Olive oil compounds inhibit vascular endothelial growth factor receptor-2 phosphorylation

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Lamy, Sylvie; Ouanouki, Amira; Béliveau, Richard; Desrosiers, Richard R.

2014-01-01

Vascular endothelial growth factor (VEGF) triggers crucial signaling processes that regulate tumor angiogenesis and, therefore, represents an attractive target for the development of novel anticancer therapeutics. Several epidemiological studies have confirmed that abundant consumption of foods from plant origin is associated with reduced risk of developing cancers. In the Mediterranean basin, the consumption of extra virgin olive oil is an important constituent of the diet. Compared to other vegetable oils, the presence of several phenolic antioxidants in olive oil is believed to prevent the occurrence of a variety of pathological processes, such as cancer. While the strong antioxidant potential of these molecules is well characterized, their antiangiogenic activities remain unknown. The aim of this study is to investigate whether tyrosol (Tyr), hydroxytyrosol (HT), taxifolin (Tax), oleuropein (OL) and oleic acid (OA), five compounds contained in extra virgin olive oil, can affect in vitro angiogenesis. We found that HT, Tax and OA were the most potent angiogenesis inhibitors through their inhibitory effect on specific autophosphorylation sites of VEGFR-2 (Tyr951, Tyr1059, Tyr1175 and Tyr1214) leading to the inhibition of endothelial cell (EC) signaling. Inhibition of VEGFR-2 by these olive oil compounds significantly reduced VEGF-induced EC proliferation and migration as well as their morphogenic differentiation into capillary-like tubular structures in Matrigel. Our study demonstrates that HT, Tax and OA are novel and potent inhibitors of the VEGFR-2 signaling pathway. These findings emphasize the chemopreventive properties of olive oil and highlight the importance of nutrition in cancer prevention. - Highlights: • We investigated five compounds contained in extra virgin olive oil on angiogenesis. • Hydroxytyrosol, taxifolin and oleic acid are the best angiogenesis inhibitors. • Olive oil compounds affect endothelial cell functions essential for

Olive oil compounds inhibit vascular endothelial growth factor receptor-2 phosphorylation

Energy Technology Data Exchange (ETDEWEB)

Lamy, Sylvie, E-mail: lamy.sylvie@uqam.ca; Ouanouki, Amira; Béliveau, Richard; Desrosiers, Richard R.

2014-03-10

Vascular endothelial growth factor (VEGF) triggers crucial signaling processes that regulate tumor angiogenesis and, therefore, represents an attractive target for the development of novel anticancer therapeutics. Several epidemiological studies have confirmed that abundant consumption of foods from plant origin is associated with reduced risk of developing cancers. In the Mediterranean basin, the consumption of extra virgin olive oil is an important constituent of the diet. Compared to other vegetable oils, the presence of several phenolic antioxidants in olive oil is believed to prevent the occurrence of a variety of pathological processes, such as cancer. While the strong antioxidant potential of these molecules is well characterized, their antiangiogenic activities remain unknown. The aim of this study is to investigate whether tyrosol (Tyr), hydroxytyrosol (HT), taxifolin (Tax), oleuropein (OL) and oleic acid (OA), five compounds contained in extra virgin olive oil, can affect in vitro angiogenesis. We found that HT, Tax and OA were the most potent angiogenesis inhibitors through their inhibitory effect on specific autophosphorylation sites of VEGFR-2 (Tyr951, Tyr1059, Tyr1175 and Tyr1214) leading to the inhibition of endothelial cell (EC) signaling. Inhibition of VEGFR-2 by these olive oil compounds significantly reduced VEGF-induced EC proliferation and migration as well as their morphogenic differentiation into capillary-like tubular structures in Matrigel. Our study demonstrates that HT, Tax and OA are novel and potent inhibitors of the VEGFR-2 signaling pathway. These findings emphasize the chemopreventive properties of olive oil and highlight the importance of nutrition in cancer prevention. - Highlights: • We investigated five compounds contained in extra virgin olive oil on angiogenesis. • Hydroxytyrosol, taxifolin and oleic acid are the best angiogenesis inhibitors. • Olive oil compounds affect endothelial cell functions essential for

Heterogeneous inhibition of the liquid phase oxidation of hydrocarbons by molybdenum compounds

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Tavadyan, L.A.; Karapetyan, A.P.; Madatovyan, V.M.

1988-05-01

The heterogeneous action of molybdenum compounds: MoB, MoSe/sub 2/, MoSi/sub 2/, Mo/sub 2/C, MoO/sub 3/, Mo on the oxidation of n-decane, ethylbenzene, and nonene-1 has been investigated. A parameter representing the inhibiting effect of the heterogeneous catalyst was calculated theoretically. It was found that NoB, MoSe/sub 2/, and MoSi/sub 2/ inhibited the oxidation of n-decane at 408 K while the remaining heterogeneous contacts catalyzed it. A critical phenomenon was detected in the inhibition by MoSi/sub 2/. All the molybdenum compounds investigated inhibited the oxidation of ethylbenzene at 393 K owing to the formation of phenol by catalytic decomposition of the hydroperoxide. The liquid phase oxidation autoinhibited by phenol is described theoretically.

Dihydrochalcone Compounds Isolated from Crabapple Leaves Showed Anticancer Effects on Human Cancer Cell Lines

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Xiaoxiao Qin

2015-11-01

Full Text Available Seven dihydrochalcone compounds were isolated from the leaves of Malus crabapples, cv. “Radiant”, and their chemical structures were elucidated by UV, IR, ESI-MS, 1H-NMR and 13C-NMR analyses. These compounds, which include trilobatin (A1, phloretin (A2, 3-hydroxyphloretin (A3, phloretin rutinoside (A4, phlorizin (A5, 6′′-O-coumaroyl-4′-O-glucopyranosylphloretin (A6, and 3′′′-methoxy-6′′-O-feruloy-4′-O-glucopyranosyl-phloretin (A7, all belong to the phloretin class and its derivatives. Compounds A6 and A7 are two new rare dihydrochalcone compounds. The results of a MTT cancer cell growth inhibition assay demonstrated that phloretin and these derivatives showed significant positive anticancer activities against several human cancer cell lines, including the A549 human lung cancer cell line, Bel 7402 liver cancer cell line, HepG2 human ileocecal cancer cell line, and HT-29 human colon cancer cell line. A7 had significant effects on all cancer cell lines, suggesting potential applications for phloretin and its derivatives. Adding a methoxyl group to phloretin dramatically increases phloretin’s anticancer activity.

Isolation and identification of compounds from Kalanchoe pinnata having human alphaherpesvirus and vaccinia virus antiviral activity.

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Cryer, Matthew; Lane, Kyle; Greer, Mary; Cates, Rex; Burt, Scott; Andrus, Merritt; Zou, Jiping; Rogers, Paul; Hansen, Marc D H; Burgado, Jillybeth; Panayampalli, Subbian Satheshkumar; Day, Craig W; Smee, Donald F; Johnson, Brent F

2017-12-01

Kalanchoe pinnata (Lam.) Pers. (Crassulaceae) is a succulent plant that is known for its traditional antivirus and antibacterial usage. This work examines two compounds identified from the K. pinnata plant for their antivirus activity against human alphaherpesvirus (HHV) 1 and 2 and vaccinia virus (VACV). Compounds KPB-100 and KPB-200 were isolated using HPLC and were identified using NMR and MS. Both compounds were tested in plaque reduction assay of HHV-2 wild type (WT) and VACV. Both compounds were then tested in virus spread inhibition and virus yield reduction (VYR) assays of VACV. KPB-100 was further tested in viral cytopathic effect (CPE) inhibition assay of HHV-2 TK-mutant and VYR assay of HHV-1 WT. KPB-100 and KPB-200 inhibited HHV-2 at IC 50 values of 2.5 and 2.9 μg/mL, respectively, and VACV at IC 50 values of 3.1 and 7.4 μg/mL, respectively, in plaque reduction assays. In virus spread inhibition assay of VACV KPB-100 and KPB-200 yielded IC 50 values of 1.63 and 13.2 μg/mL, respectively, and KPB-100 showed a nearly 2-log reduction in virus in VYR assay of VACV at 20 μg/mL. Finally, KPB-100 inhibited HHV-2 TK- at an IC 50 value of 4.5 μg/mL in CPE inhibition assay and HHV-1 at an IC 90 of 3.0 μg/mL in VYR assay. Both compounds are promising targets for synthetic optimization and in vivo study. KPB-100 in particular showed strong inhibition of all viruses tested.

Corrosion inhibition properties of pyrazolylindolenine compounds on copper surface in acidic media

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Ebadi Mehdi

2012-12-01

Full Text Available Abstract Background The corrosion inhibition performance of pyrazolylindolenine compounds, namely 4-(3,3-dimethyl-3H-indol-2-yl-pyrazole-1-carbothioamide (InPzTAm, 4-(3,3-dimethyl-3H-indol-2-yl-1H-pyrazole-1-carbothiohydrazide (InPzTH and 3,3-dimethyl-2-(1-phenyl-1H-pyrazol-4-yl-3H-indole (InPzPh, on copper in 1M HCl solution is investigated by electrochemical impedance spectroscopy (EIS, open circuit potential (OCP and linear scan voltammetry (LSV techniques. Results The results show that the corrosion rate of copper is diminished by the compounds with the inhibition strength in the order of: InPzTAm> InPzTH > InPzPh. The corrosion inhibition efficiencies for the three inhibitors are 94.0, 91.4 and 79.3, for InPzTAm, InPzTH and InPzPh respectively with the same inhibitor concentration (2 mM. Conclusion From the EIS, OCP and LSV results it was concluded that pyrazolylindolenine compounds with S-atom (with an amine group have illustrated better corrosion inhibition performance compared to hydrazine and phenyl group.

Bioassay-Guided Isolated Compounds from Morinda officinalis Inhibit Alzheimer’s Disease Pathologies

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Yoon Kyoung Lee

2017-09-01

Full Text Available Due to the side effects of synthetic drugs, the therapeutic potential of natural products for Alzheimer’s disease (AD has gained interest. Morinda officinalis has demonstrated inhibitory effects on geriatric diseases, such as bone loss and osteoporosis. However, although AD is a geriatric disease, M. officinalis has not been evaluated in an AD bioassay. Therefore, M. officinalis extracts and fractions were tested for AD-related activity, including inhibition of acetylcholinesterase (AChE, butyrylcholinesterase (BChE, β-site amyloid precursor protein cleaving enzyme 1 (BACE1, and advanced glycation end-product (AGE formation. A bioassay-guided approach led to isolation of 10 active compounds, eight anthraquinones (1–8, one coumarin (9, and one phytosterol (10, from n-hexane and ethyl acetate fractions of M. officinalis. The five anthraquinones (4–8 were stronger inhibitors of AChE than were other compounds. Compounds 3 and 9 were good inhibitors of BChE, and compounds 3 and 8 were good inhibitors of BACE1. Compounds 1–5 and 7–9 were more active than the positive control in inhibiting AGE formation. In addition, we first suggested a structure-activity relationship by which anthraquinones inhibit AChE and BACE1. Our findings demonstrate the preventive and therapeutic efficacy of M. officinalis for AD and its potential use as a natural alternative medicine.

Development of an Intracellular Screen for New Compounds Able To Inhibit Mycobacterium tuberculosis Growth in Human Macrophages.

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Sorrentino, Flavia; Gonzalez del Rio, Ruben; Zheng, Xingji; Presa Matilla, Jesus; Torres Gomez, Pedro; Martinez Hoyos, Maria; Perez Herran, Maria Esther; Mendoza Losana, Alfonso; Av-Gay, Yossef

2016-01-01

Here we describe the development and validation of an intracellular high-throughput screening assay for finding new antituberculosis compounds active in human macrophages. The assay consists of a luciferase-based primary identification assay, followed by a green fluorescent protein-based secondary profiling assay. Standard tuberculosis drugs and 158 previously recognized active antimycobacterial compounds were used to evaluate assay robustness. Data show that the assay developed is a short and valuable tool for the discovery of new antimycobacterial compounds. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Corrosion inhibition of carbon steel in acidic medium by orange peel extract and its main antioxidant compounds

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M’hiri, Nouha; Veys-Renaux, Delphine; Rocca, Emmanuel; Ioannou, Irina; Boudhrioua, Nourhéne Mihoubi; Ghoul, Mohamed

2016-01-01

Highlights: • Catechol and derived functions are responsible for flavonoids antioxidant activity. • Antioxidant activity of adsorbed molecules explains cathodic inhibition. • Orange peel extract inhibition is enhanced by the precipitation of a covering film. - Abstract: Chemical compounds of orange peel extracts were identified and their antioxidant activities were determined. The inhibiting effect on acidic steel corrosion brought by the extract and selected antioxidant compounds (neohesperidin, naringin, ascorbic acid) was evaluated separately by electrochemical methods. Whatever the extract concentration, a significant inhibition is observed, whereas selected antioxidant compounds show only a slight effect. Both electrochemical impedance spectroscopy results and scanning electron microscopy observations after immersion reveal that the inhibiting efficiency of orange peel extract is not only due to the antioxidant activity of its compounds but also to the precipitation of a surface film.

Inhibition of lignin-derived phenolic compounds to cellulase.

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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

Compound C inhibits macrophage chemotaxis through an AMPK-independent mechanism

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Lee, Youngyi [College of Pharmacy, Woosuk University, Wanju, Jeonbuk 55338 (Korea, Republic of); Department of Biochemistry, Chonbuk National University Medical School, Jeonju, Jeonbuk 54896 (Korea, Republic of); Park, Byung-Hyun, E-mail: bhpark@jbnu.ac.kr [Department of Biochemistry, Chonbuk National University Medical School, Jeonju, Jeonbuk 54896 (Korea, Republic of); Bae, Eun Ju, E-mail: ejbae@woosuk.ac.kr [College of Pharmacy, Woosuk University, Wanju, Jeonbuk 55338 (Korea, Republic of)

2016-01-15

Macrophage infiltration in adipose tissue is a well-established cause of obesity-linked insulin resistance. AMP-activated protein kinase (AMPK) activation in peripheral tissues such as adipose tissue has beneficial effects on the protection against obesity-induced insulin resistance, which is mainly mediated by prevention of adipose tissue macrophage infiltration and inflammation. In examining the role of AMPK on adipose tissue inflammation, we unexpectedly found that compound C (CC), despite its inhibition of AMPK, robustly inhibited macrophage chemotaxis in RAW 264.7 cells when adipocyte conditioned medium (CM) was used as a chemoattractant. Here, we report that CC inhibition of macrophage migration occurred independently of AMPK. Mechanistically, this inhibitory effect of cell migration by CC was mediated by inhibition of the focal adhesion kinase, AKT, nuclear factor κB pathways. Moreover, the expression of chemokine monocyte chemoattractant protein-1 and pro-inflammatory genes such as tumor necrosis factor α and inducible nitric oxide synthase were prevented by CC treatment in RAW 264.7 cells stimulated with either adipocyte CM or lipopolysaccharide. Lastly, in accord with the findings of the anti-inflammatory effect of CC, we demonstrated that CC functioned as a repressor of macrophage CM-mediated insulin resistance in adipocytes. Taken together, our results suggest that CC serves as a useful inhibitory molecule against macrophage chemotaxis into adipose tissue and thus might have therapeutic potential for the treatment of obesity-linked adipose inflammation. - Highlights: • Compound C (CC) inhibits macrophage chemotaxis regardless of AMPK suppression. • CC enhances insulin sensitivity in adipocytes. • CC inhibits focal adhesion kinase, AKT, and NF-κB signaling in RAW 264.7 cells.

Efficacy of an antiviral compound to inhibit replication of multiple pestivirus species.

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Newcomer, Benjamin W; Marley, M Shonda; Ridpath, Julia F; Neill, John D; Boykin, David W; Kumar, Arvind; Givens, M Daniel

2012-11-01

Pestiviruses are economically important pathogens of livestock. An aromatic cationic compound (DB772) has previously been shown to inhibit bovine viral diarrhea virus (BVDV) type 1 in vitro at concentrations lacking cytotoxic side effects. The aim of this study was to determine the scope of antiviral activity of DB772 among diverse pestiviruses. Isolates of BVDV 2, border disease virus (BDV), HoBi virus, pronghorn virus and Bungowannah virus were tested for in vitro susceptibility to DB772 by incubating infected cells in medium containing 0, 0.006, 0.01, 0.02, 0.05, 0.1, 0.2, 0.39, 0.78, 1.56, 3.125, 6.25, 12.5 or 25μM DB772. The samples were assayed for the presence of virus by virus isolation and titration (BDV and BVDV 2) or PCR (HoBi, pronghorn and Bungowannah viruses). Cytotoxicity of the compound was assayed for each cell type. Complete inhibition of BVDV 2, BDV, and Pronghorn virus was detected when DB772 was included in the culture media at concentrations of 0.20μM and higher. In two of three tests, a concentration of 0.05μM DB772 was sufficient to completely inhibit HoBi virus replication. Bungowannah virus was completely inhibited at a concentration of 0.01μM DB772. Thus, DB772 effectively inhibits all pestiviruses studied at concentrations >0.20μM. As cytotoxicity is not evident at these concentrations, this antiviral compound potentially represents an effective preventative or therapeutic for diverse pestiviruses. Copyright © 2012 Elsevier B.V. All rights reserved.

Spice phenolics inhibit human PMNL 5-lipoxygenase.

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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.

Mechanism of inhibition of human secretory phospholipase A2 by flavonoids: rationale for lead design

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Lättig, Jens; Böhl, Markus; Fischer, Petra; Tischer, Sandra; Tietböhl, Claudia; Menschikowski, Mario; Gutzeit, Herwig O.; Metz, Peter; Pisabarro, M. Teresa

2007-08-01

The human secretory phospholipase A2 group IIA (PLA2-IIA) is a lipolytic enzyme. Its inhibition leads to a decrease in eicosanoids levels and, thereby, to reduced inflammation. Therefore, PLA2-IIA is of high pharmacological interest in treatment of chronic diseases such as asthma and rheumatoid arthritis. Quercetin and naringenin, amongst other flavonoids, are known for their anti-inflammatory activity by modulation of enzymes of the arachidonic acid cascade. However, the mechanism by which flavonoids inhibit Phospholipase A2 (PLA2) remained unclear so far. Flavonoids are widely produced in plant tissues and, thereby, suitable targets for pharmaceutical extractions and chemical syntheses. Our work focuses on understanding the binding modes of flavonoids to PLA2, their inhibition mechanism and the rationale to modify them to obtain potent and specific inhibitors. Our computational and experimental studies focused on a set of 24 compounds including natural flavonoids and naringenin-based derivatives. Experimental results on PLA2-inhibition showed good inhibitory activity for quercetin, kaempferol, and galangin, but relatively poor for naringenin. Several naringenin derivatives were synthesized and tested for affinity and inhibitory activity improvement. 6-(1,1-dimethylallyl)naringenin revealed comparable PLA2 inhibition to quercetin-like compounds. We characterized the binding mode of these compounds and the determinants for their affinity, selectivity, and inhibitory potency. Based on our results, we suggest C(6) as the most promising position of the flavonoid scaffold to introduce chemical modifications to improve affinity, selectivity, and inhibition of PLA2-IIA by flavonoids.

Active compounds in Chinese herbs and medicinal animal products which promote blood circulation via inhibition of Na+, K+-ATPase.

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Tzen, Jason Tc; Chen, Ronald Jy; Chung, Tse-Yu; Chen, Yi-Ching; Lin, Nan-Hei

2010-01-01

The therapeutic effect of cardiac glycosides for congestive heart failure lies in their reversible inhibition on Na+, K+-ATPase located in human myocardium. Several steroid-like compounds containing a core structure similar to cardiac glycosides have been found in many Chinese herbs and medicinal animal products conventionally used to promote blood circulation. They are putatively responsible for the therapeutic effect of those medicinal products via the same mechanism of inhibiting Na+, K+-ATPase. Inhibitory potency on Na+, K+-ATPase by ginsenosides, one of the identified steroid-like compounds, is significantly affected by sugar attachment that might cause steric hindrance of their binding to Na+, K+-ATPase. Ginsenosides with sugar moieties attached only to the C-3 position of the steroid-like structure, equivalent to the sugar position in cardiac glycosides, substantially inhibit Na+, K+-ATPase. However, their inhibitory potency is abolished when sugar moieties are linked to the C-6 or C-20 position of the steroid-like structure. In contrast, no appreciable contents of steroid-like compounds are found in danshen, a well-known Chinese herb traditionally regarded as an effective medicine promoting blood circulation. Instead, magnesium lithospermate B (MLB), the major soluble ingredient in danshen, is assumed to be responsible for the therapeutic effect by inhibiting Na+, K+-ATPase in a manner comparable to cardiac glycosides. Neuroprotective effects of cardiac glycosides, ginsenosides and MLB against ischemic stroke were accordingly observed in a cortical brain slice-based assay model. Whether the neuroprotection is also triggered by inhibition of Na+, K+-ATPase remains to be investigated. Molecular modeling suggests that cardiac glycosides, ginsenosides and MLB presumably bind to the same extracellular pocket of the Na+, K+-ATPase alpha subunit.

Statins induce apoptosis in rat and human myotube cultures by inhibiting protein geranylgeranylation but not ubiquinone

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Johnson, Timothy E.; Zhang, Xiaohua; Bleicher, Kimberly B.; Dysart, Gary; Loughlin, Amy F.; Schaefer, William H.; Umbenhauer, Diane R.

2004-01-01

Statins are widely used to treat lipid disorders. These drugs are safe and well tolerated; however, in <1% of patients, myopathy and/or rhabdomyolysis can develop. To better understand the mechanism of statin-induced myopathy, we examined the ability of structurally distinct statins to induce apoptosis in an optimized rat myotube model. Compound A (a lactone) and Cerivastatin (an open acid) induced apoptosis, as measured by TUNEL and active caspase 3 staining, in a concentration- and time-dependent manner. In contrast, an epimer of Compound A (Compound B) exhibited a much weaker apoptotic response. Statin-induced apoptosis was completely prevented by mevalonate or geranylgeraniol, but not by farnesol. Zaragozic acid A, a squalene synthase inhibitor, caused no apoptosis on its own and had no effect on Compound-A-induced myotoxicity, suggesting the apoptosis was not a result of cholesterol synthesis inhibition. The geranylgeranyl transferase inhibitors GGTI-2133 and GGTI-2147 caused apoptosis in myotubes; the farnesyl transferase inhibitor FTI-277 exhibited a much weaker effect. In addition, the prenylation of rap1a, a geranylgeranylated protein, was inhibited by Compound A in myotubes at concentrations that induced apoptosis. A similar statin-induced apoptosis profile was seen in human myotube cultures but primary rat hepatocytes were about 200-fold more resistant to statin-induced apoptosis. Although the statin-induced hepatotoxicity could be attenuated with mevalonate, no effect was found with either geranylgeraniol or farnesol. In studies assessing ubiquinone levels after statin treatment in rat and human myotubes, there was no correlation between ubiquinone levels and apoptosis. Taken together, these observations suggest that statins cause apoptosis in myotube cultures in part by inhibiting the geranylgeranylation of proteins, but not by suppressing ubiquinone concentration. Furthermore, the data from primary hepatocytes suggests a cell-type differential

Multivalent dendrimeric compounds containing carbohydrates expressed on immune cells inhibit infection by primary isolates of HIV-1

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Rosa Borges, Andrew; Wieczorek, Lindsay; Johnson, Benitra; Benesi, Alan J.; Brown, Bruce K.; Kensinger, Richard D.; Krebs, Fred C.; Wigdahl, Brian; Blumenthal, Robert; Puri, Anu; McCutchan, Francine E.; Birx, Deborah L.; Polonis, Victoria R.; Schengrund, Cara-Lynne

2010-01-01

Specific glycosphingolipids (GSL), found on the surface of target immune cells, are recognized as alternate cell surface receptors by the human immunodeficiency virus type 1 (HIV-1) external envelope glycoprotein. In this study, the globotriose and 3'-sialyllactose carbohydrate head groups found on two GSL were covalently attached to a dendrimer core to produce two types of unique multivalent carbohydrates (MVC). These MVC inhibited HIV-1 infection of T cell lines and primary peripheral blood mononuclear cells (PBMC) by T cell line-adapted viruses or primary isolates, with IC 50 s ranging from 0.1 to 7.4 μg/ml. Inhibition of Env-mediated membrane fusion by MVC was also observed using a dye-transfer assay. These carbohydrate compounds warrant further investigation as a potential new class of HIV-1 entry inhibitors. The data presented also shed light on the role of carbohydrate moieties in HIV-1 virus-host cell interactions. -- Research Highlights: →Multivalent carbohydrates (MVCs) inhibited infection of PBMCs by HIV-1. →MVCs inhibited infection by T cell line-adapted viruses. →MVCs inhibited infection by primary isolates of HIV-1. →MVCs inhibited Env-mediated membrane fusion.

Potent inhibitors of human LAT1 (SLC7A5) transporter based on dithiazole and dithiazine compounds for development of anticancer drugs.

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Napolitano, Lara; Scalise, Mariafrancesca; Koyioni, Maria; Koutentis, Panayiotis; Catto, Marco; Eberini, Ivano; Parravicini, Chiara; Palazzolo, Luca; Pisani, Leonardo; Galluccio, Michele; Console, Lara; Carotti, Angelo; Indiveri, Cesare

2017-11-01

The LAT1 transporter is acknowledged as a pharmacological target of tumours since it is strongly overexpressed in many human cancers. The purpose of this work was to find novel compounds exhibiting potent and prolonged inhibition of the transporter. To this aim, compounds based on dithiazole and dithiazine scaffold have been screened in the proteoliposome experimental model. Inhibition was tested on the antiport catalysed by hLAT1 as transport of extraliposomal [ 3 H]histidine in exchange with intraliposomal histidine. Out of 59 compounds tested, 8 compounds, showing an inhibition higher than 90% at 100µM concentration, were subjected to dose-response analysis. Two of them exhibited IC 50 lower than 1µM. Inhibition kinetics, performed on the two best inhibitors, indicated a mixed type of inhibition with respect to the substrate. Furthermore, inhibition of the transporter was still present after removal of the compounds from the reaction mixture, but was reversed on addition of dithioerythritol, a S-S reducing agent, indicating the formation of disulfide(s) between the compounds and the protein. Molecular docking of the two best inhibitors on the hLAT1 homology structural model, highlighted interaction with the substrate binding site and formation of a covalent bond with the residue C407. Indeed, the inhibition was impaired in the hLAT1 mutant C407A confirming the involvement of that Cys residue. Treatment of SiHa cells expressing hLAT1 at relatively high level, with the two most potent inhibitors led to cell death which was not observed after treatment with a compound exhibiting very poor inhibitory effect. Copyright © 2017 Elsevier Inc. All rights reserved.

Structurally modified curcumin analogs inhibit STAT3 phosphorylation and promote apoptosis of human renal cell carcinoma and melanoma cell lines.

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Matthew A Bill

Full Text Available The Janus kinase-2 (Jak2-signal transducer and activator of transcription-3 (STAT3 pathway is critical for promoting an oncogenic and metastatic phenotype in several types of cancer including renal cell carcinoma (RCC and melanoma. This study describes two small molecule inhibitors of the Jak2-STAT3 pathway, FLLL32 and its more soluble analog, FLLL62. These compounds are structurally distinct curcumin analogs that bind selectively to the SH2 domain of STAT3 to inhibit its phosphorylation and dimerization. We hypothesized that FLLL32 and FLLL62 would induce apoptosis in RCC and melanoma cells and display specificity for the Jak2-STAT3 pathway. FLLL32 and FLLL62 could inhibit STAT3 dimerization in vitro. These compounds reduced basal STAT3 phosphorylation (pSTAT3, and induced apoptosis in four separate human RCC cell lines and in human melanoma cell lines as determined by Annexin V/PI staining. Apoptosis was also confirmed by immunoblot analysis of caspase-3 processing and PARP cleavage. Pre-treatment of RCC and melanoma cell lines with FLLL32/62 did not inhibit IFN-γ-induced pSTAT1. In contrast to FLLL32, curcumin and FLLL62 reduced downstream STAT1-mediated gene expression of IRF1 as determined by Real Time PCR. FLLL32 and FLLL62 significantly reduced secretion of VEGF from RCC cell lines in a dose-dependent manner as determined by ELISA. Finally, each of these compounds inhibited in vitro generation of myeloid-derived suppressor cells. These data support further investigation of FLLL32 and FLLL62 as lead compounds for STAT3 inhibition in RCC and melanoma.

Biofilm inhibition activity of compounds isolated from two Eunicea species collected at the Caribbean Sea

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Yenny Martínez Díaz

Full Text Available Abstract Biofilm has a primary role in the pathogenesis of diseases and in the attachment of multicellular organisms to a fouled surface. Because of that, the control of bacterial biofilms has been identified as an important target. In the present study, five lipid compounds isolated from soft coral Eunicea sp. and three terpenoids together with a mixture of sterols from Eunicea fusca collected at the Colombian Caribbean Sea showed different effectiveness against biofilm formation by three marine bacteria associated with immersed fouled surfaces, Ochrobactrum pseudogringnonense,Alteromona macleodii and Vibrio harveyi, and against two known biofilm forming bacteria, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923. The pure compounds were characterized by NMR, HRESI-MS, HRGC-MS and optical rotation. The most effective compounds were batyl alcohol (1 and fuscoside E peracetate (6, acting against four strains without affecting their microbial growth. Compound 1 showed biofilm inhibition greater than 30% against A. macleodii, and up to 60% against O. pseudogringnonense,V. harveyi and S. aureus. Compound 6 inhibited O. pseudogringnonense and V. harveyi between 25 and 50%, and P. aeruginosa or S. aureus up to 60% at 0.5 mg/ml. The results suggest that these compounds exhibit specific biofilm inhibition with lower antimicrobial effect against the bacterial species assayed.

Gemfibrozil, a Lipid-lowering Drug, Inhibits the Induction of Nitric-oxide Synthase in Human Astrocytes*

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Pahan, Kalipada; Jana, Malabendu; Liu, Xiaojuan; Taylor, Bradley S.; Wood, Charles; Fischer, Susan M.

2007-01-01

Gemfibrozil, a lipid-lowering drug, inhibited cytokine-induced production of NO and the expression of inducible nitric-oxide synthase (iNOS) in human U373MG astroglial cells and primary astrocytes. Similar to gemfibrozil, clofibrate, another fibrate drug, also inhibited the expression of iNOS. Inhibition of human iNOS promoter-driven luciferase activity by gemfibrozil in cytokine-stimulated U373MG astroglial cells suggests that this compound inhibits the transcription of iNOS. Since gemfibrozil is known to activate peroxisome proliferator-activated receptor-α (PPAR-α), we investigated the role of PPAR-α in gemfibrozil-mediated inhibition of iNOS. Gemfibrozil induced peroxisome proliferator-responsive element (PPRE)-dependent luciferase activity, which was inhibited by the expression of ΔhPPAR-α, the dominant-negative mutant of human PPAR-α. However, ΔhPPAR-α was unable to abrogate gemfibrozil-mediated inhibition of iNOS suggesting that gemfibrozil inhibits iNOS independent of PPAR-α. The human iNOS promoter contains consensus sequences for the binding of transcription factors, including interferon-γ (IFN-γ) regulatory factor-1 (IRF-1) binding to interferon-stimulated responsive element (ISRE), signal transducer and activator of transcription (STAT) binding to γ-activation site (GAS), nuclear factor-κB (NF-κB), activator protein-1 (AP-1), and CCAAT/enhancer-binding protein β (C/EBPβ); therefore, we investigated the effect of gemfibrozil on the activation of these transcription factors. The combination of interleukin (IL)-1β and IFN-γ induced the activation of NF-κB, AP-1, C/EBPβ, and GAS but not that of ISRE, suggesting that IRF-1 may not be involved in cytokine-induced expression of iNOS in human astrocytes. Interestingly, gemfibrozil strongly inhibited the activation of NF-κB, AP-1, and C/EBPβ but not that of GAS in cytokine-stimulated astroglial cells. These results suggest that gemfibrozil inhibits the induction of iNOS probably by

Tyrosinase Inhibition Type of Isolated Compounds Obtained from Pachyrhizus erosus

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Endang Lukitaningsih

2013-12-01

Full Text Available In Indonesia, Bengkoang (Phacyrhizus erosus have been used as one of cosmetics especially as sun screening and skin whitening materials. Six active compounds in Bengkoang with antioxidant and skin whitening activities have been isolated, namely daidzein, daidzin, genistin, (8,9-furanyl-pterocarpan-3-ol, 4-(2-(furane-2-ylethyl-2-methyl-2,5-dihydro-furane-3-carbaldehyde and 2-butoxy-2,5-bis(hydroxymethyl-tetrahydrofurane-3,4-diol. According to literatures, the type of their tyrosinase inhibitory activity has not yet reported. The determination of whitening activity of each compound was evaluated by the evaluation of Lineweaver-Burk plot. The result showed that five compounds had competitive inhibitory activity and 8,9-furanyl-pterocarpan-3-ol showed a non-competitive inhibition.

