calculation can also activate individuals' homo economicus belief and inhibit their trust. It seems that people's increasing homo economicus belief may serve as one cause of the worldwide decline of trust.

  11. Homo economicus belief inhibits trust.

    Science.gov (United States)

    Xin, Ziqiang; Liu, Guofang

    2013-01-01

    As a foundational concept in economics, the homo economicus assumption regards humans as rational and self-interested actors. In contrast, trust requires individuals to believe partners' benevolence and unselfishness. Thus, the homo economicus belief may inhibit trust. The present three experiments demonstrated that the direct exposure to homo economicus belief can weaken trust. And economic situations like profit calculation can also activate individuals' homo economicus belief and inhibit their trust. It seems that people's increasing homo economicus belief may serve as one cause of the worldwide decline of trust.

  12. Testing of Biologically Inhibiting Surface

    DEFF Research Database (Denmark)

    Bill Madsen, Thomas; Larsen, Erup

    2003-01-01

    The main purpose of this course is to examine a newly developed biologically inhibiting material with regards to galvanic corrosion and electrochemical properties. More in detail, the concern was how the material would react when exposed to cleaning agents, here under CIP cleaning (Cleaning...

  13. On inhibition of dental erosion.

    Science.gov (United States)

    Rölla, Gunnar; Jonski, Grazyna; Saxegaard, Erik

    2013-11-01

    To examine the erosion-inhibiting effect of different concentrations of hydrofluoric acid. Thirty-six human molars were individually treated with 10 ml of 0.1 M citric acid for 30 min (Etch 1), acid was collected and stored until analysis. The teeth were randomly divided into six groups and then individually treated with 10 ml of one of six dilutions (from 0.1-1%) of hydrofluoric acid. The teeth were then again treated with citric acid (Etch 2). The individual acid samples from Etch 1 and 2 were analyzed for calcium by flame atomic absorption spectroscopy and difference in calcium loss was calculated. The highest erosion inhibiting effect was obtained in groups with the highest concentrations of hydrofluoric acid, where the pH was lowest, below pKa of 3.17, thus the hydrofluoric acids being mainly in an undissociated state. Diluted hydrofluoric acid is present in aqueous solution of SnF2 and TiF4 (which are known to inhibit dental erosion): SnF2 + 3H2O = Sn(OH)2 + 2HF + H2O and TiF4 + 5H2O = Ti(OH)4 + 4HF + H2O. It is also known that pure, diluted hydrofluoric acid can inhibit dental erosion. Teeth treated with hydrofluoric acid are covered by a layer of CaF2-like mineral. This mineral is acid resistant at pH acid resistant mineral, initiated by tooth enamel treatment with hydrofluoric acid. Hydrofluoric acid is different in having fluoride as a conjugated base, which provides this acid with unique properties.

  14. Reciprocal inhibition in Parkinson's disease.

    Science.gov (United States)

    Tsai, C H; Chen, R S; Lu, C S

    1997-01-01

    We studied the inhibition of median H-reflex by conditioning stimuli on the radial nerve in 14 normal controls, 6 patients with unilateral and 1 patient with predominantly left-sided Parkinson's disease. In normal controls, the electrophysiological studies were performed on their right hands, yet both hands were examined in patient group. In the controls, we identified three inhibitory phases, with maximal inhibition at conditioning-test intervals of 0 ms (41.66 +/- 4.73%), 20 ms (45.19 +/- 4.33%), and 100 ms (44.55 +/- 6.84%), respectively. In the less- or a- symptomatic side of the patient group, the inhibitory patterns are similar to those of the controls. However, in the symptomatic arms, loss of inhibition, or even mild potentiation, was observed in the third inhibitory phase. When the symptomatic and asymptomatic sides of patients were compared, in contrast to the striking phenomenon found between symptomatic side and the controls, no difference was observed in the third phase. The current results imply that, although no obvious rigidity can be detected on the asymptomatic sides, subtle functional corruption may have occurred within the contralateral basal ganglia in patients with unilateral Parkinson's disease. The remarkable change of the third phase on the symptomatic sides of patients suggests the perturbation of the polysynaptic long latency reflex pathway may somehow play a role in the rigidity pathogenesis.

  15. Aβ association inhibition by transferrin.

    Science.gov (United States)

    Raditsis, Annie V; Milojevic, Julijana; Melacini, Giuseppe

    2013-07-16

    The iron-transport glycoprotein transferrin has recently been shown to serve as a potent inhibitor of Aβ self-association. Although this novel, to our knowledge, inhibitory function of transferrin is of potential therapeutic interest for the treatment of Alzheimer's disease, the underlying mechanism is still not fully understood. Although it has been shown that the Fe(III) sequestration by transferrin reduces oxidative damage and Aβ aggregation, it is not clear whether transferrin is also able to inhibit Aβ self-association through direct binding of Aβ. Here, using saturation transfer and off-resonance relaxation NMR spectroscopy, we show that transferrin inhibits Aβ aggregation also by preferentially binding Aβ oligomers and outcompeting Aβ monomers that would otherwise cause the growth of the Aβ oligomers into larger assemblies. This inhibitory mechanism is different from the iron-sequestration model, but it is qualitatively similar to a mechanism previously proposed for the inhibition of Aβ self-association by another plasma and cerebrospinal fluid protein, i.e., human serum albumin. These results suggest that Aβ monomer competition through direct Aβ oligomer binding might be a general strategy adopted by proteins in plasma and cerebrospinal fluid to prevent Aβ aggregation. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  16. Serotonin, inhibition, and negative mood.

    Directory of Open Access Journals (Sweden)

    Peter Dayan

    2008-02-01

    Full Text Available Pavlovian predictions of future aversive outcomes lead to behavioral inhibition, suppression, and withdrawal. There is considerable evidence for the involvement of serotonin in both the learning of these predictions and the inhibitory consequences that ensue, although less for a causal relationship between the two. In the context of a highly simplified model of chains of affectively charged thoughts, we interpret the combined effects of serotonin in terms of pruning a tree of possible decisions, (i.e., eliminating those choices that have low or negative expected outcomes. We show how a drop in behavioral inhibition, putatively resulting from an experimentally or psychiatrically influenced drop in serotonin, could result in unexpectedly large negative prediction errors and a significant aversive shift in reinforcement statistics. We suggest an interpretation of this finding that helps dissolve the apparent contradiction between the fact that inhibition of serotonin reuptake is the first-line treatment of depression, although serotonin itself is most strongly linked with aversive rather than appetitive outcomes and predictions.

  17. Self-regulation, ego depletion, and inhibition.

    Science.gov (United States)

    Baumeister, Roy F

    2014-12-01

    Inhibition is a major form of self-regulation. As such, it depends on self-awareness and comparing oneself to standards and is also susceptible to fluctuations in willpower resources. Ego depletion is the state of reduced willpower caused by prior exertion of self-control. Ego depletion undermines inhibition both because restraints are weaker and because urges are felt more intensely than usual. Conscious inhibition of desires is a pervasive feature of everyday life and may be a requirement of life in civilized, cultural society, and in that sense it goes to the evolved core of human nature. Intentional inhibition not only restrains antisocial impulses but can also facilitate optimal performance, such as during test taking. Self-regulation and ego depletion- may also affect less intentional forms of inhibition, even chronic tendencies to inhibit. Broadly stated, inhibition is necessary for human social life and nearly all societies encourage and enforce it. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. NSAIDs inhibit tumorigenesis, but how?

    Science.gov (United States)

    Gurpinar, Evrim; Grizzle, William E; Piazza, Gary A

    2014-03-01

    Numerous epidemiologic studies have reported that the long-term use of nonsteroidal anti-inflammatory drugs (NSAID) is associated with a significant decrease in cancer incidence and delayed progression of malignant disease. The use of NSAIDs has also been linked with reduced risk from cancer-related mortality and distant metastasis. Certain prescription-strength NSAIDs, such as sulindac, have been shown to cause regression of precancerous lesions. Unfortunately, the extended use of NSAIDs for chemoprevention results in potentially fatal side effects related to their COX-inhibitory activity and suppression of prostaglandin synthesis. Although the basis for the tumor growth-inhibitory activity of NSAIDs likely involves multiple effects on tumor cells and their microenvironment, numerous investigators have concluded that the underlying mechanism is not completely explained by COX inhibition. It may therefore be possible to develop safer and more efficacious drugs by targeting such COX-independent mechanisms. NSAID derivatives or metabolites that lack COX-inhibitory activity, but retain or have improved anticancer activity, support this possibility. Experimental studies suggest that apoptosis induction and suppression of β-catenin-dependent transcription are important aspects of their antineoplastic activity. Studies show that the latter involves phosphodiesterase inhibition and the elevation of intracellular cyclic GMP levels. Here, we review the evidence for COX-independent mechanisms and discuss progress toward identifying alternative targets and developing NSAID derivatives that lack COX-inhibitory activity but have improved antineoplastic properties. ©2013 AACR

  19. Pharmacological inhibition of poly(ADP-ribose) polymerase inhibits angiogenesis

    International Nuclear Information System (INIS)

    Rajesh, Mohanraj; Mukhopadhyay, Partha; Batkai, Sandor; Godlewski, Grzegorz; Hasko, Gyoergy; Liaudet, Lucas; Pacher, Pal

    2006-01-01

    Poly(ADP-ribose) polymerase (PARP) is a nuclear enzyme which plays an important role in regulating cell death and cellular responses to DNA repair. Pharmacological inhibitors of PARP are being considered as treatment for cancer both in monotherapy as well as in combination with chemotherapeutic agents and radiation, and were also reported to be protective against untoward effects exerted by certain anticancer drugs. Here we show that pharmacological inhibition of PARP with 3-aminobenzamide or PJ-34 dose-dependently reduces VEGF-induced proliferation, migration, and tube formation of human umbilical vein endothelial cells in vitro. These results suggest that treatment with PARP inhibitors may exert additional benefits in various cancers and retinopathies by decreasing angiogenesis

  20. Selective and nonselective inhibition of competitors in picture naming

    NARCIS (Netherlands)

    Shao, Z.; Meyer, A.S.; Roelofs, A.P.A.

    2013-01-01

    The present study examined the relation between nonselective inhibition and selective inhibition in picture naming performance. Nonselective inhibition refers to the ability to suppress any unwanted response, whereas selective inhibition refers to the ability to suppress specific competing

  1. Greener Approach towards Corrosion Inhibition

    Directory of Open Access Journals (Sweden)

    Neha Patni

    2013-01-01

    Full Text Available Corrosion control of metals is technically, economically, environmentally, and aesthetically important. The best option is to use inhibitors for protecting metals and alloys against corrosion. As organic corrosion inhibitors are toxic in nature, so green inhibitors which are biodegradable, without any heavy metals and other toxic compounds, are promoted. Also plant products are inexpensive, renewable, and readily available. Tannins, organic amino acids, alkaloids, and organic dyes of plant origin have good corrosion-inhibiting abilities. Plant extracts contain many organic compounds, having polar atoms such as O, P, S, and N. These are adsorbed on the metal surface by these polar atoms, and protective films are formed, and various adsorption isotherms are obeyed. Various types of green inhibitors and their effect on different metals are mentioned in the paper.

  2. Cellulase Inhibition by High Concentrations of Monosaccharides

    DEFF Research Database (Denmark)

    Hsieh, Chia-Wen; Cannella, David; Jørgensen, Henning

    2014-01-01

    Biological degradation of biomass on an industrial scale culminates in high concentrations of end products. It is known that the accumulation of glucose and cellobiose, end products of hydrolysis, inhibit cellulases and decrease glucose yields. Aside from these end products, however, other monosa...... glucose. Protein adsorption studies showed that this inhibition e ff ect was most likely due to catalytic, and not binding, inhibition of the cellulases....

  3. Inhibition of Intrinsic Thrombin Generation

    Directory of Open Access Journals (Sweden)

    Thomas W. Stief MD

    2006-01-01

    Full Text Available Background The contact phase of coagulation is of physiologic/pathophysiologic importance, whenever unphysiologic polynegative substances such as cell fragments (microparticles get in contact with blood. There are several clinically used inhibitors of intrinsic thrombin generation. Here the inhibitory concentrations 50% (IC50 of these anticoagulants are measured by the highly specific thrombin generation assay INCA. Methods Unfrozen pooled normal citrated plasma in polystyrole tubes was supplemented at 23°C in duplicate with 0–2 IU/ml low molecular weight heparin (dalteparin, 0–2 IU/ml unfractionated heparin, 0–500 KIU/ml aprotinin, or 0–40 mM arginine. 50 μl plasma or 1 IU/ml thrombin standard were pipetted into a polystyrole microtiter plate with flat bottom. 5 μl SiO 2 /CaCl 2 - reagent (INCA activator were added and after 0–30 min incubation at 37°C 100 μl 2.5 M arginine, pH 8.6, were added; arginine inhibits hemostasis activation and depolymerizes generated fibrin within 20 min at 23°C. The in the physiologic 37°C incubation phase generated thrombin was then chromogenically detected. The intra-assay CV values were < 5%. Results and Discussion The approximate IC50 were 0.01 IU/ml dalteparin, 0.02 IU/ml heparin, 25 KIU/ml aprotinin, and 12 mM arginine. The efficiency of any anticoagulant on intrinsic thrombin generation should be measured for each individual patient. Abbreviations IIa, thrombin; δA, increase in absorbance; APTT, activated partial thromboplastin time; CRT, coagulation reaction time (at 37°C in water-bath; F-wells, polystyrole microtiter plates with flat bottom; IC50, inhibitory concentration 50%; INCA, intrinsic coagulation activity assay; IU, international units; KIU, kallikrein inhibiting unis; LMWH, low molecular weight heparin; mA, milli-absorbance units; PSL, pathromtin SL®; RT, room temperature (23°C; U-wells, polystyrole microtiter plates with round bottom.

  4. Allosteric Inhibition Through Core Disruption

    Energy Technology Data Exchange (ETDEWEB)

    Horn, James R.; Shoichet, Brian K. (NWU); (UCSF)

    2010-03-05

    Although inhibitors typically bind pre-formed sites on proteins, it is theoretically possible to inhibit by disrupting the folded structure of a protein or, in the limit, to bind preferentially to the unfolded state. Equilibria defining how such molecules act are well understood, but structural models for such binding are unknown. Two novel inhibitors of {beta}-lactamase were found to destabilize the enzyme at high temperatures, but at lower temperatures showed no preference for destabilized mutant enzymes versus stabilized mutants. X-ray crystal structures showed that both inhibitors bound to a cryptic site in {beta}-lactamase, which the inhibitors themselves created by forcing apart helixes 11 and 12. This opened up a portion of the hydrophobic core of the protein, into which these two inhibitors bind. Although this binding site is 16 {angstrom} from the center of the active site, the conformational changes were transmitted through a sequence of linked motions to a key catalytic residue, Arg244, which in the complex adopts conformations very different from those in catalytically competent enzyme conformations. These structures offer a detailed view of what has heretofore been a theoretical construct, and suggest the possibility for further design against this novel site.

  5. Reduced surround inhibition in musicians.

    Science.gov (United States)

    Shin, Hae-Won; Kang, Suk Y; Hallett, Mark; Sohn, Young H

    2012-06-01

    To investigate whether surround inhibition (SI) in the motor system is altered in professional musicians, we performed a transcranial magnetic stimulation (TMS) study in 10 professional musicians and 15 age-matched healthy non-musicians. TMS was set to be triggered by self-initiated flexion of the index finger at different intervals ranging from 3 to 1,000 ms. Average motor evoked potential (MEP) amplitudes obtained from self-triggered TMS were normalized to average MEPs of the control TMS at rest and expressed as a percentage. Normalized MEP amplitudes of the abductor digiti minimi (ADM) muscles were compared between the musicians and non-musicians with the primary analysis being the intervals between 3 and 80 ms (during the movement). A mixed-design ANOVA revealed a significant difference in normalized ADM MEPs during the index finger flexion between groups, with less SI in the musicians. This study demonstrated that the functional operation of SI is less strong in musicians than non-musicians, perhaps due to practice of movement synergies involving both muscles. Reduced SI, however, could lead susceptible musicians to be prone to develop task-specific dystonia.

  6. Quorum Sensing Inhibition, Relevance to Periodontics

    OpenAIRE

    Yada, Sudheer; Kamalesh, B; Sonwane, Siddharth; Guptha, Indra; Swetha, R K

    2015-01-01

    Quorum sensing helps bacteria to communicate with each other and in coordinating their behavior. Many diseases of human beings, plants, and animals are mediated by quorum sensing. Various approaches are being tried to inhibit this communication to control the diseases caused by bacteria. Periodontal pathogens also communicate through quorum sensing and new approaches to treat periodontal disease using quorum sensing inhibition need to explored.

  7. The pharmacology of visuospatial attention and inhibition

    NARCIS (Netherlands)

    Logemann, H.N.A.

    2013-01-01

    Attention and inhibition are of vital importance in everyday functioning. Problems of attention and inhibition are central to disorders such as Attention Deficit/Hyperactivity Disorder (ADHD). Both bias and disengagement key components of visuospatial attention. Bias refers to neuronal signals that

  8. Inhibition: Mental Control Process or Mental Resource?

    Science.gov (United States)

    Im-Bolter, Nancie; Johnson, Janice; Ling, Daphne; Pascual-Leone, Juan

    2015-01-01

    The current study tested 2 models of inhibition in 45 children with language impairment and 45 children with normally developing language; children were aged 7 to 12 years. Of interest was whether a model of inhibition as a mental-control process (i.e., executive function) or as a mental resource would more accurately reflect the relations among…

  9. Optimal Decision Making in Neural Inhibition Models

    Science.gov (United States)

    van Ravenzwaaij, Don; van der Maas, Han L. J.; Wagenmakers, Eric-Jan

    2012-01-01

    In their influential "Psychological Review" article, Bogacz, Brown, Moehlis, Holmes, and Cohen (2006) discussed optimal decision making as accomplished by the drift diffusion model (DDM). The authors showed that neural inhibition models, such as the leaky competing accumulator model (LCA) and the feedforward inhibition model (FFI), can mimic the…

  10. A Qualitative Approach to Enzyme Inhibition

    Science.gov (United States)

    Waldrop, Grover L.

    2009-01-01

    Most general biochemistry textbooks present enzyme inhibition by showing how the basic Michaelis-Menten parameters K[subscript m] and V[subscript max] are affected mathematically by a particular type of inhibitor. This approach, while mathematically rigorous, does not lend itself to understanding how inhibition patterns are used to determine the…

  11. Contour Detection Operators Based on Surround Inhibition

    NARCIS (Netherlands)

    Grigorescu, Cosmin; Petkov, Nicolai; Westenberg, Michel A.

    2003-01-01

    We propose a biologically motivated computational step, called non-classical receptive field (non-CRF) inhibition, to improve contour detection in images of natural scenes. We augment a Gabor energy operator with non-CRF inhibition. The resulting contour operator responds strongly to isolated lines,

  12. Quorum sensing inhibition, relevance to periodontics.

    Science.gov (United States)

    Yada, Sudheer; Kamalesh, B; Sonwane, Siddharth; Guptha, Indra; Swetha, R K

    2015-01-01

    Quorum sensing helps bacteria to communicate with each other and in coordinating their behavior. Many diseases of human beings, plants, and animals are mediated by quorum sensing. Various approaches are being tried to inhibit this communication to control the diseases caused by bacteria. Periodontal pathogens also communicate through quorum sensing and new approaches to treat periodontal disease using quorum sensing inhibition need to explored.

  13. Adsorptive, Kinetic, Thermodynamic and Inhibitive Properties of ...

    African Journals Online (AJOL)

    The adsorption of Cissus populnea stem extract and its subsequent corrosion inhibition properties on aluminum in 0.5 M HCl solutions have been investigated using weight loss measurements. Inhibition efficiency of the plant extract increased with concentration but decreased with rise in temperature. The adsorption of the ...

  14. BST2/Tetherin Inhibition of Alphavirus Exit

    Directory of Open Access Journals (Sweden)

    Yaw Shin Ooi

    2015-04-01

    Full Text Available Alphaviruses such as chikungunya virus (CHIKV and Semliki Forest virus (SFV are small enveloped RNA viruses that bud from the plasma membrane. Tetherin/BST2 is an interferon-induced host membrane protein that inhibits the release of many enveloped viruses via direct tethering of budded particles to the cell surface. Alphaviruses have highly organized structures and exclude host membrane proteins from the site of budding, suggesting that their release might be insensitive to tetherin inhibition. Here, we demonstrated that exogenously-expressed tetherin efficiently inhibited the release of SFV and CHIKV particles from host cells without affecting virus entry and infection. Alphavirus release was also inhibited by the endogenous levels of tetherin in HeLa cells. While rubella virus (RuV and dengue virus (DENV have structural similarities to alphaviruses, tetherin inhibited the release of RuV but not DENV. We found that two recently identified tetherin isoforms differing in length at the N-terminus exhibited distinct capabilities in restricting alphavirus release. SFV exit was efficiently inhibited by the long isoform but not the short isoform of tetherin, while both isoforms inhibited vesicular stomatitis virus exit. Thus, in spite of the organized structure of the virus particle, tetherin specifically blocks alphavirus release and shows an interesting isoform requirement.

  15. Fear inhibition in high trait anxiety.

    Directory of Open Access Journals (Sweden)

    Merel Kindt

    Full Text Available Trait anxiety is recognized as an individual risk factor for the development of anxiety disorders but the neurobiological mechanisms remain unknown. Here we test whether trait anxiety is associated with impaired fear inhibition utilizing the AX+/BX- conditional discrimination procedure that allows for the independent evaluation of startle fear potentiation and inhibition of fear. Sixty undergraduate students participated in the study--High Trait Anxious: n = 28 and Low Trait Anxious: n = 32. We replicated earlier findings that a transfer of conditioned inhibition for startle responses requires contingency awareness. However, contrary to the fear inhibition hypothesis, our data suggest that high trait anxious individuals show a normal fear inhibition of conditioned startle responding. Only at the cognitive level the high trait anxious individuals showed evidence for impaired inhibitory learning of the threat cue. Together with other findings where impaired fear inhibition was only observed in those PTSD patients who were either high on hyperarousal symptoms or with current anxiety symptoms, we question whether impaired fear inhibition is a biomarker for the development of anxiety disorders.

  16. Angiotensin inhibition in heart failure

    Directory of Open Access Journals (Sweden)

    John JV Mcmurray

    2004-03-01

    Full Text Available Survival in patients with heart failure remains very poor, and is worse than that for most common cancers, including bowel cancer in men and breast cancer in women. The renin-angiotensin-aldosterone system (RAAS is not completely blocked by angiotensin-converting enzyme (ACE inhibition. Blockade of the RAAS at the AT1-receptor has the theoretical benefit of more effective blockade of the actions of angiotensin II. ACE inhibitors (ACE-Is prevent the breakdown of bradykinin: this has been blamed for some of the unwanted effects of ACE-Is although bradykinin may have advantageous effects in heart failure. Consequently, ACE-Is and ARBs might be complementary or even additive treatments; recent trials have tested these hypotheses. The Candesartan in Heart failure Assessment of Reduction in Mortality and morbidity (CHARM programme compared the angiotensin receptor blocker (ARB candesartan (target dose 32 mg once daily to placebo in three distinct but complementary populations of patients with symptomatic heart failure. These were: patients with reduced left ventricular ejection fraction (LVEF who were ACE-I-intolerant (CHARM-Alternative; patients with reduced LVEF who were being treated with ACE-Is (CHARM-Added; and patients with preserved left ventricular systolic function (CHARM-Preserved. There were substantial and statistically significant reductions in the primary composite end point (risk of cardiovascular death or hospital admission for heart failure in CHARM-Alternative. This was also the case in CHARM-Added, supporting and extending the findings of Val-HeFT. In CHARM-Preserved, the effect of candesartan on the primary end point did not reach conventional statistical significance though hospital admission for heart failure was reduced significantly with candesartan. In the CHARM-Overall programme there was a statistically borderline reduction in all-cause mortality with a clear reduction in cardiovascular mortality. All-cause mortality was

  17. Angiotensin inhibition in heart failure

    Directory of Open Access Journals (Sweden)

    John JV McMurray

    2004-03-01

    Full Text Available Survival in patients with heart failure remains very poor, and is worse than that for most common cancers, including bowel cancer in men and breast cancer in women. The renin-angiotensin-aldosterone system (RAAS is not completely blocked by angiotensin-converting enzyme (ACE inhibition. Blockade of the RAAS at the AT1-receptor has the theoretical benefit of more effective blockade of the actions of angiotensin II. ACE inhibitors (ACE-Is prevent the breakdown of bradykinin: this has been blamed for some of the unwanted effects of ACE-Is although bradykinin may have advantageous effects in heart failure. Consequently, ACE-Is and ARBs might be complementary or even additive treatments; recent trials have tested these hypotheses.The Candesartan in Heart failure Assessment of Reduction in Mortality and morbidity (CHARM programme compared the angiotensin receptor blocker (ARB candesartan (target dose 32 mg once daily to placebo in three distinct but complementary populations of patients with symptomatic heart failure. These were: patients with reduced left ventricular ejection fraction (LVEF who were ACE-I-intolerant (CHARM-Alternative; patients with reduced LVEF who were being treated with ACE-Is (CHARM-Added; and patients with preserved left ventricular systolic function (CHARM-Preserved.There were substantial and statistically significant reductions in the primary composite end point (risk of cardiovascular death or hospital admission for heart failure in CHARM-Alternative. This was also the case in CHARM-Added, supporting and extending the findings of Val-HeFT. In CHARM-Preserved, the effect of candesartan on the primary end point did not reach conventional statistical significance though hospital admission for heart failure was reduced significantly with candesartan. In the CHARM-Overall programme there was a statistically borderline reduction in all-cause mortality with a clear reduction in cardiovascular mortality. All-cause mortality was

  18. Product inhibition of five Hypocrea jecorina cellulases

    DEFF Research Database (Denmark)

    Murphy, Leigh; Westh, Peter; Bohlin, Christina

    2013-01-01

    Product inhibition of cellulolytic enzymes has been deemed a critical factor in the industrial saccharification of cellulosic biomass. Several investigations have addressed this problem using crude enzyme preparations or commercial (mixed) cellulase products, but quantitative information...

  19. Single-molecule theory of enzymatic inhibition.

    Science.gov (United States)

    Robin, Tal; Reuveni, Shlomi; Urbakh, Michael

    2018-02-22

    The classical theory of enzymatic inhibition takes a deterministic, bulk based approach to quantitatively describe how inhibitors affect the progression of enzymatic reactions. Catalysis at the single-enzyme level is, however, inherently stochastic which could lead to strong deviations from classical predictions. To explore this, we take the single-enzyme perspective and rebuild the theory of enzymatic inhibition from the bottom up. We find that accounting for multi-conformational enzyme structure and intrinsic randomness should strongly change our view on the uncompetitive and mixed modes of inhibition. There, stochastic fluctuations at the single-enzyme level could make inhibitors act as activators; and we state-in terms of experimentally measurable quantities-a mathematical condition for the emergence of this surprising phenomenon. Our findings could explain why certain molecules that inhibit enzymatic activity when substrate concentrations are high, elicit a non-monotonic dose response when substrate concentrations are low.

  20. Inhibition of urinary calculi -- a spectroscopic study

    Science.gov (United States)

    Manciu, Felicia; Govani, Jayesh; Durrer, William; Reza, Layra; Pinales, Luis

    2008-10-01

    Although a considerable number of investigations have already been undertaken and many causes such as life habits, metabolic disorders, and genetic factors have been noted as sources that accelerate calculi depositions and aggregations, there are still plenty of unanswered questions regarding efficient inhibition and treatment mechanisms. Thus, in an attempt to acquire more insights, we propose here a detailed scientific study of kidney stone formation and growth inhibition based on a traditional medicine approach with Rotula Aquatica Lour (RAL) herbal extracts. A simplified single diffusion gel growth technique was used for synthesizing the samples for the present study. The unexpected Zn presence in the sample with RAL inhibitor, as revealed by XPS measurements, explains the inhibition process and the dramatic reflectance of the incident light observed in the infrared transmission studies. Raman data demonstrate potential binding of the inhibitor with the oxygen of the kidney stone. Photoluminescence results corroborate to provide additional evidence of Zn-related inhibition.

  1. Inhibition of 2-methoxyestradiol glucuronidation by probenecid.

    Science.gov (United States)

    Qian, Yuli; Sherbini, Ahmad; Matin, Bahar; Zhao, Yanli; Castellot, John; Greenblatt, David J

    2015-11-01

    2-Methoxyestradiol (2ME2), a metabolite of estradiol, has antitumour activity in vitro. However, potential clinical applicability has been limited by low oral bioavailability. Probenecid was evaluated in vitro as an inhibitor of 2ME2 glucuronidation for purposes of enhancing 2ME2 oral bioavailability. Human liver microsomes were used to determine kinetic parameters for transformation of 2ME2 to its glucuronide metabolites (M1, M2) and inhibition of the reactions by probenecid. M1 and M2 formation from 2ME2 proceeded with features of substrate inhibition. Probenecid inhibited metabolite formation, with mean inhibition constant (Ki ) values of 0.9 and 2.6 mM, respectively. Inhibition was reversible, with mixed competitive-non-competitive characteristics. The Ki values for probenecid inhibition of 2ME2 glucuronide formation, when compared to maximum probenecid plasma concentrations anticipated clinically, indicate that probenecid co-administration has the potential to augment systemic plasma levels of 2ME2 after oral dosage in humans. © 2015 Royal Pharmaceutical Society.

  2. Effects of Inhibition Conditions on Anammox process

    Science.gov (United States)

    Xie, Haitao; Ji, Dandan; Zang, Lihua

    2017-12-01

    Anaerobic ammonium oxidation (Anammox) is a very suitable process for the treatment of nitrogen-rich wastewater, which is a promising new biological nitrogen removal process, and has a good application prospects. However, the Anammox process is inhibited by many factors, which hinders the process improvement and the application of the Anammox process. Such as organic,temperature,salts,heavy metals, phosphates, sulfides, pH and other inhibitors are usually present in practical applications. We have reviewed the previous researches on the inhibition of Anammox processes. The effect of the substrate on the anaerobic oxide is mainly caused by free ammonia or nitrite nitrogen. Most heavy metals inhibit Anammox growth and activity. The inhibition of organic matter depends on the content of organic matter and species. High salinity inhibits Anammox activity. Dissolved oxygen allows the flora to be in a balanced state. The optimum pH and temperature, as well as other factors, can provide a good growth environment for Anammox. The knowledge of inhibition on Anammox will help prevent the application and improvement of the Anammox process.

  3. Inhibition of Heme Peroxidases by Melamine

    Directory of Open Access Journals (Sweden)

    Pattaraporn Vanachayangkul

    2012-01-01

    Full Text Available In 2008 melamine-contaminated infant formula and dairy products in China led to over 50,000 hospitalizations of children due to renal injuries. In North America during 2007 and in Asia during 2004, melamine-contaminated pet food products resulted in numerous pet deaths due to renal failure. Animal studies have confirmed the potent renal toxicity of melamine combined with cyanuric acid. We showed previously that the solubility of melamine cyanurate is low at physiologic pH and ionic strength, provoking us to speculate how toxic levels of these compounds could be transported through the circulation without crystallizing until passing into the renal filtrate. We hypothesized that melamine might be sequestered by heme proteins, which could interfere with heme enzyme activity. Four heme peroxidase enzymes were selected for study: horseradish peroxidase (HRP, lactoperoxidase (LPO, and cyclooxygenase-1 and -2 (COX-1 and -2. Melamine exhibited noncompetitive inhibition of HRP (9.5±0.7mM, and LPO showed a mixed model of inhibition (14.5±4.7mM. The inhibition of HRP and LPO was confirmed using a chemiluminescent peroxidase assay. Melamine also exhibited COX-1 inhibition, but inhibition of COX-2 was not detected. Thus, our results demonstrate that melamine inhibits the activity of three heme peroxidases.

  4. Inhibition in the Human Auditory Cortex.

    Directory of Open Access Journals (Sweden)

    Koji Inui

    Full Text Available Despite their indispensable roles in sensory processing, little is known about inhibitory interneurons in humans. Inhibitory postsynaptic potentials cannot be recorded non-invasively, at least in a pure form, in humans. We herein sought to clarify whether prepulse inhibition (PPI in the auditory cortex reflected inhibition via interneurons using magnetoencephalography. An abrupt increase in sound pressure by 10 dB in a continuous sound was used to evoke the test response, and PPI was observed by inserting a weak (5 dB increase for 1 ms prepulse. The time course of the inhibition evaluated by prepulses presented at 10-800 ms before the test stimulus showed at least two temporally distinct inhibitions peaking at approximately 20-60 and 600 ms that presumably reflected IPSPs by fast spiking, parvalbumin-positive cells and somatostatin-positive, Martinotti cells, respectively. In another experiment, we confirmed that the degree of the inhibition depended on the strength of the prepulse, but not on the amplitude of the prepulse-evoked cortical response, indicating that the prepulse-evoked excitatory response and prepulse-evoked inhibition reflected activation in two different pathways. Although many diseases such as schizophrenia may involve deficits in the inhibitory system, we do not have appropriate methods to evaluate them; therefore, the easy and non-invasive method described herein may be clinically useful.

  5. Inhibition of ethylene production by putrescine alleviates aluminium-induced root inhibition in wheat plants

    OpenAIRE

    Yu, Yan; Jin, Chongwei; Sun, Chengliang; Wang, Jinghong; Ye, Yiquan; Zhou, Weiwei; Lu, Lingli; Lin, Xianyong

    2016-01-01

    Inhibition of root elongation is one of the most distinct symptoms of aluminium (Al) toxicity. Although putrescine (Put) has been identified as an important signaling molecule involved in Al tolerance, it is yet unknown how Put mitigates Al-induced root inhibition. Here, the possible mechanism was investigated by using two wheat genotypes differing in Al resistance: Al-tolerant Xi Aimai-1 and Al-sensitive Yangmai-5. Aluminium caused more root inhibition in Yangmai-5 and increased ethylene pro...

  6. Simvastatin inhibits Candida albicans biofilm in vitro.

    Science.gov (United States)

    Liu, Geoffrey; Vellucci, Vincent F; Kyc, Stephanie; Hostetter, Margaret K

    2009-12-01

    By inhibiting the conversion of 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) to mevalonate, statins impair cholesterol metabolism in humans. We reasoned that statins might similarly interfere with the biosynthesis of ergosterol, the major sterol of the yeast cell membrane. As assessed by spectrophotometric and microscopic analysis, significant inhibition of biofilm production was noted after 16-h incubation with 1, 2.5, and 5 muM simvastatin, concentrations that did not affect growth, adhesion, or hyphal formation by C. albicans in vitro. Higher concentrations (10, 20, and 25 muM simvastatin) inhibited biofilm by >90% but also impaired growth. Addition of exogenous ergosterol (90 muM) overcame the effects of 1 and 2.5 muM simvastatin, suggesting that at least one mechanism of inhibition is interference with ergosterol biosynthesis. Clinical isolates from blood, skin, and mucosal surfaces produced biofilms; biofilms from bloodstream isolates were similarly inhibited by simvastatin. In the absence of fungicidal activity, simvastatin's interruption of a critical step in an essential metabolic pathway, highly conserved from yeast to man, has unexpected effects on biofilm production by a eukaryotic pathogen.

  7. Aspartate inhibits Staphylococcus aureus biofilm formation.

    Science.gov (United States)

    Yang, Hang; Wang, Mengyue; Yu, Junping; Wei, Hongping

    2015-04-01

    Biofilm formation renders Staphylococcus aureus highly resistant to conventional antibiotics and host defenses. Four D-amino acids (D-Leu, D-Met, D-Trp and D-Tyr) have been reported to be able to inhibit biofilm formation and disassemble established S. aureus biofilms. We report here for the first time that both D- and L-isoforms of aspartate (Asp) inhibited S. aureus biofilm formation on tissue culture plates. Similar biofilm inhibition effects were also observed against other staphylococcal strains, including S. saprophyticus, S. equorum, S. chromogenes and S. haemolyticus. It was found that Asp at high concentrations (>10 mM) inhibited the growth of planktonic N315 cells, but at subinhibitory concentrations decreased the cellular metabolic activity without influencing cell growth. The decreased cellular metabolic activity might be the reason for the production of less protein and DNA in the matrix of the biofilms formed in the presence of Asp. However, varied inhibition efficacies of Asp were observed for biofilms formed by clinical staphylococcal isolates. There might be mechanisms other than decreasing the metabolic activity, e.g. the biofilm phenotypes, affecting biofilm formation in the presence of Asp. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Levetiracetam inhibits neurotransmitter release associated with CICR.

    Science.gov (United States)

    Fukuyama, Kouji; Tanahashi, Shunsuke; Nakagawa, Masanori; Yamamura, Satoshi; Motomura, Eishi; Shiroyama, Takashi; Tanii, Hisashi; Okada, Motohiro

    2012-06-19

    To define the antiepileptic mechanisms of levetiracetam (LEV), the present study determined the concentration-dependent effects of locally perfused LEV on the releases of norepinephrine, dopamine, serotonin, l-glutamate and GABA induced by 50 mMK(+)-evoked stimulation and agonists of ryanodine receptor (RyR) and inositol-triphosphate receptor (IP3R) in the median prefrontal cortex (mPFC) using in vivo microdialysis. Local perfusion with LEV (10, 30 and 100 μM) alone did not affect the extracellular levels of all neurotransmitters in the mPFC. The release of neurotransmitters induced by K(+)-evoked stimulation was inhibited by perfusion with LEV in a concentration-dependent manner, and those induced by agonists of RyR and IP3R were also inhibited by LEV. Specifically, the RyR-induced release was inhibited by 10 μM LEV, whereas the IP3R-induced release was inhibited by 100 μM LEV, but not by 10 or 30 μM LEV. The above results suggest that LEV has little effect on the components of normal synaptic transmission but selectively inhibits transmission induced by neuronal hyperactivation. Thus, the mechanisms of the antiepileptic and neuroprotective actions of LEV seem to be mediated, at least in part, through the combination of these two inhibitory effects on depolarization-induced and CICR-associated neurotransmitter releases. Copyright © 2012. Published by Elsevier Ireland Ltd.

  9. Inhibition of ethylene production by putrescine alleviates aluminium-induced root inhibition in wheat plants

    Science.gov (United States)

    Yu, Yan; Jin, Chongwei; Sun, Chengliang; Wang, Jinghong; Ye, Yiquan; Zhou, Weiwei; Lu, Lingli; Lin, Xianyong

    2016-01-01

    Inhibition of root elongation is one of the most distinct symptoms of aluminium (Al) toxicity. Although putrescine (Put) has been identified as an important signaling molecule involved in Al tolerance, it is yet unknown how Put mitigates Al-induced root inhibition. Here, the possible mechanism was investigated by using two wheat genotypes differing in Al resistance: Al-tolerant Xi Aimai-1 and Al-sensitive Yangmai-5. Aluminium caused more root inhibition in Yangmai-5 and increased ethylene production at the root apices compared to Xi Aimai-1, whereas the effects were significantly reversed by ethylene biosynthesis inhibitors. The simultaneous exposure of wheat seedlings to Al and ethylene donor, ethephon, or ethylene biosynthesis precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), increased ethylene production and aggravated root inhibition, which was more pronounced in Xi Aimai-1. In contrast, Put treatment decreased ethylene production and alleviated Al-induced root inhibition in both genotypes, and the effects were more conspicuous in Yangmai-5. Furthermore, our results indicated that Al-induced ethylene production was mediated by ACC synthase (ACS) and ACC oxidase, and that Put decreased ethylene production by inhibiting ACS. Altogether, these findings indicate that ethylene is involved in Al-induced root inhibition and this process could be alleviated by Put through inhibiting ACS activity. PMID:26744061

  10. Inhibition of ethylene production by putrescine alleviates aluminium-induced root inhibition in wheat plants.

    Science.gov (United States)

    Yu, Yan; Jin, Chongwei; Sun, Chengliang; Wang, Jinghong; Ye, Yiquan; Zhou, Weiwei; Lu, Lingli; Lin, Xianyong

    2016-01-08

    Inhibition of root elongation is one of the most distinct symptoms of aluminium (Al) toxicity. Although putrescine (Put) has been identified as an important signaling molecule involved in Al tolerance, it is yet unknown how Put mitigates Al-induced root inhibition. Here, the possible mechanism was investigated by using two wheat genotypes differing in Al resistance: Al-tolerant Xi Aimai-1 and Al-sensitive Yangmai-5. Aluminium caused more root inhibition in Yangmai-5 and increased ethylene production at the root apices compared to Xi Aimai-1, whereas the effects were significantly reversed by ethylene biosynthesis inhibitors. The simultaneous exposure of wheat seedlings to Al and ethylene donor, ethephon, or ethylene biosynthesis precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), increased ethylene production and aggravated root inhibition, which was more pronounced in Xi Aimai-1. In contrast, Put treatment decreased ethylene production and alleviated Al-induced root inhibition in both genotypes, and the effects were more conspicuous in Yangmai-5. Furthermore, our results indicated that Al-induced ethylene production was mediated by ACC synthase (ACS) and ACC oxidase, and that Put decreased ethylene production by inhibiting ACS. Altogether, these findings indicate that ethylene is involved in Al-induced root inhibition and this process could be alleviated by Put through inhibiting ACS activity.

  11. The role of (dis)inhibition in creativity: decreased inhibition improves idea generation.

    Science.gov (United States)

    Radel, Rémi; Davranche, Karen; Fournier, Marion; Dietrich, Arne

    2015-01-01

    There is now a large body of evidence showing that many different conditions related to impaired fronto-executive functioning are associated with the enhancement of some types of creativity. In this paper, we pursue the possibility that the central mechanism associated with this effect might be a reduced capacity to exert inhibition. We tested this hypothesis by exhausting the inhibition efficiency through prolonged and intensive practice of either the Simon or the Eriksen Flanker task. Performance on another inhibition task indicated that only the cognitive resources for inhibition of participants facing high inhibition demands were impaired. Subsequent creativity tests revealed that exposure to high inhibition demands led to enhanced fluency in a divergent thinking task (Alternate Uses Task), but no such changes occurred in a convergent task (Remote Associate Task; studies 1a and 1b). The same manipulation also led to a hyper-priming effect for weakly related primes in a Lexical Decision Task (Study 2). Together, these findings suggest that inhibition selectively affects some types of creative processes and that, when resources for inhibition are lacking, the frequency and the originality of ideas was facilitated. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Mapuche herbal medicine inhibits blood platelet aggregation.

    Science.gov (United States)

    Falkenberg, Susan Skanderup; Tarnow, Inge; Guzman, Alfonso; Mølgaard, Per; Simonsen, Henrik Toft

    2012-01-01

    12 plant species traditionally used by the Mapuche people in Chile to treat wounds and inflammations have been evaluated for their direct blood platelet inhibition. Seven of the 12 tested plant species showed platelet inhibitory effect in sheep blood, and four of these were also able to inhibit the ADP- (5.0 μM) and collagen- (2.0 μg/mL) induced aggregations in human blood. These four species in respective extracts (in brackets) were Blechnum chilense (MeOH), Luma apiculata (H(2)O), Amomyrtus luma (DCM : MeOH 1 : 1) and Cestrum parqui (DCM : MeOH 1 : 1). The platelet aggregating inhibitory effects of A. luma (DCM : MeOH 1 : 1), and L. apiculata (H(2)O) were substantial and confirmed by inhibition of platelet surface activation markers.

  13. Inhibition of aluminum corrosion using Opuntia extract

    Energy Technology Data Exchange (ETDEWEB)

    El-Etre, A.Y

    2003-11-01

    The inhibitive action of the mucilage extracted from the modified stems of prickly pears, toward acid corrosion of aluminum, is tested using weight loss, thermometry, hydrogen evolution and polarization techniques. It was found that the extract acts as a good corrosion inhibitor for aluminum corrosion in 2.0 M HCl solution. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm. It was found that the adsorption of the extract on aluminum surface is a spontaneous process. The inhibition efficiency (IE) increases as the extract concentration is increased. The effect of temperature on the IE was studied. It was found that the presence of extract increases the activation energy of the corrosion reaction. Moreover, the thermodynamic parameters of the adsorption process were calculated. It was found also that the Opuntia extract provides a good protection to aluminum against pitting corrosion in chloride ion containing solutions.

  14. The ammonium sulfate inhibition of human angiogenin.

    Science.gov (United States)

    Chatzileontiadou, Demetra S M; Tsirkone, Vicky G; Dossi, Kyriaki; Kassouni, Aikaterini G; Liggri, Panagiota G V; Kantsadi, Anastassia L; Stravodimos, George A; Balatsos, Nikolaos A A; Skamnaki, Vassiliki T; Leonidas, Demetres D

    2016-09-01

    In this study, we investigate the inhibition of human angiogenin by ammonium sulfate. The inhibitory potency of ammonium sulfate for human angiogenin (IC50 = 123.5 ± 14.9 mm) is comparable to that previously reported for RNase A (119.0 ± 6.5 mm) and RNase 2 (95.7 ± 9.3 mm). However, analysis of two X-ray crystal structures of human angiogenin in complex with sulfate anions (in acidic and basic pH environments, respectively) indicates an entirely distinct mechanism of inhibition. While ammonium sulfate inhibits the ribonucleolytic activity of RNase A and RNase 2 by binding to the active site of these enzymes, sulfate anions bind only to peripheral substrate anion-binding subsites of human angiogenin, and not to the active site. © 2016 Federation of European Biochemical Societies.

  15. The inhibition of monoamine oxidase by esomeprazole.

    Science.gov (United States)

    Petzer, A; Pienaar, A; Petzer, J P

    2013-09-01

    Virtual screening of a library of drugs has suggested that esomeprazole, the S-enantiomer of omeprazole, may possess binding affinities for the active sites of the monoamine oxidase (MAO) A and B enzymes. Based on this finding, the current study examines the MAO inhibitory properties of esomeprazole. Using recombinant human MAO-A and MAO-B, IC50 values for the inhibition of these enzymes by esomeprazole were experimentally determined. To examine the reversibility of MAO inhibition by esomeprazole, the recoveries of the enzymatic activities after dilution of the enzyme-inhibitor complexes were evaluated. In addition, reversibility of inhibition was also examined by measuring the recoveries of enzyme activities after dialysis of enzyme-inhibitor mixtures. Lineweaver-Burk plots were constructed to evaluate the mode of MAO inhibition and to measure Ki values. The results document that esomeprazole inhibits both MAO-A and MAO-B with IC50 values of 23 µM and 48 µM, respectively. The interactions of esomeprazole with MAO-A and MAO-B are reversible and most likely competitive with Ki values for the inhibition of the respective enzymes of 8.99 µM and 31.7 µM. Considering the available pharmacokinetic data and typical therapeutic doses of esomeprazole, these inhibitory potencies are unlikely to be of pharmacological relevance in humans. The MAO inhibitory effects of esomeprazole should however be taken into consideration when using this drug in animal experiments where higher doses are often administered. © Georg Thieme Verlag KG Stuttgart · New York.

  16. Sprout inhibition in roots, tubers and bulbs

    International Nuclear Information System (INIS)

    Luna C, P.C.

    1992-05-01

    The treatment with ionizing radiations to low dose impedes that appear sprouts in the tubers (potatoes); bulbs (onion and garlic) and in roots like the ginger and the yucca. The purpose is to inhibit the germination during the process of manipulation and storage, and this way to avoid the lost ones post crop of these products. The radiation dose required to inhibit the germination goes to depend of: the development conditions, the differences of variety, of the storage state of the bulbs and the conditions of cured and storage. (Author)

  17. Enzyme inhibition activities of Andrachne cardifolia Muell.

    Science.gov (United States)

    Ahmad, Bashir; Shah, S M Hassan; Bashir, Shumaila; Shah, Jehandar

    2007-04-01

    The crude methanolic extract and various fractions of Andrachne cardifolia Muell, including chloroform, ethyl acetate and n-butanol fractions were subjected to in vitro enzyme inhibition activity against acetylcholinesterase, butyrylcholinesterase, lipoxygenase and urease enzymes. A significant enzyme inhibition activity (40-89%) was shown by the crude methanolic extract and its fractions against lipoxygenase, while low to significant activity (40-71%) against butyrylcholinesterase. The crude methanolic extract and its various fractions demonstrated poor to significant activity (25-73%) against acetylcholinesterase and no activity against urease.

  18. Many Putative Endocrine Disruptors Inhibit Prostaglandin Synthesis

    DEFF Research Database (Denmark)

    Kristensen, David M.; Skalkam, Maria L.; Audouze, Karine Marie Laure

    2011-01-01

    Background: Prostaglandins (PGs) play key roles in development and maintenance of homeostasis of the adult body. Despite these important roles, it remains unclear whether the PG pathway is a target for endocrine disruption. However, several known endocrine disrupting compounds (EDCs) share a high...... of endocrine disruption. Results: We found that many known EDCs inhibit the PG pathway in a mouse Sertoli cell line and in human primary mast cells. The EDCs also reduced PG synthesis in ex vivo rat testis and it was correlated with a reduced testosterone production. The inhibition of PG synthesis occurs...

  19. Inhibition of soybean urease by triketone oximes.

    Science.gov (United States)

    Tarun, E I; Rubinov, D B; Metelitza, D I

    2004-12-01

    Competitive inhibition of soybean urease by 15 triketone oximes has been studied at 36 degrees C in aqueous solution (pH 4.95). The studied oximes are supposed chelators for the nickel atom in the urease metallocenter. The inhibition constants of urea hydrolysis (K(i)) varied in the range 2.7-248 microM depending on the oxime structure. Analysis of this dependency demonstrates that the optimal inhibitor is the one containing carbonyl group in position 1 of the cycle, the ethoxyimino group and alkyl residue in the substituent in position 2, as well as the methoxycarbonyl group in position 4 of the cycle.

  20. Peptide inhibition of human cytomegalovirus infection

    Directory of Open Access Journals (Sweden)

    Morris Cindy A

    2011-02-01

    Full Text Available Abstract Background Human cytomegalovirus (HCMV is the most prevalent congenital viral infection in the United States and Europe causing significant morbidity and mortality to both mother and child. HCMV is also an opportunistic pathogen in immunocompromised individuals, including human immunodeficiency virus (HIV- infected patients with AIDS, and solid organ and allogeneic stem cell transplantation recipients. Current treatments for HCMV-associated diseases are insufficient due to the emergence of drug-induced resistance and cytotoxicity, necessitating novel approaches to limit HCMV infection. The aim of this study was to develop therapeutic peptides targeting glycoprotein B (gB, a major glycoprotein of HCMV that is highly conserved across the Herpesviridae family, that specifically inhibit fusion of the viral envelope with the host cell membrane preventing HCMV entry and infection. Results Using the Wimley-White Interfacial Hydrophobicity Scale (WWIHS, several regions within gB were identified that display a high potential to interact with lipid bilayers of cell membranes and hydrophobic surfaces within proteins. The ability of synthetic peptides analogous to WWIHS-positive sequences of HCMV gB to inhibit viral infectivity was evaluated. Human foreskin fibroblasts (HFF were infected with the Towne-GFP strain of HCMV (0.5 MOI, preincubated with peptides at a range of concentrations (78 nm to 100 μM, and GFP-positive cells were visualized 48 hours post-infection by fluorescence microscopy and analyzed quantitatively by flow cytometry. Peptides that inhibited HCMV infection demonstrated different inhibitory concentration curves indicating that each peptide possesses distinct biophysical properties. Peptide 174-200 showed 80% inhibition of viral infection at a concentration of 100 μM, and 51% and 62% inhibition at concentrations of 5 μM and 2.5 μM, respectively. Peptide 233-263 inhibited infection by 97% and 92% at concentrations of 100

  1. Salinomycin, a polyether ionophoric antibiotic, inhibits adipogenesis

    International Nuclear Information System (INIS)

    Szkudlarek-Mikho, Maria; Saunders, Rudel A.; Yap, Sook Fan; Ngeow, Yun Fong; Chin, Khew-Voon

    2012-01-01

    Highlights: ► Salinomycin inhibits preadipocyte differentiation into adipocytes. ► Salinomycin inhibits transcriptional regulation of adipogenesis. ► Pharmacological effects of salinomycin suggest toxicity in cancer therapy. -- Abstract: The polyether ionophoric antibiotics including monensin, salinomycin, and narasin, are widely used in veterinary medicine and as food additives and growth promoters in animal husbandry including poultry farming. Their effects on human health, however, are not fully understood. Recent studies showed that salinomycin is a cancer stem cell inhibitor. Since poultry consumption has risen sharply in the last three decades, we asked whether the consumption of meat tainted with growth promoting antibiotics might have effects on adipose cells. We showed in this report that the ionophoric antibiotics inhibit the differentiation of preadipocytes into adipocytes. The block of differentiation is not due to the induction of apoptosis nor the inhibition of cell proliferation. In addition, salinomycin also suppresses the transcriptional activity of the CCAAT/enhancer binding proteins and the peroxisome proliferator-activated receptor γ. These results suggest that the ionophoric antibiotics can be exploited as novel anti-obesity therapeutics and as pharmacological probes for the study of adipose biology. Further, the pharmacological effects of salinomycin could be a harbinger of its toxicity on the adipose tissue and other susceptible target cells in cancer therapy.

  2. Nickel Inhibits Mitochondrial Fatty Acid Oxidation

    Science.gov (United States)

    Uppala, Radha; McKinney, Richard W.; Brant, Kelly A.; Fabisiak, James P.; Goetzman, Eric S.

    2015-01-01

    Nickel exposure is associated with changes in cellular energy metabolism which may contribute to its carcinogenic properties. Here, we demonstrate that nickel strongly represses mitochondrial fatty acid oxidation—the pathway by which fatty acids are catabolized for energy—in both primary human lung fibroblasts and mouse embryonic fibroblasts. At the concentrations used, nickel suppresses fatty acid oxidation without globally suppressing mitochondrial function as evidenced by increased glucose oxidation to CO2. Pre-treatment with L-carnitine, previously shown to prevent nickel-induced mitochondrial dysfunction in neuroblastoma cells, did not prevent the inhibition of fatty acid oxidation. The effect of nickel on fatty acid oxidation occurred only with prolonged exposure (>5 hr), suggesting that direct inhibition of the active sites of metabolic enzymes is not the mechanism of action. Nickel is a known hypoxia-mimetic that activates hypoxia inducible factor-1α (HIF1α). Nickel-induced inhibition of fatty acid oxidation was blunted in HIF1α knockout fibroblasts, implicating HIF1α as one contributor to the mechanism. Additionally, nickel down-regulated the protein levels of the key fatty acid oxidation enzyme very long-chain acyl-CoA dehydrogenase (VLCAD) in a dose-dependent fashion. In conclusion, inhibition of fatty acid oxidation by nickel, concurrent with increased glucose metabolism, represents a form of metabolic reprogramming that may contribute to nickel-induced carcinogenesis. PMID:26051273

  3. Inhibition of serum naphthylamidases by atopic allergens

    NARCIS (Netherlands)

    Berrens, L.

    1968-01-01

    Human serum hydrolyses the 2-naphthylamides of -lysine and -arginine. The enzymatic activity of the serum naphthylamidases is inhibited by atopic allergens and by protein-sugar conjugates carrying 1-deoxy-2-ketose residues attached to the -amino groups of lysine residues in their peptide moieties.

  4. Salinomycin, a polyether ionophoric antibiotic, inhibits adipogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Szkudlarek-Mikho, Maria; Saunders, Rudel A. [Department of Medicine, Biochemistry and Cancer Biology, Center for Diabetes and Endocrine Research, College of Medicine, University of Toledo, Toledo, OH 43614 (United States); Yap, Sook Fan [Faculty of Medicine and Health Sciences, Department of Pre-Clinical Sciences, University of Tunku Abdul Rahman (Malaysia); Ngeow, Yun Fong [Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603 (Malaysia); Chin, Khew-Voon, E-mail: khew-voon.chin@utoledo.edu [Department of Medicine, Biochemistry and Cancer Biology, Center for Diabetes and Endocrine Research, College of Medicine, University of Toledo, Toledo, OH 43614 (United States)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer Salinomycin inhibits preadipocyte differentiation into adipocytes. Black-Right-Pointing-Pointer Salinomycin inhibits transcriptional regulation of adipogenesis. Black-Right-Pointing-Pointer Pharmacological effects of salinomycin suggest toxicity in cancer therapy. -- Abstract: The polyether ionophoric antibiotics including monensin, salinomycin, and narasin, are widely used in veterinary medicine and as food additives and growth promoters in animal husbandry including poultry farming. Their effects on human health, however, are not fully understood. Recent studies showed that salinomycin is a cancer stem cell inhibitor. Since poultry consumption has risen sharply in the last three decades, we asked whether the consumption of meat tainted with growth promoting antibiotics might have effects on adipose cells. We showed in this report that the ionophoric antibiotics inhibit the differentiation of preadipocytes into adipocytes. The block of differentiation is not due to the induction of apoptosis nor the inhibition of cell proliferation. In addition, salinomycin also suppresses the transcriptional activity of the CCAAT/enhancer binding proteins and the peroxisome proliferator-activated receptor {gamma}. These results suggest that the ionophoric antibiotics can be exploited as novel anti-obesity therapeutics and as pharmacological probes for the study of adipose biology. Further, the pharmacological effects of salinomycin could be a harbinger of its toxicity on the adipose tissue and other susceptible target cells in cancer therapy.

  5. Probenazole treatment inhibits anthocyanins biosynthesis via ...

    African Journals Online (AJOL)

    It has been found that anthocyanins were accumulated in Arabidopsis under drought or salt stress. In this study, such accumulation was found to be inhibited by external applied probenazole (3-allyloxy-1, 2-benzisothiazole-1,1-dioxide, PBZ), which is the active ingredient in oryzemate used for the protection of rice from ...

  6. Insulin inhibits tissue factor expression in monocytes

    NARCIS (Netherlands)

    Gerrits, A. J.; Koekman, C. A.; Yildirim, C.; Nieuwland, R.; Akkerman, J. W. N.

    2009-01-01

    Summary Objectives: Platelets from healthy subjects are inhibited by insulin but type 2 diabetes mellitus (T2DM) platelets have become insulin-resistant which might explain their hyperactivity. In the present study we investigated whether monocytes are responsive to insulin. Methods and Results:

  7. Undecylenic Acid Inhibits Morphogenesis of Candida albicans

    OpenAIRE

    McLain, Nealoo; Ascanio, Rhoda; Baker, Carol; Strohaver, Robert A.; Dolan, Joseph W.

    2000-01-01

    Resilient liners are frequently used to treat denture stomatitis, a condition often associated with Candida albicans infections. Of 10 liners tested, 2 were found to inhibit the switch from the yeast form to hyphae and a third was found to stimulate this switch. The inhibitor was determined to be undecylenic acid.

  8. Undecylenic acid inhibits morphogenesis of Candida albicans.

    Science.gov (United States)

    McLain, N; Ascanio, R; Baker, C; Strohaver, R A; Dolan, J W

    2000-10-01

    Resilient liners are frequently used to treat denture stomatitis, a condition often associated with Candida albicans infections. Of 10 liners tested, 2 were found to inhibit the switch from the yeast form to hyphae and a third was found to stimulate this switch. The inhibitor was determined to be undecylenic acid.

  9. Illustrating Enzyme Inhibition Using Gibbs Energy Profiles

    Science.gov (United States)

    Bearne, Stephen L.

    2012-01-01

    Gibbs energy profiles have great utility as teaching and learning tools because they present students with a visual representation of the energy changes that occur during enzyme catalysis. Unfortunately, most textbooks divorce discussions of traditional kinetic topics, such as enzyme inhibition, from discussions of these same topics in terms of…

  10. Inhibition of Corneal Neovascularization by Hydrazinocurcumin

    African Journals Online (AJOL)

    This article previously published in Volume 15 Issue 2 of this journal in February 2016 has been retracted in line with the guidelines from the Committee on Publication Ethics (COPE, http://publicationethics.org/resources/guidelines). Retracted: Zhan W, Zhu J, Zhang Y. Inhibition of corneal neovascularization by ...

  11. Retracted: Inhibition of Corneal Neovascularization by ...

    African Journals Online (AJOL)

    This article previously published in Volume 15 Issue 2 of this journal in February 2016 has been retracted in line with the guidelines from the Committee on Publication Ethics (COPE, http://publicationethics.org/resources/guidelines). Retracted: Zhan W, Zhu J, Zhang Y. Inhibition of corneal neovascularization by ...

  12. Type IA topoisomerase inhibition by clamp closure.

    Science.gov (United States)

    Leelaram, Majety Naga; Bhat, Anuradha Gopal; Godbole, Adwait Anand; Bhat, Rajeshwari Subray; Manjunath, Ramanathapuram; Nagaraja, Valakunja

    2013-08-01

    Bacterial DNA topoisomerase I (topoI) catalyzes relaxation of negatively supercoiled DNA. The enzyme alters DNA topology through protein-operated DNA gate, switching between open and closed conformations during its reaction. We describe the mechanism of inhibition of Mycobacterium smegmatis and Mycobacterium tuberculosis topoI by monoclonal antibodies (mAbs) that bind with high affinity and inhibit at 10-50 nM concentration. Unlike other inhibitors of topoisomerases, the mAbs inhibited several steps of relaxation reaction, namely DNA binding, cleavage, strand passage, and enzyme-DNA dissociation. The enhanced religation of the cleaved DNA in presence of the mAb indicated closing of the enzyme DNA gate. The formation of enzyme-DNA heterocatenane in the presence of the mAbs as a result of closing the gate could be inferred by the salt resistance of the complex, visualized by atomic force microscopy and confirmed by fluorescence measurements. Locking the enzyme-DNA complex as a closed clamp restricted the movements of the DNA gate, affecting all of the major steps of the relaxation reaction. Enzyme trapped on DNA in closed clamp conformation formed roadblock for the elongating DNA polymerase. The unusual multistep inhibition of mycobacterial topoisomerases may facilitate lead molecule development, and the mAbs would also serve as valuable tools to probe the enzyme mechanism.

  13. Optimal decision making in neural inhibition models

    NARCIS (Netherlands)

    van Ravenzwaaij, D.; van der Maas, H.L.J.; Wagenmakers, E.-J.

    2012-01-01

    In their influential Psychological Review article, Bogacz, Brown, Moehlis, Holmes, and Cohen (2006) discussed optimal decision making as accomplished by the drift diffusion model (DDM). The authors showed that neural inhibition models, such as the leaky competing accumulator model (LCA) and the

  14. Inhibited interferon production after space flight

    Science.gov (United States)

    Sonnenfeld, G.; Gould, C. L.; Williams, J.; Mandel, A. D.

    1988-01-01

    Several studies have been performed in our laboratories indicating that interferon production may be impaired in rodents after space flight. Using an antiorthostatic suspension model that simulates some of the effects of microgravity seen during space flight, we have shown that interferon-alpha/beta production was inhibited. The inhibition was not due solely to the stress of suspension. The inhibited interferon production was transient, as suspended animals returned to normal caging recovered the ability to produce interferon. Antiorthostatic suspension of mice also resulted in a loss of resistance to infection with the diabetogenic strain of encephalomyocarditis virus, which correlated with the drop in interferon production. In rats flown in US Space Shuttle mission SL-3, interferon-gamma production was inhibited severely when spleen cells were challenged with concanavalin-A upon return to earth. In contrast, interleukin-3 production by these cells was normal. These results suggest that immune responses may be altered after antiorthostatic modeling or space flight, and the resistance to viral infections may be especially affected.

  15. Inhibiting Translation One Protein at a Time.

    Science.gov (United States)

    Disney, Matthew D

    2017-06-01

    Historically, translational inhibitors have been confined to anti-bacterials that globally affect translation. Lintner et al. demonstrate that small molecules can specifically inhibit translation of a single disease-associated protein by stalling the ribosome's nascent chain [1], opening up a new therapeutic strategy for 'undruggable' proteins. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Inhibition of barley grain germination by light

    NARCIS (Netherlands)

    Roth-Bejerano, N.; Meulen, R.M. van der; Wang, M.

    1996-01-01

    Intact grains of barley (Hordeum distichum cv. Triumph) germinated rapidly in the dark or when exposed to brief daily light breaks in the temperature range 15-25°C, although germination proceeded less rapidly at low temperatures. Prolonged illumination (16 h/day) or continuous light inhibited

  17. Inhibiting Intuitive Thinking in Mathematics Education

    Science.gov (United States)

    Thomas, Michael O. J.

    2015-01-01

    The papers in this issue describe recent collaborative research into the role of inhibition of intuitive thinking in mathematics education. This commentary reflects on this research from a mathematics education perspective and draws attention to some of the challenges that arise in collaboration between research fields with different cultures,…

  18. Inhibition of Lipopolysaccharide-Induced Neuroinflammatory Events ...

    African Journals Online (AJOL)

    mL) with an IC50 value of 0.08 μg/mL. Conclusion: Data from this study indicate that CCP extract attenuates neuroinflammatory responses in. LPS-activated BV-2 microglia by inhibiting excessive production of pro-inflammatory mediators such ...

  19. Neural synchrony during response production and inhibition.

    Directory of Open Access Journals (Sweden)

    Viktor Müller

    Full Text Available Inhibition of irrelevant information (conflict monitoring and/or of prepotent actions is an essential component of adaptive self-organized behavior. Neural dynamics underlying these functions has been studied in humans using event-related brain potentials (ERPs elicited in Go/NoGo tasks that require a speeded motor response to the Go stimuli and withholding a prepotent response when a NoGo stimulus is presented. However, averaged ERP waveforms provide only limited information about the neuronal mechanisms underlying stimulus processing, motor preparation, and response production or inhibition. In this study, we examine the cortical representation of conflict monitoring and response inhibition using time-frequency analysis of electroencephalographic (EEG recordings during continuous performance Go/NoGo task in 50 young adult females. We hypothesized that response inhibition would be associated with a transient boost in both temporal and spatial synchronization of prefrontal cortical activity, consistent with the role of the anterior cingulate and lateral prefrontal cortices in cognitive control. Overall, phase synchronization across trials measured by Phase Locking Index and phase synchronization between electrode sites measured by Phase Coherence were the highest in the Go and NoGo conditions, intermediate in the Warning condition, and the lowest under Neutral condition. The NoGo condition was characterized by significantly higher fronto-central synchronization in the 300-600 ms window, whereas in the Go condition, delta- and theta-band synchronization was higher in centro-parietal regions in the first 300 ms after the stimulus onset. The present findings suggest that response production and inhibition is supported by dynamic functional networks characterized by distinct patterns of temporal and spatial synchronization of brain oscillations.

  20. WEE1 inhibition sensitizes osteosarcoma to radiotherapy

    International Nuclear Information System (INIS)

    PosthumaDeBoer, Jantine; Würdinger, Thomas; Graat, Harm CA; Beusechem, Victor W van; Helder, Marco N; Royen, Barend J van; Kaspers, Gertjan JL

    2011-01-01

    The use of radiotherapy in osteosarcoma (OS) is controversial due to its radioresistance. OS patients currently treated with radiotherapy generally are inoperable, have painful skeletal metastases, refuse surgery or have undergone an intralesional resection of the primary tumor. After irradiation-induced DNA damage, OS cells sustain a prolonged G 2 cell cycle checkpoint arrest allowing DNA repair and evasion of cell death. Inhibition of WEE1 kinase leads to abrogation of the G 2 arrest and could sensitize OS cells to irradiation induced cell death. WEE1 expression in OS was investigated by gene-expression data analysis and immunohistochemistry of tumor samples. WEE1 expression in OS cell lines and human osteoblasts was investigated by Western blot. The effect of WEE1 inhibition on the radiosensitivity of OS cells was assessed by cell viability and caspase activation analyses after combination treatment. The presence of DNA damage was visualized using immunofluorescence microscopy. Cell cycle effects were investigated by flow cytometry and WEE1 kinase regulation was analyzed by Western blot. WEE1 expression is found in the majority of tested OS tissue samples. Small molecule drug PD0166285 inhibits WEE1 kinase activity. In the presence of WEE1-inhibitor, irradiated cells fail to repair their damaged DNA, and show higher levels of caspase activation. The inhibition of WEE1 effectively abrogates the irradiation-induced G 2 arrest in OS cells, forcing the cells into premature, catastrophic mitosis, thus enhancing cell death after irradiation treatment. We show that PD0166285, a small molecule WEE1 kinase inhibitor, can abrogate the G 2 checkpoint in OS cells, pushing them into mitotic catastrophe and thus sensitizing OS cells to irradiation-induced cell death. This suggests that WEE1 inhibition may be a promising strategy to enhance the radiotherapy effect in patients with OS

  1. Polysulfonate suramin inhibits Zika virus infection.

    Science.gov (United States)

    Tan, Chee Wah; Sam, I-Ching; Chong, Wei Lim; Lee, Vannajan Sanghiran; Chan, Yoke Fun

    2017-07-01

    Zika virus (ZIKV) is an arthropod-borne flavivirus that causes newborn microcephaly and Guillian-Barré syndrome in adults. No therapeutics are available to treat ZIKV infection or other flaviviruses. In this study, we explored the inhibitory effect of glycosaminoglycans and analogues against ZIKV infection. Highly sulfated heparin, dextran sulfate and suramin significantly inhibited ZIKV infection in Vero cells. De-sulfated heparin analogues lose inhibitory effect, implying that sulfonate groups are critical for viral inhibition. Suramin, an FDA-approved anti-parasitic drug, inhibits ZIKV infection with 3-5 log 10  PFU viral reduction with IC 50 value of ∼2.5-5 μg/ml (1.93 μM-3.85 μM). A time-of-drug-addition study revealed that suramin remains potent even when administrated at 1-24 hpi. Suramin inhibits ZIKV infection by preventing viral adsorption, entry and replication. Molecular dynamics simulation revealed stronger interaction of suramin with ZIKV NS3 helicase than with the envelope protein. Suramin warrants further investigation as a potential antiviral candidate for ZIKV infection. Heparan sulfate (HS) is a cellular attachment receptor for multiple flaviviruses. However, no direct ZIKV-heparin interaction was observed in heparin-binding analysis, and downregulate or removal of cellular HS with sodium chlorate or heparinase I/III did not inhibit ZIKV infection. This indicates that cell surface HS is not utilized by ZIKV as an attachment receptor. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Equol inhibits growth, induces atresia, and inhibits steroidogenesis of mouse antral follicles in vitro

    International Nuclear Information System (INIS)

    Mahalingam, Sharada; Gao, Liying; Gonnering, Marni; Helferich, William; Flaws, Jodi A.

    2016-01-01

    Equol is a non-steroidal estrogen metabolite produced by microbial conversion of daidzein, a major soy isoflavone, in the gut of some humans and many animal species. Isoflavones and their metabolites can affect endogenous estradiol production, action, and metabolism, potentially influencing ovarian follicle function. However, no studies have examined the effects of equol on intact ovarian antral follicles, which are responsible for sex steroid synthesis and further development into ovulatory follicles. Thus, the present study tested the hypothesis that equol inhibits antral follicle growth, increases follicle atresia, and inhibits steroidogenesis in the adult mouse ovary. To test this hypothesis, antral follicles isolated from adult CD-1 mice were cultured with vehicle control (dimethyl sulfoxide; DMSO) or equol (600 nM, 6 μM, 36 μM, and 100 μM) for 48 and 96 h. Every 24 h, follicle diameters were measured to monitor growth. At 48 and 96 h, the culture medium was subjected to measurement of hormone levels, and the cultured follicles were subjected to gene expression analysis. Additionally, follicles were histologically evaluated for signs of atresia after 96 h of culture. The results indicate that equol (100 μM) inhibited follicle growth, altered the mRNA levels of bcl2-associated X protein and B cell leukemia/lymphoma 2, and induced follicle atresia. Further, equol decreased the levels of estradiol, testosterone, androstenedione, and progesterone, and it decreased mRNA levels of cholesterol side-chain cleavage, steroid 17-α-hydroxalase, and aromatase. Collectively, these data indicate that equol inhibits growth, increases atresia, and inhibits steroidogenesis of cultured mouse antral follicles. - Highlights: • Equol exposure inhibits antral follicle growth. • Equol exposure increases follicle atresia. • Equol exposure inhibits sex steroid hormone levels. • Equol exposure inhibits mRNA levels of certain steroidogenic enzymes.

  3. Proactive modulation of long-interval intracortical inhibition during response inhibition

    Science.gov (United States)

    Cowie, Matthew J.; MacDonald, Hayley J.; Cirillo, John

    2016-01-01

    Daily activities often require sudden cancellation of preplanned movement, termed response inhibition. When only a subcomponent of a whole response must be suppressed (required here on Partial trials), the ensuing component is markedly delayed. The neural mechanisms underlying partial response inhibition remain unclear. We hypothesized that Partial trials would be associated with nonselective corticomotor suppression and that GABAB receptor-mediated inhibition within primary motor cortex might be responsible for the nonselective corticomotor suppression contributing to Partial trial response delays. Sixteen right-handed participants performed a bimanual anticipatory response inhibition task while single- and paired-pulse transcranial magnetic stimulation was delivered to elicit motor evoked potentials in the left first dorsal interosseous muscle. Lift times, amplitude of motor evoked potentials, and long-interval intracortical inhibition were examined across the different trial types (Go, Stop-Left, Stop-Right, Stop-Both). Go trials produced a tight distribution of lift times around the target, whereas those during Partial trials (Stop-Left and Stop-Right) were substantially delayed. The modulation of motor evoked potential amplitude during Stop-Right trials reflected anticipation, suppression, and subsequent reinitiation of movement. Importantly, suppression was present across all Stop trial types, indicative of a “default” nonselective inhibitory process. Compared with blocks containing only Go trials, inhibition increased when Stop trials were introduced but did not differ between trial types. The amount of inhibition was positively correlated with lift times during Stop-Right trials. Tonic levels of inhibition appear to be proactively modulated by task context and influence the speed at which unimanual responses occur after a nonselective “brake” is applied. PMID:27281744

  4. Theobromine inhibits sensory nerve activation and cough.

    Science.gov (United States)

    Usmani, Omar S; Belvisi, Maria G; Patel, Hema J; Crispino, Natascia; Birrell, Mark A; Korbonits, Márta; Korbonits, Dezso; Barnes, Peter J

    2005-02-01

    Cough is a common and protective reflex, but persistent coughing is debilitating and impairs quality of life. Antitussive treatment using opioids is limited by unacceptable side effects, and there is a great need for more effective remedies. The present study demonstrates that theobromine, a methylxanthine derivative present in cocoa, effectively inhibits citric acid-induced cough in guinea-pigs in vivo. Furthermore, in a randomized, double-blind, placebo-controlled study in man, theobromine suppresses capsaicin-induced cough with no adverse effects. We also demonstrate that theobromine directly inhibits capsaicin-induced sensory nerve depolarization of guinea-pig and human vagus nerve suggestive of an inhibitory effect on afferent nerve activation. These data indicate the actions of theobromine appear to be peripherally mediated. We conclude theobromine is a novel and promising treatment, which may form the basis for a new class of antitussive drugs.

  5. Direct renin inhibition in chronic kidney disease

    DEFF Research Database (Denmark)

    Persson, Frederik; Rossing, Peter; Parving, Hans-Henrik

    2013-01-01

    that renin inhibition could hold potential for improved treatment in patients with chronic kidney disease, with diabetic nephropathy as an obvious group of patients to investigate, as the activity of the renin-angiotensin-aldosterone system is enhanced in these patients and as there is an unmet need...... early as a beneficial effect was unlikely and there was an increased frequency of side effects. Also in non-diabetic kidney disease a few intervention studies have been carried out, but there is no ongoing hard outcome study. In this review we provide the current evidence for renin inhibition in chronic...... kidney disease by reporting of the studies published so far as well as perspective on the future possibilites....

  6. Methamphetamine inhibits antigen processing, presentation, and phagocytosis.

    Directory of Open Access Journals (Sweden)

    Zsolt Tallóczy

    2008-02-01

    Full Text Available Methamphetamine (Meth is abused by over 35 million people worldwide. Chronic Meth abuse may be particularly devastating in individuals who engage in unprotected sex with multiple partners because it is associated with a 2-fold higher risk for obtaining HIV and associated secondary infections. We report the first specific evidence that Meth at pharmacological concentrations exerts a direct immunosuppressive effect on dendritic cells and macrophages. As a weak base, Meth collapses the pH gradient across acidic organelles, including lysosomes and associated autophagic organelles. This in turn inhibits receptor-mediated phagocytosis of antibody-coated particles, MHC class II antigen processing by the endosomal-lysosomal pathway, and antigen presentation to splenic T cells by dendritic cells. More importantly Meth facilitates intracellular replication and inhibits intracellular killing of Candida albicans and Cryptococcus neoformans, two major AIDS-related pathogens. Meth exerts previously unreported direct immunosuppressive effects that contribute to increased risk of infection and exacerbate AIDS pathology.

  7. Inhibition of intestinal disaccharidase activity by pentoses

    DEFF Research Database (Denmark)

    Halschou-Jensen, Kia

    The current health problems regarding the obesity epidemic, development of type 2 diabetes mellitus (T2D) and cardiovascular disease are a major challenge for healthcare systems worldwide.No simple or unique cure has been documented to prevent or treat this major health problem regarding T2D...... on carbohydrate- ingesting enzymes activity in vitro and possible effects on human postprandial blood response. In paper 1 the effects of sugar beet polyphenols from molasses and the potential inhibition of sucrase activity in vitro, was investigated. Two different polyphenol-rich fractions from chromatographic...... separation of molasses from sugar beets and pure ferulic acid were tested. We found no effects of the two fractions of molasses. The pure ferulic acid indicated an inhibition of sucrase in vitr. Both in vitro and in vivo studies have investigated the effects of L-arabinose and D-xylose on carbohydrate...

  8. The Kinetics of Carrier Transport Inhibition

    DEFF Research Database (Denmark)

    Rosenberg, T.; Wilbrandt, Robert Walter

    1962-01-01

    The kinetical treatment of enzymatic carrier transports as given in previous communications has been extended to conditions of inhibition. Various possible types of inhibitors have been considered differing in the site of attack (enzyme or carrier), in the mode of action (competing...... and polyphloretinephosphate. The results of the analysis for these inhibitors indicate a substrate competitive mode of action. The effect of reversing the transport direction by interchanging the substrate concentration has been treated for the case of a non-penetrating substrate competitive inhibitor in the external medium...... with the substrate for the enzyme or the carrier or for both, competing with the carrier for the enzyme, or non-competitive) and in the ability of penetrating the membrane. Experiments are reported on the inhibition of glucose and fructose transport across the human red cell membrane by phlorizine, phloretine...

  9. Fermentation of lignocellulosic hydrolysates: Inhibition and detoxification

    Energy Technology Data Exchange (ETDEWEB)

    Palmqvist, E.

    1998-02-01

    The ethanol yield and productivity obtained during fermentation of lignocellulosic hydrolysates is decreased due to the presence of inhibiting compounds, such as weak acids, furans and phenolic compounds produced during hydrolysis. Evaluation of the effect of various biological, physical and chemical detoxification treatments by fermentation assays using Saccharomyces cerevisiae was used to characterise inhibitors. Inhibition of fermentation was decreased after removal of the non-volatile compounds, pre-fermentation by the filamentous fungus Trichoderma reesei, treatment with the lignolytic enzyme laccase, extraction with ether, and treatment with alkali. Yeast growth in lignocellulosic hydrolysates was inhibited below a certain fermentation pH, most likely due to high concentrations of undissociated weak acids. The effect of individual compounds were studied in model fermentations. Furfural is reduced to furfuryl alcohol by yeast dehydrogenases, thereby affecting the intracellular redox balance. As a result, acetaldehyde accumulated during furfural reduction, which most likely contributed to inhibition of growth. Acetic acid (10 g 1{sup -1}) and furfural (3 g 1{sup -1}) interacted antagonistically causing decreased specific growth rate, whereas no significant individual or interaction effects were detected by the lignin-derived compound 4-hydroxybenzoic acid (2 g 1{sup -1}). By maintaining a high cell mass density in the fermentor, the process was less sensitive to inhibitors affecting growth and to fluctuations in fermentation pH, and in addition the depletion rate of bioconvertible inhibitors was increased. A theoretical ethanol yield and high productivity was obtained in continuous fermentation of spruce hydrolysate when the cell mass concentration was maintained at a high level by applying cell recirculation 164 refs, 16 figs, 5 tabs

  10. Voriconazole Inhibits Melanization in Cryptococcus neoformans▿

    OpenAIRE

    Martinez, Luis R.; Ntiamoah, Patricia; Gácser, Attila; Casadevall, Arturo; Nosanchuk, Joshua D.

    2007-01-01

    Voriconazole is a triazole antifungal drug that inhibits ergosterol synthesis and has broad activity against yeast and molds. While studying the interaction of voriconazole and Cryptococcus neoformans, we noted that cells grown in the presence of subinhibitory concentrations of voriconazole reduced melanin pigmentation. We investigated this effect systematically by assessing melanin production in the presence of voriconazole, amphotericin B, caspofungin, itraconazole, and fluconazole. Only vo...

  11. Theoretical and experimental studies of thermolysin inhibition

    OpenAIRE

    Wuxiuer, Yimingjiang

    2008-01-01

    Zinc-metalloproteinases play a key role in the biosythesis and metabolism of different bioactive peptides. As a member of zinc-metalloproteinases, thermolysin has served as a model system to study the inhibition mechanism of other metalloproteinases. Inhibitors of thermolysin have considerable potential as therapeutic agents. In the present master thesis, docking calculations were performed and reported for 25 potent non-peptidal thermolysin inhibitors retrieved from literatures. Docking sof...

  12. Extinction Generates Outcome-Specific Conditioned Inhibition.

    Science.gov (United States)

    Laurent, Vincent; Chieng, Billy; Balleine, Bernard W

    2016-12-05

    Extinction involves altering a previously established predictive relationship between a cue and its outcome by repeatedly presenting that cue alone. Although it is widely accepted that extinction generates some form of inhibitory learning [1-4], direct evidence for this claim has been lacking, and the nature of the associative changes induced by extinction have, therefore, remained a matter of debate [5-8]. In the current experiments, we used a novel behavioral approach that we recently developed and that provides a direct measure of conditioned inhibition [9] to compare the influence of extinguished and non-extinguished cues on choice between goal-directed actions. Using this approach, we provide direct evidence that extinction generates outcome-specific conditioned inhibition. Furthermore, we demonstrate that this inhibitory learning is controlled by the infralimbic cortex (IL); inactivation of the IL using M4 DREADDs abolished outcome-specific inhibition and rendered the cue excitatory. Importantly, we found that context modulated this inhibition. Outside its extinction context, the cue was excitatory and functioned as a specific predictor of its previously associated outcome, biasing choice toward actions earning the same outcome. In its extinction context, however, the cue acted as a specific inhibitor and biased choice toward actions earning different outcomes. Context modulation of these excitatory and inhibitory memories was mediated by the dorsal hippocampus (HPC), suggesting that the HPC and IL act in concert to control the influence of conditioned inhibitors on choice. These findings demonstrate for the first time that extinction turns a cue into a net inhibitor that can influence choice via counterfactual action-outcome associations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Erasing sensorimotor memories via PKMzeta inhibition.

    OpenAIRE

    Lee Michael von Kraus; Todd Charlton Sacktor; Joseph Thachil Francis

    2010-01-01

    Sensorimotor cortex has a role in procedural learning. Previous studies suggested that this learning is subserved by long-term potentiation (LTP), which is in turn maintained by the persistently active kinase, protein kinase Mzeta (PKMzeta). Whereas the role of PKMzeta in animal models of declarative knowledge is established, its effect on procedural knowledge is not well understood. Here we show that PKMzeta inhibition, via injection of zeta inhibitory peptide (ZIP) into the rat sensorimotor...

  14. Fermented Broth in Tyrosinase- and Melanogenesis Inhibition

    OpenAIRE

    Chin-Feng Chan; Ching-Cheng Huang; Ming-Yuan Lee; Yung-Sheng Lin

    2014-01-01

    Fermented broth has a long history of applications in the food, pharmaceutical and cosmetic industries. Recently, the use of fermented broth in skin care products is in ascendance. This review investigates the efficacy of fermented broth in inhibiting tyrosinase and melanogenesis. Possible active ingredients and hypopigmentation mechanisms of fermented broth are discussed, and potential applications of fermented broth in the cosmetic industry are also addressed.

  15. Fermented Broth in Tyrosinase- and Melanogenesis Inhibition

    Directory of Open Access Journals (Sweden)

    Chin-Feng Chan

    2014-08-01

    Full Text Available Fermented broth has a long history of applications in the food, pharmaceutical and cosmetic industries. Recently, the use of fermented broth in skin care products is in ascendance. This review investigates the efficacy of fermented broth in inhibiting tyrosinase and melanogenesis. Possible active ingredients and hypopigmentation mechanisms of fermented broth are discussed, and potential applications of fermented broth in the cosmetic industry are also addressed.

  16. Tiotropium bromide inhibits human monocyte chemotaxis

    Directory of Open Access Journals (Sweden)

    Kurai M

    2012-08-01

    Full Text Available Tiotropium bromide (Spiriva® is used as a bronchodilator in chronic obstructive pulmonary disease (COPD. However, clinical evidence suggests that tiotropium bromide may improve COPD by mechanisms beyond bronchodilation. We hypothesized that tiotropium bromide may act as an anti-inflammatory agent by inhibiting monocyte chemotaxis, a process that plays an important role in the lung inflammation of COPD. To test this hypothesis monocytes were pretreated with tiotropium bromide prior to exposure to chemotactic agents and monocyte chemotactic activity (MCA was evaluated with a blind chamber technique. Tiotropium bromide inhibited MCA in a dose- and time- dependent manner (respectively, p< 0.01 by directly acting on the monocyte. Acetylcholine (ACh challenge increased MCA (p< 0.01, and tiotropium bromide effectively reduced (p< 0.01 the increase in MCA by ACh. The inhibition of MCA by tiotropium bromide was reversed by a muscarinic type 3 (M3-muscarinic receptor antagonist (p< 0.01, and was not effected by an M2 receptor antagonist. Furthermore, a selective M3 receptor agonist, cevimeline, and Gq protein stimulator, Pasteurella multocida toxin, significantly increased MCA (P < 0.01, and tiotropium bromide pretreatment reduced (p< 0.01 the increase in MCA induced by these agents. These results suggest that tiotropium might regulate monocyte chemotaxis, in part, by interfering with M3-muscarinic receptor coupled Gq protein signal transduction. These results provide new insight that an anti-cholinergic therapeutic may provide anti-inflammatory action in the pulmonary system.

  17. Menaquinone analogs inhibit growth of bacterial pathogens.

    Science.gov (United States)

    Schlievert, Patrick M; Merriman, Joseph A; Salgado-Pabón, Wilmara; Mueller, Elizabeth A; Spaulding, Adam R; Vu, Bao G; Chuang-Smith, Olivia N; Kohler, Petra L; Kirby, John R

    2013-11-01

    Gram-positive bacteria cause serious human illnesses through combinations of cell surface and secreted virulence factors. We initiated studies with four of these organisms to develop novel topical antibacterial agents that interfere with growth and exotoxin production, focusing on menaquinone analogs. Menadione, 1,4-naphthoquinone, and coenzymes Q1 to Q3 but not menaquinone, phylloquinone, or coenzyme Q10 inhibited the growth and to a greater extent exotoxin production of Staphylococcus aureus, Bacillus anthracis, Streptococcus pyogenes, and Streptococcus agalactiae at concentrations of 10 to 200 μg/ml. Coenzyme Q1 reduced the ability of S. aureus to cause toxic shock syndrome in a rabbit model, inhibited the growth of four Gram-negative bacteria, and synergized with another antimicrobial agent, glycerol monolaurate, to inhibit S. aureus growth. The staphylococcal two-component system SrrA/B was shown to be an antibacterial target of coenzyme Q1. We hypothesize that menaquinone analogs both induce toxic reactive oxygen species and affect bacterial plasma membranes and biosynthetic machinery to interfere with two-component systems, respiration, and macromolecular synthesis. These compounds represent a novel class of potential topical therapeutic agents.

  18. Exploiting oleuropein for inhibiting collagen fibril formation.

    Science.gov (United States)

    Bharathy, H; Fathima, N Nishad

    2017-08-01

    Collagen fibrils accumulate in excessive amounts and impair the normal functioning of the organ; therefore it stimulates the interest for identifying the compounds that could prevent the formation of fibrils. Herein, inhibition of self-assembly of collagen using oleuropein has been studied. The changes in the physico-chemical characteristics of collagen on interaction with increasing concentration of oleuropein has been studied using techniques like viscosity, UV-vis, CD and FT-IR. The inhibitory effect of oleuropein on fibril formation of collagen was proved using SEM. Circular dichroism and FT-IR spectra elucidates the alterations in the secondary structure of collagen suggesting non-covalent interactions between oleuropein and collagen. The decreased rate of collagen fibril formation also confirms the inhibition in the self-assembly of collagen. Hence, our study suggests that inhibition of the self-assembly process using oleuropein may unfold new avenues to treat fibrotic diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Alpha-amylase inhibition kinetics by caulerpenyne

    Directory of Open Access Journals (Sweden)

    S. CENGIZ

    2010-03-01

    Full Text Available Many algae have important secretions which are generally used for defensive purposes. These secretions take attentions of a lot of researchers who are wondering if these metabolites can be used for medical researches or not. Among these metabolites, caulerpenyne (CYN which is the main metabolite of Caulerpa species, have had an important place in Caulerpa researches since the results related to its determined properties such as cytotoxic, antiviral, antiproliferative and apoptotic effects have been proven by many scientific reports. In the present study, the inhibitory effect of CYN isolated from C. prolifera on alpha-amylase was investigated. The inhibition experiments were done with CYN by spectrophotometric determination method. In order to evaluate the type of inhibition Lineweaver–Burk plot was produced. The results obtained from enzyme kinetic studies exhibited an un-competitive type of inhibition, which is characterized by the difference of Vmax and KM from those of the free enzyme, of alpha-amylase in the presence of CYN. The present study showed that Caulerpa species can be a potential target for producing diabetic drugs in the light of the results obtained for CYN.

  20. Response inhibition in motor conversion disorder.

    Science.gov (United States)

    Voon, Valerie; Ekanayake, Vindhya; Wiggs, Edythe; Kranick, Sarah; Ameli, Rezvan; Harrison, Neil A; Hallett, Mark

    2013-05-01

    Conversion disorders (CDs) are unexplained neurological symptoms presumed to be related to a psychological issue. Studies focusing on conversion paralysis have suggested potential impairments in motor initiation or execution. Here we studied CD patients with aberrant or excessive motor movements and focused on motor response inhibition. We also assessed cognitive measures in multiple domains. We compared 30 CD patients and 30 age-, sex-, and education-matched healthy volunteers on a motor response inhibition task (go/no go), along with verbal motor response inhibition (color-word interference) and measures of attention, sustained attention, processing speed, language, memory, visuospatial processing, and executive function including planning and verbal fluency. CD patients had greater impairments in commission errors on the go/no go task (P conversion. Patients with nonepileptic seizures, a different form of conversion disorder, are commonly reported to have lower IQ and multiple cognitive deficits. Our results point toward potential differences between conversion disorder subgroups. © 2013 Movement Disorder Society. Copyright © 2013 Movement Disorder Society.

  1. Inhibition of Enveloped Viruses Infectivity by Curcumin

    Science.gov (United States)

    Wen, Hsiao-Wei; Ou, Jun-Lin; Chiou, Shyan-Song; Chen, Jo-Mei; Wong, Min-Liang; Hsu, Wei-Li

    2013-01-01

    Curcumin, a natural compound and ingredient in curry, has antiinflammatory, antioxidant, and anticarcinogenic properties. Previously, we reported that curcumin abrogated influenza virus infectivity by inhibiting hemagglutination (HA) activity. This study demonstrates a novel mechanism by which curcumin inhibits the infectivity of enveloped viruses. In all analyzed enveloped viruses, including the influenza virus, curcumin inhibited plaque formation. In contrast, the nonenveloped enterovirus 71 remained unaffected by curcumin treatment. We evaluated the effects of curcumin on the membrane structure using fluorescent dye (sulforhodamine B; SRB)-containing liposomes that mimic the viral envelope. Curcumin treatment induced the leakage of SRB from these liposomes and the addition of the influenza virus reduced the leakage, indicating that curcumin disrupts the integrity of the membranes of viral envelopes and of liposomes. When testing liposomes of various diameters, we detected higher levels of SRB leakage from the smaller-sized liposomes than from the larger liposomes. Interestingly, the curcumin concentration required to reduce plaque formation was lower for the influenza virus (approximately 100 nm in diameter) than for the pseudorabies virus (approximately 180 nm) and the vaccinia virus (roughly 335 × 200 × 200 nm). These data provide insights on the molecular antiviral mechanisms of curcumin and its potential use as an antiviral agent for enveloped viruses. PMID:23658730

  2. Somatomedins inhibit protein degradation in muscle cell

    International Nuclear Information System (INIS)

    Roeder, R.A.; Blann, D.L.; Bauer, C.A.; Hossner, K.L.

    1986-01-01

    Protein degradation has been measured in cultures of L6 myotubes as the rate of release of trichloroacetic acid-soluble radioactivity after prelabeling cell protein with [ 3 H] leucine. Insulin-like growth factor-I (IGF-1), ovine somatomedin (oSM) and insulin (I), at concentrations from 10 -11 M to 10 -7 M (5 x 10 -7 M-oSM) were added at the beginning of a 4-hour degradation period to determine the effects of these hormones on inducible proteolysis occurring in serum-free media. In addition the effects of fetal bovine serum, at concentrations from 1% to 30%, on protein degradation were determined in parallel experiments to relate serum inhibition of proteolysis to somatomedin actions. Results from this study indicate the apparent half maximal inhibition of proteolysis (18%, 15%, 11%) occurred at .4nM-IGF-1, .6nM-oSM and 4nM-I, respectively. Thus protein degradation was approximately 10 times more sensitive to somatomedins than insulin. The half maximal inhibition of proteolysis (15%) observed with serum occurred at 7.7%. The magnitude of the response between IFG-I and serum (37% vs. 31%) was similar. These results are consistent with the hypothesis that somatomedins are important factors in regulating growth and development of muscle

  3. Kinetics, mechanism, and inhibition of monoamine oxidase.

    Science.gov (United States)

    Ramsay, Rona R; Albreht, Alen

    2018-03-07

    Monoamine oxidases (MAOs) catalyse the oxidation of neurotransmitter amines and a wide variety of primary, secondary and tertiary amine xenobiotics, including therapeutic drugs. While inhibition of MAO activity in the periphery removes protection from biogenic amines and so is undesirable, inhibition in the brain gives vital antidepressant and behavioural advantages that make MAO a major pharmaceutical target for inhibitor design. In neurodegenerative diseases, MAO inhibitors can help to maintain neurotransmitter levels, making it a common feature in novel multi-target combinations designed to combat Alzheimer's disease, albeit not yet proven clinically. Vital information for inhibitor design comes from an understanding of the structure, mechanism, and kinetics of the catalyst. This review will summarize the kinetic behaviour of MAO A and B and the kinetic evaluation of reversible inhibitors that transiently decrease catalysis. Kinetic parameters and crystal structures have enabled computational approaches to ligand discovery and validation of hits by docking. Kinetics and a wide variety of substrates and inhibitors along with theoretical modelling have also contributed to proposed schemes for the still debated chemical mechanism of amine oxidation. However, most of the marketed MAO drugs are long-lasting irreversible inactivators. The mechanism of irreversible inhibition by hydrazine, cyclopropylamine, and propargylamine drugs will be discussed. The article finishes with some examples of the propargylamine moiety in multi-target ligand design to combat neurodegeneration.

  4. Inhibition of topoisomerase II by liriodenine.

    Science.gov (United States)

    Woo, S H; Reynolds, M C; Sun, N J; Cassady, J M; Snapka, R M

    1997-08-15

    The cytotoxic oxoaporphine alkaloid liriodenine, isolated from Cananga odorata, was found to be a potent inhibitor of topoisomerase II (EC 5.99.1.3) both in vivo and in vitro. Liriodenine treatment of SV40 (simian virus 40)-infected CV-1 cells caused highly catenated SV40 daughter chromosomes, a signature of topoisomerase II inhibition. Strong catalytic inhibition of topoisomerase II by liriodenine was confirmed by in vitro assays with purified human topoisomerase II and kinetoplast DNA. Liriodenine also caused low-level protein-DNA cross-links to pulse-labeled SV40 chromosomes in vivo, suggesting that it may be a weak topoisomerase II poison. This was supported by the finding that liriodenine caused topoisomerase II-DNA cross-links in an in vitro assay for topoisomerase II poisons. Verapamil did not increase either liriodenine-induced protein-DNA cross-links or catalytic inhibition of topoisomerase II in SV40-infected cells. This indicates that liriodenine is not a substrate for the verapamil-sensitive drug efflux pump in CV-1 cells.

  5. Phytic Acid Inhibits Lipid Peroxidation In Vitro

    Directory of Open Access Journals (Sweden)

    Alicja Zajdel

    2013-01-01

    Full Text Available Phytic acid (PA has been recognized as a potent antioxidant and inhibitor of iron-catalyzed hydroxyl radical formation under in vitro and in vivo conditions. Therefore, the aim of the present study was to investigate, with the use of HPLC/MS/MS, whether PA is capable of inhibiting linoleic acid autoxidation and Fe(II/ascorbate-induced peroxidation, as well as Fe(II/ascorbate-induced lipid peroxidation in human colonic epithelial cells. PA at 100 μM and 500 μM effectively inhibited the decay of linoleic acid, both in the absence and presence of Fe(II/ascorbate. The observed inhibitory effect of PA on Fe(II/ascorbate-induced lipid peroxidation was lower (10–20% compared to that of autoxidation. PA did not change linoleic acid hydroperoxides concentration levels after 24 hours of Fe(II/ascorbate-induced peroxidation. In the absence of Fe(II/ascorbate, PA at 100 μM and 500 μM significantly suppressed decomposition of linoleic acid hydroperoxides. Moreover, PA at the tested nontoxic concentrations (100 μM and 500 μM significantly decreased 4-hydroxyalkenal levels in Caco-2 cells which structurally and functionally resemble the small intestinal epithelium. It is concluded that PA inhibits linoleic acid oxidation and reduces the formation of 4-hydroxyalkenals. Acting as an antioxidant it may help to prevent intestinal diseases induced by oxygen radicals and lipid peroxidation products.

  6. Inhibition of SIRT2 suppresses hepatic fibrosis.

    Science.gov (United States)

    Arteaga, Maribel; Shang, Na; Ding, Xianzhong; Yong, Sherri; Cotler, Scott J; Denning, Mitchell F; Shimamura, Takashi; Breslin, Peter; Lüscher, Bernhard; Qiu, Wei

    2016-06-01

    Liver fibrosis can progress to cirrhosis and result in serious complications of liver disease. The pathogenesis of liver fibrosis involves the activation of hepatic stellate cells (HSCs), the underlying mechanisms of which are not fully known. Emerging evidence suggests that the classic histone deacetylases play a role in liver fibrosis, but the role of another subfamily of histone deacetylases, the sirtuins, in the development of hepatic fibrosis remains unknown. In this study, we found that blocking the activity of sirtuin 2 (SIRT2) by using inhibitors or shRNAs significantly suppressed fibrogenic gene expression in HSCs. We further demonstrated that inhibition of SIRT2 results in the degradation of c-MYC, which is important for HSC activation. In addition, we discovered that inhibition of SIRT2 suppresses the phosphorylation of ERK, which is critical for the stabilization of c-MYC. Moreover, we found that Sirt2 deficiency attenuates the hepatic fibrosis induced by carbon tetrachloride (CCl4) and thioacetamide (TAA). Furthermore, we showed that SIRT2, p-ERK, and c-MYC proteins are all overexpressed in human hepatic fibrotic tissues. These data suggest a critical role for the SIRT2/ERK/c-MYC axis in promoting hepatic fibrogenesis. Inhibition of the SIRT2/ERK/c-MYC axis represents a novel strategy to prevent and to potentially treat liver fibrosis and cirrhosis. Copyright © 2016 the American Physiological Society.

  7. Pharmacological inhibition of feline immunodeficiency virus (FIV).

    Science.gov (United States)

    Mohammadi, Hakimeh; Bienzle, Dorothee

    2012-05-01

    Feline immunodeficiency virus (FIV) is a member of the retroviridae family of viruses and causes an acquired immunodeficiency syndrome (AIDS) in domestic and non-domestic cats worldwide. Genome organization of FIV and clinical characteristics of the disease caused by the virus are similar to those of human immunodeficiency virus (HIV). Both viruses infect T lymphocytes, monocytes and macrophages, and their replication cycle in infected cells is analogous. Due to marked similarity in genomic organization, virus structure, virus replication and disease pathogenesis of FIV and HIV, infection of cats with FIV is a useful tool to study and develop novel drugs and vaccines for HIV. Anti-retroviral drugs studied extensively in HIV infection have targeted different steps of the virus replication cycle: (1) inhibition of virus entry into susceptible cells at the level of attachment to host cell surface receptors and co-receptors; (2) inhibition of fusion of the virus membrane with the cell membrane; (3) blockade of reverse transcription of viral genomic RNA; (4) interruption of nuclear translocation and viral DNA integration into host genomes; (5) prevention of viral transcript processing and nuclear export; and (6) inhibition of virion assembly and maturation. Despite much success of anti-retroviral therapy slowing disease progression in people, similar therapy has not been thoroughly investigated in cats. In this article we review current pharmacological approaches and novel targets for anti-lentiviral therapy, and critically assess potentially suitable applications against FIV infection in cats.

  8. [Inhibition of soybean urease by polycarbonyl compounds].

    Science.gov (United States)

    Tarun, E I; Rubinov, D B; Metelitsa, D I

    2005-01-01

    Competitive inhibition of soybean urease was studied at 36 degrees C in aqueous solution (pH 4.95) in the presence of polycarbonyl compounds (PCCs): oxalyldihydrazide (ODH), its polydisulfide (poly(DSODH)), three cyclic beta-triketones (CTKs), and seven cyclic PCC species of differing structure. The inhibition constants of ureolysis (Ki) varied in the range 8.5-3800 microM depending on the structure of organic chelators for the nickel atom in urease. It was shown that pH variation within the range from 3.85 to 7.40 exerted a strong effect on the values of Ki] of three CTKs and hydroxyurea, which was used as a reference: pH dependences of lgK(i) were linear in all cases and displayed a break at pH 6.0-6.5. The most effective inhibitor of ureolysis was poly(DSODH), which contained approximately 28 carbonyl groups in the polymer molecule. The role of such factors as the number of carbonyl groups per PCC molecule, mutual arrangement, and reaction medium pH in the efficiency of the process of urease inhibition is discussed.

  9. Wnt signaling inhibits CTL memory programming.

    Science.gov (United States)

    Xiao, Zhengguo; Sun, Zhifeng; Smyth, Kendra; Li, Lei

    2013-12-01

    Induction of functional CTLs is one of the major goals for vaccine development and cancer therapy. Inflammatory cytokines are critical for memory CTL generation. Wnt signaling is important for CTL priming and memory formation, but its role in cytokine-driven memory CTL programming is unclear. We found that wnt signaling inhibited IL-12-driven CTL activation and memory programming. This impaired memory CTL programming was attributed to up-regulation of eomes and down-regulation of T-bet. Wnt signaling suppressed the mTOR pathway during CTL activation, which was different to its effects on other cell types. Interestingly, the impaired memory CTL programming by wnt was partially rescued by mTOR inhibitor rapamycin. In conclusion, we found that crosstalk between wnt and the IL-12 signaling inhibits T-bet and mTOR pathways and impairs memory programming which can be recovered in part by rapamycin. In addition, direct inhibition of wnt signaling during CTL activation does not affect CTL memory programming. Therefore, wnt signaling may serve as a new tool for CTL manipulation in autoimmune diseases and immune therapy for certain cancers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Spatholobus suberectus inhibits osteoclastogenesis and stimulates chondrogenesis.

    Science.gov (United States)

    Im, Nam-Kyung; Lee, Sung-Gyu; Lee, Dong-Sung; Park, Pil-Hoon; Lee, In-Seon; Jeong, Gil-Saeng

    2014-01-01

    This study was carried out to investigate the effect of Spatholobus suberectus Dunn (SS) on the protection of chondral defect and inhibition of osteoclastogenesis. To examine these effects, we measured the matrix metalloproteinase (MMP) levels in SW1353 chondrosarcoma cells and performed tartrate-resistant acid phosphatase (TRAP) staining in bone marrow macrophage (BMM)-derived osteoclasts. To investigate the anti-osteoarthritis (OA) effects, we assessed TNF-α-induced MMP-1, -3, -9 and tissue inhibitors of matrix metalloproteinase (TIMP) expression levels in SW1353 cells. We observed that SS extract significantly inhibited MMP and TIMP expression in SW1353 cells. Also, SS extract inhibited the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation. These results suggest that SS extract may have a potential in the treatment of bone loss and chondral defect by suppressing osteoclast differentiation and decreasing the expression of OA factors. Therefore, clarification of the mechanism of the action of SS extract and its active components is needed.

  11. In Vivo Pharmacodynamic Imaging of Proteasome Inhibition

    Directory of Open Access Journals (Sweden)

    Erin A. Kimbrel

    2009-05-01

    Full Text Available Inhibiting the proteolytic activity of the 26S proteasome has been shown to have selective apoptotic effects on cancer cells and to be clinically efficacious in certain malignancies. There is an unmet medical need for additional proteasome inhibitors, and their development will be facilitated by surrogate markers of proteasome function. Toward this end, ectopic fusion of the destruction domain from ornithine decarboxylase (ODC to reporter proteins is often used for assessing proteasome function. For luciferase-based reporters, we hypothesized that the oxygen-dependent destruction domain (ODD from hypoxia-inducible factor 1α (HIF-1α may provide improved sensitivity over luciferase-ODC, owing to its extremely rapid turnover by the proteasome (HIF-1α has a half-life of less than 5 minutes. In the current study, we show that ODD-luciferase affords a greater dynamic range and faster kinetics than luciferase-ODC in sensing proteasome inhibition in vitro. Importantly, ODD-luciferase also serves as an effective in vivo marker of proteasome function in xenograft tumor models, with inhibition being detected by noninvasive imaging within 3 hours of bortezomib administration. These data establish ODD-luciferase as a surrogate marker of proteasome function that can be used both in vitro and in vivo for the development of novel proteasome inhibitors.