Inhibition by Commercial Aminoglycosides of Human Connexin Hemichannels Expressed in Bacteria

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Mariana C. Fiori

2017-11-01

Full Text Available In addition to gap junctional channels that mediate cell-to-cell communication, connexins form hemichannels that are present at the plasma membrane. Since hemichannels are permeable to small hydrophilic compounds, including metabolites and signaling molecules, their abnormal opening can cause or contribute to cell damage in disorders such as cardiac infarct, stroke, deafness, skin diseases, and cataracts. Therefore, hemichannels are potential pharmacological targets. A few aminoglycosides, well-known broad-spectrum antibiotics, have been shown to inhibit hemichannels. Here, we tested several commercially available aminoglycosides for inhibition of human connexin hemichannels using a cell-based bacterial growth complementation assay that we developed recently. We found that kanamycin A, kanamycin B, geneticin, neomycin, and paromomycin are effective inhibitors of hemichannels formed by connexins 26, 43, and 46 (Cx26, Cx43, and Cx46. Because of the >70 years of clinical experience with aminoglycosides and the fact that several of the aminoglycosides tested here have been used in humans, they are promising starting points for the development of effective connexin hemichannel inhibitors.

Analysis of Indonesian Spice Essential Oil Compounds That Inhibit Locomotor Activity in Mice

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Muchtaridi; Diantini, Adjeng; Subarnas, Anas

2011-01-01

Some fragrance components of spices used for cooking are known to have an effect on human behavior. The aim of this investigation was to examine the effect of the essential oils of basil (Ocimum formacitratum L.) leaves, lemongrass (Cymbopogon citrates L.) herbs, ki lemo (Litsea cubeba L.) bark, and laja gowah (Alpinia malaccencis Roxb.) rhizomes on locomotor activity in mice and identify the active component(s) that might be responsible for the activity. The effect of the essential oils was studied by a wheel cage method and the active compounds of the essential oils were identified by GC/MS analysis. The essential oils were administered by inhalation at doses of 0.1, 0.3, and 0.5 mL/cage. The results showed that the four essential oils had inhibitory effects on locomotor activity in mice. Inhalation of the essential oils of basil leaves, lemongrass herbs, ki lemo bark, and laja gowah rhizomes showed the highest inhibitory activity at doses of 0.5 (57.64%), 0.1 (55.72%), 0.5 (60.75%), and 0.1 mL/cage (47.09%), respectively. The major volatile compounds 1,8-cineole, α-terpineol, 4-terpineol, citronelol, citronelal, and methyl cinnamate were identified in blood plasma of mice after inhalation of the four oils. These compounds had a significant inhibitory effect on locomotion after inhalation. The volatile compounds of essential oils identified in the blood plasma may correlate with the locomotor-inhibiting properties of the oil when administered by inhalation.

Theophylline prevents NAD+ depletion via PARP-1 inhibition in human pulmonary epithelial cells

International Nuclear Information System (INIS)

Moonen, Harald J.J.; Geraets, Liesbeth; Vaarhorst, Anika; Bast, Aalt; Wouters, Emiel F.M.; Hageman, Geja J.

2005-01-01

Oxidative DNA damage, as occurs during exacerbations in chronic obstructive pulmonary disease (COPD), highly activates the nuclear enzyme poly(ADP-ribose)polymerase-1 (PARP-1). This can lead to cellular depletion of its substrate NAD + , resulting in an energy crisis and ultimately in cell death. Inhibition of PARP-1 results in preservation of the intracellular NAD + pool, and of NAD + -dependent cellular processes. In this study, PARP-1 activation by hydrogen peroxide decreased intracellular NAD + levels in human pulmonary epithelial cells, which was found to be prevented in a dose-dependent manner by theophylline, a widely used compound in the treatment of COPD. This enzyme inhibition by theophylline was confirmed in an ELISA using purified human PARP-1 and was found to be competitive by nature. These findings provide new mechanistic insights into the therapeutic effect of theophylline in oxidative stress-induced lung pathologies

Inhibition of Enzymatic Browning of Chlorogenic Acid by Sulfur-Containing Compounds

NARCIS (Netherlands)

Kuijpers, T.F.M.; Narvaez Cuenca, C.E.; Vincken, J.P.; Verloop, J.W.; Berkel, van W.J.H.; Gruppen, H.

2012-01-01

The antibrowning activity of sodium hydrogen sulfite (NaHSO3) was compared to that of other sulfur-containing compounds. Inhibition of enzymatic browning was investigated using a model browning system consisting of mushroom tyrosinase and chlorogenic acid (5-CQA). Development of brown color

Conifer flavonoid compounds inhibit detoxification enzymes and synergize insecticides.

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Wang, Zhiling; Zhao, Zhong; Cheng, Xiaofei; Liu, Suqi; Wei, Qin; Scott, Ian M

2016-02-01

Detoxification by glutathione S-transferases (GSTs) and esterases are important mechanisms associated with insecticide resistance. Discovery of novel GST and esterase inhibitors from phytochemicals could provide potential new insecticide synergists. Conifer tree species contain flavonoids, such as taxifolin, that inhibit in vitro GST activity. The objectives were to test the relative effectiveness of taxifolin as an enzyme inhibitor and as an insecticide synergist in combination with the organophosphorous insecticide, Guthion (50% azinphos-methyl), and the botanical insecticide, pyrethrum, using an insecticide-resistant Colorado potato beetle (CPB) Leptinotarsa decemlineata (Say) strain. Both taxifolin and its isomer, quercetin, increased the mortality of 1(st) instar CPB larvae after 48h when combined with Guthion, but not pyrethrum. Taxifolin had greater in vitro esterase inhibition compared with the commonly used esterase inhibitor, S, S, S-tributyl phosphorotrithioate (DEF). An in vivo esterase and GST inhibition effect after ingestion of taxifolin was measured, however DEF caused a greater suppression of esterase activity. This study demonstrated that flavonoid compounds have both in vitro and in vivo esterase inhibition, which is likely responsible for the insecticide synergism observed in insecticide-resistant CPB. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Review of the inhibition of biological activities of food-related selected toxins by natural compounds.

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Friedman, Mendel; Rasooly, Reuven

2013-04-23

There is a need to develop food-compatible conditions to alter the structures of fungal, bacterial, and plant toxins, thus transforming toxins to nontoxic molecules. The term 'chemical genetics' has been used to describe this approach. This overview attempts to survey and consolidate the widely scattered literature on the inhibition by natural compounds and plant extracts of the biological (toxicological) activity of the following food-related toxins: aflatoxin B1, fumonisins, and ochratoxin A produced by fungi; cholera toxin produced by Vibrio cholerae bacteria; Shiga toxins produced by E. coli bacteria; staphylococcal enterotoxins produced by Staphylococcus aureus bacteria; ricin produced by seeds of the castor plant Ricinus communis; and the glycoalkaloid α-chaconine synthesized in potato tubers and leaves. The reduction of biological activity has been achieved by one or more of the following approaches: inhibition of the release of the toxin into the environment, especially food; an alteration of the structural integrity of the toxin molecules; changes in the optimum microenvironment, especially pH, for toxin activity; and protection against adverse effects of the toxins in cells, animals, and humans (chemoprevention). The results show that food-compatible and safe compounds with anti-toxin properties can be used to reduce the toxic potential of these toxins. Practical applications and research needs are suggested that may further facilitate reducing the toxic burden of the diet. Researchers are challenged to (a) apply the available methods without adversely affecting the nutritional quality, safety, and sensory attributes of animal feed and human food and (b) educate food producers and processors and the public about available approaches to mitigating the undesirable effects of natural toxins that may present in the diet.

Flavonoids purified from parsley inhibit human blood platelet aggregation and adhesion to collagen under flow.

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Gadi, Dounia; Bnouham, Mohamed; Aziz, Mohammed; Ziyyat, Abderrahim; Legssyer, Abdelkhaleq; Bruel, Arlette; Berrabah, Mohamed; Legrand, Chantal; Fauvel-Lafeve, Françoise; Mekhfi, Hassane

2012-08-10

Blood platelets are directly involved in both haemostatic and pathologic thrombotic processes, through their adhesion, secretion and aggregation. In this study, we investigated the effect of genins (aglycone flavonoids without sugar group) isolated from parsley (Petroselinum crispum) leaves in vitro on human platelet aggregation and adhesion to a collagen-coated surface under physiologic flow conditions. The aggregation and adhesion studies were monitored after pre-incubation of platelets with genins. Genins inhibited dose dependently aggregation induced by thrombin, ADP and collagen. The strongest effect was observed in collagen induced aggregation (IC50 = 0.08 ± 0.01 mg/ml). The HPLC identification of genins compounds revealed the presence of keampferol, apigenin and other not identified compounds. The aggregation tests showed that these compounds have anti-aggregating activity. In addition, adhesion of human platelets to collagen was greatly decreased (over 75 %) by genins (0.3 mg/ml). While the mechanism by which genins act is unclear, we suggest that these compounds may interfere with a multiple target step in the haemostasis process. These results show that genins isolated from parsley has a potent antiplatelet activity. It may be an important source of beneficial antiplatelet compounds that decrease thrombosis and cardiovascular diseases.

Human erythrocytes inhibit complement-mediated solubilization of immune complexes by human serum

International Nuclear Information System (INIS)

Dorval, B.L.

1987-01-01

The aim of this study was to develop an autologus human system to evaluate the effects of human erythrocytes on solubilization of immune complex precipitates (IC) by human serum. Incubation of IC with fresh human serum or guinea pig serum resulted in solubilization of IC. When packed erythrocytes were added to human serum or guinea pig serum binding of IC to the erythrocyte occurred and IC solubilization was inhibited significantly (p <.025). Sheep erythrocytes did not bind IC or inhibit IC solubilization. To evaluate the role of human erythrocyte complement receptor (CR1) on these findings, human erythrocytes were treated with trypsin or anti-CR1 antibodies. Both treatments abrogated IC binding to human erythrocytes but did not affect the ability of the human erythrocyte to inhibit IC solubilization. Radioimmunoassay was used to measure C3, C4 and C5 activation in human serum after incubation with IC, human erythrocytes, human erythrocytes plus IC, whole blood or in whole blood plus IC

The effects of compound danshen dripping pills and human umbilical cord blood mononuclear cell transplant after acute myocardial infarction.

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Jun, Yi; Chunju, Yuan; Qi, Ai; Liuxia, Deng; Guolong, Yu

2014-04-01

The low frequency of survival of stem cells implanted in the myocardium after acute myocardial infarction may be caused by inflammation and oxidative stress in the myocardial microenvironment. We evaluated the effects of a traditional Chinese medicine, Compound Danshen Dripping Pills, on the cardiac microenvironment and cardiac function when used alone or in combination with human umbilical cord blood mononuclear cell transplant after acute myocardial infarction. After surgically induced acute myocardial infarction, rabbits were treated with Compound Danshen Dripping Pills alone or in combination with human umbilical cord blood mononuclear cell transplant. Evaluation included histology, measurement of left ventricular ejection fraction and fractional shortening, leukocyte count, count of green fluorescent protein positive cells, superoxide dismutase activity, and malondialdehyde content. Combination treatment with Compound Danshen Dripping Pills and human umbilical cord blood mononuclear cell transplant significantly increased the survival of implanted cells, inhibited cardiac cell apoptosis, decreased oxidative stress, decreased the inflammatory response, and improved cardiac function. Rabbits treated with either Compound Danshen Dripping Pills or human umbilical cord blood mononuclear cells alone had improvement in these effects compared with untreated control rabbits. Combination therapy with Compound Danshen Dripping Pills and human umbilical cord blood mononuclear cells may improve cardiac function and morphology after acute myocardial infarction.

An antifungal compound produced by Bacillus subtilis YM 10-20 inhibits germination of Penicillium roqueforti conidiospores

NARCIS (Netherlands)

Chitarra, G.S.; Breeuwer, P.; Nout, M.J.R.; Aelst, van A.C.; Rombouts, F.M.; Abee, T.

2003-01-01

Aims: To identify and characterize an antifungal compound produced by Bacillus subtilis YM 10-20 which prevents spore germination of Penicillium roqueforti . Methods and Results: The antifungal compound was isolated by acid precipitation with HCl. This compound inhibited fungal germination and

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.

Imidazopyridine Compounds Inhibit Mycobacterial Growth by Depleting ATP Levels.

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O'Malley, Theresa; Alling, Torey; Early, Julie V; Wescott, Heather A; Kumar, Anuradha; Moraski, Garrett C; Miller, Marvin J; Masquelin, Thierry; Hipskind, Philip A; Parish, Tanya

2018-06-01

The imidazopyridines are a promising new class of antitubercular agents with potent activity in vitro and in vivo We isolated mutants of Mycobacterium tuberculosis resistant to a representative imidazopyridine; the mutants had large shifts (>20-fold) in MIC. Whole-genome sequencing revealed mutations in Rv1339, a hypothetical protein of unknown function. We isolated mutants resistant to three further compounds from the series; resistant mutants isolated from two of the compounds had single nucleotide polymorphisms in Rv1339 and resistant mutants isolated from the third compound had single nucleotide polymorphisms in QcrB, the proposed target for the series. All the strains were resistant to two compounds, regardless of the mutation, and a strain carrying the QcrB T313I mutation was resistant to all of the imidazopyridine derivatives tested, confirming cross-resistance. By monitoring pH homeostasis and ATP generation, we confirmed that compounds from the series were targeting QcrB; imidazopyridines disrupted pH homeostasis and depleted ATP, providing further evidence of an effect on the electron transport chain. A representative compound was bacteriostatic against replicating bacteria, consistent with a mode of action against QcrB. The series had a narrow inhibitory spectrum, with no activity against other bacterial species. No synergy or antagonism was seen with other antituberculosis drugs under development. In conclusion, our data support the hypothesis that the imidazopyridine series functions by reducing ATP generation via inhibition of QcrB. Copyright © 2018 O'Malley et al.

Inhibition effect of fatty amides with secondary compound on carbon steel corrosion in hydrodynamic condition

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Ibrahim, I. M.; Jai, J.; Daud, M.; Hashim, Md A.

2018-03-01

The inhibition effect demonstrates an increase in the inhibition performance in presence of a secondary compound in the inhibited solution. This study introduces fatty amides as corrosion inhibitor and oxygen scavenger, namely, sodium sulphite as a secondary compound. The main objective is to determine the synergistic inhibition effect of a system by using fatty amides together with sodium sulphite in hydrodynamic condition. The synergistic inhibition of fatty amides and sodium sulphite on corrosion of carbon steel in 3.5 wt% sodium chloride solution had been studied using linear polarization resistance method and scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX). Electrochemical measurement was carried out using rotating cylinder electrode at different flow regimes (static, laminar, transition and turbulent). Linear polarization resistance experiments showed the changes in polarization resistance when the rotation speed increased. It found that, by addition of fatty amides together with sodium sulphite in test solution, the inhibition efficiency increased when rotation speed increased. The results collected from LPR experiment correlated with results from SEM-EDX. The results showed inhibition efficiency of system was enhanced when fatty amides and oxygen scavengers were present together.

Rapid, convenient method for screening imidazole-containing compounds for heme oxygenase inhibition.

Science.gov (United States)

Vlahakis, Jason Z; Rahman, Mona N; Roman, Gheorghe; Jia, Zongchao; Nakatsu, Kanji; Szarek, Walter A

2011-01-01

Sensitive assays for measuring heme oxygenase activity have been based on the gas-chromatographic detection of carbon monoxide using elaborate, expensive equipment. The present study describes a rapid and convenient method for screening imidazole-containing candidates for inhibitory activity against heme oxygenase using a plate reader, based on the spectroscopic evaluation of heme degradation. A PowerWave XS plate reader was used to monitor the absorbance (as a function of time) of heme bound to purified truncated human heme oxygenase-1 (hHO-1) in the individual wells of a standard 96-well plate (with or without the addition of a test compound). The degradation of heme by heme oxygenase-1 was initiated using l-ascorbic acid, and the collected relevant absorbance data were analyzed by three different methods to calculate the percent control activity occurring in wells containing test compounds relative to that occurring in control wells with no test compound present. In the cases of wells containing inhibitory compounds, significant shifts in λ(max) from 404 to near 412 nm were observed as well as a decrease in the rate of heme degradation relative to that of the control. Each of the three methods of data processing (overall percent drop in absorbance over 1.5h, initial rate of reaction determined over the first 5 min, and estimated pseudo first-order reaction rate constant determined over 1.5h) gave similar and reproducible results for percent control activity. The fastest and easiest method of data analysis was determined to be that using initial rates, involving data acquisition for only 5 min once reactions have been initiated using l-ascorbic acid. The results of the study demonstrate that this simple assay based on the spectroscopic detection of heme represents a rapid, convenient method to determine the relative inhibitory activity of candidate compounds, and is useful in quickly screening a series or library of compounds for heme oxygenase inhibition

Analysis of Indonesian Spice Essential Oil Compounds That Inhibit Locomotor Activity in Mice

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Anas Subarnas

2011-04-01

Full Text Available Some fragrance components of spices used for cooking are known to have an effect on human behavior. The aim of this investigation was to examine the effect of the essential oils of basil (Ocimum formacitratum L. leaves, lemongrass (Cymbopogon citrates L. herbs, ki lemo (Litsea cubeba L. bark, and laja gowah (Alpinia malaccencis Roxb. rhizomes on locomotor activity in mice and identify the active component(s that might be responsible for the activity. The effect of the essential oils was studied by a wheel cage method and the active compounds of the essential oils were identified by GC/MS analysis. The essential oils were administered by inhalation at doses of 0.1, 0.3, and 0.5 mL/cage. The results showed that the four essential oils had inhibitory effects on locomotor activity in mice. Inhalation of the essential oils of basil leaves, lemongrass herbs, ki lemo bark, and laja gowah rhizomes showed the highest inhibitory activity at doses of 0.5 (57.64%, 0.1 (55.72%, 0.5 (60.75%, and 0.1 mL/cage (47.09%, respectively. The major volatile compounds 1,8-cineole, α-terpineol, 4-terpineol, citronelol, citronelal, and methyl cinnamate were identified in blood plasma of mice after inhalation of the four oils. These compounds had a significant inhibitory effect on locomotion after inhalation. The volatile compounds of essential oils identified in the blood plasma may correlate with the locomotor-inhibiting properties of the oil when administered by inhalation.

Compound K, a Ginsenoside Metabolite, Inhibits Colon Cancer Growth via Multiple Pathways Including p53-p21 Interactions

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Eugene B. Chang

2013-01-01

Full Text Available Compound K (20-O-beta-D-glucopyranosyl-20(S-protopanaxadiol, CK, an intestinal bacterial metabolite of ginseng protopanaxadiol saponins, has been shown to inhibit cell growth in a variety of cancers. However, the mechanisms are not completely understood, especially in colorectal cancer (CRC. A xenograft tumor model was used first to examine the anti-CRC effect of CK in vivo. Then, multiple in vitro assays were applied to investigate the anticancer effects of CK including antiproliferation, apoptosis and cell cycle distribution. In addition, a qPCR array and western blot analysis were executed to screen and validate the molecules and pathways involved. We observed that CK significantly inhibited the growth of HCT-116 tumors in an athymic nude mouse xenograft model. CK significantly inhibited the proliferation of human CRC cell lines HCT-116, SW-480, and HT-29 in a dose- and time-dependent manner. We also observed that CK induced cell apoptosis and arrested the cell cycle in the G1 phase in HCT-116 cells. The processes were related to the upregulation of p53/p21, FoxO3a-p27/p15 and Smad3, and downregulation of cdc25A, CDK4/6 and cyclin D1/3. The major regulated targets of CK were cyclin dependent inhibitors, including p21, p27, and p15. These results indicate that CK inhibits transcriptional activation of multiple tumor-promoting pathways in CRC, suggesting that CK could be an active compound in the prevention or treatment of CRC.

Inhibition of dehydrogenase activity in petroleum refinery wastewater bacteria by phenolic compounds

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Gideon C. Okpokwasili

2010-04-01

Full Text Available The toxicity of phenol, 2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, 2-chlorophenol, 4-chlorophenol, 4-bromophenol and 3,5-dimethylphenol on Pseudomonas, Bacillus and Escherichia species isolated from petroleum refinery wastewater was assessed via inhibition of dehydrogenase enzyme activity. At low concentrations, 2-nitrophenol, 2-chlorophenol, 4-chlorophenol, 4-bromophenol and 3,5-dimethylphenol stimulated dehydrogenase activity and at sufficient concentrations, phenolic compounds inhibited dehydrogenase activities. Generally, phenol is less toxic than substituted phenols. Estimations of the degree of inhibition/stimulation of dehydrogenase activities showed significant dose-dependent responses that are describable by logistic functions. The toxicity thresholds varied significantly (P < 0.05 among the bacterial strains and phenolic compounds. The median inhibitory concentrations (IC50s ranged from 4.118 ± 0.097 mg.L-1 for 4-nitrophenol against Pseudomonas sp. DAF1 to 1407.997 ± 7.091 mg.L-1 for phenol against Bacillus sp. DISK1. This study suggested that the organisms have moderate sensitivity to phenols and have the potential to be used as indicators for assessment of chemical toxicity. They could also be used as catalysts for degradation of phenols in effluents.

Organic compounds as corrosion inhibitors for mild steel in acidic media: correlation between inhibition efficiency and chemical structure

Energy Technology Data Exchange (ETDEWEB)

Elias, Elizandra C.S.; Chrisman, Erika C.A.N. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica

2009-12-19

The use of inhibitors for mild steels corrosion control which are in contact with aggressive environment is an accepted practice in acid treatment of oil-wells. Organic compounds have been studied to evaluate their corrosion inhibition potential. Film-forming corrosion inhibitors, commonly used to protect oil-field equipment, can be absorbed on the steel surface to give structurally ordered layers. Therefore, the electrons should act as an important role for this adsorption. Studies reveal that organic compounds show significant inhibition efficiency. For this purpose, their molecules should contain N, O and S heteroatoms in various functional groups, long hydrocarbon linear or branched radical and anion and cation active components. However, most of these compounds are not only expensive but also toxic to living beings. According to the 'Green Chemistry' rules, corrosion inhibitors based on organic compounds should be cheap, with low toxicity and have high inhibition efficiency. In this study, the effects of some organic compounds with different groups such as amide, ether, phenyldiamine, anime and aminophenol on the corrosion behavior of mild steel in acidic media have been investigated. The experimental data were obtained by gravimetric measurements. The results show that these compounds reveal a promising corrosion inhibition where phenyldiamine is the most efficient. The effect of molecular structure on the corrosion inhibition efficiency was investigated by semi-empirical quantum chemical calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, and LUMO-HOMO energy gap orbital density were calculated. The relations between the inhibition efficiency and some quantum parameters are discussed and correlations are proposed. The highest values for the HOMO densities were found in the vicinity nitrogen atom, indicating that it is the most probable adsorption center

Characterization of Compounds with Tumor-Cell Proliferation Inhibition Activity from Mushroom (Phellinus baumii) Mycelia Produced by Solid-State Fermentation.

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Zhang, Henan; Shao, Qian; Wang, Wenhan; Zhang, Jingsong; Zhang, Zhong; Liu, Yanfang; Yang, Yan

2017-04-27

The inhibition of tumor-cell proliferationbyan organicsolvent extract from the solid-state fermentation of Phellinus baumii mycelia inoculated in rice medium was investigated in vitro. The active compounds inhibiting tumor-cell proliferation were characterized. Results revealed that all (petroleum ether, chloroform, ethyl acetate, and butanol) fractions inhibited tumor-cell proliferation in a dose-dependent fashion. The ethyl acetate extract had the highest inhibitory effecton tumor-cell proliferation, and the butanol fraction had the lowest. Six compounds were isolated and purified from the ethyl acetate extract of P. baumii mycelia by the tandem application of silica-gel column chromatography (SGCC), high-speed countercurrent chromatography (HSCCC), and preparative HPLC. These compounds were identified by NMR and electrospray ionization-mass spectrometry (ESI-MS) spectroscopic methods as ergosterol (RF1), ergosta-7,22-dien-3β-yl pentadecanoate (RF3), 3,4-dihydroxy benzaldehyde(RF6), inoscavinA (RF7), baicalein(RF10), and 24-ethylcholesta-5,22-dien-3β-ol (RF13). To further clarify the activity of these compounds, the cell-proliferation-inhibition tests of these compounds on various tumor cells were carried out and evaluatedin vitro. Results suggested that compounds RF6, RF7, and RF10 had potent inhibition effects on the proliferation of a series of tumor cell lines, including K562, L1210, SW620, HepG2, LNCaP, and MCF-7cells. These findings indicated that P. baumii mycelia produced by solid-state fermentation in rice canbe used to obtain active compounds with the ability to inhibittumor-cell proliferation.

Characterization of Compounds with Tumor–Cell Proliferation Inhibition Activity from Mushroom (Phellinus baumii Mycelia Produced by Solid-State Fermentation

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Henan Zhang

2017-04-01

Full Text Available The inhibition of tumor-cell proliferationbyan organicsolvent extract from the solid-state fermentation of Phellinus baumii mycelia inoculated in rice medium was investigated in vitro. The active compounds inhibiting tumor-cell proliferation were characterized. Results revealed that all (petroleum ether, chloroform, ethyl acetate, and butanol fractions inhibited tumor-cell proliferation in a dose-dependent fashion. The ethyl acetate extract had the highest inhibitory effecton tumor-cell proliferation, and the butanol fraction had the lowest. Six compounds were isolated and purified from the ethyl acetate extract of P. baumii mycelia by the tandem application of silica-gel column chromatography (SGCC, high-speed countercurrent chromatography (HSCCC, and preparative HPLC. These compounds were identified by NMR and electrospray ionization-mass spectrometry (ESI-MS spectroscopic methods as ergosterol (RF1, ergosta-7,22-dien-3β-yl pentadecanoate (RF3, 3,4-dihydroxy benzaldehyde(RF6, inoscavinA (RF7, baicalein(RF10, and 24-ethylcholesta-5,22-dien-3β-ol (RF13. To further clarify the activity of these compounds, the cell-proliferation-inhibition tests of these compounds on various tumor cells were carried out and evaluatedin vitro. Results suggested that compounds RF6, RF7, and RF10 had potent inhibition effects on the proliferation of a series of tumor cell lines, including K562, L1210, SW620, HepG2, LNCaP, and MCF-7cells. These findings indicated that P. baumii mycelia produced by solid-state fermentation in rice canbe used to obtain active compounds with the ability to inhibittumor-cell proliferation.

Drug Repurposing Screening Identifies Novel Compounds That Effectively Inhibit Toxoplasma gondii Growth

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Dittmar, Ashley J.; Drozda, Allison A.

2016-01-01

ABSTRACT The urgent need to develop new antimicrobial therapies has spawned the development of repurposing screens in which well-studied drugs and other types of compounds are tested for potential off-label uses. As a proof-of-principle screen to identify compounds effective against Toxoplasma gondii, we screened a collection of 1,120 compounds for the ability to significantly reduce Toxoplasma replication. A total of 94 compounds blocked parasite replication with 50% inhibitory concentrations of parasite invasion and replication but did so independently of inhibition of dopamine or other neurotransmitter receptor signaling. Tamoxifen, which is an established inhibitor of the estrogen receptor, also reduced parasite invasion and replication. Even though Toxoplasma can activate the estrogen receptor, tamoxifen inhibits parasite growth independently of this transcription factor. Tamoxifen is also a potent inducer of autophagy, and we find that the drug stimulates recruitment of the autophagy marker light chain 3-green fluorescent protein onto the membrane of the vacuolar compartment in which the parasite resides and replicates. In contrast to other antiparasitic drugs, including pimozide, tamoxifen treatment of infected cells leads to a time-dependent elimination of intracellular parasites. Taken together, these data suggest that tamoxifen restricts Toxoplasma growth by inducing xenophagy or autophagic destruction of this obligate intracellular parasite. IMPORTANCE There is an urgent need to develop new therapies to treat microbial infections, and the repurposing of well-characterized compounds is emerging as one approach to achieving this goal. Using the protozoan parasite Toxoplasma gondii, we screened a library of 1,120 compounds and identified several compounds with significant antiparasitic activities. Among these were pimozide and tamoxifen, which are well-characterized drugs prescribed to treat patients with psychiatric disorders and breast cancer

Inhibition of trypsin by condensed tannins and wine.

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Gonçalves, Rui; Soares, Susana; Mateus, Nuno; de Freitas, Victor

2007-09-05

Phenolic compounds are abundant vegetable secondary metabolites in the human diet. The ability of procyanidin oligomers and wine polyphenols to inhibit trypsin activity was studied using a versatile and reliable in vitro method. The hydrolysis of the chromogenic substrate N-benzoyl-d,l-arginine-p-nitroanilide (BApNA) by trypsin was followed by spectrophotometry in the presence and absence of condensed tannins and wine. A clear relationship between the degree of polymerization of procyanidins and enzymatic inhibition was observed. Trypsin activity inhibition was also detected in several types of wine. In general, the inhibition increased with the concentration of phenolic compounds in wines. These results may be relevant when considering these compounds as antinutritional factors, thereby contributing to a reduced absorption of nutrients.

Inhibition in the Human Auditory Cortex.

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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.

Inhibition of aromatase activity by methyl sulfonyl PCB metabolites in primary culture of human mammary fibroblasts

Energy Technology Data Exchange (ETDEWEB)

Berg, M. van den; Heneweer, M.; Geest, M. de; Sanderson, T. [Inst. for Risk Assessment Sciences and Utrecht Univ. (Netherlands); Jong, P. de [St. Antonius Hospital, Nieuwegein (Netherlands); Bergman, A. [Stockholm Univ., Stockholm (Sweden)

2004-09-15

Methyl sulfonyl PCB metabolites (MeSO2-PCBs) are persistent contaminants and are ubiquitously present in humans and the environment. Lipophilicity of MeSO2- PCB metabolites is similar to the parent compounds and they have been detected in human milk, adipose, liver and lung tissue. 4- MeSO2-PCB-149 is the most abundant PCB metabolite in human adipose tissue and milk at a level of 1.5 ng/g lipids. Human blood concentration of 4-MeSO2-PCB-149 is approximately 0.03 nM. 3- MeSO2-PCB-101 is the predominant PCB metabolite in muscle and blubber in wildlife, such as otter, mink and grey seal. In the environment, they have been linked to chronic and reproductive toxicity in exposed mink. Additionaly, some MeSO{sub 2}-PCBs have been shown to be glucocorticoid receptor (GR) antagonists. Since approximately 60% of all breast tumors are estrogen responsive, exposure to compounds that are able to alter estrogen synthesis through interference with the aromatase enzyme, can lead to changes in estrogen levels and possibly to accelerated or inhibit breast tumor growth. Therefore, it is important to identify exogenous compounds that can alter aromatase activity in addition to those compounds which have direct interaction with the estrogen receptor (ER). Aromatase (CYP19) comprises the ubiquitous flavoprotein, NADPH-cytochrome P450 reductase, and a unique cytochrome P450 that is exclusively expressed in estrogen producing cells. Previous studies have revealed that expression of the aromatase gene is regulated in a species- and tissue specific manner. In healthy breast tissue, the predominantly active aromatase promoter region I.4 is regulated by glucocorticoids and class I cytokines. Therefore, it is important to investigate possible aromatase inhibiting properties of MeSO{sub 2}-PCBs (as anti glucocorticoids?) in relevant human tissues. We used primary human mammary fibroblasts because of their role in breast cancer development. We compared the results in primary fibroblasts with

Photolytic inhibition and labeling of proteins with aryl diazonium compounds

International Nuclear Information System (INIS)

Tometsko, A.M.; Turula, J.; Comstock, J.

1978-01-01

In the course of preparing aryl azide derivatives for use as photoprobes, we have observed significant light sensitivity in the precursor aryl diazonium compounds. The photosensitive properties of this class of compounds are of interest since they will seek out cationic binding sites in biological targets, and can be employed to inhibit complementary targets at acid pH. The relationship between photolytic change in the structure of diazonium compounds and the corresponding change in function of a biological target are presented. Experiments are described in which the dark and light sensitive properties of a model diazonium compound, diazobenzene sulfonate (DBS), were determined. The ultraviolet spectra were used to evaluate the dark stability and light sensitivity og DBS. Chymotrypsin and trypsin served as functioning targets for further evaluation of the photochemical properties. Both enzymes are stable to the probe in the dark at acid pH. A rapid loss of enzyme activity was observed following flash photolysis of DBS-enzyme solutions. Photolytic incorporation of radioactive DBS into chymotrypsin was observed. Aryl diazonium salts can be employed to probe the availability of complementary sites in biological targets at different acid pH values. (Author)

Aliphatic acetogenin constituents of avocado fruits inhibit human oral cancer cell proliferation by targeting the EGFR/RAS/RAF/MEK/ERK1/2 pathway

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D’Ambrosio, Steven M.; Han, Chunhua; Pan, Li; Kinghorn, A. Douglas; Ding, Haiming

2011-01-01

Avocado (Persea americana) fruits are consumed as part of the human diet and extracts have shown growth inhibitory effects in various types of human cancer cells, although the effectiveness of individual components and their underlying mechanism are poorly understood. Using activity-guided fractionation of the flesh of avocado fruits, a chloroform-soluble extract (D003), was identified that exhibited high efficacy towards premalignant and malignant human oral cancer cell lines. From this extract, two aliphatic acetogenins of previously known structure were isolated, compounds 1 [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] and 2 [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate]. In this study, we show for the first time that the growth inhibitory efficacy of this chloroform extract is due to blocking the phosphorylation of EGFR (Tyr1173), c-RAF (Ser338), and ERK1/2 (Thr202/Tyr204) in the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. Compound 1 and 2 both inhibited phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). Compound 2, but not compound 1, prevented EGF-induced activation of EGFR (Tyr1173). When compounds 1 and 2 were combined they synergistically inhibited c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204) phosphorylation, and human oral cancer cell proliferation. The present data suggest that the potential anticancer activity of avocado fruits is due to a combination of specific aliphatic acetogenins that target two key components of the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. PMID:21596018

Reactivation of organophosphate-inhibited human acetylcholinesterase by isonitrosoacetone (MINA): a kinetic analysis.

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Worek, Franz; Thiermann, Horst

2011-11-15

Treatment of poisoning by highly toxic organophosphorus compounds (OP) with atropine and an acetylcholinesterase (AChE) reactivator (oxime) is of limited effectiveness in case of different nerve agents and pesticides. One challenge is the reactivation of OP-inhibited brain AChE which shows inadequate success with charged pyridinium oximes. Recent studies with high doses of the tertiary oxime isonitrosoacetone (MINA) indicated a beneficial effect on central and peripheral AChE and on survival in nerve agent poisoned guinea pigs. Now, an in vitro study was performed to determine the reactivation kinetics of MINA with tabun-, sarin-, cyclosarin-, VX- and paraoxon-inhibited human AChE. MINA showed an exceptionally low affinity to inhibited AChE but, with the exception of tabun-inhibited AChE, a moderate to high reactivity. In comparison to the pyridinium oximes obidoxime, 2-PAM and HI-6 the affinity and reactivity of MINA was in most cases lower and in relation to the most effective reactivators, the second order reactivation constant of MINA was 500 to 3400-fold lower. Hence, high in vivo MINA concentrations would be necessary to achieve at least partial reactivation. This assumption corresponds to in vivo data showing a dose-dependent effect on reactivation and survival in animals. In view, of the toxic potential of MINA in animals human studies would be necessary to determine the tolerability and pharmacokinetics of MINA in order to enable a proper assessment of the value of this oxime as an antidote in OP poisoning. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Inhibition of thioredoxin reductase but not of glutathione reductase by the major classes of alkylating and platinum-containing anticancer compounds.

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Witte, Anne-Barbara; Anestål, Karin; Jerremalm, Elin; Ehrsson, Hans; Arnér, Elias S J

2005-09-01

Mammalian thioredoxin reductase (TrxR) is important for cell proliferation, antioxidant defense, and redox signaling. Together with glutathione reductase (GR) it is the main enzyme providing reducing equivalents to many cellular processes. GR and TrxR are flavoproteins of the same enzyme family, but only the latter is a selenoprotein. With the active site containing selenocysteine, TrxR may catalyze reduction of a wide range of substrates, but can at the same time easily be targeted by electrophilic compounds due to the extraordinarily high reactivity of a selenolate moiety. Here we addressed the inhibition of the enzyme by major anticancer alkylating agents and platinum-containing compounds and we compared it to that of GR. We confirmed prior studies suggesting that the nitrosourea carmustine can inhibit both GR and TrxR. We next found, however, that nitrogen mustards (chlorambucil and melphalan) and alkyl sulfonates (busulfan) efficiently inhibited TrxR while these compounds, surprisingly, did not inhibit GR. Inhibitions were concentration and time dependent and apparently irreversible. Anticancer anthracyclines (daunorubicin and doxorubicin) were, in contrast to the alkylating agents, not inhibitors but poor substrates of TrxR. We also found that TrxR, but not GR, was efficiently inhibited by both cisplatin, its monohydrated complex, and oxaliplatin. Carboplatin, in contrast, could not inhibit any of the two enzymes. These findings lead us to conclude that representative compounds of the major classes of clinically used anticancer alkylating agents and most platinum compounds may easily target TrxR, but not GR. The TrxR inhibition should thereby be considered as a factor that may contribute to the cytotoxicity seen upon clinical use of these drugs.

Human Acid β-Glucosidase Inhibition by Carbohydrate Derived Iminosugars: Towards New Pharmacological Chaperones for Gaucher Disease.

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Parmeggiani, Camilla; Catarzi, Serena; Matassini, Camilla; D'Adamio, Giampiero; Morrone, Amelia; Goti, Andrea; Paoli, Paolo; Cardona, Francesca

2015-09-21

A collection of carbohydrate-derived iminosugars belonging to three structurally diversified sub-classes (polyhydroxylated pyrrolidines, piperidines, and pyrrolizidines) was evaluated for inhibition of human acid β-glucosidase (glucocerebrosidase, GCase), the deficient enzyme in Gaucher disease. The synthesis of several new pyrrolidine analogues substituted at the nitrogen or α-carbon atom with alkyl chains of different lengths suggested an interpretation of the inhibition data and led to the discovery of two new GCase inhibitors at sub-micromolar concentration. In the piperidine iminosugar series, two N-alkylated derivatives were found to rescue the residual GCase activity in N370S/RecNcil mutated human fibroblasts (among which one up to 1.5-fold). This study provides the starting point for the identification of new compounds in the treatment of Gaucher disease. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Peptide inhibition of human cytomegalovirus infection

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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 �

Compound K induced apoptosis via endoplasmic reticulum Ca2+ release through ryanodine receptor in human lung cancer cells

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Dong-Hyun Shin

2018-04-01

Full Text Available Background: Extended endoplasmic reticulum (ER stress may initiate apoptotic pathways in cancer cells, and ER stress has been reported to possibly increase tumor death in cancer therapy. We previously reported that caspase-8 played an important role in compound K-induced apoptosis via activation of caspase-3 directly or indirectly through Bid cleavage, cytochrome c release, and caspase-9 activation in HL-60 human leukemia cells. The mechanisms leading to apoptosis in A549 and SK-MES-1 human lung cancer cells and the role of ER stress have not yet been understood. Methods: The apoptotic effects of compound K were analyzed using flow cytometry, and the changes in protein levels were determined using Western blot analysis. The intracellular calcium levels were monitored by staining with Fura-2/AM and Fluo-3/AM. Results: Compound K-induced ER stress was confirmed through increased phosphorylation of eIF2α and protein levels of GRP78/BiP, XBP-1S, and IRE1α in human lung cancer cells. Moreover, compound-K led to the accumulation of intracellular calcium and an increase in m-calpain activities that were both significantly inhibited by pretreatment either with BAPTA-AM (an intracellular Ca2+ chelator or dantrolene (an RyR channel antagonist. These results were correlated with the outcome that compound K induced ER stress-related apoptosis through caspase-12, as z-ATAD-fmk (a specific inhibitor of caspase-12 partially ameliorated this effect. Interestingly, 4-PBA (ER stress inhibitor dramatically improved the compound K-induced apoptosis. Conclusion: Cell survival and intracellular Ca2+ homeostasis during ER stress in human lung cancer cells are important factors in the induction of the compound K-induced apoptotic pathway. Keywords: apoptosis, calcium, compound K, ER stress, lung cancer cells

DNA polymerase gamma inhibition by vitamin K3 induces mitochondria-mediated cytotoxicity in human cancer cells.

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Sasaki, Ryohei; Suzuki, Yoko; Yonezawa, Yuko; Ota, Yosuke; Okamoto, Yoshiaki; Demizu, Yusuke; Huang, Peng; Yoshida, Hiromi; Sugimura, Kazuro; Mizushina, Yoshiyuki

2008-05-01

Among the vitamin K (VK) compounds, VK3 exhibits distinct cytotoxic activity in cancer cells and is thought to affect redox cycling; however, the underlying mechanisms remain unclear. Here we demonstrate that VK3 selectively inhibits DNA polymerase (pol) gamma, the key enzyme responsible for mitochondrial DNA replication and repair. VK3 at 30 microM inhibited pol gamma by more than 80%, caused impairment of mitochondrial DNA replication and repair, and induced a significant increase in reactive oxygen species (ROS), leading to apoptosis. At a lower concentration (3 microM), VK3 did not cause a significant increase in ROS, but was able to effectively inhibit cell proliferation, which could be reversed by supplementing glycolytic substrates. The cytotoxic action of VK3 was independent of p53 tumor suppressor gene status. Interestingly, VK3 only inhibited pol gamma but did not affect other pol including human pol alpha, pol beta, pol delta, and pol epsilon. VK1 and VK2 exhibited no inhibitory effect on any of the pol tested. These data together suggest that the inhibition of pol gamma by VK3 is relatively specific, and that this compound seems to exert its anticancer activity by two possible mechanisms in a concentration-dependent manner: (1) induction of ROS-mediated cell death at high concentrations; and (2) inhibition of cell proliferation at lower concentrations likely through the suppression of mitochondrial respiratory function. These findings may explain various cytotoxic actions induced by VK3, and may pave the way for the further use of VK3.

Curcumin Inhibits Growth of Human NCI-H292 Lung Squamous Cell Carcinoma Cells by Increasing FOXA2 Expression

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Lingling Tang

2018-02-01

Full Text Available Lung squamous cell carcinoma (LSCC is a common histological lung cancer subtype, but unlike lung adenocarcinoma, limited therapeutic options are available for treatment. Curcumin, a natural compound, may have anticancer effects in various cancer cells, but how it may be used to treat LSCC has not been well studied. Here, we applied curcumin to a human NCI-H292 LSCC cell line to test anticancer effects and explored underlying potential mechanisms of action. Curcumin treatment inhibited NCI-H292 cell growth and increased FOXA2 expression in a time-dependent manner. FOXA2 expression was decreased in LSCC tissues compared with adjacent normal tissues and knockdown of FOXA2 increased NCI-H292 cells proliferation. Inhibition of cell proliferation by curcumin was attenuated by FOXA2 knockdown. Moreover inhibition of STAT3 pathways by curcumin increased FOXA2 expression in NCI-H292 cells whereas a STAT3 activator (IL-6 significantly inhibited curcumin-induced FOXA2 expression. Also, SOCS1 and SOCS3, negative regulators of STAT3 activity, were upregulated by curcumin treatment. Thus, curcumin inhibited human NCI-H292 cells growth by increasing FOXA2 expression via regulation of STAT3 signaling pathways.

Multivalent dendrimeric compounds containing carbohydrates expressed on immune cells inhibit infection by primary isolates of HIV-1

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Borges, Andrew Rosa; Wieczorek, Lindsay; Johnson, Benitra; Benesi, Alan J.; Brown, Bruce K.; Kensinger, Richard D.; Krebs, Fred C.; Wigdahl, Brian; Blumenthal, Robert; Puri, Anu; McCutchan, Francine E.; Birx, Deborah L.; Polonis, Victoria R.; Schengrund, Cara-Lynne

2010-01-01

Specific glycosphingolipids (GSL), found on the surface of target immune cells, are recognized as alternate cell surface receptors by the human immunodeficiency virus type 1 (HIV-1) external envelope glycoprotein. In this study, the globotriose and 3’-sialyllactose carbohydrate head groups found on two GSL were covalently attached to a dendrimer core to produce two types of unique multivalent carbohydrates (MVC). These MVC inhibited HIV-1 infection of T cell lines and primary peripheral blood mononuclear cells (PBMC) by T cell line-adapted viruses or primary isolates, with IC50s ranging from 0.1 – 7.4 µg/ml. Inhibition of Env-mediated membrane fusion by MVC was also observed using a dye-transfer assay. These carbohydrate compounds warrant further investigation as a potential new class of HIV-1 entry inhibitors. The data presented also shed light on the role of carbohydrate moieties in HIV-1 virus-host cell interactions. PMID:20880566

An Insecticidal Compound Produced by an Insect-Pathogenic Bacterium Suppresses Host Defenses through Phenoloxidase Inhibition

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Ihsan Ullah

2014-12-01

Full Text Available A bioassay-guided column chromatographic strategy was adopted in the present study to fractionate the culture extract of Photorhabdus temperata M1021 to identify potential insecticidal and antimicrobial compounds. An ethyl acetate (EtOAc culture extract of P. temperata was assayed against Galleria mellonella larvae through intra-hemocoel injection and exhibited 100% insect mortality within 60 h. The EtOAc fraction and an isolated compound exhibited phenoloxidase (PO inhibition of up to 60% and 63%, respectively. The compound was identified as 1,2-benzenedicarboxylic acid (phthalic acid, PA by gas chromatography-mass spectrometry and nuclear magnetic resonance. PA exhibited insecticidal activity against G. mellonella in a dose-dependent manner, and 100% insect mortality was observed at 108 h after injection of 1 M PA. In a PO inhibition assay, 0.5 and 1 M concentrations of PA were found to inhibit PO activity by 74% and 82%, respectively; and in a melanotic nodule formation assay, nodule formation was significantly inhibited (27 and 10 nodules by PA (0.5 and 1 M, respectively. PA was furthermore found to have substantial antioxidant activity and maximum antioxidant activity was 64.7% for 0.5 M PA as compare to control. Antibacterial activity was assessed by The MIC values ranged from 0.1 M to 0.5 M of PA. This study reports a multifunctional PA, a potential insecticidal agent, could a factor of insect mortality along with other toxins produced by P. temperata M1021.

Semicarbazone EGA Inhibits Uptake of Diphtheria Toxin into Human Cells and Protects Cells from Intoxication

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Leonie Schnell

2016-07-01

Full Text Available Diphtheria toxin is a single-chain protein toxin that invades human cells by receptor-mediated endocytosis. In acidic endosomes, its translocation domain inserts into endosomal membranes and facilitates the transport of the catalytic domain (DTA from endosomal lumen into the host cell cytosol. Here, DTA ADP-ribosylates elongation factor 2 inhibits protein synthesis and leads to cell death. The compound 4-bromobenzaldehyde N-(2,6-dimethylphenylsemicarbazone (EGA has been previously shown to protect cells from various bacterial protein toxins which deliver their enzymatic subunits from acidic endosomes to the cytosol, including Bacillus anthracis lethal toxin and the binary clostridial actin ADP-ribosylating toxins C2, iota and Clostridium difficile binary toxin (CDT. Here, we demonstrate that EGA also protects human cells from diphtheria toxin by inhibiting the pH-dependent translocation of DTA across cell membranes. The results suggest that EGA might serve for treatment and/or prevention of the severe disease diphtheria.

Acrolein in cigarette smoke inhibits T-cell responses.

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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.

A-Type Cranberry Proanthocyanidins Inhibit the RANKL-Dependent Differentiation and Function of Human Osteoclasts

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Amy B. Howell

2011-03-01

Full Text Available This study investigated the effect of A-type cranberry proanthocyanidins (AC-PACs on osteoclast formation and bone resorption activity. The differentiation of human pre-osteoclastic cells was assessed by tartrate-resistant acid phosphatase (TRAP staining, while the secretion of interleukin-8 (IL-8 and matrix metalloproteinases (MMPs was measured by ELISA. Bone resorption activity was investigated by using a human bone plate coupled with an immunoassay that detected the release of collagen helical peptides. AC-PACs up to 100 µg/mL were atoxic for osteoclastic cells. TRAP staining evidenced a dose-dependent inhibition of osteoclastogenesis. More specifically, AC-PACs at 50 µg/mL caused a 95% inhibition of RANKL-dependent osteoclast differentiation. This concentration of AC-PACs also significantly increased the secretion of IL-8 (6-fold and inhibited the secretion of both MMP-2 and MMP-9. Lastly, AC-PACs (10, 25, 50 and 100 µg/ml affected bone degradation mediated by mature osteoclasts by significantly decreasing the release of collagen helical peptides. This study suggests that AC-PACs can interfere with osteoclastic cell maturation and physiology as well as prevent bone resorption. These compounds may be considered as therapeutic agents for the prevention and treatment of periodontitis.

Inhibition of biofilm formation, quorum sensing and infection in Pseudomonas aeruginosa by natural products-inspired organosulfur compounds.

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Nathaniel C Cady

Full Text Available Using a microplate-based screening assay, the effects on Pseudomonas aeruginosa PAO1 biofilm formation of several S-substituted cysteine sulfoxides and their corresponding disulfide derivatives were evaluated. From our library of compounds, S-phenyl-L-cysteine sulfoxide and its breakdown product, diphenyl disulfide, significantly reduced the amount of biofilm formation by P. aeruginosa at levels equivalent to the active concentration of 4-nitropyridine-N-oxide (NPO (1 mM. Unlike NPO, which is an established inhibitor of bacterial biofilms, our active compounds did not reduce planktonic cell growth and only affected biofilm formation. When used in a Drosophila-based infection model, both S-phenyl-L-cysteine sulfoxide and diphenyl disulfide significantly reduced the P. aeruginosa recovered 18 h post infection (relative to the control, and were non-lethal to the fly hosts. The possibility that the observed biofilm inhibitory effects were related to quorum sensing inhibition (QSI was investigated using Escherichia coli-based reporters expressing P. aeruginosa lasR or rhIR response proteins, as well as an endogenous P. aeruginosa reporter from the lasI/lasR QS system. Inhibition of quorum sensing by S-phenyl-L-cysteine sulfoxide was observed in all of the reporter systems tested, whereas diphenyl disulfide did not exhibit QSI in either of the E. coli reporters, and showed very limited inhibition in the P. aeruginosa reporter. Since both compounds inhibit biofilm formation but do not show similar QSI activity, it is concluded that they may be functioning by different pathways. The hypothesis that biofilm inhibition by the two active compounds discovered in this work occurs through QSI is discussed.

Identification of Compounds That Inhibit IGF-I Signaling in Hyperglycemia

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Laura A. Maile

2009-01-01

Full Text Available Increased responsiveness of vascular cells to the growth factor IGF-I has been implicated in complications associated with diabetes. Here we describe the development of an assay and screening of a library of compounds for their ability to accelerate cleavage of the transmembrane protein integrin-associated protein (IAP thereby disrupting the association between IAP and SHPS-1 which we have shown as critical for the enhanced response of vascular cells to IGF-I. The cell-based ELISA utilizes an antibody that specifically detects cleaved, but not intact, IAP. Of the 1040 compounds tested, 14 were considered active by virtue of their ability to stimulate an increase in antibody-binding indicative of IAP cleavage. In experiments with smooth muscle and retinal endothelial cell cultures in hyperglycemic conditions, each active compound was shown to accelerate the cleavage of IAP, and this was associated with a decrease in IAP association with SHPS-1 as determined by coimmunoprecipitation of the proteins from cell lysates. As a consequence of the acceleration in IAP cleavage, the compounds were shown to inhibit IGF-I-stimulated phosphorylation of key signaling molecules including Shc and ERK1/2, and this in turn was associated with a decrease in IGF-I-stimulated cell proliferation. Identification of these compounds that utilize this mechanism has the potential to yield novel therapeutic approaches for the prevention and treatment of vascular complications associated with diabetes.

Studies on Inhibition of Proliferation of Enterovirus-71 by Compound YZ-LY-0.

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Yang, Qingzhan; Jie, Qing; Shaw, Neil; Li, Lei; Rao, Zihe; Yin, Zheng; Lou, Zhiyong

2015-01-01

In recent years, hand-foot-and-mouth disease (HFMD), which is caused by Enteroviruses, has emerged as a serious illness. It affects mainly children under the age of five and results in high fatality rates. Enterovirus 71 (EV71) is the main causative agent of HFMD in China and currently there are no effective anti-viral drugs available to treat HFMD. In the present study, we screened compounds for inhibition of proliferation of EV71. Compound YZ-LY-0 stalled the life cycle of EV71. The inhibitor exhibited EC50 value of 0.29 μm against SK-EV006 strain of EV71. Notably, YZ-LY-0 had low cytotoxicity (CC50 > 100 μM) and a high selectivity index (over 300) in Vero and RD cells. YZ-LY-0 in combination with an EV71 RdRp inhibitor or an entry inhibitor showed an antagonistic effect at very low concentrations. However, at higher concentrations the inhibitors exhibited a synergistic effect in inhibiting viral replication. Preliminary results on investigation of the mechanism of inhibition indicate that YZ-LY-0 does not block the entry of the virus in the host cell, but instead inhibits an early stage of EV71 replication. Our studies provide a potential clinical therapeutic option against EV71 infections and suggest that a combined application of YZ-LY-0 with other inhibitors could be more effective in the treatment of HFMD.

Screening of plant extracts for human tyrosinase inhibiting effects.

Science.gov (United States)

Kim, M; Park, J; Song, K; Kim, H G; Koh, J-S; Boo, Y C

2012-04-01

Screening for tyrosinase (TYR) inhibitors potentially useful for control of skin pigmentation has been hampered by the limited availability of human TYR. To overcome this hurdle, we have established human embryonic kidney (HEK293)-TYR cells that constitutively express human TYR. In the current study, we assayed human TYR inhibition activities of 50 plant extracts using the lysates of transformed HEK293-TYR cells. The strongest inhibition of human TYR was shown by the extract of Vaccinium bracteatum Thunberg, followed by the extract of Morus bombycis Koidzumi. The former extract did not inhibit mushroom TYR activity whereas significant inhibition was observed with the latter extract, demonstrating the importance of using human TYR in the screening for human TYR inhibitors. Upon liquid-liquid partitioning of the extract from V. bracteatum, the active constituents were enriched in the ethyl acetate fraction, and the subsequent preparatory thin-layer chromatography identified p-coumaric acid (PCA) as the main active constituent. The hypo-pigmentation of PCA was verified in the MelanoDerm™ Skin Model. This study demonstrates that transformed HEK293-TYR cells could expedite the discovery of human TYR-specific inhibitors from natural sources which might be useful in the control of skin pigmentation. © 2012 The Authors. ICS © 2012 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

The Natural Antiangiogenic Compound AD0157 Induces Caspase-Dependent Apoptosis in Human Myeloid Leukemia Cells

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Melissa García-Caballero

2017-11-01

Full Text Available Evasion of apoptosis is a hallmark of cancer especially relevant in the development and the appearance of leukemia drug resistance mechanisms. The development of new drugs that could trigger apoptosis in aggressive hematological malignancies, such as AML and CML, may be considered a promising antileukemic strategy. AD0157, a natural marine pyrrolidinedione, has already been described as a compound that inhibits angiogenesis by induction of apoptosis in endothelial cells. The crucial role played by defects in the apoptosis pathways in the pathogenesis, progression and response to conventional therapies of several forms of leukemia, moved us to analyze the effect of this compound on the growth and death of leukemia cells. In this work, human myeloid leukemia cells (HL60, U937 and KU812F were treated with AD0157 ranging from 1 to 10 μM and an experimental battery was applied to evaluate its apoptogenic potential. We report here that AD0157 was highly effective to inhibit cell growth by promotion of apoptosis in human myeloid leukemia cells, and provide evidence of its mechanisms of action. The apoptogenic activity of AD0157 on leukemia cells was verified by an increased chromatin condensation and DNA fragmentation, and confirmed by an augmentation in the apoptotic subG1 population, translocation of the membrane phosphatidylserine from the inner face of the plasma membrane to the cell surface and by cleavage of the apoptosis substrates PARP and lamin-A. In addition, AD0157 in the low micromolar range significantly enhanced the activities of the initiator caspases-8 and -9, and the effector caspases-3/-7 in a dose-dependent manner. Results presented here throw light on the apoptogenic mechanism of action of AD0157, mediated through caspase-dependent cascades, with an especially relevant role played by mitochondria. Altogether, these results suggest the therapeutic potential of this compound for the treatment of human myeloid leukemia.

Lasiodin inhibits proliferation of human nasopharyngeal carcinoma cells by simultaneous modulation of the Apaf-1/caspase, AKT/MAPK and COX-2/NF-κB signaling pathways.

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Lianzhu Lin

Full Text Available Rabdosia serra has been widely used for the treatment of the various human diseases. However, the antiproliferative effects and underlying mechanisms of the compounds in this herb remain largely unknown. In this study, an antiproliferative compound against human nasopharyngeal carcinoma (NPC cells from Rabdosia serra was purified and identified as lasiodin (a diterpenoid. The treatment with lasiodin inhibited cell viability and migration. Lasiodin also mediated the cell morphology change and induced apoptosis in NPC cells. The treatment with lasiodin induced the Apaf-1 expression, triggered the cytochrome-C release, and stimulated the PARP, caspase-3 and caspase-9 cleavages, thereby activating the apoptotic pathways. The treatment with lasiodin also significantly inhibited the phosphorylations of the AKT, ERK1/2, p38 and JNK proteins. The pretreatment with the AKT or MAPK-selective inhibitors considerably blocked the lasiodin-mediated inhibition of cell proliferation. Moreover, the treatment with lasiodin inhibited the COX-2 expression, abrogated NF-κB binding to the COX-2 promoter, and promoted the NF-κB translocation from cell nuclei to cytosol. The pretreatment with a COX-2-selective inhibitor abrogated the lasiodin-induced inhibition of cell proliferation. These results indicated that lasiodin simultaneously activated the Apaf-1/caspase-dependent apoptotic pathways and suppressed the AKT/MAPK and COX-2/NF-κB signaling pathways. This study also suggested that lasiodin could be a promising natural compound for the prevention and treatment of NPC.

Efficacy of a novel antiviral compound to inhibit replication of multiple pestivirus species

Science.gov (United States)

The pestiviruses are economically important pathogens of livestock. An aromatic cationic compound (DB772) has previously been shown to inhibit bovine viral diarrhea virus (BVDV) type 1 in vitro at concentrations lacking cytotoxic side effects. The aim of this study was to determine the scope of anti...

Mechanism of inhibition of catalase by nitro and nitroso compounds.

Science.gov (United States)

Titov, V Yu; Petrenko, Yu M; Vanin, A F

2008-01-01

Dinitrosyl iron complexes (DNIC) with thiolate ligands and S-nitrosothiols, which are NO and NO+ donors, share the earlier demonstrated ability of nitrite for inhibition of catalase. The efficiency of inhibition sharply (by several orders in concentration of these agents) increases in the presence of chloride, bromide, and thiocyanate. The nitro compounds tested--nitroarginine, nitroglycerol, nitrophenol, and furazolidone--gained the same inhibition ability after incubation with ferrous ions and thiols. This is probably the result of their transformation into DNIC. None of these substances lost the inhibitory effect in the presence of the well known NO scavenger oxyhemoglobin. This fact suggests that NO+ ions rather than neutral NO molecules are responsible for the enzyme inactivation due to nitrosation of its structures. The enhancement of catalase inhibition in the presence of halide ions and thiocyanate might be caused by nitrosyl halide formation. The latter protected nitrosonium ions against hydrolysis, thereby ensuring their transfer to the targets in enzyme molecules. The addition of oxyhemoglobin plus iron chelator o-phenanthroline destroying DNIC sharply attenuated the inhibitory effect of DNIC on catalase. o-Phenanthroline added alone did not influence this effect. Oxyhemoglobin is suggested to scavenge nitrosonium ions released from decomposing DNIC, thereby preventing catalase nitrosation. The mixture of oxyhemoglobin and o-phenanthroline did not affect the inhibitory action of nitrite or S-nitrosothiols on catalase.

Aliphatic acetogenin constituents of avocado fruits inhibit human oral cancer cell proliferation by targeting the EGFR/RAS/RAF/MEK/ERK1/2 pathway

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D' Ambrosio, Steven M. [Department of Radiology, College of Medicine, The Ohio State University, Columbus, OH 43210 (United States); Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210 (United States); Han, Chunhua [Department of Radiology, College of Medicine, The Ohio State University, Columbus, OH 43210 (United States); Pan, Li; Douglas Kinghorn, A. [Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210 (United States); Ding, Haiming, E-mail: ding.29@osu.edu [Department of Radiology, College of Medicine, The Ohio State University, Columbus, OH 43210 (United States)

2011-06-10

Highlights: {yields} The aliphatic acetogenins [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] (1) and [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate] (2) isolated from avocado fruit inhibit phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). {yields} Aliphatic acetogenin 2, but not 1, prevents EGF-induced activation of EGFR (Tyr1173). {yields} Combination of both aliphatic acetogenins synergistically inhibits c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204) phosphorylation and human oral cancer cell proliferation. {yields} The potential anticancer activity of avocado fruits is due to a combination of specific aliphatic acetogenins targeting two key components of the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. {yields} Providing a double hit on a critical cancer pathway such as EGFR/RAS/RAF/MEK/ERK1/2 by phytochemicals like those found in avocado fruit could lead to more effective approach toward cancer prevention. -- Abstract: Avocado (Persea americana) fruits are consumed as part of the human diet and extracts have shown growth inhibitory effects in various types of human cancer cells, although the effectiveness of individual components and their underlying mechanism are poorly understood. Using activity-guided fractionation of the flesh of avocado fruits, a chloroform-soluble extract (D003) was identified that exhibited high efficacy towards premalignant and malignant human oral cancer cell lines. From this extract, two aliphatic acetogenins of previously known structure were isolated, compounds 1 [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] and 2 [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate]. In this study, we show for the first time that the growth inhibitory efficacy of this chloroform extract is due to blocking the phosphorylation of EGFR (Tyr1173), c-RAF (Ser338), and ERK1/2 (Thr202/Tyr204) in the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. Compounds 1 and 2 both inhibited phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). Compound 2, but not

Aliphatic acetogenin constituents of avocado fruits inhibit human oral cancer cell proliferation by targeting the EGFR/RAS/RAF/MEK/ERK1/2 pathway

International Nuclear Information System (INIS)

D'Ambrosio, Steven M.; Han, Chunhua; Pan, Li; Douglas Kinghorn, A.; Ding, Haiming

2011-01-01

Highlights: → The aliphatic acetogenins [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] (1) and [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate] (2) isolated from avocado fruit inhibit phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). → Aliphatic acetogenin 2, but not 1, prevents EGF-induced activation of EGFR (Tyr1173). → Combination of both aliphatic acetogenins synergistically inhibits c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204) phosphorylation and human oral cancer cell proliferation. → The potential anticancer activity of avocado fruits is due to a combination of specific aliphatic acetogenins targeting two key components of the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. → Providing a double hit on a critical cancer pathway such as EGFR/RAS/RAF/MEK/ERK1/2 by phytochemicals like those found in avocado fruit could lead to more effective approach toward cancer prevention. -- Abstract: Avocado (Persea americana) fruits are consumed as part of the human diet and extracts have shown growth inhibitory effects in various types of human cancer cells, although the effectiveness of individual components and their underlying mechanism are poorly understood. Using activity-guided fractionation of the flesh of avocado fruits, a chloroform-soluble extract (D003) was identified that exhibited high efficacy towards premalignant and malignant human oral cancer cell lines. From this extract, two aliphatic acetogenins of previously known structure were isolated, compounds 1 [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] and 2 [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate]. In this study, we show for the first time that the growth inhibitory efficacy of this chloroform extract is due to blocking the phosphorylation of EGFR (Tyr1173), c-RAF (Ser338), and ERK1/2 (Thr202/Tyr204) in the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. Compounds 1 and 2 both inhibited phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). Compound 2, but not compound 1, prevented EGF

The Hall-Rodriguez theory of latent inhibition: Further assessment of compound stimulus preexposure effects.

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Rodríguez, Gabriel; Márquez, Raúl; Gil, Marta; Alonso, Gumersinda; Hall, Geoffrey

2014-10-01

According to a recent theory (Hall & Rodriguez, 2010), the latent inhibition produced by nonreinforced exposure to a target stimulus (B) will be deepened by subsequent exposure of that stimulus in compound with another (AB). This effect of compound exposure is taken to depend on the addition of a novel A to the familiar B and is not predicted for equivalent preexposure on which AB trials precede the A trials. This prediction was tested in 2 experiments using rats. Experiment 1 used an aversive procedure with flavors as the stimuli; Experiment 2 used an appetitive procedure with visual and auditory stimuli. In both, we found that conditioning with B as the conditioned stimulus proceeded more slowly (i.e., latent inhibition was greater) in subjects given the B-AB sequence in preexposure than in subjects given the AB-B sequence.

Inhibition of DNA replication and repair by anthralin or danthron in cultured human cells

International Nuclear Information System (INIS)

Clark, J.M.; Hanawalt, P.C.

1982-01-01

The comparative effects of the tumor promoter anthralin and its analog, danthron, on semiconservative DNA replication and DNA repair synthesis were studied in cultured human cells. Bromodeoxyuridine was used as density label together with 3 H-thymidine to distinguish replication from repair synthesis in isopycnic CsCl gradients. Anthralin at 1.1 microgram inhibited replication in T98G cells by 50%. In cells treated with 0.4 or 1.3 microM anthralin and additive effect was observed on the inhibition of replication by ultraviolet light (254 nm). In cells irradiated with 20 J/m2, 2.3 microM anthralin was required to inhibit repair synthesis by 50%. Thus there was no selective inhibitory effect of anthralin on repair synthesis. Danthron exhibited no detectable effect on either semiconservative replication or repair synthesis at concentrations below about 5.0 microM. Neither compound stimulated repair synthesis in the absence of ultraviolet irradiation. Thus, anthralin and danthron do not appear to react with DNA to form adducts that are subject to excision repair. Although both compounds appear to intercalate into supercoiled DNA in vitro to a limited extent, the degree of unwinding introduced by the respective drugs does not correlate with their relative effects on DNA synthesis in vivo. Therefore the inhibitory effect of anthralin on DNA replication and repair synthesis in T98G cells does not appear to result from the direct interaction of the drug with DNA

Automated evaluation of pharmaceutically active ionic liquids’ (eco)toxicity through the inhibition of human carboxylesterase and Vibrio fischeri

International Nuclear Information System (INIS)

Costa, Susana P.F.; Justina, Vanessa D.; Bica, Katharina; Vasiloiu, Maria; Pinto, Paula C.A.G.; Saraiva, M. Lúcia M.F.S.