  12. Inhibition of enveloped viruses infectivity by curcumin.

    Directory of Open Access Journals (Sweden)

    Tzu-Yen Chen

    Full Text Available Curcumin, a natural compound and ingredient in curry, has antiinflammatory, antioxidant, and anticarcinogenic properties. Previously, we reported that curcumin abrogated influenza virus infectivity by inhibiting hemagglutination (HA activity. This study demonstrates a novel mechanism by which curcumin inhibits the infectivity of enveloped viruses. In all analyzed enveloped viruses, including the influenza virus, curcumin inhibited plaque formation. In contrast, the nonenveloped enterovirus 71 remained unaffected by curcumin treatment. We evaluated the effects of curcumin on the membrane structure using fluorescent dye (sulforhodamine B; SRB-containing liposomes that mimic the viral envelope. Curcumin treatment induced the leakage of SRB from these liposomes and the addition of the influenza virus reduced the leakage, indicating that curcumin disrupts the integrity of the membranes of viral envelopes and of liposomes. When testing liposomes of various diameters, we detected higher levels of SRB leakage from the smaller-sized liposomes than from the larger liposomes. Interestingly, the curcumin concentration required to reduce plaque formation was lower for the influenza virus (approximately 100 nm in diameter than for the pseudorabies virus (approximately 180 nm and the vaccinia virus (roughly 335 × 200 × 200 nm. These data provide insights on the molecular antiviral mechanisms of curcumin and its potential use as an antiviral agent for enveloped viruses.

  13. Bioassays for the determination of nitrification inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Grunditz, Camilla

    1999-07-01

    Requirements for nitrogen reduction in wastewater treatment plants were introduced in Sweden in the early 1990's. This was a governmental move to reduce the nitrogen discharges to the Baltic and Kattegat in order to prevent eutrophication. The nitrification process in wastewater treatment plants is performed by nitrifying bacteria. These are susceptible to inhibition and it is of great importance that the influent water does not contain toxic compounds. Therefore, there is a need for assays for the determination of nitrification inhibition. This thesis describes the development and applications of such bioassays. Pure cultures of Nitrosomonas sp. and Nitrobacter sp. were isolated from activated sludge of a wastewater treatment plant. These cultures were used as test organisms in the development of bioassays for nitrification inhibition measurements. The assays are based on two different principles; cell suspensions of the bacteria, performed in test tubes, and mediated amperometric biosensors with the bacteria immobilised. Ammonia oxidation and nitrite oxidation are studied separately without interference from other organisms, which makes it easier to interpret the results. The cell suspension assays were applied to samples of industrial and municipal wastewater. The Nitrosomonas and Nitrobacter assays showed to have different inhibition patterns. A large percentage of the Swedish municipal wastewater treatment plants were found to receive inhibitory influent water, but the inhibition level was generally low. Compared to an assay based on activated sludge, the screening method, the pure culture assays found more samples of influent water strongly inhibitory or stimulating. The highest correlation was found between the screening method and the Nitrosomonas assay. The Nitrobacter assay was found to be the most sensitive method. Assessment of toxicity of a number of chemical substances was studied using the biosensors, together with the cell suspension assays

  14. Thiomers: Inhibition of cytochrome P450 activity.

    Science.gov (United States)

    Iqbal, Javed; Sakloetsakun, Duangkamon; Bernkop-Schnürch, Andreas

    2011-08-01

    The aim of the present study was to investigate the potential of different thiolated polymers (thiomers) on the catalytic activity of CYP450s on one hand and to explore new inhibitors for CYP activity on the other hand. Several thiolated polymers including poly(acrylic acid)-cysteine (PAA-cysteine), chitosan-thioglycolic acid (chitosan-TGA), and thiolated PEG-g-PEI copolymer along with brij 35, myrj 52 and the well-established CYPP450 inhibitor verapamil were screened for their CYP3A4 and CYP2A6 inhibitory activity, and their IC(50) values were determined. Both enzyme inhibition assays were performed in 96-well microtiter plates. 7-Benzyloxy-4-(trifluoromethyl)-coumarin (BFC) and 7-hydroxycoumarin (7-HC) were used as fluorescent substrates in order to determine CYP3A4 and CYP2A6 catalytic activity, respectively. All investigated compounds inhibited CYP3A4 as well as CYP2A6 activity. All tested (thiolated) polymers were found to be more potent inhibitors of CYP3A4 than of CYP2A6 catalytic activity. Apart from verapamil that is a known CYP3A4 inhibitor, brij 35 and myrj 52 were explored as potent inhibitors of CYP3A4 and CYP2A6 catalytic activity. Among the tested polymers, the rank order for CYP3A4 inhibition was PAA-cysteine (100 kDa)>brij 35>thiolated PEG-g-PEI copolymer (16 kDa)>myrj 52>PAA (100 kDa)>PAA-cysteine (450 kDa)>verapamil>PAA (450 kDa)>chitosan-TGA (150 kDa)>chitosan (150 kDa). On the other hand, the rank order of CYP2A6 inhibition was brij 35>PAA-cysteine (100kDa)>chitosan-TGA (150 kDa)>PAA (100 kDa)>thiolated PEG-g-PEI copolymer (16 kDa)>PAA-cysteine (450 kDa)>chitosan (150 kDa)>verapamil>PAA (450 kDa)>myrj 52. Thus, this study suggests that (thiolated) polymers display a promising potential to inhibit cytochrome P450s activity and might turn out to be potentially valuable tools for improving the oral bioavailability of actively secreted compounds by avoiding intestinal metabolism. Copyright © 2011. Published by Elsevier B.V.

  15. A specific bioassay for the inhibition of flowering.

    Science.gov (United States)

    Blake, J

    1972-06-01

    A bioassay for the inhibition of flowering involving the in vitro culture of excised, partially-induced, apices of Viscaria candida is described. This bioassay has been used to detect flowering inhibition in extracts from Kalanchoe blossfeldiana.

  16. The development of children's inhibition: Does parenting matter?

    OpenAIRE

    Roskam, I.; Stievenart, Marie; Meunier, J.-C.; Noël, M.-P.

    2014-01-01

    Whereas a large body of research has investigated the maturation of inhibition in relation to the prefrontal cortex, far less research has been devoted to environmental factors that could contribute to inhibition improvement. The aim of the current study was to test whether and to what extent parenting matters for inhibition development from 2 to 8. years of age. Data were collected from 421 families, with 348 mother-child dyads and 342 father-child dyads participating. Children's inhibition ...

  17. Use of bacillus subtilis strains to inhibit postharvest pathogenic fungi

    International Nuclear Information System (INIS)

    Arras, G.; Gambella, F.; Demontis, S.; Petretto, A.

    1995-01-01

    An isolate (87) of the bacillus subtilis strains isolated from cold stored citrus fruit 13 proved to inhibit the growth in vitro of the penicillium italicum used in the experiment (from 50.6% to 92.2%) and to inhibit botrytis cinerea (from 65.3% to 95.9%). A further test, superimposing on plates containing PDA strains Nos. 13, 173, and 160, totally inhibited the fungi. Tested in vivo on artificially bruised oranges, they significantly inhibited two fungi

  18. Lysis of lysis-inhibited bacteriophage T4-infected cells.

    OpenAIRE

    Abedon, S T

    1992-01-01

    T4 bacteriophage (phage)-infected cells show a marked increase in latent-period length, called lysis inhibition, upon adsorption of additional T4 phages (secondary adsorption). Lysis inhibition is a complex phenotype requiring the activity of at least six T4 genes. Two basic mysteries surround our understanding of the expression of lysis inhibition: (i) the mechanism of initiation (i.e., how secondary adsorption leads to the expression of lysis inhibition) and (ii) the mechanism of lysis (i.e...

  19. The role of behavioural inhibition in preschoolers' emotion understanding

    OpenAIRE

    Bernstein, Dagmar

    2009-01-01

    Behavioural inhibition to the unfamiliar is a temperamental style of reacting to novel situations, peers or adults with fear, wariness and avoidance. Childhood behavioural inhibition is a well-established risk factor for anxiety disorders, particularly social phobia. However, there is presently a gap in the literature with regard to possible links between behavioural inhibition and children’s social development, including their social cognition. There is evidence that behavioural inhibition p...

  20. A fusion-inhibiting peptide against Rift Valley fever virus inhibits multiple, diverse viruses.

    Directory of Open Access Journals (Sweden)

    Jeffrey W Koehler

    Full Text Available For enveloped viruses, fusion of the viral envelope with a cellular membrane is critical for a productive infection to occur. This fusion process is mediated by at least three classes of fusion proteins (Class I, II, and III based on the protein sequence and structure. For Rift Valley fever virus (RVFV, the glycoprotein Gc (Class II fusion protein mediates this fusion event following entry into the endocytic pathway, allowing the viral genome access to the cell cytoplasm. Here, we show that peptides analogous to the RVFV Gc stem region inhibited RVFV infectivity in cell culture by inhibiting the fusion process. Further, we show that infectivity can be inhibited for diverse, unrelated RNA viruses that have Class I (Ebola virus, Class II (Andes virus, or Class III (vesicular stomatitis virus fusion proteins using this single peptide. Our findings are consistent with an inhibition mechanism similar to that proposed for stem peptide fusion inhibitors of dengue virus in which the RVFV inhibitory peptide first binds to both the virion and cell membranes, allowing it to traffic with the virus into the endocytic pathway. Upon acidification and rearrangement of Gc, the peptide is then able to specifically bind to Gc and prevent fusion of the viral and endocytic membranes, thus inhibiting viral infection. These results could provide novel insights into conserved features among the three classes of viral fusion proteins and offer direction for the future development of broadly active fusion inhibitors.

  1. Effect of Adenine Concentration on the Corrosion Inhibition of Aisi ...

    African Journals Online (AJOL)

    This gave a surface coverage of 0.8956 and corrosion penetration rate of 0.022132mm/yr. Hence, the best adenine concentration for the corrosion inhibition of alloys 304L in 1.0M sulphuric acid solution to obtain optimum inhibition efficiency is 0.011M. Keywords: Corrosion, AISI 304L Steel, Inhibition efficiency, Degree of ...

  2. Inhibition of Inducible Nitric Oxide Synthase, Cycleooxygenase-2 ...

    African Journals Online (AJOL)

    Inhibition of Inducible Nitric Oxide Synthase, Cycleooxygenase-2 and Lipid Peroxidation by Methanol Extract of Pericarpium Zanthoxyli. ... Production of iNOS induced by LPS was significantly (p < 0.05) inhibited by the extract, suggesting that the extract inhibits nitric oxide (NO) production by suppressing iNOS expression.

  3. Contour detection based on nonclassical receptive field inhibition

    NARCIS (Netherlands)

    Grigorescu, Cosmin; Petkov, Nicolai; Westenberg, Michel A.

    We propose a biologically motivated computational step, called nonclassical receptive field (non-CRF) inhibition, more generally surround inhibition or suppression, to improve contour detection in machine vision. Non-CRF inhibition is exhibited by 80% of the orientation-selective neurons in the

  4. Inhibition and Adsorption impact of Leave Extracts of Cnidoscolus ...

    African Journals Online (AJOL)

    Corrosion inhibition in the presence of alokaloid and non alkaloid extracts of Cnidoscolus aconitifolius in 1M HCl was studied using the weight loss and hydrogen evolution techniques at 303, 313 and 333 K. The results obtained revealed that the inhibition efficiency decreased with increase in temperature. Inhibition ...

  5. Inhibition of acetylcholinesterase activity by essential oil from Citrus paradisi.

    Science.gov (United States)

    Miyazawa, M; Tougo, H; Ishihara, M

    2001-01-01

    Inhibition of acetylcholinesterase (AChE) activity by essential oils of Citrus paradisi (grapefruit pink in USA) was studied. Inhibition of AChE was measured by the colorimetric method. Nootkatone and auraptene were isolated from C. paradisi oil and showed 17-24% inhibition of AChE activity at the concentration of 1.62 microg/mL.

  6. Interferon-γ Inhibits Ebola Virus Infection.

    Directory of Open Access Journals (Sweden)

    Bethany A Rhein

    Full Text Available Ebola virus outbreaks, such as the 2014 Makona epidemic in West Africa, are episodic and deadly. Filovirus antivirals are currently not clinically available. Our findings suggest interferon gamma, an FDA-approved drug, may serve as a novel and effective prophylactic or treatment option. Using mouse-adapted Ebola virus, we found that murine interferon gamma administered 24 hours before or after infection robustly protects lethally-challenged mice and reduces morbidity and serum viral titers. Furthermore, we demonstrated that interferon gamma profoundly inhibits Ebola virus infection of macrophages, an early cellular target of infection. As early as six hours following in vitro infection, Ebola virus RNA levels in interferon gamma-treated macrophages were lower than in infected, untreated cells. Addition of the protein synthesis inhibitor, cycloheximide, to interferon gamma-treated macrophages did not further reduce viral RNA levels, suggesting that interferon gamma blocks life cycle events that require protein synthesis such as virus replication. Microarray studies with interferon gamma-treated human macrophages identified more than 160 interferon-stimulated genes. Ectopic expression of a select group of these genes inhibited Ebola virus infection. These studies provide new potential avenues for antiviral targeting as these genes that have not previously appreciated to inhibit negative strand RNA viruses and specifically Ebola virus infection. As treatment of interferon gamma robustly protects mice from lethal Ebola virus infection, we propose that interferon gamma should be further evaluated for its efficacy as a prophylactic and/or therapeutic strategy against filoviruses. Use of this FDA-approved drug could rapidly be deployed during future outbreaks.

  7. Cannabidiol inhibits angiogenesis by multiple mechanisms

    Science.gov (United States)

    Solinas, M; Massi, P; Cantelmo, AR; Cattaneo, MG; Cammarota, R; Bartolini, D; Cinquina, V; Valenti, M; Vicentini, LM; Noonan, DM; Albini, A; Parolaro, D

    2012-01-01

    BACKGROUND AND PURPOSE Several studies have demonstrated anti-proliferative and pro-apoptotic actions of cannabinoids on various tumours, together with their anti-angiogenic properties. The non-psychoactive cannabinoid cannabidiol (CBD) effectively inhibits the growth of different types of tumours in vitro and in vivo and down-regulates some pro-angiogenic signals produced by glioma cells. As its anti-angiogenic properties have not been thoroughly investigated to date, and given its very favourable pharmacological and toxicological profile, here, we evaluated the ability of CBD to modulate tumour angiogenesis. EXPERIMENTAL APPROACH Firstly, we evaluated the effect of CBD on human umbilical vein endothelial cell (HUVEC) proliferation and viability – through [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and FACS analysis – and in vitro motility – both in a classical Boyden chamber test and in a wound-healing assay. We next investigated CBD effects on different angiogenesis-related proteins released by HUVECs, using an angiogenesis array kit and an ELISA directed at MMP2. Then we evaluated its effects on in vitro angiogenesis in treated HUVECs invading a Matrigel layer and in HUVEC spheroids embedded into collagen gels, and further characterized its effects in vivo using a Matrigel sponge model of angiogenesis in C57/BL6 mice. KEY RESULTS CBD induced HUVEC cytostasis without inducing apoptosis, inhibited HUVEC migration, invasion and sprouting in vitro, and angiogenesis in vivo in Matrigel sponges. These effects were associated with the down-modulation of several angiogenesis-related molecules. CONCLUSIONS AND IMPLICATIONS This study reveals that CBD inhibits angiogenesis by multiple mechanisms. Its dual effect on both tumour and endothelial cells supports the hypothesis that CBD has potential as an effective agent in cancer therapy. PMID:22624859

  8. Vitamin K3 (menadione) redox cycling inhibits cytochrome P450-mediated metabolism and inhibits parathion intoxication

    International Nuclear Information System (INIS)

    Jan, Yi-Hua; Richardson, Jason R.; Baker, Angela A.; Mishin, Vladimir; Heck, Diane E.; Laskin, Debra L.; Laskin, Jeffrey D.

    2015-01-01

    Parathion, a widely used organophosphate insecticide, is considered a high priority chemical threat. Parathion toxicity is dependent on its metabolism by the cytochrome P450 system to paraoxon (diethyl 4-nitrophenyl phosphate), a cytotoxic metabolite. As an effective inhibitor of cholinesterases, paraoxon causes the accumulation of acetylcholine in synapses and overstimulation of nicotinic and muscarinic cholinergic receptors, leading to characteristic signs of organophosphate poisoning. Inhibition of parathion metabolism to paraoxon represents a potential approach to counter parathion toxicity. Herein, we demonstrate that menadione (methyl-1,4-naphthoquinone, vitamin K3) is a potent inhibitor of cytochrome P450-mediated metabolism of parathion. Menadione is active in redox cycling, a reaction mediated by NADPH-cytochrome P450 reductase that preferentially uses electrons from NADPH at the expense of their supply to the P450s. Using human recombinant CYP 1A2, 2B6, 3A4 and human liver microsomes, menadione was found to inhibit the formation of paraoxon from parathion. Administration of menadione bisulfite (40 mg/kg, ip) to rats also reduced parathion-induced inhibition of brain cholinesterase activity, as well as parathion-induced tremors and the progression of other signs and symptoms of parathion poisoning. These data suggest that redox cycling compounds, such as menadione, have the potential to effectively mitigate the toxicity of organophosphorus pesticides including parathion which require cytochrome P450-mediated activation. - Highlights: • Menadione redox cycles with cytochrome P450 reductase and generates reactive oxygen species. • Redox cycling inhibits cytochrome P450-mediated parathion metabolism. • Short term administration of menadione inhibits parathion toxicity by inhibiting paraoxon formation.

  9. Vaginal Lactobacillus isolates inhibit uropathogenic Escherichia coli.

    OpenAIRE

    Atassi , Fabrice; Brassart , Dominique; Grob , Philipp; Graf , Federico; Servin , Alain ,

    2006-01-01

    The purpose of this study was to investigate the antibacterial activities of Lactobacillus jensenii KS119.1 and KS121.1, and Lactobacillus gasserii KS120.1 and KS124.3 strains isolated from the vaginal microflora of healthy women, against uropathogenic, diffusely adhering Afa/Dr Escherichia coli (Afa/Dr DAEC) strains IH11128 and 7372 involved in recurrent cystitis. We observed that some of the Lactobacillus isolates inhibited the growth and decreased the viability of E. coli IH11128 and 7372....

  10. Na+/K+-ATPase: Activity and inhibition

    Science.gov (United States)

    Čolović, M.; Krstić, D.; Krinulović, K.; Momić, T.; Savić, J.; Vujačić, A.; Vasić, V.

    2009-09-01

    The aim of the study was to give an overview of the mechanism of inhibition of Na+/K+-ATPase activity induced by some specific and non specific inhibitors. For this purpose, the effects of some ouabain like compounds (digoxin, gitoxin), noble metals complexes ([PtCl2DMSO2], [AuCl4]-, [PdCl4]2-, [PdCl(dien)]+, [PdCl(Me4dien)]+), transition metal ions (Cu2+, Zn2+, Fe2+, Co2+), and heavy metal ions (Hg2+, Pb2+, Cd2+) on the activity of Na+/K+-ATPase from rat synaptic plasma membranes (SPM), porcine cerebral cortex and human erythrocytes were discussed.

  11. Australine, a pyrrolizidine alkaloid that inhibits amyloglucosidase and glycoprotein processing

    International Nuclear Information System (INIS)

    Tropea, J.E.; Molyneux, R.J.; Kaushal, G.P.; Pan, Y.T.; Mitchell, M.; Elbein, A.D.

    1989-01-01

    Australine is a polyhydroxylated pyrrolizidine alkaloid that was isolated from the seeds of the Australian tree Castanospermum australe and characterized by NMR and X-ray diffraction analysis. Since swainsonine and catanospermine are polyhydroxylated indolizidine alkaloids that inhibit specific glycosidases, the authors tested australine against a variety of exoglycosidases to determine whether it would inhibit any of these enzymes. This alkaloid proved to be a good inhibitor of the α-glucosidase amyloglucosidase (50% inhibition at 5.8 μM), but it did not inhibit β-glucosidase, α- or β-mannosidase, or α- or β-galactosidase. The inhibition of amyloglucosidase was of a competitive nature. Australine also inhibited the glycoprotein processing enzyme glucosidase I, but had only slight activity toward glucosidase II. When incubated with cultured cells, this alkaloid inhibited glycoprotein processing at the glucosidase I step and caused the accumulation of glycoproteins with Glc 3 Man 7-9 (GlcNAc) 2 -oligosaccharides

  12. Saccadic inhibition in a guided saccade task

    Directory of Open Access Journals (Sweden)

    Isabel Dombrowe

    2018-03-01

    Full Text Available The eye movement system reacts very systematically to visual transients that are presented during the planning phase of a saccade. About 50 to 70 ms after the onset of a transient, the number of saccades that are started decreases, a phenomenon that has been termed saccadic inhibition. Saccades started just before this time window are hypometric compared to regular saccades, presumably because the presentation of the transient stops them in mid-flight. Recent research investigating the properties of repeated saccades to fixed locations found that these early saccades were additionally faster than expected from the main sequence relation, suggesting that a saccadic dead time during which saccades can no longer be modified does not exist. The present study investigated the properties of saccades to random locations in a guided saccade task. As expected, early saccades starting just before the saccadic inhibition dip in frequency were hypometric. Their velocity profiles implied that these saccades were actively stopped after reaching peak velocity. However, the peak velocities of these saccades did not generally deviate from the main sequence relation. The question whether an active stop of early saccades is incompatible with the idea of a saccadic dead time is open to debate.

  13. Kaempferol inhibits thrombosis and platelet activation.

    Science.gov (United States)

    Choi, Jun-Hui; Park, Se-Eun; Kim, Sung-Jun; Kim, Seung

    2015-08-01

    The objectives of the present study were to investigate whether kaempferol affects pro-coagulant proteinase activity, fibrin clot formation, blood clot and thrombin (or collagen/epinephrine)-stimulated platelet activation, thrombosis, and coagulation in ICR (Imprinting Control Region) mice and SD (Sprague-Dawley) rats. Kaempferol significantly inhibited the enzymatic activities of thrombin and FXa by 68 ± 1.6% and 52 ± 2.4%, respectively. Kaempferol also inhibited fibrin polymer formation in turbidity. Microscopic analysis was performed using a fluorescent conjugate. Kaempferol completely attenuated phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, p38, c-Jun N-terminal kinase (JNK) 1/2, and phosphoinositide 3-kinase (PI3K)/PKB (AKT) in thrombin-stimulated platelets and delayed aggregation time (clotting) by 34.6% in an assay of collagen/epinephrine-stimulated platelet activation. Moreover, kaempferol protected against thrombosis development in 3 animal models, including collagen/epinephrine- and thrombin-induced acute thromboembolism models and an FeCl3-induced carotid arterial thrombus model. The ex vivo anticoagulant effect of kaempferol was further confirmed in ICR mice. This study demonstrated that kaempferol may be clinically useful due to its ability to reduce or prevent thrombotic challenge. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  14. Periostin Limits Tumor Response to VEGFA Inhibition

    Directory of Open Access Journals (Sweden)

    Ioanna Keklikoglou

    2018-03-01

    Full Text Available Resistance to antiangiogenic drugs limits their applicability in cancer therapy. Here, we show that revascularization and progression of pancreatic neuroendocrine tumors (PNETs under extended vascular-endothelial growth factor A (VEGFA blockade are dependent on periostin (POSTN, a matricellular protein expressed by stromal cells. Genetic deletion of Postn in RIP1-Tag2 mice blunted tumor rebounds of M2-like macrophages and αSMA+ stromal cells in response to prolonged VEGFA inhibition and suppressed PNET revascularization and progression on therapy. POSTN deficiency also impeded the upregulation of basic fibroblast growth factor (FGF2, an adaptive mechanism previously implicated in PNET evasion from antiangiogenic therapy. Higher POSTN expression correlated with markers of M2-like macrophages in human PNETs, and depleting macrophages with a colony-stimulating factor 1 receptor (CSF1R antibody inhibited PNET revascularization and progression under VEGFA blockade despite continued POSTN production. These findings suggest a role for POSTN in orchestrating resistance to anti-VEGFA therapy in PNETs.

  15. Silkworm Apolipophorin Protein Inhibits Staphylococcus aureus Virulence*

    Science.gov (United States)

    Hanada, Yuichi; Sekimizu, Kazuhisa; Kaito, Chikara

    2011-01-01

    Silkworm hemolymph inhibits hemolysin production by Staphylococcus aureus. We purified a factor in the silkworm hemolymph responsible for this inhibitory activity. The final fraction with the greatest specific activity contained 220- and 74-kDa proteins. Determination of the N-terminal amino acid sequence revealed that the 220- and 74-kDa proteins were apolipophorin I and apolipophorin II, respectively, indicating that the factor was apolipophorin (ApoLp). The purified ApoLp fraction showed decreased expression of S. aureus hla encoding α-hemolysin, hlb encoding β-hemolysin, saeRS, and RNAIII, which activate the expression of these hemolysin genes. Injection of an anti-ApoLp antibody into the hemolymph increased the sensitivity of silkworms to the lethal effect of S. aureus. Hog gastric mucin, a mammalian homologue of ApoLp, decreased the expression of S. aureus hla and hlb. These findings suggest that ApoLp in the silkworm hemolymph inhibits S. aureus virulence and contributes to defense against S. aureus infection and that its activity is conserved in mammalian mucin. PMID:21937431

  16. Inhibition of Mushroom Tyrosinase Activity by Orsellinates.

    Science.gov (United States)

    Lopes, Thiago Inácio Barros; Coelho, Roberta Gomes; Honda, Neli Kika

    2018-01-01

    Several applications have been proposed for tyrosinase inhibitors in the pharmaceutical, food bioprocessing, and environmental industries. However, only a few compounds are known to serve as effective tyrosinase inhibitors. This study evaluated the tyrosinase-related activity of resorcinol (1), orcinol (2) lecanoric acid (3), and derivatives of this acid (4-15). Subjected to alcoholysis, lecanoric acid (3), a depside isolated from the lichen Parmotrema tinctorum, produces orsellinic acid (2,4-dihydroxy-6-methylbenzoic acid) (4) and orsellinates (2,4-dihydroxy-6-methyl benzoates) (5-15). At 0.50 mM, methyl (5), ethyl (6), n-propyl (7), tert-butyl (11), and n-cetyl orsellinates (15) acted as tyrosinase activators, whereas n-butyl (8), iso-propyl (9), sec-butyl (10), n-pentyl (12), n-hexyl (13), and n-octyl orsellinates (14) behaved as inhibitors. Tyrosinase inhibition rose with chain elongation-n-butyl (8)tyrosinase, with an inhibition constant of 0.99 mM.

  17. Phenols displaying tyrosinase inhibition from Humulus lupulus.

    Science.gov (United States)

    Kim, Dae Wook; Woo, Hyun Sim; Kim, Jeong Yoon; Ryuk, Jin Ah; Park, Ki Hun; Ko, Byoung Seob

    2016-10-01

    Tyrosinase is the rate-limiting enzyme for the production of melanin and other pigments via the oxidation of l-tyrosine. The methanol extract from Humulus lupulus showed potent inhibition against mushroom tyrosinase. The bioactivity-guided fractionation of this methanol extract resulted in the isolation of seven flavonoids (1-7), identified as xanthohumol (1), 4'-O-methylxanthohumol (2), xanthohumol C (3), flavokawain C (4), xanthoumol B (5), 6-prenylnaringenin (6) and isoxanthohumol (7). All isolated flavonoids (1-7) effectively inhibited the monophenolase (IC50s = 15.4-58.4 µM) and diphenolase (IC50s = 27.1-117.4 µM) activities of tyrosinase. Kinetic studies using Lineweaver-Burk and Dixon-plots revealed that chalcones (1-5) were competitive inhibitors, whereas flavanones (6 and 7) exhibited both mixed and non-competitive inhibitory characteristics. In conclusion, this study is the first to demonstrate that the phenolic phytochemicals of H. lupulus display potent inhibitory activities against tyrosinase.

  18. Targeting Sphingosine Kinase-1 To Inhibit Melanoma

    Science.gov (United States)

    Madhunapantula, SubbaRao V.; Hengst, Jeremy; Gowda, Raghavendra; Fox, Todd E.; Yun, Jong K; Robertson, Gavin P.

    2012-01-01

    SUMMARY Resistance to therapies develops rapidly for melanoma leading to more aggressive disease. Therefore, agents are needed that specifically inhibit proteins or pathways controlling the development of this disease, which can be combined, dependent on genes deregulated in a particular patient’s tumors. This study shows that elevated sphingosine-1-phosphate (S-1-P) levels resulting from increased activity of sphingosine kinase-1 (SPHK1) occur in advanced melanomas. Targeting SPHK1 using siRNA decreased anchorage dependent and independent growth as well as sensitized melanoma cells to apoptosis inducing agents. Pharmacological SPHK1 inhibitors SKI-I but not SKI-II decreased S-1-P content, elevated ceramide levels, caused a G2-M block and induced apoptotic cell death in melanomas. Targeting SPHK1 using siRNA or the pharmacological agent called SKI-I, decreased the levels of pAKT. Furthermore, SKI-I inhibited the expression of CYCLIN D1 protein and increased the activity of caspase-3/7, which in turn led to the degradation of PARP. In animals, SKI-I but not SKI-II retarded melanoma growth by 25-40%. Thus, targeting SPHK1 using siRNAs or SKI-I has therapeutic potential for melanoma treatment either alone or in combination with other targeted agents. PMID:22236408

  19. Denitrification inhibition by high nitrate wastes

    International Nuclear Information System (INIS)

    Veydovec, W.; Silverstein, J.; Lehmkuhl, G.D.

    1994-01-01

    The processing of radioactive metal products at nuclear weapons plants and research labs has produced wastewaters containing high concentrations of nitrate, often greater than 50,000 mg/l N. The adaptation of activated sludge and inhibition of denitrification at high nitrate concentrations was studied using pH controlled bench-scale sequencing batch reactors (SBRs), operated with 50% of the SBR volume recycled (recycle volume = influent volume). Denitrification of 1,350 and 2,700 mg/l NO 3 - -N was completed after approximately 5 hours and 15 hours, respectively. No denitrification of 5,400 mg/l NO 3 - -N was observed. These results suggest that there is a progressive inhibition of denitrification as nitrate concentrations increase from 1,350 to 5,400 mg/l NO 3 - -N. In a subsequent series of experiments at an initial reactor nitrate concentration of 1,350 mg/l N, a significant accumulation of nitrate was observed, resulting once in destabilization with loss of denitrification and once in successful adaptation of the activated sludge. At a nitrate concentration of 1,350 mg/l N, the adaptation of activated sludge appears to be unstable, resulting sometimes in stable denitrification and sometimes in biomass washout

  20. Heat enhances radiation inhibition of wound healing

    International Nuclear Information System (INIS)

    Twomey, P.; Hill, S.; Joiner, M.; Hobson, B.; Denekamp, J.

    1987-01-01

    To study the effect of hyperthermia on the inhibition of healing by radiation, the authors used 2 models of wound tensile strength in mice. In one, tensile strength of 1 cm strips of wounded skin was measured. In the other, strength was measured on 2 by 1 by .3 cm surgical prosthetic sponges of polyvinyl alcohol which has been cut, resutured, and implanted subcutaneously. Granulation tissue grows into the pores of the sponges which gradually fill with collagen. Tensile strength in both models was measured on day 14 using a constant strain extensiometer. The wounds were given graduated doses of ortho-voltage radiation with or without hyperthermia. Maximum radiation sensitivity occurred during the period of rapid neovascularization in the first 5 days after wounding, when a loss of 80% in wound strength occurred with doses less than 20 gray. For single radiation doses given 48 hours after wounding, the authors found a steep dose-response curve with half maximum reduction in strength occurring in both models at approximately 10 gray. Hyperthermia was produced in two ways. Skin wounds were heated in a circulating water bath. In the sponge model, more uniform heating occurs with an RF generator scaled to the mouse. At a dose of 43 C for 30 minutes, no inhibition of healing by heat alone was found. However the combination of heat and radiation produced definite enhancement of radiation damage, with thermal enhancement ratios of up to 1.9 being observed

  1. Sprouting inhibition of rhizomes by gamma irradiation

    International Nuclear Information System (INIS)

    Hilmy, Nazly; Chosdu, Rahayu

    1985-01-01

    Sprouting inhibition by gamma irradiation to prolong the storage life of 4 species of rhizomes, namely curcuma domestica, kaemferia galanga, curcuma xanthoriza and curcuma aeruginosa, has been carried out. Two groups of samples were used, freshly harvested rhizomes and fresh rhizomes which have been stored for about two weeks. The samples were packed in a plastic net bag, each contained about 100 grams of rhizomes. Irradiation was carried out at room temperature at the doses of 0, 0.02, 0.04, 0.06, 0.08, 0.10, 0.15, 0.20 and 0.25 kGy. Post irradiation storage was done at room temperature with relative humidity ranging between 85 and 95%. The results showed that irradiation doses of 0.06 to 0.08 kGy was sufficient to inhibit sprouting of freshly harvested rhizomes and prolonged its storage life for 6 weeks, while in the other group sprouting still occured at the dose of 0.25 kGy. Irradiation dose up to 0.25 kGy did not cause significant effect on moisture and volatile oil contents, as well as volatile oil characteristics of the samples. About 50% of weight losses were found either in irradiated or unirradiated samples after being stored for 8 weeks. Odour and texture were evaluated organoleptically while mould growth and insect damage were observed visually. (author)

  2. Tigecycline inhibits proliferation of Acanthamoeba castellanii.

    Science.gov (United States)

    Jha, Bijay Kumar; Seo, Incheol; Kong, Hyun-Hee; Suh, Seong-Il; Suh, Min-Ho; Baek, Won-Ki

    2015-03-01

    Acanthamoeba is an opportunistic protozoan parasite responsible for different diseases in humans, such as granulomatous amoebic encephalitis and amoebic keratitis. Tigecycline, a third-generation tetracycline antibiotic, has potential activity to treat most of the antibiotic resistant bacterial infections. The effects of tigecycline in eukaryotic cells as well as parasites are less well studied. In the present study, we tested the effects of tigecycline on trophozoites of Acanthamoeba castellanii. The inhibitory effect of tigecycline on Acanthamoeba was determined by resazurin reduction and trypan blue exclusion assays. We found that tigecycline significantly inhibited the growth of Acanthamoeba (46.4 % inhibition at the concentration of 100 μM) without affecting cell viability and induction of encystation, whereas other tetracycline groups of antibiotics such as tetracycline and doxycycline showed no inhibitory effects. Furthermore, tigecycline decreased cellular adenosine triphosphate (ATP) level by 26 % than the control and increased mitochondrial mass, suggesting mitochondrial dysfunction in tigecycline-treated cells. These findings suggest that mitochondrial dysfunction with decreased ATP production might play an important mechanism of tigecycline in suppression of Acanthamoeba proliferation.

  3. Inhibition of dioscin on Saprolegnia in vitro.

    Science.gov (United States)

    Liu, Lei; Shen, Yu-Feng; Liu, Guang-Lu; Ling, Fei; Liu, Xin-Yang; Hu, Kun; Yang, Xian-Le; Wang, Gao-Xue

    2015-12-01

    As one of the most serious pathogens in the freshwater aquatic environment, Saprolegnia can induce a high mortality rate during the fish egg incubation period. This study investigated the anti-Saprolegnia activity of a total of 108 plants on Saprolegnia parasitica in vitro and Dioscorea collettii was selected for further studies. By loading on an open silica gel column and eluting with petroleum ether-ethyl acetate-methanol, dioscin (C45H72O16) was isolated from D. collettii. Saprolegnia parasitica growth was inhibited significantly when dioscin concentration was more than 2.0 mg L(-1). When compared with formalin and hydrogen peroxide, dioscin showed a higher inhibitory effect. As potential inhibition mechanisms, dioscin could cause the S. parasitica mycelium morphologic damage, dense folds, or disheveled protuberances observed by field emission scanning electron microscopy and the influx of Propidium iodide. The structural changes in the treated mycelium were indicative of an efficient anti-Saprolegnia activity of dioscin. The oxidative stress results showed that dioscin also accumulated reactive oxygen species excessively and increased total antioxidant and superoxide dismutase activity. These situations could render S. parasitica more vulnerable to oxidative damage. Additionally, when dioscin concentration was less than 2.0 mg L(-1), the survival rate of embryos was more than 70%. Therefore, the use of dioscin could be a viable way of preventing and controlling saprolegniasis. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Inhibition of DNA replication by ultraviolet light

    Energy Technology Data Exchange (ETDEWEB)

    Edenberg, H.J.

    1976-08-01

    DNA replication in ultraviolet-irradiated HeLa cells was studied by two different techniques: measurements of the kinetics of semiconservative DNA synthesis, and DNA fiber autoradiography. In examining the kinetics of semiconservative DNA synthesis, density label was used to avoid measuring the incorporation due to repair replication. The extent of inhibition varied with time. After doses of less than 10 J/m/sup 2/ the rate was initially depressed but later showed some recovery. After higher doses, a constant, low rate of synthesis was seen for at least the initial 6 h. An analysis of these data indicated that the inhibition of DNA synthesis could be explained by replication forks halting at pyrimidine dimers. DNA fiber autoradiography was used to further characterize replication after ultraviolet irradiation. The average length of labeled segments in irradiated cells increased in the time immediately after irradiation, and then leveled off. This is the predicted pattern if DNA synthesis in each replicon continued at its previous rate until a lesion is reached, and then halted. The frequency of lesions that block synthesis is approximately the same as the frequency of pyrimidine dimers.

  5. Inhibition by acrolein of light-induced stomatal opening through inhibition of inward-rectifying potassium channels in Arabidopsis thaliana.

    Science.gov (United States)

    Islam, Md Moshiul; Ye, Wenxiu; Matsushima, Daiki; Khokon, Md Atiqur Rahman; Munemasa, Shintaro; Nakamura, Yoshimasa; Murata, Yoshiyuki

    2015-01-01

    Acrolein is a reactive α,β-unsaturated aldehyde derived from lipid peroxides, which are produced in plants under a variety of stress. We investigated effects of acrolein on light-induced stomatal opening using Arabidopsis thaliana. Acrolein inhibited light-induced stomatal opening in a dose-dependent manner. Acrolein at 100 μM inhibited plasma membrane inward-rectifying potassium (Kin) channels in guard cells. Acrolein at 100 μM inhibited Kin channel KAT1 expressed in a heterologous system using Xenopus leaves oocytes. These results suggest that acrolein inhibits light-induced stomatal opening through inhibition of Kin channels in guard cells.

  6. Inhibition of tyrosinase by fumaric acid: Integration of inhibition kinetics with computational docking simulations.

    Science.gov (United States)

    Gou, Lin; Lee, Jinhyuk; Yang, Jun-Mo; Park, Yong-Doo; Zhou, Hai-Meng; Zhan, Yi; Lü, Zhi-Rong

    2017-12-01

    Fumaric acid (FA), which is naturally found in organisms, is a well known intermediate of the citric acid cycle. We evaluated the effects of FA on tyrosinase activity and structure via enzyme kinetics and computational simulations. FA was found to be a reversible inhibitor of tyrosinase and its induced mechanism was the parabolic non-competitive inhibition type with IC 50 =13.7±0.25mM and K i slope =12.64±0.75mM. We newly established the equation for the dissociation constant (K islope ) for the parabolic inhibition type in this study. Kinetic measurements and spectrofluorimetry studies showed that FA induced regional changes in the active site of tyrosinase. One possible binding site for FA was identified under the condition without L-DOPA. The computational docking simulations further revealed that FA can interact with HIS263 and HIS85 at the active site. Furthermore, four important hydrogen bonds were found to be involved with the docking of FA on tyrosinase. Our study provides insight into the mechanism by which dicarboxylic acids such as FA inhibit tyrosinase. By inhibiting tyrosinase and its central role in pigment production, FA is a potential natural antipigmentation agent. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Distinct Neural Correlates for Two Types of Inhibition in Bilinguals: Response Inhibition versus Interference Suppression

    Science.gov (United States)

    Luk, Gigi; Anderson, John A. E.; Craik, Fergus I. M.; Grady, Cheryl; Bialystok, Ellen

    2010-01-01

    To examine the effects of bilingualism on cognitive control, we studied monolingual and bilingual young adults performing a flanker task with functional MRI. The trial types of primary interest for this report were incongruent and no-go trials, representing interference suppression and response inhibition, respectively. Response times were similar…

  8. Ketoconazole inhibits the cellular uptake of anandamide via inhibition of FAAH at pharmacologically relevant concentrations.

    Directory of Open Access Journals (Sweden)

    Emmelie Björklund

    Full Text Available The antifungal compound ketoconazole has, in addition to its ability to interfere with fungal ergosterol synthesis, effects upon other enzymes including human CYP3A4, CYP17, lipoxygenase and thromboxane synthetase. In the present study, we have investigated whether ketoconazole affects the cellular uptake and hydrolysis of the endogenous cannabinoid receptor ligand anandamide (AEA.The effects of ketoconazole upon endocannabinoid uptake were investigated using HepG2, CaCo2, PC-3 and C6 cell lines. Fatty acid amide hydrolase (FAAH activity was measured in HepG2 cell lysates and in intact C6 cells. Ketoconazole inhibited the uptake of AEA by HepG2 cells and CaCo2 cells with IC50 values of 17 and 18 µM, respectively. In contrast, it had modest effects upon AEA uptake in PC-3 cells, which have a low expression of FAAH. In cell-free HepG2 lysates, ketoconazole inhibited FAAH activity with an IC50 value (for the inhibitable component of 34 µM.The present study indicates that ketoconazole can inhibit the cellular uptake of AEA at pharmacologically relevant concentrations, primarily due to its effects upon FAAH. Ketoconazole may be useful as a template for the design of dual-action FAAH/CYP17 inhibitors as a novel strategy for the treatment of prostate cancer.

  9. Ganoderic acid T inhibits tumor invasion in vitro and in vivo through inhibition of MMP expression.

    Science.gov (United States)

    Chen, Nian-Hong; Liu, Jian-Wen; Zhong, Jian-Jiang

    2010-01-01

    The traditional Chinese medicinal mushroom, Ganoderma lucidum, has been used in Asia for several thousand years for the prevention and treatment of a variety of diseases, including cancer. In previous work, we purified ganoderic acid T (GA-T) from G. lucidum [28]. In the present study, we investigate the functions of GA-T in terms of its effects on invasion in vitro and metastasis in vivo. A trypan blue dye exclusion assay indicates that GA-T inhibits proliferation of HCT-116 cells, a human colon carcinoma cell line. Cell aggregation and adhesion assays show that GA-T promotes homotypic aggregation and simultaneously inhibits the adhesion of HCT-116 cells to the extracellular matrix (ECM) in a dose-dependent manner.Wound healing assays indicate that GA-T also inhibits the migration of HCT-116 cells in a dose-dependent manner, and it suppresses the migration of 95-D cells, a highly metastatic human lung tumor cell line, in a dose- and time-dependent manner. In addition, GA-T inhibits the nuclear translocation of nuclear factor-kappaB (NF-kappaB) and the degradation of inhibitor of kappaB-alpha (IkappaBalpha), which leads to down-regulated expression of matrix metalloproteinase-9 (MMP-9), inducible nitric oxide synthase (iNOS), and urokinase-type plasminogen activator (uPA). Animal and Lewis Lung Carcinoma (LLC) model experiments demonstrate that GA-T suppresses tumor growth and LLC metastasis and down-regulates MMP-2 and MMP-9 mRNA expression in vivo. Taken together, these results demonstrate that GA-T effectively inhibits cancer cell invasion in vitro and metastasis in vivo, and thus it may act as a potential drug for treating cancer.

  10. Equol inhibits growth, induces atresia, and inhibits steroidogenesis of mouse antral follicles in vitro

    Science.gov (United States)

    Mahalingam, Sharada; Gao, Liying; Gonnering, Marni; Helferich, William; Flaws, Jodi A.

    2016-01-01

    Equol is a non-steroidal estrogen metabolite produced by microbial conversion of daidzein, a major soy isoflavone, in the gut of some humans and many animal species. Isoflavones and their metabolites can affect endogenous estradiol production, action, and metabolism, potentially influencing ovarian follicle function. However, no studies have examined the effects of equol on intact ovarian antral follicles, which are responsible for sex steroid synthesis and further development into ovulatory follicles. Thus, the present study tested the hypothesis that equol inhibits antral follicle growth, increases follicle atresia, and inhibits steroidogenesis in the adult mouse ovary. To test this hypothesis, antral follicles isolated from adult CD-1 mice were cultured with vehicle control (dimethyl sulfoxide; DMSO) or equol (600 nM, 6 μM, 36 μM, 100 μM) for 48 and 96 h. Every 24 h, follicle diameters were measured to monitor growth. At 48 and 96 h, the culture medium was subjected to measurement of hormone levels, and the cultured follicles were subjected to gene expression analysis. Additionally, follicles were histologically evaluated for signs of atresia after 96 h of culture. The results indicate that equol (100 μM) inhibited follicle growth, altered the mRNA levels of bcl2-associated X protein and B cell leukemia/lymphoma 2, and induced follicle atresia. Further, equol decreased the levels of estradiol, testosterone, androstenedione, and progesterone, and it decreased mRNA levels of cholesterol side-chain cleavage, steroid 17-α-hydroxalase, and aromatase. Collectively, these data indicate that equol inhibits growth, increases atresia, and inhibits steroidogenesis of cultured mouse antral follicles. PMID:26876617

  11. Inhibition experiments on anaerobic methane oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Alperin, M.J.; Reeburgh, W.S.

    1985-10-01

    Anaerobic methane oxidation is a general process important in controlling fluxes of methane from anoxic marine sediments. The responsible organism has not been isolated, and little is known about the electron acceptors and substrates involved in the process. Laboratory evidence indicates that sulfate reducers and methanogens are able to oxidize small quantities of methane. Field evidence suggests anaerobic methane oxidation may be linked to sulfate reduction. Experiments with specific inhibitors for sulfate reduction (molybdate), methanogenesis (2-bromoethanesulfonic acid), and acetate utilization (fluoroacetate) were performed on marine sediments from the zone of methane oxidation to determine whether sulfate-reducing bacteria or methanogenic bacteria are responsible for methane oxidation. The inhibition experiment results suggest that methane oxidation in anoxic marine sediments is not directly mediated by sulfate-reducing bacteria or methanogenic bacteria. Our results are consistent with two possibilities: anaerobic methane oxidation may be mediated by an unknown organism or a consortium involving an unknown methane oxidizer and sulfate-reducing bacteria.

  12. Diclofenac inhibits 27-hydroxycholesterol-induced inflammation.

    Science.gov (United States)

    Kim, Bo-Young; Son, Yonghae; Eo, Seong-Kug; Park, Young Chul; Kim, Koanhoi

    2016-09-23

    27-Hydroxycholesterol (27OHChol) is a cholesterol oxidation product that induces inflammation. In the current study we investigated the effects of diclofenac on inflammatory responses caused by 27OHChol using human monocyte/macrophage (THP-1) cells. Transcription and secretion of CCL2, CCL3, and CCL4 chemokines enhanced by 27OHChol were significantly attenuated by diclofenac in a concentration dependent manner. Migrations of monocytic cells and CCR5-positive Jurkat T cells were reduced proportionally to the concentrations of diclofenac. Superproduction of CCL2 and monocytic cell migration induced by 27OHChol plus LPS were significantly attenuated by diclofenac. Diclofenac also attenuated transcription of MMP-9 and release of its active gene product. These results indicate that diclofenac inhibits 27OHChol-induced inflammatory responses, thereby suppressing inflammation in a milieu rich in cholesterol oxidation products. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Inhibition effect of food preservatives on endoproteinases.

    Science.gov (United States)

    Esimbekova, Elena N; Asanova, Anastasiya A; Deeva, Anna A; Kratasyuk, Valentina A

    2017-11-15

    The present manuscript proposes a novel approach to assess the impact of food additives on human metabolism by analysing their effect on biomarker enzyme activity. Alterations in the activity of pancreatic enzymes, such as chymotrypsin and trypsin, which are affected by the most common food preservatives, sodium benzoate (E211), potassium sorbate (E202) and sorbic acid (E200), have been evaluated. The proteinase activity was analysed with a bioluminescent method using the light intensity decay constant. Our study revealed that the preservatives reduce proteinase activity by 50% (EC 50 ) at a much lower concentration than their acceptable daily intake (ADI). Thus, sodium benzoate and sorbic acid have an inhibition effect on chymotrypsin at concentrations 14 times lower and 70 times lower than their ADI and this increases with exposure time. Food preservative consumption impacts negatively on protein digestion, which is especially dangerous for patients with pancreatitis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Competitive inhibition of glutamate dehydrogenase reaction.

    Science.gov (United States)

    Choudhury, Rajarshi; Punekar, Narayan S

    2007-06-12

    Irrespective of their pyridine nucleotide specificity, all glutamate dehydrogenases share a common chemical mechanism that involves an enzyme bound 'iminoglutarate' intermediate. Three compounds, structurally related to this intermediate, were tested for the inhibition of purified NADP-glutamate dehydrogenases from two Aspergilli, as also the bovine liver NAD(P)-glutamate dehydrogenase. 2-Methyleneglutarate, closely resembling iminoglutarate, was a potent competitive inhibitor of the glutamate dehydrogenase reaction. This is the first report of a non-aromatic structure with a better glutamate dehydrogenase inhibitory potency than aryl carboxylic acids such as isophthalate. A suitably located 2-methylene group to mimic the iminium ion could be exploited to design inhibitors of other amino acid dehydrogenases.

  15. Erasing sensorimotor memories via PKMzeta inhibition.

    Directory of Open Access Journals (Sweden)

    Lee Michael von Kraus

    2010-06-01

    Full Text Available Sensorimotor cortex has a role in procedural learning. Previous studies suggested that this learning is subserved by long-term potentiation (LTP, which is in turn maintained by the persistently active kinase, protein kinase Mzeta (PKMzeta. Whereas the role of PKMzeta in animal models of declarative knowledge is established, its effect on procedural knowledge is not well understood. Here we show that PKMzeta inhibition, via injection of zeta inhibitory peptide (ZIP into the rat sensorimotor cortex, disrupts sensorimotor memories for a skilled reaching task even after several weeks of training. The rate of relearning the task after the memory disruption by ZIP was indistinguishable from the rate of initial learning, suggesting no significant savings after the memory loss. These results indicate a shared molecular mechanism of storage for declarative and procedural forms of memory.

  16. Erasing Sensorimotor Memories via PKMζ Inhibition

    Science.gov (United States)

    von Kraus, Lee Michael; Sacktor, Todd Charlton; Francis, Joseph Thachil

    2010-01-01

    Sensorimotor cortex has a role in procedural learning. Previous studies suggested that this learning is subserved by long-term potentiation (LTP), which is in turn maintained by the persistently active kinase, protein kinase Mzeta (PKMζ). Whereas the role of PKMζ in animal models of declarative knowledge is established, its effect on procedural knowledge is not well understood. Here we show that PKMζ inhibition, via injection of zeta inhibitory peptide (ZIP) into the rat sensorimotor cortex, disrupts sensorimotor memories for a skilled reaching task even after several weeks of training. The rate of relearning the task after the memory disruption by ZIP was indistinguishable from the rate of initial learning, suggesting no significant savings after the memory loss. These results indicate a shared molecular mechanism of storage for declarative and procedural forms of memory. PMID:20559553

  17. Erasing sensorimotor memories via PKMzeta inhibition.

    Science.gov (United States)

    von Kraus, Lee Michael; Sacktor, Todd Charlton; Francis, Joseph Thachil

    2010-06-15

    Sensorimotor cortex has a role in procedural learning. Previous studies suggested that this learning is subserved by long-term potentiation (LTP), which is in turn maintained by the persistently active kinase, protein kinase Mzeta (PKMzeta). Whereas the role of PKMzeta in animal models of declarative knowledge is established, its effect on procedural knowledge is not well understood. Here we show that PKMzeta inhibition, via injection of zeta inhibitory peptide (ZIP) into the rat sensorimotor cortex, disrupts sensorimotor memories for a skilled reaching task even after several weeks of training. The rate of relearning the task after the memory disruption by ZIP was indistinguishable from the rate of initial learning, suggesting no significant savings after the memory loss. These results indicate a shared molecular mechanism of storage for declarative and procedural forms of memory.

  18. Inhibition of maintenance DNA methylation by Stella.

    Science.gov (United States)

    Funaki, Soichiro; Nakamura, Toshinobu; Nakatani, Tsunetoshi; Umehara, Hiroki; Nakashima, Hiroyuki; Nakano, Toru

    2014-10-24

    DNA methylation is a key epigenetic regulator in mammals, and the dynamic balance between methylation and demethylation impacts various processes, from development to disease. DNA methylation is erased during replication when DNA methyltransferase 1 (DNMT1) fails to methylate the daughter strand, in a process known as passive DNA demethylation. We found that the enforced expression of Stella (also known as PGC7, Dppa3), a maternal factor required for the maintenance of DNA methylation in early embryos, induced global DNA demethylation in NIH3T3 cells. This demethylation was caused by the binding of Stella to Np95 (also known as Uhrf1, ICBP90) and the subsequent inhibition of DNMT1 recruitment. Considering that impaired DNA methylation profiles are associated with various developmental or disease phenomena, Stella may be a powerful tool with which to study the biological effects of global DNA hypomethylation. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Linking algal growth inhibition to chemical activity

    DEFF Research Database (Denmark)

    Schmidt, Stine N.; Mayer, Philipp

    2015-01-01

    Recently, high-quality data were published on the algal growth inhibition caused by 50 non-polar narcotic compounds, of which 39 were liquid compounds with defined water solubility. In the present study, the toxicity data for these liquids were applied to challenge the chemical activity range...... for baseline toxicity. First, the reported effective concentrations (EC50) were divided by the respective water solubilities (Swater), since the obtained EC50/Swater ratio essentially equals the effective chemical activity (Ea50). The majority of EC50/Swater ratios were within the expected chemical activity...... solubility in the applied dataset. On an environmental risk assessment level, predicted no-effect concentrations (PNECs) for baseline toxicity could even be set as a percentage of saturation, which can easily be extended to mixtures. However, EC50 values well below 1% of liquid saturation can still occur...