2014-01-01

Highlights: • IL-APIs toxicity on humans and aquatic environment was evaluated by inhibition assays. • The inhibition assays were implemented through automated screening bioassays. • Automation of bioassays enabled a rigorous control of the reaction conditions. • EC 50 obtained provide vital information on IL-APIs safety and potential use as drugs. -- Abstract: The toxicity of 16 pharmaceutical active ionic liquids (IL-APIs) was evaluated by automated approaches based on sequential injection analysis (SIA). The implemented bioassays were centered on the inhibition of human carboxylesterase 2 and Vibrio fischeri, in the presence of the tested compounds. The inhibitory effects were quantified by calculating the inhibitor concentration required to cause 50% of inhibition (EC 50 ). The EC 50 values demonstrated that the cetylpyridinium group was one of the most toxic cations and that the imidazolium group was the less toxic. The obtained results provide important information about the safety of the studied IL-APIs and their possible use as pharmaceutical drugs. The developed automated SIA methodologies are robust screening bioassays, and can be used as a generic tools to identify the (eco)toxicity of the structural elements of ILs, contributing to a sustainable development of drugs

Contamination levels of human pharmaceutical compounds in French surface and drinking water.

Science.gov (United States)

Mompelat, S; Thomas, O; Le Bot, B

2011-10-01

The occurrence of 20 human pharmaceutical compounds and metabolites from 10 representative therapeutic classes was analysed from resource and drinking water in two catchment basins located in north-west France. 98 samples were analysed from 63 stations (surface water and drinking water produced from surface water). Of the 20 human pharmaceutical compounds selected, 16 were quantified in both the surface water and drinking water, with 22% of the values above the limit of quantification for surface water and 14% for drinking water). Psychostimulants, non-steroidal anti-inflammatory drugs, iodinated contrast media and anxiolytic drugs were the main therapeutic classes of human pharmaceutical compounds detected in the surface water and drinking water. The results for surface water were close to results from previous studies in spite of differences in prescription rates of human pharmaceutical compounds in different countries. The removal rate of human pharmaceutical compounds at 11 water treatment units was also determined. Only caffeine proved to be resistant to drinking water treatment processes (with a minimum rate of 5%). Other human pharmaceutical compounds seemed to be removed more efficiently (average elimination rate of over 50%) by adsorption onto activated carbon and oxidation/disinfection with ozone or chlorine (not taking account of the disinfection by-products). These results add to the increasing evidence of the occurrence of human pharmaceutical compounds in drinking water that may represent a threat to human beings exposed to a cocktail of human pharmaceutical compounds and related metabolites and by-products in drinking water.

Inhibition of Human Cytomegalovirus pUL89 Terminase Subunit Blocks Virus Replication and Genome Cleavage.

Science.gov (United States)

Wang, Yan; Mao, Lili; Kankanala, Jayakanth; Wang, Zhengqiang; Geraghty, Robert J

2017-02-01

The human cytomegalovirus terminase complex cleaves concatemeric genomic DNA into unit lengths during genome packaging and particle assembly. This process is an attractive drug target because cleavage of concatemeric DNA is not required in mammalian cell DNA replication, indicating that drugs targeting the terminase complex could be safe and selective. One component of the human cytomegalovirus terminase complex, pUL89, provides the endonucleolytic activity for genome cleavage, and the domain responsible is reported to have an RNase H-like fold. We hypothesize that the pUL89 endonuclease activity is inhibited by known RNase H inhibitors. Using a novel enzyme-linked immunosorbent assay (ELISA) format as a screening assay, we found that a hydroxypyridonecarboxylic acid compound, previously reported to be an inhibitor of human immunodeficiency virus RNase H, inhibited pUL89 endonuclease activity at low-micromolar concentrations. Further characterization revealed that this pUL89 endonuclease inhibitor blocked human cytomegalovirus replication at a relatively late time point, similarly to other reported terminase complex inhibitors. Importantly, this inhibitor also prevented the cleavage of viral genomic DNA in infected cells. Taken together, these results substantiate our pharmacophore hypothesis and validate our ligand-based approach toward identifying novel inhibitors of pUL89 endonuclease. Human cytomegalovirus infection in individuals lacking a fully functioning immune system, such as newborns and transplant patients, can have severe and debilitating consequences. The U.S. Food and Drug Administration-approved anti-human cytomegalovirus drugs mainly target the viral polymerase, and resistance to these drugs has appeared. Therefore, anti-human cytomegalovirus drugs from novel targets are needed for use instead of, or in combination with, current polymerase inhibitors. pUL89 is a viral ATPase and endonuclease and is an attractive target for anti-human cytomegalovirus

Inhibition by TRPA1 agonists of compound action potentials in the frog sciatic nerve

Energy Technology Data Exchange (ETDEWEB)

Matsushita, Akitomo; Ohtsubo, Sena; Fujita, Tsugumi; Kumamoto, Eiichi, E-mail: kumamote@cc.saga-u.ac.jp

2013-04-26

Highlights: •TRPA1 agonists inhibited compound action potentials in frog sciatic nerves. •This inhibition was not mediated by TRPA1 channels. •This efficacy was comparable to those of lidocaine and cocaine. •We found for the first time an ability of TRPA1 agonists to inhibit nerve conduction. -- Abstract: Although TRPV1 and TRPM8 agonists (vanilloid capsaicin and menthol, respectively) at high concentrations inhibit action potential conduction, it remains to be unknown whether TRPA1 agonists have a similar action. The present study examined the actions of TRPA1 agonists, cinnamaldehyde (CA) and allyl isothiocyanate (AITC), which differ in chemical structure from each other, on compound action potentials (CAPs) recorded from the frog sciatic nerve by using the air-gap method. CA and AITC concentration-dependently reduced the peak amplitude of the CAP with the IC{sub 50} values of 1.2 and 1.5 mM, respectively; these activities were resistant to a non-selective TRP antagonist ruthenium red or a selective TRPA1 antagonist HC-030031. The CA and AITC actions were distinct in property; the latter but not former action was delayed in onset and partially reversible, and CA but not AITC increased thresholds to elicit CAPs. A CAP inhibition was seen by hydroxy-α-sanshool (by 60% at 0.05 mM), which activates both TRPA1 and TRPV1 channels, a non-vanilloid TRPV1 agonist piperine (by 20% at 0.07 mM) and tetrahydrolavandulol (where the six-membered ring of menthol is opened; IC{sub 50} = 0.38 mM). It is suggested that TRPA1 agonists as well as TRPV1 and TRPM8 agonists have an ability to inhibit nerve conduction without TRP activation, although their agonists are quite different in chemical structure from each other.

Synergistic chondroprotective effects of curcumin and resveratrol in human articular chondrocytes: inhibition of IL-1beta-induced NF-kappaB-mediated inflammation and apoptosis.

Science.gov (United States)

Csaki, Constanze; Mobasheri, Ali; Shakibaei, Mehdi

2009-01-01

Currently available treatments for osteoarthritis (OA) are restricted to nonsteroidal anti-inflammatory drugs, which exhibit numerous side effects and are only temporarily effective. Thus novel, safe and more efficacious anti-inflammatory agents are needed for OA. Naturally occurring polyphenolic compounds, such as curcumin and resveratrol, are potent agents for modulating inflammation. Both compounds mediate their effects by targeting the NF-kappaB signalling pathway. We have recently demonstrated that in chondrocytes resveratrol modulates the NF-kappaB pathway by inhibiting the proteasome, while curcumin modulates the activation of NF-kappaB by inhibiting upstream kinases (Akt). However, the combinational effects of these compounds in chondrocytes has not been studied and/or compared with their individual effects. The aim of this study was to investigate the potential synergistic effects of curcumin and resveratrol on IL-1beta-stimulated human chondrocytes in vitro using immunoblotting and electron microscopy. Treatment with curcumin and resveratrol suppressed NF-kappaB-regulated gene products involved in inflammation (cyclooxygenase-2, matrix metalloproteinase (MMP)-3, MMP-9, vascular endothelial growth factor), inhibited apoptosis (Bcl-2, Bcl-xL, and TNF-alpha receptor-associated factor 1) and prevented activation of caspase-3. IL-1beta-induced NF-kappaB activation was suppressed directly by cocktails of curcumin and resveratrol through inhibition of Ikappakappa and proteasome activation, inhibition of IkappaBalpha phosphorylation and degradation, and inhibition of nuclear translocation of NF-kappaB. The modulatory effects of curcumin and resveratrol on IL-1beta-induced expression of cartilage specific matrix and proinflammatory enzymes were mediated in part by the cartilage-specific transcription factor Sox-9. We propose that combining these natural compounds may be a useful strategy in OA therapy as compared with separate treatment with each individual

Translational research into species differences of endocrine toxicity via steroidogenesis inhibition by SMP-028 — For human safety in clinical study

International Nuclear Information System (INIS)

Nishizato, Yohei; Imai, Satoki; Okahashi, Noriko; Yabunaka, Atsushi; Kunimatsu, Takeshi; Kikuchi, Kaoru; Yabuki, Masashi

2014-01-01

SMP-028 is a drug candidate developed for the treatment of asthma. In a 13-week repeated dose toxicity study of SMP-028 in rats and monkeys, differences of endocrine toxicological events between rats and monkeys were observed. In rats, these toxicological events mainly consisted of pathological changes in the adrenal, testis, ovary, and the other endocrine-related organs. On the other hand, in monkeys, no toxicological events were observed. The goal of this study is to try to understand the reason why only rats, but not monkeys, showed toxicological events following treatment with SMP-028 and to eventually predict the possible toxicological effect of this compound on human endocrine organs. Our results show that SMP-028 inhibits neutral cholesterol esterase more strongly than other steroidogenic enzymes in rats. Although SMP-028 also inhibits monkeys and human neutral cholesterol esterase, this inhibition is much weaker than that of rat neutral cholesterol esterase. These results indicate (1) that the difference in endocrine toxicological events between rats and monkeys is mainly due to inhibition of steroidogenesis by SMP-028 in rats, not in monkeys, and (2) that SMP-028 may not affect steroidogenesis in humans and therefore might cause no endocrine toxicological events in clinical studies. - Highlights: • SMP-028 inhibits neutral CEase more strongly than other steroidogenic enzymes in rats. • Inhibition of neutral CEase in rats by SMP-028 suppresses steroidogenesis in vivo. • SMP-028 does not inhibit neutral CEase in monkeys in vivo. • Steroidogenesis pathway in monkeys treated with SMP-028 was not suppressed. • SMP-028 may not inhibit LIPE in humans in vivo

Translational research into species differences of endocrine toxicity via steroidogenesis inhibition by SMP-028 — For human safety in clinical study

Energy Technology Data Exchange (ETDEWEB)

Nishizato, Yohei, E-mail: yohei-nishizato@ds-pharma.co.jp [Preclinical Research Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 33-94, Enoki-cho, Suita, Osaka 564-0053 (Japan); Imai, Satoki [Preclinical Research Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 33-94, Enoki-cho, Suita, Osaka 564-0053 (Japan); Okahashi, Noriko [Research Planning and Intelligence, Dainippon Sumitomo Pharma Co., Ltd., 33-94, Enoki-cho, Suita, Osaka 564-0053 (Japan); Yabunaka, Atsushi; Kunimatsu, Takeshi [Preclinical Research Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 33-94, Enoki-cho, Suita, Osaka 564-0053 (Japan); Kikuchi, Kaoru [Innovative Drug Discovery Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 33-94, Enoki-cho, Suita, Osaka 564-0053 (Japan); Yabuki, Masashi [Preclinical Research Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 33-94, Enoki-cho, Suita, Osaka 564-0053 (Japan)

2014-05-01

SMP-028 is a drug candidate developed for the treatment of asthma. In a 13-week repeated dose toxicity study of SMP-028 in rats and monkeys, differences of endocrine toxicological events between rats and monkeys were observed. In rats, these toxicological events mainly consisted of pathological changes in the adrenal, testis, ovary, and the other endocrine-related organs. On the other hand, in monkeys, no toxicological events were observed. The goal of this study is to try to understand the reason why only rats, but not monkeys, showed toxicological events following treatment with SMP-028 and to eventually predict the possible toxicological effect of this compound on human endocrine organs. Our results show that SMP-028 inhibits neutral cholesterol esterase more strongly than other steroidogenic enzymes in rats. Although SMP-028 also inhibits monkeys and human neutral cholesterol esterase, this inhibition is much weaker than that of rat neutral cholesterol esterase. These results indicate (1) that the difference in endocrine toxicological events between rats and monkeys is mainly due to inhibition of steroidogenesis by SMP-028 in rats, not in monkeys, and (2) that SMP-028 may not affect steroidogenesis in humans and therefore might cause no endocrine toxicological events in clinical studies. - Highlights: • SMP-028 inhibits neutral CEase more strongly than other steroidogenic enzymes in rats. • Inhibition of neutral CEase in rats by SMP-028 suppresses steroidogenesis in vivo. • SMP-028 does not inhibit neutral CEase in monkeys in vivo. • Steroidogenesis pathway in monkeys treated with SMP-028 was not suppressed. • SMP-028 may not inhibit LIPE in humans in vivo.

Inhibition of dehydrogenase activity in petroleum refinery wastewater bacteria by phenolic compounds

OpenAIRE

Gideon C. Okpokwasili; Christian Okechukwu Nweke

2010-01-01

The toxicity of phenol, 2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, 2-chlorophenol, 4-chlorophenol, 4-bromophenol and 3,5-dimethylphenol on Pseudomonas, Bacillus and Escherichia species isolated from petroleum refinery wastewater was assessed via inhibition of dehydrogenase enzyme activity. At low concentrations, 2-nitrophenol, 2-chlorophenol, 4-chlorophenol, 4-bromophenol and 3,5-dimethylphenol stimulated dehydrogenase activity and at sufficient concentrations, phenolic compounds inhibi...

Hydrogen-rich water inhibits glucose and α,β -dicarbonyl compound-induced reactive oxygen species production in the SHR.Cg-Leprcp/NDmcr rat kidney

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Katakura Masanori

2012-07-01

Full Text Available Abstract Background Reactive oxygen species (ROS production induced by α,β-dicarbonyl compounds and advanced glycation end products causes renal dysfunction in patients with type 2 diabetes and metabolic syndrome. Hydrogen-rich water (HRW increases the H2 level in blood and tissues, thus reducing oxidative stress in animals as well as humans. In this study, we investigated the effects of HRW on glucose- and α,β-dicarbonyl compound-induced ROS generation in vitro and in vivo. Methods Kidney homogenates from Wistar rats were incubated in vitro with glucose and α,β-dicarbonyl compounds containing HRW, following which ROS levels were measured. In vivo animal models of metabolic syndrome, SHR.Cg-Leprcp/NDmcr rats, were treated with HRW for 16 weeks, following which renal ROS production and plasma and renal α,β-dicarbonyl compound levels were measured by liquid chromatograph mass spectrometer. Results HRW inhibited glucose- and α,β-dicarbonyl compound-induced ROS production in kidney homogenates from Wistar rats in vitro. Furthermore, SHR.Cg-Leprcp/NDmcr rats treated with HRW showed a 34% decrease in ROS production. Moreover, their renal glyoxal, methylglyoxal, and 3-deoxyglucosone levels decreased by 81%, 77%, and 60%, respectively. Positive correlations were found between renal ROS levels and renal glyoxal (r = 0.659, p = 0.008 and methylglyoxal (r = 0.782, p = 0.001 levels. Conclusion These results indicate that HRW inhibits the production of α,β-dicarbonyl compounds and ROS in the kidneys of SHR.Cg-Leprcp/NDmcr rats. Therefore, it has therapeutic potential for renal dysfunction in patient with type 2 diabetes and metabolic syndrome.

Alkaloids from sponge, scaffolds for the inhibition of human immunodeficiency virus (hiv)

KAUST Repository

O'Rourke, Aubrie

2016-05-06

Anti-viral compounds with low cytotoxicity are identified from screening of products found in Red Sea sponges, including the sponge Stylissa carteri. The identified compounds can be brominated pyrrole-2- aminoimidazole alkaloids and derivatives thereof. Specific examples of identified compounds include oroidin, hymenialdisine, and debromohymenialdisine, as well as derivatives thereof. The compounds also can be useful scaffolds or pharmacores for further chemical modification and derivatization. Selected compounds, particularly oroidin, show selective anti-viral HIV-1 activity coupled with reduced cytotoxicity. The compounds can function as HIV reverse-transcriptase inhibitors, and molecular modeling can be used to confirm inhibition.

Alkaloids from the Sponge Stylissa carteri Present Prospective Scaffolds for the Inhibition of Human Immunodeficiency Virus 1 (HIV-1)

KAUST Repository

O’Rourke, Aubrie

2016-02-04

The sponge Stylissa carteri is known to produce a number of secondary metabolites displaying anti-fouling, anti-inflammatory, and anti-cancer activity. However, the anti-viral potential of metabolites produced by S. carteri has not been extensively explored. In this study, an S. carteri extract was HPLC fractionated and a cell based assay was used to evaluate the effects of HPLC fractions on parameters of Human Immunodeficiency Virus (HIV-1) infection and cell viability. Candidate HIV-1 inhibitory fractions were then analyzed for the presence of potential HIV-1 inhibitory compounds by mass spectrometry, leading to the identification of three previously characterized compounds, i.e., debromohymenialdisine (DBH), hymenialdisine (HD), and oroidin. Commercially available purified versions of these molecules were re-tested to assess their antiviral potential in greater detail. Specifically, DBH and HD exhibit a 30%–40% inhibition of HIV-1 at 3.1 μM and 13 μM, respectively; however, both exhibited cytotoxicity. Conversely, oroidin displayed a 50% inhibition of viral replication at 50 μM with no associated toxicity. Additional experimentation using a biochemical assay revealed that oroidin inhibited the activity of the HIV-1 Reverse Transcriptase up to 90% at 25 μM. Taken together, the chemical search space was narrowed and previously isolated compounds with an unexplored anti-viral potential were found. Our results support exploration of marine natural products for anti-viral drug discovery.

Triterpenoids from Ganoderma lucidum inhibit the activation of EBV antigens as telomerase inhibitors.

Science.gov (United States)

Zheng, Dong-Shu; Chen, Liang-Shu

2017-10-01

Nasopharyngeal carcinoma (NPC) is a malignant disease that threatens the health of humans. To find effective agents for the inhibition of Epstein-Barr virus (EBV) infection, which is associated with NPC, a phytochemical investigation of Ganoderma lucidum was carried out in the present study. Five triterpenoids were identified, including ganoderic acid A (compound 1), ganoderic acid B (compound 2), ganoderol B (compound 3), ganodermanontriol (compound 4), and ganodermanondiol (compound 5), on the basis of spectroscopic analysis. An inhibition of EBV antigens activation assay was implemented to elucidate the triterpenoids from G. lucidum and potentially prevent NPC. All the triterpenoids showed significant inhibitory effects on both EBV EA and CA activation at 16 nmol. At 3.2 nmol, all the compounds moderately inhibited the activation of the two antigens. The activity of telomerase was inhibited by these triterpenoids at 10 µM. Molecular docking demonstrated that compound 1 was able to inhibit telomerase as a ligand. In addition, the physicochemical properties of these compounds were calculated to elucidate their drug-like properties. These results provided evidence for the application of these triterpenoids and whole G. lucidum in the treatment of NPC.

Inhibition of human lung cancer cell proliferation and survival by wine

Science.gov (United States)

2014-01-01

Background Compounds of plant origin and food components have attracted scientific attention for use as agents for cancer prevention and treatment. Wine contains polyphenols that were shown to have anti-cancer and other health benefits. The survival pathways of Akt and extracellular signal-regulated kinase (Erk), and the tumor suppressor p53 are key modulators of cancer cell growth and survival. In this study, we examined the effects of wine on proliferation and survival of human Non-small cell lung cancer (NSCLC) cells and its effects on signaling events. Methods Human NSCLC adenocarcinoma A549 and H1299 cells were used. Cell proliferation was assessed by thymidine incorporation. Clonogenic assays were used to assess cell survival. Immunoblotting was used to examine total and phosphorylated levels of Akt, Erk and p53. Results In A549 cells red wine inhibited cell proliferation and reduced clonogenic survival at doses as low as 0.02%. Red wine significantly reduced basal and EGF-stimulated Akt and Erk phosphorylation while it increased the levels of total and phosphorylated p53 (Ser15). Control experiments indicated that the anti-proliferative effects of wine were not mediated by the associated contents of ethanol or the polyphenol resveratrol and were independent of glucose transport into cancer cells. White wine also inhibited clonogenic survival, albeit at a higher doses (0.5-2%), and reduced Akt phosphorylation. The effects of both red and white wine on Akt phosphorylation were also verified in H1299 cells. Conclusions Red wine inhibits proliferation of lung cancer cells and blocks clonogenic survival at low concentrations. This is associated with inhibition of basal and EGF-stimulated Akt and Erk signals and enhancement of total and phosphorylated levels of p53. White wine mediates similar effects albeit at higher concentrations. Our data suggest that wine may have considerable anti-tumour and chemoprevention properties in lung cancer and deserves further

Reactivation of organophosphate-inhibited human, Cynomolgus monkey, swine and guinea pig acetylcholinesterase by MMB-4: A modified kinetic approach

International Nuclear Information System (INIS)

Worek, Franz; Wille, Timo; Aurbek, Nadine; Eyer, Peter; Thiermann, Horst

2010-01-01

Treatment of poisoning by highly toxic organophosphorus compounds (OP, nerve agents) is a continuous challenge. Standard treatment with atropine and a clinically used oxime, obidoxime or pralidoxime is inadequate against various nerve agents. For ethical reasons testing of oxime efficacy has to be performed in animals. Now, it was tempting to investigate the reactivation kinetics of MMB-4, a candidate oxime to replace pralidoxime, with nerve agent-inhibited acetylcholinesterase (AChE) from human and animal origin in order to provide a kinetic basis for the proper assessment of in vivo data. By applying a modified kinetic approach, allowing the use of necessary high MMB-4 concentrations, it was possible to determine the reactivation constants with sarin-, cyclosarin-, VX-, VR- and tabun-inhibited AChE. MMB-4 exhibited a high reactivity and low affinity towards OP-inhibited AChE, except of tabun-inhibited enzyme where MMB-4 had an extremely low reactivity. Species differences between human and animal AChE were low (Cynomolgus) to moderate (swine, guinea pig). Due to the high reactivity of MMB-4 a rapid reactivation of inhibited AChE can be anticipated at adequate oxime concentrations which are substantially higher compared to HI-6. Additional studies are necessary to determine the in vivo toxicity, tolerability and pharmacokinetics of MMB-4 in humans in order to enable a proper assessment of the value of this oxime as an antidote against nerve agent poisoning.

Reactivation of organophosphate-inhibited human, Cynomolgus monkey, swine and guinea pig acetylcholinesterase by MMB-4: a modified kinetic approach.

Science.gov (United States)

Worek, Franz; Wille, Timo; Aurbek, Nadine; Eyer, Peter; Thiermann, Horst

2010-12-15

Treatment of poisoning by highly toxic organophosphorus compounds (OP, nerve agents) is a continuous challenge. Standard treatment with atropine and a clinically used oxime, obidoxime or pralidoxime is inadequate against various nerve agents. For ethical reasons testing of oxime efficacy has to be performed in animals. Now, it was tempting to investigate the reactivation kinetics of MMB-4, a candidate oxime to replace pralidoxime, with nerve agent-inhibited acetylcholinesterase (AChE) from human and animal origin in order to provide a kinetic basis for the proper assessment of in vivo data. By applying a modified kinetic approach, allowing the use of necessary high MMB-4 concentrations, it was possible to determine the reactivation constants with sarin-, cyclosarin-, VX-, VR- and tabun-inhibited AChE. MMB-4 exhibited a high reactivity and low affinity towards OP-inhibited AChE, except of tabun-inhibited enzyme where MMB-4 had an extremely low reactivity. Species differences between human and animal AChE were low (Cynomolgus) to moderate (swine, guinea pig). Due to the high reactivity of MMB-4 a rapid reactivation of inhibited AChE can be anticipated at adequate oxime concentrations which are substantially higher compared to HI-6. Additional studies are necessary to determine the in vivo toxicity, tolerability and pharmacokinetics of MMB-4 in humans in order to enable a proper assessment of the value of this oxime as an antidote against nerve agent poisoning. Copyright © 2010 Elsevier Inc. All rights reserved.

Inhibitory effect of Sphagnum palustre extract and its bioactive compounds on aromatase activity

Directory of Open Access Journals (Sweden)

Hee Jeong Eom

2016-09-01

Full Text Available Sphagnum palustre (a moss has been traditionally used in Korea for the cure of several diseases such as cardiac pain and stroke. In this research, the inhibitory effect of S. palustre on aromatase (cytochrome P450 19, CYP19 activity was studied. [1β-3H] androstenedione was used as a substrate and incubated with S. palustre extract and recombinant human CYP19 in the presence of NADPH. S. palustre extract inhibited aromatase in a concentration-dependent manner (IC50 value: 36.4 ± 8.1 µg/mL. To elucidate the major compounds responsible for the aromatase inhibitory effects of S. palustre extract, nine compounds were isolated from the extract and tested for their inhibition of aromatase activity. Compounds 1, 6, and 7 displayed aromatase inhibition, while the inhibition by the other compounds was negligible.

Inhibition and kinetic studies of lignin degrading enzymes of Ganoderma boninense by naturally occurring phenolic compounds.

Science.gov (United States)

Surendran, Arthy; Siddiqui, Yasmeen; Saud, Halimi Mohd; Ali, Nusaibah Syd; Manickam, Sivakumar

2018-05-22

Lignolytic (Lignin degrading) enzyme, from oil palm pathogen Ganoderma boninense Pat. (Syn G. orbiforme (Ryvarden), is involved in the detoxification and the degradation of lignin in the oil palm and is the rate-limiting step in the infection process of this fungus. Active inhibition of lignin degrading enzymes secreted by G. boninense by various naturally occurring phenolic compounds and estimation of efficiency on pathogen suppression was aimed at. In our work, ten naturally occurring phenolic compounds were evaluated for their inhibitory potential towards the lignolytic enzymes of G.boninense. Additionally, the lignin degrading enzymes were characterised. Most of the peholic compounds exhibited an uncompetitive inhibition towards the lignin degrading enzymes. Benzoic acid was the superior inhibitor to the production of lignin degrading enzymes, when compared between the ten phenolic compounds. The inhibitory potential of the phenolic compounds toward the lignin degrading enzymes are higher than that of the conventional metal ion inhibitor. The lignin degrading enzymes were stable in a wide range of pH but were sensitive to higher to temperature. The study demonstrated the inhibitor potential of ten naturally occurring phenolic compounds toward the lignin degrading enzymes of G. boninense with different efficacies. The study has shed a light towards a new management strategy to control BSR in oil palm. It serves as replacement for the existing chemical control. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Acetylshikonin Inhibits Human Pancreatic PANC-1 Cancer Cell Proliferation by Suppressing the NF-κB Activity.

Science.gov (United States)

Cho, Seok-Cheol; Choi, Bu Young

2015-09-01

Acetylshikonin, a natural naphthoquinone derivative compound, has been used for treatment of inflammation and cancer. In the present study, we have investigated whether acetylshikonin could regulate the NF-κB signaling pathway, thereby leading to suppression of tumorigenesis. We observed that acetylshikonin significantly reduced proliferation of several cancer cell lines, including human pancreatic PANC-1 cancer cells. In addition, acetylshikonin inhibited phorbol 12-myristate 13-acetate (PMA) or tumor necrosis-α (TNF-α)-induced NF-κB reporter activity. Proteome cytokine array and real-time RT-PCR results illustrated that acetylshikonin inhibition of PMA-induced production of cytokines was mediated at the transcriptional level and it was associated with suppression of NF-κB activity and matrix metalloprotenases. Finally, we observed that an exposure of acetylshikonin significantly inhibited the anchorage-independent growth of PANC-1 cells. Together, our results indicate that acetylshikonin could serve as a promising therapeutic agent for future treatment of pancreatic cancer.

Germacrane sesquiterpenes isolated from the rhizome of Curcuma xanthorrhiza Roxb. inhibit UVB-induced upregulation of MMP-1, -2, and -3 expression in human keratinocytes.

Science.gov (United States)

Park, Ji-Hae; Mohamed, Mohamed Antar Aziz; Jung, Ye-Jin; Shrestha, Sabina; Lee, Tae Hoon; Lee, Chang-Ho; Han, Daeseok; Kim, Jiyoung; Baek, Nam-In

2015-10-01

Four sesquiterpenes were isolated from the rhizome of Curcuma xanthorrhiza Roxb.: furanodiene (1), germacrone (2), furanodienone (3), and 13-hydroxygermacrone (4). Importantly, this was the first time compounds 1 and 4 were isolated from this plant. The chemical structures of these compounds were determined using 1D- and 2D-nuclear magnetic resonance, infrared spectroscopy, and electron ionization mass spectrometry analyses. Among the isolated compounds, compounds 2 and 4 inhibited UVB-induced upregulation of the mRNA and protein expression levels of MMP-1, MMP-2, and MMP-3 in human keratinocytes (HaCaT). Moreover, this upregulation occurred in a dose-dependent manner over the range of 1-10 μM for each compound.

Steroid-like compounds in Chinese medicines promote blood circulation via inhibition of Na+/K+ -ATPase.

Science.gov (United States)

Chen, Ronald J Y; Chung, Tse-yu; Li, Feng-yin; Yang, Wei-hung; Jinn, Tzyy-rong; Tzen, Jason T C

2010-06-01

To examine if steroid-like compounds found in many Chinese medicinal products conventionally used for the promotion of blood circulation may act as active components via the same molecular mechanism triggered by cardiac glycosides, such as ouabain. The inhibitory potency of ouabain and the identified steroid-like compounds on Na(+)/K(+)-ATPase activity was examined and compared. Molecular modeling was exhibited for the docking of these compounds to Na(+)/K(+)-ATPase. All the examined steroid-like compounds displayed more or less inhibition on Na(+)/K(+)-ATPase, with bufalin (structurally almost equivalent to ouabain) exhibiting significantly higher inhibitory potency than the others. In the pentacyclic triterpenoids examined, ursolic acid and oleanolic acid were moderate inhibitors of Na(+)/K(+)-ATPase, and their inhibitory potency was comparable to that of ginsenoside Rh2. The relatively high inhibitory potency of ursolic acid or oleanolic acid was due to the formation of a hydrogen bond between its carboxyl group and the Ile322 residue in the deep cavity close to two K(+) binding sites of Na(+)/K(+)-ATPase. Moreover, the drastic difference observed in the inhibitory potency of ouabain, bufalin, ginsenoside Rh2, and pentacyclic triterpenoids is ascribed mainly to the number of hydrogen bonds and partially to the strength of hydrophobic interaction between the compounds and residues around the deep cavity of Na(+)/K(+)-ATPase. Steroid-like compounds seem to contribute to therapeutic effects of many cardioactive Chinese medicinal products. Chinese herbs, such as Prunella vulgaris L, rich in ursolic acid, oleanolic acid and their glycoside derivatives may be adequate sources for cardiac therapy via effective inhibition on Na(+)/K(+)-ATPase.

Thermal treatment and leaching of biochar alleviates plant growth inhibition from mobile organic compounds

Directory of Open Access Journals (Sweden)

Nigel V. Gale

2016-08-01

Full Text Available Recent meta-analyses of plant responses to biochar boast positive average effects of between 10 and 40%. Plant responses, however, vary greatly across systems, and null or negative biochar effects are increasingly reported. The mechanisms responsible for such responses remain unclear. In a glasshouse experiment we tested the effects of three forestry residue wood biochars, applied at five dosages (0, 5, 10, 20, and 50 t/ha to a temperate forest drystic cambisol as direct surface applications and as complete soil mixes on the herbaceous pioneers Lolium multiflorum and Trifolium repens. Null and negative effects of biochar on growth were found in most cases. One potential cause for null and negative plant responses to biochar is plant exposure to mobile compounds produced during pyrolysis that leach or evolve following additions of biochars to soil. In a second glasshouse experiment we examined the effects of simple leaching and heating techniques to ameliorate potentially phytotoxic effects of volatile and leachable compounds released from biochar. We used Solid Phase Microextraction (SPME–gas chromatography–mass spectrometry (GC-MS to qualitatively describe organic compounds in both biochar (through headspace extraction, and in the water leachates (through direct injection. Convection heating and water leaching of biochar prior to application alleviated growth inhibition. Additionally, growth was inhibited when filtrate from water-leached biochar was applied following germination. SPME-GC-MS detected primarily short-chained carboxylic acids and phenolics in both the leachates and solid chars, with relatively high concentrations of several known phytotoxic compounds including acetic acid, butyric acid, 2,4-di-tert-butylphenol and benzoic acid. We speculate that variable plant responses to phytotoxic organic compounds leached from biochars may largely explain negative plant growth responses and also account for strongly species

Isolation, Identification, and Xanthine Oxidase Inhibition Activity of Alkaloid Compound from Peperomia pellucida

Science.gov (United States)

Fachriyah, E.; Ghifari, M. A.; Anam, K.