  20. Spice phenolics inhibit human PMNL 5-lipoxygenase.

    Science.gov (United States)

    Prasad, N Satya; Raghavendra, R; Lokesh, B R; Naidu, K Akhilender

    2004-06-01

    A wide variety of phenolic compounds and flavonoids present in spices possess potent antioxidant, antimutagenic and anticarcinogenic activities. We examined whether 5-lipoxygenase (5-LO), the key enzyme involved in biosynthesis of leukotrienes is a possible target for the spices. Effect of aqueous extracts of turmeric, cloves, pepper, chili, cinnamon, onion and also their respective active principles viz., curcumin, eugenol, piperine, capsaicin, cinnamaldehyde, quercetin, and allyl sulfide were tested on human PMNL 5-LO activity by spectrophotomeric and HPLC methods. The formation of 5-LO product 5-HETE was significantly inhibited in a concentration-dependent manner with IC(50) values of 0.122-1.44 mg for aqueous extracts of spices and 25-83 microM for active principles, respectively. The order of inhibitory activity was of quercetin>eugenol>curcumin>cinnamaldehyde>piperine>capsaicin>allyl sulfide. Quercetin, eugenol and curcumin with one or more phenolic ring and methoxy groups in their structure showed high inhibitory effect, while the non-phenolic spice principle allyl sulfide showed least inhibitory effect on 5-LO. The inhibitory effect of quercetin, curcumin and eugenol was similar to that of synthetic 5-LO inhibitors-phenidone and NDGA. Moreover, the inhibitory potency of aqueous extracts of spice correlated with the active principles of their respective spices. The synergistic or antagonistic effect of mixtures of spice active principles and spice extracts were investigated and all the combinations of spice active principles/extracts exerted synergistic effect in inhibiting 5-LO activity. These findings clearly suggest that phenolic compounds present in spices might have physiological role in modulating 5-LO pathway.

  1. Inhibition of photosynthesis by a fluoroquinolone antibiotic.

    Science.gov (United States)

    Aristilde, Ludmilla; Melis, Anastasios; Sposito, Garrison

    2010-02-15

    Recent microcosm studies have revealed that fluoroquinolone (FQ) antibiotics can have ecotoxicological impacts on photosynthetic organisms, but little is known about the mechanisms of toxicity. We employed a combination of modeling and experimental techniques to explore how FQs may have these unintended secondary toxic effects. Structure-activity analysis revealed that the quinolone ring and secondary amino group typically present in FQ antibiotics may mediate their action as quinone site inhibitors in photosystem II (PS-II), a key enzyme in photosynthetic electron transport. Follow-up molecular simulations involving nalidixic acid (Naldx), a nonfluorinated quinolone with a demonstrated adverse impact on photosynthesis, and ciprofloxacin (Cipro), the most commonly used FQ antibiotic, showed that both may interfere stereochemically with the catalytic activity of reaction center II (RC-II), the pheophytin-quinone-type center present in PS-II. Naldx can occupy the same binding site as the secondary quinone acceptor (Q(B)) in RC-II and interact with amino acid residues required for the enzymatic reduction of Q(B). Cipro binds in a somewhat different manner, suggesting a different mechanism of interference. Fluorescence induction kinetics, a common method of screening for PS-II inhibition, recorded for photoexcited thylakoid membranes isolated from Cipro-exposed spinach chloroplasts, indicated that Cipro interferes with the transfer of energy from excited antenna chlorophyll molecules to the reaction center in RC-II ([Cipro] >or= 5 microM in vitro and >or=10 microM in vivo) and thus delays the kinetics of photoreduction of the primary quinone acceptor (Q(A); [Cipro] >or= 0.6 microM in vitro). Spinach plants exposed to Cipro exhibited severe growth inhibition characterized by a decrease in both the synthesis of leaves and growth of the roots ([Cipro] >or= 0.5 microM in vivo). Our results thus demonstrate that Cipro and related FQ antibiotics may interfere with

  2. Task Inhibition and Response Inhibition in Older versus Younger Adults: A Diffusion Model Analysis

    Directory of Open Access Journals (Sweden)

    Stefanie Schuch

    2016-11-01

    Full Text Available Differences in inhibitory ability between older (64-79 years, N=24 and younger adults (18-26 years, N =24 were investigated using a diffusion model analysis. Participants performed a task-switching paradigm that allows assessing n-2 task repetition costs, reflecting inhibitory control on the level of tasks, as well as n-1 response-repetition costs, reflecting inhibitory control on the level of responses. N-2 task repetition costs were of similar size in both age groups. Diffusion model analysis revealed that for both younger and older adults, drift rate parameters were smaller in the inhibition condition relative to the control condition, consistent with the idea that persisting task inhibition slows down response selection. Moreover, there was preliminary evidence for task inhibition effects in threshold separation and non-decision time in the older, but not the younger adults, suggesting that older adults might apply different strategies when dealing with persisting task inhibition. N-1 response-repetition costs in mean RT tended to be larger in older than younger adults, but in mean error rates were larger in younger than older adults. Diffusion-model analysis revealed longer non-decision times in response repetitions than response switches in both age groups, consistent with the idea that motor processes take longer in response repetitions than response switches due to persisting response inhibition of a previously executed response. The data also revealed age-related differences in overall performance: Older adults responded more slowly and more accurately than young adults, which was reflected by a higher threshold separation parameter in diffusion model analysis. Moreover, older adults showed larger non-decision times and higher variability in non-decision time than young adults, possibly reflecting slower and more variable motor processes. In contrast, overall drift rate did not differ between older and younger adults. Taken together

  3. Effects of flavonoid mixtures on the transport of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) through Caco-2 monolayers: An in vitro and kinetic modeling approach to predict the combined effects on transporter inhibition

    NARCIS (Netherlands)

    Schutte, M.E.; Boersma, M.G.; Verhallen, D.A.M.; Groten, J.P.; Rietjens, I.M.C.M.

    2008-01-01

    This study describes and kinetically models the effect of flavonoid mixtures on PhIP transport through Caco-2 monolayers. Previously it was shown that quercetin, luteolin, naringenin and myricetin increase the apical to basolateral PhIP transport in Caco-2 monolayers. In this study, apigenin was

  4. Effects of flavonoid mixtures on the transport of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) through Caco-2 monolayers: an in vitro and a kinetic modeling approach to predict the combined effects on transporter inhibition

    NARCIS (Netherlands)

    Schutte, M.E.; Boersma, M.G.; Verhallen, D.A.M.; Groten, J.P.; Rietjens, I.M.C.M.

    2008-01-01

    This study describes and kinetically models the effect of flavonoid mixtures on PhIP transport through Caco-2 monolayers. Previously it was shown that quercetin, luteolin, naringenin and myricetin increase the apical to basolateral PhIP transport in Caco-2 monolayers. In this study, apigenin was

  5. High molecular weight polysaccharide that binds and inhibits virus

    Energy Technology Data Exchange (ETDEWEB)

    Konowalchuk, Thomas W.; Konowalchuk, Jack

    2017-07-18

    This invention provides a high molecular weight polysaccharide capable of binding to and inhibiting virus and related pharmaceutical formulations and methods of inhibiting viral infectivity and/or pathogenicity, as well as immunogenic compositions. The invention further includes methods of inhibiting the growth of cancer cells and of ameliorating a symptom of aging. Additionally, the invention provides methods of detecting and/or quantifying and/or isolating viruses.

  6. High molecular weight polysaccharide that binds and inhibits virus

    Science.gov (United States)

    Konowalchuk, Thomas W

    2014-01-14

    This invention provides a high molecular weight polysaccharide capable of binding to and inhibiting virus and related pharmaceutical formulations and methods on inhibiting viral infectivity and/or pathogenicity, as well as immunogenic compositions. The invention further methods of inhibiting the growth of cancer cells and of ameliorating a symptom of aging. Additionally, the invention provides methods of detecting and/or quantifying and/or isolating viruses.

  7. Timing of growth inhibition following shoot inversion in Pharbitis nil

    Science.gov (United States)

    Abdel-Rahman, A. M.; Cline, M. G.

    1989-01-01

    Shoot inversion in Pharbitis nil results in the enhancement of ethylene production and in the inhibition of elongation in the growth zone of the inverted shoot. The initial increase in ethylene production previously was detected within 2 to 2.75 hours after inversion. In the present study, the initial inhibition of shoot elongation was detected within 1.5 to 4 hours with a weighted mean of 2.4 hours. Ethylene treatment of upright shoots inhibited elongation in 1.5 hours. A cause and effect relationship between shoot inversion-enhanced ethylene production and inhibition of elongation cannot be excluded.

  8. Effect of thione–thiol tautomerism on the inhibition of ...

    Indian Academy of Sciences (India)

    WINTEC

    ; bioinorganic chemistry; enzyme inhibition; lactoperoxidase; methimazole. 1. Introduction. The heme peroxidase superfamily of 'mammalian peroxidases' include lactoperoxidase (LPO), mye- loperoxidase (MPO), eosinophil peroxidase (EPO).

  9. Allosteric inhibition of SHP2 phosphatase inhibits cancers driven by receptor tyrosine kinases

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying-Nan P.; LaMarche, Matthew J.; Chan, Ho Man; Fekkes, Peter; Garcia-Fortanet, Jorge; Acker, Michael G.; Antonakos, Brandon; Chen, Christine Hiu-Tung; Chen, Zhouliang; Cooke, Vesselina G.; Dobson, Jason R.; Deng, Zhan; Fei, Feng; Firestone, Brant; Fodor, Michelle; Fridrich, Cary; Gao, Hui; Grunenfelder, Denise; Hao, Huai-Xiang; Jacob, Jaison; Ho, Samuel; Hsiao, Kathy; Kang, Zhao B.; Karki, Rajesh; Kato, Mitsunori; Larrow, Jay; La Bonte, Laura R.; Lenoir, Francois; Liu, Gang; Liu, Shumei; Majumdar, Dyuti; Meyer, Matthew J.; Palermo, Mark; Perez, Lawrence; Pu, Minying; Price, Edmund; Quinn, Christopher; Shakya, Subarna; Shultz, Michael D.; Slisz, Joanna; Venkatesan, Kavitha; Wang, Ping; Warmuth, Markus; Williams, Sarah; Yang, Guizhi; Yuan, Jing; Zhang, Ji-Hu; Zhu, Ping; Ramsey, Timothy; Keen, Nicholas J.; Sellers, William R.; Stams, Travis; Fortin , Pascal D. (Novartis)

    2016-06-29

    The non-receptor protein tyrosine phosphatase SHP2, encoded by PTPN11, has an important role in signal transduction downstream of growth factor receptor signalling and was the first reported oncogenic tyrosine phosphatase1. Activating mutations of SHP2 have been associated with developmental pathologies such as Noonan syndrome and are found in multiple cancer types, including leukaemia, lung and breast cancer and neuroblastoma1, 2, 3, 4, 5. SHP2 is ubiquitously expressed and regulates cell survival and proliferation primarily through activation of the RAS–ERK signalling pathway2, 3. It is also a key mediator of the programmed cell death 1 (PD-1) and B- and T-lymphocyte attenuator (BTLA) immune checkpoint pathways6, 7. Reduction of SHP2 activity suppresses tumour cell growth and is a potential target of cancer therapy8, 9. Here we report the discovery of a highly potent (IC50 = 0.071 μM), selective and orally bioavailable small-molecule SHP2 inhibitor, SHP099, that stabilizes SHP2 in an auto-inhibited conformation. SHP099 concurrently binds to the interface of the N-terminal SH2, C-terminal SH2, and protein tyrosine phosphatase domains, thus inhibiting SHP2 activity through an allosteric mechanism. SHP099 suppresses RAS–ERK signalling to inhibit the proliferation of receptor-tyrosine-kinase-driven human cancer cells in vitro and is efficacious in mouse tumour xenograft models. Together, these data demonstrate that pharmacological inhibition of SHP2 is a valid therapeutic approach for the treatment of cancers.

  10. Hedgehog pathway inhibition in chondrosarcoma using the smoothened inhibitor IPI-926 directly inhibits sarcoma cell growth.

    Science.gov (United States)

    Campbell, Veronica T; Nadesan, Puviindran; Ali, S Amanda; Wang, Chang Ye Yale; Whetstone, Heather; Poon, Raymond; Wei, Qingxia; Keilty, John; Proctor, Jennifer; Wang, Lauren W; Apte, Suneel S; McGovern, Karen; Alman, Benjamin A; Wunder, Jay S

    2014-05-01

    Hedgehog (Hh) pathway inhibition in cancer has been evaluated in both the ligand-independent and ligand-dependent settings, where Hh signaling occurs either directly within the cancer cells or within the nonmalignant cells of the tumor microenvironment. Chondrosarcoma is a malignant tumor of cartilage in which there is ligand-dependent activation of Hh signaling. IPI-926 is a potent, orally delivered small molecule that inhibits Hh pathway signaling by binding to Smoothened (SMO). Here, the impact of Hh pathway inhibition on primary chondrosarcoma xenografts was assessed. Mice bearing primary human chondrosarcoma xenografts were treated with IPI-926. The expression levels of known Hh pathway genes, in both the tumor and stroma, and endpoint tumor volumes were measured. Gene expression profiling of tumors from IPI-926-treated mice was conducted to identify potential novel Hh target genes. Hh target genes were studied to determine their contribution to the chondrosarcoma neoplastic phenotype. IPI-926 administration results in downmodulation of the Hh pathway in primary chondrosarcoma xenografts, as demonstrated by evaluation of the Hh target genes GLI1 and PTCH1, as well as inhibition of tumor growth. Chondrosarcomas exhibited autocrine and paracrine Hh signaling, and both were affected by IPI-926. Decreased tumor growth is accompanied by histopathologic changes, including calcification and loss of tumor cells. Gene profiling studies identified genes differentially expressed in chondrosarcomas following IPI-926 treatment, one of which, ADAMTSL1, regulates chondrosarcoma cell proliferation. These studies provide further insight into the role of the Hh pathway in chondrosarcoma and provide a scientific rationale for targeting the Hh pathway in chondrosarcoma.

  11. Linalool inhibits cigarette smoke-induced lung inflammation by inhibiting NF-κB activation.

    Science.gov (United States)

    Ma, Jianqun; Xu, Hai; Wu, Jun; Qu, Changfa; Sun, Fenglin; Xu, Shidong

    2015-12-01

    Linalool, a natural compound that exists in the essential oils of several aromatic plants species, has been reported to have anti-inflammatory effects. However, the effects of linalool on cigarette smoke (CS)-induced acute lung inflammation have not been reported. In the present study, we investigated the protective effects of linalool on CS-induced acute lung inflammation in mice. Linalool was given i.p. to mice 2h before CS exposure daily for five consecutive days. The numbers of macrophages and neutrophils in bronchoalveolar lavage fluid (BALF) were measured. The production of TNF-α, IL-6, IL-1β, IL-8 and MCP-1 were detected by ELISA. The expression of NF-κB was detected by Western blotting. Our results showed that treatment of linalool significantly attenuated CS-induced lung inflammation, coupled with inhibited the infiltration of inflammatory cells and TNF-α, IL-6, IL-1β, IL-8 and MCP-1 production. Meanwhile, treatment of linalool inhibited CS-induced lung MPO activity and pathological changes. Furthermore, linalool suppressed CS-induced NF-κB activation in a dose-dependent manner. In conclusion, our results demonstrated that linalool protected against CS-induced lung inflammation through inhibiting CS-induced NF-κB activation. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Imeglimin prevents human endothelial cell death by inhibiting mitochondrial permeability transition without inhibiting mitochondrial respiration.

    Science.gov (United States)

    Detaille, D; Vial, G; Borel, A-L; Cottet-Rouselle, C; Hallakou-Bozec, S; Bolze, S; Fouqueray, P; Fontaine, E

    2016-01-01

    Imeglimin is the first in a new class of oral glucose-lowering agents, having recently completed its phase 2b trial. As Imeglimin did show a full prevention of β-cell apoptosis, and since angiopathy represents a major complication of diabetes, we studied Imeglimin protective effects on hyperglycemia-induced death of human endothelial cells (HMEC-1). These cells were incubated in several oxidative stress environments (exposure to high glucose and oxidizing agent tert-butylhydroperoxide) which led to mitochondrial permeability transition pore (PTP) opening, cytochrome c release and cell death. These events were fully prevented by Imeglimin treatment. This protective effect on cell death occurred without any effect on oxygen consumption rate, on lactate production and on cytosolic redox or phosphate potentials. Imeglimin also dramatically decreased reactive oxygen species production, inhibiting specifically reverse electron transfer through complex I. We conclude that Imeglimin prevents hyperglycemia-induced cell death in HMEC-1 through inhibition of PTP opening without inhibiting mitochondrial respiration nor affecting cellular energy status. Considering the high prevalence of macrovascular and microvascular complications in type 2 diabetic subjects, these results together suggest a potential benefit of Imeglimin in diabetic angiopathy.

  13. Inhibition of lignin-derived phenolic compounds to cellulase.

    Science.gov (United States)

    Qin, Lei; Li, Wen-Chao; Liu, Li; Zhu, Jia-Qing; Li, Xia; Li, Bing-Zhi; Yuan, Ying-Jin

    2016-01-01

    Lignin-derived phenolic compounds are universal in the hydrolysate of pretreated lignocellulosic biomass. The phenolics reduce the efficiency of enzymatic hydrolysis and increase the cost of ethanol production. We investigated inhibition of phenolics on cellulase during enzymatic hydrolysis using vanillin as one of the typical lignin-derived phenolics and Avicel as cellulose substrate. As vanillin concentration increased from 0 to 10 mg/mL, cellulose conversion after 72-h enzymatic hydrolysis decreased from 53 to 26 %. Enzyme deactivation and precipitation were detected with the vanillin addition. The enzyme concentration and activity consecutively decreased during hydrolysis, but the inhibition degree, expressed as the ratio of the cellulose conversion without vanillin to the conversion with vanillin (A 0 /A), was almost independent on hydrolysis time. Inhibition can be mitigated by increasing cellulose loading or cellulase concentration. The inhibition degree showed linear relationship with the vanillin concentration and exponential relationship with the cellulose loading and the cellulase concentration. The addition of calcium chloride, BSA, and Tween 80 did not release the inhibition of vanillin significantly. pH and temperature for hydrolysis also showed no significant impact on inhibition degree. The presence of hydroxyl group, carbonyl group, and methoxy group in phenolics affected the inhibition degree. Besides phenolics concentration, other factors such as cellulose loading, enzyme concentration, and phenolic structure also affect the inhibition of cellulose conversion. Lignin-blocking agents have little effect on the inhibition effect of soluble phenolics, indicating that the inhibition mechanism of phenolics to enzyme is likely different from insoluble lignin. The inhibition of soluble phenolics can hardly be entirely removed by increasing enzyme concentration or adding blocking proteins due to the dispersity and multiple binding sites of phenolics

  14. Paraquat inhibits progesterone synthesis in human placental mitochondria.

    Science.gov (United States)

    Milczarek, Ryszard; Sokołowska, Ewa; Rybakowska, Iwona; Kaletha, Krystian; Klimek, Jerzy

    2016-07-01

    Human placenta mitochondria produces huge amounts of progesterone necessary for maintaining the pregnancy. Lipid peroxidation in human placental mitochondria inhibits progesterone synthesis and that inhibition can be reversed by superoxide dismutase and other antioxidants. Paraquat (PQ) a highly toxic herbicide generates superoxide radical inside cells and induces lipid peroxidation. Hence, it is supposed to stimulate lipid peroxidation in human placental mitochondria and in consequence to inhibit a placental mitochondrial steroidogenesis. Placentas were obtained from normal pregnancies. All experiments were done using isolated human placental mitochondria. Mitochondrial lipid peroxidation was determined as tiobarbituric acid reactive substances (TBARS). A conversion of cholesterol to pregnenolone or pregnenolone to progesterone was measured using radiolabeled steroids and thin layer chromatography. PQ enhanced the iron-dependent lipid peroxidation as also PQ heightened the inhibitory action of this process on progesterone synthesis in isolated human placental mitochondria. Paradoxically, a superoxide dismutase (SOD) reversed the inhibition of progesterone synthesis only minimally although it strongly inhibited PQ stimulated iron-dependent lipid peroxidation. When iron was absent, PQ stimulated only negligible lipid peroxidation but strongly inhibited progesterone synthesis. SOD had no effect on inhibition of progesterone synthesis by PQ. PQ strongly inhibited of the conversion of cholesterol to pregnenolone but had not got any influence on the enzymatic activity of mitochondrial 3β-hydroxysteroid dehydrogenase. PQ strongly decreased the efficiency of NADPH-dependent cytochrome P450 reduction as well as it promoted the rapid oxidation of the pre-reduced mitochondrial cytochrome P450. However PQ has not inhibited combined activity of adrenodoxin reductase and adrenodoxin. We conclude that the most important reason of the inhibition of progesterone synthesis by PQ

  15. An alternative inhibition method for determining cross-reactive allergens.

    Science.gov (United States)

    Schmidt-Hieltjes, Yvonne; Teodorowicz, Malgorzata; Jansen, Ad; den Hartog, Gerco; Elfvering-Berendsen, Lisette; de Jong, Nicolette W; Savelkoul, Huub F J; Ruinemans-Koerts, Janneke

    2017-02-01

    Inhibition assays are an useful tool to identify the allergen of primary sensitization of cross-reactive allergens. Classical ELISA-based inhibition assays are limited by both the availability of commercial standardized allergen extracts and the experience and knowledge needed for making home-made extracts. Moreover the direct comparison of the inhibition ELISAs outcomes between different laboratories is difficult because of different sources of used allergen extracts and a number of methodological variations. Therefore, we propose a novel ImmunoCap (Phadia, Thermofisher Scientific) based immunoinhibition method with the use of commercially available Caps as the allergen source. The novel ImmunoCap based immunoinhibition method was developed and tested with sera from patients with a well-known cross-reactive sensitization for fig (Ficus carica) and ficus (Ficus benjamina). Results were compared with a classically applied inhibition method, i.e. addition of homemade allergen extract to patient serum. The amount of allergens (fig and ficus extracts) needed to reach a similar degree of inhibition was comparable for both inhibition methods. The ImmunoCap based inhibition assay, in addition to classical inhibition methods, is a valuable tool as the ImmunoCap analyzer and commercial allergens (Caps) are more widely available which makes the outcomes of inhibition tests comparable between different laboratories. Furthermore, in the ImmunoCap inhibition method the same protein source is used for both the inhibition of sIgE and sIgE measurement, which might be even more relevant when multiple cross-reactive allergens are tested.

  16. Inhibition of RAS in diabetic nephropathy

    Directory of Open Access Journals (Sweden)

    Yacoub R

    2015-04-01

    Full Text Available Rabi Yacoub, Kirk N Campbell Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, USA Abstract: Diabetic kidney disease (DKD is a progressive proteinuric renal disorder in patients with type 1 or type 2 diabetes mellitus. It is a common cause of end-stage kidney disease worldwide, particularly in developed countries. Therapeutic targeting of the renin–angiotensin system (RAS is the most validated clinical strategy for slowing disease progression. DKD is paradoxically a low systematic renin state with an increased intrarenal RAS activity implicated in its pathogenesis. Angiotensin II (AngII, the main peptide of RAS, is not only a vasoactive peptide but functions as a growth factor, activating interstitial fibroblasts and mesangial and tubular cells, while promoting the synthesis of extracellular matrix proteins. AngII also promotes podocyte injury through increased calcium influx and the generation of reactive oxygen species. Blockade of the RAS using either angiotensin converting enzyme inhibitors, or angiotensin receptor blockers can attenuate progressive glomerulosclerosis in animal models, and slows disease progression in humans with DKD. In this review, we summarize the role of intrarenal RAS activation in the pathogenesis and progression of DKD and the rationale for RAS inhibition in this population. Keywords: renin–angiotensin system, diabetic kidney disease, angiotensin II, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers

  17. Motor inhibition in hysterical conversion paralysis.

    Science.gov (United States)

    Cojan, Yann; Waber, Lakshmi; Carruzzo, Alain; Vuilleumier, Patrik

    2009-09-01

    Brain mechanisms underlying hysterical conversion symptoms are still poorly known. Recent hypotheses suggested that activation of motor pathways might be suppressed by inhibitory signals based on particular emotional situations. To assess motor and inhibitory brain circuits during conversion paralysis, we designed a go-nogo task while a patient underwent functional magnetic resonance imaging (fMRI). Preparatory activation arose in right motor cortex despite left paralysis, indicating preserved motor intentions, but with concomitant increases in vmPFC regions that normally mediate motivational and affective processing. Failure to execute movement on go trials with the affected left hand was associated with activations in precuneus and ventrolateral frontal gyrus. However, right frontal areas normally subserving inhibition were activated by nogo trials for the right (normal) hand, but not during go trials for the left hand (affected by conversion paralysis). By contrast, a group of healthy controls who were asked to feign paralysis showed similar activation on nogo trials and left-go trials with simulated weakness, suggesting that distinct inhibitory mechanisms are implicated in simulation and conversion paralysis. In the patient, right motor cortex also showed enhanced functional connectivity with the posterior cingulate cortex, precuneus, and vmPFC. These results suggest that conversion symptoms do not act through cognitive inhibitory circuits, but involve selective activations in midline brain regions associated with self-related representations and emotion regulation.

  18. Inhibition of carcinogenesis by retinoids. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Nettesheim, P.

    1979-01-01

    Progress made in recent years in the search for retinoids with anticarcinogenic activity is reviewed. There are many studies to be found in the literature which show no substantial effect of retinoids on carcinogenesis or tumor growth. Some of these negative findings may be related to the carcinogen dose used, the type of retinoid used, the dose, dose schedule or mode of administration of the retinoid. Others may indicate that the particular type of tumor or tumor system is, indeed, refractory to retinoids in general or to those retinoids that were tested. A great gap still exists in our knowledge concerning the pharmake-kinetics of most retinoids their availability to various normal and cancerous tissues, and the role and existence of transport and binding proteins. There are studies which indicate that under certain conditions, particularly conditions of topical application, some retinoids may even enhance carcinogenesis. It seems, however, indisputable by now that some retinoids are effective inhibitors of carcinogenesis in some organ systems and can even inhibit the growth of some established tumors. While the mechanisms of these inhibitory effects are presently not understood, it does seem clear that they are not mediated via the cytotoxic mechanisms typical of chemotherapeutic agents. The hope that retinoids might become an effective tool to halt the progression of some neoplastic diseases, seems to be justified.

  19. Inhibition of lignifying processes by sulfur dioxide

    International Nuclear Information System (INIS)

    Pfanz, H.; Oppmann, B.

    1991-01-01

    Intercellular washing fluids (IWF) from spruce needles (Picea abies L. Karst.) contain peroxidases 1-2% of total IWF protein. These apoplastic enzymes show the ability to polymerize monophenols or phenylpropanes to form lignin precursors in vitro. In the presence of potentially acidic air pollutants like NO 2 , HF(20 mM of salts in solution), and in the presence of Pb-, Cd- (0.5 mM) or Al-salts (8 mM) no inhibitory effect on the polymerization reactions examined was detectable. In contrast, the anions of SO 2 (sulfite and bisulfite) revealed a strong inhibition on the dimerization of ferulic and caffeic acid (Ki ca. 1 mM), and on the dehydration of syringaldazine (Ki ca. 8 μM). Polymerization of coniferyl alcohol, on the other hand, seemed to be enhanced. Maier-Maercker and Koch (1986) demonstrated that the cell walls of guard cells from undamaged spruce needles are properly lignified, whereas those of damaged needles seem to be affected. It is therefore assumed that cell wall lignification, and concomitantly stomatal regulation of coniferous needles are disturbed in regions with high atmospheric SO 2 pollution (e.g. Ore Mountains in CSFR)

  20. Hyper-accurate ribosomes inhibit growth.

    Science.gov (United States)

    Ruusala, T; Andersson, D; Ehrenberg, M; Kurland, C G

    1984-11-01

    We have compared both in vivo and in vitro translation by ribosomes from wild-type bacteria with those from streptomycin-resistant (SmR), streptomycin-dependent (SmD) and streptomycin-pseudo-dependent (SmP) mutants. The three mutant bacteria translate more accurately and more slowly in the absence of streptomycin (Sm) than do wild-type bacteria. In particular, the SmP bacteria grow at roughly half the rate of the wild-type in the absence of Sm. The antibiotic stimulates both the growth rate and the translation rate of SmP bacteria by approximately 2-fold, but it simultaneously increases the nonsense suppression rate quite dramatically. Kinetic experiments in vitro show that the greater accuracy and slower translation rates of mutant ribosomes compared with wild-type ribosomes are associated with much more rigorous proofreading activities of SmR, SmD and SmP ribosomes. Sm reduces the proofreading flows of the mutant ribosomes and stimulates their elongation rates. The data suggest that these excessively accurate ribosomes are kinetically less efficient than wild-type ribosomes, and that this inhibits mutant growth rates. The stimulation of the growth of the mutants by Sm results from the enhanced translational efficiency due to the loss of proofreading, which more than offsets the loss of accuracy caused by the antibiotic.

  1. Inhibition of Midkine Augments Osteoporotic Fracture Healing.

    Directory of Open Access Journals (Sweden)

    Melanie Haffner-Luntzer

    Full Text Available The heparin-binding growth and differentiation factor midkine (Mdk is proposed to negatively regulate osteoblast activity and bone formation in the adult skeleton. As Mdk-deficient mice were protected from ovariectomy (OVX-induced bone loss, this factor may also play a role in the pathogenesis of postmenopausal osteoporosis. We have previously demonstrated that Mdk negatively influences bone regeneration during fracture healing. Here, we investigated whether the inhibition of Mdk using an Mdk-antibody (Mdk-Ab improves compromised bone healing in osteoporotic OVX-mice. Using a standardized femur osteotomy model, we demonstrated that Mdk serum levels were significantly enhanced after fracture in both non-OVX and OVX-mice, however, the increase was considerably greater in osteoporotic mice. Systemic treatment with the Mdk-Ab significantly improved bone healing in osteoporotic mice by increasing bone formation in the fracture callus. On the molecular level, we demonstrated that the OVX-induced reduction of the osteoanabolic beta-catenin signaling in the bony callus was abolished by Mdk-Ab treatment. Furthermore, the injection of the Mdk-Ab increased trabecular bone mass in the skeleton of the osteoporotic mice. These results implicate that antagonizing Mdk may be useful for the therapy of osteoporosis and osteoporotic fracture-healing complications.

  2. Inhibition of cell proliferation by glycerol

    International Nuclear Information System (INIS)

    Wiebe, J.P.; Dinsdale, C.J.

    1991-01-01

    The effect of glycerol on proliferation of BHK, CHO, HBL, MCF-7, and human glioma cells was studied. Cell proliferation was significantly decreased in all the cell lines at glycerol concentrations of 2-4% in the culture medium. The inhibition was dose-dependent, complete suppression of proliferation occurring at a glycerol concentration of 4% for the MCF-7 cell line and 6-8% for the BHK, CHO and human glioma cells. Studies on [ 3 H]thymidine incorporation correlate with the effect on cell proliferation. The viability of the cells was not significantly affected until higher concentrations of glycerol were present. Recovery studies with BHK cells indicated that replacement of the glycerol medium with glycerol-free medium resulted in full recovery following exposure to 4% glycerol and only partial recovery of proliferation rate following exposure to 10-12% glycerol. It is concluded that glycerol, a substance that is normally present in tissues, can serve as a potent inhibitor of cell proliferation

  3. Lycopene Inhibits Propagation of Chlamydia Infection

    Directory of Open Access Journals (Sweden)

    Naylia A. Zigangirova

    2017-01-01

    Full Text Available Chlamydiaceae is a family of obligate intracellular pathogenic bacteria with similar developmental cycles and cell biology responsible for a wide range of diseases in different hosts including genital and eye inflammatory diseases, arthritis, and inflammatory diseases of the respiratory and cardiovascular systems. In the present paper, we report that lycopene, one of the main dietary carotenoids, which is present in tomato and some other fruits, has a strong inhibitory effect on C. trachomatis and C. pneumoniae infections in alveolar macrophages. This finding was documented by both immunofluorescence analysis and electron microscopy. It was noted that lycopene treatment inhibited intracellular phase of the chlamydial developmental cycle and resulted in a significant loss of infectious progeny. The antichlamydial effect of lycopene was also confirmed in a clinical setting. There was a significant reduction of IgG antibodies against C. pneumoniae in the serum of volunteers treated for a month with oral ingestion of 7 mg of lycopene. Additional studies are needed to further explore the antichlamydial activity of lycopene and its possible effect on C. pneumoniae in relation to antichlamydial activity of lycopene to mechanisms of atherosclerosis.

  4. Hydrogen peroxide inhibition of bicupin oxalate oxidase.

    Science.gov (United States)

    Goodwin, John M; Rana, Hassan; Ndungu, Joan; Chakrabarti, Gaurab; Moomaw, Ellen W

    2017-01-01

    Oxalate oxidase is a manganese containing enzyme that catalyzes the oxidation of oxalate to carbon dioxide in a reaction that is coupled with the reduction of oxygen to hydrogen peroxide. Oxalate oxidase from Ceriporiopsis subvermispora (CsOxOx) is the first fungal and bicupin enzyme identified that catalyzes this reaction. Potential applications of oxalate oxidase for use in pancreatic cancer treatment, to prevent scaling in paper pulping, and in biofuel cells have highlighted the need to understand the extent of the hydrogen peroxide inhibition of the CsOxOx catalyzed oxidation of oxalate. We apply a membrane inlet mass spectrometry (MIMS) assay to directly measure initial rates of carbon dioxide formation and oxygen consumption in the presence and absence of hydrogen peroxide. This work demonstrates that hydrogen peroxide is both a reversible noncompetitive inhibitor of the CsOxOx catalyzed oxidation of oxalate and an irreversible inactivator. The build-up of the turnover-generated hydrogen peroxide product leads to the inactivation of the enzyme. The introduction of catalase to reaction mixtures protects the enzyme from inactivation allowing reactions to proceed to completion. Circular dichroism spectra indicate that no changes in global protein structure take place in the presence of hydrogen peroxide. Additionally, we show that the CsOxOx catalyzed reaction with the three carbon substrate mesoxalate consumes oxygen which is in contrast to previous proposals that it catalyzed a non-oxidative decarboxylation with this substrate.

  5. Acetylcholinesterase-inhibiting Alkaloids from Zephyranthes concolor

    Directory of Open Access Journals (Sweden)

    Sebastien Arseneau

    2011-11-01

    Full Text Available The bulbs and aerial parts of Zephyranthes concolor (Lindl. Benth. & Hook. f. (Amaryllidaceae, an endemic species to Mexico, were found to contain the alkaloids chlidanthine, galanthamine, galanthamine N-oxide, lycorine, galwesine, and epinorgalanthamine. Since currently only partial and low resolution 1H-NMR data for chlidanthine acetate are available, and none for chlidanthine, its 1D and 2D high resolution 1H- and 13C-NMR spectra were recorded. Unambiguous assignations were achieved with HMBC, and HSQC experiments, and its structure was corroborated by X-ray diffraction. Minimum energy conformation for structures of chlidanthine, and its positional isomer galanthamine, were calculated by molecular modelling. Galanthamine is a well known acetylcholinesterase inhibitor; therefore, the isolated alkaloids were tested for this activity. Chlidanthine and galanthamine N-oxide inhibited electric eel acetylcholinesterase (2.4 and 2.6 × 10−5 M, respectively, indicating they are about five times less potent than galanthamine, while galwesine was inactive at 10−3 M. Inhibitory activity of HIV-1 replication, and cytotoxicity of the isolated alkaloids were evaluated in human MT-4 cells; however, the alkaloids showed poor activity as compared with standard anti-HIV drugs, but most of them were not cytotoxic.

  6. Insulin-Inducible SMILE Inhibits Hepatic Gluconeogenesis.

    Science.gov (United States)

    Lee, Ji-Min; Seo, Woo-Young; Han, Hye-Sook; Oh, Kyoung-Jin; Lee, Yong-Soo; Kim, Don-Kyu; Choi, Seri; Choi, Byeong Hun; Harris, Robert A; Lee, Chul-Ho; Koo, Seung-Hoi; Choi, Hueng-Sik

    2016-01-01

    The role of a glucagon/cAMP-dependent protein kinase-inducible coactivator PGC-1α signaling pathway is well characterized in hepatic gluconeogenesis. However, an opposing protein kinase B (PKB)/Akt-inducible corepressor signaling pathway is unknown. A previous report has demonstrated that small heterodimer partner-interacting leucine zipper protein (SMILE) regulates the nuclear receptors and transcriptional factors that control hepatic gluconeogenesis. Here, we show that hepatic SMILE expression was induced by feeding in normal mice but not in db/db and high-fat diet (HFD)-fed mice. Interestingly, SMILE expression was induced by insulin in mouse primary hepatocyte and liver. Hepatic SMILE expression was not altered by refeeding in liver-specific insulin receptor knockout (LIRKO) or PKB β-deficient (PKBβ(-/-)) mice. At the molecular level, SMILE inhibited hepatocyte nuclear factor 4-mediated transcriptional activity via direct competition with PGC-1α. Moreover, ablation of SMILE augmented gluconeogenesis and increased blood glucose levels in mice. Conversely, overexpression of SMILE reduced hepatic gluconeogenic gene expression and ameliorated hyperglycemia and glucose intolerance in db/db and HFD-fed mice. Therefore, SMILE is an insulin-inducible corepressor that suppresses hepatic gluconeogenesis. Small molecules that enhance SMILE expression would have potential for treating hyperglycemia in diabetes. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  7. Clinical features of latent inhibition in schizophrenia.

    Science.gov (United States)

    Rascle, C; Mazas, O; Vaiva, G; Tournant, M; Raybois, O; Goudemand, M; Thomas, P

    2001-09-01

    Paradigms of Latent Inhibition (LI) are inter-species and derived from learning theories. They are considered as tools which allow the attentional processes to be studied. The absence of LI is interpreted as difficulty in discriminating relevant and irrelevant stimuli. Abolition of LI has been shown in acute schizophrenics. The objectives of our study were partly to validate an LI paradigm, based on a contingency detection between two stimuli, in healthy subjects, and partly to analyse LI in schizophrenics. The study included 105 subjects (65 patients and 40 controls). Patients fulfilled the DSM IV diagnosis of schizophrenia. 35 in the acute phase and 30 in the chronic phase. We observed a loss of LI for acute schizophrenics, and an enhancement of LI for chronic schizophrenics. The variations in LI are interpreted from the perspective of a disturbance in the attentional processes. The LI status in acute schizophrenics appears to correlate with the clinical criteria with a prognostic value (low intensity of the negative dimension, late age at the first hospitalization). Moreover, the enhancement of LI correlates with the negative dimension of schizophrenic disease. This correlation is found in acute and chronic schizophrenics. It suggests that the variations of LI may be an indicator of adaptive strategies to a cognitive dysfunction specific to schizophrenia.

  8. Linking algal growth inhibition to chemical activity

    DEFF Research Database (Denmark)

    Schmidt, Stine N.; Mayer, Philipp

    Unitless chemical activity, expressing the energetic level of a compound relative to its energetic level in pure liquid [0-1], has proven useful to quantify the effective exposure to hydrophobic organic compounds through both aerial and aqueous media. Several studies have linked toxicity to chemi......Unitless chemical activity, expressing the energetic level of a compound relative to its energetic level in pure liquid [0-1], has proven useful to quantify the effective exposure to hydrophobic organic compounds through both aerial and aqueous media. Several studies have linked toxicity...... to chemical activity, as opposed to e.g. the total concentration. Baseline toxicity (narcosis) for neutral hydrophobic organic compounds has been shown to initiate in the narrow chemical activity range of 0.01 to 0.1. This presentation focuses on linking algal growth inhibition to chemical activity...... with the aims to (1) further challenge the current chemical activity range for baseline toxicity, and (2) extend the utilisation of the chemical activity concept across compounds and species. The first part of the presentation focuses on results from a recently published study, in which toxicity data for 39 non...

  9. Celecoxib inhibits osteoblast differentiation independent of cyclooxygenase activity.

    Science.gov (United States)

    Matsuyama, Atsushi; Higashi, Sen; Tanizaki, Saori; Morotomi, Takahiko; Washio, Ayako; Ohsumi, Tomoko; Kitamura, Chiaki; Takeuchi, Hiroshi

    2018-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) exert their effects primarily by inhibiting the activity of cyclooxygenase (COX), thus suppressing prostaglandin synthesis. Some NSAIDs are known to perform functions other than pain control, such as suppressing tumour cell growth, independent of their COX-inhibiting activity. To identify NSAIDs with COX-independent activity, we examined various NSAIDs for their ability to inhibit osteoblastic differentiation using the mouse pre-osteoblast cell line MC3T3-E1. Only celecoxib and valdecoxib strongly inhibited osteoblastic differentiation, and this effect was not correlated with COX-inhibiting activity. Moreover, 2,5-dimethyl (DM)-celecoxib, a celecoxib analogue that does not inhibit COX activity, also inhibited osteoblastic differentiation. Celecoxib and DM-celecoxib inhibited osteoblastic differentiation induced by bone morphogenetic protein (BMP)-2 in C2C12 mouse myoblast cell line. Although celecoxib suppresses the growth of some tumour cells, the viability and proliferation of MC3T3-E1 cells were not affected by celecoxib or DM-celecoxib. Instead, celecoxib and DM-celecoxib suppressed BMP-2-induced phosphorylation of Smad1/5, a major downstream target of BMP receptor. Although it is well known that COX plays important roles in osteoblastic differentiation, these results suggest that some NSAIDs, such as celecoxib, have targets other than COX and regulate phospho-dependent intracellular signalling, thereby modifying bone remodelling. © 2017 John Wiley & Sons Australia, Ltd.

  10. Comparative study of the inhibition effects of alkaloid and non ...

    African Journals Online (AJOL)

    The Alkaloid and Non- alkaloid fractions of the ethanolic extracts from Costus afer (AECA and NAECA) were comparatively studied for their inhibitive properties on the corrosion of mild steel in 5 M HCl solution using Gravimetric and Gasometric techniques. The results revealed that both extracts inhibited the corrosion of ...

  11. Experimental and quantum chemical studies on corrosion inhibition ...

    Indian Academy of Sciences (India)

    The corrosion inhibition effect of fluconazole (FLU) was investigated on steel in 1 M hydrochloric acid solution. Weight loss measurements and atomic force microscope analysis were utilized to investigate the corrosion inhibition properties and film formation behaviour of FLU. Quantum chemical approach was also used to ...

  12. INHIBITION OF THE CORROSION OF MILD STEEL IN ...

    African Journals Online (AJOL)

    ABSTRACT. The inhibition of corrosion of mild steel in hydrochloric acid by isatin glycine (ING) and isatin (IN) at 30-60 oC and concentrations of 0.0001 M to 0.0005 M was studied via weight loss method. At the highest inhibitor concentration studied ING exhibited inhibition efficiency of 87% while IN exhibited 84% at 60 oC.

  13. Overcoming heat shock protein inhibition at critical temperature vital ...

    African Journals Online (AJOL)

    Our results show that the inhibition process is a functional variance of time and genetic variability characterized by differential down-regulation of housekeeping proteins (HKPs) of about 55.7 and 43.5 KD in some cultivars and complete inhibition of a prominent 19.9 KD HKP in Kufri Jyoti at all stressed time. Furthermore, the ...

  14. Methanol Extract of Hydroclathrus clathratus Inhibits Production of ...

    African Journals Online (AJOL)

    Methanol Extract of Hydroclathrus clathratus Inhibits Production of Nitric Oxide, Prostaglandin E2 and Tumor Necrosis Factor-α in Lipopolysaccharidestimulated BV2 Microglial Cells via Inhibition of NF-κB Activity. RGPT Jayasooriya, D-O Moon, YH Chol, C-H Yoon, G-Y Kim ...

  15. Trichilia monadelpha Bark Extracts Inhibit Carrageenan-Induced ...

    African Journals Online (AJOL)

    The present study was undertaken to evaluate the anti-inflammatory properties of aqueous (TWE), alcoholic (TAE) and petroleum ether extract (TPEE) of T. ... The reference anti-inflammatory drugs (diclofenac and dexamethasone) inhibited the chick-carrageenan-induced footpad oedema, with maximal inhibitions of ...

  16. Stuttering Inhibition via Altered Auditory Feedback during Scripted Telephone Conversations

    Science.gov (United States)

    Hudock, Daniel; Kalinowski, Joseph

    2014-01-01

    Background: Overt stuttering is inhibited by approximately 80% when people who stutter read aloud as they hear an altered form of their speech feedback to them. However, levels of stuttering inhibition vary from 60% to 100% depending on speaking situation and signal presentation. For example, binaural presentations of delayed auditory feedback…

  17. synthesis, DNA interaction and comparison of lipase inhibition propert

    Indian Academy of Sciences (India)

    GÜNAY KAYA KANTAR

    Abstract. Novel eugenol-substituted zinc(II) azaphthalocyanines (ZnAzaPcs) were synthesised and their lipase inhibition and DNA binding properties compared with phthalocyanines (Pcs) containing eugenol. This is the first study on lipase inhibition and DNA binding of Pcs and AzaPcs containing a pharmacophore group, ...

  18. Cohort-Sequential Study of Conflict Inhibition during Middle Childhood

    Science.gov (United States)

    Rollins, Leslie; Riggins, Tracy

    2017-01-01

    This longitudinal study examined developmental changes in conflict inhibition and error correction in three cohorts of children (5, 7, and 9 years of age). At each point of assessment, children completed three levels of Luria's tapping task (1980), which requires the inhibition of a dominant response and maintenance of task rules in working…

  19. Inhibition of Snl6 expression for biofuel production

    Energy Technology Data Exchange (ETDEWEB)

    Bart, Rebecca; Chern, Mawsheng; Ronald, Pamela; Vega-Sanchez, Miguel

    2018-04-03

    The invention provides compositions and methods for inhibiting the expression of the gene Snl6 in plants. Plants with inhibited expression of Snl6 have use in biofuel production, e.g., by increasing the amount of soluble sugar that can be extracted from the plant.

  20. Social inhibition sense of belonging and vulnerability to internalizing problems

    NARCIS (Netherlands)

    de Moor, E.L.; Denollet, J.; Laceulle, O.M.

    2018-01-01

    Background The aim of this study was to provide a conceptual test of how social inhibition, sense of belonging and internalizing problems are related, and whether sense of belonging moderates or mediates the relation between social inhibition and internalizing problems. Methods Data were used from

  1. Menadione inhibits MIBG uptake in two neuroendocrine cell lines

    NARCIS (Netherlands)

    Cornelissen, J.; Tytgat, G. A.; van den Brug, M.; van Kuilenburg, A. B.; Voûte, P. A.; van Gennip, A. H.

    1997-01-01

    In this paper we report on our studies of the effect of menadione on the uptake of MIBG in the neuroendocrine cell lines PC12 and SK-N-SH. Menadione inhibits the uptake of MIBG in both cell lines in a dose-dependent manner. Inhibition of MIBG uptake is most pronounced in the PC12 cell line.

  2. An alternative inhibition method for determining cross-reactive allergens

    NARCIS (Netherlands)

    Schmidt-Hieltjes, Yvonne; Teodorowicz, Gosia; Jansen, Ad; Hartog, Den Gerco; Elfvering-Berendsen, Lisette; Jong, De Nicolette W.; Savelkoul, Huub F.J.; Ruinemans-Koerts, Janneke

    2017-01-01

    Inhibition assays are an useful tool to identify the allergen of primary sensitization of cross-reactive allergens. Classical ELISA-based inhibition assays are limited by both the availability of commercial standardized allergen extracts and the experience and knowledge needed for making home-made

  3. Attention Inhibition Training Can Reduce Betel-Nut Chewing Time

    Directory of Open Access Journals (Sweden)

    Ming-Chou Ho

    2011-05-01

    Full Text Available Betel nut (or areca is the fourth most commonly used drug worldwide after tobacco, alcohol, and caffeine. Many chemical ingredients of betel nut are carcinogenic. We examined whether the manipulation of attentional inhibition toward the areca-related stimuli could affect betel-nut chewing time. Three matched groups of habitual chewers were recruited: inhibit-areca, inhibit-non-areca, and control. This study consisted of a Go/No-Go task for inhibition training, followed by a taste test for observing chewing behavior. The Go/No-Go task constituted three phases (pretest, training and posttest. In the taste test, the habitual chewers were asked to rate the flavors of one betel nut and one gum. The purpose (blind to the chewers of this taste test was to observe whether their picking order and chewing time were affected by experimental manipulation. Results from the Go/No-Go task showed successful training. Further, the training groups (the inhibit-areca and inhibit-non-areca groups showed a significant reduction in betel nut chewing time, in comparison to the control group. Since both training groups showed reduced chewing time, the inhibition training may affect general control ability, in regardless of the stimulus (areca or not to be inhibited. Reduced chewing time is important for reducing areca-related diseases.

  4. Distractor Inhibition: Principles of Operation during Selective Attention

    Science.gov (United States)

    Wyatt, Natalie; Machado, Liana

    2013-01-01

    Research suggests that although target amplification acts as the main determinant of the efficacy of selective attention, distractor inhibition contributes under some circumstances. Here we aimed to gain insight into the operating principles that regulate the use of distractor inhibition during selective attention. The results suggest that, in…

  5. Probe substrate and enzyme source-dependent inhibition of UDP ...

    African Journals Online (AJOL)

    Background: Drug-metabolizing enzymes (DMEs) inhibition based drug-drug interaction and herb-drug interaction severely challenge the R&D process of drugs or herbal ingredients. Objective: To evaluate the inhibition potential of wogonin (an important flavonoid isolated from the root of Scutellaria baicalensis) towards ...

  6. Study of electroplated silver-palladium biofouling inhibiting coating

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Hilbert, Lisbeth Rischel; Schroll, Casper

    2008-01-01

    Biofouling can cause many undesirable effects in industrial and medical settings. In this study, a new biofouling inhibiting Ag-Pd surface was designed to form an inhibiting effect by itself. This design was based on silver combined with nobler palladium, both with catalytic properties. Owing to ...

  7. Peliminary examination of herbal extracts on the inhibition of ...

    African Journals Online (AJOL)

    Methods: The activity was quantitatively assessed on the basis of the inhibition zone, and their activity index was also calculated along with the MIC method. Results: All the plants demonstrated antimicrobial activity against H. pylori with zone of inhibition diameters ranging from 0 - 30 mm and minimum inhibitory ...

  8. Experimental and quantum chemical studies on corrosion inhibition ...

    Indian Academy of Sciences (India)

    Abstract. The corrosion inhibition effect of fluconazole (FLU) was investigated on steel in 1 M hydrochloric acid solution. Weight loss measurements and atomic force microscope analysis were utilized to investigate the corrosion inhibition properties and film formation behaviour of FLU. Quantum chemical approach was also ...

  9. Experimental and quantum chemical studies on corrosion inhibition

    Indian Academy of Sciences (India)

    The corrosion inhibition effect of fluconazole (FLU) was investigated on steel in 1 M hydrochloric acid solution. Weight loss measurements and atomic force microscope analysis were utilized to investigate the corrosion inhibition properties and film formation behaviour of FLU. Quantum chemical approach was also used to ...

  10. Inhibition of autophagy initiation potentiates chemosensitivity in mesothelioma.

    Science.gov (United States)

    Follo, Carlo; Cheng, Yao; Richards, William G; Bueno, Raphael; Broaddus, Virginia Courtney

    2018-03-01

    The benefits of inhibiting autophagy in cancer are still controversial, with differences in outcome based on the type of tumor, the context and the particular stage of inhibition. Here, we investigated the impact of inhibiting autophagy at different stages on chemosensitivity using 3-dimensional (3D) models of mesothelioma, including ex vivo human tumor fragment spheroids. As shown by LC3B accumulation, we successfully inhibited autophagy using either an early stage ULK1/2 inhibitor (MRT 68921) or a late stage inhibitor (hydroxychloroquine). We found that inhibition of autophagy at the early stage, but not at late stage, potentiated chemosensitivity. This effect was seen only in those spheroids with high autophagy and active initiation at steady state. Inhibition of autophagy alone, at either early or late stage, did not cause cell death, showing that the inhibitors were non-toxic and that mesothelioma did not depend on autophagy at baseline, at least over 24 h. Using ATG13 puncta analysis, we found that autophagy initiation identified tumors that are more chemosensitive at baseline and after autophagy inhibition. Our results highlight a potential role of autophagy initiation in supporting mesothelioma cells during chemotherapy. Our work also highlights the importance of testing the inhibition of different stages in order to uncover the role of autophagy and the potential of its modulation in the treatment of cancer. © 2017 Wiley Periodicals, Inc.

  11. Sulindac Sulfide, but Not Sulindac Sulfone, Inhibits Colorectal Cancer Growth

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    Christopher S. Williams

    1999-06-01

    Full Text Available Sulindac sulfide, a metabolite of the nonsteroidal antiinflammatory drug (NSAID sulindac sulfoxide, is effective at reducing tumor burden in both familial adenomatous polyposis patients and in animals with colorectal cancer. Another sulindac sulfoxide metabolite, sulindac sulfone, has been reported to have antitumor properties without inhibiting cyclooxygenase activity. Here we report the effect of sulindac sulfone treatment on the growth of colorectal carcinoma cells. We observed that sulindac sulfide or sulfone treatment of HCA-7 cells led to inhibition of prostaglandin E2 production. Both sulindac sulfide and sulfone inhibited HCA-7 and HCT-116 cell growth in vitro. Sulindac sulfone had no effect on the growth of either HCA-7 or HCT-116 xenografts, whereas the sulfide derivative inhibited HCA-7 growth in vivo. Both sulindac sulfide and sulfone inhibited colon carcinoma cell growth and prostaglandin production in vitro, but sulindac sulfone had no effect on the growth of colon cancer cell xenografts in nude mice.

  12. Associative learning phenomena in the snail (Helix aspersa): conditioned inhibition.

    Science.gov (United States)

    Acebes, Félix; Solar, Patricia; Moris, Joaquín; Loy, Ignacio

    2012-03-01

    Two experiments using garden snails (Helix aspersa) showed conditioned inhibition using both retardation and summation tests. Conditioned inhibition is a procedure by which a stimulus becomes a predictor of the absence of a relevant event--the unconditioned stimulus (US). Typically, conditioned inhibition consists of pairings between an initially neutral conditioned stimulus, CS(2), and an effective excitatory conditioned stimulus, CS(1), in the absence of the US. Retardation and summation tests are required in order to confirm that CS(2) has acquired inhibitory properties. Conditioned inhibition has previously been found in invertebrates; however, these demonstrations did not use the retardation and summation tests required for an unambiguous demonstration of inhibition, allowing for alternative explanations. The implications of our results for the fields of comparative cognition and invertebrate physiological models of learning are discussed.

  13. . Psychological predictors of inhibition development in educational environments

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    Symanyuk, Elvira E.

    2016-09-01

    Full Text Available This article examines psychological predictors of inhibition in educational environments as well as various aspects of pedagogical communication, including facilitation, which is aimed at enhancing educational effectiveness and developing students by means of using a particular communication style and the teacher’s personality. The need to study inhibition (the deterioration of teacher-children interactions; the negation of a student’s individuality; the inability to understand and accept students’ viewpoints; teacher-provoked conflicts; and emotional callousness is substantiated. The essence of psychological predictors as independent variables, changes in which lead to changes in other dependent variables, allowing the prediction of inhibition development, is explained. The research objective was to identify psychological predictors of the development of inhibition in pedagogical communication. An empirical study was conducted using standardized techniques for diagnosing communicative attitudes (V. Boyko, developing general communicative tolerance (V. Boyko, identifying aggressiveness (A. Asinger, identifying the level of empathy (V. Boyko, and identifying the degree of pedagogical inhibition (L. Polosova. The sample contained 375 teachers from Yekaterinburg educational institutions, with participant selection made using stratified sampling. The teacher’s personality features (a negative communicative attitude, low communicative tolerance and empathy, and higher levels of aggression were shown to be key predictors of inhibition, which itself was found to depend on the length of teaching experience. At the beginning of one’s professional teaching career, the level of inhibition is minimal. However, the level of inhibition reaches its maximum level after 5-10 years of teaching, and after 20 years, there is a sharp decrease in the level of inhibition. The conclusion of this study stresses the importance of developing strategies to

  14. Inhibition of Suicidal Erythrocyte Death by Reversine

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    Mohamed Jemaà

    2017-04-01

    Full Text Available Background/Aims: The A3 adenosine receptor antagonist reversine (2-(4-morpholinoanilino-6-cyclohexylaminopurine influences cellular differentiation, inhibits cell proliferation, induces cell-cycle arrest, triggers apoptosis, causes cell swelling with polyploidy and stimulates autophagy. The effect on apoptosis involves mitochondria and caspases. Erythrocytes are lacking mitochondria but express caspases and are, similar to apoptosis of nucleated cells, able to enter suicidal erythrocyte death or eryptosis. Stimulators of eryptosis include increase of cytosolic Ca2+ activity ([Ca2+]i, energy depletion and oxidative stress. The present study explored, whether reversine influences eryptosis. Methods: Flow cytometry was employed to quantify phosphatidylserine exposure at the cell surface from annexin-V-binding and cell volume from forward scatter. Measurements were made without or with energy depletion (glucose deprivation for 48 hours, Ca2+ loading (30 minutes treatment with 1 µM Ca2+ ionophore ionomycin, or oxidative stress (15 min exposure to 0.3 mM tert-butylhydroperoxide. Results: A 48 hours exposure of human erythrocytes to reversine (1-10 µM did not significantly modify the percentage of annexin-V-binding cells and forward scatter. Energy depletion, Ca2+ loading, and oxidative stress were each followed by profound and significant increase of the percentage annexin-V-binding erythrocytes and a significant decrease of forward scatter. The effects of each, Ca2+ loading, energy depletion and oxidative stress on annexin-V-binding were significantly blunted in the presence of reversine (1-10 µM. The effect of ionomycin, but not the effects of energy depletion and oxidative stress on forward scatter were again significantly blunted in the presence of reversine (≥1 µM]. Conclusions: Reversine is a powerful inhibitor of cell membrane scrambling following energy depletion, Ca2+ loading and oxidative stress.

  15. Volatile hydrocarbons inhibit methanogenic crude oil degradation

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    Angela eSherry

    2014-04-01

    Full Text Available Methanogenic degradation of crude oil in subsurface sediments occurs slowly, but without the need for exogenous electron acceptors, is sustained for long periods and has enormous economic and environmental consequences. Here we show that volatile hydrocarbons are inhibitory to methanogenic oil biodegradation by comparing degradation of an artificially weathered crude oil with volatile hydrocarbons removed, with the same oil that was not weathered. Volatile hydrocarbons (nC5-nC10, methylcyclohexane, benzene, toluene and xylenes were quantified in the headspace of microcosms. Aliphatic (n-alkanes nC12-nC34 and aromatic hydrocarbons (4-methylbiphenyl, 3-methylbiphenyl, 2-methylnaphthalene, 1-methylnaphthalene were quantified in the total hydrocarbon fraction extracted from the microcosms. 16S rRNA genes from key microorganisms known to play an important role in methanogenic alkane degradation (Smithella and Methanomicrobiales were quantified by quantitative PCR. Methane production from degradation of weathered oil in microcosms was rapid (1.1 ± 0.1 µmol CH4/g sediment/day with stoichiometric yields consistent with degradation of heavier n-alkanes (nC12-nC34. For non-weathered oil, degradation rates in microcosms were significantly lower (0.4 ± 0.3 µmol CH4/g sediment/day. This indicated that volatile hydrocarbons present in the non-weathered oil inhibit, but do not completely halt, methanogenic alkane biodegradation. These findings are significant with respect to rates of biodegradation of crude oils with abundant volatile hydrocarbons in anoxic, sulphate-depleted subsurface environments, such as contaminated marine sediments which have been entrained below the sulfate-reduction zone, as well as crude oil biodegradation in petroleum reservoirs and contaminated aquifers.

  16. Inhibition of Uterine Contractility by Thalidomide Analogs via Phosphodiesterase-4 Inhibition and Calcium Entry Blockade

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    Eduardo Fernández-Martínez

    2016-10-01

    Full Text Available Uterine relaxation is crucial during preterm labor. Phosphodiesterase-4 (PDE-4 inhibitors have been proposed as tocolytics. Some thalidomide analogs are PDE-4 inhibitors. The aim of this study was to assess the uterus-relaxant properties of two thalidomide analogs, methyl 3-(4-nitrophthalimido-3-(3,4-dimethoxyphenyl-propanoate (4NO2PDPMe and methyl 3-(4-aminophthalimido-3-(3,4-dimethoxyphenyl-propanoate (4APDPMe and were compared to rolipram in functional studies of spontaneous phasic, K+-induced tonic, and Ca2+-induced contractions in isolated pregnant human myometrial tissues. The accumulation of cAMP was quantified in HeLa cells. The presence of PDE-4B2 and phosphorylated myosin light-chain (pMLC, in addition to the effect of thalidomide analogs on oxytocin-induced pMLC, were assessed in human uterine myometrial cells (UtSMCs. Thalidomide analogs had concentration-dependent inhibitory effects on spontaneous and tonic contractions and inhibited Ca2+-induced responses. Tonic contraction was equipotently inhibited by 4APDPMe and rolipram (IC50 = 125 ± 13.72 and 98.45 ± 8.86 µM, respectively. Rolipram and the thalidomide analogs inhibited spontaneous and tonic contractions equieffectively. Both analogs increased cAMP accumulation in a concentration-dependent manner (p < 0.05 and induced changes in the subcellular localization of oxytocin-induced pMLC in UtSMCs. The inhibitory effects of thalidomide analogs on the contractions of pregnant human myometrium tissue may be due to their PDE-4 inhibitory effect and novel mechanism as calcium-channel blockers.

  17. The somatotopy of tic inhibition: Where and how much?

    Science.gov (United States)

    Ganos, Christos; Bongert, Jens; Asmuss, Luisa; Martino, Davide; Haggard, Patrick; Münchau, Alexander

    2015-08-01

    Tics are the hallmark feature of Tourette syndrome. The basic phenomenological and neurophysiological characteristics of tics have been widely investigated. Interestingly, the spatial distribution of tics across different body parts has received little attention. No previous study has investigated whether the capacity for voluntary tic inhibition also varies across body parts. We analyzed video sequences of 26 adolescents with Tourette syndrome in a "tic freely" condition, and in a "voluntary tic inhibition" condition, to obtain absolute tic counts for different body parts. Two measures of the spatial distribution of tics were then analyzed. Linear regression analyses were employed to investigate the relation between the contribution of each body part to overall tic behavior and the ability to inhibit tics in that body part, averaged over our patient group. Tic distribution across patients showed a characteristic somatotopic pattern, with the face most strongly represented. A significant negative relation was found between the ability to inhibit tics and pooled tic frequency across body parts. The body parts that exhibited the fewest tics were the ones for which tic inhibition was most effective. Our data are consistent with the idea that tic recruitment order reflects a "tic generator" spreading across a somatotopic map in the brain. Voluntary tic inhibition did not simply cause a proportional reduction of tics in each body part. Rather, the least affected body parts showed most effective voluntary tic inhibition. The results are discussed in terms of signal and noise within cortical-subcortical motor loops. © 2015 International Parkinson and Movement Disorder Society.

  18. Methylene Blue Inhibits Caspases by Oxidation of the Catalytic Cysteine.

    Science.gov (United States)

    Pakavathkumar, Prateep; Sharma, Gyanesh; Kaushal, Vikas; Foveau, Bénédicte; LeBlanc, Andrea C

    2015-09-24

    Methylene blue, currently in phase 3 clinical trials against Alzheimer Disease, disaggregates the Tau protein of neurofibrillary tangles by oxidizing specific cysteine residues. Here, we investigated if methylene blue can inhibit caspases via the oxidation of their active site cysteine. Methylene blue, and derivatives, azure A and azure B competitively inhibited recombinant Caspase-6 (Casp6), and inhibited Casp6 activity in transfected human colon carcinoma cells and in serum-deprived primary human neuron cultures. Methylene blue also inhibited recombinant Casp1 and Casp3. Furthermore, methylene blue inhibited Casp3 activity in an acute mouse model of liver toxicity. Mass spectrometry confirmed methylene blue and azure B oxidation of the catalytic Cys163 cysteine of Casp6. Together, these results show a novel inhibitory mechanism of caspases via sulfenation of the active site cysteine. These results indicate that methylene blue or its derivatives could (1) have an additional effect against Alzheimer Disease by inhibiting brain caspase activity, (2) be used as a drug to prevent caspase activation in other conditions, and (3) predispose chronically treated individuals to cancer via the inhibition of caspases.

  19. The development of children's inhibition: does parenting matter?

    Science.gov (United States)

    Roskam, Isabelle; Stievenart, Marie; Meunier, Jean-Christophe; Noël, Marie-Pascale

    2014-06-01

    Whereas a large body of research has investigated the maturation of inhibition in relation to the prefrontal cortex, far less research has been devoted to environmental factors that could contribute to inhibition improvement. The aim of the current study was to test whether and to what extent parenting matters for inhibition development from 2 to 8years of age. Data were collected from 421 families, with 348 mother-child dyads and 342 father-child dyads participating. Children's inhibition capacities and parenting behaviors were assessed in a three-wave longitudinal data collection. The main analyses examined the impact of parenting on the development of children's inhibition capacities. They were conducted using a multilevel modeling (MLM) framework. The results lead to the conclusion that both mothers and fathers contribute through their child-rearing behavior to their children's executive functioning, even when controlling for age-related improvement (maturation) and important covariates such as gender, verbal IQ, and place of enrollment. More significant relations between children's inhibition development and parenting were displayed for mothers than for fathers. More precisely, parenting behaviors that involve higher monitoring, lower discipline, inconsistency and negative controlling, and a positive parenting style are associated with good development of inhibition capacities in children. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Neural correlates of central inhibition during physical fatigue.

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    Masaaki Tanaka

    Full Text Available Central inhibition plays a pivotal role in determining physical performance during physical fatigue. Classical conditioning of central inhibition is believed to be associated with the pathophysiology of chronic fatigue. We tried to determine whether classical conditioning of central inhibition can really occur and to clarify the neural mechanisms of central inhibition related to classical conditioning during physical fatigue using magnetoencephalography (MEG. Eight right-handed volunteers participated in this study. We used metronome sounds as conditioned stimuli and maximum handgrip trials as unconditioned stimuli to cause central inhibition. Participants underwent MEG recording during imagery of maximum grips of the right hand guided by metronome sounds for 10 min. Thereafter, fatigue-inducing maximum handgrip trials were performed for 10 min; the metronome sounds were started 5 min after the beginning of the handgrip trials. The next day, neural activities during imagery of maximum grips of the right hand guided by metronome sounds were measured for 10 min. Levels of fatigue sensation and sympathetic nerve activity on the second day were significantly higher relative to those of the first day. Equivalent current dipoles (ECDs in the posterior cingulated cortex (PCC, with latencies of approximately 460 ms, were observed in all the participants on the second day, although ECDs were not identified in any of the participants on the first day. We demonstrated that classical conditioning of central inhibition can occur and that the PCC is involved in the neural substrates of central inhibition related to classical conditioning during physical fatigue.

  1. Australine, a pyrrolizidine alkaloid that inhibits amyloglucosidase and glycoprotein processing

    Energy Technology Data Exchange (ETDEWEB)

    Tropea, J.E.; Molyneux, R.J.; Kaushal, G.P.; Pan, Y.T.; Mitchell, M.; Elbein, A.D. (Univ. of Texas Health Science Center, San Antonio (USA))

    1989-03-07

    Australine is a polyhydroxylated pyrrolizidine alkaloid that was isolated from the seeds of the Australian tree Castanospermum australe and characterized by NMR and X-ray diffraction analysis. Since swainsonine and catanospermine are polyhydroxylated indolizidine alkaloids that inhibit specific glycosidases, the authors tested australine against a variety of exoglycosidases to determine whether it would inhibit any of these enzymes. This alkaloid proved to be a good inhibitor of the {alpha}-glucosidase amyloglucosidase (50% inhibition at 5.8 {mu}M), but it did not inhibit {beta}-glucosidase, {alpha}- or {beta}-mannosidase, or {alpha}- or {beta}-galactosidase. The inhibition of amyloglucosidase was of a competitive nature. Australine also inhibited the glycoprotein processing enzyme glucosidase I, but had only slight activity toward glucosidase II. When incubated with cultured cells, this alkaloid inhibited glycoprotein processing at the glucosidase I step and caused the accumulation of glycoproteins with Glc{sub 3}Man{sub 7-9}(GlcNAc){sub 2}-oligosaccharides.

  2. Inhibition of human neutrophil elastase by pentacyclic triterpenes.

    Directory of Open Access Journals (Sweden)

    Li Feng

    Full Text Available Inhibiting human neutrophil elastase (HNE is a promising strategy for treating inflammatory lung diseases, such as H1N1 and SARS virus infections. The use of sivelestat, the only clinically registered synthesized HNE inhibitor, is largely limited by its risk of organ toxicity because it irreversibly inhibits HNE. Therefore, potent reversible HNE inhibitors are promising alternatives to sivelestat.An in vitro HNE inhibition assay was employed to screen a series of triterpenes. Six pentacyclic triterpenes, but not tetracyclic triterpenes, significantly inhibited HNE. Of these pentacyclic triterpenes, ursolic acid exhibited the highest inhibitory potency (IC50 = 5.51 µM. The HNE inhibitory activity of ursolic acid was further verified using a mouse model of acute smoke-induced lung inflammation. The results of nuclear magnetic resonance and HNE inhibition kinetic analysis showed that the pentacyclic triterpenes competitively and reversibly inhibited HNE. Molecular docking experiments indicated that the molecular scaffold, 28-COOH, and a double bond at an appropriate location in the pentacyclic triterpenes are important for their inhibitory activity.Our results provide insights into the effects of pentacyclic triterpenes on lung inflammatory actions through reversible inhibition of HNE activity.

  3. Andrographolide inhibits multiple myeloma cells by inhibiting the TLR4/NF-κB signaling pathway.

    Science.gov (United States)

    Gao, Hui; Wang, Jianrong

    2016-02-01

    Andrographolide is an active component from the extract of Andrographis paniculata [(Burm.f) Nees], a medicinal plant from the Acanthaceae family. Pharmacological studies have revealed that andrographolide possesses anti-bacterial, anti-inflammatory, anti-viral, immune regulatory and hepatoprotective properties, and is efficacious in the treatment of cardiovascular diseases, while exhibiting low toxicity and low cost. The present study aimed to determine the inhibitory effects of andrographolide on the growth of multiple myeloma (MM) cells and its possible impact on the Toll-like receptor (TLR)4/nuclear factor (NF)-κB signaling pathway. Cell proliferation was detected using an MTT assay, cellular apoptosis was measured using flow cytometry, and caspase-9/3 activation were assessed using colorimetric assay kits. Furthermore, TLR4 and NF-κB protein expression was determined by western blot analysis. The results revealed that andrographolide reduced the proliferation, while increasing cellular apoptosis and caspase-9/3 activation of MM cells, in addition to downregulating the expression of TLR4 and NF-κB protein. Of note, TLR4- or NF-κB-targeting small-interfering (si)RNA enhanced the andrographolide-induced inhibition of cell proliferation and induction of apoptosis of MM cells. The results of the present study therefore suggested that andrographolide inhibited multiple myeloma cells via the TLR4/NF-κB signaling pathway.

  4. Inhibition factors and Kinetic model for ammonium inhibition on the anammox process of the SNAD biofilm.

    Science.gov (United States)

    Zheng, Zhaoming; Li, Jun; Ma, Jing; Du, Jia; Wang, Fan; Bian, Wei; Zhang, Yanzhuo; Zhao, Baihang

    2017-03-01

    The aim of the present work was to evaluate the anaerobic ammonium oxidation (anammox) activity of simultaneous partial nitrification, anammox and denitrification (SNAD) biofilm with different substrate concentrations and pH values. Kaldnes rings taken from the SNAD biofilm reactor were incubated in batch tests to determine the anammox activity. Haldane model was applied to investigate the ammonium inhibition on anammox process. As for nitrite inhibition, the NH 4 + -N removal rate of anammox process remained 87.4% of the maximum rate with the NO 2 - -N concentration of 100mg/L. Based on the results of Haldane model, no obvious difference in kinetic coefficients was observed under high or low free ammonia (FA) conditions, indicating that ammonium rather than FA was the true inhibitor for anammox process of SNAD biofilm. With the pH value of 7.0, the r max , Ks and K I of ammonium were 0.209kg NO 2 - -N/kg VSS/day, 9.5mg/L and 422mg/L, respectively. The suitable pH ranges for anammox process were 5.0 to 9.0. These results indicate that the SNAD biofilm performs excellent tolerance to adverse conditions. Copyright © 2016. Published by Elsevier B.V.

  5. Inhibition of auxin movement from the shoot into the root inhibits lateral root development in Arabidopsis

    Science.gov (United States)

    Reed, R. C.; Brady, S. R.; Muday, G. K.

    1998-01-01

    In roots two distinct polar movements of auxin have been reported that may control different developmental and growth events. To test the hypothesis that auxin derived from the shoot and transported toward the root controls lateral root development, the two polarities of auxin transport were uncoupled in Arabidopsis. Local application of the auxin-transport inhibitor naphthylphthalamic acid (NPA) at the root-shoot junction decreased the number and density of lateral roots and reduced the free indoleacetic acid (IAA) levels in the root and [3H]IAA transport into the root. Application of NPA to the basal half of or at several positions along the root only reduced lateral root density in regions that were in contact with NPA or in regions apical to the site of application. Lateral root development was restored by application of IAA apical to NPA application. Lateral root development in Arabidopsis roots was also inhibited by excision of the shoot or dark growth and this inhibition was reversible by IAA. Together, these results are consistent with auxin transport from the shoot into the root controlling lateral root development.

  6. Cordycepin inhibits LPS-induced acute lung injury by inhibiting inflammation and oxidative stress.

    Science.gov (United States)

    Lei, Jiaji; Wei, Youlei; Song, Pengcheng; Li, Yongchao; Zhang, Tianze; Feng, Qingjiang; Xu, Guangquan

    2018-01-05

    Acute lung injury (ALI) is a common severe clinical syndrome in intensive care unit. Inflammation has been reported to play a critical role in the development of ALI. Cordycepin, an active component isolated from Cordyceps militaris, has been reported to have anti-inflammatory effects. However, the anti-inflammatory effects of cordycepin on LPS-induced ALI remain unclear. Therefore, in the present study, we assessed whether cordycepin could attenuate ALI induced by LPS. The mice were conditioned with cordycepin 1h before intranasal instillation of LPS. Lung wet/dry (W/D) ratio, MPO activity, MDA content, and inflammatory cytokines production were detected. The expression of NF-κB p65, I-κB, Nrf2, and HO-1 were detected by western blot analysis. We found that LPS significantly increased lung wet/dry (W/D) ratio, MPO activity, MDA content, and inflammatory cytokines production. However, the increases were significantly inhibited by treatment of cordycepin. LPS-induced NF-κB activation was also suppressed by cordycepin. In addition, cordycepin was found to up-regulate the expression of Nrf2 and HO-1 in a dose-dependent manner. In conclusion, our results demonstrated that cordycepin could attenuate LPS-induced ALI effectively, probably due to inhibition of inflammation and oxidative stress. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Inhibition of mushroom tyrosinase by a newly synthesized ligand: inhibition kinetics and computational simulations.

    Science.gov (United States)

    Alijanianzadeh, Mahdi; Saboury, Ali Akbar; Ganjali, Mohammad Reza; Hadi-Alijanvand, Hamid; Moosavi-Movahedi, Ali Akbar

    2012-01-01

    Alterations in the synthesis of melanin contribute to a number of diseases; therefore, the design of new tyrosinase inhibitors is very important. Mushroom tyrosinase (MT) is a metalloenzyme, which plays an important role in melanin biosynthesis. In this study, the inhibitory effect of a novel designed compound, i.e. 2-((1Z)-(2-(2,4-dinitrophenyl)hydrazin-1-ylidene)methyl)phenol, as a specific ligand which can bind to the copper ion of MT, has been assessed. The ligand was found to competitively inhibit both the cresolase and catecholase activities of MT, with small inhibition constants of 2.8 and 2.6 μM, respectively. Intrinsic fluorescence studies were performed to gain more information on the binding constants. Docking results indicated that the ligand binds to copper ions in the active site of MT via the OH group of the ligand. The ligand makes four hydrogen bonds with aspartic acid and one hydrogen bond with the histidine residue in the active site. Molecular dynamics results show that ligand binds to the MT via both electrostatic and hydrophobic interactions with its different parts.

  8. Sex differences in emotional contexts modulation on response inhibition.

    Science.gov (United States)

    Ramos-Loyo, Julieta; Angulo-Chavira, Armando; Llamas-Alonso, Luis A; González-Garrido, Andrés A

    2016-10-01

    The aim of the present study was to explore sex differences in the effects that emotional contexts exert on the temporal course of response inhibition using event-related potentials (ERP). Participants performed a Go-NoGo response inhibition task under 3 context conditions: with 1) neutral background stimuli, and 2) pleasant, and 3) unpleasant emotional contexts. No sex differences were found in relation to accuracy. Women showed higher N2NoGo amplitudes than men in both emotional contexts; whereas during inhibition men tended to show higher P3NoGo amplitudes than women in the unpleasant context. Both groups experienced a relevant effect of the presence of the unpleasant context during inhibition processing, as shown by the enhancement of the N2NoGo amplitudes in frontal regions compared to results from the neutral and pleasant conditions. In addition, women showed differences between the pleasant and unpleasant contexts, with the latter inducing higher amplitude values. Only in men did inhibition accuracy correlate with higher N2NoGo and lower P3NoGo amplitudes in the emotional context conditions. These findings suggest that when an inhibition task is performed in an emotionally-neutral background context no sex differences are observed in either accuracy or ERP components. However, when the emotional context was introduced -especially the unpleasant one- some gender differences did become evident. The higher N2NoGo amplitude at the presence of the unpleasant context may reflect an effect on attention and conflict monitoring. In addition, results suggest that during earlier processing stages, women invested more resources to process inhibition than men. Furthermore, men who invested more neural resources during earlier stages showed better response inhibition than those who did it during later processing stages, more closely-related to cognitive and motor inhibition processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Measuring Feedforward Inhibition and Its Impact on Local Circuit Function.

    Science.gov (United States)

    Hull, Court

    2017-05-01

    This protocol describes a series of approaches to measure feedforward inhibition in acute brain slices from the cerebellar cortex. Using whole-cell voltage and current clamp recordings from Purkinje cells in conjunction with electrical stimulation of the parallel fibers, these methods demonstrate how to measure the relationship between excitation and inhibition in a feedforward circuit. This protocol also describes how to measure the impact of feedforward inhibition on Purkinje cell excitability, with an emphasis on spike timing. © 2017 Cold Spring Harbor Laboratory Press.

  10. Blue light does not inhibit nodulation in Sesbania rostrata.

    Science.gov (United States)

    Shimomura, Aya; Arima, Susumu; Hayashi, Makoto; Maymon, Maskit; Hirsch, Ann M; Suzuki, Akihiro

    2017-01-02

    Earlier, we reported that root nodulation was inhibited by blue light irradiation of Lotus japonicus. Because some legumes do not establish nodules exclusively on underground roots, we investigated whether nodule formation in Sesbania rostrata, which forms both root and "stem" nodules following inoculation with Azorhizobium caulinodans, is inhibited by blue light as are L. japonicus nodules. We found that neither S. rostrata nodulation nor nitrogen fixation was inhibited by blue light exposure. Moreover, although A. caulinodans proliferation was not affected by blue light irradiation, bacterial survival was decreased. Therefore, blue light appears to impose different responses depending on the legume-rhizobial symbiosis.

  11. Antifreeze Protein Mimetic Metallohelices with Potent Ice Recrystallization Inhibition Activity.

    Science.gov (United States)

    Mitchell, Daniel E; Clarkson, Guy; Fox, David J; Vipond, Rebecca A; Scott, Peter; Gibson, Matthew I

    2017-07-26

    Antifreeze proteins are produced by extremophile species to control ice formation and growth, and they have potential applications in many fields. There are few examples of synthetic materials which can reproduce their potent ice recrystallization inhibition property. We report that self-assembled enantiomerically pure, amphipathic metallohelicies inhibited ice growth at just 20 μM. Structure-property relationships and calculations support the hypothesis that amphipathicity is the key motif for activity. This opens up a new field of metallo-organic antifreeze protein mimetics and provides insight into the origins of ice-growth inhibition.

  12. Spike propagation in driven chain networks with dominant global inhibition

    International Nuclear Information System (INIS)

    Chang Wonil; Jin, Dezhe Z.

    2009-01-01

    Spike propagation in chain networks is usually studied in the synfire regime, in which successive groups of neurons are synaptically activated sequentially through the unidirectional excitatory connections. Here we study the dynamics of chain networks with dominant global feedback inhibition that prevents the synfire activity. Neural activity is driven by suprathreshold external inputs. We analytically and numerically demonstrate that spike propagation along the chain is a unique dynamical attractor in a wide parameter regime. The strong inhibition permits a robust winner-take-all propagation in the case of multiple chains competing via the inhibition.

  13. Mechanism of acid corrosion inhibition using magnetic nanofluid

    Science.gov (United States)

    Parekh, Kinnari; Jauhari, Smita; Upadhyay, R. V.

    2016-12-01

    The inhibition effect of magnetic nanofluid on carbon steel in acid solutions was investigated using gravimetric, potentiodynamic and SEM measurement. The inhibition efficiency increases up to 95% and 75% for 51.7 mM concentration, respectively, in 1 M HCl and 1 M H2SO4 medium. The adsorption of nanoparticles to the steel surface forms a barrier between the metal and the aggressive environment, which is responsible for observed inhibition action. The adsorption of nanoparticles on steel surface is supported by the Langmuir and Freundlich adsorption isotherm and surface morphology scanned through SEM.

  14. Response inhibition is associated with white matter microstructure in children

    DEFF Research Database (Denmark)

    Madsen, Kathrine Skak; Baaré, William; Vestergaard, Martin

    2010-01-01

    the relationship between response inhibition, as measured with the stop-signal task, and indices of regional white matter microstructure in typically-developing children. We hypothesized that better response inhibition performance would be associated with higher fractional anisotropy (FA) in fibre tracts within...... to the prediction of performance variability. Observed associations may be related to variation in phase of maturation, to activity-dependent alterations in the network subserving response inhibition, or to stable individual differences in underlying neural system connectivity. (C) 2009 Elsevier Ltd. All rights...... reserved....

  15. Irreversible inhibition of RANK expression as a possible mechanism for IL-3 inhibition of RANKL-induced osteoclastogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Khapli, Shruti M.; Tomar, Geetanjali B.; Barhanpurkar, Amruta P.; Gupta, Navita; Yogesha, S.D.; Pote, Satish T. [National Center for Cell Science, University of Pune Campus, Pune 411 007 (India); Wani, Mohan R., E-mail: mohanwani@nccs.res.in [National Center for Cell Science, University of Pune Campus, Pune 411 007 (India)

    2010-09-03

    Research highlights: {yields} IL-3 inhibits receptor activator of NF-{kappa}B ligand (RANKL)-induced osteoclastogenesis. {yields} IL-3 inhibits RANKL-induced JNK activation. {yields} IL-3 down-regulates expression of c-Fos and NFATc1 transcription factors. {yields} IL-3 down-regulates RANK expression posttranscriptionally and irreversibly. {yields} IL-3 inhibits in vivo RANK expression. -- Abstract: IL-3, a cytokine secreted by activated T lymphocytes, stimulates the proliferation, differentiation and survival of pluripotent hematopoietic stem cells. In this study, we investigated the mechanism of inhibitory action of IL-3 on osteoclast differentiation. We show here that IL-3 significantly inhibits receptor activator of NF-{kappa}B (RANK) ligand (RANKL)-induced activation of c-Jun N-terminal kinase (JNK). IL-3 down-regulates expression of c-Fos and nuclear factor of activated T cells (NFATc1) transcription factors. In addition, IL-3 down-regulates RANK expression posttranscriptionally in both purified osteoclast precursors and whole bone marrow cells. Furthermore, the inhibitory effect of IL-3 on RANK expression was irreversible. Interestingly, IL-3 inhibits in vivo RANK expression in mice. Thus, we provide the first evidence that IL-3 irreversibly inhibits RANK expression that results in inhibition of important signaling molecules induced by RANKL.

  16. Dicumarol inhibition of NADPH:quinone oxidoreductase induces growth inhibition of pancreatic cancer via a superoxide-mediated mechanism.

    Science.gov (United States)

    Cullen, Joseph J; Hinkhouse, Marilyn M; Grady, Matthew; Gaut, Andrew W; Liu, Jingru; Zhang, Yu Ping; Weydert, Christine J Darby; Domann, Frederick E; Oberley, Larry W

    2003-09-01

    NADPH:quinone oxidoreductase (NQO(1)), a homodimeric, ubiquitous, flavoprotein, catalyzes the two-electron reduction of quinones to hydroquinones. This reaction prevents the one-electron reduction of quinones by cytochrome P450 reductase and other flavoproteins that would result in oxidative cycling with generation of superoxide (O(2)(.-)). NQO(1) gene regulation may be up-regulated in some tumors to accommodate the needs of rapidly metabolizing cells to regenerate NAD(+). We hypothesized that pancreatic cancer cells would exhibit high levels of this enzyme, and inhibiting it would suppress the malignant phenotype. Reverse transcription-PCR, Western blots, and activity assays demonstrated that NQO(1) was up-regulated in the pancreatic cancer cell lines tested but present in very low amounts in the normal human pancreas. To determine whether inhibition of NQO(1) would alter the malignant phenotype, MIA PaCa-2 pancreatic cancer cells were treated with a selective inhibitor of NQO(1), dicumarol. Dicumarol increased intracellular production of O(2)(.-), as measured by hydroethidine staining, and inhibited cell growth. Both of these effects were blunted with infection of an adenoviral vector containing the cDNA for manganese superoxide dismutase. Dicumarol also inhibited cell growth, plating efficiency, and growth in soft agar. We conclude that inhibition of NQO(1) increases intracellular O(2)(.-) production and inhibits the in vitro malignant phenotype of pancreatic cancer. These mechanisms suggest that altering the intracellular redox environment of pancreatic cancer cells may inhibit growth and delineate a potential strategy directed against pancreatic cancer.

  17. Arctigenin Inhibits Liver Cancer Tumorigenesis by Inhibiting Gankyrin Expression via C/EBPα and PPARα.

    Science.gov (United States)

    Sun, Ying; Tan, Yu-Jun; Lu, Zhan-Zhao; Li, Bing-Bing; Sun, Cheng-Hong; Li, Tao; Zhao, Li-Li; Liu, Zhong; Zhang, Gui-Min; Yao, Jing-Chun; Li, Jie

    2018-01-01

    Burdock ( Arctium lappa ) is a popular vegetable in China and Japan that is consumed for its general health benefits. The principal active component of burdock is arctigenin, which shows a range of bioactivities in vivo and in vitro . Here, we investigated the potential anti-tumor effects of arctigenin using two human hepatocellular carcinoma (HCC) cell lines, HepG2 and Hep3B, and sought to elucidate its potential mechanisms of action. Our results showed that arctigenin treatment inhibited cell growth in both HepG2 and Hep3B cell lines (IC 50 of 4.74 nM for HepG2 cells, and of 59.27 nM for Hep3B cells). In addition, migration, invasion, and colony formation by HepG2 cells were significantly inhibited by arctigenin. By contrast, treatment of Hep3B cells with arctigenin did not alter these parameters. Arctigenin also significantly reduced the levels of gankyrin mRNA and protein in HepG2 cells, but not in Hep3B cells. A luciferase assay indicated that arctigenin targeted the -450 to -400 region of the gankyrin promoter. This region is also the potential binding site for both C/EBPα and PPARα, as predicted and confirmed by an online software analysis and ChIP assay. Additionally, a co-immunoprecipitation (Co-IP) assay showed that binding between C/EBPα and PPARα was increased in the presence of arctigenin. However, arctigenin did not increase the expression of C/EBPα or PPARα protein. A binding screening assay and liquid chromatography-mass spectrometry (LC-MS) were performed to identify the mechanisms by which arctigenin regulates gankyrin expression. The results suggested that arctigenin could directly increase C/EBPα binding to the gankyrin promoter (-432 to -422 region), but did not affect PPARα binding. Expression of gankyrin, C/EBPα , and PPARα were analyzed in tumor tissues of patients using real-time PCR. Both C/EBPα and PPARα showed negative correlations with gankyrin. In tumor-bearing mice, arctigenin had a significant inhibitory effect on HCC

  18. Arctigenin Inhibits Liver Cancer Tumorigenesis by Inhibiting Gankyrin Expression via C/EBPα and PPARα

    Directory of Open Access Journals (Sweden)

    Ying Sun

    2018-03-01

    Full Text Available Burdock (Arctium lappa is a popular vegetable in China and Japan that is consumed for its general health benefits. The principal active component of burdock is arctigenin, which shows a range of bioactivities in vivo and in vitro. Here, we investigated the potential anti-tumor effects of arctigenin using two human hepatocellular carcinoma (HCC cell lines, HepG2 and Hep3B, and sought to elucidate its potential mechanisms of action. Our results showed that arctigenin treatment inhibited cell growth in both HepG2 and Hep3B cell lines (IC50 of 4.74 nM for HepG2 cells, and of 59.27 nM for Hep3B cells. In addition, migration, invasion, and colony formation by HepG2 cells were significantly inhibited by arctigenin. By contrast, treatment of Hep3B cells with arctigenin did not alter these parameters. Arctigenin also significantly reduced the levels of gankyrin mRNA and protein in HepG2 cells, but not in Hep3B cells. A luciferase assay indicated that arctigenin targeted the -450 to -400 region of the gankyrin promoter. This region is also the potential binding site for both C/EBPα and PPARα, as predicted and confirmed by an online software analysis and ChIP assay. Additionally, a co-immunoprecipitation (Co-IP assay showed that binding between C/EBPα and PPARα was increased in the presence of arctigenin. However, arctigenin did not increase the expression of C/EBPα or PPARα protein. A binding screening assay and liquid chromatography–mass spectrometry (LC–MS were performed to identify the mechanisms by which arctigenin regulates gankyrin expression. The results suggested that arctigenin could directly increase C/EBPα binding to the gankyrin promoter (-432 to -422 region, but did not affect PPARα binding. Expression of gankyrin, C/EBPα, and PPARα were analyzed in tumor tissues of patients using real-time PCR. Both C/EBPα and PPARα showed negative correlations with gankyrin. In tumor-bearing mice, arctigenin had a significant inhibitory

  19. Procedures for evaluating corrosion-inhibiting admixtures for structural concrete

    Science.gov (United States)

    2000-06-01

    The objectives of this research were to (1) develop procedures for evaluating and qualifying corrosion-inhibiting admixtures (CIAs) and (2) recommend performance criteria for their acceptance. Phase I work included a literature review of CIAs, the re...

  20. Functional inhibition of UQCRB suppresses angiogenesis in zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yoon Sun; Jung, Hye Jin [Chemical Genomics National Research Laboratory, Department of Biotechnology, Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Seok, Seung Hyeok [Department of Microbiology and Immunology, Institute for Experimental Animals, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Payumo, Alexander Y.; Chen, James K. [Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305 (United States); Kwon, Ho Jeong, E-mail: kwonhj@yonsei.ac.kr [Chemical Genomics National Research Laboratory, Department of Biotechnology, Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2013-04-19

    Highlights: ► This is the first functional characterization of UQCRB in vivo model. ► Angiogenesis is inhibited with UQCRB loss of function in zebrafish. ► UQCRB is introduced as a prognostic marker for mitochondria- and angiogenesis-related diseases. -- Abstract: As a subunit of mitochondrial complex III, UQCRB plays an important role in complex III stability, electron transport, and cellular oxygen sensing. Herein, we report UQCRB function regarding angiogenesis in vivo with the zebrafish (Danio rerio). UQCRB knockdown inhibited angiogenesis in zebrafish leading to the suppression of VEGF expression. Moreover, the UQCRB-targeting small molecule terpestacin also inhibited angiogenesis and VEGF levels in zebrafish, supporting the role of UQCRB in angiogenesis. Collectively, UQCRB loss of function by either genetic and pharmacological means inhibited angiogenesis, indicating that UQCRB plays a key role in this process and can be a prognostic marker of angiogenesis- and mitochondria-related diseases.

  1. Inhibition of bacterial quorum sensing by vanilla extract.

    Science.gov (United States)

    Choo, J H; Rukayadi, Y; Hwang, J-K

    2006-06-01

    The purpose of this study was to search for a novel quorum sensing inhibitor and analyse its inhibitory activity. Quorum sensing inhibition was monitored using the Tn-5 mutant, Chromobacterium violaceum CV026. Vanilla beans (Vanilla planifolia Andrews) were extracted using 75% (v/v) aqueous methanol and added to C. violaceum CV026 cultures. Inhibitory activity was measured by quantifying violacein production using a spectrophotometer. The results have revealed that vanilla extract significantly reduced violacein production in a concentration-dependent manner, indicating inhibition of quorum sensing. Vanilla, a widely used spice and flavour, can inhibit bacterial quorum sensing. The results suggest that the intake of vanilla-containing food materials might promote human health by inhibiting quorum sensing and preventing bacterial pathogenesis. Further studies are required to isolate specific substances from vanilla extract acting as quorum sensing inhibitors.

  2. Nitric oxide inhibits glycogen synthesis in isolated rat hepatocytes

    NARCIS (Netherlands)

    Sprangers, F.; Sauerwein, H. P.; Romijn, J. A.; van Woerkom, G. M.; Meijer, A. J.

    1998-01-01

    There is increasing evidence for the existence of intrahepatic regulation of glucose metabolism by Kupffer cell products. Nitric oxide (NO) is known to inhibit gluconeogenic flux through pyruvate carboxylase and phosphoenolpyruvate carboxykinase. However, NO may also influence glucose metabolism at

  3. Ginsenoside Rb1 Reduces Nitric Oxide Production via Inhibition of ...

    African Journals Online (AJOL)

    Ginsenoside Rb1 Reduces Nitric Oxide Production via Inhibition of Nuclear Factor-κB Activation in Interleukin-1β- Stimulated SW1353 Chondrosarcoma Cells. P Jia, G Chen, R Li, X Rong, G Zhou, Y Zhong ...

  4. Inhibiting DNA Polymerases as a Therapeutic Intervention against Cancer

    Directory of Open Access Journals (Sweden)

    Anthony J. Berdis

    2017-11-01

    Full Text Available Inhibiting DNA synthesis is an important therapeutic strategy that is widely used to treat a number of hyperproliferative diseases including viral infections, autoimmune disorders, and cancer. This chapter describes two major categories of therapeutic agents used to inhibit DNA synthesis. The first category includes purine and pyrmidine nucleoside analogs that directly inhibit DNA polymerase activity. The second category includes DNA damaging agents including cisplatin and chlorambucil that modify the composition and structure of the nucleic acid substrate to indirectly inhibit DNA synthesis. Special emphasis is placed on describing the molecular mechanisms of these inhibitory effects against chromosomal and mitochondrial DNA polymerases. Discussions are also provided on the mechanisms associated with resistance to these therapeutic agents. A primary focus is toward understanding the roles of specialized DNA polymerases that by-pass DNA lesions produced by DNA damaging agents. Finally, a section is provided that describes emerging areas in developing new therapeutic strategies targeting specialized DNA polymerases.

  5. Hyperoxia Inhibits T Cell Activation in Mice

    Science.gov (United States)

    Hughes-Fulford, M.; Meissler, J.; Aguayo, E. T.; Globus, R.; Aguado, J.; Candelario, T.

    2013-02-01

    , spleens were removed and the splenocytes were isolated and kept as individual biological samples. We have also examined transcription factors (JASPAR) and pathways of the immune system to help us understand the mechanism of regulation. Results: Our recent mouse immunology experiment aboard STS-131 suggests that the early T cell immune response was inhibited in animals that have been exposed to spaceflight, even 24 hours after return to earth. Moreover, recent experiments in hyperoxic mice show that many of the same genes involved in early T cell activation were altered. Specifically, expression of IL-2Rα, Cxcl2, TNFα, FGF2, LTA and BCL2 genes are dysregulated in mice exposed to hyperoxia. Conclusions: If these hyperoxia-induced changes of gene expression in early T cell activation are additive to the changes seen in the microgravity of spaceflight, there could be an increased infection risk to EVA astronauts, which should be addressed prior to conducting a Mars or other long-term mission.

  6. Angiotensin-converting enzyme inhibition by Brazilian plants.

    Science.gov (United States)

    Braga, Fernão C; Serra, Carla P; Viana, Nilton S; Oliveira, Alaíde B; Côrtes, Steyner F; Lombardi, Júlio A

    2007-07-01

    The potential antihypertensive activity of Brazilian plants was evaluated in vitro by its ability to inhibit the angiotensin-converting enzyme (ACE). Forty-four plants belonging to 30 families were investigated. Plants were selected based on their popular use as antihypertensive and/or diuretics. The following plants presented significant ACE inhibition rates: Calophyllum brasiliense, Combretum fruticosum, Leea rubra, Phoenix roebelinii and Terminalia catappa.

  7. [Activity of polygalacturonase-inhibiting protein of banana fruit tissues].

    Science.gov (United States)

    Bulantseva, E A; Thang, Nguen; Buza, N L; Krinitsyna, A A; Protsenko, M A

    2005-01-01

    The activity of polygalacturonase and the protein inhibiting this enzyme, which affected polygalacturonases of phytopathogenic fungi Verticillium dahliae and Gloesporium musarium, were detected in banana (Musa acumthata L.) fruit of cultivars Cavendish and Korolevskii. The polygalacturonase from banana fruit was inhibited by the preparations of the protein inhibitor not only from bananas but also from potato (Solanum tuberosum L.) tubers and pepper (Capsicum annuum L.) fruit.

  8. Potent protein glycation inhibition of plantagoside in Plantago major seeds.

    Science.gov (United States)

    Matsuura, Nobuyasu; Aradate, Tadashi; Kurosaka, Chihiro; Ubukata, Makoto; Kittaka, Shiho; Nakaminami, Yuri; Gamo, Kanae; Kojima, Hiroyuki; Ohara, Mitsuharu

    2014-01-01

    Plantagoside (5,7,4',5'-tetrahydroxyflavanone-3'-O-glucoside) and its aglycone (5,7,3',4',5'-pentahydroxyflavanone), isolated from a 50% ethanol extract of Plantago major seeds (Plantaginaceae), were established to be potent inhibitors of the Maillard reaction. These compounds also inhibited the formation of advanced glycation end products in proteins in physiological conditions and inhibited protein cross-linking glycation. These results indicate that P. major seeds have potential therapeutic applications in the prevention of diabetic complications.

  9. Combined PDGFR and HDAC Inhibition Overcomes PTEN Disruption in Chordoma

    OpenAIRE

    Lee, Dae-Hee; Zhang, Ying; Kassam, Amin B.; Park, Myung-Jin; Gardner, Paul; Prevedello, Daniel; Henry, Stephanie; Horbinski, Craig; Beumer, Jan H.; Tawbi, Hussein; Williams, Brian J.; Shaffrey, Mark E.; Egorin, Merrill J.; Abounader, Roger; Park, Deric M.

    2015-01-01

    Background The majority of chordomas show activation of the platelet-derived growth factor receptor (PDGFR). Based on in vitro intertumoral variation in response to recombinant PDGF protein and PDGFR inhibition, and variable tumor response to imatinib, we hypothesized that chordomas resistant to PDGFR inhibition may possess downstream activation of the pathway. Methods Molecular profiling was performed on 23 consecutive chordoma primary tissue specimens. Primary cultures established from 20 o...

  10. DMSO inhibits human platelet activation through cyclooxygenase-1 inhibition. A novel agent for drug eluting stents?

    International Nuclear Information System (INIS)

    Asmis, Lars; Tanner, Felix C.; Sudano, Isabella; Luescher, Thomas F.; Camici, Giovanni G.

    2010-01-01

    Background: DMSO is routinely infused together with hematopoietic cells in patients undergoing myeloablative therapy and was recently found to inhibit smooth muscle cells proliferation and arterial thrombus formation in the mouse by preventing tissue factor (TF), a key activator of the coagulation cascade. This study was designed to investigate whether DMSO prevents platelet activation and thus, whether it may represent an interesting agent to be used on drug eluting stents. Methods and results: Human venous blood from healthy volunteers was collected in citrated tubes and platelet activation was studied by cone and platelet analyzer (CPA) and rapid-platelet-function-assay (RPFA). CPA analysis showed that DMSO-treated platelets exhibit a lower adherence in response to shear stress (-15.54 ± 0.9427%, n = 5, P < 0.0001 versus control). Additionally, aggregometry studies revealed that DMSO-treated, arachidonate-stimulated platelets had an increased lag phase (18.0% ± 4.031, n = 9, P = 0.0004 versus control) as well as a decreased maximal aggregation (-6.388 ± 2.212%, n = 6, P = 0.0162 versus control). Inhibitory action of DMSO could be rescued by exogenous thromboxane A2 and was mediated, at least in part, by COX-1 inhibition. Conclusions: Clinically relevant concentrations of DMSO impair platelet activation by a thromboxane A2-dependent, COX-1-mediated effect. This finding may be crucial for the previously reported anti-thrombotic property displayed by DMSO. Our findings support a role for DMSO as a novel drug to prevent not only proliferation, but also thrombotic complications of drug eluting stents.

  11. Germination inhibition of Bacillus cereus spores: impact of the lipophilic character of inhibiting compounds.

    Science.gov (United States)

    van Melis, C C J; Almeida, C Bravo; Kort, R; Groot, M N Nierop; Abee, T

    2012-11-15

    In this study, the impact of a range of organic acids and structurally similar alcohols with three to six carbon backbones and increasing lipophilic character, were tested on the germination behavior of B. cereus ATCC 14579 spores. This approach allowed substantiating whether the effectivity of the various compounds was largely dictated by membrane interference or a classic weak acid acidification effect. The octanol-water partition coefficient (log P(oct/water)) ranges from 0.25/0.33 to 2.03/1.96 for propanol/undissociated propionic acid and hexanol/undissociated hexanoic acid, respectively. Performance of germination assays at neutral (pH7) and acidic conditions (pH5.5) allowed for a comparative analysis of the action of dissociated versus undissociated acids, and the presumed pH-independent effect of the corresponding alcohols. Germination assays, based on both continuously measured optical density and time-based plating experiments, and microscopic observations demonstrated the correlation between the lipophilic character of the selected compounds and their inhibiting effect on spore germination. Real-time fluorescence based assays showed that membrane integrity in dormant spores was maintained in the presence of the tested inhibitors. Lowering the critical concentration of inhibitors by a one-step washing procedure resulted in the onset of nutrient-induced germination, indicating the reversible nature of the inhibition process. Furthermore, blocking of nutrient-induced germination in the presence of inhibitory concentrations of selected lipophilic acids and corresponding alcohols was by-passed upon addition of Ca-dipicolinic acid, pointing to loss of signaling capacity in germinant receptor-mediated germination activity. These findings show that lipophilicity is an important determinant for the ability of the selected acids and corresponding alcohols to accumulate in the spore inner membrane and their ability to act as a germination-inhibitor. Copyright

  12. Substrate and product inhibition of hydrogen production by the extreme thermophile, Caldicellulosiruptor saccharolyticus

    NARCIS (Netherlands)

    Niel, van E.W.J.; Claassen, P.A.M.; Stams, A.J.M.

    2003-01-01

    Substrate and product inhibition of hydrogen production during sucrose fermentation by the extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus was studied. The inhibition kinetics were analyzed with a noncompetitive, nonlinear inhibition model. Hydrogen was the most severe

  13. Inhibition properties of propolis extracts to some clinically important enzymes.

    Science.gov (United States)

    Baltas, Nimet; Yildiz, Oktay; Kolayli, Sevgi

    2016-01-01

    The present study was conducted to envisage inhibition effects of propolis on the crucial enzymes, urease, xanthine oxidase (XO) and acetylcholinesterase (AChE). Some of the antioxidant properties of the propolis samples were determined using the total phenolic content (TPE) and total flavonoids in the eight different ethanolic propolis extracts (EPE) samples. Inhibition values of the enzymes were expressed as inhibition concentration (IC 50 ; mg/mL or μg/mL) causing 50% inhibition of the enzymes with donepezil, acetohydroxamic acid and allopurinol as reference inhibitors. All the propolis extracts exhibited variable inhibition effects on these enzymes, but the higher the phenolic contents the lower the inhibitions values (IC 50 = 0.074 to 1.560 mg/mL). IC 50 values of the P5 propolis sample having the highest TPE, obtained from Zonguldak, for AChE, urease and XO were 0.081 ± 0.009, 0.080 ± 0.006 and 0.074 ± 0.011 μg/mL, respectively. The EPE proved to be a good source of inhibitor agents that can be used as natural inhibitors to serve human health.

  14. Magnetoencephalographic signatures of right prefrontal cortex involvement in response inhibition.

    Science.gov (United States)

    Hege, Maike A; Preissl, Hubert; Stingl, Krunoslav T

    2014-10-01

    The prefrontal cortex has a pivotal role in top-down control of cognitive and sensory functions. In complex go-nogo tasks, the right dorsolateral prefrontal cortex is considered to be important for guiding the response inhibition. However, little is known about the temporal dynamics and neurophysiological nature of this activity. To address this issue, we recorded magnetoencephalographic brain activity in 20 women during a visual go-nogo task. The right dorsolateral prefrontal cortex showed an increase for the amplitude of the event-related fields and an increase in induced alpha frequency band activity for nogo in comparison to go trials. The peak of this prefrontal activity preceded the mean reaction time of around 360 ms for go trials, and thus supports the proposed role of right dorsolateral prefrontal cortex in gating the response inhibition and further suggests that right prefrontal alpha band activity might be involved in this gating. However, the results in right dorsolateral prefrontal cortex were similar for both successful and unsuccessful response inhibition. In these conditions, we instead observed pre- and poststimulus differences in alpha band activity in occipital and central areas. Thus, successful response inhibition seemed to additionally depend on prestimulus anticipatory alpha desynchronization in sensory areas as it was reduced prior to unsuccessful response inhibition. In conclusion, we suggest a role for functional inhibition by alpha synchronization not only in sensory, but also in prefrontal areas. Copyright © 2014 Wiley Periodicals, Inc.