2018-04-01

The research of the isolation and xanthine oxidation inhibition activity of alkaloid compound from Peperomia pellucida has been carried out. Alkaloid extract is isolated by column chromatography and preparative TLC. Alkaloid isolate is identified spectroscopically by UV-Vis spectrophotometer, FT-IR, and LC-MS/MS. Xanthine oxidase inhibition activity is carried out by in vitro assay. The result showed that the alkaloid isolated probably has piperidine basic structure. The alkaloid isolate has N-H, C-H, C = C, C = O, C-N, C-O-C groups and the aromatic ring. The IC50 values of ethanol and alkaloid extract are 71.6658 ppm and 76.3318 ppm, respectively. Alkaloid extract of Peperomia pellucida showed higher activity than ethanol extract.

New Cinchona Oximes Evaluated as Reactivators of Acetylcholinesterase and Butyrylcholinesterase Inhibited by Organophosphorus Compounds

Directory of Open Access Journals (Sweden)

Maja Katalinić

2017-07-01

Full Text Available For the last six decades, researchers have been focused on finding efficient reactivators of organophosphorus compound (OP-inhibited acetylcholinesterase (AChE and butyrylcholinesterase (BChE. In this study, we have focused our research on a new oxime scaffold based on the Cinchona structure since it was proven to fit the cholinesterases active site and reversibly inhibit their activity. Three Cinchona oximes (C1, C2, and C3, derivatives of the 9-oxocinchonidine, were synthesized and investigated in reactivation of various OP-inhibited AChE and BChE. As the results showed, the tested oximes were more efficient in the reactivation of BChE and they reactivated enzyme activity to up to 70% with reactivation rates similar to known pyridinium oximes used as antidotes in medical practice today. Furthermore, the oximes showed selectivity towards binding to the BChE active site and the determined enzyme-oxime dissociation constants supported work on the future development of inhibitors in other targeted studies (e.g., in treatment of neurodegenerative disease. Also, we monitored the cytotoxic effect of Cinchona oximes on two cell lines Hep G2 and SH-SY5Y to determine the possible limits for in vivo application. The cytotoxicity results support future studies of these compounds as long as their biological activity is targeted in the lower micromolar range.

Transcriptional Inhibition of the Human Papilloma Virus Reactivates Tumor Suppressor p53 in Cervical Carcinoma Cells

Science.gov (United States)

Kochetkov, D. V.; Ilyinskaya, G. V.; Komarov, P. G.; Strom, E.; Agapova, L. S.; Ivanov, A. V.; Budanov, A. V.; Frolova, E. I.; Chumakov, P. M.

2009-01-01

Inactivation of tumor suppressor p53 accompanies the majority of human malignancies. Restoration of p53 function causes death of tumor cells and is potentially suitable for gene therapy of cancer. In cervical carcinoma, human papilloma virus (HPV) E6 facilitates proteasomal degradation of p53. Hence, a possible approach to p53 reactivation is the use of small molecules suppressing the function of viral proteins. HeLa cervical carcinoma cells (HPV-18) with a reporter construct containing the b-galactosidase gene under the control of a p53-responsive promoter were used as a test system to screen a library of small molecules for restoration of the transcriptional activity of p53. The effect of the two most active compounds was studied with cell lines differing in the state of p53-dependent signaling pathways. The compounds each specifically activated p53 in cells expressing HPV-18 and, to a lesser extent, HPV-16 and exerted no effect on control p53-negative cells or cells with the intact p53-dependent pathways. Activation of p53 in cervical carcinoma cells was accompanied by induction of p53-dependent CDKN1 (p21), inhibition of cell proliferation, and induction of apoptosis. In addition, the two compounds dramatically decreased transcription of the HPV genome, which was assumed to cause p53 reactivation. The compounds were low-toxic for normal cells and can be considered as prototypes of new anticancer drugs. PMID:17685229

Vanadium Compounds as PTP Inhibitors

Directory of Open Access Journals (Sweden)

Elsa Irving

2017-12-01

Full Text Available Phosphotyrosine signaling is regulated by the opposing actions of protein tyrosine kinases (PTKs and protein tyrosine phosphatases (PTPs. Here we discuss the potential of vanadium derivatives as PTP enzyme inhibitors and metallotherapeutics. We describe how vanadate in the V oxidized state is thought to inhibit PTPs, thus acting as a pan-inhibitor of this enzyme superfamily. We discuss recent developments in the biological and biochemical actions of more complex vanadium derivatives, including decavanadate and in particular the growing number of oxidovanadium compounds with organic ligands. Pre-clinical studies involving these compounds are discussed in the anti-diabetic and anti-cancer contexts. Although in many cases PTP inhibition has been implicated, it is also clear that many such compounds have further biochemical effects in cells. There also remain concerns surrounding off-target toxicities and long-term use of vanadium compounds in vivo in humans, hindering their progress through clinical trials. Despite these current misgivings, interest in these chemicals continues and many believe they could still have therapeutic potential. If so, we argue that this field would benefit from greater focus on improving the delivery and tissue targeting of vanadium compounds in order to minimize off-target toxicities. This may then harness their full therapeutic potential.

Inhibition of nicotine-DNA adduct formation by polyphenolic compounds in vitro

International Nuclear Information System (INIS)

Cheng Yan; Wang Haifang; Sun Hongfang; Li Hongli

2004-01-01

Nicotine[3-(1-methyl-2-pyrrolidinyl)-pyridine], a major alkaloid in tobacco products, has proven to be a potential genotoxic compound. Some polyphenolic compounds can suppress the DNA adduction, and hence act as the potential inhibitors of carcinogenesis. In this study, the inhibitory effects of three polyphenolic compounds, curcumin (diferuloylmethane), resveratrol (trans-3, 5, 4-trihydroxystilbene) and tea polyphenols, on the nicotine-DNA adduction have been investigated in vitro using radiolabelled nicotine and liquid scintillation counting (LSC) technique. Also, the inhibition mechanism of these chemopreventive agents in regard to the activity of the biotransformation enzymes, including cytochrome P450 (CYP450), cytochrome b 5 (CYb 5 ) and glutathione S-transferase (GST), has been studied. The results demonstrated that these three polyphenols induced marked dose-dependent decrease in nicotine-DNA adducts as compared with the controls. The elimination rate of adducts reached above 46% at the highest dose for all the three agents with 51.6% for resveratrol. Correspondingly, three polyphenols all suppressed CYP450 and CYb 5 , whereas curcumin and resveratrol induced GST. The authors may arrive at a point that the three polyphenols are beneficial to prevent the nicotine adduct formation, and thus may be used to block the potential carcinogenesis induced by nicotine. (authors)

Traditional Japanese medicines inhibit compound action potentials in the frog sciatic nerve.

Science.gov (United States)

Matsushita, Akitomo; Fujita, Tsugumi; Ohtsubo, Sena; Kumamoto, Eiichi

2016-02-03

Traditional Japanese (Kampo) medicines have a variety of clinical effects including pain alleviation, but evidence for a mechanism for their pain relief has not yet been elucidated fully. Considering that Kampo medicine contains many plant-derived chemicals having an ability to inhibit nerve action potential conduction, it is possible that this medicine inhibits nerve conduction. The purpose of the present study was to know how various Kampo medicines affect nerve conduction. We examined the effects of Kampo and crude medicines on compound action potentials (CAPs) recorded from the frog sciatic nerve by using the air-gap method. Daikenchuto, rikkosan, kikyoto, rikkunshito, shakuyakukanzoto and kakkonto concentration-dependently reduced the peak amplitude of the CAP. Among the Kampo medicines, daikenchuto was the most effective in inhibiting CAPs. Daikenchuto is composed of three kinds of crude medicine, Japanese pepper, processed ginger and ginseng radix. When the crude medicines were tested, Japanese pepper and processed ginger reduced CAP peak amplitudes, while ginseng radix hardly affected CAPs. Moreover, there was an interaction between the Japanese pepper and processed ginger activities in such that one medicine at low but not high concentrations increased the extent of the inhibition by the other one that was co-applied. Kampo medicines have an ability to inhibit nerve conduction. This action of daikenchuto is due to Japanese pepper and processed ginger but not ginseng radix, probably through an interaction between Japanese pepper and processed ginger in a manner dependent on their concentrations. Nerve conduction inhibition could contribute to at least a part of Kampo medicine's clinical effects such as pain alleviation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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

of 1.4-49.7 mM. Carbamazepine, gabapentin, primidone, topiramate and vigabatrin showed no inhibition. Additionally, binary drug combinations were tested to investigate if combination therapy could potentiate the aromatase inhibition. Additive inhibition was seen in combination experiments...... with valproate and phenobarbital. When adding carbamazepine to a range of valproate concentrations no additional inhibition was seen. The data for some of the AEDs show that side effects on steroid synthesis in humans due to inhibition of aromatase should be considered....

Review of pulmonary toxicity of indium compounds to animals and humans

International Nuclear Information System (INIS)

Tanaka, Akiyo; Hirata, Miyuki; Kiyohara, Yutaka; Nakano, Makiko; Omae, Kazuyuki; Shiratani, Masaharu; Koga, Kazunori

2010-01-01

Due to the increased production of ITO, the potential health hazards arising from occupational exposure to this material have attracted much attention. This review consists of three parts: 1) toxic effects of indium compounds on animals, 2) toxic effects of indium compounds on humans, and 3) recommendations for preventing exposure to indium compounds in the workplace. Available data have indicated that insoluble form of indium compounds, such as ITO, indium arsenide (InAs) and indium phosphide (InP), can be toxic to animals. Furthermore, InP has demonstrated clear evidence of carcinogenic potential in long-term inhalation studies using experimental animals. As for the dangers to humans, some data are available concerning adverse health effects to workers who have been exposed to indium-containing particles. The Japan Society for Occupational Health recommended the value of 3 μg/L of indium in serum as the occupational exposure limit based on biological monitoring to preventing adverse health effects in workers resulting from occupational exposure to indium compounds. Accordingly, it is essential that much greater attention is focused on human exposure to indium compounds, and precautions against possible exposure to indium compounds are most important with regard to health management among indium-handling workers.

Quercetin inhibits angiogenesis through thrombospondin-1 upregulation to antagonize human prostate cancer PC-3 cell growth in vitro and in vivo.

Science.gov (United States)

Yang, Feiya; Jiang, Xian; Song, Liming; Wang, Huiping; Mei, Zhu; Xu, Zhiqing; Xing, Nianzeng

2016-03-01

The rapid growth, morbidity and mortality of prostate cancer, and the lack of effective treatment have attracted great interests of researchers to find novel cancer therapies aiming to inhibit angiogenesis and tumor growth. Quercetin is a flavonoid compound that widely exists in the nature. Our previous study preliminarily demonstrated that quercetin effectively inhibited human prostate cancer cell xenograft tumor growth by inhibiting angiogenesis. Thrombospondin-1 (TSP-1) is the first reported endogenous anti-angiogenic factor that can inhibit angiogenesis and tumorigenesis. However, the relationship between quercetin inhibiting angiogenesis and TSP-1 upregulation in prostate cancer has not been determined. Thus, we explored the important role of TSP-1 upregulation in reducing angiogenesis and anti-prostate cancer effect of quercetin both in vitro and in vivo for the first time. After the selected doses were used for a certain time, quercetin i) significantly inhibited PC-3 and human umbilical vein endothelial cells (HUVECs) proliferation, migration and invasion in a dose-dependent manner; ⅱ) effectively inhibited prostate cancer PC-3 cell xenograft tumor growth by 37.5% with 75 mg/kg as compared to vehicle control group, more effective than 25 (22.85%) and 50 mg/kg (29.6%); ⅲ) was well tolerated by BALB/c mice and no obvious toxic reactions were observed; ⅳ) greatly reduced angiogenesis and led to higher TSP-1 protein and mRNA expression both in vitro and in vivo in a dose-dependent manner. Therefore, quercetin could increase TSP-1 expression to inhibit angiogenesis resulting in antagonizing prostate cancer PC-3 cell and xenograft tumor growth. The present study can lay a good basis for the subsequent concrete mechanism study and raise the possibility of applying quercetin to clinical for human prostate cancer in the near future.

Inhibition by nucleosides of glucose-transport activity in human erythrocytes.

OpenAIRE

Jarvis, S M

1988-01-01

The interaction of nucleosides with the glucose carrier of human erythrocytes was examined by studying the effect of nucleosides on reversible cytochalasin B-binding activity and glucose transport. Adenosine, inosine and thymidine were more potent inhibitors of cytochalasin B binding to human erythrocyte membranes than was D-glucose [IC50 (concentration causing 50% inhibition) values of 10, 24, 28 and 38 mM respectively]. Moreover, low concentrations of thymidine and adenosine inhibited D-glu...

Luteoloside Inhibits Proliferation of Human Chronic Myeloid ...

African Journals Online (AJOL)

Purpose: To investigate the effects of luteoloside on the proliferation of human chronic ..... Zhang N, Wang D, Zhu Y, Wang J, Lin H. Inhibition ... Han X. Protection of Luteolin-7-O-Glucoside Against ... Hwang YJ, Lee EJ, Kim HR, Hwang KA.

Compound stimulus extinction reduces spontaneous recovery in humans

OpenAIRE

Coelho, Cesar A.O.; Dunsmoor, Joseph E.; Phelps, Elizabeth A.

2015-01-01

Fear-related behaviors are prone to relapse following extinction. We tested in humans a compound extinction design (“deepened extinction”) shown in animal studies to reduce post-extinction fear recovery. Adult subjects underwent fear conditioning to a visual and an auditory conditioned stimulus (CSA and CSB, respectively) separately paired with an electric shock. The target CS (CSA) was extinguished alone followed by compound presentations of the extinguished CSA and nonextinguished CSB. Reco...

Studies to further investigate the inhibition of human liver microsomal CYP2C8 by the acyl-β-glucuronide of gemfibrozil.

Science.gov (United States)

Jenkins, S M; Zvyaga, T; Johnson, S R; Hurley, J; Wagner, A; Burrell, R; Turley, W; Leet, J E; Philip, T; Rodrigues, A D

2011-12-01

In previous studies, gemfibrozil acyl-β-glucuronide, but not gemfibrozil, was found to be a mechanism-based inhibitor of cytochrome P450 2C8. To better understand whether this inhibition is specific for gemfibrozil acyl-β-glucuronide or whether other glucuronide conjugates are potential substrates for inhibition of this enzyme, we evaluated several pharmaceutical compounds (as their acyl glucuronides) as direct-acting and metabolism-dependent inhibitors of CYP2C8 in human liver microsomes. Of 11 compounds that were evaluated as their acyl glucuronide conjugates, only gemfibrozil acyl-β-glucuronide exhibited mechanism-based inhibition, indicating that CYP2C8 mechanism-based inhibition is very specific to certain glucuronide conjugates. Structural analogs of gemfibrozil were synthesized, and their glucuronide conjugates were prepared to further examine the mechanism of inhibition. When the aromatic methyl groups on the gemfibrozil moiety were substituted with trifluoromethyls, the resulting glucuronide conjugate was a weaker inhibitor of CYP2C8 and mechanism-based inhibition was abolished. However, the glucuronide conjugates of monomethyl gemfibrozil analogs were mechanism-based inhibitors of CYP2C8, although not as potent as gemfibrozil acyl-β-glucuronide itself. The ortho-monomethyl analog was a more potent inhibitor than the meta-monomethyl analog, indicating that CYP2C8 favors the ortho position for oxidation and potential inhibition. Molecular modeling of gemfibrozil acyl-β-glucuronide in the CYP2C8 active site is consistent with the ortho-methyl position being the favored site of covalent attachment to the heme. Moreover, hydrogen bonding to four residues (Ser100, Ser103, Gln214, and Asn217) is implicated.

Bovine Lactoferrampin, Human Lactoferricin, and Lactoferrin 1-11 Inhibit Nuclear Translocation of HIV Integrase.

Science.gov (United States)

Wang, Winston Yan; Wong, Jack Ho; Ip, Denis Tsz Ming; Wan, David Chi Cheong; Cheung, Randy Chifai; Ng, Tzi Bun

2016-08-01

This study aimed to investigate fragments derived from human and bovine lactoferrins for ability to inhibit nuclear translocation of HIV-1 integrase. It was shown that human lactoferricin, human lactoferrin 1-11, and bovine lactoferrampin reduced nuclear distribution of HIV-1 integrase. Bovine lactoferrampin could inhibit both the activity and nuclear translocation of HIV-1 integrase. Human lactoferrampin, bovine lactoferricin, and bovine lactoferrin 1-11 had no effect on HIV-1 integrase nuclear translocation. Human lactoferrampin which inhibited the activity of integrase did not prevent its nuclear translocation. Human lactoferricin and lactoferrin 1-11 did not inhibit HIV-1 integrase nuclear translocation despite their ability to attenuate the enzyme activity. The discrepancy between the findings on reduction of HIV-1 activity and inhibition of nuclear translocation of HIV-1 integrase was due to the different mechanisms involved. A similar reasoning can also be applied to the different inhibitory potencies of the milk peptides on different HIV enzymes, i.e., nuclear translocation.

Ellagic acid inhibits the proliferation of human pancreatic carcinoma PANC-1 cells in vitro and in vivo.

Science.gov (United States)

Cheng, Hao; Lu, Chenglin; Tang, Ribo; Pan, Yiming; Bao, Shanhua; Qiu, Yudong; Xie, Min

2017-02-14

Ellagic aicd (EA), a dietary polyphenolic compound found in plants and fruits, possesses various pharmacological activities. This study investigated the effect of EA on human pancreatic carcinoma PANC-1 cells both in vitro and in vivo; and defined the associated molecular mechanisms. In vitro, the cell growth and repairing ability were assessed by CCK-8 assay and wound healing assay. The cell migration and invasion activity was evaluated by Tanswell assay. In vivo, PANC-1 cell tumor-bearing mice were treated with different concentrations of EA. We found that EA significantly inhibited cell growth, cell repairing activity, and cell migration and invasion in a dose-dependent manner. Treatment of PANC-1 xenografted mice with EA resulted in significant inhibition in tumor growth and prolong mice survival rate. Furthermore, flow cytometric analysis showed that EA increased the percentage of cells in the G1 phase of cell cycle. Western blot analysis revealed that EA inhibited the expression of COX-2 and NF-κB. In addition, EA reversed epithelial to mesenchymal transition by up-regulating E-cadherin and down-regulating Vimentin. In summary, the present study demonstrated that EA inhibited cell growth, cell repairing activity, cell migration and invasion in a dose-dependent manner. EA also effectively inhibit human pancreatic cancer growth in mice. The anti-tumor effect of EA might be related to cell cycle arrest, down-regulating the expression of COX-2 and NF-κB, reversing epithelial to mesenchymal transition by up-regulating E-cadherin and down-regulating Vimentin. Our findings suggest that the use of EA would be beneficial for the management of pancreatic cancer.

Inhibition of human immunodeficiency virus replication by a dual CCR5/CXCR4 antagonist

DEFF Research Database (Denmark)

Princen, Katrien; Hatse, Sigrid; Vermeire, Kurt

2004-01-01

Here we report that the N-pyridinylmethyl cyclam analog AMD3451 has antiviral activity against a wide variety of R5, R5/X4, and X4 strains of human immunodeficiency virus type 1 (HIV-1) and HIV-2 (50% inhibitory concentration [IC(50)] ranging from 1.2 to 26.5 microM) in various T-cell lines, CCR5...... at the virus entry stage. AMD3451 dose-dependently inhibited the intracellular Ca(2+) signaling induced by the CXCR4 ligand CXCL12 in T-lymphocytic cells and in CXCR4-transfected cells, as well as the Ca(2+) flux induced by the CCR5 ligands CCL5, CCL3, and CCL4 in CCR5-transfected cells. The compound did...... not interfere with chemokine-induced Ca(2+) signaling through CCR1, CCR2, CCR3, CCR4, CCR6, CCR9, or CXCR3 and did not induce intracellular Ca(2+) signaling by itself at concentrations up to 400 microM. In freshly isolated monocytes, AMD3451 inhibited the Ca(2+) flux induced by CXCL12 and CCL4...

A direct pre-screen for marine bacteria producing compounds inhibiting quorum sensing reveals diverse planktonic bacteria that are bioactive.

Science.gov (United States)

Linthorne, Jamie S; Chang, Barbara J; Flematti, Gavin R; Ghisalberti, Emilio L; Sutton, David C

2015-02-01

A promising new strategy in antibacterial research is inhibition of the bacterial communication system termed quorum sensing. In this study, a novel and rapid pre-screening method was developed to detect the production of chemical inhibitors of this system (quorum-quenching compounds) by bacteria isolated from marine and estuarine waters. This method involves direct screening of mixed populations on an agar plate, facilitating specific isolation of bioactive colonies. The assay showed that between 4 and 46 % of culturable bacteria from various samples were bioactive, and of the 95 selectively isolated bacteria, 93.7 % inhibited Vibrio harveyi bioluminescence without inhibiting growth, indicating potential production of quorum-quenching compounds. Of the active isolates, 21 % showed further activity against quorum-sensing-regulated pigment production by Serratia marcescens. The majority of bioactive isolates were identified by 16S ribosomal DNA (rDNA) amplification and sequencing as belonging to the genera Vibrio and Pseudoalteromonas. Extracts of two strongly bioactive Pseudoalteromonas isolates (K1 and B2) were quantitatively assessed for inhibition of growth and quorum-sensing-regulated processes in V. harveyi, S. marcescens and Chromobacterium violaceum. Extracts of the isolates reduced V. harveyi bioluminescence by as much as 98 % and C. violaceum pigment production by 36 % at concentrations which had no adverse effect on growth. The activity found in the extracts indicated that the isolates may produce quorum-quenching compounds. This study further supports the suggestion that quorum quenching may be a common attribute among culturable planktonic marine and estuarine bacteria.

Inhibition of β-galactosidase and α-glucosidase synthesis in petroleum refinery effluent bacteria by phenolic compounds

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Gideon C. Okpokwasili

2011-04-01

Full Text Available Inhibition of α-glucosidase (EC 3.2.1.20 and β-galactosidase (EC 3.2.1.23 biosynthesis by phenolic compounds (phenol, 2-chlorophenol, 4-chlorophenol, 4-bromophenol and 3,5-dimethylphenol in Escherichia coli, Bacillus and Pseudomonas species isolated from petroleum refinery wastewater was assessed. At sufficient concentrations, phenols inhibited the induction of α-glucosidase and β-galactosidase. The patterns of these toxic effects can be mathematically described with logistic and sigmoid dose-response models. The median inhibitory concentrations (IC50 varied among the phenols, the bacteria and enzymes. Quantitative structure–activity relationship (QSAR models based on the logarithm of the octanol–water partition coefficient (log10Kow were developed for each bacterium. The correlation coefficients varied between 0.84and 0.99 for the enzymes. The test results indicated α-glucosidase and β-galactosidase biosynthesis as important microbial indices for evaluation of toxicity of phenolic compounds.

Inhibition of human placental aromatase activity by hydroxylated polybrominated diphenyl ethers (OH-PBDEs).

Science.gov (United States)

Cantón, Rocío F; Scholten, Deborah E A; Marsh, Göran; de Jong, Paul C; van den Berg, Martin

2008-02-15

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in many different polymers, resins and substrates. Due to their widespread production and use, their high binding affinity to particles, and their lipophilic properties, several PBDE congeners can bioaccumulate in the environment. As a result, PBDEs and their hydroxylated metabolites (OH-PBDEs) have been detected in humans and various wildlife samples, such as birds, seals, and whales. Furthermore, certain OH-PBDEs and their methoxylated derivatives (MeO-PBDEs) are natural products in the marine environment. Recently, our laboratory focused on the possible effects on steroidogenesis of PBDEs and OH-PBDEs, e.g. in the human adrenocortical carcinoma (H295R) cell line indicating that some OH-PBDEs can significantly influence steroidogenic enzymes like CYP19 (aromatase) and CYP17. In the present study, human placental microsomes have been used to study the possible interaction of twenty two OH-PBDEs and MeO-PBDEs with aromatase, the enzyme that mediates the conversion of androgens into estrogens. All OH-PBDE derivates showed significant inhibition of placental aromatase activity with IC(50) values in the low micromolar range, while the MeO-PBDEs did not have any effect on this enzyme activity. Enzyme kinetics studies indicated that two OH-PBDEs, 5-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (5-OH-BDE47) and 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE47), had a mixed-type inhibition of aromatase activity with apparent K(i)/K(i)' of 7.68/0,02 microM and 5.01/0.04 microM respectively. For comparison, some structurally related compounds, a dihydroxylated polybrominated biphenyl, which is a natural product (2,2'-dihyroxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diOH-BB80)) and its non-bromo derivative were also included in the study. Again inhibition of aromatase activity could be measured, but their potency was significantly less than those observed for the OH-PBDEs. These results show that a

Inhibition of human placental aromatase activity by hydroxylated polybrominated diphenyl ethers (OH-PBDEs)

International Nuclear Information System (INIS)

Canton, Rocio F.; Scholten, Deborah E.A.; Marsh, Goeran; Jong, Paul C. de; Berg, Martin van den

2008-01-01

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in many different polymers, resins and substrates. Due to their widespread production and use, their high binding affinity to particles, and their lipophilic properties, several PBDE congeners can bioaccumulate in the environment. As a result, PBDEs and their hydroxylated metabolites (OH-PBDEs) have been detected in humans and various wildlife samples, such as birds, seals, and whales. Furthermore, certain OH-PBDEs and their methoxylated derivatives (MeO-PBDEs) are natural products in the marine environment. Recently, our laboratory focused on the possible effects on steroidogenesis of PBDEs and OH-PBDEs, e.g. in the human adrenocortical carcinoma (H295R) cell line indicating that some OH-PBDEs can significantly influence steroidogenic enzymes like CYP19 (aromatase) and CYP17. In the present study, human placental microsomes have been used to study the possible interaction of twenty two OH-PBDEs and MeO-PBDEs with aromatase, the enzyme that mediates the conversion of androgens into estrogens. All OH-PBDE derivates showed significant inhibition of placental aromatase activity with IC 50 values in the low micromolar range, while the MeO-PBDEs did not have any effect on this enzyme activity. Enzyme kinetics studies indicated that two OH-PBDEs, 5-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (5-OH-BDE47) and 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE47), had a mixed-type inhibition of aromatase activity with apparent K i /K i ' of 7.68/0,02 μM and 5.01/0.04 μM respectively. For comparison, some structurally related compounds, a dihydroxylated polybrominated biphenyl, which is a natural product (2,2'-dihyroxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diOH-BB80)) and its non-bromo derivative were also included in the study. Again inhibition of aromatase activity could be measured, but their potency was significantly less than those observed for the OH-PBDEs. These results show that a wide

Bioactive Compound Content and Cytotoxic Effect on Human Cancer Cells of Fresh and Processed Yellow Tomatoes

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Assunta Raiola

2015-12-01

Full Text Available Tomato, as a fresh or processed product, has a high nutritional value due to its content of bioactive components such as phenolic compounds. Few studies describe the effect of processing on antioxidant content and the cancer cell growth inhibition activity. In this study we determined the phenolic and ascorbic acid content of three yellow tomato varieties, before and after thermal processing. Moreover, we determined the antioxidative power and tested the effects of tomato extracts on three human cancer cell lines. We found that the amount of phenolic acids (chlorogenic acid and caffeic acid decreased in all the samples after processing, whereas the flavonoid content increased after the heat treatment in two samples. A cytotoxic effect of tomato extracts was observed only after processing. This result well correlates with the flavonoid content after processing and clearly indicates that processed yellow tomatoes have a high content of bioactive compounds endowed with cytotoxicity towards cancer cells, thus opening the way to obtain tomato-based functional foods.

Compound K, a metabolite of ginseng saponin, induces apoptosis via caspase-8-dependent pathway in HL-60 human leukemia cells

International Nuclear Information System (INIS)

Cho, Sung-Hee; Chung, Kyung-Sook; Choi, Jung-Hye; Kim, Dong-Hyun; Lee, Kyung-Tae

2009-01-01

Compound K [20-O-β-(D-glucopyranosyl)-20(S)-protopanaxadiol], a metabolite of the protopanaxadiol-type saponins of Panax ginseng C.A. Meyer, has been reported to possess anti-tumor properties to inhibit angiogenesis and to induce tumor apoptosis. In the present study, we investigated the effect of Compound K on apoptosis and explored the underlying mechanisms involved in HL-60 human leukemia cells. We examined the effect of Compound K on the viabilities of various cancer cell lines using MTT assays. DAPI assay, Annexin V and PI double staining, Western blot assay and immunoprecipitation were used to determine the effect of Compound K on the induction of apoptosis. Compound K was found to inhibit the viability of HL-60 cells in a dose- and time-dependent manner with an IC 50 of 14 μM. Moreover, this cell death had typical features of apoptosis, that is, DNA fragmentation, DNA ladder formation, and the externalization of Annexin V targeted phosphatidylserine residues in HL-60 cells. In addition, compound-K induced a series of intracellular events associated with both the mitochondrial- and death receptor-dependent apoptotic pathways, namely, (1) the activation of caspases-3, -8, and -9; (2) the loss of mitochondrial membrane potential; (3) the release of cytochrome c and Smac/DIABLO to the cytosol; (4) the translocation of Bid and Bax to mitochondria; and (5) the downregulations of Bcl-2 and Bcl-xL. Furthermore, a caspase-8 inhibitor completely abolished caspase-3 activation, Bid cleavage, and subsequent DNA fragmentation by Compound K. Interestingly, the activation of caspase-3 and -8 and DNA fragmentation were significantly prevented in the presence of cycloheximide, suggesting that Compound K-induced apoptosis is dependent on de novo protein synthesis. The results indicate that caspase-8 plays a key role in Compound K-stimulated apoptosis via the activation of caspase-3 directly or indirectly through Bid cleavage, cytochrome c release, and caspase-9 activation

Compound K, a metabolite of ginseng saponin, induces apoptosis via caspase-8-dependent pathway in HL-60 human leukemia cells

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Choi Jung-Hye

2009-12-01

Full Text Available Abstract Background Compound K [20-O-β-(D-glucopyranosyl-20(S-protopanaxadiol], a metabolite of the protopanaxadiol-type saponins of Panax ginseng C.A. Meyer, has been reported to possess anti-tumor properties to inhibit angiogenesis and to induce tumor apoptosis. In the present study, we investigated the effect of Compound K on apoptosis and explored the underlying mechanisms involved in HL-60 human leukemia cells. Methods We examined the effect of Compound K on the viabilities of various cancer cell lines using MTT assays. DAPI assay, Annexin V and PI double staining, Western blot assay and immunoprecipitation were used to determine the effect of Compound K on the induction of apoptosis. Results Compound K was found to inhibit the viability of HL-60 cells in a dose- and time-dependent manner with an IC50 of 14 μM. Moreover, this cell death had typical features of apoptosis, that is, DNA fragmentation, DNA ladder formation, and the externalization of Annexin V targeted phosphatidylserine residues in HL-60 cells. In addition, compound-K induced a series of intracellular events associated with both the mitochondrial- and death receptor-dependent apoptotic pathways, namely, (1 the activation of caspases-3, -8, and -9; (2 the loss of mitochondrial membrane potential; (3 the release of cytochrome c and Smac/DIABLO to the cytosol; (4 the translocation of Bid and Bax to mitochondria; and (5 the downregulations of Bcl-2 and Bcl-xL. Furthermore, a caspase-8 inhibitor completely abolished caspase-3 activation, Bid cleavage, and subsequent DNA fragmentation by Compound K. Interestingly, the activation of caspase-3 and -8 and DNA fragmentation were significantly prevented in the presence of cycloheximide, suggesting that Compound K-induced apoptosis is dependent on de novo protein synthesis. Conclusions The results indicate that caspase-8 plays a key role in Compound K-stimulated apoptosis via the activation of caspase-3 directly or indirectly through

Screening of chemical compound libraries identified new anti-Toxoplasma gondii agents.

Science.gov (United States)

Adeyemi, Oluyomi Stephen; Sugi, Tatsuki; Han, Yongmei; Kato, Kentaro

2018-02-01

Toxoplasma gondii is the etiological agent of toxoplasmosis, a common parasitic disease that affects nearly one-third of the human population. The primary infection can be asymptomatic in healthy individuals but may prove fatal in immunocompromised individuals. Available treatment options for toxoplasmosis patients are limited, underscoring the urgent need to identify and develop new therapies. Non-biased screening of libraries of chemical compounds including the repurposing of well-characterized compounds is emerging as viable approach to achieving this goal. In the present investigation, we screened libraries of natural product and FDA-approved compounds to identify those that inhibited T. gondii growth. We identified 32 new compounds that potently inhibit T. gondii growth. Our findings are new and promising, and further strengthen the prospects of drug repurposing as well as the screening of a wide range of chemical compounds as a viable source of alternative anti-parasitic therapeutic agents.

Selective inhibition of CYP2C8 by fisetin and its methylated metabolite, geraldol, in human liver microsomes.

Science.gov (United States)

Shrestha, Riya; Kim, Ju-Hyun; Nam, Wongshik; Lee, Hye Suk; Lee, Jae-Mok; Lee, Sangkyu

2018-04-01

Fisetin is a flavonol compound commonly found in edible vegetables and fruits. It has anti-tumor, antioxidant, and anti-inflammatory effects. Geraldol, the O-methyl metabolite of fisetin in mice, is reported to suppress endothelial cell migration and proliferation. Although the in vivo and in vitro effects of fisetin and its metabolites are frequently reported, studies on herb-drug interactions have not yet been performed. This study was designed to investigate the inhibitory effect of fisetin and geraldol on eight isoforms of human cytochrome P450 (CYP) by using cocktail assay and LC-MS/MS analysis. The selective inhibition of CYP2C8-catalyzed paclitaxel hydroxylation by fisetin and geraldol were confirmed in pooled human liver microsomes (HLMs). In addition, an IC 50 shift assay under different pre-incubation conditions confirmed that fisetin and geraldol shows a reversible concentration-dependent, but not mechanism-based, inhibition of CYP2C8. Moreover, Michaelis-Menten, Lineweaver-burk plots, Dixon and Eadie-Hofstee showed a non-competitive inhibition mode with an equilibrium dissociation constant of 4.1 μM for fisetin and 11.5 μM for geraldol, determined from secondary plot of the Lineweaver-Burk plot. In conclusion, our results indicate that fisetin showed selective reversible and non-competitive inhibition of CYP2C8 more than its main metabolite, geraldol, in HLMs. Copyright © 2018 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

Protein Kinase-A Inhibition Is Sufficient to Support Human Neural Stem Cells Self-Renewal.

Science.gov (United States)

Georges, Pauline; Boissart, Claire; Poulet, Aurélie; Peschanski, Marc; Benchoua, Alexandra

2015-12-01

Human pluripotent stem cell-derived neural stem cells offer unprecedented opportunities for producing specific types of neurons for several biomedical applications. However, to achieve it, protocols of production and amplification of human neural stem cells need to be standardized, cost effective, and safe. This means that small molecules should progressively replace the use of media containing cocktails of protein-based growth factors. Here we have conducted a phenotypical screening to identify pathways involved in the regulation of hNSC self-renewal. We analyzed 80 small molecules acting as kinase inhibitors and identified compounds of the 5-isoquinolinesulfonamide family, described as protein kinase A (PKA) and protein kinase G inhibitors, as candidates to support hNSC self-renewal. Investigating the mode of action of these compounds, we found that modulation of PKA activity was central in controlling the choice between self-renewal or terminal neuronal differentiation of hNSC. We finally demonstrated that the pharmacological inhibition of PKA using the small molecule HA1004 was sufficient to support the full derivation, propagation, and long-term maintenance of stable hNSC in absence of any other extrinsic signals. Our results indicated that tuning of PKA activity is a core mechanism regulating hNSC self-renewal and differentiation and delineate the minimal culture media requirement to maintain undifferentiated hNSC in vitro. © 2015 AlphaMed Press.

Arctigenin, a natural lignan compound, induces G0/G1 cell cycle arrest and apoptosis in human glioma cells

OpenAIRE

Maimaitili, Aisha; Shu, Zunhua; Cheng, Xiaojiang; Kaheerman, Kadeer; Sikandeer, Alifu; Li, Weimin

2016-01-01

The aim of the current study was to investigate the anticancer potential of arctigenin, a natural lignan compound, in malignant gliomas. The U87MG and T98G human glioma cell lines were treated with various concentrations of arctigenin for 48 h and the effects of arctigenin on the aggressive phenotypes of glioma cells were assessed. The results demonstrated that arctigenin dose-dependently inhibited the growth of U87MG and T98G cells, as determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphen...

Molecular modeling reveals the novel inhibition mechanism and binding mode of three natural compounds to staphylococcal α-hemolysin.

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Jiazhang Qiu

Full Text Available α-Hemolysin (α-HL is a self-assembling, channel-forming toxin that is produced as a soluble monomer by Staphylococcus aureus strains. Until now, α-HL has been a significant virulence target for the treatment of S. aureus infection. In our previous report, we demonstrated that some natural compounds could bind to α-HL. Due to the binding of those compounds, the conformational transition of α-HL from the monomer to the oligomer was blocked, which resulted in inhibition of the hemolytic activity of α-HL. However, these results have not indicated how the binding of the α-HL inhibitors influence the conformational transition of the whole protein during the oligomerization process. In this study, we found that three natural compounds, Oroxylin A 7-O-glucuronide (OLG, Oroxin A (ORA, and Oroxin B (ORB, when inhibiting the hemolytic activity of α-HL, could bind to the "stem" region of α-HL. This was completed using conventional Molecular Dynamics (MD simulations. By interacting with the novel binding sites of α-HL, the ligands could form strong interactions with both sides of the binding cavity. The results of the principal component analysis (PCA indicated that because of the inhibitors that bind to the "stem" region of α-HL, the conformational transition of α-HL from the monomer to the oligomer was restricted. This caused the inhibition of the hemolytic activity of α-HL. This novel inhibition mechanism has been confirmed by both the steered MD simulations and the experimental data obtained from a deoxycholate-induced oligomerization assay. This study can facilitate the design of new antibacterial drugs against S. aureus.

Antimycobacterial and Photosynthetic Electron Transport Inhibiting Activity of Ring-Substituted 4-Arylamino-7-Chloroquinolinium Chlorides

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Alois Cizek

2013-09-01

Full Text Available In this study, a series of twenty-five ring-substituted 4-arylamino-7-chloroquinolinium chlorides were prepared and characterized. The compounds were tested for their activity related to inhibition of photosynthetic electron transport (PET in spinach (Spinacia oleracea L. chloroplasts and also primary in vitro screening of the synthesized compounds was performed against mycobacterial species. 4-[(2-Bromophenylamino]-7-chloroquinolinium chloride showed high biological activity against M. marinum, M. kansasii, M. smegmatis and 7-chloro-4-[(2-methylphenylamino]quinolinium chloride demonstrated noteworthy biological activity against M. smegmatis and M. avium subsp. paratuberculosis. The most effective compounds demonstrated quite low toxicity (LD50 > 20 μmol/L against the human monocytic leukemia THP-1 cell line within preliminary in vitro cytotoxicity screening. The tested compounds were found to inhibit PET in photosystem II. The PET-inhibiting activity expressed by IC50 value of the most active compound 7-chloro-4-[(3-trifluoromethylphenylamino]quinolinium chloride was 27 μmol/L and PET-inhibiting activity of ortho-substituted compounds was significantly lower than this of meta- and para-substituted ones. The structure-activity relationships are discussed for all compounds.

Wild Bitter Melon Leaf Extract Inhibits Porphyromonas gingivalis-Induced Inflammation: Identification of Active Compounds through Bioassay-Guided Isolation

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Tzung-Hsun Tsai

2016-04-01

Full Text Available Porphyromonas gingivalis has been identified as one of the major periodontal pathogens. Activity-directed fractionation and purification processes were employed to identify the anti-inflammatory active compounds using heat-killed P. gingivalis-stimulated human monocytic THP-1 cells in vitro. Five major fractions were collected from the ethanol/ethyl acetate extract of wild bitter melon (Momordica charantia Linn. var. abbreviata Ser. leaves and evaluated for their anti-inflammatory activity against P. gingivalis. Among the test fractions, Fraction 5 effectively decreased heat-killed P. gingivalis-induced interleukin (IL-8 and was subjected to separation and purification by using chromatographic techniques. Two cucurbitane triterpenoids were isolated from the active fraction and identified as 5β,19-epoxycucurbita-6,23-diene-3β,19,25-triol (1 and 3β,7β,25-trihydroxycucurbita-5,23-dien-19-al (2 by comparing spectral data. Treatments of both compounds in vitro potently suppressed P. gingivalis-induced IL-8, IL-6, and IL-1β levels and the activation of mitogen-activated protein kinase (MAPK in THP-1 cells. Both compounds effectively inhibited the mRNA levels of IL-6, tumor necrosis factor (TNF-α, and cyclooxygenase (COX-2 in P. gingivalis-stimulated gingival tissue of mice. These findings imply that 5β,19-epoxycucurbita-6,23-diene-3β,19,25-triol and 3β,7β,25-trihydroxycucurbita-5,23-dien-19-al could be used for the development of novel therapeutic approaches against P. gingivalis infections.

Inhibition of phospholipase A2 from human plasma by sodium bisulfite

International Nuclear Information System (INIS)

Wiggins, C.W.; Franson, R.C.

1987-01-01

The anti-oxidant sodium bisulfite has been shown to inhibit acid active(lysosomal), non-Ca ++ -dependent phospholipase A 2 (PLA 2 ), and to interact reversibly with unsaturated fatty acids, altering their chromatographic mobility. The authors examined the effect of bisulfite on neutral active, Ca ++ -dependent PLA 2 from human plasma. Using [1- 14 C]oleate-labelled autoclaved E. coli as substrate, PLA 2 activity was inhibited in a dose-dependent manner by bisulfite. Maximal inhibition occurred at 100μM bisulfite. Preincubation of plasma for 0-30 minutes with bisulfite resulted in a time-dependent increase in PLA 2 inhibition. Preincubation of substrate with bisulfite had no such effect. When the plasma PLA 2 was purified 25-fold by SP-Sephadex chromatography it was no longer inhibited by bisulfite. The SP-Sephadex wash through fraction, which contained greater than 95% of the applied protein but not PLA 2 activity, did not inhibit the purified enzyme. When incubated with bisulfite however, the SP-wash through fraction produced dose-dependent inhibition of the purified enzyme. These results indicate that sodium bisulfite inhibits human plasma PLA 2 , in vitro, indirectly by interaction with a factor(s) present in plasma and suggests that anti-oxidants may similarly influence expression of extracellular PLA 2 in vivo

The inhibition of the Human Immunodeficiency Virus type 1 activity by crude and purified human pregnancy plug mucus and mucins in an inhibition assay

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Schoeman Leann

2008-05-01

Full Text Available Abstract Background The female reproductive tract is amongst the main routes for Human Immunodeficiency Virus (HIV transmission. Cervical mucus however is known to protect the female reproductive tract from bacterial invasion and fluid loss and regulates and facilitates sperm transport to the upper reproductive tract. The purpose of this study was to purify and characterize pregnancy plug mucins and determine their anti-HIV-1 activity in an HIV inhibition assay. Methods Pregnancy plug mucins were purified by caesium chloride density-gradient ultra-centrifugation and characterized by Western blotting analysis. The anti-HIV-1 activities of the crude pregnancy plug mucus and purified pregnancy plug mucins was determined by incubating them with HIV-1 prior to infection of the human T lymphoblastoid cell line (CEM SS cells. Results The pregnancy plug mucus had MUC1, MUC2, MUC5AC and MUC5B. The HIV inhibition assay revealed that while the purified pregnancy plug mucins inhibit HIV-1 activity by approximately 97.5%, the crude pregnancy plug mucus failed to inhibit HIV-1 activity. Conclusion Although it is not clear why the crude sample did not inhibit HIV-1 activity, it may be that the amount of mucins in the crude pregnancy plug mucus (which contains water, mucins, lipids, nucleic acids, lactoferrin, lysozyme, immunoglobulins and ions, is insufficient to cause viral inhibition or aggregation.

Two natural products, trans-phytol and (22E)-ergosta-6,9,22-triene-3β,5α,8α-triol, inhibit the biosynthesis of estrogen in human ovarian granulosa cells by aromatase (CYP19)

Energy Technology Data Exchange (ETDEWEB)

Guo, Jiajia [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Yuan, Yun [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang (China); Lu, Danfeng; Du, Baowen [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Xiong, Liang; Shi, Jiangong [State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Yang, Lijuan [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Liu, Wanli [MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084 (China); Yuan, Xiaohong [School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang (China); Zhang, Guolin, E-mail: zhanggl@cib.ac.cn [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu (China); Wang, Fei, E-mail: wangfei@cib.ac.cn [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu (China)

2014-08-15

Aromatase is the only enzyme in vertebrates to catalyze the biosynthesis of estrogens. Although inhibitors of aromatase have been developed for the treatment of estrogen-dependent breast cancer, the whole-body inhibition of aromatase causes severe adverse effects. Thus, tissue-selective aromatase inhibitors are important for the treatment of estrogen-dependent cancers. In this study, 63 natural products with diverse structures were examined for their effects on estrogen biosynthesis in human ovarian granulosa-like KGN cells. Two compounds—trans-phytol (SA-20) and (22E)-ergosta-6,9,22-triene-3β,5α,8α-triol (SA-48)—were found to potently inhibit estrogen biosynthesis (IC{sub 50}: 1 μM and 0.5 μM, respectively). Both compounds decreased aromatase mRNA and protein expression levels in KGN cells, but had no effect on the aromatase catalytic activity in aromatase-overexpressing HEK293A cells and recombinant expressed aromatase. The two compounds decreased the expression of aromatase promoter I.3/II. Neither compound affected intracellular cyclic AMP (cAMP) levels, but they inhibited the phosphorylation or protein expression of cAMP response element-binding protein (CREB). The effects of these two compounds on extracellular regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinases (MAPKs), and AKT/phosphoinositide 3-kinase (PI3K) pathway were examined. Inhibition of p38 MAPK could be the mechanism underpinning the actions of these compounds. Our results suggests that natural products structurally similar to SA-20 and SA-48 may be a new source of tissue-selective aromatase modulators, and that p38 MAPK is important in the basal control of aromatase in ovarian granulosa cells. SA-20 and SA-48 warrant further investigation as new pharmaceutical tools for the prevention and treatment of estrogen-dependent cancers. - Highlights: • Two natural products inhibited estrogen biosynthesis in human ovarian granulosa cells. • They

A Common Mechanism for Resistance to Oxime Reactivation of Acetylcholinesterase Inhibited by Organophosphorus Compounds

Science.gov (United States)

2013-01-01

reactivated than AChE conjugates inhibited by the corresponding Rp enantiomers and this effect is enhanced as the size of the O-alkyl substituents of OP...Organophosphates and Carbamates, Butterworth & Heinemann , Oxford, 1992. pp. 555–577. [2] P. Taylor, Anticholinesterase agents, in: L.L. Brunton, J.S...application of the Hammett equation with the constants rph in the chemistry of organophosphorus compounds, Russ. Chem. Rev. 38 (1969) 795–811. [13

ITE inhibits growth of human pulmonary artery endothelial cells.

Science.gov (United States)

Pang, Ling-Pin; Li, Yan; Zou, Qing-Yun; Zhou, Chi; Lei, Wei; Zheng, Jing; Huang, Shi-An

2017-10-01

Pulmonary arterial hypertension (PAH), a deadly disorder is associated with excessive growth of human pulmonary artery endothelial (HPAECs) and smooth muscle (HPASMCs) cells. Current therapies primarily aim at promoting vasodilation, which only ameliorates clinical symptoms without a cure. 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) is an endogenous aryl hydrocarbon receptor (AhR) ligand, and mediates many cellular function including cell growth. However, the roles of ITE in human lung endothelial cells remain elusive. Herein, we tested a hypothesis that ITE inhibits growth of human pulmonary artery endothelial cells via AhR. Immunohistochemistry was performed to localize AhR expression in human lung tissues. The crystal violet method and MTT assay were used to determine ITE's effects on growth of HPAECs. The AhR activation in HPAECs was confirmed using Western blotting and RT-qPCR. The role of AhR in ITE-affected proliferation of HPAECs was assessed using siRNA knockdown method followed by the crystal violet method. Immunohistochemistry revealed that AhR was present in human lung tissues, primarily in endothelial and smooth muscle cells of pulmonary veins and arteries, as well as in bronchial and alveolar sac epithelia. We also found that ITE dose- and time-dependently inhibited proliferation of HPAECs with a maximum inhibition of 83% at 20 µM after 6 days of treatment. ITE rapidly decreased AhR protein levels, while it increased mRNA levels of cytochrome P450 (CYP), family 1, member A1 (CYP1A1) and B1 (CYP1B1), indicating activation of the AhR/CYP1A1 and AhR/CYP1B1 pathways in HPAECs. The AhR siRNA significantly suppressed AhR protein expression, whereas it did not significantly alter ITE-inhibited growth of HPAECs. ITE suppresses growth of HPAECs independent of AhR, suggesting that ITE may play an important role in preventing excessive growth of lung endothelial cells.

Isorhapontigenin (ISO) Inhibits Invasive Bladder Cancer Formation In Vivo and Human Bladder Cancer Invasion In Vitro by Targeting STAT1/FOXO1 Axis.

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Jiang, Guosong; Wu, Amy D; Huang, Chao; Gu, Jiayan; Zhang, Liping; Huang, Haishan; Liao, Xin; Li, Jingxia; Zhang, Dongyun; Zeng, Xingruo; Jin, Honglei; Huang, Haojie; Huang, Chuanshu

2016-07-01

Although our most recent studies have identified Isorhapontigenin (ISO), a novel derivative of stilbene that isolated from a Chinese herb Gnetum cleistostachyum, for its inhibition of human bladder cancer growth, nothing is known whether ISO possesses an inhibitory effect on bladder cancer invasion. Thus, we addressed this important question in current study and discovered that ISO treatment could inhibit mouse-invasive bladder cancer development following bladder carcinogen N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) exposure in vivo We also found that ISO suppressed human bladder cancer cell invasion accompanied by upregulation of the forkhead box class O 1 (FOXO1) mRNA transcription in vitro Accordingly, FOXO1 was profoundly downregulated in human bladder cancer tissues and was negatively correlated with bladder cancer invasion. Forced expression of FOXO1 specifically suppressed high-grade human bladder cancer cell invasion, whereas knockdown of FOXO1 promoted noninvasive bladder cancer cells becoming invasive bladder cancer cells. Moreover, knockout of FOXO1 significantly increased bladder cancer cell invasion and abolished the ISO inhibition of invasion in human bladder cancer cells. Further studies showed that the inhibition of Signal transducer and activator of transcription 1 (STAT1) phosphorylation at Tyr701 was crucial for ISO upregulation of FOXO1 transcription. Furthermore, this study revealed that metalloproteinase-2 (MMP-2) was a FOXO1 downstream effector, which was also supported by data obtained from mouse model of ISO inhibition BBN-induced mouse-invasive bladder cancer formation. These findings not only provide a novel insight into the understanding of mechanism of bladder cancer's propensity to invasion, but also identify a new role and mechanisms underlying the natural compound ISO that specifically suppresses such bladder cancer invasion through targeting the STAT1-FOXO1-MMP-2 axis. Cancer Prev Res; 9(7); 567-80. ©2016 AACR. ©2016 American

Inhibition of Pseudogymnoascus destructans growth from conidia and mycelial extension by bacterially produced volatile organic compounds.

Science.gov (United States)

Cornelison, Christopher T; Gabriel, Kyle T; Barlament, Courtney; Crow, Sidney A

2014-02-01

The recently identified causative agent of white-nose syndrome (WNS), Pseudogymnoascus destructans, has been implicated in the mortality of an estimated 5.5 million North American bats since its initial documentation in 2006 (Frick et al. in Science 329:679-682, 2010). In an effort to identify potential biological and chemical control options for WNS, 6 previously described bacterially produced volatile organic compounds (VOCs) were screened for anti-P. destructans activity. The compounds include decanal; 2-ethyl-1-hexanol; nonanal; benzothiazole; benzaldehyde; andN,N-dimethyloctylamine. P. destructans conidia and mycelial plugs were exposed to the VOCs in a closed air space at 15 and 4 °C and then evaluated for growth inhibition. All VOCs inhibited growth from conidia as well as inhibiting radial mycelial extension, with the greatest effect at 4 °C. Studies of the ecology of fungistatic soils and the natural abundance of the fungistatic VOCs present in these environments suggest a synergistic activity of select VOCs may occur. The evaluation of formulations of two or three VOCs at equivalent concentrations was supportive of synergistic activity in several cases. The identification of bacterially produced VOCs with anti-P. destructans activity indicates disease-suppressive and fungistatic soils as a potentially significant reservoir of biological and chemical control options for WNS and provides wildlife management personnel with tools to combat this devastating disease.

Aldose reductase inhibitory compounds from Xanthium strumarium.

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Yoon, Ha Na; Lee, Min Young; Kim, Jin-Kyu; Suh, Hong-Won; Lim, Soon Sung

2013-09-01

As part of our ongoing search for natural sources of therapeutic and preventive agents for diabetic complications, we evaluated the inhibitory effects of components of the fruit of Xanthium strumarium (X. strumarium) on aldose reductase (AR) and galactitol formation in rat lenses with high levels of glucose. To identify the bioactive components of X. strumarium, 7 caffeoylquinic acids and 3 phenolic compounds were isolated and their chemical structures were elucidated on the basis of spectroscopic evidence and comparison with published data. The abilities of 10 X. strumarium-derived components to counteract diabetic complications were investigated by means of inhibitory assays with rat lens AR (rAR) and recombinant human AR (rhAR). From the 10 isolated compounds, methyl-3,5-di-O-caffeoylquinate showed the most potent inhibition, with IC₅₀ values of 0.30 and 0.67 μM for rAR and rhAR, respectively. In the kinetic analyses using Lineweaver-Burk plots of 1/velocity and 1/substrate, methyl-3,5-di-O-caffeoylquinate showed competitive inhibition of rhAR. Furthermore, methyl-3,5-di-O-caffeoylquinate inhibited galactitol formation in the rat lens and in erythrocytes incubated with a high concentration of glucose, indicating that this compound may be effective in preventing diabetic complications.

Physiological markers of motor inhibition during human behavior

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Duque, Julie; Greenhouse, Ian; Labruna, Ludovica; Ivry, Richard B.

2017-01-01

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. PMID:28341235

Vitamin D compounds inhibit cancer stem-like cells and induce differentiation in triple negative breast cancer.

Science.gov (United States)

Shan, Naing Lin; Wahler, Joseph; Lee, Hong Jin; Bak, Min Ji; Gupta, Soumyasri Das; Maehr, Hubert; Suh, Nanjoo

2017-10-01

Triple-negative breast cancer is one of the least responsive breast cancer subtypes to available targeted therapies due to the absence of hormonal receptors, aggressive phenotypes, and the high rate of relapse. Early breast cancer prevention may therefore play an important role in delaying the progression of triple-negative breast cancer. Cancer stem cells are a subset of cancer cells that are thought to be responsible for tumor progression, treatment resistance, and metastasis. We have previously shown that vitamin D compounds, including a Gemini vitamin D analog BXL0124, suppress progression of ductal carcinoma in situ in vivo and inhibit cancer stem-like cells in MCF10DCIS mammosphere cultures. In the present study, the effects of vitamin D compounds in regulating breast cancer stem-like cells and differentiation in triple-negative breast cancer were assessed. Mammosphere cultures, which enriches for breast cancer cells with stem-like properties, were used to assess the effects of 1α,25(OH) 2 D 3 and BXL0124 on cancer stem cell markers in the triple-negative breast cancer cell line, SUM159. Vitamin D compounds significantly reduced the mammosphere forming efficiency in primary, secondary and tertiary passages of mammospheres compared to control groups. Key markers of cancer stem-like phenotype and pluripotency were analyzed in mammospheres treated with 1α,25(OH) 2 D 3 and BXL0124. As a result, OCT4, CD44 and LAMA5 levels were decreased. The vitamin D compounds also down-regulated the Notch signaling molecules, Notch1, Notch2, Notch3, JAG1, JAG2, HES1 and NFκB, which are involved in breast cancer stem cell maintenance. In addition, the vitamin D compounds up-regulated myoepithelial differentiating markers, cytokeratin 14 and smooth muscle actin, and down-regulated the luminal marker, cytokeratin 18. Cytokeratin 5, a biomarker associated with basal-like breast cancer, was found to be significantly down-regulated by the vitamin D compounds. These results suggest

Inhibition of cholinesterase activity by extracts, fractions and compounds from Calceolaria talcana and C. integrifolia (Calceolariaceae: Scrophulariaceae).

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Cespedes, Carlos L; Muñoz, Evelyn; Salazar, Juan R; Yamaguchi, Lydia; Werner, Enrique; Alarcon, Julio; Kubo, Isao

2013-12-01

Extracts, fractions and compounds from Calceolaria talcana and C. integrifolia exhibited strong inhibitory effects of the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes using the in vitro Ellman's method. The most active samples were from the ethyl acetate extract, which caused a mixed-type inhibition against AChE (69.8% and 79.5% at 100 and 200 μg/ml, respectively) and against BChE (98.5% and 99.8% at 100 and 200 μg/ml, respectively) and its major components verbascoside 8 (50.9% and 70.0% at 200 μg/ml, against AChE and BChE, respectively), martynoside 9, and fraction F-7 (which corresponds to a mixture of 8, 9, and other phenylethanoids and phenolics that remain unidentified) (80.2% and 85.3% at 100 and 200 μg/ml, against AChE, respectively and 99.1% and 99.7% at 100 and 200 μg/ml, against BChE, respectively) inhibited the acetylcholinesterase enzyme competitively. The most polar fraction F-5 from n-hexane extract (a mixture of naphthoquinones: 2-hydroxy-3-(1,1-dimethylallyl-1,4-naphthoquinone) 6, α-dunnione 7 and other polar compounds that remain unidentified) showed a mixed-type inhibition (71.5% and 72.1% against AChE and BChE at 200 μg/ml, respectively). Finally, the methanol-soluble residue presented a complex, mixed-type inhibition (39.9% and 67.9% against AChE and BChE at 200 μg/ml, respectively). The mixture F-3 with diterpenes was obtained from the n-hexane extract: (1,10-cyclopropyl-9-epi-ent-isopimarol) 1, 19-α-hydroxy-abietatriene 2, and F-4 a mixture of triterpenes α-lupeol 3, β-sitosterol 4, ursolic acid 5 together with a complex mixture of terpenes that did not show activity. In summary, extracts and natural compounds from C. talcana and C. integrifolia were isolated, identified and characterized as cholinesterase inhibitors.

H32, a non-quinone sulfone analog of vitamin K3, inhibits human hepatoma cell growth by inhibiting Cdc25 and activating ERK.

Science.gov (United States)

Kar, Siddhartha; Wang, Meifang; Ham, Seung Wook; Carr, Brian I

2006-10-01

We previously synthesized a K-vitamin derivative, Cpd 5, which was a potent growth inhibitor of human tumor cells, including Hep3B hepatoma cells. However, being a quinone compound, Cpd 5 has the potential for generating toxic reactive oxygen species (ROS). We therefore synthesized a nonquinone sulfone derivative, H32, which has a sufone group substituting the quinone. The IC50 of H32 for Hep3B cells was found to be 2.5 microM, which was 2.5 and 3.2 times more potent than Cpd 5 and vitamin K3 respectively. It induced apoptosis in Hep3B cells but did not generate ROS when compared to Cpd 5. Interestingly, under similar culture conditions, normal rat hepatocytes were 14-fold more and 7-fold more resistant to the growth inhibitory effects of H32 than Hep3B and PLC/PRF5 cells respectively. H32 preferentially inhibited the activities of the cell cycle controlling Cdc25A phosphatase likely by binding to its catalytic cysteine. As a consequence, it induced inhibitory tyrosine phosphorylation of the Cdc25 substrate kinases Cdk2 and Cdk4 in Hep3B cells and the cells undergo an arrest in the G1 phase of the cell cycle. H32 also induced persistent phosphorylation of the MAPK protein ERK1/2, but marginal JNK1/2 and p38 phosphorylation. The ERK inhibitor U0126, added at least 30 min prior to H32, antagonized the growth inhibition induced by H32. However, the JNK and p38 inhibitors, JNKI-II and SB203580, were not able to antagonize H32 induced growth inhibition. Thus, H32 differentially inhibited growth of normal and liver tumor cells by preferentially inhibiting the actions of Cdc25 phosphatases and inducing persistent ERK phosphorylation.

Comparison of oxime reactivation and aging of nerve agent-inhibited monkey and human acetylcholinesterases.

Science.gov (United States)

Luo, Chunyuan; Tong, Min; Maxwell, Donald M; Saxena, Ashima

2008-09-25

Non-human primates are valuable animal models that are used for the evaluation of nerve agent toxicity as well as antidotes and results from animal experiments are extrapolated to humans. It has been demonstrated that the efficacy of an oxime primarily depends on its ability to reactivate nerve agent-inhibited acetylcholinesterase (AChE). If the in vitro oxime reactivation of nerve agent-inhibited animal AChE is similar to that of human AChE, it is likely that the results of an in vivo animal study will reliably extrapolate to humans. Therefore, the goal of this study was to compare the aging and reactivation of human and different monkey (Rhesus, Cynomolgus, and African Green) AChEs inhibited by GF, GD, and VR. The oximes examined include the traditional oxime 2-PAM, two H-oximes HI-6 and HLo-7, and the new candidate oxime MMB4. Results indicate that oxime reactivation of all three monkey AChEs was very similar to human AChE. The maximum difference in the second-order reactivation rate constant between human and three monkey AChEs or between AChEs from different monkey species was 5-fold. Aging rate constants of GF-, GD-, and VR-inhibited monkey AChEs were very similar to human AChE except for GF-inhibited monkey AChEs, which aged 2-3 times faster than the human enzyme. The results of this study suggest that all three monkey species are suitable animal models for nerve agent antidote evaluation since monkey AChEs possess similar biochemical/pharmacological properties to human AChE.

Eugenol and its synthetic analogues inhibit cell growth of human cancer cells (Part I)

International Nuclear Information System (INIS)

Carrasco A, H.; Cardona, W.; Espinoza C, L.; Gallardo, C.; Catalan M, K.; Cardile, V.; Lombardo, L.; Cuellar F, M.; Russo, A.

2008-01-01

Eugenol (4-allyl-2-methoxyphenol) (1) has been reported to possess antioxidant and anticancer properties. In an attempt to enhance intrinsic activity of this natural compound, some derivatives were synthesized. Eugenol was extracted from cloves oil and further, the eugenol analogues (2-6) were obtained through acetylation and nitration reactions. Eugenol (1) and its analogues (2-6) were examined by in vitro model of cancer using two human cancer cell lines: DU-145 (androgeninsensitive prostate cancer cells) and KB (oral squamous carcinoma cells). Cell viability, by tetrazolium salts assay, was measured. Lactic dehydrogenase (LDH) release was also investigated to evaluate the presence of cell toxicity as a result of cell disruption, subsequent to membrane rupture. In the examined cancer cells, all compounds showed cell-growth inhibition activity. The obtained results demonstrate that the compounds 5-allyl-3-nitrobenzene-1,2-diol (3) and 4-allyl- 2-methoxy-5-nitrophenyl acetate (5) were significantly (p 50 values in DU-145 cells of 19.02 x 10 -6 and 21.5 x 10 -6 mol L -1 , respectively, and in KB cells of 18.11 x 10 -6 and 21.26 x 10 -6 mol L -1 , respectively, suggesting that the presence of nitro and hydroxyl groups could be important in the activity of these compounds. In addition, our results seem to indicate that apoptotic cell demise appears to be induced in KB and DU-145 cells. In fact, in our experimental conditions, no statistically significant increase in LDH release was observed in cancer cells treated with eugenol and its analogues. (author)

Derivatives of amphotericin inhibit infection with human immunodeficiency virus in vitro by different modes of action

DEFF Research Database (Denmark)

Hansen, J E; Witzke, N M; Nielsen, C

1990-01-01

Three water-soluble derivatives of amphotericin B were tested for inhibition of HIV infection in vitro. The compounds amphotericin B methyl ester (AME) and N-(N'-(2-(4'-methylmorpholinio)ethyl)N"-cyclohexyl guanyl) amphotericin B methyl ester (MCG) inhibited HIV infection by 50% at 1 microgram/ml...

Recombinant human prion protein inhibits prion propagation in vitro.

Science.gov (United States)

Yuan, Jue; Zhan, Yi-An; Abskharon, Romany; Xiao, Xiangzhu; Martinez, Manuel Camacho; Zhou, Xiaochen; Kneale, Geoff; Mikol, Jacqueline; Lehmann, Sylvain; Surewicz, Witold K; Castilla, Joaquín; Steyaert, Jan; Zhang, Shulin; Kong, Qingzhong; Petersen, Robert B; Wohlkonig, Alexandre; Zou, Wen-Quan

2013-10-09

Prion diseases are associated with the conformational conversion of the cellular prion protein (PrP(C)) into the pathological scrapie isoform (PrP(Sc)) in the brain. Both the in vivo and in vitro conversion of PrP(C) into PrP(Sc) is significantly inhibited by differences in amino acid sequence between the two molecules. Using protein misfolding cyclic amplification (PMCA), we now report that the recombinant full-length human PrP (rHuPrP23-231) (that is unglycosylated and lacks the glycophosphatidylinositol anchor) is a strong inhibitor of human prion propagation. Furthermore, rHuPrP23-231 also inhibits mouse prion propagation in a scrapie-infected mouse cell line. Notably, it binds to PrP(Sc), but not PrP(C), suggesting that the inhibitory effect of recombinant PrP results from blocking the interaction of brain PrP(C) with PrP(Sc). Our findings suggest a new avenue for treating prion diseases, in which a patient's own unglycosylated and anchorless PrP is used to inhibit PrP(Sc) propagation without inducing immune response side effects.