  15. Cooperative inhibition of acetylcholinesterase activities by hexachlorophene in human erythrocytes.

    Science.gov (United States)

    Matsumura, H; Matsuoka, M; Igisu, H; Ikeda, M

    1997-01-01

    Hexachlorophene (HCP), pentachlorophenol (PCP), 2,4,5-trichlorophenol (2,4,5-TCP) and 2,4,6-trichlorophenol (2,4,6-TCP) all hemolyzed washed human erythrocytes and inhibited acetylcholinesterase (AchE) activities in erythrocyte membrane. HCP was much more potent in either effect than any other compound examined. The inhibition of AchE activities by HCP was reversed on adding albumin. The dose-response curves by HCP and PCP were sigmoidal, indicating cooperative inhibition, while those by 2,4,5-TCP and 2,4,6-TCP were not. Furthermore, the cooperativity of the inhibition by HCP was greater than by PCP. Differing from that by PCP, the cooperativity of inhibition increased depending on the temperature (13, 25, 37 degrees C) and decreased when the membrane was treated with Triton X-100. The cooperativity was also decreased in the presence of albumin. On a Scatchard plot analysis, erythrocyte membranes appeared to have multiple binding sites of different affinities for HCP; binding of HCP to the low affinity site [dissociation constant (Kd) 4.7 x 10(-5) M] seemed to be responsible for the observed cooperative inhibition of AchE activities. Neither neostigmine nor fenitrothion altered the cooperativity. HCP seems to be the most potent cooperative inhibitor of AchE in human erythrocyte membranes known to date. HCP may be useful to examine AchE and milieu in human erythrocyte membranes.

  16. Acrolein in cigarette smoke inhibits T-cell responses.

    Science.gov (United States)

    Lambert, Cherie; McCue, Jesica; Portas, Mary; Ouyang, Yanli; Li, JiMei; Rosano, Thomas G; Lazis, Alexander; Freed, Brian M

    2005-10-01

    Cigarette smoking inhibits T-cell responses in the lungs, but the immunosuppressive compounds have not been fully identified. Cigarette smoke extracts inhibit IL-2, IFN-gamma, and TNF-alpha production in stimulated lymphocytes obtained from peripheral blood, even when the extracts were diluted 100-fold to 1000-fold. The objective of these studies was to identify the immunosuppressive compounds found in cigarette smoke. Gas chromatography/mass spectroscopy and HPLC were used to identify and quantitate volatile compounds found in cigarette smoke extracts. Bioactivity was measured by viability and production of cytokine mRNA and protein levels in treated human lymphocytes. The vapor phase of the cigarette smoke extract inhibited cytokine production, indicating that the immunosuppressive compounds were volatile. Among the volatile compounds identified in cigarette smoke extracts, only the alpha,beta-unsaturated aldehydes, acrolein (inhibitory concentration of 50% [IC50] = 3 micromol/L) and crotonaldehyde (IC50 = 6 micromol/L), exhibited significant inhibition of cytokine production. Although the levels of aldehydes varied 10-fold between high-tar (Camel) and ultralow-tar (Carlton) extracts, even ultralow-tar cigarettes produced sufficient levels of acrolein (34 micromol/L) to suppress cytokine production by >95%. We determined that the cigarette smoke extract inhibited transcription of cytokine genes. The inhibitory effects of acrolein could be blocked with the thiol compound N-acetylcysteine. The vapor phase from cigarette smoke extracts potently suppresses cytokine production. The compound responsible for this inhibition appears to be acrolein.

  17. The Inhibition of Lipase and Glucosidase Activities by Acacia Polyphenol

    Directory of Open Access Journals (Sweden)

    Nobutomo Ikarashi

    2011-01-01

    Full Text Available Acacia polyphenol (AP extracted from the bark of the black wattle tree (Acacia mearnsii is rich in unique catechin-like flavan-3-ols, such as robinetinidol and fisetinidol. In an in vitro study, we measured the inhibitory activity of AP on lipase and glucosidase. In addition, we evaluated the effects of AP on absorption of orally administered olive oil, glucose, maltose, sucrose and starch solution in mice. We found that AP concentration-dependently inhibited the activity of lipase, maltase and sucrase with an IC50 of 0.95, 0.22 and 0.60 mg ml−1, respectively. In ICR mice, olive oil was administered orally immediately after oral administration of AP solution, and plasma triglyceride concentration was measured. We found that AP significantly inhibited the rise in plasma triglyceride concentration after olive oil loading. AP also significantly inhibited the rise in plasma glucose concentration after maltose and sucrose loading, and this effect was more potent against maltose. AP also inhibited the rise in plasma glucose concentration after glucose loading and slightly inhibited it after starch loading. Our results suggest that AP inhibits lipase and glucosidase activities, which leads to a reduction in the intestinal absorption of lipids and carbohydrates.

  18. Off With the Old: Mindfulness Practice Improves Backward Inhibition

    Directory of Open Access Journals (Sweden)

    Jonathan eGreenberg

    2013-01-01

    Full Text Available Mindfulness practice has been linked to reduced depressive rumination and described as involving inhibition of information that has been relevant in the past and is no longer relevant in the present moment. Backward inhibition (BI is considered to be one of the purest measures of task set inhibition, and impaired BI has been linked to depressive rumination. BI was contrasted with Competitor Rule Suppression (CRS, which is another phenomenon observed in task switching, yet one which involves episodic memory tagging of information that is currently conflicting rather than active inhibition. Although similar at baseline level, a randomly assigned group (n=38 who underwent an eight session mindfulness training program exhibited improved BI but not CRS compared to a waiting list group (n=38. Findings indicate that mindfulness improves the specific component of task set inhibition, which has previously been linked to reduced rumination. Implications regarding the potential role of task set inhibition in mediating between mindfulness and reduced rumination, as well as the role of mindfulness in being in the present moment are discussed.

  19. Cocaine Inhibition of Nicotinic Acetylcholine ReceptorsInfluences Dopamine Release

    Directory of Open Access Journals (Sweden)

    Alexandra eAcevedo-Rodriguez

    2014-09-01

    Full Text Available Nicotinic acetylcholine receptors (nAChRs potently regulate dopamine (DA release in the striatum and alter cocaine’s ability to reinforce behaviors. Since cocaine is a weak nAChR inhibitor, we hypothesized that cocaine may alter DA release by inhibiting the nAChRs in DA terminals in the striatum and thus contribute to cocaine's reinforcing properties primarily associated with the inhibition of DA transporters. We found that biologically relevant concentrations of cocaine can mildly inhibit nAChR-mediated currents in midbrain DA neurons and consequently alter DA release in the dorsal and ventral striatum. At very high concentrations, cocaine also inhibits voltage-gated Na channels in DA neurons. Furthermore, our results show that partial inhibition of nAChRs by cocaine reduces evoked DA release. This diminution of DA release via nAChR inhibition more strongly influences release evoked at low or tonic stimulation frequencies than at higher (phasic stimulation frequencies, particularly in the dorsolateral striatum. This cocaine-induced shift favoring phasic DA release may contribute to the enhanced saliency and motivational value of cocaine-associated memories and behaviors.

  20. Phosphatidic acid inhibits ceramide 1-phosphate-stimulated macrophage migration.

    Science.gov (United States)

    Ouro, Alberto; Arana, Lide; Rivera, Io-Guané; Ordoñez, Marta; Gomez-Larrauri, Ana; Presa, Natalia; Simón, Jorge; Trueba, Miguel; Gangoiti, Patricia; Bittman, Robert; Gomez-Muñoz, Antonio

    2014-12-15

    Ceramide 1-phosphate (C1P) was recently demonstrated to potently induce cell migration. This action could only be observed when C1P was applied exogenously to cells in culture, and was inhibited by pertussis toxin. However, the mechanisms involved in this process are poorly understood. In this work, we found that phosphatidic acid (PA), which is structurally related to C1P, displaced radiolabeled C1P from its membrane-binding site and inhibited C1P-stimulated macrophage migration. This effect was independent of the saturated fatty acid chain length or the presence of a double bond in each of the fatty acyl chains of PA. Treatment of RAW264.7 macrophages with exogenous phospholipase D (PLD), an enzyme that produces PA from membrane phospholipids, also inhibited C1P-stimulated cell migration. Likewise, PA or exogenous PLD inhibited C1P-stimulated extracellularly regulated kinases (ERK) 1 and 2 phosphorylation, leading to inhibition of cell migration. However, PA did not inhibit C1P-stimulated Akt phosphorylation. It is concluded that PA is a physiological regulator of C1P-stimulated macrophage migration. These actions of PA may have important implications in the control of pathophysiological functions that are regulated by C1P, including inflammation and various cellular processes associated with cell migration such as organogenesis or tumor metastasis. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Common neural substrates for inhibition of spoken and manual responses.

    Science.gov (United States)

    Xue, Gui; Aron, Adam R; Poldrack, Russell A

    2008-08-01

    The inhibition of speech acts is a critical aspect of human executive control over thought and action, but its neural underpinnings are poorly understood. Using functional magnetic resonance imaging and the stop-signal paradigm, we examined the neural correlates of speech control in comparison to manual motor control. Initiation of a verbal response activated left inferior frontal cortex (IFC: Broca's area). Successful inhibition of speech (naming of letters or pseudowords) engaged a region of right IFC (including pars opercularis and anterior insular cortex) as well as presupplementary motor area (pre-SMA); these regions were also activated by successful inhibition of a hand response (i.e., a button press). Moreover, the speed with which subjects inhibited their responses, stop-signal reaction time, was significantly correlated between speech and manual inhibition tasks. These findings suggest a functional dissociation of left and right IFC in initiating versus inhibiting vocal responses, and that manual responses and speech acts share a common inhibitory mechanism localized in the right IFC and pre-SMA.

  2. Inhibition of multiplication of herpes simplex virus by caffeic acid.

    Science.gov (United States)

    Ikeda, Keiko; Tsujimoto, Kazuko; Uozaki, Misao; Nishide, Mitsunori; Suzuki, Yukiko; Koyama, A Hajime; Yamasaki, Hisashi

    2011-10-01

    Hot water extracts of coffee grinds and commercial instant coffee solutions have been shown to exhibit marked antiviral and virucidal activities against herpes simplex virus type 1 (HSV-1). Specifically, it has been shown that caffeine and N-methyl-pyridinium formate inhibit the multiplication of HSV-1 in HEp-2 cells. The present study examined the virological properties and the antiviral activity of caffeic acid against HSV-1. Caffeic acid inhibited the multiplication of HSV-1 in vitro, while chlorogenic acid, a caffeic acid ester with quinic acid, did not. These reagents did not have a direct virucidal effect. The one-step growth curve of HSV-1 showed that the addition of caffeic acid at 8 h post infection (h p.i.) did not significantly affect the formation of progeny viruses. An analysis of the influence of the time of caffeic acid addition, revealed that addition at an early time post infection remarkably inhibited the formation of progeny infectious virus in the infected cells, but its addition after 6 h p.i. (i.e., the time of the completion of viral genome replication) did not efficiently inhibit this process. These results indicate that caffeic acid inhibits HSV-1 multiplication mainly before the completion of viral DNA replication, but not thereafter. Although caffeic acid showed some cytotoxicity by prolonged incubation, the observed antiviral activity is likely not the secondary result of the cytotoxic effect of the reagent, because the inhibition of the virus multiplication was observed before appearance of the notable cytotoxicity.

  3. Highly reflective reasoners show no signs of belief inhibition.

    Science.gov (United States)

    Svedholm-Häkkinen, Annika M

    2015-01-01

    The processes underlying individual differences in reasoning performance are not entirely understood. What do people who do well on reasoning tasks where beliefs and logic conflict do differently from other people? Because abundant evidence shows that even poorer reasoners detect these conflicts, it has been suggested that individual differences in reasoning performance arise from inhibition failures later in the reasoning process. The present paper argues that a minority of highly skilled reasoners may deviate from this general reasoning process from an early stage. Two studies investigated signs of belief inhibition using a lexical access paradigm (Study 1) and a negative priming paradigm (Study 2). Study 1 showed that while other people exhibited signs of belief inhibition following a belief-logic conflict, people with the highest disposition for cognitive reflection did not. In Study 2, this finding was replicated and similar results were also obtained when comparing groups with higher and lower general cognitive ability. Two possible explanations are discussed. The reasoners with a highly reflective cognitive style or high general cognitive ability may have engaged and inhibited belief processing but if so, they may have been exceptionally efficient at recovering from it, wherefore no belief inhibition effects were found. An alternative account is that these reasoners started Type 2 processing directly, without first engaging in and then inhibiting belief-based processing. Under either explanation, the results indicate that individual differences in reasoning may partly arise from differences that occur early in the reasoning process. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Gingival tissue-produced inhibition of platelet aggregation and the loss of inhibition in streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Kawamura, Keiichiroh; Tamai, Kazuharu; Shirakawa, Masaharu; Okamoto, Hiroshi; Dohi, Toshihiro; Tsujimoto, Akira

    1988-01-01

    Addition of medium incubated with normal rat gingival tissue to platelet-rich plasma inhibited ADP-induced platelet aggregation. The ability of rat gingiva to produce activity inhibiting platelet aggregation was enhanced by the addition of arachidonic acid. Diabetic rat gingiva failed to inhibit platelet aggregation but did produce the anti-platelet aggregating activity in the presence of arachidonic acid. Indomethacin blocked the production of anti-platelet aggregating activity. There was no difference in conversion of [1- 14 C]arachidonic acid to prostaglandins by normal and diabetic rat gingiva. These results suggest that an arachidonic acid metabolite released from gingiva during incubation inhibits platelet aggregation, and the synthesis of the metabolite is impaired in diabetic rat gingiva. A decrease in availability of arachidonic acid may be a causal factor of the defect in diabetic rat gingiva. (author)

  5. Dihydrotestosterone inhibits hair growth in mice by inhibiting insulin-like growth factor-I production in dermal papillae.

    Science.gov (United States)

    Zhao, Juan; Harada, Naoaki; Okajima, Kenji

    2011-10-01

    We demonstrated that insulin-like growth factor-I (IGF-I) production in dermal papillae was increased and hair growth was promoted after sensory neuron stimulation in mice. Although the androgen metabolite dihydrotestosterone (DHT) inhibits hair growth by negatively modulating growth-regulatory effects of dermal papillae, relationship between androgen metabolism and IGF-I production in dermal papillae is not fully understood. We examined whether DHT inhibits IGF-I production by inhibiting sensory neuron stimulation, thereby preventing hair growth in mice. Effect of DHT on sensory neuron stimulation was examined using cultured dorsal root ganglion (DRG) neurons isolated from mice. DHT inhibits calcitonin gene-related peptide (CGRP) release from cultured DRG neurons. The non-steroidal androgen-receptor antagonist flutamide reversed DHT-induced inhibition of CGRP release. Dermal levels of IGF-I and IGF-I mRNA, and the number of IGF-I-positive fibroblasts around hair follicles were increased at 6h after CGRP administration. DHT administration for 3weeks decreased dermal levels of CGRP, IGF-I, and IGF-I mRNA in mice. Immunohistochemical expression of IGF-I and the number of proliferating cells in hair follicles were decreased and hair re-growth was inhibited in animals administered DHT. Co-administration of flutamide and CGRP reversed these changes induced by DHT administration. These observations suggest that DHT may decrease IGF-I production in dermal papillae by inhibiting sensory neuron stimulation through interaction with the androgen receptor, thereby inhibiting hair growth in mice. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. A rhodanine derivative CCR-11 inhibits bacterial proliferation by inhibiting the assembly and GTPase activity of FtsZ.

    Science.gov (United States)

    Singh, Parminder; Jindal, Bhavya; Surolia, Avadhesha; Panda, Dulal

    2012-07-10

    A perturbation of FtsZ assembly dynamics has been shown to inhibit bacterial cytokinesis. In this study, the antibacterial activity of 151 rhodanine compounds was assayed using Bacillus subtilis cells. Of 151 compounds, eight strongly inhibited bacterial proliferation at 2 μM. Subsequently, we used the elongation of B. subtilis cells as a secondary screen to identify potential FtsZ-targeted antibacterial agents. We found that three compounds significantly increased bacterial cell length. One of the three compounds, namely, CCR-11 [(E)-2-thioxo-5-({[3-(trifluoromethyl)phenyl]furan-2-yl}methylene)thiazolidin-4-one], inhibited the assembly and GTPase activity of FtsZ in vitro. CCR-11 bound to FtsZ with a dissociation constant of 1.5 ± 0.3 μM. A docking analysis indicated that CCR-11 may bind to FtsZ in a cavity adjacent to the T7 loop and that short halogen-oxygen, H-bonding, and hydrophobic interactions might be important for the binding of CCR-11 with FtsZ. CCR-11 inhibited the proliferation of B. subtilis cells with a half-maximal inhibitory concentration (IC(50)) of 1.2 ± 0.2 μM and a minimal inhibitory concentration of 3 μM. It also potently inhibited proliferation of Mycobacterium smegmatis cells. Further, CCR-11 perturbed Z-ring formation in B. subtilis cells; however, it neither visibly affected nucleoid segregation nor altered the membrane integrity of the cells. CCR-11 inhibited HeLa cell proliferation with an IC(50) value of 18.1 ± 0.2 μM (∼15 × IC(50) of B. subtilis cell proliferation). The results suggested that CCR-11 inhibits bacterial cytokinesis by inhibiting FtsZ assembly, and it can be used as a lead molecule to develop FtsZ-targeted antibacterial agents.

  7. Allosteric Inhibition of Factor XIIIa. Non-Saccharide Glycosaminoglycan Mimetics, but Not Glycosaminoglycans, Exhibit Promising Inhibition Profile.

    Directory of Open Access Journals (Sweden)

    Rami A Al-Horani

    Full Text Available Factor XIIIa (FXIIIa is a transglutaminase that catalyzes the last step in the coagulation process. Orthostery is the only approach that has been exploited to design FXIIIa inhibitors. Yet, allosteric inhibition of FXIIIa is a paradigm that may offer a key advantage of controlled inhibition over orthosteric inhibition. Such an approach is likely to lead to novel FXIIIa inhibitors that do not carry bleeding risks. We reasoned that targeting a collection of basic amino acid residues distant from FXIIIa's active site by using sulfated glycosaminoglycans (GAGs or non-saccharide GAG mimetics (NSGMs would lead to the discovery of the first allosteric FXIIIa inhibitors. We tested a library of 22 variably sulfated GAGs and NSGMs against human FXIIIa to discover promising hits. Interestingly, although some GAGs bound to FXIIIa better than NSGMs, no GAG displayed any inhibition. An undecasulfated quercetin analog was found to inhibit FXIIIa with reasonable potency (efficacy of 98%. Michaelis-Menten kinetic studies revealed an allosteric mechanism of inhibition. Fluorescence studies confirmed close correspondence between binding affinity and inhibition potency, as expected for an allosteric process. The inhibitor was reversible and at least 9-fold- and 26-fold selective over two GAG-binding proteins factor Xa (efficacy of 71% and thrombin, respectively, and at least 27-fold selective over a cysteine protease papain. The inhibitor also inhibited the FXIIIa-mediated polymerization of fibrin in vitro. Overall, our work presents the proof-of-principle that FXIIIa can be allosterically modulated by sulfated non-saccharide agents much smaller than GAGs, which should enable the design of selective and safe anticoagulants.

  8. Neural inhibition during maximal eccentric and concentric quadriceps contraction: effects of resistance training

    DEFF Research Database (Denmark)

    Aagaard, Per; Simonsen, E.B.; Andersen, J.L.

    2000-01-01

    neuromuscular activation, muscle strength, neural efferent drive, eccentric activation deficiency, force inhibition......neuromuscular activation, muscle strength, neural efferent drive, eccentric activation deficiency, force inhibition...

  9. Inhibition of carbachol-induced formation of inositolphosphates in isolated pancreatic islets

    DEFF Research Database (Denmark)

    Kardasz, A.M.J.; Capito, Kirsten; Hansen, Svend Erik

    1991-01-01

    Medicinsk biokemi, feed-back inhibition, phospholipase C, pancreatic islets, Calcium, proteinkinase C......Medicinsk biokemi, feed-back inhibition, phospholipase C, pancreatic islets, Calcium, proteinkinase C...

  10. Influence of transcutaneous electrical nerve stimulation conditions on disynaptic reciprocal Ia inhibition and presynaptic inhibition in healthy adults.

    Science.gov (United States)

    Takeda, Kazuya; Tanabe, Shigeo; Koyama, Soichiro; Ushiroyama, Kosuke; Naoi, Yuki; Motoya, Ikuo; Sakurai, Hiroaki; Kanada, Yoshikiyo

    2017-03-01

    This study investigated the influence of stimulus conditions of transcutaneous electrical nerve stimulation (TENS) on disynaptic reciprocal Ia inhibition (RI) and presynaptic inhibition (D1 inhibition) in healthy adults. Eight healthy participants received TENS (stimulus frequencies of 50, 100, and 200 Hz) over the deep peroneal nerve and tibialis anterior (TA) muscle in the resting condition for 30 min. At pre- and post-intervention, the RI from the TA to the soleus (SOL) and D1 inhibition of the SOL alpha motor neuron were assessed by evoked electromyography. The results showed that RI was not changed by TENS at any stimulus frequency condition. Conversely, D1 inhibition was significantly changed by TENS regardless of the stimulus frequency. The present results and previous studies pertaining to RI suggest that the resting condition might strongly influence the lack of pre- vs. post-intervention change in the RI. Regarding the D1 inhibition, the present results suggest that the effect of TENS might be caused by post-tetanic potentiation. The knowledge gained from the present study might contribute to a better understanding of fundamental studies of TENS in healthy adults and its clinical application for stroke survivors.

  11. Chlorpromazine inhibits tumour necrosis factor synthesis and cytotoxicity in vitro.

    Science.gov (United States)

    Zinetti, M; Galli, G; Demitri, M T; Fantuzzi, G; Minto, M; Ghezzi, P; Alzani, R; Cozzi, E; Fratelli, M

    1995-01-01

    Chlorpromazine (CPZ) has been previously shown to protect against endotoxin [lipopolysaccharide (LPS)] lethality and inhibit the release of tumour necrosis factor in vivo. We investigated at the cellular level whether this was due to direct inhibition of tumour necrosis factor-alpha (TNF-alpha) synthesis, using LPS-stimulated THP-1 human monocytic leukemia cells. We also studied the effect of CPZ on human TNF-alpha action by assessing TNF-alpha cytotoxicity on mouse fibrosarcoma L929 cells. CPZ (1-100 microM) inhibited TNF-alpha production in THP-1 cells in a dose dependent manner by a maximum of 80%. This effect was comparable to that of two well-known inhibitory drugs, dexamethasone and cyclicAMP. Inhibition was also evident at the mRNA level. On the other hand CPZ (10-25 microM) also inhibited TNF-alpha activity: in fact it reduced the cytotoxicity of TNF-alpha on L929 cells (EC50 was increased four times) and could provide protection even as a post-treatment. CPZ inhibited TNF-induced apoptosis in L929 cells, as detected by analysis of nuclear morphology. However, since we showed that apoptosis was very limited, and was not the main mode of cell death in our conditions, this could not explain the overall protection. Since CPZ did not interfere with either the oligomerization state of TNF-alpha or its receptor binding, our data suggest that it reduced cytotoxicity by inhibiting some steps in the TNF-alpha signalling pathways. Images Figure 1 Figure 4 PMID:8550079

  12. Metformin and Its Sulfenamide Prodrugs Inhibit Human Cholinesterase Activity

    Directory of Open Access Journals (Sweden)

    Magdalena Markowicz-Piasecka

    2017-01-01

    Full Text Available The results of epidemiological and pathophysiological studies suggest that type 2 diabetes mellitus (T2DM may predispose to Alzheimer’s disease (AD. The two conditions present similar glucose levels, insulin resistance, and biochemical etiologies such as inflammation and oxidative stress. The diabetic state also contributes to increased acetylcholinesterase (AChE activity, which is one of the factors leading to neurodegeneration in AD. The aim of this study was to assess in vitro the effects of metformin, phenformin, and metformin sulfenamide prodrugs on the activity of human AChE and butyrylcholinesterase (BuChE and establish the type of inhibition. Metformin inhibited 50% of the AChE activity at micromolar concentrations (2.35 μmol/mL, mixed type of inhibition and seemed to be selective towards AChE since it presented low anti-BuChE activity. The tested metformin prodrugs inhibited cholinesterases (ChE at nanomolar range and thus were more active than metformin or phenformin. The cyclohexyl sulfenamide prodrug demonstrated the highest activity towards both AChE (IC50 = 890 nmol/mL, noncompetitive inhibition and BuChE (IC50 = 28 nmol/mL, mixed type inhibition, while the octyl sulfenamide prodrug did not present anti-AChE activity, but exhibited mixed inhibition towards BuChE (IC50 = 184 nmol/mL. Therefore, these two bulkier prodrugs were concluded to be the most selective compounds for BuChE over AChE. In conclusion, it was demonstrated that biguanides present a novel class of inhibitors for AChE and BuChE and encourages further studies of these compounds for developing both selective and nonselective inhibitors of ChEs in the future.

  13. Task Dominance Determines Backward Inhibition in Task Switching

    Directory of Open Access Journals (Sweden)

    Kerstin Jost

    2017-05-01

    Full Text Available Switching between tasks is assumed to be accompanied by inhibiting currently irrelevant, but competing tasks. A dominant task that strongly interferes with performing a weaker task may receive especially strong inhibition. We tested this prediction by letting participants switch among three tasks that differ in dominance: a location discrimination task with strong stimulus–response bindings (responding with left-hand and right-hand button presses to stimuli presented left or right to the fixation cross was combined with a color/pattern and a shape discrimination task, for which stimulus–response mappings were arbitrary (e.g., left-hand button press mapped to a red stimulus. Across three experiments, the dominance of the location task was documented by faster and more accurate responses than in the other tasks. This even held for incompatible stimulus–response mappings (i.e., right-hand response to a left-presented stimulus and vice versa, indicating that set-level compatibility (i.e., “dimension overlap” was sufficient for making this location task dominant. As a behavioral marker for backward inhibition, we utilized n-2 repetition costs that are defined by higher reaction times for a switch back to a just abandoned and thus just inhibited task (ABA sequence than for a switch to a less recently inhibited task (CBA, n-2 non-repetition. Reliable n-2 task repetition costs were obtained for all three tasks. Importantly, these costs were largest for the location task, suggesting that inhibition indeed was stronger for the dominant task. This finding adds to other evidence that the amount of inhibition is adjusted in a context-sensitive way.

  14. DIGESTION PRODUCTS OF THE PH20 HYALURONIDASE INHIBIT REMYELINATION

    Science.gov (United States)

    Preston, Marnie; Gong, Xi; Su, Weiping; Matsumoto, Steven G.; Banine, Fatima; Winkler, Clayton; Foster, Scott; Xing, Rubing; Struve, Jaime; Dean, Justin; Baggenstoss, Bruce; Weigel, Paul H.; Montine, Thomas J.; Back, Stephen A.; Sherman, Larry S.

    2012-01-01

    OBJECTIVE Oligodendrocyte progenitor cells (OPCs) recruited to demyelinating lesions often fail to mature into oligodendrocytes (OLs) that remyelinate spared axons. The glycosaminoglycan hyaluronan (HA) accumulates in demyelinating lesions and has been implicated in the failure of OPC maturation and remyelination. We tested the hypothesis that OPCs in demyelinating lesions express a specific hyaluronidase, and that digestion products of this enzyme inhibit OPC maturation. METHODS Mouse OPCs grown in vitro were analyzed for hyaluronidase expression and activity. Gain of function studies were used to define the hyaluronidases that blocked OPC maturation. Mouse and human demyelinating lesions were assessed for hyaluronidase expression. Digestion products from different hyaluronidases and a hyaluronidase inhibitor were tested for their effects on OPC maturation and functional remyelination in vivo. RESULTS OPCs demonstrated hyaluronidase activity in vitro and expressed multiple hyaluronidases including HYAL1, HYAL2, and PH20. HA digestion by PH20 but not other hyaluronidases inhibited OPC maturation into OLs. In contrast, inhibiting HA synthesis did not influence OPC maturation. PH20 expression was elevated in OPCs and reactive astrocytes in both rodent and human demyelinating lesions. HA-digestion products generated by the PH20 hyaluronidase but not another hyaluronidase inhibited remyelination following lysolecithin-induced demyelination. Inhibition of hyaluronidase activity lead to increased OPC maturation and promoted increased conduction velocities through lesions. INTERPRETATION We determined that PH20 is elevated in demyelinating lesions and that increased PH20 expression is sufficient to inhibit OPC maturation and remyelination. Pharmacological inhibition of PH20 may therefore be an effective way to promote remyelination in multiple sclerosis and related conditions. PMID:23463525

  15. Global Precipitation Measurement (GPM) Safety Inhibit Timeline Tool

    Science.gov (United States)

    Dion, Shirley

    2012-01-01

    The Global Precipitation Measurement (GPM) Observatory is a joint mission under the partnership by National Aeronautics and Space Administration (NASA) and the Japan Aerospace Exploration Agency (JAXA), Japan. The NASA Goddard Space Flight Center (GSFC) has the lead management responsibility for NASA on GPM. The GPM program will measure precipitation on a global basis with sufficient quality, Earth coverage, and sampling to improve prediction of the Earth's climate, weather, and specific components of the global water cycle. As part of the development process, NASA built the spacecraft (built in-house at GSFC) and provided one instrument (GPM Microwave Imager (GMI) developed by Ball Aerospace) JAXA provided the launch vehicle (H2-A by MHI) and provided one instrument (Dual-Frequency Precipitation Radar (DPR) developed by NTSpace). Each instrument developer provided a safety assessment which was incorporated into the NASA GPM Safety Hazard Assessment. Inhibit design was reviewed for hazardous subsystems which included the High Gain Antenna System (HGAS) deployment, solar array deployment, transmitter turn on, propulsion system release, GMI deployment, and DPR radar turn on. The safety inhibits for these listed hazards are controlled by software. GPM developed a "pathfinder" approach for reviewing software that controls the electrical inhibits. This is one of the first GSFC in-house programs that extensively used software controls. The GPM safety team developed a methodology to document software safety as part of the standard hazard report. As part of this process a new tool "safety inhibit time line" was created for management of inhibits and their controls during spacecraft buildup and testing during 1& Tat GSFC and at the Range in Japan. In addition to understanding inhibits and controls during 1& T the tool allows the safety analyst to better communicate with others the changes in inhibit states with each phase of hardware and software testing. The tool was very

  16. Mechanisms of caffeine-induced inhibition of UVB carcinogenesis

    Directory of Open Access Journals (Sweden)

    Allan H Conney

    2013-06-01

    Full Text Available Sunlight-induced nonmelanoma skin cancer is the most prevalent cancer in the United States with more than 2 million cases per year. Several studies have shown an inhibitory effect of caffeine administration on UVB-induced skin cancer in mice, and these studies are paralleled by epidemiology studies that indicate an inhibitory effect of coffee drinking on nonmelanoma skin cancer in humans. Strikingly, decaffeinated coffee consumption had no such inhibitory effect.Mechanism studies indicate that caffeine has a sunscreen effect that inhibits UVB-induced formation of thymine dimers and sunburn lesions in the epidermis of mice. In addition, caffeine administration has a biological effect that enhances UVB-induced apoptosis thereby enhancing the elimination of damaged precancerous cells, and caffeine administration also enhances apoptosis in tumors. Caffeine administration enhances UVB-induced apoptosis by p53-dependent and p53-independent mechanisms. Exploration of the p53-independent effect indicated that caffeine administration enhanced UVB-induced apoptosis by inhibiting the UVB-induced increase in ATR-mediated formation of phospho-Chk1 (Ser345 and abolishing the UVB-induced decrease in cyclin B1 which resulted in caffeine-induced premature and lethal mitosis in mouse skin. In studies with cultured primary human keratinocytes, inhibition of ATR with siRNA against ATR inhibited Chk1 phosphorylation and enhanced UVB-induced apoptosis. Transgenic mice with decreased epidermal ATR function that were irradiated chronically with UVB had 69% fewer tumors at the end of the study compared with irradiated littermate controls with normal ATR function. These results, which indicate that genetic inhibition of ATR (like pharmacologic inhibition of ATR via caffeine inhibits UVB-induced carcinogenesis and supports the concept that ATR-mediated phosphorylation of Chk1 is an important target for caffeine’s inhibitory effect on UVB-induced carcinogenesis.

  17. Inhibition of xanthine oxidase by Puerto Rican plant extracts.

    Science.gov (United States)

    Guerrero, R O; Guzman, A L

    1998-12-01

    This study was conducted to search for xanthine oxidase inhibitors in natural products obtained from plants collected in Puerto Rico and to assess the influence of these extracts in the prevention of cataractogenesis. Allopurinol is currently a xanthine oxidase inhibitor used in the treatment of gout. New alternatives with increased therapeutic activity and less side effects should be investigated. Preclusion of cataractogenesis in diabetic rats is also the focus of this investigation. Natural products in the form of plant extracts from Puerto Rico offer a rich and relatively untapped source for the discovery of new drugs that may address these kind of problems. Nineteen collections of Myrtaceae plant extracts were screened for xanthine oxidase inhibition. A spectrophotometrical method was used employing allopurinol as positive control and a blank as negative control. A protocol of the assay with slight modifications was followed from the literature. Two extracts with the highest percentages of xanthine oxidase inhibition were evaluated for possible prevention of cataractogenesis in streptozotocin diabetic rats. The animals were given to drink these plant extracts ad libitum for three months while controls received water. The appearance of cataracts was assessed physically. Two of the nineteen plant extracts showed high inhibition percentages of xanthine oxidase. Eucalyptus deglupta and Syzygium malaccense displayed 51% and 64% inhibitions (IC50 44.5 micrograms/ml and IC50 51 micrograms/ml), respectively. As for the cataractogenesis inhibition, laboratory animals that drank E. deglupta for three months did not develop cataracts. Two plant extracts provided positive results with varying degrees of inhibition of xanthine oxidase. S. malaccense demonstrated the greatest xanthine oxidase inhibitory activity whereas E. deglupta presented the best finding for cataractogenesis prevention. The procedures used in this investigation are useful for the in vitro screening of

  18. Chlorpromazine inhibits tumour necrosis factor synthesis and cytotoxicity in vitro.

    Science.gov (United States)

    Zinetti, M; Galli, G; Demitri, M T; Fantuzzi, G; Minto, M; Ghezzi, P; Alzani, R; Cozzi, E; Fratelli, M

    1995-11-01

    Chlorpromazine (CPZ) has been previously shown to protect against endotoxin [lipopolysaccharide (LPS)] lethality and inhibit the release of tumour necrosis factor in vivo. We investigated at the cellular level whether this was due to direct inhibition of tumour necrosis factor-alpha (TNF-alpha) synthesis, using LPS-stimulated THP-1 human monocytic leukemia cells. We also studied the effect of CPZ on human TNF-alpha action by assessing TNF-alpha cytotoxicity on mouse fibrosarcoma L929 cells. CPZ (1-100 microM) inhibited TNF-alpha production in THP-1 cells in a dose dependent manner by a maximum of 80%. This effect was comparable to that of two well-known inhibitory drugs, dexamethasone and cyclicAMP. Inhibition was also evident at the mRNA level. On the other hand CPZ (10-25 microM) also inhibited TNF-alpha activity: in fact it reduced the cytotoxicity of TNF-alpha on L929 cells (EC50 was increased four times) and could provide protection even as a post-treatment. CPZ inhibited TNF-induced apoptosis in L929 cells, as detected by analysis of nuclear morphology. However, since we showed that apoptosis was very limited, and was not the main mode of cell death in our conditions, this could not explain the overall protection. Since CPZ did not interfere with either the oligomerization state of TNF-alpha or its receptor binding, our data suggest that it reduced cytotoxicity by inhibiting some steps in the TNF-alpha signalling pathways.

  19. Galanin can inhibit insulin release by a mechanism other than membrane hyperpolarization or inhibition of adenylate cyclase.

    Science.gov (United States)

    Sharp, G W; Le Marchand-Brustel, Y; Yada, T; Russo, L L; Bliss, C R; Cormont, M; Monge, L; Van Obberghen, E

    1989-05-05

    Studies on the mode of action of galanin to inhibit insulin release in RINm5F cells have shown that basal and glyceraldehyde-stimulated release were both inhibited. Galanin was inhibitory at concentrations in the low nanomolar range. Binding studies with 125I-labeled galanin indicated that the RINm5F cells exhibit a single set of sites estimated to be of the order of 30,000 sites/cell. Displacement of 125I-galanin by galanin from the receptor sites occurred over a similar concentration range to that which inhibited insulin release. Half-displacement was achieved with 2 nM galanin. Measurements of bis-(1,3-diethylthiobarbiturate) trimethineoxonol (bis-oxonol) fluorescence showed that galanin hyperpolarized the RINm5F cell plasma membrane. Measurements of intracellular free calcium, [Ca2+]i by means of the fluorescent indicator fura-2 showed that galanin decreased [Ca2+]i. As galanin did not inhibit either basal or glyceraldehyde-stimulated insulin release in the presence of the Ca2+ channel blocker nitrendipine, the hyperpolarization and reduction of Ca2+ entry appear to be a possible explanation for the galanin effects. However, quantitatively, the effects on membrane potential and [Ca2+]i appear to be insufficient to account for the potent inhibition of insulin release. Furthermore, evidence for an additional mechanism of action was obtained from experiments with 12-O-tetradecanoylphorbol-13-acetate (TPA), a phorbol ester which stimulates insulin secretion by at least two mechanisms, one Ca2+ dependent and one Ca2+ independent. TPA-stimulated insulin release was inhibited by galanin over the same concentration range as for the inhibition of glyceraldehyde-stimulated release. Galanin inhibited TPA-stimulated release in the presence of maximally effective concentrations of nitrendipine and in the absence of extracellular Ca2+. These effects cannot be explained by hyperpolarization of the plasma membrane and consequent reduction of Ca2+ entry via the voltage

  20. Curcumin synergizes with resveratrol to inhibit colon cancer.

    Science.gov (United States)

    Majumdar, Adhip P N; Banerjee, Sanjeev; Nautiyal, Jyoti; Patel, Bhaumik B; Patel, Vaishali; Du, Jianhua; Yu, Yingjie; Elliott, Althea A; Levi, Edi; Sarkar, Fazlul H

    2009-01-01

    Development and progression of many malignancies, including colorectal cancer, are associated with activation of multiple signaling pathways. Therefore, inhibition of these signaling pathways with noncytotoxic natural products represents a logical preventive and/or therapeutic approach for colon cancer. Curcumin and resveratrol, both of which inhibit the growth of transformed cells and colon carcinogenesis, were selected to examine whether combining them would be an effective preventive and/or therapeutic strategy for colon cancer. Indeed, the combination of curcumin and resveratrol was found to be more effective in inhibiting growth of p53-positive (wt) and p53-negative colon cancer HCT-116 cells in vitro and in vivo in SCID xenografts of colon cancer HCT-116 (wt) cells than either agent alone. Analysis by Calcusyn software showed synergism between curcumin and resveratrol. The inhibition of tumors in response to curcumin and/or resveratrol was associated with the reduction in proliferation and stimulation of apoptosis accompanied by attenuation of NF-kappaB activity. In vitro studies have further demonstrated that the combinatorial treatment caused a greater inhibition of constitutive activation of EGFR and its family members as well as IGF-1R. Our current data suggest that the combination of curcumin and resveratrol could be an effective preventive/therapeutic strategy for colon cancer.

  1. Two mechanisms of oral malodor inhibition by zinc ions.

    Science.gov (United States)

    Suzuki, Nao; Nakano, Yoshio; Watanabe, Takeshi; Yoneda, Masahiro; Hirofuji, Takao; Hanioka, Takashi

    2018-01-18

    The aim of this study was to reveal the mechanisms by which zinc ions inhibit oral malodor. The direct binding of zinc ions to gaseous hydrogen sulfide (H2S) was assessed in comparison with other metal ions. Nine metal chlorides and six metal acetates were examined. To understand the strength of H2S volatilization inhibition, the minimum concentration needed to inhibit H2S volatilization was determined using serial dilution methods. Subsequently, the inhibitory activities of zinc ions on the growth of six oral bacterial strains related to volatile sulfur compound (VSC) production and three strains not related to VSC production were evaluated. Aqueous solutions of ZnCl2, CdCl2, CuCl2, (CH3COO)2Zn, (CH3COO)2Cd, (CH3COO)2Cu, and CH3COOAg inhibited H2S volatilization almost entirely. The strengths of H2S volatilization inhibition were in the order Ag+ > Cd2+ > Cu2+ > Zn2+. The effect of zinc ions on the growth of oral bacteria was strain-dependent. Fusobacterium nucleatum ATCC 25586 was the most sensitive, as it was suppressed by medium containing 0.001% zinc ions. Zinc ions have an inhibitory effect on oral malodor involving the two mechanisms of direct binding with gaseous H2S and suppressing the growth of VSC-producing oral bacteria.

  2. THE INHIBITION OF DEOXYRIBONUCLEASS I BY HYDEOXY-PIPHENYLS

    Energy Technology Data Exchange (ETDEWEB)

    Gottesfeld, J.M.; Adams, N.H.; El-Badry, A.M.; Moses, V.; Calvin,M.

    1970-09-01

    DNA extracted with certain commercial brands of phenol is resistant to hydrolysis by the endonuclease DNAase I, while DNA extracted with other brands, or prepared by sodium chloride extraction, is susceptible to hydrolysis. The agent responsible for inhibition has been shown to be an oxidation product produced in some phenols. The inhibitor has been separated from other impurities in phenol by paper chromatography, and, by means of infrared and ultraviolet spectroscopy, it has been identified as o-hydroxybiphenyl. The kinetics of inhibition have been studied, and it was found that inhibition arises from direct action on the DNA rather than on the enzyme. Several hydroxybiphenyls and related compounds have been tested for inhibition, and a theory of molecular structure versus inhibitory effectiveness is suggested from this data. From studies on the chemical reversal of inhibition, as well as from ultraviolet spectral studies (in both absorption and circular dichroism), it appears that the mode of action of the inhibitors is hydrogen bonding to, and intercalation between, the basis of the nucleic acid.

  3. Lactobacillus plantarum lipoteichoic acid inhibits biofilm formation of Streptococcus mutans

    Science.gov (United States)

    Ahn, Ki Bum; Baik, Jung Eun; Park, Ok-Jin; Yun, Cheol-Heui

    2018-01-01

    Dental caries is a biofilm-dependent oral disease and Streptococcus mutans is the known primary etiologic agent of dental caries that initiates biofilm formation on tooth surfaces. Although some Lactobacillus strains inhibit biofilm formation of oral pathogenic bacteria, the molecular mechanisms by which lactobacilli inhibit bacterial biofilm formation are not clearly understood. In this study, we demonstrated that Lactobacillus plantarum lipoteichoic acid (Lp.LTA) inhibited the biofilm formation of S. mutans on polystyrene plates, hydroxyapatite discs, and dentin slices without affecting the bacterial growth. Lp.LTA interferes with sucrose decomposition of S. mutans required for the production of exopolysaccharide, which is a main component of biofilm. Lp.LTA also attenuated the biding of fluorescein isothiocyanate-conjugated dextran to S. mutans, which is known to have a high affinity to exopolysaccharide on S. mutans. Dealanylated Lp.LTA did not inhibit biofilm formation of S. mutans implying that D-alanine moieties in the Lp.LTA structure were crucial for inhibition. Collectively, these results suggest that Lp.LTA attenuates S. mutans biofilm formation and could be used to develop effective anticaries agents. PMID:29420616

  4. Menthol binding and inhibition of α7-nicotinic acetylcholine receptors.

    Science.gov (United States)

    Ashoor, Abrar; Nordman, Jacob C; Veltri, Daniel; Yang, Keun-Hang Susan; Al Kury, Lina; Shuba, Yaroslav; Mahgoub, Mohamed; Howarth, Frank C; Sadek, Bassem; Shehu, Amarda; Kabbani, Nadine; Oz, Murat

    2013-01-01

    Menthol is a common compound in pharmaceutical and commercial products and a popular additive to cigarettes. The molecular targets of menthol remain poorly defined. In this study we show an effect of menthol on the α7 subunit of the nicotinic acetylcholine (nACh) receptor function. Using a two-electrode voltage-clamp technique, menthol was found to reversibly inhibit α7-nACh receptors heterologously expressed in Xenopus oocytes. Inhibition by menthol was not dependent on the membrane potential and did not involve endogenous Ca(2+)-dependent Cl(-) channels, since menthol inhibition remained unchanged by intracellular injection of the Ca(2+) chelator BAPTA and perfusion with Ca(2+)-free bathing solution containing Ba(2+). Furthermore, increasing ACh concentrations did not reverse menthol inhibition and the specific binding of [(125)I] α-bungarotoxin was not attenuated by menthol. Studies of α7- nACh receptors endogenously expressed in neural cells demonstrate that menthol attenuates α7 mediated Ca(2+) transients in the cell body and neurite. In conclusion, our results suggest that menthol inhibits α7-nACh receptors in a noncompetitive manner.

  5. Geranylgeranylacetone inhibits ovarian cancer progression in vitro and in vivo

    International Nuclear Information System (INIS)

    Hashimoto, Kae; Morishige, Ken-ichirou; Sawada, Kenjiro; Ogata, Seiji; Tahara, Masahiro; Shimizu, Shoko; Sakata, Masahiro; Tasaka, Keiichi; Kimura, Tadashi

    2007-01-01

    Geranylgeranylacetone (GGA), an isoprenoid compound, is an anti-ulcer drug developed in Japan. In our previous study, GGA was shown to inhibit ovarian cancer invasion by attenuating Rho activation [K. Hashimoto, K. Morishige, K. Sawada, M. Tahara, S. Shimizu, M. Sakata, K. Tasaka, Y. Murata, Geranylgeranylacetone inhibits lysophosphatidic acid-induced invasion of human ovarian carcinoma cells in vitro. Cancer 103 (2005) 1529-1536.]. In the present study, GGA treatment inhibited ovarian cancer progression in vitro and suppressed the tumor growth and ascites in the in vivo ovarian cancer model. In vitro analysis, treatment of cancer cells by GGA resulted in the inhibition of cancer cell proliferation, the inactivation of Ras, and the suppression of tyrosine phosphorylation of mitogen-activated protein kinase (MAPK). In conclusion, this is the first report that GGA inhibited ovarian cancer progression and the anti-tumor effect by GGA is, at least in part, derived not only from the suppression of Rho activation but also Ras-MAPK activation

  6. AI-2 of Aggregatibacter actinomycetemcomitans Inhibits Candida albicans Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Endang W. Bachtiar

    2014-07-01

    Full Text Available Aggregatibacter actinomycetemcomitans, a Gram-negative bacterium, and Candida albicans, a polymorphic fungus, are both commensals of the oral cavity but both are opportunistic pathogens that can cause oral diseases. A. actinomycetemcomitans produces a quorum-sensing molecule called autoinducer-2 (AI-2, synthesized by LuxS, that plays an important role in expression of virulence factors, in intra- but also in interspecies communication. The aim of this study was to investigate the role of AI-2 based signaling in the interactions between C. albicans and A. actinomycetemcomitans. A. actinomycetemcomitans adhered to C. albicans and inhibited biofilm formation by means of a molecule that was secreted during growth. C. albicans biofilm formation increased significantly when co-cultured with A. actinomycetemcomitans luxS, lacking AI-2 production. Addition of wild-type-derived spent medium or synthetic AI-2 to spent medium of the luxS strain, restored inhibition of C. albicans biofilm formation to wild-type levels. Addition of synthetic AI-2 significantly inhibited hypha formation of C. albicans possibly explaining the inhibition of biofilm formation. AI-2 of A. actinomycetemcomitans is synthesized by LuxS, accumulates during growth and inhibits C. albicans hypha- and biofilm formation. Identifying the molecular mechanisms underlying the interaction between bacteria and fungi may provide important insight into the balance within complex oral microbial communities.

  7. Inhibition of growth of Trichophyton tonsurans by Lactobacillus reuteri.

    Science.gov (United States)

    Guo, J; Mauch, A; Galle, S; Murphy, P; Arendt, E K; Coffey, A

    2011-08-01

    The aims of this study were to identify antifungal lactic acid bacteria (LAB) and characterize their activity against the dermatophyte Trichophyton tonsurans. A total of 165 different LAB were isolated and initially screened for anti-Penicillium expansum activity. Five strains, which exhibited strong inhibitory activity, were then tested against the dermatophyte T. tonsurans DSM12285, where they also caused inhibition as observed by large fungal clearing on agar surface. The strongest inhibition was seen with Lactobacillus reuteri R2. When freeze-dried cell-free supernatant powder from this strain was incorporated in culture medium at concentrations >1%, growth of fungal colony was inhibited. Conidia germination was also inhibited under these conditions as determined by microscopy. The anti-T. tonsurans activity of Lact. reuteri R2 was not affected neither by heat treatment nor by proteolytic treatment using pronase E and proteinase K, indicating that the responsible agent(s) were nonproteinaceous in nature. Lactobacillus reuteri R2 was identified as having strong inhibitory activity against the dermatophyte T. tonsurans DSMZ12285. LAB are naturally associated with many foods and are well recognized for their biopreservative properties. The use of these and/or their products may well provide alternative safe approaches for the inhibition of dermatophytic fungi. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  8. Overdrinking, swallowing inhibition, and regional brain responses prior to swallowing.

    Science.gov (United States)

    Saker, Pascal; Farrell, Michael J; Egan, Gary F; McKinley, Michael J; Denton, Derek A

    2016-10-25

    In humans, drinking replenishes fluid loss and satiates the sensation of thirst that accompanies dehydration. Typically, the volume of water drunk in response to thirst matches the deficit. Exactly how this accurate metering is achieved is unknown; recent evidence implicates swallowing inhibition as a potential factor. Using fMRI, this study investigated whether swallowing inhibition is present after more water has been drunk than is necessary to restore fluid balance within the body. This proposal was tested using ratings of swallowing effort and measuring regional brain responses as participants prepared to swallow small volumes of liquid while they were thirsty and after they had overdrunk. Effort ratings provided unequivocal support for swallowing inhibition, with a threefold increase in effort after overdrinking, whereas addition of 8% (wt/vol) sucrose to water had minimal effect on effort before or after overdrinking. Regional brain responses when participants prepared to swallow showed increases in the motor cortex, prefrontal cortices, posterior parietal cortex, striatum, and thalamus after overdrinking, relative to thirst. Ratings of swallowing effort were correlated with activity in the right prefrontal cortex and pontine regions in the brainstem; no brain regions showed correlated activity with pleasantness ratings. These findings are all consistent with the presence of swallowing inhibition after excess water has been drunk. We conclude that swallowing inhibition is an important mechanism in the overall regulation of fluid intake in humans.

  9. A QSAR Model for Thyroperoxidase Inhibition and Screening ...

    Science.gov (United States)

    Thyroid hormones (THs) are critical modulators of a wide range of biological processes from neurodevelopment to metabolism. Well regulated levels of THs are critical during development and even moderate changes in maternal or fetal TH levels produce irreversible neurological deficits in children. The enzyme thyroperoxidase (TPO) plays a key role in the synthesis of THs. Inhibition of TPO by xenobiotics leads to decreased TH synthesis and, depending on the degree of synthesis inhibition, may result in adverse developmental outcomes. Recently, a high-throughput screening assay for TPO inhibition (AUR-TPO) was developed and used to screen the ToxCast Phase I and II chemicals. In the present study, we used the results from the AUR-TPO screening to develop a Quantitative Structure-Activity Relationship (QSAR) model for TPO inhibition in Leadscope®. The training set consisted of 898 discrete organic chemicals: 134 positive and 764 negative for TPO inhibition. A 10 times two-fold 50% cross-validation of the model was performed, yielding a balanced accuracy of 78.7% within its defined applicability domain. More recently, an additional ~800 chemicals from the US EPA Endocrine Disruption Screening Program (EDSP21) were screened using the AUR-TPO assay. This data was used for external validation of the QSAR model, demonstrating a balanced accuracy of 85.7% within its applicability domain. Overall, the cross- and external validations indicate a model with a high predictiv

  10. In vino veritas? Alcohol, response inhibition and lying.

    Science.gov (United States)

    Suchotzki, Kristina; Crombez, Geert; Debey, Evelyne; van Oorsouw, Kim; Verschuere, Bruno

    2015-01-01

    Despite the widespread belief that alcohol makes the truth come out more easily, we know very little on how alcohol impacts deception. Given that alcohol impairs response inhibition, and that response inhibition may be critically involved in deception, we expected that alcohol intake would hamper lying. In total, 104 volunteers were tested at a science festival, where they had the opportunity to drink alcohol. Stop-Signal Reaction Times (SSRTs) served as operationalization of response inhibition. Differences in error rates and reaction times (RTs) between lying and truth telling served as indicators of the cognitive cost of lying. Higher blood alcohol concentration was related to longer SSRTs, but unrelated to the cognitive costs of lying. This study validates previous laboratory research on alcohol and response inhibition in a realistic drinking environment, yet failed to find an effect of alcohol on lying. Implications of these findings and for the role of response inhibition in lying are discussed. © The Author 2014. Medical Council on Alcohol and Oxford University Press. All rights reserved.