Mechanism of inhibition of myeloperoxidase by anti-inflammatory drugs.

Science.gov (United States)

Kettle, A J; Winterbourn, C C

1991-05-15

Hypochlorous acid (HOCl) is the most powerful oxidant produced by human neutrophils, and should therefore be expected to contribute to the damage caused by these inflammatory cells. It is produced from H2O2 and Cl- by the heme enzyme myeloperoxidase (MPO). We used a H2O2-electrode to assess the ability of a variety of anti-inflammatory drugs to inhibit conversion of H2O2 to HOCl. Dapsone, mefenamic acid, sulfapyridine, quinacrine, primaquine and aminopyrine were potent inhibitors, giving 50% inhibition of the initial rate of H2O2 loss at concentrations of about 1 microM or less. Phenylbutazone, piroxicam, salicylate, olsalazine and sulfasalazine were also effective inhibitors. Spectral investigations showed that the inhibitors acted by promoting the formation of compound II, which is an inactive redox intermediate of MPO. Ascorbate reversed inhibition by reducing compound II back to the active enzyme. The characteristic properties that allowed the drugs to inhibit MPO reversibly were ascertained by determining the inhibitory capacity of related phenols and anilines. Inhibition increased as substituents on the aromatic ring became more electron withdrawing, until an optimum reduction potential was reached. Beyond this optimum, their inhibitory capacity declined. The best inhibitor was 4-bromoaniline which had an I50 of 45 nM. An optimum reduction potential enables inhibitors to reduce MPO to compound II, but prevents them from reducing compound II back to the active enzyme. Exploitation of this optimum reduction potential will help in targeting drugs against HOCl-dependent tissue damage.

Antioxidative Dietary Compounds Modulate Gene Expression Associated with Apoptosis, DNA Repair, Inhibition of Cell Proliferation and Migration

Directory of Open Access Journals (Sweden)

Likui Wang

2014-09-01

Full Text Available Many dietary compounds are known to have health benefits owing to their antioxidative and anti-inflammatory properties. To determine the molecular mechanism of these food-derived compounds, we analyzed their effect on various genes related to cell apoptosis, DNA damage and repair, oxidation and inflammation using in vitro cell culture assays. This review further tests the hypothesis proposed previously that downstream products of COX-2 (cyclooxygenase-2 called electrophilic oxo-derivatives induce antioxidant responsive elements (ARE, which leads to cell proliferation under antioxidative conditions. Our findings support this hypothesis and show that cell proliferation was inhibited when COX-2 was down-regulated by polyphenols and polysaccharides. Flattened macrophage morphology was also observed following the induction of cytokine production by polysaccharides extracted from viili, a traditional Nordic fermented dairy product. Coix lacryma-jobi (coix polysaccharides were found to reduce mitochondrial membrane potential and induce caspase-3- and 9-mediated apoptosis. In contrast, polyphenols from blueberries were involved in the ultraviolet-activated p53/Gadd45/MDM2 DNA repair system by restoring the cell membrane potential. Inhibition of hypoxia-inducible factor-1 by saponin extracts of ginsenoside (Ginsen and Gynostemma and inhibition of S100A4 by coix polysaccharides inhibited cancer cell migration and invasion. These observations suggest that antioxidants and changes in cell membrane potential are the major driving forces that transfer signals through the cell membrane into the cytosol and nucleus, triggering gene expression, changes in cell proliferation and the induction of apoptosis or DNA repair.

Inhibition of nitric oxide synthesis enhances leukocyte rolling and adhesion in human microvasculature

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Hossain Mokarram

2012-07-01

Full Text Available Abstract Background Nitric oxide (NO is a multifunctional signaling molecule that regulates important cellular events in inflammation including leukocyte recruitment. Previous studies have shown that pharmacological inhibition of NO synthesis induces leukocyte recruitment in various in vitro and animal models. However, it is not known whether NO modulation has similar effects on leukocyte-endothelial cell interactions within the human microvasculature. The present study explored the effect of systemic L-NAME treatment on leukocyte recruitment in the SCID-hu mouse model. Methods Human skin xenografts were transplanted in SCID mice to study human leukocyte dynamics in human vasculature. Early events of human leukocyte recruitment in human vasculature were studied using intravital microscopy. NO synthesis was pharmacologically inhibited using NG-nitro-L-arginine methyl ester (L-NAME. Immunohistochemical analysis was performed to elucidate E-selectin expression in human xenograft skin. Human neutrophil-endothelial cell interactions were also studied in an in vitro flow chamber assay system. P- and E-selectin expression on cultured human umbilical vein endothelial cells (HUVECs was measured using ELISA. Platelet-activating factor (PAF synthesis was detected using a TLC-based assay. Results L-NAME treatment significantly enhanced the rolling and adhesion of human leukocytes to the human vasculature. Functional blocking of P- and E-selectins significantly inhibited rolling but not adhesion induced by inhibition of NO synthesis. Systemic L-NAME treatment enhanced E-selectin expression in human xenograft skin. L-NAME treatment significantly enhanced P- and E-selectin expression on HUVECs. L-NAME treatment did not significantly modify neutrophil rolling or adhesion to HUVECs indicating that L-NAME−induced subtle P- and E-selectin expression was insufficient to elicit dynamic neutrophil-HUVEC interactions in vitro. Moreover, synthesis of endothelial

Compound Stimulus Extinction Reduces Spontaneous Recovery in Humans

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Coelho, Cesar A. O.; Dunsmoor, Joseph E.; Phelps, Elizabeth A.

2015-01-01

Fear-related behaviors are prone to relapse following extinction. We tested in humans a compound extinction design ("deepened extinction") shown in animal studies to reduce post-extinction fear recovery. Adult subjects underwent fear conditioning to a visual and an auditory conditioned stimulus (CSA and CSB, respectively) separately…

Comparison of the inhibition potentials of icotinib and erlotinib against human UDP-glucuronosyltransferase 1A1

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Xuewei Cheng

2017-11-01

Full Text Available UDP-glucuronosyltransferase 1A1 (UGT1A1 plays a key role in detoxification of many potentially harmful compounds and drugs. UGT1A1 inhibition may bring risks of drug–drug interactions (DDIs, hyperbilirubinemia and drug-induced liver injury. This study aimed to investigate and compare the inhibitory effects of icotinib and erlotinib against UGT1A1, as well as to evaluate their potential DDI risks via UGT1A1 inhibition. The results demonstrated that both icotinib and erlotinib are UGT1A1 inhibitors, but the inhibitory effect of icotinib on UGT1A1 is weaker than that of erlotinib. The IC50 values of icotinib and erlotinib against UGT1A1-mediated NCHN-O-glucuronidation in human liver microsomes (HLMs were 5.15 and 0.68 μmol/L, respectively. Inhibition kinetic analyses demonstrated that both icotinib and erlotinib were non-competitive inhibitors against UGT1A1-mediated glucuronidation of NCHN in HLMs, with the Ki values of 8.55 and 1.23 μmol/L, respectively. Furthermore, their potential DDI risks via UGT1A1 inhibition were quantitatively predicted by the ratio of the areas under the concentration–time curve (AUC of NCHN. These findings are helpful for the medicinal chemists to design and develop next generation tyrosine kinase inhibitors with improved safety, as well as to guide reasonable applications of icotinib and erlotinib in clinic, especially for avoiding their potential DDI risks via UGT1A1 inhibition.

Comparison of the inhibition potentials of icotinib and erlotinib against human UDP-glucuronosyltransferase 1A1.

Science.gov (United States)

Cheng, Xuewei; Lv, Xia; Qu, Hengyan; Li, Dandan; Hu, Mengmeng; Guo, Wenzhi; Ge, Guangbo; Dong, Ruihua

2017-11-01

UDP-glucuronosyltransferase 1A1 (UGT1A1) plays a key role in detoxification of many potentially harmful compounds and drugs. UGT1A1 inhibition may bring risks of drug-drug interactions (DDIs), hyperbilirubinemia and drug-induced liver injury. This study aimed to investigate and compare the inhibitory effects of icotinib and erlotinib against UGT1A1, as well as to evaluate their potential DDI risks via UGT1A1 inhibition. The results demonstrated that both icotinib and erlotinib are UGT1A1 inhibitors, but the inhibitory effect of icotinib on UGT1A1 is weaker than that of erlotinib. The IC 50 values of icotinib and erlotinib against UGT1A1-mediated NCHN- O -glucuronidation in human liver microsomes (HLMs) were 5.15 and 0.68 μmol/L, respectively. Inhibition kinetic analyses demonstrated that both icotinib and erlotinib were non-competitive inhibitors against UGT1A1-mediated glucuronidation of NCHN in HLMs, with the K i values of 8.55 and 1.23 μmol/L, respectively. Furthermore, their potential DDI risks via UGT1A1 inhibition were quantitatively predicted by the ratio of the areas under the concentration-time curve (AUC) of NCHN. These findings are helpful for the medicinal chemists to design and develop next generation tyrosine kinase inhibitors with improved safety, as well as to guide reasonable applications of icotinib and erlotinib in clinic, especially for avoiding their potential DDI risks via UGT1A1 inhibition.

IN VITRO INHIBITION OF CELERY (Apium graveolens L. EXTRACT ON THE ACTIVITY OF XANTHINE OXIDASE AND DETERMINATION OF ITS ACTIVE COMPOUND

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Dyah Iswantini

2012-12-01

Full Text Available The objective of this study was to determine the inhibition effect of celery extracts toward xanthine oxidase by in vitro method, and its active compounds. Roots and herb of celery were extracted using water and ethanol solvents. Results indicated that the herbal ethanol extract had the highest inhibition effect (91.40% at 1400 ppm. The components contained in the herbal ethanol extract were then separated by column chromatography using the best eluent (chloroform : ethyl acetate at 7:3. All of the fractions had inhibition effect greater than 50%. The fraction number 4 was the one with the highest inhibition effect followed by fraction 5 with inhibition percentage of both fractions at 200 ppm were 88.62 and 85.44%, respectively. The analysis of the ultraviolet spectrum of fraction 4 showed the presence of π-π* transition which was resulted by the aromatic C=C, -OH, and C-O chromophores, and also showing the n-σ* transition which was given by -C=O chromophore. The infrared spectrum analysis indicated the presence of aromatic -C=C, -OH, and C=O functional groups. Based on the phytochemical assay and both instrumental spectrums, it was thought that the active compounds of fraction 4 and 5 were in the flavonoid group.

Prediction of human population responses to toxic compounds by a collaborative competition.

Science.gov (United States)

Eduati, Federica; Mangravite, Lara M; Wang, Tao; Tang, Hao; Bare, J Christopher; Huang, Ruili; Norman, Thea; Kellen, Mike; Menden, Michael P; Yang, Jichen; Zhan, Xiaowei; Zhong, Rui; Xiao, Guanghua; Xia, Menghang; Abdo, Nour; Kosyk, Oksana; Friend, Stephen; Dearry, Allen; Simeonov, Anton; Tice, Raymond R; Rusyn, Ivan; Wright, Fred A; Stolovitzky, Gustavo; Xie, Yang; Saez-Rodriguez, Julio

2015-09-01

The ability to computationally predict the effects of toxic compounds on humans could help address the deficiencies of current chemical safety testing. Here, we report the results from a community-based DREAM challenge to predict toxicities of environmental compounds with potential adverse health effects for human populations. We measured the cytotoxicity of 156 compounds in 884 lymphoblastoid cell lines for which genotype and transcriptional data are available as part of the Tox21 1000 Genomes Project. The challenge participants developed algorithms to predict interindividual variability of toxic response from genomic profiles and population-level cytotoxicity data from structural attributes of the compounds. 179 submitted predictions were evaluated against an experimental data set to which participants were blinded. Individual cytotoxicity predictions were better than random, with modest correlations (Pearson's r < 0.28), consistent with complex trait genomic prediction. In contrast, predictions of population-level response to different compounds were higher (r < 0.66). The results highlight the possibility of predicting health risks associated with unknown compounds, although risk estimation accuracy remains suboptimal.

Inhibition of the human liver microsomal and human cytochrome P450 1A2 and 3A4 metabolism of estradiol by deployment-related and other chemicals.

Science.gov (United States)

Usmani, Khawja A; Cho, Taehyeon M; Rose, Randy L; Hodgson, Ernest

2006-09-01

Cytochromes P450 (P450s) are major catalysts in the metabolism of xenobiotics and endogenous substrates such as estradiol (E2). It has previously been shown that E2 is predominantly metabolized in humans by CYP1A2 and CYP3A4 with 2-hydroxyestradiol (2-OHE2) the major metabolite. This study examines effects of deployment-related and other chemicals on E2 metabolism by human liver microsomes (HLM) and individual P450 isoforms. Kinetic studies using HLM, CYP3A4, and CYP1A2 showed similar affinities (Km) for E2 with respect to 2-OHE2 production. Vmax and CLint values for HLM are 0.32 nmol/min/mg protein and 7.5 microl/min/mg protein; those for CYP3A4 are 6.9 nmol/min/nmol P450 and 291 microl/min/nmol P450; and those for CYP1A2 are 17.4 nmol/min/nmol P450 and 633 microl/min/nmol P450. Phenotyped HLM use showed that individuals with high levels of CYP1A2 and CYP3A4 have the greatest potential to metabolize E2. Preincubation of HLM with a variety of chemicals, including those used in military deployments, resulted in varying levels of inhibition of E2 metabolism. The greatest inhibition was observed with organophosphorus compounds, including chlorpyrifos and fonofos, with up to 80% inhibition for 2-OHE2 production. Carbaryl, a carbamate pesticide, and naphthalene, a jet fuel component, inhibited ca. 40% of E2 metabolism. Preincubation of CYP1A2 with chlorpyrifos, fonofos, carbaryl, or naphthalene resulted in 96, 59, 84, and 87% inhibition of E2 metabolism, respectively. Preincubation of CYP3A4 with chlorpyrifos, fonofos, deltamethrin, or permethrin resulted in 94, 87, 58, and 37% inhibition of E2 metabolism. Chlorpyrifos inhibition of E2 metabolism is shown to be irreversible.

Exposure to perfluorinated compounds and human semen quality in Arctic and European populations

DEFF Research Database (Denmark)

Toft, G; Jönsson, B A G; Lindh, C H

2012-01-01

Perfluorinated compounds (PFCs) have been suspected to adversely affect human reproductive health. The aim of this study was to investigate the associations between PFC exposure and male semen quality.......Perfluorinated compounds (PFCs) have been suspected to adversely affect human reproductive health. The aim of this study was to investigate the associations between PFC exposure and male semen quality....

Inhibition of growth of human breast cancer cells in culture by neutron capture using liposomes containing 10B.

Science.gov (United States)

Yanagië, H; Kobayashi, H; Takeda, Y; Yoshizaki, I; Nonaka, Y; Naka, S; Nojiri, A; Shinnkawa, H; Furuya, Y; Niwa, H; Ariki, K; Yasuhara, H; Eriguchi, M

2002-03-01

Cell destruction in boron neutron capture therapy is effected by nuclear reaction between 10B and thermal neutrons with the release of alpha-particles (4He) and lithium-7 ions (7Li). 4He kills cells within 10 microm of the site of 4He generation, therefore it is theoretically possible to destroy tumour cells without affecting adjacent healthy tissue, given selective delivery of compounds containing 10B. Liposomes wore prepared by vortex dispersion of solutions containing 10B compounds with dried lipid films and the effects of those compounds on human breast cancer cells in culture were examined after thermal neutral irradiation. [3H]-TdR incorporation by MRKnu/nu-1 cells treated with 10B-containing liposomes showed 40% suppression compared with liposomes without 10B, at 2 x 1012 n/cm2 thermal neutron fluence. Inhibition of tumour cell growth with liposomes prepared with 100 mm 10B-compound was as significant as with those made with 500 ppm 10B solution. The concentration of 10B in liposomes was 76.5 +/- 3.4 microg/mL. Boronated liposomes can thus deliver sufficient 10B atoms to this line of breast cancer cells in culture to effect cytotoxicity and suppression of growth after thermal neutron irradiation.

Aldose Reductase Inhibitory Activity of Compounds from  Zea mays L.

Science.gov (United States)

Kim, Tae Hyeon; Kim, Jin Kyu; Kang, Young-Hee; Lee, Jae-Yong; Kang, Il Jun; Lim, Soon Sung

2013-01-01

Aldose reductase (AR) inhibitors have a considerable therapeutic potential against diabetes complications and do not increase the risk of hypoglycemia. Through bioassay-guided fractionation of an EtOH extract of the kernel from purple corn (Zea mays L.), 7 nonanthocyanin phenolic compounds (compound 1–7) and 5 anthocyanins (compound 8–12) were isolated. These compounds were investigated by rat lens aldose reductase (RLAR) inhibitory assays. Kinetic analyses of recombinant human aldose reductase (rhAR) were performed, and intracellular galactitol levels were measured. Hirsutrin, one of 12 isolated compounds, showed the most potent RLAR inhibitory activity (IC50, 4.78 μM). In the kinetic analyses using Lineweaver-Burk plots of 1/velocity and 1/substrate concentration, hirsutrin showed competitive inhibition against rhAR. Furthermore, hirsutrin inhibited galactitol formation in rat lens and erythrocytes sample incubated with a high concentration of galactose; this finding indicates that hirsutrin may effectively prevent osmotic stress in hyperglycemia. Therefore, hirsutrin derived from Zea mays L. may be a potential therapeutic agent against diabetes complications. PMID:23586057

Species used for drug testing reveal different inhibition susceptibility for 17beta-hydroxysteroid dehydrogenase type 1.

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Gabriele Möller

Full Text Available Steroid-related cancers can be treated by inhibitors of steroid metabolism. In searching for new inhibitors of human 17beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD 1 for the treatment of breast cancer or endometriosis, novel substances based on 15-substituted estrone were validated. We checked the specificity for different 17beta-HSD types and species. Compounds were tested for specificity in vitro not only towards recombinant human 17beta-HSD types 1, 2, 4, 5 and 7 but also against 17beta-HSD 1 of several other species including marmoset, pig, mouse, and rat. The latter are used in the processes of pharmacophore screening. We present the quantification of inhibitor preferences between human and animal models. Profound differences in the susceptibility to inhibition of steroid conversion among all 17beta-HSDs analyzed were observed. Especially, the rodent 17beta-HSDs 1 were significantly less sensitive to inhibition compared to the human ortholog, while the most similar inhibition pattern to the human 17beta-HSD 1 was obtained with the marmoset enzyme. Molecular docking experiments predicted estrone as the most potent inhibitor. The best performing compound in enzymatic assays was also highly ranked by docking scoring for the human enzyme. However, species-specific prediction of inhibitor performance by molecular docking was not possible. We show that experiments with good candidate compounds would out-select them in the rodent model during preclinical optimization steps. Potentially active human-relevant drugs, therefore, would no longer be further developed. Activity and efficacy screens in heterologous species systems must be evaluated with caution.

Compound 13, an α1-selective small molecule activator of AMPK, inhibits Helicobacter pylori-induced oxidative stresses and gastric epithelial cell apoptosis

International Nuclear Information System (INIS)

Zhao, Hangyong; Zhu, Huanghuang; Lin, Zhou; Lin, Gang; Lv, Guoqiang

2015-01-01

Half of the world's population experiences Helicobacter pylori (H. pylori) infection, which is a main cause of gastritis, duodenal and gastric ulcer, and gastric cancers. In the current study, we investigated the potential role of compound 13 (C13), a novel α1-selective small molecule activator of AMP-activated protein kinase (AMPK), against H. pylori-induced cytotoxicity in cultured gastric epithelial cells (GECs). We found that C13 induced significant AMPK activation, evidenced by phosphorylation of AMPKα1 and ACC (acetyl-CoA carboxylase), in both primary and transformed GECs. Treatment of C13 inhibited H. pylori-induced GEC apoptosis. AMPK activation was required for C13-mediated GEC protection. Inhibition of AMPK kinase activity by the AMPK inhibitor Compound C, or silencing AMPKα1 expression by targeted-shRNAs, alleviated C13-induced GEC protective activities against H. pylori. Significantly, C13 inhibited H. pylori-induced reactive oxygen species (ROS) production in GECs. C13 induced AMPK-dependent expression of anti-oxidant gene heme oxygenase (HO-1) in GECs. Zinc protoporphyrin (ZnPP) and tin protoporphyrin (SnPP), two HO-1 inhibitors, not only suppressed C13-mediated ROS scavenging activity, but also alleviated its activity in GECs against H. pylori. Together, these results indicate that C13 inhibits H. pylori-induced ROS production and GEC apoptosis through activating AMPK–HO–1 signaling. - Highlights: • We synthesized compound 13 (C13), a α1-selective small molecule AMPK activator. • C13-induced AMPK activation requires α1 subunit in gastric epithelial cells (GECs). • C13 enhances Helicobacter pylori-induced pro-survival AMPK activation to inhibit GEC apoptosis. • C13 inhibits H. pylori-induced reactive oxygen species (ROS) production in GECs. • AMPK-heme oxygenase (HO-1) activation is required for C13-mediated anti-oxidant activity

Compound 13, an α1-selective small molecule activator of AMPK, inhibits Helicobacter pylori-induced oxidative stresses and gastric epithelial cell apoptosis

Energy Technology Data Exchange (ETDEWEB)

Zhao, Hangyong; Zhu, Huanghuang; Lin, Zhou; Lin, Gang; Lv, Guoqiang, E-mail: lvguoqiangwuxivip@163.com

2015-08-07

Half of the world's population experiences Helicobacter pylori (H. pylori) infection, which is a main cause of gastritis, duodenal and gastric ulcer, and gastric cancers. In the current study, we investigated the potential role of compound 13 (C13), a novel α1-selective small molecule activator of AMP-activated protein kinase (AMPK), against H. pylori-induced cytotoxicity in cultured gastric epithelial cells (GECs). We found that C13 induced significant AMPK activation, evidenced by phosphorylation of AMPKα1 and ACC (acetyl-CoA carboxylase), in both primary and transformed GECs. Treatment of C13 inhibited H. pylori-induced GEC apoptosis. AMPK activation was required for C13-mediated GEC protection. Inhibition of AMPK kinase activity by the AMPK inhibitor Compound C, or silencing AMPKα1 expression by targeted-shRNAs, alleviated C13-induced GEC protective activities against H. pylori. Significantly, C13 inhibited H. pylori-induced reactive oxygen species (ROS) production in GECs. C13 induced AMPK-dependent expression of anti-oxidant gene heme oxygenase (HO-1) in GECs. Zinc protoporphyrin (ZnPP) and tin protoporphyrin (SnPP), two HO-1 inhibitors, not only suppressed C13-mediated ROS scavenging activity, but also alleviated its activity in GECs against H. pylori. Together, these results indicate that C13 inhibits H. pylori-induced ROS production and GEC apoptosis through activating AMPK–HO–1 signaling. - Highlights: • We synthesized compound 13 (C13), a α1-selective small molecule AMPK activator. • C13-induced AMPK activation requires α1 subunit in gastric epithelial cells (GECs). • C13 enhances Helicobacter pylori-induced pro-survival AMPK activation to inhibit GEC apoptosis. • C13 inhibits H. pylori-induced reactive oxygen species (ROS) production in GECs. • AMPK-heme oxygenase (HO-1) activation is required for C13-mediated anti-oxidant activity.

Inhibition of hydrolytic enzymes by gold compounds. I. beta-Glucuronidase and acid phosphatase by sodium tetrachloroaurate (III) and potassium tetrabromoaurate (III).

Science.gov (United States)

Lee, M T; Ahmed, T; Friedman, M E

1989-01-01

Purified bovine liver beta-glucuronidase (beta-D-glucuronide glucuronohydrolase, EC 3.2.1.32) and wheat germ acid phosphatase (orthophosphoric monoesterphosphohydrolase, EC 3.1.3.2) were inhibited with freshly dissolved and 24 h aquated tetrahaloaurate (III) compounds. Rate and equilibrium inhibition constants were measured. From this data two acid phosphatases species were observed. Equilibrium inhibition constants ranged from 1 to 12.5 microM for the various gold compounds toward both enzymes. The first order rate constants ranged between 0.005 and 0.04 min.-1 for most reactions with the exception of the fast reacting acid phosphatase which had values as high as 2.6 and 2.8 min.-1. It is observed that the beta-glucuronidase is rapidly inhibited during the equilibrium phase before the more slower reaction covalent bond formation takes place. The acid phosphatases form the covalent bonds more rapidly, especially the faster reacting species suggesting a unique difference in the active site geometry to that of the more slowly reacting species. The tightly bonded gold (III)-enzyme complex is probably the reason for its toxicity and non-anti-inflammatory use as a drug.

Identification of small molecule compounds that inhibit the HIF-1 signaling pathway

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Sun Yi

2009-12-01

Full Text Available Abstract Background Hypoxia-inducible factor-1 (HIF-1 is the major hypoxia-regulated transcription factor that regulates cellular responses to low oxygen environments. HIF-1 is composed of two subunits: hypoxia-inducible HIF-1α and constitutively-expressed HIF-1β. During hypoxic conditions, HIF-1α heterodimerizes with HIF-1β and translocates to the nucleus where the HIF-1 complex binds to the hypoxia-response element (HRE and activates expression of target genes implicated in cell growth and survival. HIF-1α protein expression is elevated in many solid tumors, including those of the cervix and brain, where cells that are the greatest distance from blood vessels, and therefore the most hypoxic, express the highest levels of HIF-1α. Therapeutic blockade of the HIF-1 signaling pathway in cancer cells therefore provides an attractive strategy for development of anticancer drugs. To identify small molecule inhibitors of the HIF-1 pathway, we have developed a cell-based reporter gene assay and screened a large compound library by using a quantitative high-throughput screening (qHTS approach. Results The assay is based upon a β-lactamase reporter under the control of a HRE. We have screened approximate 73,000 compounds by qHTS, with each compound tested over a range of seven to fifteen concentrations. After qHTS we have rapidly identified three novel structural series of HIF-1 pathway Inhibitors. Selected compounds in these series were also confirmed as inhibitors in a HRE β-lactamase reporter gene assay induced by low oxygen and in a VEGF secretion assay. Three of the four selected compounds tested showed significant inhibition of hypoxia-induced HIF-1α accumulation by western blot analysis. Conclusion The use of β-lactamase reporter gene assays, in combination with qHTS, enabled the rapid identification and prioritization of inhibitors specific to the hypoxia induced signaling pathway.

Microencapsulated bitter compounds (from Gentiana lutea) reduce daily energy intakes in humans

NARCIS (Netherlands)

Mennella, Ilario; Fogliano, Vincenzo; Ferracane, Rosalia; Arlorio, Marco; Pattarino, Franco; Vitaglione, Paola

2016-01-01

Mounting evidence showed that bitter-tasting compounds modulate eating behaviour through bitter taste receptors in the gastrointestinal tract. This study aimed at evaluating the influence of microencapsulated bitter compounds on human appetite and energy intakes. A microencapsulated bitter

Eugenol and its synthetic analogues inhibit cell growth of human cancer cells (Part I)

Energy Technology Data Exchange (ETDEWEB)

Carrasco A, H.; Cardona, W. [Universidad Andres Bello, Vina del Mar (Chile). Dept. de Ciencias Quimicas]. E-mail: hcarrasco@unab.cl; Espinoza C, L.; Gallardo, C.; Catalan M, K. [Universidad Tecnica Federico Santa Maria, Valparaiso (Chile). Dept. de Quimica; Cardile, V.; Lombardo, L. [University of Catania (Italy). Dept. of Physiological Sciences; Cuellar F, M. [Universidad de Valparaiso (Chile). Facultad de Farmacia; Russo, A. [University of Catania (Italy). Dept. of Biological Chemistry, Medical Chemistry and Molecular Biology

2008-07-01

Eugenol (4-allyl-2-methoxyphenol) (1) has been reported to possess antioxidant and anticancer properties. In an attempt to enhance intrinsic activity of this natural compound, some derivatives were synthesized. Eugenol was extracted from cloves oil and further, the eugenol analogues (2-6) were obtained through acetylation and nitration reactions. Eugenol (1) and its analogues (2-6) were examined by in vitro model of cancer using two human cancer cell lines: DU-145 (androgeninsensitive prostate cancer cells) and KB (oral squamous carcinoma cells). Cell viability, by tetrazolium salts assay, was measured. Lactic dehydrogenase (LDH) release was also investigated to evaluate the presence of cell toxicity as a result of cell disruption, subsequent to membrane rupture. In the examined cancer cells, all compounds showed cell-growth inhibition activity. The obtained results demonstrate that the compounds 5-allyl-3-nitrobenzene-1,2-diol (3) and 4-allyl- 2-methoxy-5-nitrophenyl acetate (5) were significantly (p < 0,001) more active than eugenol, with IC{sub 50} values in DU-145 cells of 19.02 x 10{sup -6} and 21.5 x 10{sup -6} mol L{sup -1}, respectively, and in KB cells of 18.11 x 10{sup -6} and 21.26 x 10{sup -6} mol L{sup -1}, respectively, suggesting that the presence of nitro and hydroxyl groups could be important in the activity of these compounds. In addition, our results seem to indicate that apoptotic cell demise appears to be induced in KB and DU-145 cells. In fact, in our experimental conditions, no statistically significant increase in LDH release was observed in cancer cells treated with eugenol and its analogues. (author)

Anti-human rhinoviral activity of polybromocatechol compounds isolated from the rhodophyta, Neorhodomela aculeata.

Science.gov (United States)

Park, Soon-Hye; Song, Jae-Hyoung; Kim, Taejung; Shin, Woon-Seob; Park, Gab Man; Lee, Seokjoon; Kim, Young-Joo; Choi, Pilju; Kim, Heejin; Kim, Hui-Seong; Kwon, Dur-Han; Choi, Hwa Jung; Ham, Jungyeob

2012-10-01

An extract of the red alga, Neorhodomela aculeata, exhibited antiviral activity against human rhinoviruses. Bioassay-guided purification was performed to yield six compounds, which were subsequently identified as lanosol (1) and five polybromocatechols (2-6) by spectroscopic methods, including 1D and 2D NMR and mass spectrometric analyses. Structurally, all of these compounds, except compound 5, contain one or two 2,3-dibromo-4,5-dihydroxyphenyl moieties. In a biological activity assay, compound 1 was found to possess antiviral activity with a 50% inhibitory concentration (IC₅₀) of 2.50 μg/mL against HRV2. Compound 3 showed anti-HRV2 activity, with an IC₅₀ of 7.11 μg/mL, and anti-HRV3 activity, with an IC₅₀ of 4.69 μg/mL, without demonstrable cytotoxicity at a concentration of 20 μg/mL. Collectively, the results suggest that compounds 1 and 3 are candidates for novel therapeutics against two different groups of human rhinovirus.

Fatty acid synthase inhibition in human breast cancer cells leads to malonyl-CoA-induced inhibition of fatty acid oxidation and cytotoxicity.

Science.gov (United States)

Thupari, J N; Pinn, M L; Kuhajda, F P

2001-07-13

Inhibition of fatty acid synthase (FAS) induces apoptosis in human breast cancer cells in vitro and in vivo without toxicity to proliferating normal cells. We have previously shown that FAS inhibition causes a rapid increase in malonyl-CoA levels identifying malonyl-CoA as a potential trigger of apoptosis. In this study we further investigated the role of malonyl-CoA during FAS inhibition. We have found that: [i] inhibition of FAS with cerulenin causes carnitine palmitoyltransferase-1 (CPT-1) inhibition and fatty acid oxidation inhibition in MCF-7 human breast cancer cells likely mediated by elevation of malonyl-CoA; [ii] cerulenin cytotoxicity is due to the nonphysiological state of increased malonyl-CoA, decreased fatty acid oxidation, and decreased fatty acid synthesis; and [iii] the cytotoxic effect of cerulenin can be mimicked by simultaneous inhibition of CPT-1, with etomoxir, and fatty acid synthesis with TOFA, an acetyl-CoA carboxylase (ACC) inhibitor. This study identifies CPT-1 and ACC as two new potential targets for cancer chemotherapy. Copyright 2001 Academic Press.