  11. Thyroid peroxidase activity is inhibited by amino acids

    Directory of Open Access Journals (Sweden)

    D.P. Carvalho

    2000-03-01

    Full Text Available Normal in vitro thyroid peroxidase (TPO iodide oxidation activity was completely inhibited by a hydrolyzed TPO preparation (0.15 mg/ml or hydrolyzed bovine serum albumin (BSA, 0.2 mg/ml. A pancreatic hydrolysate of casein (trypticase peptone, 0.1 mg/ml and some amino acids (cysteine, tryptophan and methionine, 50 µM each also inhibited the TPO iodide oxidation reaction completely, whereas casamino acids (0.1 mg/ml, and tyrosine, phenylalanine and histidine (50 µM each inhibited the TPO reaction by 54% or less. A pancreatic digest of gelatin (0.1 mg/ml or any other amino acid (50 µM tested did not significantly decrease TPO activity. The amino acids that impair iodide oxidation also inhibit the TPO albumin iodination activity. The inhibitory amino acids contain side chains with either sulfur atoms (cysteine and methionine or aromatic rings (tyrosine, tryptophan, histidine and phenylalanine. Among the amino acids tested, only cysteine affected the TPO guaiacol oxidation reaction, producing a transient inhibition at 25 or 50 µM. The iodide oxidation inhibitory activity of cysteine, methionine and tryptophan was reversed by increasing iodide concentrations from 12 to 18 mM, while no such effect was observed when the cofactor (H2O2 concentration was increased. The inhibitory substances might interfere with the enzyme activity by competing with its normal substrates for their binding sites, binding to the free substrates or reducing their oxidized form.

  12. Recruitment of Perisomatic Inhibition during Spontaneous Hippocampal Activity In Vitro.

    Directory of Open Access Journals (Sweden)

    Anna Beyeler

    Full Text Available It was recently shown that perisomatic GABAergic inhibitory postsynaptic potentials (IPSPs originating from basket and chandelier cells can be recorded as population IPSPs from the hippocampal pyramidal layer using extracellular electrodes (eIPSPs. Taking advantage of this approach, we have investigated the recruitment of perisomatic inhibition during spontaneous hippocampal activity in vitro. Combining intracellular and extracellular recordings from pyramidal cells and interneurons, we confirm that inhibitory signals generated by basket cells can be recorded extracellularly, but our results suggest that, during spontaneous activity, eIPSPs are mostly confined to the CA3 rather than CA1 region. CA3 eIPSPs produced the powerful time-locked inhibition of multi-unit activity expected from perisomatic inhibition. Analysis of the temporal dynamics of spike discharges relative to eIPSPs suggests significant but moderate recruitment of excitatory and inhibitory neurons within the CA3 network on a 10 ms time scale, within which neurons recruit each other through recurrent collaterals and trigger powerful feedback inhibition. Such quantified parameters of neuronal interactions in the hippocampal network may serve as a basis for future characterisation of pathological conditions potentially affecting the interactions between excitation and inhibition in this circuit.

  13. Inhibition of cancer cell growth by ruthenium complexes.

    Science.gov (United States)

    Iida, Joji; Bell-Loncella, Elisabeth T; Purazo, Marc L; Lu, Yifeng; Dorchak, Jesse; Clancy, Rebecca; Slavik, Julianna; Cutler, Mary Lou; Shriver, Craig D

    2016-02-12

    Previous studies suggest that certain transition metal complexes, such as cisplatin, are efficacious for treating various cancer types, including ovarian, lung, and breast. In order to further evaluate ruthenium (Ru) complexes as potential anti-cancer agents, we synthesized and evaluated Ru-arene complexes. Two complexes with the general formula [Ru (η (6)-p-cym) (N-N) Cl](+) were tested for their abilities to inhibit cancer cells. The complex with o-phenylenediamine as the N-N ligand (o-PDA) significantly inhibited growth of breast (MDA-MB-231, MCF-7, SKBR-3, and SUM149), lymphoma (Raji), melanoma (Bowes), and osteosarcoma (HT1080); however, the complex with o-benzoquinonediimine (o-BQDI) was ineffective except for SUM149. In contrast, o-PDA failed to inhibit growth of human breast epithelial cells, MCF-10A. Treatment of MDA-MBA-231 cells with o-PDA resulted in a significant reduction of productions of PDGF-AA, GM-CSF, and VEGF-A proteins at the transcriptional levels. Finally, we demonstrated that o-PDA synergistically inhibited MDA-MB-231 cell growth with cyclophosphamide but not doxorubicin or paclitaxel. These results suggest that Ru-arene complexes are promising anti-cancer drugs that inhibit progression and metastasis by blocking multiple processes for breast and other types of cancer.

  14. Dual effect of chloramphenicol peptides on ribosome inhibition.

    Science.gov (United States)

    Bougas, Anthony; Vlachogiannis, Ioannis A; Gatos, Dimitrios; Arenz, Stefan; Dinos, George P

    2017-05-01

    Chloramphenicol peptides were recently established as useful tools for probing nascent polypeptide chain interaction with the ribosome, either biochemically, or structurally. Here, we present a new 10mer chloramphenicol peptide, which exerts a dual inhibition effect on the ribosome function affecting two distinct areas of the ribosome, namely the peptidyl transferase center and the polypeptide exit tunnel. According to our data, the chloramphenicol peptide bound on the chloramphenicol binding site inhibits the formation of both acetyl-phenylalanine-puromycin and acetyl-lysine-puromycin, showing, however, a decreased peptidyl transferase inhibition compared to chloramphenicol-mediated inhibition per se. Additionally, we found that the same compound is a strong inhibitor of green fluorescent protein synthesis in a coupled in vitro transcription-translation assay as well as a potent inhibitor of lysine polymerization in a poly(A)-programmed ribosome, showing that an additional inhibitory effect may exist. Since chemical protection data supported the interaction of the antibiotic with bases A2058 and A2059 near the entrance of the tunnel, we concluded that the extra inhibition effect on the synthesis of longer peptides is coming from interactions of the peptide moiety of the drug with residues comprising the ribosomal tunnel, and by filling up the tunnel and blocking nascent chain progression through the restricted tunnel. Therefore, the dual interaction of the chloramphenicol peptide with the ribosome increases its inhibitory effect and opens a new window for improving the antimicrobial potency of classical antibiotics or designing new ones.

  15. IGF-1 receptor inhibition by picropodophyllin in medulloblastoma

    International Nuclear Information System (INIS)

    Ohshima-Hosoyama, Sachiko; Hosoyama, Tohru; Nelon, Laura D.; Keller, Charles

    2010-01-01

    Research highlights: → Igf1r is overexpressed and activated in a Sonic Hedgehog driven model of medulloblastoma. → Picropodophyllin targets and abrogates IGF signaling in medulloblastoma. → Picropodophyllin inhibits medulloblastoma tumor cell growth by induction of apoptosis. -- Abstract: The insulin-like growth factor-1 receptor (Igf1r) is a multifunctional membrane-associated tyrosine kinase associated with regulation of transformation, proliferation, differentiation and apoptosis. Increased IGF pathway activity has been reported in human and murine medulloblastoma. Tumors from our genetically-engineered medulloblastoma mouse model over-express Igf1r, and thus this mouse model is a good platform with which to study the role of Igf1r in tumor progression. We hypothesize that inhibition of IGF pathway in medulloblastoma can slow or inhibit tumor growth and metastasis. To test our hypothesis, we tested the role of IGF in tumor growth in vitro by treatment with the tyrosine kinase small molecule inhibitor, picropodophyllin (PPP), which strongly inhibits the IGF pathway. Our results demonstrate that PPP-mediated downregulation of the IGF pathway inhibits mouse tumor cell growth and induces apoptotic cell death in vitro in primary medulloblastoma cultures that are most reflective of tumor cell behavior in vivo.

  16. Combined PDGFR and HDAC Inhibition Overcomes PTEN Disruption in Chordoma.

    Directory of Open Access Journals (Sweden)

    Dae-Hee Lee

    Full Text Available The majority of chordomas show activation of the platelet-derived growth factor receptor (PDGFR. Based on in vitro intertumoral variation in response to recombinant PDGF protein and PDGFR inhibition, and variable tumor response to imatinib, we hypothesized that chordomas resistant to PDGFR inhibition may possess downstream activation of the pathway.Molecular profiling was performed on 23 consecutive chordoma primary tissue specimens. Primary cultures established from 20 of the 23 specimens, and chordoma cell lines, UCH-1 and UCH-2, were used for in vitro experiments.Loss of heterozygosity (LOH at the phosphatase and tensin homolog (PTEN locus was observed in 6 specimens (26%. PTEN disruption statistically correlated with increased Ki-67 proliferation index, an established marker of poor outcome for chordoma. Compared to wild type, PTEN deficient chordomas displayed increased proliferative rate, and responded less favorably to PDGFR inhibition. PTEN gene restoration abrogated this growth advantage. Chordomas are characterized by intratumoral hypoxia and local invasion, and histone deacetylase (HDAC inhibitors are capable of attenuating both hypoxic signaling and cell migration. The combination of PDGFR and HDAC inhibition effectively disrupted growth and invasion of PTEN deficient chordoma cells.Loss of heterozygosity of the PTEN gene seen in a subset of chordomas is associated with aggressive in vitro behavior and strongly correlates with increased Ki-67 proliferative index. Combined inhibition of PDGFR and HDAC attenuates proliferation and invasion in chordoma cells deficient for PTEN.

  17. Combined PDGFR and HDAC Inhibition Overcomes PTEN Disruption in Chordoma.

    Science.gov (United States)

    Lee, Dae-Hee; Zhang, Ying; Kassam, Amin B; Park, Myung-Jin; Gardner, Paul; Prevedello, Daniel; Henry, Stephanie; Horbinski, Craig; Beumer, Jan H; Tawbi, Hussein; Williams, Brian J; Shaffrey, Mark E; Egorin, Merrill J; Abounader, Roger; Park, Deric M

    2015-01-01

    The majority of chordomas show activation of the platelet-derived growth factor receptor (PDGFR). Based on in vitro intertumoral variation in response to recombinant PDGF protein and PDGFR inhibition, and variable tumor response to imatinib, we hypothesized that chordomas resistant to PDGFR inhibition may possess downstream activation of the pathway. Molecular profiling was performed on 23 consecutive chordoma primary tissue specimens. Primary cultures established from 20 of the 23 specimens, and chordoma cell lines, UCH-1 and UCH-2, were used for in vitro experiments. Loss of heterozygosity (LOH) at the phosphatase and tensin homolog (PTEN) locus was observed in 6 specimens (26%). PTEN disruption statistically correlated with increased Ki-67 proliferation index, an established marker of poor outcome for chordoma. Compared to wild type, PTEN deficient chordomas displayed increased proliferative rate, and responded less favorably to PDGFR inhibition. PTEN gene restoration abrogated this growth advantage. Chordomas are characterized by intratumoral hypoxia and local invasion, and histone deacetylase (HDAC) inhibitors are capable of attenuating both hypoxic signaling and cell migration. The combination of PDGFR and HDAC inhibition effectively disrupted growth and invasion of PTEN deficient chordoma cells. Loss of heterozygosity of the PTEN gene seen in a subset of chordomas is associated with aggressive in vitro behavior and strongly correlates with increased Ki-67 proliferative index. Combined inhibition of PDGFR and HDAC attenuates proliferation and invasion in chordoma cells deficient for PTEN.

  18. Thiazolidinediones inhibit REG Iα gene transcription in gastrointestinal cancer cells

    International Nuclear Information System (INIS)

    Yamauchi, Akiyo; Takahashi, Iwao; Takasawa, Shin; Nata, Koji; Noguchi, Naoya; Ikeda, Takayuki; Yoshikawa, Takeo; Shervani, Nausheen J.; Suzuki, Iwao; Uruno, Akira; Unno, Michiaki; Okamoto, Hiroshi; Sugawara, Akira

    2009-01-01

    REG (Regenerating gene) Iα protein functions as a growth factor for gastrointestinal cancer cells, and its mRNA expression is strongly associated with a poor prognosis in gastrointestinal cancer patients. We here demonstrated that PPARγ-agonist thiazolidinediones (TZDs) inhibited cell proliferation and REG Iα protein/mRNA expression in gastrointestinal cancer cells. TZDs inhibited the REG Iα gene promoter activity, via its cis-acting element which lacked PPAR response element and could not bind to PPARγ, in PPARγ-expressing gastrointestinal cancer cells. The inhibition was reversed by co-treatment with a specific PPARγ-antagonist GW9662. Although TZDs did not inhibit the REG Iα gene promoter activity in PPARγ-non-expressing cells, PPARγ overexpression in the cells recovered their inhibitory effect. Taken together, TZDs inhibit REG Iα gene transcription through a PPARγ-dependent pathway. The TZD-induced REG Iα mRNA reduction was abolished by cycloheximide, indicating the necessity of novel protein(s) synthesis. TZDs may therefore be a candidate for novel anti-cancer drugs for patients with gastrointestinal cancer expressing both REG Iα and PPARγ.

  19. IMATINIB MESYLATE INHIBITS FIBROGENESIS IN ASBESTOS-INDUCED INTERSTITIAL PNEUMONIA

    Science.gov (United States)

    Vuorinen, Kirsi; Gao, Fei; Oury, Tim D.; Kinnula, Vuokko L.; Myllärniemi, Marjukka

    2009-01-01

    Profibrogeneic cytokines contribute to the accumulation of myofibroblasts in the lung interstitium in idiopathic pulmonary fibrosis (IPF). Imatinib mesylate, a tyrosine kinase inhibitor specific for Abl, platelet-derived growth factor receptor (PDGFR) and c-Kit tyrosine kinases, has been shown to inhibit fibrosis and profibrotic signaling in mouse models of inflammation-mediated lung reactions. The authors tested imatinib mesylate in vivo in a mouse model of crocidolite asbestos-induced progressive fibrosis. The ability of imatinib mesylate to inhibit profibrogeneic cytokine-induced human pulmonary fibroblast migration was tested in vitro and the expression of its target protein tyrosine kinases was assessed with immunofluorescence. In vivo, 10 mg/kg/day imatinib mesylate inhibited histological parenchymal fibrosis and led to a decrease in collagen deposition, but had no significant effect on asbestos-induced neutrophilia. However, 50 mg/kg/day imatinib mesylate did not inhibit collagen deposition. In vitro, IPF fibroblasts expressed Abl, PDGFR-α, PDGF-β, but not c-Kit, and 1 μM imatinib mesylate inhibited profibrogeneic cytokine-induced IPF fibroblast migration. These results suggest that imatinib mesylate is a potential and specific inhibitor of fibroblast accumulation in asbestos-induced pulmonary fibrosis. PMID:17849262

  20. Two mechanisms of oral malodor inhibition by zinc ions

    Directory of Open Access Journals (Sweden)

    Nao Suzuki

    2018-01-01

    Full Text Available Abstract Objectives The aim of this study was to reveal the mechanisms by which zinc ions inhibit oral malodor. Material and Methods The direct binding of zinc ions to gaseous hydrogen sulfide (H2S was assessed in comparison with other metal ions. Nine metal chlorides and six metal acetates were examined. To understand the strength of H2S volatilization inhibition, the minimum concentration needed to inhibit H2S volatilization was determined using serial dilution methods. Subsequently, the inhibitory activities of zinc ions on the growth of six oral bacterial strains related to volatile sulfur compound (VSC production and three strains not related to VSC production were evaluated. Results Aqueous solutions of ZnCl2, CdCl2, CuCl2, (CH3COO2Zn, (CH3COO2Cd, (CH3COO2Cu, and CH3COOAg inhibited H2S volatilization almost entirely. The strengths of H2S volatilization inhibition were in the order Ag+ > Cd2+ > Cu2+ > Zn2+. The effect of zinc ions on the growth of oral bacteria was strain-dependent. Fusobacterium nucleatum ATCC 25586 was the most sensitive, as it was suppressed by medium containing 0.001% zinc ions. Conclusions Zinc ions have an inhibitory effect on oral malodor involving the two mechanisms of direct binding with gaseous H2S and suppressing the growth of VSC-producing oral bacteria.

  1. Menthol binding and inhibition of α7-nicotinic acetylcholine receptors.

    Directory of Open Access Journals (Sweden)

    Abrar Ashoor

    Full Text Available Menthol is a common compound in pharmaceutical and commercial products and a popular additive to cigarettes. The molecular targets of menthol remain poorly defined. In this study we show an effect of menthol on the α7 subunit of the nicotinic acetylcholine (nACh receptor function. Using a two-electrode voltage-clamp technique, menthol was found to reversibly inhibit α7-nACh receptors heterologously expressed in Xenopus oocytes. Inhibition by menthol was not dependent on the membrane potential and did not involve endogenous Ca(2+-dependent Cl(- channels, since menthol inhibition remained unchanged by intracellular injection of the Ca(2+ chelator BAPTA and perfusion with Ca(2+-free bathing solution containing Ba(2+. Furthermore, increasing ACh concentrations did not reverse menthol inhibition and the specific binding of [(125I] α-bungarotoxin was not attenuated by menthol. Studies of α7- nACh receptors endogenously expressed in neural cells demonstrate that menthol attenuates α7 mediated Ca(2+ transients in the cell body and neurite. In conclusion, our results suggest that menthol inhibits α7-nACh receptors in a noncompetitive manner.

  2. Depletion of Pokemon gene inhibits hepatocellular carcinoma cell growth through inhibition of H-ras.

    Science.gov (United States)

    Zhang, Quan-Le; Tian, De-An; Xu, Xiang-Jiang

    2011-01-01

    Pokemon is a transcription repressor which plays a critical role in cell transformation and malignancy. However, little is known about its effect on the development and progression of hepatocellular carcinoma (HCC). The aim of this study was to investigate the expression of Pokemon in human HCC tissues and the biological behavior of Pokemon in HCC cells in which it is overexpressed. We also explored the expression of potential downstream cofactors of Pokemon. Reverse transcription polymerase chain reaction and Western blot analysis were used to investigate the expression of Pokemon in tissues of 30 HCC patients. We then examined cell proliferation or apoptosis and β-catenin or H-ras expression in Pokemon-depleted HepG(2) cells using DNA vector-based RNA interference technology. Pokemon was markedly expressed in 22/30 (73.3%) HCC tissues, with expression levels higher than in adjacent normal liver tissues (p Pokemon inhibited proliferation of HepG(2) or induced apoptosis. Also, H-ras expression decreased to a large extent. Pokemon exerts its oncogenic activity in the development of HCC by promoting cancer cell growth and reducing apoptosis, and the effect may be mediated by H-ras. Copyright © 2011 S. Karger AG, Basel.

  3. Astaxanthin inhibits gemcitabine-resistant human pancreatic cancer progression through EMT inhibition and gemcitabine resensitization.

    Science.gov (United States)

    Yan, Tao; Li, Hai-Ying; Wu, Jian-Song; Niu, Qiang; Duan, Wei-Hong; Han, Qing-Zeng; Ji, Wang-Ming; Zhang, Tao; Lv, Wei

    2017-11-01

    Pancreatic cancer rapidly acquires resistance to chemotherapy resulting in its being difficult to treat. Gemcitabine is the current clinical chemotherapy strategy; however, owing to gemcitabine resistance, it is only able to prolong the life of patients with pancreatic cancer for a limited number of months. Understanding the underlying molecular mechanisms of gemcitabine resistance and selecting a suitable combination of agents for the treatment of pancreatic cancer is required. Astaxanthin (ASX) is able to resensitize gemcitabine-resistant human pancreatic cancer cells (GR-HPCCs) to gemcitabine. ASX was identified to upregulate human equilibrative nucleoside transporter 1 (hENT1) and downregulate ribonucleoside diphosphate reductase (RRM) 1 and 2 to enhance gemcitabine-induced cell death in GR-HPCCs treated with gemcitabine, and also downregulates TWIST1 and ZEB1 to inhibit the gemcitabine-induced epithelial-mesenchymal transition (EMT) phenotype in GR-HPCCs and to mediate hENT1, RRM1 and RRM2. Furthermore, ASX acts through the hypoxia-inducible factor 1α/signal transducer and activator of transcription 3 signaling pathway to mediate TWIST1, ZEB1, hENT1, RRM1 and RRM2, regulating the gemcitabine-induced EMT phenotype and gemcitabine-induced cell death. Co-treatment with ASX and gemcitabine in a tumor xenograft model induced by GR-HPCCs supported the in vitro results. The results of the present study provide a novel therapeutic strategy for the treatment of gemcitabine-resistant pancreatic cancer.

  4. Antisense inhibition of hyaluronan synthase-2 in human osteosarcoma cells inhibits hyaluronan retention and tumorigenicity

    International Nuclear Information System (INIS)

    Nishida, Yoshihiro; Knudson, Warren; Knudson, Cheryl B.; Ishiguro, Naoki

    2005-01-01

    Osteosarcoma is a common malignant bone tumor associated with childhood and adolescence. The results of numerous studies have suggested that hyaluronan plays an important role in regulating the aggressive behavior of various types of cancer cells. However, no studies have addressed hyaluronan with respect to osteosarcomas. In this investigation, the mRNA expression copy number of three mammalian hyaluronan synthases (HAS) was determined using competitive RT-PCR in the osteoblastic osteosarcoma cell line, MG-63. MG-63 are highly malignant osteosarcoma cells with an abundant hyaluronan-rich matrix. The results demonstrated that HAS-2 is the predominant HAS in MG-63. Accumulation of intracellular hyaluronan increased in association with the proliferative phase of these cells. The selective inhibition of HAS-2 mRNA in MG-63 cells by antisense phosphorothioate oligonucleotides resulted in reduced hyaluronan accumulation by these cells. As expected, the reduction in hyaluronan disrupted the assembly of cell-associated matrices. However, of most interest, coincident with the reduction in hyaluronan, there was a substantial decrease in cell proliferation, a decrease in cell motility and a decrease in cell invasiveness. These data suggest that hyaluronan synthesized by HAS-2 in MG-63 plays a crucial role in osteosarcoma cell proliferation, motility, and invasion

  5. Somatosensory lateral inhibition processes modulate motor response inhibition - an EEG source localization study.

    Science.gov (United States)

    Friedrich, Julia; Mückschel, Moritz; Beste, Christian

    2017-06-30

    Motor inhibitory control is a central executive function, but only recently the importance of perceptual mechanisms for these processes has been focused. It is elusive whether basic mechanisms governing sensory perception affect motor inhibitory control. We examine whether sensory lateral inhibition (LI) processes modulate motor inhibitory control using a system neurophysiological approach combining EEG signal decomposition with source localization methods in a somatosensory GO/NOGO task. The results show that inter-individual variations in the strength of LI effects predominantly affect processes when information needs to be integrated between cerebral hemispheres. If information needs to be integrated between hemispheres, strong sensory suppression will lead to more impulsive errors. Importantly, the neurophysiological data suggest that not purely perceptual or motor processes are affected. Rather, LI affects the response selection level and modulates processes of stimulus categorization. This is associated with activity modulations in the posterior parietal cortex. The results suggest that when sensory suppression is high and when information needs to be integrated across hemispheres, these processes are less efficient, which likely leads to worse motor inhibitory control. The results show how basis principles modulating perceptual processes affect subsequent motor inhibitory control processes.

  6. Vanadate-induced inhibition of renin secretion is unrelated to inhibition Na,K-ATPase activity

    Energy Technology Data Exchange (ETDEWEB)

    Churchill, P.C.; Rossi, N.F.; Churchill, M.C.; Ellis, V.R. (Wayne State Univ. School of Medicine, Detroit, MI (USA))

    1990-01-01

    There is evidence that three inhibitors of Na,K-ATPase activity-ouabain, K-free extracellular fluid, and vanadate--inhibit renin secretion by increasing Ca{sup 2+} concentration in juxtaglomerular cells, but in the case of vanadate, it is uncertain whether the increase in Ca{sup 2+} is due to a decrease in Ca{sup 2+} efflux or to an increase in Ca{sup 2+} influx through potential operated Ca channels. In the present experiments, the rat renal cortical slice preparation was used to compare and contrast the effects of ouabain, of K-free fluid, and of vanadate on renin secretion, in the absence and presence of methoxyverapamil, A Ca channel blocker. Basal renin secretory rate averaged 7.7 {plus minus} 0.3 GU/g/60 min, and secretory rate was reduced to nearly zero by 1 mM ouabain, by K-free fluid, by 0.5 mM vanadate, and by K-depolarization. Although 0.5 {mu}M methoxyverapamil completely blocked the inhibitory effect of K-depolarization, it failed to antagonize the inhibitory effects of ouabain, of K-free fluid, and of vanadate.

  7. Inhibition of 5-Lipoxygenase Pathway Attenuates Acute Liver Failure by Inhibiting Macrophage Activation

    Directory of Open Access Journals (Sweden)

    Lu Li

    2014-01-01

    Full Text Available This study aimed to investigate the role of 5-lipoxygenase (5-LO in acute liver failure (ALF and changes in macrophage activation by blocking it. ALF was induced in rats by administration of D-galactosamine (D-GalN/lipopolysaccharide (LPS. Rats were injected intraperitoneally with AA-861 (a specific 5-LO inhibitor, 24 hr before D-GalN/LPS administration. After D-GalN/LPS injection, the liver tissue was collected for assessment of histology, macrophage microstructure, macrophage counts, 5-LO mRNA formation, protein expression, and concentration of leukotrienes. Serum was collected for detecting alanine aminotransferase (ALT, aspartate transaminase (AST, total bilirubin (Tbil, and tumor necrosis factor- (TNF-α. Twenty-four hours after injection, compared with controls, ALF rats were characterized by widespread hepatocyte necrosis and elevated ALT, AST, and Tbil, and 5-LO protein expression reached a peak. Liver leukotriene B4 was also significantly elevated. However, 5-LO mRNA reached a peak 8 hr after D-GalN/LPS injection. Simultaneously, the microstructure of macrophages was changed most significantly and macrophages counts were increased significantly. Moreover, serum TNF-α was also elevated. By contrast, AA-861 pretreatment significantly decreased liver necrosis as well as all of the parameters compared with the rats without pretreatment. Macrophages, via the 5-LO pathway, play a critical role in ALF, and 5-LO inhibitor significantly alleviates ALF, possibly related to macrophage inhibition.

  8. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    Energy Technology Data Exchange (ETDEWEB)

    Hannon, Patrick R., E-mail: phannon2@illinois.edu; Brannick, Katherine E., E-mail: kbran@illinois.edu; Wang, Wei, E-mail: Wei.Wang2@covance.com; Gupta, Rupesh K., E-mail: drrupesh@yahoo.com; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2015-04-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP

  9. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    International Nuclear Information System (INIS)

    Hannon, Patrick R.; Brannick, Katherine E.; Wang, Wei; Gupta, Rupesh K.; Flaws, Jodi A.

    2015-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP

  10. Repellents inhibit P450 enzymes in Stegomyia (Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Gloria Isabel Jaramillo Ramirez

    Full Text Available The primary defence against mosquitoes and other disease vectors is often the application of a repellent. Despite their common use, the mechanism(s underlying the activity of repellents is not fully understood, with even the mode of action of DEET having been reported to be via different mechanisms; e.g. interference with olfactory receptor neurones or actively detected by olfactory receptor neurones on the antennae or maxillary palps. In this study, we discuss a novel mechanism for repellence, one of P450 inhibition. Thirteen essential oil extracts from Colombian plants were assayed for potency as P450 inhibitors, using a kinetic fluorometric assay, and for repellency using a modified World Health Organisation Pesticide Evaluations Scheme (WHOPES arm-in cage assay with Stegomyia (Aedes aegypti mosquitoes. Bootstrap analysis on the inhibition analysis revealed a significant correlation between P450-inhibition and repellent activity of the oils.

  11. Aedes aegypti D7 Saliva Protein Inhibits Dengue Virus Infection.

    Directory of Open Access Journals (Sweden)

    Michael J Conway

    2016-09-01

    Full Text Available Aedes aegypti is the primary vector of several medically relevant arboviruses including dengue virus (DENV types 1-4. Ae. aegypti transmits DENV by inoculating virus-infected saliva into host skin during probing and feeding. Ae. aegypti saliva contains over one hundred unique proteins and these proteins have diverse functions, including facilitating blood feeding. Previously, we showed that Ae. aegypti salivary gland extracts (SGEs enhanced dissemination of DENV to draining lymph nodes. In contrast, HPLC-fractionation revealed that some SGE components inhibited infection. Here, we show that D7 proteins are enriched in HPLC fractions that are inhibitory to DENV infection, and that recombinant D7 protein can inhibit DENV infection in vitro and in vivo. Further, binding assays indicate that D7 protein can directly interact with DENV virions and recombinant DENV envelope protein. These data reveal a novel role for D7 proteins, which inhibits arbovirus transmission to vertebrates through a direct interaction with virions.

  12. BACE inhibition-dependent repair of Alzheimer's pathophysiology.

    Science.gov (United States)

    Keskin, Aylin D; Kekuš, Maja; Adelsberger, Helmuth; Neumann, Ulf; Shimshek, Derya R; Song, Beomjong; Zott, Benedikt; Peng, Tingying; Förstl, Hans; Staufenbiel, Matthias; Nelken, Israel; Sakmann, Bert; Konnerth, Arthur; Busche, Marc Aurel

    2017-08-08

    Amyloid-β (Aβ) is thought to play an essential pathogenic role in Alzheimer´s disease (AD). A key enzyme involved in the generation of Aβ is the β-secretase BACE, for which powerful inhibitors have been developed and are currently in use in human clinical trials. However, although BACE inhibition can reduce cerebral Aβ levels, whether it also can ameliorate neural circuit and memory impairments remains unclear. Using histochemistry, in vivo Ca 2+ imaging, and behavioral analyses in a mouse model of AD, we demonstrate that along with reducing prefibrillary Aβ surrounding plaques, the inhibition of BACE activity can rescue neuronal hyperactivity, impaired long-range circuit function, and memory defects. The functional neuronal impairments reappeared after infusion of soluble Aβ, mechanistically linking Aβ pathology to neuronal and cognitive dysfunction. These data highlight the potential benefits of BACE inhibition for the effective treatment of a wide range of AD-like pathophysiological and cognitive impairments.

  13. Aluminum Trichloride Inhibits the Rat Osteoblasts Mineralization In Vitro.

    Science.gov (United States)

    Song, Miao; Huo, Hui; Cao, Zheng; Han, Yanfei; Gao, Li

    2017-01-01

    Aluminum (Al) is an accumulative toxic metal. Excessive Al accumulation inhibits osteoblasts mineralization and induces osteoporosis. However, the inhibition mechanism of Al on the mineralization is not fully understood. Thus, in this study, the rat osteoblasts were cultured and exposed to 0 mmol L -1 (control group, CG) and 0.52 mmol L -1 aluminum trichloride (AlCl 3 , treatment group, TG) for 7, 14, and 21 days, respectively. We found that mineralized matrix nodules, the activity of bone alkaline phosphatase, the concentration of extracellular calcium, the mRNA expression of type-I collagen, the mRNA and protein expressions of osteopontin, osteocalcin, and bone sialoprotein were all decreased, while the concentration of extracellular phosphorus was increased in TG compared with CG with time prolonged. Taken together, these results indicated that AlCl 3 inhibited osteoblasts mineralization in vitro.

  14. Partial inhibition of polysomal ribosomes of Escherichia coli by streptomycin.

    Science.gov (United States)

    Wallace, B J; Tai, P C; Herzog, E L; Davis, B D

    1973-04-01

    With purified initiation-free polysomes of E. coli, whether endogenous or formed in vitro on phage R17 RNA, streptomycin causes partial inhibition of chain elongation. The degree of inhibition is constant over a broad range of streptomycin concentration and decreases markedly with increasing Mg(++) concentration. Hence, streptomycin evidently complexes readily with polysomal ribosomes, causing a partial block in chain elongation. Streptomycin has already been shown to cause a complete block of chain elongation by free ribosomes forming initiation complexes in its presence. The production of a different effect on polysomal ribosomes explains how streptomycin can exert two mutually exclusive effects in cells: phenotypic suppression at low concentrations and irreversible inhibition of protein synthesis at higher concentrations. It also becomes possible to understand why killing by streptomycin is antagonized by agents (such as chloramphenicol) that cause a stable blockade of the ribosomes in polysomes.

  15. Physiological Markers of Motor Inhibition during Human Behavior.

    Science.gov (United States)

    Duque, Julie; Greenhouse, Ian; Labruna, Ludovica; Ivry, Richard B

    2017-04-01

    Transcranial magnetic stimulation (TMS) studies in humans have shown that many behaviors engage processes that suppress excitability within the corticospinal tract. Inhibition of the motor output pathway has been extensively studied in the context of action stopping, where a planned movement needs to be abruptly aborted. Recent TMS work has also revealed markers of motor inhibition during the preparation of movement. Here, we review the evidence for motor inhibition during action stopping and action preparation, focusing on studies that have used TMS to monitor changes in the excitability of the corticospinal pathway. We discuss how these physiological results have motivated theoretical models of how the brain selects actions, regulates movement initiation and execution, and switches from one state to another. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Inhibition of placenta growth factor with TB-403

    DEFF Research Database (Denmark)

    Nielsen, Dorte Lisbet; Sengeløv, Lisa

    2012-01-01

    targeting angiogenesis. AREAS COVERED: The data are obtained by searching in the PubMed database. The search terms used included antiangiogenic therapy, TB-403 (RO5323441), placenta growth factor (PlGF) and VEGFR-1 (Flt-1). We review preclinical data concerning the function and inhibition of PlGF...... and summarize data on expression of PlGF in cancer patients. Data from early-phase clinical trials of TB-403 (RO5323441), a monoclonal antibody inhibiting PlGF, are discussed. Future development strategies, therapeutic potentials and limitations of TB-403 are further evaluated. EXPERT OPINION: There are some...... conflicting data on the function of PlGF and the importance of its role in primary tumor growth. Data from some preclinical models of PlGF inhibition and early-phase clinical trials with TB-403 are, however, promising, although the true potential of the drug is yet to be determined. Further clinical...

  17. Gold Nanoparticles and Microwave Irradiation Inhibit Beta-Amyloid Amyloidogenesis

    Directory of Open Access Journals (Sweden)

    Bastus Neus

    2008-01-01

    Full Text Available Abstract Peptide-Gold nanoparticles selectively attached to β-amyloid protein (Aβ amyloidogenic aggregates were irradiated with microwave. This treatment produces dramatic effects on the Aβ aggregates, inhibiting both the amyloidogenesis and the restoration of the amyloidogenic potential. This novel approach offers a new strategy to inhibit, locally and remotely, the amyloidogenic process, which could have application in Alzheimer’s disease therapy. We have studied the irradiation effect on the amyloidogenic process in the presence of conjugates peptide-nanoparticle by transmission electronic microscopy observations and by Thioflavine T assays to quantify the amount of fibrils in suspension. The amyloidogenic aggregates rather than the amyloid fibrils seem to be better targets for the treatment of the disease. Our results could contribute to the development of a new therapeutic strategy to inhibit the amyloidogenic process in Alzheimer’s disease.

  18. Siderocalin inhibits the intracellular replication of Mycobacterium tuberculosis in macrophages

    DEFF Research Database (Denmark)

    Johnson, Erin E; Srikanth, Chittur V; Sandgren, Andreas

    2010-01-01

    that siderocalin expression is upregulated following M.tb infection of mouse macrophage cell lines and primary murine alveolar macrophages. Furthermore, siderocalin added exogenously as a recombinant protein or overexpressed in the RAW264.7 macrophage cell line inhibited the intracellular growth of the pathogen......Siderocalin is a secreted protein that binds to siderophores to prevent bacterial iron acquisition. While it has been shown to inhibit the growth of Mycobacterium tuberculosis (M.tb) in extracellular cultures, its effect on this pathogen within macrophages is not clear. Here, we show....... A variant form of siderocalin, which is expressed only in the macrophage cytosol, inhibited intracellular M.tb growth as effectively as the normal, secreted form, an observation that provides mechanistic insight into how siderocalin might influence iron acquisition by the bacteria in the phagosome. Our...

  19. Transcriptome dynamics of the microRNA inhibition response

    DEFF Research Database (Denmark)

    Wen, Jiayu; Leucci, Elenora; Vendramin, Roberto

    2015-01-01

    We report a high-resolution time series study of transcriptome dynamics following antimiR-mediated inhibition of miR-9 in a Hodgkin lymphoma cell-line-the first such dynamic study of the microRNA inhibition response-revealing both general and specific aspects of the physiological response. We show...... miR-9 inhibition inducing a multiphasic transcriptome response, with a direct target perturbation before 4 h, earlier than previously reported, amplified by a downstream peak at ∼32 h consistent with an indirect response due to secondary coherent regulation. Predictive modelling indicates a major...... role for miR-9 in post-transcriptional control of RNA processing and RNA binding protein regulation. Cluster analysis identifies multiple co-regulated gene regulatory modules. Functionally, we observe a shift over time from mRNA processing at early time points to translation at later time points. We...

  20. K(+) starvation inhibits water-stress-induced stomatal closure.

    Science.gov (United States)

    Benlloch-González, María; Arquero, Octavio; Fournier, José María; Barranco, Diego; Benlloch, Manuel

    2008-04-18

    The effect of potassium starvation on stomatal conductance was studied in olive trees and sunflower plants, two major crops with greatly differing botanical characteristics. In both species, K(+) starvation inhibited water-stress-induced stomatal closure. In olive trees, potassium starvation favoured stomatal conductance and transpiration, as well as inhibiting shoot growth, in the three cultivars studied: 'Lechín de Granada', 'Arbequina' and 'Chetoui'. However, 'Lechín de Granada' - generally considered more drought-tolerant than 'Arbequina' and 'Chetoui' - proved less susceptible to potassium starvation. Results for olive trees also suggest genetic variability in olive cultivars in relation to potassium requirements for stem growth and the regulation of water transpiration. The results obtained suggest that inhibition of the stomatal closure mechanism produced by moderate potassium starvation is a widespread plant physiological disorder, and may be the cause of tissue dehydration in many water-stressed crops.

  1. Molecular basis of cyclooxygenase enzymes (COXs) selective inhibition

    Science.gov (United States)

    Limongelli, Vittorio; Bonomi, Massimiliano; Marinelli, Luciana; Gervasio, Francesco Luigi; Cavalli, Andrea; Novellino, Ettore; Parrinello, Michele

    2010-01-01

    The widely used nonsteroidal anti-inflammatory drugs block the cyclooxygenase enzymes (COXs) and are clinically used for the treatment of inflammation, pain, and cancers. A selective inhibition of the different isoforms, particularly COX-2, is desirable, and consequently a deeper understanding of the molecular basis of selective inhibition is of great demand. Using an advanced computational technique we have simulated the full dissociation process of a highly potent and selective inhibitor, SC-558, in both COX-1 and COX-2. We have found a previously unreported alternative binding mode in COX-2 explaining the time-dependent inhibition exhibited by this class of inhibitors and consequently their long residence time inside this isoform. Our metadynamics-based approach allows us to illuminate the highly dynamical character of the ligand/protein recognition process, thus explaining a wealth of experimental data and paving the way to an innovative strategy for designing new COX inhibitors with tuned selectivity. PMID:20215464

  2. [Urease inhibition by polymer analogs of substrate and thiophosphamides].

    Science.gov (United States)

    Metelitsa, D I; Tarun, E I; Puchkaev, A V; Losev, Iu P

    2001-01-01

    Inhibition of soybean urease by polymeric substrate analogues, urea and thiourea polydisulfides (PDSU and PDSTU, respectively), or three thiophosphoric acid amides (TPAA), tri-(N-3-hydroxyphenyl)thiophosphamide (1), tri-(N-4,4'-aminodiphenyl)thiophosphamide, and di-oxy-(N-alpha-piridyl)thiophosphamide (3) was studied in aqueous solutions at various pH values. The inhibitory effects of all these substances were reversible and competitive with the lowest inhibition constant Ki 2.8 microM for TPAA-1 at pH 3.85. Above and below this pH value, Ki increased reaching 24 [mu]M at pH 7.2. All test substances inhibited urease comparably with known inhibitors such as thiols (cysteamine, etc.) and hydroxamic acid derivatives, but were less efficient than phosphorodiamidates. Structural features of possible urease inhibitors of higher efficiency were proposed.

  3. Bim Inhibits Autophagy by Recruiting Beclin 1 to Microtubules

    Science.gov (United States)

    Luo, Shouqing; Garcia-Arencibia, Moises; Zhao, Rui; Puri, Claudia; Toh, Pearl P.C.; Sadiq, Oana; Rubinsztein, David C.

    2012-01-01

    Summary Bim is a proapoptotic BH3-only Bcl-2 family member. In response to death stimuli, Bim dissociates from the dynein light chain 1 (DYNLL1/LC8), where it is inactive, and can then initiate Bax/Bak-mediated mitochondria-dependent apoptosis. We found that Bim depletion increases autophagosome synthesis in cells and in vivo, and this effect is inhibited by overexpression of cell death-deficient Bim. Bim inhibits autophagy by interacting with Beclin 1, an autophagy regulator, and this interaction is facilitated by LC8. Bim bridges the Beclin 1-LC8 interaction and thereby inhibits autophagy by mislocalizing Beclin 1 to the dynein motor complex. Starvation, an autophagic stimulus, induces Bim phosphorylation, which abrogates LC8 binding to Bim, leading to dissociation of Bim and Beclin 1. Our data suggest that Bim switches locations between apoptosis-inactive/autophagy-inhibitory and apoptosis-active/autophagy-permissive sites. PMID:22742832

  4. Study of electroplated silver-palladium biofouling inhibiting coating

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Hilbert, Lisbeth Rischel; Møller, Per

    The undesired microbial and biofilm adhesions on the surfaces of food industrial facilities, water supply systems and etc. are so called as “biofouling”. Biofouling can cause many undesirable effects. Until now for solving biofouling, there are few non-toxic inhibiting treatments. In this study......, a new coating has been designed to form an inhibiting effect on the surface by itself. In this way, it is desired that the release of any matter will be in low concentration. This design is based on silver combined with nobler palladium, both with catalytic properties. Due to the potential difference...... between silver and palladium while contacting with an electrolyte, the surface can form numerous discrete anodic and cathodic areas, so that an inhibiting reaction can be formed. In this paper, a series of electrochemical and biological tests were conducted to study the properties of these surfaces...

  5. Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives

    Directory of Open Access Journals (Sweden)

    Shih-Chen Shi

    2016-07-01

    Full Text Available The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC, hydroxypropyl methylcellulose phthalate (HPMCP, and hydroxypropyl methylcellulose acetate succinate (HPMCAS film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate promising anti-corrosion performance of HPMC and HPMCP. With increasing film thickness, both materials reveal improvement in corrosion inhibition. Moreover, because of a hydrophobic surface and lower moisture content, HPMCP shows better anti-corrosion performance than HPMCAS. The study is of certain importance for designing green corrosion inhibitors of high speed steel surfaces by the use of biopolymer derivatives.

  6. Neutrophil chemotaxis by Propionibacterium acnes lipase and its inhibition.

    Science.gov (United States)

    Lee, W L; Shalita, A R; Suntharalingam, K; Fikrig, S M

    1982-01-01

    The chemoattraction of Propionibacterium acnes lipase for neutrophils and the effect of lipase inhibitor and two antibiotic agents on the chemotaxis were evaluated. Of the various fractions tested, partially purified lipase (fraction 2c) was the most active cytotaxin produced by P. acnes. Serum mediators were not required for the generation of chemotaxis by lipase in vitro. Diisopropyl phosphofluoridate at low concentration (10(-4) mM) completely inhibited lipase activity as well as polymorphonuclear leukocyte chemotaxis generated by lipase. Tetracycline hydrochloride and erythromycin base at concentrations of 10(-1) mM and 1 mM, respectively, caused 100% inhibition of PMN migration toward lipase or zymosan-activated serum. The inhibiting activity of the antibiotics was directed against cells independently of any effect on lipase. Chemotaxis by P. acnes lipase suggests a wider role for this enzyme in the inflammatory process and the pathogenesis of acne vulgaris.

  7. Inhibition of the mixed leukocyte reaction by alloantisera in man

    International Nuclear Information System (INIS)

    Jonker, M.; Leeuwen, A. van; Rood, J.J. van

    1977-01-01

    The incidence of MLC(mixed leukocyte culture)-inhibiting antibodies was determined in 42 pregnancy sera. MLC's were carried out between the cells from the serum donor and her husband in the presence of nonimmune AB serum and the test serum. Fifty per cent of the sera reduced the MLC response to less than 40% of the control values. Only four sera had lymphocytotoxic activity. The inhibition was strong against the specific immunizor, less strong against random unrelated cells and weak against cells which were SD(serologically defined)-identical with the serum donor. Absorptions with lymphocytes and platelets were carried out. Lymphocytes removed activity in three of the four sera tested. Platelets removed activity from one serum. It was concluded that both anti-LD(lymphocyte defined) and anti-SD antibodies were able to inhibit the MLR (mixed leukocyte reaction) at the stimulator cell level. (author)

  8. Metformin inhibits the development and metastasis of ovarian cancer.

    Science.gov (United States)

    Wu, Buchu; Li, Shu; Sheng, Lili; Zhu, Jing; Gu, Liying; Shen, Haoran; La, Duanduan; Hambly, Brett D; Bao, Shisan; Di, Wen

    2012-09-01

    The aim of this study was to investigate the role of metformin in the regulation of development and metastasis of ovarian carcinoma cell lines in vitro and ovarian cancer in a nude mouse model in vivo. The effects of metformin on the ability of two high-metastatic potential human ovarian cancer cell lines (SKOV3 and HO8910-PM) to adhere, invade and migrate in vitro were observed by means of a cell adhesion test, cell invasion test and cell migration test. The size and number of the inoculated and metastatic tumours in vivo in a nude mouse were determined following intraperitoneal injection of metformin. Furthermore, the extent of angiogenesis (vWF) and macrophage infiltration in the tumour were determined. Proliferation, migration, invasion and adhesion of ovarian cancer cells were significantly inhibited (Pmetformin inhibited hepatic, intestinal and lung metastasis (Pmetformin inhibits the development and metastasis of ovarian cancer by reducing cellular-ECM interactions, neovascularisation and macrophage infiltration.

  9. Neural signature of behavioural inhibition in women with bulimia nervosa.

    Science.gov (United States)

    Skunde, Mandy; Walther, Stephan; Simon, Joe J; Wu, Mudan; Bendszus, Martin; Herzog, Wolfgang; Friederich, Hans-Christoph

    2016-08-01

    Impaired inhibitory control is considered a behavioural phenotype in patients with bulimia nervosa. However, the underlying neural correlates of impaired general and food-specific behavioural inhibition are largely unknown. Therefore, we investigated brain activation during the performance of behavioural inhibition to general and food-related stimuli in adults with bulimia nervosa. Women with bulimia and healthy control women underwent event-related fMRI while performing a general and a food-specific no-go task. We included 28 women with bulimia nervosa and 29 healthy control women in our study. On a neuronal level, we observed significant group differences in response to general no-go stimuli in women with bulimia nervosa with high symptom severity; compared with healthy controls, the patients showed reduced activation in the right sensorimotor area (postcentral gyrus, precentral gyrus) and right dorsal striatum (caudate nucleus, putamen). The present results are limited to adult women with bulimia nervosa. Furthermore, it remains unclear whether impaired behavioural inhibition in patients with this disorder are a cause or consequence of chronic illness. Our findings suggest that diminished frontostriatal brain activation in patients with bulimia nervosa contribute to the severity of binge eating symptoms. Gaining further insight into the neural mechanisms of behavioural inhibition problems in individuals with this disorder may inform brain-directed treatment approaches and the development of response inhibition training approaches to improve inhibitory control in patients with bulimia nervosa. The present study does not support greater behavioural and neural impairments to food-specific behavioural inhibition in these patients.

  10. Ammonium inhibition of nitrogenase activity in Herbaspirillum seropedicae

    Energy Technology Data Exchange (ETDEWEB)

    Fu, H.; Burris, R.H. (Univ. of Wisconsin, Madison (USA))

    1989-06-01

    The effect of oxygen, ammonium ion, and amino acids on nitrogenase activity in the root-associated N{sub 2}-fixing bacterium Herbaspirillum seropedicae was investigated in comparison with Azospirillum spp. and Rhodospirillum rubrum. H. seropedicae is microaerophilic, and its optimal dissolved oxygen level is from 0.04 to 0.2 kPa for dinitrogen fixation but higher when it is supplied with fixed nitrogen. No nitrogenase activity was detected when the dissolved O{sub 2} level corresponded to 4.0 kPa. Ammonium, a product of the nitrogenase reaction, reversible inhibited nitrogenase activity when added to derepressed cell cultures. However, the inhibition of nitrogenase activity was only partial even with concentrations of ammonium chloride as high as 20 mM. Amides such as glutamine and asparagine partially inhibited nitrogenase activity, but glutamate did not. Nitrogenase in crude extracts prepared from ammonium-inhibited cells showed activity as high as in extracts from N{sub 2}-fixing cells. The pattern of the dinitrogenase and the dinitrogenase reductase revealed by the immunoblotting technique did not change upon ammonium chloride treatment of cells in vivo. No homologous sequences were detected with the draT-draG probe from Azospirillum lipoferum. There is no clear evidence that ADP-ribosylation of the dinitrogenase reductase is involved in the ammonium inhibition of H. seropedicae. The uncoupler carbonyl cyanide m-chlorophenylhydrazone decreased the intracellular ATP concentration and inhibited the nitrogenase activity of whole cells. The ATP pool was significantly disturbed when cultures were treated with ammonium in vivo.

  11. Nesfatin-1 inhibits ovarian epithelial carcinoma cell proliferation in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yang; Pang, Xiaoyan; Dong, Mei; Wen, Fang, E-mail: wenfang64@hotmail.com; Zhang, Yi, E-mail: syzi960@yahoo.com

    2013-11-01

    Highlights: •Nesfatin-1 inhibits the proliferation and growth of HO-8910 cells by G1 phase arrest. •Nesfatin-1 enhances HO-8910 cell apoptosis. •Nesfatin-1 inhibits HO-8910 cell proliferation via mTOR and RhoA/ROCK signaling pathway. •The first report of nesfatin-1-mediated proliferation in ovarian epithelial carcinoma. -- Abstract: Nesfatin-1, an 82-amino-acid peptide derived from a 396-amino-acid precursor protein nucleobindin 2 (NUCB2), was originally identified in hypothalamic nuclei involved in the regulation of food intake. It was recently reported that nesfatin-1 is a novel depot specific adipokine preferentially produced by subcutaneous tissue, with obesity- and food deprivation-regulated expression. Although a relation between ovarian cancer mortality and obesity has been previously established, a role of nesfatin-1 in ovarian epithelial carcinoma remains unknown. The aim of the present study is to examine the effect of nesfatin-1 on ovary carcinoma cells proliferation. We found that nesfatin-1 inhibits the proliferation and growth of HO-8910 cells by G1 phase arrest, this inhibition could be abolished by nesfatin-1 neutralizing antibody. Nesfatin-1 enhances HO-8910 cell apoptosis, activation of mammalian target of rapamycin (mTOR) and RhoA/ROCK signaling pathway block the effects of nesfatin-1-induced apoptosis, therefore reverses the inhibition of HO-8910 cell proliferation by nesfatin-1. In conclusion, the present study demonstrated that nesfatin-1 can inhibit the proliferation in human ovarian epithelial carcinoma cell line HO-8910 cells through inducing apoptosis via mTOR and RhoA/ROCK signaling pathway. This study provides a novel regulatory signaling pathway of nesfatin-1-regulated ovarian epithelial carcinoma growth and may contribute to ovarian cancer prevention and therapy, especially in obese patients.

  12. Fcγ receptor-mediated inflammation inhibits axon regeneration.

    Directory of Open Access Journals (Sweden)

    Gang Zhang

    Full Text Available Anti-glycan/ganglioside antibodies are the most common immune effectors found in patients with Guillain-Barré Syndrome, which is a peripheral autoimmune neuropathy. We previously reported that disease-relevant anti-glycan autoantibodies inhibited axon regeneration, which echo the clinical association of these antibodies and poor recovery in Guillain-Barré Syndrome. However, the specific molecular and cellular elements involved in this antibody-mediated inhibition of axon regeneration are not previously defined. This study examined the role of Fcγ receptors and macrophages in the antibody-mediated inhibition of axon regeneration. A well characterized antibody passive transfer sciatic nerve crush and transplant models were used to study the anti-ganglioside antibody-mediated inhibition of axon regeneration in wild type and various mutant and transgenic mice with altered expression of specific Fcγ receptors and macrophage/microglia populations. Outcome measures included behavior, electrophysiology, morphometry, immunocytochemistry, quantitative real-time PCR, and western blotting. We demonstrate that the presence of autoantibodies, directed against neuronal/axonal cell surface gangliosides, in the injured mammalian peripheral nerves switch the proregenerative inflammatory environment to growth inhibitory milieu by engaging specific activating Fcγ receptors on recruited monocyte-derived macrophages to cause severe inhibition of axon regeneration. Our data demonstrate that the antibody orchestrated Fcγ receptor-mediated switch in inflammation is one mechanism underlying inhibition of axon regeneration. These findings have clinical implications for nerve repair and recovery in antibody-mediated immune neuropathies. Our results add to the complexity of axon regeneration in injured peripheral and central nervous systems as adverse effects of B cells and autoantibodies on neural injury and repair are increasingly recognized.

  13. [Cabergoline in the inhibition of lactogenesis and suppression of lactopoiesis].

    Science.gov (United States)

    Bracco, P L; Armentano, G; Pellegrini, A; Sugliano, G C; Tornatore, G P

    1997-10-01

    1) Evaluate the capacity of cabergoline to inhibit lactogenesis by the administration of a single dose of 1 mg within 24 h of birth, primary inhibition. 2) Evaluate the capacity of cabergoline to suppress lactopoiesis (lactation) by the administration of 0.25 mg twice a day for 2 days, secondary inhibition. 3) Evaluate the collateral effects of cabergoline at these two doses. 4) Evaluate the reduction rate of prolactin (PRL) at 4 and 14 days after cabergoline administration. A prospective study was performed from 1/2/1995 to 31/1/1996 in 100 puerperae with indications for lactation with follow-up at 4 and 14 days after drug administration. The study was performed in the Division of Gynecology and Obstetrics of Sanremo Hospital in collaboration with the Analysis Service. Cabergoline inhibited primary and secondary lactation in all the puerperae examined. In 92% of cases lactation was suppressed following a single dose whereas a second treatment cycle was required in 8%. Twenty-two cases reported slight collateral effects without the need to resort to additional treatment. In 4 cases the collateral effects were of moderate intensity and it was necessary to administer symptomatic treatment. Mean levels of serum PRL at 4 and 14 days after cabergoline administration were respectively 12.5 and 18.2 ng/ml. Cabergoline, a new dopaminergic drug with long-term inhibition of PRL production and secretion, can inhibit lactogenesis and lactopoies in 92% of cases at a dose of 1 mg; it can reduce long-term PRL levels (18.2 ng/ml) and in 4% it is necessary to resort to symptomatic treatment of the undesirable effects caused.

  14. Nesfatin-1 inhibits ovarian epithelial carcinoma cell proliferation in vitro

    International Nuclear Information System (INIS)

    Xu, Yang; Pang, Xiaoyan; Dong, Mei; Wen, Fang; Zhang, Yi

    2013-01-01

    Highlights: •Nesfatin-1 inhibits the proliferation and growth of HO-8910 cells by G1 phase arrest. •Nesfatin-1 enhances HO-8910 cell apoptosis. •Nesfatin-1 inhibits HO-8910 cell proliferation via mTOR and RhoA/ROCK signaling pathway. •The first report of nesfatin-1-mediated proliferation in ovarian epithelial carcinoma. -- Abstract: Nesfatin-1, an 82-amino-acid peptide derived from a 396-amino-acid precursor protein nucleobindin 2 (NUCB2), was originally identified in hypothalamic nuclei involved in the regulation of food intake. It was recently reported that nesfatin-1 is a novel depot specific adipokine preferentially produced by subcutaneous tissue, with obesity- and food deprivation-regulated expression. Although a relation between ovarian cancer mortality and obesity has been previously established, a role of nesfatin-1 in ovarian epithelial carcinoma remains unknown. The aim of the present study is to examine the effect of nesfatin-1 on ovary carcinoma cells proliferation. We found that nesfatin-1 inhibits the proliferation and growth of HO-8910 cells by G1 phase arrest, this inhibition could be abolished by nesfatin-1 neutralizing antibody. Nesfatin-1 enhances HO-8910 cell apoptosis, activation of mammalian target of rapamycin (mTOR) and RhoA/ROCK signaling pathway block the effects of nesfatin-1-induced apoptosis, therefore reverses the inhibition of HO-8910 cell proliferation by nesfatin-1. In conclusion, the present study demonstrated that nesfatin-1 can inhibit the proliferation in human ovarian epithelial carcinoma cell line HO-8910 cells through inducing apoptosis via mTOR and RhoA/ROCK signaling pathway. This study provides a novel regulatory signaling pathway of nesfatin-1-regulated ovarian epithelial carcinoma growth and may contribute to ovarian cancer prevention and therapy, especially in obese patients

  15. Response inhibition signals and miscoding of direction in dorsomedial striatum

    Directory of Open Access Journals (Sweden)

    Daniel W Bryden

    2012-09-01

    Full Text Available The ability to inhibit action is critical for everyday behavior and is affected by a variety of disorders. Behavioral control and response inhibition is thought to depend on a neural circuit that includes the dorsal striatum, yet the neural signals that lead to response inhibition and its failure are unclear. To address this issue, we recorded from neurons in rat dorsomedial striatum (mDS in a novel task in which rats responded to a spatial cue that signaled that reward would be delivered either to the left or to the right. On 80% of trials rats were instructed to respond in the direction cued by the light (GO. On 20% of trials a second light illuminated instructing the rat to refrain from making the cued movement and move in the opposite direction (STOP. Many neurons in mDS encoded direction, firing more or less strongly for GO movements made ipsilateral or contralateral to the recording electrode. Neurons that fired more strongly for contralateral GO responses were more active when rats were faster, showed reduced activity on STOP trials, and miscoded direction on errors, suggesting that when these neurons were overly active, response inhibition failed. Neurons that decreased firing for contralateral movement were excited during trials in which the rat was required to stop the ipsilateral movement. For these neurons activity was reduced when errors were made and was negatively correlated with movement time suggesting that when these neurons were less active on STOP trials, response inhibition failed. Finally, the activity of a significant number of neurons represented a global inhibitory signal, firing more strongly during response inhibition regardless of response direction. Breakdown by cell type suggests that putative medium spiny neurons tended to fire more strongly under STOP trials, whereas putative interneurons exhibited both activity patterns. 

  16. Reward prospect rapidly speeds up response inhibition via reactive control.

    Science.gov (United States)

    Boehler, Carsten N; Schevernels, Hanne; Hopf, Jens-Max; Stoppel, Christian M; Krebs, Ruth M

    2014-06-01

    Response inhibition is an important cognitive-control function that allows for already-initiated or habitual behavioral responses to be promptly withheld when needed. A typical paradigm to study this function is the stop-signal task. From this task, the stop-signal response time (SSRT) can be derived, which indexes how rapidly an already-initiated response can be canceled. Typically, SSRTs range around 200 ms, identifying response inhibition as a particularly rapid cognitive-control process. Even so, it has recently been shown that SSRTs can be further accelerated if successful response inhibition is rewarded. Since this earlier study effectively ruled out differential preparatory (proactive) control adjustments, the reward benefits likely relied on boosted reactive control. Yet, given how rapidly such control processes would need to be enhanced, alternative explanations circumventing reactive control are important to consider. We addressed this question with an fMRI study by gauging the overlap of the brain networks associated with reward-related and response-inhibition-related processes in a reward-modulated stop-signal task. In line with the view that reactive control can indeed be boosted swiftly by reward availability, we found that the activity in key brain areas related to response inhibition was enhanced for reward-related stop trials. Furthermore, we observed that this beneficial reward effect was triggered by enhanced connectivity between task-unspecific (reward-related) and task-specific (inhibition-related) areas in the medial prefrontal cortex (mPFC). The present data hence suggest that reward information can be translated very rapidly into behavioral benefits (here, within ~200 ms) through enhanced reactive control, underscoring the immediate responsiveness of such control processes to reward availability in general.

  17. An IP-10 (CXCL10)-Derived Peptide Inhibits Angiogenesis

    Science.gov (United States)

    Yates-Binder, Cecelia C.; Rodgers, Margaret; Jaynes, Jesse; Wells, Alan; Bodnar, Richard J.; Turner, Timothy

    2012-01-01

    Angiogenesis plays a critical role in processes such as organ development, wound healing, and tumor growth. It requires well-orchestrated integration of soluble and matrix factors and timely recognition of such signals to regulate this process. Previous work has shown that newly forming vessels express the chemokine receptor CXC receptor 3 (CXCR3) and, activation by its ligand IP-10 (CXCL10), both inhibits development of new vasculature and causes regression of newly formed vessels. To identify and develop new therapeutic agents to limit or reverse pathological angiogenesis, we identified a 21 amino acid fragment of IP-10, spanning the α-helical domain residues 77–98, that mimic the actions of the whole IP-10 molecule on endothelial cells. Treatment of the endothelial cells with the 22 amino acid fragment referred to as IP-10p significantly inhibited VEGF-induced endothelial motility and tube formation in vitro, properties critical for angiogenesis. Using a Matrigel plug assay in vivo, we demonstrate that IP-10p both prevented vessel formation and induced involution of nascent vessels. CXCR3 neutralizing antibody was able to block the inhibitory effects of the IP-10p, demonstrating specificity of the peptide. Inhibition of endothelial function by IP-10p was similar to that described for IP-10, secondary to CXCR3-mediated increase in cAMP production, activation of PKA inhibiting cell migration, and inhibition of VEGF-mediated m-calpain activation. IP-10p provides a novel therapeutic agent that inhibits endothelial cell function thus, allowing for the modulation of angiogenesis. PMID:22815829

  18. Innate inhibition of adaptive immunity: Mycobacterium tuberculosis-induced IL-6 inhibits macrophage responses to IFN-gamma.

    Science.gov (United States)

    Nagabhushanam, Vijaya; Solache, Alejandra; Ting, Li-Min; Escaron, Claire J; Zhang, Jennifer Y; Ernst, Joel D

    2003-11-01

    In humans and in mice, control of the intracellular pathogen, Mycobacterium tuberculosis (Mtb), requires IFN-gamma. Although the adaptive immune response results in production of substantial amounts of IFN-gamma in response to Mtb, the immune response is unable to eradicate the infection in most cases. We have previously reported evidence that Mtb inhibits macrophage responses to IFN-gamma, suggesting that this may limit the ability of IFN-gamma to stimulate macrophages to kill Mtb. We have also observed that uninfected macrophages, adjacent to infected macrophages in culture, exhibit decreased responses to IFN-gamma. Here we report that IL-6 secreted by Mtb-infected macrophages inhibits the responses of uninfected macrophages to IFN-gamma. IL-6 selectively inhibits a subset of IFN-gamma-responsive genes at the level of transcriptional activation without inhibiting activation or function of STAT1. Inhibition of macrophage responses to IFN-gamma by IL-6 requires new protein synthesis, but this effect is not attributable to suppressor of cytokine signaling 1 or 3. These results reveal a novel function for IL-6 and indicate that IL-6 secreted by Mtb-infected macrophages may contribute to the inability of the cellular immune response to eradicate infection.

  19. Inhibition of miR-29c promotes proliferation, and inhibits apoptosis and differentiation in P19 embryonic carcinoma cells.

    Science.gov (United States)

    Chen, Bin; Song, Guixian; Liu, Ming; Qian, Lingmei; Wang, Lihua; Gu, Haitao; Shen, Yahui

    2016-03-01

    In our previous study, the upregulation of microRNA (miR)-29c was identified in the mother of a fetus with a congenital heart defect. However, the functional and regulatory mechanisms of miR‑29c in the development of the heart remain to be elucidated. In the present study, the role and mechanism of miR‑29c inhibition in heart development were investigated in an embryonic carcinoma cell model. Inhibition of miR‑29c promoted proliferation, and suppressed the apoptosis and differentiation of P19 cells. It was also demonstrated that Wingless‑related MMTV integration site 4 (Wnt4) was a target of miR‑29c, determined using bioinformatic analysis combined with luciferase assays. The inhibition of miR‑29c stimulated the WNT4/β‑catenin pathway, promoting proliferation of the P19 cells, but suppressing their differentiation into cardiomyocytes. Furthermore, the inhibition of miR‑29c promoted the expression of B cell lymphoma‑2 and inhibited cell apoptosis. These results demonstrate the significance of miR‑29c in the process of cardiac development and suggest that miR-29c dysregulation may be associated with the occurrence of CHD. Thus, miR-29c may have therapeutic potential in the future.

  20. Statins improve NASH via inhibition of RhoA and Ras

    DEFF Research Database (Denmark)

    Schierwagen, Robert; Maybüchen, Lara; Hittatiya, Kanishka

    2016-01-01

    in NASH. SMV blunted fibrosis due to inhibition of both RhoA/Rho kinase and Ras/ERK pathways. Interestingly, inhibition of RAC1 and Ras (by LT) failed to decrease fibrosis to the same extent. Inhibition of RAC1 (by NSC) showed no significant effect at all. Inhibition of RhoA and Ras downstream signaling...

  1. beta-Chloro-L-alanine inhibition of the Escherichia coli alanine-valine transaminase.

    OpenAIRE

    Whalen, W A; Wang, M D; Berg, C M

    1985-01-01

    beta-Chloro-L-alanine, an amino acid analog which inhibits a number of enzymes, reversibly inhibited the Escherichia coli K-12 alanine-valine transaminase, transaminase C. This inhibition, along with the inhibition of transaminase B, accounted for the isoleucine-plus-valine requirement of E. coli in the presence of beta-chloro-L-alanine.

  2. Inhibition of human aromatase complex (CYP19) by antiepileptic drugs

    DEFF Research Database (Denmark)

    Jacobsen, Naja Wessel; Halling-Sørensen, Bent; Birkved, Franziska Maria A Kramer

    2008-01-01

    Antiepileptic drugs and epilepsy are often associated with sexual disorder in women such as hyperandrogenism, menstrual disorders and ovarian cysts. In children, until puberty, a hormone imbalance may influence many aspects of development, e.g. growth and sexual maturation. The aromatase complex...... is the enzyme system that converts androgens to estrogens and consequently an inhibition may induce a hormone imbalance. Twelve antiepileptic drugs, used in mono or polytherapy for the treatment of children, were tested for their ability to inhibit aromatase (CYP19) with commercially available microsomes from...

  3. Siderocalin inhibits the intracellular replication of Mycobacterium tuberculosis in macrophages

    DEFF Research Database (Denmark)

    Johnson, Erin E; Srikanth, Chittur V; Sandgren, Andreas

    2010-01-01

    Siderocalin is a secreted protein that binds to siderophores to prevent bacterial iron acquisition. While it has been shown to inhibit the growth of Mycobacterium tuberculosis (M.tb) in extracellular cultures, its effect on this pathogen within macrophages is not clear. Here, we show that sideroc......Siderocalin is a secreted protein that binds to siderophores to prevent bacterial iron acquisition. While it has been shown to inhibit the growth of Mycobacterium tuberculosis (M.tb) in extracellular cultures, its effect on this pathogen within macrophages is not clear. Here, we show...

  4. Noninvasive optical inhibition with a red-shifted microbial rhodopsin

    DEFF Research Database (Denmark)

    Chuong, Amy S; Miri, Mitra L; Busskamp, Volker

    2014-01-01

    Optogenetic inhibition of the electrical activity of neurons enables the causal assessment of their contributions to brain functions. Red light penetrates deeper into tissue than other visible wavelengths. We present a red-shifted cruxhalorhodopsin, Jaws, derived from Haloarcula (Halobacterium......) salinarum (strain Shark) and engineered to result in red light-induced photocurrents three times those of earlier silencers. Jaws exhibits robust inhibition of sensory-evoked neural activity in the cortex and results in strong light responses when used in retinas of retinitis pigmentosa model mice. We also...

  5. Potent Protein Glycation Inhibition of Plantagoside in Plantago major Seeds

    Directory of Open Access Journals (Sweden)

    Nobuyasu Matsuura

    2014-01-01

    Full Text Available Plantagoside (5,7,4′,5′-tetrahydroxyflavanone-3′-O-glucoside and its aglycone (5,7,3′,4′,5′-pentahydroxyflavanone, isolated from a 50% ethanol extract of Plantago major seeds (Plantaginaceae, were established to be potent inhibitors of the Maillard reaction. These compounds also inhibited the formation of advanced glycation end products in proteins in physiological conditions and inhibited protein cross-linking glycation. These results indicate that P. major seeds have potential therapeutic applications in the prevention of diabetic complications.

  6. Angiotensin-converting enzyme inhibition in diabetic nephropathy

    DEFF Research Database (Denmark)

    Parving, H H; Rossing, P; Hommel, E

    1995-01-01

    The aim of our prospective study was to evaluate putative progression promoters, kidney function, and prognosis during long-term treatment with angiotensin-converting enzyme inhibition in insulin-dependent diabetes mellitus patients suffering from diabetic nephropathy. Eighteen consecutive......, albuminuria (geometric mean +/- antilog SE) 982 +/- 1.2 micrograms/min, and GFR 98 +/- 5 mL/min/1.73 m2. Angiotensin-converting enzyme inhibition induced a significant reduction during the whole treatment period of blood pressure (137/85 +/- 3/1 mm Hg; P

  7. Inhibition delay increases neural network capacity through Stirling transform

    Science.gov (United States)

    Nogaret, Alain; King, Alastair

    2018-03-01

    Inhibitory neural networks are found to encode high volumes of information through delayed inhibition. We show that inhibition delay increases storage capacity through a Stirling transform of the minimum capacity which stabilizes locally coherent oscillations. We obtain both the exact and asymptotic formulas for the total number of dynamic attractors. Our results predict a (ln2) -N-fold increase in capacity for an N -neuron network and demonstrate high-density associative memories which host a maximum number of oscillations in analog neural devices.

  8. Inhibition of tyrosinase activity and melanine pigmentation by 2-hydroxytyrosol

    Directory of Open Access Journals (Sweden)

    Ryuji Uchida

    2014-04-01

    Full Text Available 2-Hydroxytyrosol (2-HT, originally reported as a synthetic compound, was isolated for the first time as a fungal metabolite. 2-HT was found to inhibit mushroom tyrosinase with an IC50 value of 13.0 µmol/L. Furthermore, 2-HT dose-dependently inhibited tyrosinase activity (IC50, 32.5 µmol/L in the cell-free extract of B16 melanoma cells and α-melanocyte stimulating hormone (α-MSH-stimulated melanin formation in intact B16 melanoma cells.

  9. Efficacy of Lysine-Specific Demethylase 1 Inhibition in PCa

    Science.gov (United States)

    2016-08-01

    new insight into the actions of both LSD1 and FOXA1 that may be relevant in a number of cancers. We further found that short-term treatment with LSD1...how PCa cells adapt to LSD1 inhibition or loss, and to determine whether effective therapies targeting LSD1 can be developed for PCa. 15. SUBJECT...chromatin (Fig. 2B). Finally, we similarly examined the effects of overexpression the wild -type LSD1 (Fig. 3A,B). Conversely to the LSD1 inhibition

  10. Inhibition of brain tumor cell proliferation by alternating electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hyesun; Oh, Seung-ick; Hong, Sunghoi, E-mail: shong21@korea.ac.kr, E-mail: radioyoon@korea.ac.kr [School of Biosystem and Biomedical Science, Korea University, Seoul 136-703 (Korea, Republic of); Sung, Jiwon; Jeong, Seonghoon; Yoon, Myonggeun, E-mail: shong21@korea.ac.kr, E-mail: radioyoon@korea.ac.kr [Department of Bio-convergence Engineering, Korea University, Seoul 136-703 (Korea, Republic of); Koh, Eui Kwan [Seoul Center, Korea Basic Science Institute, Seoul 136-713 (Korea, Republic of)

    2014-11-17

    This study was designed to investigate the mechanism by which electric fields affect cell function, and to determine the optimal conditions for electric field inhibition of cancer cell proliferation. Low-intensity (<2 V/cm) and intermediate-frequency (100–300 kHz) alternating electric fields were applied to glioblastoma cell lines. These electric fields inhibited cell proliferation by inducing cell cycle arrest and abnormal mitosis due to the malformation of microtubules. These effects were significantly dependent on the intensity and frequency of applied electric fields.

  11. Inhibition of brain tumor cell proliferation by alternating electric fields

    International Nuclear Information System (INIS)

    Jeong, Hyesun; Oh, Seung-ick; Hong, Sunghoi; Sung, Jiwon; Jeong, Seonghoon; Yoon, Myonggeun; Koh, Eui Kwan

    2014-01-01

    This study was designed to investigate the mechanism by which electric fields affect cell function, and to determine the optimal conditions for electric field inhibition of cancer cell proliferation. Low-intensity (<2 V/cm) and intermediate-frequency (100–300 kHz) alternating electric fields were applied to glioblastoma cell lines. These electric fields inhibited cell proliferation by inducing cell cycle arrest and abnormal mitosis due to the malformation of microtubules. These effects were significantly dependent on the intensity and frequency of applied electric fields

  12. Therapeutic complement inhibition – from experimental to clinical medicine.

    Science.gov (United States)

    Lappegård, Knut Tore; Bjerre, Anna; Tjønnfjord, Geir Erland; Mollnes, Tom Eirik

    2015-10-20

    Internationally, the use of the C5-inhibiting monoclonal antibody eculizumab has in the course of just a few years become the first choice of treatment of atypical haemolytic uraemic syndrome and the most severe phenotypes of paroxysmal nocturnal haemoglobinuria. At present eculizumab is the only complement inhibitor in ordinary clinical use. This despite the fact that there only exists one randomised, placebo-controlled trial of eculizumab for paroxysmal nocturnal haemoglobinuria and none for atypical haemolytic uraemic syndrome, and that the therapy is very costly. There is reason to believe that complement inhibition as therapy will increase in the future, and that other drugs will also prove to be effective.

  13. Corrosion inhibition of aqueous solutions of inorganic mineral acids

    Energy Technology Data Exchange (ETDEWEB)

    Stanford, J.R.

    1971-06-15

    A particularly corrosive use of mineral acids is the employment of 15% solutions and, in some instances, even more concentrated solutions of hydrochloric acid in oil well acidizing applications. It has been found that aqueous solutions of inorganic mineral acids, particularly hydrochloric acid solutions, may be inhibited against their corrosive tendencies toward ferrous metals by adding novel compositions of the invention whereby inhibited mineral acid aqueous solutions are provided. In its simplest embodiment the invention comprises using in combination the Mannich reaction products of a hydroabietyl amine, formaldehyde, and certain aliphatic aldehydes in combination with an acetylenic alcohol which contains from 3 to 12 carbon atoms. (7 claims)

  14. DAX-1 Inhibits Hepatocellular Carcinoma Proliferation by Inhibiting β-Catenin Transcriptional Activity

    Directory of Open Access Journals (Sweden)

    Hong-Lei Jiang

    2014-08-01

    Full Text Available Background/Aims: Hepatocellular carcinoma (HCC represents the most common type of liver cancer. DAX1 (dosage-sensitive sex reversal adrenal hypoplasia congenital critical region on X chromosome, gene 1, an atypical member of the nuclear receptor family due to lack of classical DNA-binding domains, has been known for its fundamental roles in the development, especially in the sex determination and steroidogenesis. Previous studies also showed that DAX-1 played a critical role in endocrine and sex steroid-dependent neoplasms such as adrenocortical, pituitary, endometrial, and ovarian tumors. However, its biological roles in the development of HCC remain largely unexplored. Methods: Real-time PCR and Western blot were used to detect the expression of DAX-1 in HCC tissues and cell lines. Immunoprecipitation (IP assay was used to show the interaction between DAX-1 and β-Catenin. Small interfering RNA (siRNA was used to silence the expression of DAX-1. BrdU incorporation and Cell-cycle assays were used to detect the role of DAX-1 in HCC cells proliferation. Migration and invasion assays were carried out to test the metastasis ability of DAX-1 in HCC cells. Results: In the present study, we found that mRNA and protein levels of DAX-1 were down-regulated in HCC tissues and cell lines. Furthermore, overexpression of DAX-1 could inhibit while its knockdown using small interfering RNA promoted cell proliferation in several HCC cell lines. At the molecular level, we demonstrated that DAX-1 could interact with β-Catenin and attenuate its transcriptional activity. Conclusion: Therefore, our results suggest a previously unknown DAX-1/β-Catenin molecular network controlling HCC development.

  15. Celastrol inhibits TGF-β1-induced epithelial–mesenchymal transition by inhibiting Snail and regulating E-cadherin expression

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyereen; Lee, Minjae [Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Jang, Sung-Wuk, E-mail: swjang@amc.seoul.kr [Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of)

    2013-08-09

    Highlights: •We investigated the effects of celastrol on TGF-β1-induced EMT in epithelial cells. •Celastrol regulates TGF-β1-induced morphological changes and E-cadherin expression. •Celastrol inhibits TGF-β1-induced Snail expression. •Celastrol strongly suppresses TGF-β1-induced invasion in MDCK and A549 cells. -- Abstract: The epithelial–mesenchymal transition (EMT) is a pivotal event in the invasive and metastatic potentials of cancer progression. Celastrol inhibits the proliferation of a variety of tumor cells including leukemia, glioma, prostate, and breast cancer; however, the possible role of celastrol in the EMT is unclear. We investigated the effect of celastrol on the EMT. Transforming growth factor-beta 1 (TGF-β1) induced EMT-like morphologic changes and upregulation of Snail expression. The downregulation of E-cadherin expression and upregulation of Snail in Madin–Darby Canine Kidney (MDCK) and A549 cell lines show that TGF-β1-mediated the EMT in epithelial cells; however, celastrol markedly inhibited TGF-β1-induced morphologic changes, Snail upregulation, and E-cadherin expression. Migration and invasion assays revealed that celastrol completely inhibited TGF-β1-mediated cellular migration in both cell lines. These findings indicate that celastrol downregulates Snail expression, thereby inhibiting TGF-β1-induced EMT in MDCK and A549 cells. Thus, our findings provide new evidence that celastrol suppresses lung cancer invasion and migration by inhibiting TGF-β1-induced EMT.

  16. Combination of rapamycin, CI-1040, and 17-AAG inhibits metastatic capacity of prostate cancer via Slug inhibition.

    Directory of Open Access Journals (Sweden)

    Guanxiong Ding

    Full Text Available Though prostate cancer (PCa has slow progression, the hormone refractory (HRCP and metastatic entities are substantially lethal and lack effective treatments. Transcription factor Slug is critical in regulating metastases of various tumors including PCa. Here we studied targeted therapy against Slug using combination of 3 drugs targeting 3 pathways respectively converging via Slug and further regulating PCa metastasis. Using in vitro assays we confirmed that Slug up-regulation incurred inhibition of E-cadherin that was anti-metastatic, and inhibited Bim-regulated cell apoptosis in PCa. Upstream PTEN/Akt, mTOR, Erk, and AR/Hsp90 pathways were responsible for Slug up-regulation and each of these could be targeted by rapamycin, CI-1040, and 17-AAG respectively. In 4 PCa cell lines with different traits in terms of PTEN loss and androgen sensitivity we tested the efficacy of mono- and combined therapy with the drugs. We found that metastatic capacity of the cells was maximally inhibited only when all 3 drugs were combined, due to the crosstalk between the pathways. 17-AAG decreases Slug expression via blockade of HSP90-dependent AR stability. Combination of rapamycin and CI-1040 diminishes invasiveness more potently in PCa cells that are androgen insensitive and with PTEN loss. Slug inhibited Bim-mediated apoptosis that could be rescued by mTOR/Erk/HSP90 inhibitors. Using mouse models for circulating PCa DNA quantification, we found that combination of mTOR/Erk/HSP90 inhibitors reduced circulating PCa cells in vivo significantly more potently than combination of 2 or monotherapy. Conclusively, combination of mTOR/Erk/Hsp90 inhibits metastatic capacity of prostate cancer via Slug inhibition.

  17. Inhibition of miR-29c promotes proliferation, and inhibits apoptosis and differentiation in P19 embryonic carcinoma cells

    OpenAIRE

    CHEN, BIN; SONG, GUIXIAN; LIU, MING; QIAN, LINGMEI; WANG, LIHUA; GU, HAITAO; SHEN, YAHUI

    2016-01-01

    In our previous study, the upregulation of microRNA (miR)-29c was identified in the mother of a fetus with a congenital heart defect. However, the functional and regulatory mechanisms of miR-29c in the development of the heart remain to be elucidated. In the present study, the role and mechanism of miR-29c inhibition in heart development were investigated in an embryonic carcinoma cell model. Inhibition of miR-29c promoted proliferation, and suppressed the apoptosis and differentiation of P19...

  18. Metabolites from Actinomyces Strain H6552 Extract Inhibit ...

    African Journals Online (AJOL)

    Purpose: To evaluate the effects of H6552 extract in inhibiting transforming growth factor (TGF)- mediated pulmonary fibrosis in vitro and in vivo. Methods: Maximum-nontoxic dose (MNTD) of Actinomyces H6552 extract was determined using 3-. (4,5-dimethylthiazol-2-yl)-2,5-diphhenyltetrazolium bromide (MTT) assay.

  19. Effects of Methylphenidate and Atomoxetine on Cortical Inhibition in ADHD

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2006-09-01

    Full Text Available The effects of methylphenidate (MPH, a psychostimulant, and atomoxetine (ATX, a selective norepinephrine reuptake inhibitor, on short interval-cortical inhibition (SICI were measured in motor cortex with transcranial magnetic stimulation, in a study at Cincinnati Children’s Medical Center, OH, and other centers.

  20. Inhibition effects of acetyl coumarines and thiazole derivatives on ...

    Indian Academy of Sciences (India)

    White rust formation on zinc and galvanized products due to corrosion remains a serious commercial problem in spite of many available control methods. Also zinc gets cor- roded when exposed to different industrial environment and aqueous media. To inhibit the corrosion reaction of zinc in aqueous media, the inhibitors ...

  1. Inhibition effect of flavonoid extract of Euphorbia guyoniana on the ...

    African Journals Online (AJOL)

    The influence of flavonoids extracts of three parts of Euphorbia Guyoniana towards the corrosion of type API 5L X52 steel in 15% H2SO4 has been evaluated by weight loss method and polarization technique. The results showed that extracts are a good inhibitors for API 5L X52 steel in this medium. The corrosion inhibition ...

  2. Inhibition Effect of Parthenium Hystophrous L Extracts on the ...

    African Journals Online (AJOL)

    The inhibition effect of Parthenium hystophrous L extract on the corrosion of mild steel in 1N sulphuric acid has been studied at different concentrations as well as different temperatures of inhibitor by mass loss studies, adsorption isotherms, Tafel polarization and electrochemical impedance spectroscopy (EIS) between 308 ...

  3. In vitro inhibition of pathogenic Verticillium dahliae , causal agent of ...

    African Journals Online (AJOL)

    Most of the single spore isolates and TGZ-SC-4 were found to have higher MyI efficiency than that of the rest. The results indicate that the Trichoderma isolates in this study have initial modes of action of biological control to protect potato crop against V. dahlia. Keywords: Trichoderma, potato wilt disease, growth inhibition, ...

  4. Dipsacus asperoides (Xue Duan) inhibits spinal cord injury-induced ...

    African Journals Online (AJOL)

    Dipsacus asperoides (Xue Duan) inhibits spinal cord injury-induced inflammatory responses in rats. Liang Chen, Wei-Chun Guo. Abstract. Purpose: To investigate the effect of Dipsacus asperoides (Xue Duan), a traditional Chinese medicine, on rats with spinal cord injury (SCI). Methods: In this study a total of 40 adult rats ...

  5. In vitro inhibition of the paraoxonase from human serum with ...

    African Journals Online (AJOL)

    SERVER

    2008-03-04

    Mar 4, 2008 ... precipitation and sepharose-4B-L-tyrosine-1-napthylamine hydrophobic interaction chromatography. Sulfonamide was an ... of interaction of sulfonamide with the purified enzyme indicated a different inhibition pattern for two substrates. ..... Boyd AE (1988). Sulfonylurea receptors, ion channels and fruit flies.

  6. Maturation of cognitive control: delineating response inhibition and interference suppression.

    Directory of Open Access Journals (Sweden)

    Christopher R Brydges

    Full Text Available Cognitive control is integral to the ability to attend to a relevant task whilst suppressing distracting information or inhibiting prepotent responses. The current study examined the development of these two subprocesses by examining electrophysiological indices elicited during each process. Thirteen 18 year-old adults and thirteen children aged 8-11 years (mean=9.77 years completed a hybrid Go/Nogo flanker task while continuous EEG data were recorded. The N2 topography for both response inhibition and interference suppression changed with increasing age. The neural activation associated with response inhibition became increasingly frontally distributed with age, and showed decreases of both amplitude and peak latency from childhood to adulthood, possibly due to reduced cognitive demands and myelination respectively occurring during this period. Interestingly, a significant N2 effect was apparent in adults, but not observed in children during trials requiring interference suppression. This could be due to more diffuse activation in children, which would require smaller levels of activation over a larger region of the brain than is reported in adults. Overall, these results provide evidence of distinct maturational processes occurring throughout late childhood and adolescence, highlighting the separability of response inhibition and interference suppression.

  7. Triacontanol inhibits both enzymatic and nonenzymatic lipid peroxidation.

    Science.gov (United States)

    Ramanarayan, K; Bhat, A; Shripathi, V; Swamy, G S; Rao, K S

    2000-09-01

    The effect of the plant growth regulator, triacontanol (TRIA) on lipid peroxidation was studied in three different systems: (i) isolated chloroplasts of spinach (Spinacea oleracea L.) leaves; (ii) egg lecithin liposomes; and (iii) soybean lipoxygenase (LOX) system. The nonenzymatic lipid peroxidation in isolated chloroplasts and egg lecithin liposomes was measured as the amount of thiobarbituric acid reactive substances (TBARS) formed. Inhibition of Fe2+ and/or light-induced lipid peroxidation by TRIA was observed in both isolated chloroplasts and egg lecithin liposomes. The kinetics of soybean lipoxygenase-1 (LOX-1) was studied using linoleic acid as the substrate. The enzyme was competitively inhibited by TRIA. The Ki for TRIA inhibition of the enzyme was estimated to be 3.2-5.0 microM according to different methods of estimation. TRIA has been known to exhibit anti-inflammatory action in animals and this anti-inflammatory effect of TRIA might be mediated through inhibition of lipid peroxidation. Since LOX inhibitors have been extensively used as therapeutic agents, TRIA, being a natural compound has been suggested to be an effective anti-inflammatory drug.

  8. Retrieval-Induced Inhibition in Short-Term Memory.

    Science.gov (United States)

    Kang, Min-Suk; Choi, Joongrul

    2015-07-01

    We used a visual illusion called motion repulsion as a model system for investigating competition between two mental representations. Subjects were asked to remember two random-dot-motion displays presented in sequence and then to report the motion directions for each. Remembered motion directions were shifted away from the actual motion directions, an effect similar to the motion repulsion observed during perception. More important, the item retrieved second showed greater repulsion than the item retrieved first. This suggests that earlier retrieval exerted greater inhibition on the other item being held in short-term memory. This retrieval-induced motion repulsion could be explained neither by reduced cognitive resources for maintaining short-term memory nor by continued inhibition between short-term memory representations. These results indicate that retrieval of memory representations inhibits other representations in short-term memory. We discuss mechanisms of retrieval-induced inhibition and their implications for the structure of memory. © The Author(s) 2015.

  9. Inhibition of telomerase activity and cell growth by free and ...

    African Journals Online (AJOL)

    Furthermore, the telomerase activity of the nanoliposomal punicalagin-treated cells was significantly inhibited in a time- and dose-dependent manner. Conclusion: Punicalagin shows a novel mechanism of anti-telomerase activity, particularly in the nanoliposomal form, and may provide a basis for the future development of ...

  10. Latent Inhibition in an Insect: The Role of Aminergic Signaling

    Science.gov (United States)

    Fernandez, Vanesa M.; Giurfa, Martin; Devaud, Jean-Marc; Farina, Walter M.

    2012-01-01

    Latent inhibition (LI) is a decrement in learning performance that results from the nonreinforced pre-exposure of the to-be-conditioned stimulus, in both vertebrates and invertebrates. In vertebrates, LI development involves dopamine and serotonin; in invertebrates there is yet no information. We studied differential olfactory conditioning of the…

  11. Inhibition of beet molasses alcoholic fermentation by lactobacilli

    Energy Technology Data Exchange (ETDEWEB)

    Essia Ngang, J.J.; Letourneau, F.; Wolniewicz, E.; Villa, P. (Amiens Univ., 80 (France). Lab. de Chimie Organique et Cinetique)

    1990-08-01

    Alcohol production rate decreases as the concentration of bacterial contaminants increases. In complex medium, such as beet molasses, an alternative mechanism can be used by homofermentative lactic bacteria (Lactobacillus casei). Lactic acid and associated products, especially acetic acid, are liberated into the medium. The inhibition induced by these metabolites was reinforced by the presence of viable lactobacilli. (orig.).

  12. Inhibition of human lung adenocarcinoma growth using survivint34a ...

    Indian Academy of Sciences (India)

    Low-dose systemic administration was continuously used. The HSurvivinT34A plasmid (5 g/one) complexed with a cationic liposome (DOTAP/Chol) significantly inhibited tumour growth in our model. We observed microvessel density degradation by CD31 immunohistochemistry and apoptotic cell increase by TUNEL ...

  13. Inhibition of pneumococcal autolysis in lysis-centrifugation blood culture.

    OpenAIRE

    Lehtonen, O P

    1986-01-01

    The recovery of Streptococcus pneumoniae from the Isolator lysis-centrifugation blood culture has been low in many studies. The poor survival of pneumococci was not due to toxicity of the Isolator medium but to autolysis before plating. This autolysis was completely inhibited by adding 10 mM phosphorylcholine to the Isolator medium.

  14. Zinc-mediated Allosteric Inhibition of Caspase-6*

    Science.gov (United States)

    Velázquez-Delgado, Elih M.; Hardy, Jeanne A.

    2012-01-01

    Zinc and caspase-6 have independently been implicated in several neurodegenerative disorders. Depletion of zinc intracellularly leads to apoptosis by an unknown mechanism. Zinc inhibits cysteine proteases, including the apoptotic caspases, leading to the hypothesis that zinc-mediated inhibition of caspase-6 might contribute to its regulation in a neurodegenerative context. Using inductively coupled plasma optical emission spectroscopy, we observed that caspase-6 binds one zinc per monomer, under the same conditions where the zinc leads to complete loss of enzymatic activity. To understand the molecular details of zinc binding and inhibition, we performed an anomalous diffraction experiment above the zinc edge. The anomalous difference maps showed strong 5σ peaks, indicating the presence of one zinc/monomer bound at an exosite distal from the active site. Zinc was not observed bound to the active site. The zinc in the exosite was liganded by Lys-36, Glu-244, and His-287 with a water molecule serving as the fourth ligand, forming a distorted tetrahedral ligation sphere. This exosite appears to be unique to caspase-6, as the residues involved in zinc binding were not conserved across the caspase family. Our data suggest that binding of zinc at the exosite is the primary route of inhibition, potentially locking caspase-6 into the inactive helical conformation. PMID:22891250

  15. Recurrent angioedema associated with pharmacological inhibition of dipeptidyl peptidase IV

    DEFF Research Database (Denmark)

    Hermanrud, Thorbjørn; Bygum, Anette; Rasmussen, Eva Rye

    2017-01-01

    -converting enzyme inhibitors (ACEI-AAE) is well known, but other pharmaceutical agents also affect the degradation of bradykinin and substance P. We present a middle-aged man with recurrent episodes of severe AE of the oral cavity, hypopharynx and larynx due to pharmacological inhibition of dipeptidyl peptidase IV....

  16. Self-inhibiting growth of the Greenland Ice Sheet

    DEFF Research Database (Denmark)

    Langen, Peter Lang; Solgaard, Anne Munck; Hvidberg, Christine Schøtt

    2012-01-01

    -line are augmented by one where an intermediate ice sheet configuration is coupled back to the GCM. Forcing the ISM with GCM fields corresponding to the ice-free state leads to extensive regrowth which, however, is halted when the intermediate recoupling step is included. This inhibition of further growth is due...

  17. Inhibition of Bio corrosion of steel coupon by sulphate reducing ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT; The inhibition of biocorrosion of steel coupons by sulphate reducing bacteria (SRB) and Iron oxidizing bacteria (IOB) using Aloe vera (Aloe barbadensis) extract was tested. The water sample revealed a heterotrophic bacterial count of 1.7x103 cfu/ml for the sulphate reducing bacteria and 4.1x103 cfu/ml for the ...

  18. Experimental and quantum chemical studies on corrosion inhibition ...

    Indian Academy of Sciences (India)

    The results showed that FLU can act as a good cor- rosion inhibitor for steel in hydrochloric acid solution at different temperatures and it can inhibit steel corrosion up to 95%. The adsorption followed the Langmuir isotherm and the thermodynamic parameters were also determined and discussed. Quantum chemical studies ...

  19. Phosphate inhibition on thermophilic acetoclastic methanogens: a warning

    NARCIS (Netherlands)

    Paulo, P.L.; Santos, dos A.B.; Ide, C.N.; Lettinga, G.

    2005-01-01

    The inhibitory effect of phosphate on acetoclastic-methanogens was investigated for three different thermophilic (55 degrees C) anaerobic consortia. When 70 mM of phosphate was tested, acetoclastic methanogens was completely inhibited in "Eerbeek" sludge which is dominated by Methanosaeta-like

  20. Central Inhibition Ability Modulates Attention-Induced Motion Blindness

    Science.gov (United States)

    Milders, Maarten; Hay, Julia; Sahraie, Arash; Niedeggen, Michael

    2004-01-01

    Impaired motion perception can be induced in normal observers in a rapid serial visual presentation task. Essential for this effect is the presence of motion distractors prior to the motion target, and we proposed that this attention-induced motion blindness results from high-level inhibition produced by the distractors. To investigate this, we…

  1. Glabridin from Chinese herb licorice inhibits fatigue in mice | Shang ...

    African Journals Online (AJOL)

    Body mass, blood lactic acid (BLA), serum blood urea nitrogen (BUN), liver glycogen and muscle glycogen concentrations in mice were determined. Results showed that glabridin significantly inhibited fatigue, which extended the exhaustive exercise time of mice, effectively delayed the elevation of blood lactic acid and ...

  2. The antiproteinuric effect of ace inhibition in renal disease

    NARCIS (Netherlands)

    Heeg, J.E.

    1992-01-01

    In 1985 some studies were published showing that angiotensin converting enzyme (ACE) inhibition not only reduced the elevated blood pressure in animals with chronic renal failure (experimentally induced by renal ablation or by induced diabetic nephropathy), but also prevented the development of

  3. Restriction Inhibition Assay: A Qualitative and Quantitative Method to ...

    African Journals Online (AJOL)

    rich fractions (PRFs) with high affinity for EcoRI and HindIII restriction sequences and correlate their interaction to an anticancer activity. Methods: pBR322 linear plasmid DNA was used as a template to screen the sequence-selective inhibition of ...

  4. DNA damage protection and 5-lipoxygenase inhibiting activity of ...

    African Journals Online (AJOL)

    DNA damage caused by free radical is associated with mutation-based health impairment. The protective effect on DNA damage mediated by hydroxyl radical and peroxynitrite radical, and the inhibiting activity on 5-lipoxygenase of areca inflorescence extracts were studied in vitro. The results show that the boiling water ...

  5. Larvicidal and adult emergence inhibition effect of Centella asiatica ...

    African Journals Online (AJOL)

    Ethanolic extract of Centella asiatica leaves were evaluated for the larvicidal and adult emergence inhibition activity against mosquito Culex quinquefasciatus under five constant temperatures 19, 22, 25, 28 and 31°C in the laboratory. Toxicity of this extract increased with temperature. The 50% medium lethal concentrations ...

  6. Inhibition of Estradiol Synthesis Impairs Fear Extinction in Male Rats

    Science.gov (United States)

    Graham, Bronwyn M.; Milad, Mohammed R.

    2014-01-01

    Emerging research has demonstrated that the sex hormone estradiol regulates fear extinction in female rodents and women. Estradiol may also regulate fear extinction in males, given its role in synaptic plasticity in both sexes. Here we report that inhibition of estradiol synthesis during extinction training, via the aromatase inhibitor fadrozole,…

  7. Grain coarsening of calcite: Fundamental mechanisms and biogenic inhibition

    DEFF Research Database (Denmark)

    Schultz, Logan Nicholas

    coarsening – small grains coarsen by aggregation at high temperatures, followed by Ostwald ripening. Alginate, a model for the acidic polysaccharides produced by coccolithiphores, inhibited coarsening at a steady rate. A Pseudomonas aeruginosa biofilm preserved particles for at least 60 days before...

  8. Inhibition of Sheep Liver Cholinesterase Enzyme by the Leaf ...

    African Journals Online (AJOL)

    The efficacies of these crude extract were comparable to that of Huperzine A as a reference standard for cholinesterase inhibition. The anticholinesterase assay serves as an indicator system whose analysis always correspond to the bioluminescent Mycobacterium aurum or tuberculosis expressing firefly luciferase.

  9. Research on sprout inhibition effect of refrigerated garlic by irradiation

    International Nuclear Information System (INIS)

    Zhang Xuan; He Jianzhong; Li Ruijun

    2005-01-01

    This paper researches the sprout inhibition effect by irradiation on refrigerated garlic. The results shows that, the garlic is still in the period of dormancy within 7 days after taken out from the refrigerated warehouse, and irradiation have a good sprout inhibition effect on it. The irradiation dose is 40-90 Gy, the same as that of the post harvest irradiation treatment on garlic. Refrigerate the Zhongmu Garlic (at -2 degree C-0 degree C) until the middle ten days of February the next year, place it at the room temperature (10 degree C-15 degree C) for 1-7 days after taking it out of the warehouse, then use 60 Co γ-ray to irradiate it until the absorbed dose reaches 40-90 Gy, the sprout inhibition effect can be realized. The test also indicates that the deposited time after taking out of the refrigerated warehouse is crucial to the sprout inhibition effect of refrigerated garlic by irradiation. (authors)

  10. Gas hydrate inhibition by perturbation of liquid water structure.

    Science.gov (United States)

    Sa, Jeong-Hoon; Kwak, Gye-Hoon; Han, Kunwoo; Ahn, Docheon; Lee, Kun-Hong

    2015-06-17

    Natural gas hydrates are icy crystalline materials that contain hydrocarbons, which are the primary energy source for this civilization. The abundance of naturally occurring gas hydrates leads to a growing interest in exploitation. Despite their potential as energy resources and in industrial applications, there is insufficient understanding of hydrate kinetics, which hinders the utilization of these invaluable resources. Perturbation of liquid water structure by solutes has been proposed to be a key process in hydrate inhibition, but this hypothesis remains unproven. Here, we report the direct observation of the perturbation of the liquid water structure induced by amino acids using polarized Raman spectroscopy, and its influence on gas hydrate nucleation and growth kinetics. Amino acids with hydrophilic and/or electrically charged side chains disrupted the water structure and thus provided effective hydrate inhibition. The strong correlation between the extent of perturbation by amino acids and their inhibition performance constitutes convincing evidence for the perturbation inhibition mechanism. The present findings bring the practical applications of gas hydrates significantly closer, and provide a new perspective on the freezing and melting phenomena of naturally occurring gas hydrates.

  11. Inhibition and Kinetic Studies of Tortoise (Kinixys erosa) Liver arginase

    African Journals Online (AJOL)

    The effect of amino acid on tortoise liver arginase showed that L-lysine, L-valine, L-serine, L-aspartic acid and L aspartic acid had significant inhibitory effect on the enzyme but proline and glutamic acid showed slight inhibition. Ethylenediaminetetraacetic acid (EDTA), citrate, ascorbic acid, boric acid and sodium borate ...

  12. The neural markers of an imminent failure of response inhibition

    NARCIS (Netherlands)

    Bengson, Jesse J.; Mangun, George R.; Mazaheri, Ali

    2012-01-01

    In his novel Ulysses, James Joyce wrote that mistakes are the "...portals of discovery". The present study investigated the pre-stimulus oscillatory EEG signatures of selective attention and motor preparation that predicted failures of overt response inhibition. We employed a trial-by-trial spatial

  13. Inhibition of histone deacetylase activity by valproic acid blocks adipogenesis.

    Science.gov (United States)

    Lagace, Diane C; Nachtigal, Mark W

    2004-04-30

    Adipogenesis is dependent on the sequential activation of transcription factors including the CCAAT/enhancer-binding proteins (C/EBP), peroxisome proliferator-activated receptor gamma (PPARgamma), and steroid regulatory element-binding protein (SREBP). We show that the mood stabilizing drug valproic acid (VPA; 0.5-2 mm) inhibits mouse 3T3 L1 and human preadipocyte differentiation, likely through its histone deacetylase (HDAC) inhibitory properties. The HDAC inhibitor trichostatin A (TSA) also inhibited adipogenesis, whereas the VPA analog valpromide, which does not possess HDAC inhibitory effects, did not prevent adipogenesis. Acute or chronic VPA treatment inhibited differentiation yet did not affect mitotic clonal expansion. VPA (1 mm) inhibited PPARgamma induced differentiation but does not activate a PPARgamma reporter gene, suggesting that it is not a PPARgamma ligand. VPA or TSA treatment reduced mRNA and protein levels of PPARgamma and SREBP1a. TSA reduced C/EBPalpha mRNA and protein levels, whereas VPA only produced a decrease in C/EBPalpha protein expression. Overall our results highlight a role for HDAC activity in adipogenesis that can be blocked by treatment with VPA.

  14. DNA methyltransferase inhibitor CDA-II inhibits myogenic differentiation

    International Nuclear Information System (INIS)

    Chen, Zirong; Jin, Guorong; Lin, Shuibin; Lin, Xiumei; Gu, Yumei; Zhu, Yujuan; Hu, Chengbin; Zhang, Qingjiong; Wu, Lizi; Shen, Huangxuan

    2012-01-01

    Highlights: ► CDA-II inhibits myogenic differentiation in a dose-dependent manner. ► CDA-II repressed expression of muscle transcription factors and structural proteins. ► CDA-II inhibited proliferation and migration of C2C12 myoblasts. -- Abstract: CDA-II (cell differentiation agent II), isolated from healthy human urine, is a DNA methyltransferase inhibitor. Previous studies indicated that CDA-II played important roles in the regulation of cell growth and certain differentiation processes. However, it has not been determined whether CDA-II affects skeletal myogenesis. In this study, we investigated effects of CDA-II treatment on skeletal muscle progenitor cell differentiation, migration and proliferation. We found that CDA-II blocked differentiation of murine myoblasts C2C12 in a dose-dependent manner. CDA-II repressed expression of muscle transcription factors, such as Myogenin and Mef2c, and structural proteins, such as myosin heavy chain (Myh3), light chain (Mylpf) and MCK. Moreover, CDA-II inhibited C1C12 cell migration and proliferation. Thus, our data provide the first evidence that CDA-II inhibits growth and differentiation of muscle progenitor cells, suggesting that the use of CDA-II might affect skeletal muscle functions.

  15. Inhibiting Aspergillus flavus growth and degrading aflatoxin B1 by ...

    African Journals Online (AJOL)

    Aflatoxin B1 (AFB1) is a type of toxin produced by Aspergillus flavus, which has a negative effect on animal production and economic profits. In order to inhibit A. flavus growth and degrade aflatoxin, the optimal proportion of beneficial microbes such as Lactobacillus casei, Bacillus subtilis and Pichia anomala were selected.

  16. Inhibition of growth and mycotoxins formation in moulds by marine ...

    African Journals Online (AJOL)

    Administrator

    methanolic extract for all strains. This may complement the explanation of the hypothesis developed for the ethanolic extract, which may suggest that the partial inhibition is due to a partial extraction of the active compounds, which are more extractable, by ethanol than by methanol. This is only broadly studied on the crude.

  17. Inhibition of auxin-induced ethylene production by lycoricidinol

    International Nuclear Information System (INIS)

    Kang, Bin-G.; Lee, June-S.; Oh, Seung-Eun; Horiuchi, Yuko; Imaseki, Hidemasa.

    1984-01-01

    Lycoricidinol, a natural growth inhibitor isolated from bulbs of Lycoris radiata Herb. strongly suppressed auxin-induced ethylene production from the hypocotyl segments of etiolated mung bean (Vigna radiata Wilczek) seedlings. The inhibitor did not significantly inhibit ethylene formation from its immediate precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), during short-term (up to 4h) incubation. The ACC content in tissue treated with IAA was reduced by lycoricidinol in close parallel with the inhibition of ethylene production. Examination of radioactive metabolites in tissues labeled with 3,4- 14 C-methionine indicated that reduction of the ACC content was not due to any possible promotive effect of lycoricidinol on conjugation of ACC with malonate. Lycoricidinol showed no inhibitory effect on the activity of ACC synthase if applied in vitro, but it almost completely abolished the increase in the enzyme activity when applied in vivo during incubation of the tissue with IAA. Lycoricidinol also strongly inhibited incorporation of 14 C-leucine into protein in the tissue. The suppression of the enzyme induction and, in turn, that of ethylene production by lycoricidinol were interpreted as being due to the inhibition of protein synthesis. (author)

  18. Novel Approaches to Breast Cancer Prevention and Inhibition of Metastases

    Science.gov (United States)

    2014-10-01

    TSPAN6 mRNA is expressed in multiple tissues including kidney, liver, thyroid, prostate, pancreas, uterus, testis, salivary and adrenal glands , or smooth......2013 – 29 Sep 2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Novel Approaches to Breast Cancer Prevention and Inhibition of Metastases 5b

  19. Curcumin Enhances Bortezomib Treatment of Myeloma by Inhibiting ...

    African Journals Online (AJOL)

    Purpose: To investigate whether curcumin augments bortezomib-induced apoptosis in myeloma cells (MM1.R line), and to explore the molecular mechanism with regard to heat shock protein 90 (HSP90) expression. Methods: MTT cell viability assay was used to assess growth inhibition of MM1.R cells at different ...

  20. Inhibition of coagulation factors by recombinant barley serpin BSZx

    DEFF Research Database (Denmark)

    Dahl, Søren Weis; Rasmussen, S.K.; Petersen, L..C.

    1996-01-01

    and leukocytes, a fungal trypsin and three subtilisins, Thrombin, plasma kallikrein, factor VIIa/tissue factor and factor Xa were inhibited by BSZx at heparin independent association rates (k(ass)) of 4.5 x 10(3)-1.3 x 10(5) M(-1) s(-1) at 22 degrees C. Only factor Xa turned a significant fraction of BSZx over...