6-Shogaol, an active compound of ginger, alleviates allergic dermatitis-like skin lesions via cytokine inhibition by activating the Nrf2 pathway

Energy Technology Data Exchange (ETDEWEB)

Park, Gunhyuk, E-mail: uranos5@kiom.re.kr [The K-herb Research Center, Korea Institute of Oriental Medicine, 1672 Yuseong-daero, Yuseong-gu, Daejeon 34054 (Korea, Republic of); Oh, Dal-Seok [The K-herb Research Center, Korea Institute of Oriental Medicine, 1672 Yuseong-daero, Yuseong-gu, Daejeon 34054 (Korea, Republic of); Lee, Mi Gi; Lee, Chang Eon [Major in Cosmeceutical Science, Division of Bio-technology and Convergence, Daegu Haany University, Gyeongsan (Korea, Republic of); Kim, Yong-ung, E-mail: ykim@dhu.ac.kr [Department of Pharmaceutical Engineering, College of Biomedical Science, Daegu Haany University (Korea, Republic of)

2016-11-01

Allergic dermatitis (AD) clinically presents with skin erythematous plaques, eruption, and elevated serum IgE, and T helper cell type 2 and 1 (Th2 and Th1) cytokine levels. 6-Shogaol [1-(4-hydroxy-methoxyphenyl)-4-decen-one], a pungent compound isolated from ginger, has shown anti-inflammatory effects, but its inhibitory effects on AD are unknown. The aim of this study was to examine whether 6-shogaol inhibits AD-like skin lesions and their underlying mechanism in vivo and in vitro. An AD-like response was induced by tumor necrosis factor-α (TNF-α) + IFN-γ in human keratinocytes or by 2,4-dinitrochlorobenzene (DNCB) in mice. In vivo, 6-shogaol inhibited the development of DNCB-induced AD-like skin lesions and scratching behavior, and showed significant reduction in Th2/1-mediated inflammatory cytokines, IgE, TNF-α, IFN-γ, thymus and activation-regulated chemokine, IL-1, 4, 12, and 13, cyclooxygenase-2, and nitric oxide synthase levels. In vitro, 6-shogaol inhibited reactive oxygen species (ROS) and mitogen-activated protein kinases (MAPKs) signaling, and increased the levels of total glutathione, heme oxygenase-1, and quinone 1 via nuclear factor erythroid 2 related factor 2 (Nrf2) activation. 6-Shogaol can alleviate AD-like skin lesions by inhibiting immune mediators via regulating the ROS/MAPKs/Nrf2 signaling pathway, and may be an effective alternative therapy for AD. - Highlights: • 6-Shogaol inhibited Th2/1-mediated inflammatory mediators in vitro and in vivo. • 6-Shogaol regulated ROS/MAPKs/Nrf2 signaling pathway. • 6-Shogaol can protect against the development of AD-like skin lesions.

6-Shogaol, an active compound of ginger, alleviates allergic dermatitis-like skin lesions via cytokine inhibition by activating the Nrf2 pathway

International Nuclear Information System (INIS)

Park, Gunhyuk; Oh, Dal-Seok; Lee, Mi Gi; Lee, Chang Eon; Kim, Yong-ung

2016-01-01

Allergic dermatitis (AD) clinically presents with skin erythematous plaques, eruption, and elevated serum IgE, and T helper cell type 2 and 1 (Th2 and Th1) cytokine levels. 6-Shogaol [1-(4-hydroxy-methoxyphenyl)-4-decen-one], a pungent compound isolated from ginger, has shown anti-inflammatory effects, but its inhibitory effects on AD are unknown. The aim of this study was to examine whether 6-shogaol inhibits AD-like skin lesions and their underlying mechanism in vivo and in vitro. An AD-like response was induced by tumor necrosis factor-α (TNF-α) + IFN-γ in human keratinocytes or by 2,4-dinitrochlorobenzene (DNCB) in mice. In vivo, 6-shogaol inhibited the development of DNCB-induced AD-like skin lesions and scratching behavior, and showed significant reduction in Th2/1-mediated inflammatory cytokines, IgE, TNF-α, IFN-γ, thymus and activation-regulated chemokine, IL-1, 4, 12, and 13, cyclooxygenase-2, and nitric oxide synthase levels. In vitro, 6-shogaol inhibited reactive oxygen species (ROS) and mitogen-activated protein kinases (MAPKs) signaling, and increased the levels of total glutathione, heme oxygenase-1, and quinone 1 via nuclear factor erythroid 2 related factor 2 (Nrf2) activation. 6-Shogaol can alleviate AD-like skin lesions by inhibiting immune mediators via regulating the ROS/MAPKs/Nrf2 signaling pathway, and may be an effective alternative therapy for AD. - Highlights: • 6-Shogaol inhibited Th2/1-mediated inflammatory mediators in vitro and in vivo. • 6-Shogaol regulated ROS/MAPKs/Nrf2 signaling pathway. • 6-Shogaol can protect against the development of AD-like skin lesions.

Aerobic Biofilms Grown from Athabasca Watershed Sediments Are Inhibited by Increasing Concentrations of Bituminous Compounds

Science.gov (United States)

Lawrence, John R.; Sanschagrin, Sylvie; Roy, Julie L.; Swerhone, George D. W.; Korber, Darren R.; Greer, Charles W.

2013-01-01

Sediments from the Athabasca River and its tributaries naturally contain bitumen at various concentrations, but the impacts of this variation on the ecology of the river are unknown. Here, we used controlled rotating biofilm reactors in which we recirculated diluted sediments containing various concentrations of bituminous compounds taken from the Athabasca River and three tributaries. Biofilms exposed to sediments having low and high concentrations of bituminous compounds were compared. The latter were 29% thinner, had a different extracellular polysaccharide composition, 67% less bacterial biomass per μm2, 68% less cyanobacterial biomass per μm2, 64% less algal biomass per μm2, 13% fewer protozoa per cm2, were 21% less productive, and had a 33% reduced content in chlorophyll a per mm2 and a 20% reduction in the expression of photosynthetic genes, but they had a 23% increase in the expression of aromatic hydrocarbon degradation genes. Within the Bacteria, differences in community composition were also observed, with relatively more Alphaproteobacteria and Betaproteobacteria and less Cyanobacteria, Bacteroidetes, and Firmicutes in biofilms exposed to high concentrations of bituminous compounds. Altogether, our results suggest that biofilms that develop in the presence of higher concentrations of bituminous compounds are less productive and have lower biomass, linked to a decrease in the activities and abundance of photosynthetic organisms likely due to inhibitory effects. However, within this general inhibition, some specific microbial taxa and functional genes are stimulated because they are less sensitive to the inhibitory effects of bituminous compounds or can degrade and utilize some bitumen-associated compounds. PMID:24056457

Retinoid inhibition of in vitro invasion of human amnion basement membrane by human tumor cells

International Nuclear Information System (INIS)

Fazely, F.

1988-01-01

The effects measured were the inhibition of tumor cell migration through the basement membrane (BM) and tumor cell degradative enzyme activity on 3 H-proline labeled collagenous and non collagenous components of the BM. The human lung carcinoma A549 or the human Ewing's sarcoma TC-106 cell lines treated with retinoids for two days were incubated on the BM in the absence of retinoids. A dose-dependent inhibition of cell invasion was produced by retinoids. Among the retinoids tested the most powerful was retinol acetate which inhibited invasion by 50% of A549 cells at a concentration of 0.09 μg/ml, and TC-106 cells at 0.08 μg/ml. Retinol acetate inhibited A549 and TC-106 cell growth by approximately 50% at levels almost 100-fold higher than those needed for antiinvasive activity. Retinol acetate was about 20 times more potent than retinoic acid and 30 times more than retinol palmitate. Furthermore, A549 cells treated with retinol acetate, under conditions whereby an anti-invasive state was induced,showed an increase in the number of cellular retinoic acid binding proteins (CRABP), a decrease in the activity of type IV collagenase and ectosialyltransferase, and no change in the activity of transglutaminase

Marine Compound Catunaregin Inhibits Angiogenesis through the Modulation of Phosphorylation of Akt and eNOS in vivo and in vitro

Directory of Open Access Journals (Sweden)

Jun-Xiu Liu

2014-05-01

Full Text Available Angiogenesis is the formation of blood vessels from pre-existing vasculature. Excessive or uncontrolled angiogenesis is a major contributor to many pathological conditions whereas inhibition of aberrant angiogenesis is beneficial to patients with pathological angiogenesis. Catunaregin is a core of novel marine compound isolated from mangrove associate. The potential anti-angiogenesis of catunaregin was investigated in human umbilical vein endothelial cells (HUVECs and zebrafish. HUVECs were treated with different concentrations of catunaregin in the presence or absence of VEGF. The angiogenic phenotypes including cell invasion cell migration and tube formation were evaluated following catunaregin treatment in HUVECs. The possible involvement of AKT, eNOS and ERK1/2 in catunaregin-induced anti-angiogenesis was explored using Western blotting. The anti-angiogenesis of catunaregin was further tested in the zebrafish embryo neovascularization and caudal fin regeneration assays. We found that catunaregin dose-dependently inhibited angiogenesis in both HUVECs and zebrafish embryo neovascularization and zebrafish caudal fin regeneration assays. In addition, catunaregin significantly decreased the phosphorylation of Akt and eNOS, but not the phosphorylation of ERK1/2. The present work demonstrates that catunaregin exerts the anti-angiogenic activity at least in part through the regulation of the Akt and eNOS signaling pathways.

Screening of pharmacologically active small molecule compounds identifies antifungal agents against Candida biofilms

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Takao eWatamoto

2015-12-01

Full Text Available Candida species have emerged as important and common opportunistic human pathogens, particularly in immunocompromised individuals. The current antifungal therapies either have toxic side effects or are insufficiently effect. The aim of this study is develop new small-molecule antifungal compounds by library screening methods using C. albicans, and to evaluate their antifungal effects on Candida biofilms and cytotoxic effects on human cells. Wild-type C. albicans strain SC5314 was used in library screening. To identify antifungal compounds, we screened a small-molecule library of 1,280 pharmacologically active compounds (LOPAC1280TM using an antifungal susceptibility test (AST. To investigate the antifungal effects of the hit compounds, ASTs were conducted using Candida strains in various growth modes, including biofilms. We tested the cytotoxicity of the hit compounds using human gingival fibroblast (hGF cells to evaluate their clinical safety. Only 35 compounds were identified by screening, which inhibited the metabolic activity of C. albicans by >50%. Of these, 26 compounds had fungistatic effects and 9 compounds had fungicidal effects on C. albicans. Five compounds, BAY11-7082, BAY11-7085, sanguinarine chloride hydrate, ellipticine and CV-3988, had strong fungicidal effects and could inhibit the metabolic activity of Candida biofilms. However, BAY11-7082, BAY11-7085, sanguinarine chloride hydrate and ellipticine were cytotoxic to hGF cells at low concentrations. CV-3988 showed no cytotoxicity at a fungicidal concentration.Four of the compounds identified, BAY11-7082, BAY11-7085, sanguinarine chloride hydrate and ellipticine, had toxic effects on Candida strains and hGF cells. In contrast, CV-3988 had fungicidal effects on Candida strains, but low cytotoxic effects on hGF cells. Therefore, this screening reveals agent, CV-3988 that was previously unknown to be antifungal agent, which could be a novel therapies for superficial mucosal

Biochemical and mass spectrometric characterization of human N-acylethanolamine-hydrolyzing acid amidase inhibition.

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Jay M West

Full Text Available The mechanism of inactivation of human enzyme N-acylethanolamine-hydrolyzing acid amidase (hNAAA, with selected inhibitors identified in a novel fluorescent based assay developed for characterization of both reversible and irreversible inhibitors, was investigated kinetically and using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS. 1-Isothiocyanatopentadecane (AM9023 was found to be a potent, selective and reversible hNAAA inhibitor, while two others, 5-((biphenyl-4-ylmethyl-N,N-dimethyl-2H-tetrazole-2-carboxamide (AM6701 and N-Benzyloxycarbonyl-L-serine β-lactone (N-Cbz-serine β-lactone, inhibited hNAAA in a covalent and irreversible manner. MS analysis of the hNAAA/covalent inhibitor complexes identified modification only of the N-terminal cysteine (Cys126 of the β-subunit, confirming a suggested mechanism of hNAAA inactivation by the β-lactone containing inhibitors. These experiments provide direct evidence of the key role of Cys126 in hNAAA inactivation by different classes of covalent inhibitors, confirming the essential role of cysteine for catalysis and inhibition in this cysteine N-terminal nucleophile hydrolase enzyme. They also provide a methodology for the rapid screening and characterization of large libraries of compounds as potential inhibitors of NAAA, and subsequent characterization or their mechanism through MALDI-TOF MS based bottom up-proteomics.

Inhibition of adipocytogenesis by canonical WNT signaling in human mesenchymal stem cells

International Nuclear Information System (INIS)

Shen, Longxiang; Glowacki, Julie; Zhou, Shuanhu

2011-01-01

The WNT signaling pathway plays important roles in the self-renewal and differentiation of mesenchymal stem cells (MSCs). Little is known about WNT signaling in adipocyte differentiation of human MSCs. In this study, we tested the hypothesis that canonical and non-canonical WNTs differentially regulate in vitro adipocytogenesis in human MSCs. The expression of adipocyte gene PPARγ2, lipoprotein lipase, and adipsin increased during adipocytogenesis of hMSCs. Simultaneously, the expression of canonical WNT2, 10B, 13, and 14 decreased, whereas non-canonical WNT4 and 11 increased, and WNT5A was unchanged. A small molecule WNT mimetic, SB-216763, increased accumulation of β-catenin protein, inhibited induction of WNT4 and 11 and inhibited adipocytogenesis. In contrast, knockdown of β-catenin with siRNA resulted in spontaneous adipocytogenesis. These findings support the view that canonical WNT signaling inhibits and non-canonical WNT signaling promotes adipocytogenesis in adult human marrow-derived mesenchymal stem cells.

A rapid and sensitive screening system for human type I collagen with the aim of discovering potent anti-aging or anti-fibrotic compounds.

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Hashem, Md Abul; Jun, Kyu-Yeon; Lee, Eunyoung; Lim, Soyun; Choo, Hea-Young Park; Kwon, Youngjoo

2008-12-31

This study was undertaken with the aim of developing an easy and quick means of analyzing the effect of various compounds on the synthesis and secretion of human type I collagen at the protein level. A modification of the ELISA method was used on HFF-1 cells. For the proof of concept, we used thirteen compounds most of which are known to be antioxidants. Each compound was tested at concentrations of 0, 10 and 100 microM on HFF-1 cells for 24 h. Thirteen sets of experiments for each compound were performed in ANOVA with three replicates. Duncan multiple range test (DMRT) was used to compare the mean values obtained from the treatment groups. From the results it was concluded that Vitamin C, undecylenic acid, conjugated linoleic acid, glycolic acid, and citric acid at 100 microM concentration could be used for anti-wrinkling or protection from premature aging, which requires enhancement of collagen synthesis. Lactic acid, EGCG, resveratrol, and retinol that can inhibit collagen synthesis effectively in a dose-dependent manner may be used for anti-fibrosis treatment purposes.

Minocycline and doxycycline, but not other tetracycline-derived compounds, protect liver cells from chemical hypoxia and ischemia/reperfusion injury by inhibition of the mitochondrial calcium uniporter

International Nuclear Information System (INIS)

Schwartz, Justin; Holmuhamedov, Ekhson; Zhang, Xun; Lovelace, Gregory L.; Smith, Charles D.; Lemasters, John J.

2013-01-01

Minocycline, a tetracycline-derived compound, mitigates damage caused by ischemia/reperfusion (I/R) injury. Here, 19 tetracycline-derived compounds were screened in comparison to minocycline for their ability to protect hepatocytes against damage from chemical hypoxia and I/R injury. Cultured rat hepatocytes were incubated with 50 μM of each tetracycline-derived compound 20 min prior to exposure to 500 μM iodoacetic acid plus 1 mM KCN (chemical hypoxia). In other experiments, hepatocytes were incubated in anoxic Krebs–Ringer–HEPES buffer at pH 6.2 for 4 h prior to reoxygenation at pH 7.4 (simulated I/R). Tetracycline-derived compounds were added 20 min prior to reperfusion. Ca 2+ uptake was measured in isolated rat liver mitochondria incubated with Fluo-5N. Cell killing after 120 min of chemical hypoxia measured by propidium iodide (PI) fluorometry was 87%, which decreased to 28% and 42% with minocycline and doxycycline, respectively. After I/R, cell killing at 120 min decreased from 79% with vehicle to 43% and 49% with minocycline and doxycycline. No other tested compound decreased killing. Minocycline and doxycycline also inhibited mitochondrial Ca 2+ uptake and suppressed the Ca 2+ -induced mitochondrial permeability transition (MPT), the penultimate cause of cell death in reperfusion injury. Ru360, a specific inhibitor of the mitochondrial calcium uniporter (MCU), also decreased cell killing after hypoxia and I/R and blocked mitochondrial Ca 2+ uptake and the MPT. Other proposed mechanisms, including mitochondrial depolarization and matrix metalloprotease inhibition, could not account for cytoprotection. Taken together, these results indicate that minocycline and doxycycline are cytoprotective by way of inhibition of MCU. - Highlights: • Minocycline and doxycycline are the only cytoprotective tetracyclines of those tested • Cytoprotective tetracyclines inhibit the MPT and mitochondrial calcium and iron uptake. • Cytoprotective tetracyclines protect

Minocycline and doxycycline, but not other tetracycline-derived compounds, protect liver cells from chemical hypoxia and ischemia/reperfusion injury by inhibition of the mitochondrial calcium uniporter

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Schwartz, Justin; Holmuhamedov, Ekhson; Zhang, Xun; Lovelace, Gregory L.; Smith, Charles D. [Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC (United States); Lemasters, John J., E-mail: JJLemasters@musc.edu [Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC (United States); Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC (United States)

2013-11-15

Minocycline, a tetracycline-derived compound, mitigates damage caused by ischemia/reperfusion (I/R) injury. Here, 19 tetracycline-derived compounds were screened in comparison to minocycline for their ability to protect hepatocytes against damage from chemical hypoxia and I/R injury. Cultured rat hepatocytes were incubated with 50 μM of each tetracycline-derived compound 20 min prior to exposure to 500 μM iodoacetic acid plus 1 mM KCN (chemical hypoxia). In other experiments, hepatocytes were incubated in anoxic Krebs–Ringer–HEPES buffer at pH 6.2 for 4 h prior to reoxygenation at pH 7.4 (simulated I/R). Tetracycline-derived compounds were added 20 min prior to reperfusion. Ca{sup 2+} uptake was measured in isolated rat liver mitochondria incubated with Fluo-5N. Cell killing after 120 min of chemical hypoxia measured by propidium iodide (PI) fluorometry was 87%, which decreased to 28% and 42% with minocycline and doxycycline, respectively. After I/R, cell killing at 120 min decreased from 79% with vehicle to 43% and 49% with minocycline and doxycycline. No other tested compound decreased killing. Minocycline and doxycycline also inhibited mitochondrial Ca{sup 2+} uptake and suppressed the Ca{sup 2+}-induced mitochondrial permeability transition (MPT), the penultimate cause of cell death in reperfusion injury. Ru360, a specific inhibitor of the mitochondrial calcium uniporter (MCU), also decreased cell killing after hypoxia and I/R and blocked mitochondrial Ca{sup 2+} uptake and the MPT. Other proposed mechanisms, including mitochondrial depolarization and matrix metalloprotease inhibition, could not account for cytoprotection. Taken together, these results indicate that minocycline and doxycycline are cytoprotective by way of inhibition of MCU. - Highlights: • Minocycline and doxycycline are the only cytoprotective tetracyclines of those tested • Cytoprotective tetracyclines inhibit the MPT and mitochondrial calcium and iron uptake. • Cytoprotective

Inhibition of aflatoxin biosynthesis in Aspergillus flavus by phenolic compounds extracted of Piper betle L.

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Yazdani, Darab; Mior Ahmad, Zainal Abidin; Yee How, Tan; Jaganath, Indu Bala; Shahnazi, Sahar

2013-12-01

Food contamination by aflatoxins is an important food safety concern for agricultural products. In order to identify and develop novel antifungal agents, several plant extracts and isolated compounds have been evaluated for their bioactivities. Anti-infectious activity of Piper betle used in traditional medicine of Malaysia has been reported previously. Crude methanol extract from P. betel powdered leaves was partitioned between chloroform and water. The fractions were tested against A. flavus UPMC 89, a strong aflatoxin producing strain. Inhibition of mycelial growth and aflatoxin biosynthesis were tested by disk diffusion and macrodillution techniques, respectively. The presence of aflatoxin was determined by thin-layer chromatography (TLC) and fluorescence spectroscopy techniques using AFB1 standard. The chloroform soluble compounds were identified using HPLC-Tandem mass spectrometry technique. The results, evaluated by measuring the mycelial growth and quantification of aflatoxin B1(AFLB1) production in broth medium revealed that chloroform soluble compounds extract from P. betle dried leaves was able to block the aflatoxin biosynthesis pathway at concentration of 500μg/ml without a significant effect on mycelium growth. In analyzing of this effective fractions using HPLC-MS(2) with ESI ionization technique, 11 phenolic compounds were identified. The results showed that the certain phenolic compounds are able to decline the aflatoxin production in A. flavus with no significant effect on the fungus mycelia growth. The result also suggested P. betle could be used as potential antitoxin product.

Lauroside B, a megastigmane glycoside from Laurus nobilis (bay laurel) leaves, induces apoptosis in human melanoma cell lines by inhibiting NF-κB activation.

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Panza, Elisabetta; Tersigni, Mariaroberta; Iorizzi, Maria; Zollo, Franco; De Marino, Simona; Festa, Carmen; Napolitano, Maria; Castello, Giuseppe; Ialenti, Armando; Ianaro, Angela

2011-02-25

Malignant melanoma is a highly aggressive tumor that frequently resists chemotherapy, so the search for new agents for its treatment is of great importance. In the present study, the antiproliferative propensity against human melanoma cell lines of lauroside B (1), a megastigmane glycoside isolated from Laurus nobilis (bay laurel) leaves, was investigated. This compound suppressed the proliferation of three human melanoma cell lines, namely, A375, WM115, and SK-Mel-28. The 1-induced inhibition of human melanoma cell proliferation was due to the induction of apoptosis, as demonstrated by FACS analysis with annexin V/PI staining and confirmed by activation of caspase-3 and by the cleavage of poly(ADP-ribose) polymerase (PARP). Growing evidence implicates NF-κB as an important contributor to metastasis and increased chemoresistance of melanoma. Thus, it was hypothesized that 1-induced apoptosis could be associated with suppression of NF-κB activation. The results showed that exposure of human melanoma cells to 1 inhibited IκB-α degradation and constitutive NF-κB DNA-binding activity as well as the expression, regulated by NF-κB, of two antiapoptotic genes, XIAP and c-FLIP. Induction of apoptosis by 1 in human aggressive melanoma cell lines has a potential high biological value.

Vaginal Lactobacillus Inhibits HIV-1 Replication in Human Tissues Ex Vivo

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Rogers A. Ñahui Palomino

2017-05-01

Full Text Available Lactobacillus species, which dominate vaginal microbiota of healthy reproductive-age women, lower the risks of sexually transmitted infections, including the risk of human immunodeficiency virus (HIV acquisition. The exact mechanisms of this protection remain to be understood. Here, we investigated these mechanisms in the context of human cervico-vaginal and lymphoid tissues ex vivo. We found that all six Lactobacillus strains tested in these systems significantly suppressed HIV type-1 (HIV-1 infection. We identified at least three factors that mediated this suppression: (i Acidification of the medium. The pH of the undiluted medium conditioned by lactobacilli was between 3.8 and 4.6. Acidification of the culture medium with hydrochloric acid (HCl to this pH in control experiments was sufficient to abrogate HIV-1 replication. However, the pH of the Lactobacillus-conditioned medium (CM diluted fivefold, which reached ∼6.9, was also suppressive for HIV-1 infection, while in control experiments HIV-1 infection was not abrogated when the pH of the medium was brought to 6.9 through the use of HCl. This suggested the existence of other factors responsible for HIV-1 inhibition by lactobacilli. (ii Lactic acid. There was a correlation between the concentration of lactic acid in the Lactobacillus-CM and its ability to suppress HIV-1 infection in human tissues ex vivo. Addition of lactic acid isomers D and L to tissue culture medium at the concentration that corresponded to their amount released by lactobacilli resulted in HIV-1 inhibition. Isomer L was produced in higher quantities than isomer D and was mostly responsible for HIV-1 inhibition. These results indicate that lactic acid, in particular its L-isomer, inhibits HIV-1 independently of lowering of the pH. (iii Virucidal effect. Incubation of HIV-1 in Lactobacillus-CM significantly suppressed viral infectivity for human tissues ex vivo. Finally, lactobacilli adsorb HIV-1, serving as a sink

Anti-Human Rhinoviral Activity of Polybromocatechol Compounds Isolated from the Rhodophyta, Neorhodomela aculeata

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Hui-Seong Kim

2012-10-01

Full Text Available An extract of the red alga, Neorhodomela aculeata, exhibited antiviral activity against human rhinoviruses. Bioassay-guided purification was performed to yield six compounds, which were subsequently identified as lanosol (1 and five polybromocatechols (2–6 by spectroscopic methods, including 1D and 2D NMR and mass spectrometric analyses. Structurally, all of these compounds, except compound 5, contain one or two 2,3-dibromo-4,5-dihydroxyphenyl moieties. In a biological activity assay, compound 1 was found to possess antiviral activity with a 50% inhibitory concentration (IC50 of 2.50 μg/mL against HRV2. Compound 3 showed anti-HRV2 activity, with an IC50 of 7.11 μg/mL, and anti-HRV3 activity, with an IC50 of 4.69 μg/mL, without demonstrable cytotoxicity at a concentration of 20 μg/mL. Collectively, the results suggest that compounds 1 and 3 are candidates for novel therapeutics against two different groups of human rhinovirus.

Harman inhibits the removal of pyrimidine dimers from the DNA of human cells

International Nuclear Information System (INIS)

Castellani, A.; Setlow, R.B.

1981-01-01

Normal human fibroblasts were UV-irradiated and incubated for 6 hr with harman. The losses of sites, in the extracted DNA, sensitive to a UV specific endonuclease were determined as precision measures of the excision of UV-induced pyrimidine dimers. Harman inhibited excision, rising from approx. 30% inhibition at 200 μM to 75% inhibition at 500 μM

A new strategy to inhibit the excision reaction catalysed by HIV-1 reverse transcriptase: compounds that compete with the template–primer

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Cruchaga, Carlos; Anso, Elena; Font, María; Martino, Virginia S.; Rouzaut, Ana; Martinez-Irujo, Juan J.

2007-01-01

Inhibitors of the excision reaction catalysed by HIV-1 RT (reverse transcriptase) represent a promising approach in the fight against HIV, because these molecules would interfere with the main mechanism of resistance of this enzyme towards chain-terminating nucleotides. Only a limited number of compounds have been demonstrated to inhibit this reaction to date, including NNRTIs (non-nucleoside RT inhibitors) and certain pyrophosphate analogues. We have found previously that 2GP (2-O-galloylpunicalin), an antiviral compound extracted from the leaves of Terminalia triflora, was able to inhibit both the RT and the RNase H activities of HIV-1 RT without affecting cell proliferation or viability. In the present study, we show that 2GP also inhibited the ATP- and PPi-dependent phosphorolysis catalysed by wild-type and AZT (3′-azido-3′-deoxythymidine)-resistant enzymes at sub-micromolar concentrations. Kinetic and direct-binding analysis showed that 2GP was a non-competitive inhibitor against the nucleotide substrate, whereas it competed with the binding of RT to the template–primer (Kd=85 nM). As expected from its mechanism of action, 2GP was active against mutations conferring resistance to NNRTIs and AZT. The combination of AZT with 2GP was highly synergistic when tested in the presence of pyrophosphate, indicating that the inhibition of RT-catalysed phosphorolysis was responsible for the synergy found. Although other RT inhibitors that compete with the template–primer have been described, this is the first demonstration that these compounds can be used to block the excision of chain terminating nucleotides, providing a rationale for their combination with nucleoside analogues. PMID:17355225

Lipid-Lowering Pharmaceutical Clofibrate Inhibits Human Sweet Taste

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Kochem, Matthew

2017-01-01

T1R2-T1R3 is a heteromeric receptor that binds sugars, high potency sweeteners, and sweet taste blockers. In rodents, T1R2-T1R3 is largely responsible for transducing sweet taste perception. T1R2-T1R3 is also expressed in non-taste tissues, and a growing body of evidence suggests that it helps regulate glucose and lipid metabolism. It was previously shown that clofibric acid, a blood lipid-lowering drug, binds T1R2-T1R3 and inhibits its activity in vitro. The purpose of this study was to determine whether clofibric acid inhibits sweetness perception in humans and is, therefore, a T1R2-T1R3 antagonist in vivo. Fourteen participants rated the sweetness intensity of 4 sweeteners (sucrose, sucralose, Na cyclamate, acesulfame K) across a broad range of concentrations. Each sweetener was prepared in solution neat and in mixture with either clofibric acid or lactisole. Clofibric acid inhibited sweetness of every sweetener. Consistent with competitive binding, inhibition by clofibric acid was diminished with increasing sweetener concentration. This study provides in vivo evidence that the lipid-lowering drug clofibric acid inhibits sweetness perception and is, therefore, a T1R carbohydrate receptor inhibitor. Our results are consistent with previous in vitro findings. Given that T1R2-T1R3 may in part regulate glucose and lipid metabolism, future studies should investigate the metabolic effects of T1R inhibition. PMID:27742692

IL-17 inhibits chondrogenic differentiation of human mesenchymal stem cells.

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Masahiro Kondo

Full Text Available OBJECTIVE: Mesenchymal stem cells (MSCs can differentiate into cells of mesenchymal lineages, such as osteoblasts and chondrocytes. Here we investigated the effects of IL-17, a key cytokine in chronic inflammation, on chondrogenic differentiation of human MSCs. METHODS: Human bone marrow MSCs were pellet cultured in chondrogenic induction medium containing TGF-β3. Chondrogenic differentiation was detected by cartilage matrix accumulation and chondrogenic marker gene expression. RESULTS: Over-expression of cartilage matrix and chondrogenic marker genes was noted in chondrogenic cultures, but was inhibited by IL-17 in a dose-dependent manner. Expression and phosphorylation of SOX9, the master transcription factor for chondrogenesis, were induced within 2 days and phosphorylated SOX9 was stably maintained until day 21. IL-17 did not alter total SOX9 expression, but significantly suppressed SOX9 phosphorylation in a dose-dependent manner. At day 7, IL-17 also suppressed the activity of cAMP-dependent protein kinase A (PKA, which is known to phosphorylate SOX9. H89, a selective PKA inhibitor, also suppressed SOX9 phosphorylation, expression of chondrogenic markers and cartilage matrix, and also decreased chondrogenesis. CONCLUSIONS: IL-17 inhibited chondrogenesis of human MSCs through the suppression of PKA activity and SOX9 phosphorylation. These results suggest that chondrogenic differentiation of MSCs can be inhibited by a mechanism triggered by IL-17 under chronic inflammation.

New cytotoxic and anti-inflammatory compounds isolated from Morus alba L.

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Qin, Jing; Fan, Min; He, Juan; Wu, Xing-De; Peng, Li-Yan; Su, Jia; Cheng, Xiao; Li, Yan; Kong, Ling-Mei; Li, Rong-Tao; Zhao, Qin-Shi

2015-01-01

Six Diels-Alder adducts (1-6) and nine prenylated flavanones (7-15) were isolated from the root bark of Morus alba L. Among them, soroceal B (1) and sanggenol Q (7) were new compounds. Their structures were elucidated on the basis of extensive spectroscopic methods, including 1D and 2D NMR techniques. Compounds 1-3, 9, 10, 12, 13 and 15 exhibited cytotoxic activity against five human tumour lines and compound 2 inhibited significantly selective cytotoxic activities towards HL-60 and AGS cells with IC50 of 3.4 and 3.6 μM. Compounds 3, 5, 9 and 12 exhibited moderate inhibitory activity against nitric oxide production in LPS-activated RAW264.7.

Antioxidants inhibit SAA formation and pro-inflammatory cytokine release in a human cell model of alkaptonuria.

Science.gov (United States)

Spreafico, Adriano; Millucci, Lia; Ghezzi, Lorenzo; Geminiani, Michela; Braconi, Daniela; Amato, Loredana; Chellini, Federico; Frediani, Bruno; Moretti, Elena; Collodel, Giulia; Bernardini, Giulia; Santucci, Annalisa

2013-09-01

Alkaptonuria (AKU) is an ultra-rare autosomal recessive disease that currently lacks an appropriate therapy. Recently we provided experimental evidence that AKU is a secondary serum amyloid A (SAA)-based amyloidosis. The aim of the present work was to evaluate the use of antioxidants to inhibit SAA amyloid and pro-inflammatory cytokine release in AKU. We adopted a human chondrocytic cell AKU model to evaluate the anti-amyloid capacity of a set of antioxidants that had previously been shown to counteract ochronosis in a serum AKU model. Amyloid presence was evaluated by Congo red staining. Homogentisic acid-induced SAA production and pro-inflammatory cytokine release (overexpressed in AKU patients) were evaluated by ELISA and multiplex systems, respectively. Lipid peroxidation was evaluated by means of a fluorescence-based assay. Our AKU model allowed us to prove the efficacy of ascorbic acid combined with N-acetylcysteine, taurine, phytic acid and lipoic acid in significantly inhibiting SAA production, pro-inflammatory cytokine release and membrane lipid peroxidation. All the tested antioxidant compounds were able to reduce the production of amyloid and may be the basis for establishing new therapies for AKU amyloidosis.

Tributyltin or triphenyltin inhibits aromatase activity in the human granulosa-like tumor cell line KGN.

Science.gov (United States)

Saitoh, M; Yanase, T; Morinaga, H; Tanabe, M; Mu, Y M; Nishi, Y; Nomura, M; Okabe, T; Goto, K; Takayanagi, R; Nawata, H

2001-11-23

The superimposition of male sex organs (penis and vas deferens) in a female gastropod, called imposex, is widely attributed to the exposure to tributyltin (TBT) compounds, used world-wide in antifouling paints for ships. It has been hypothesized that the TBT-induced imposex is mediated by an increasing androgen level relative to the estrogen level, namely a decreased conversion of androgens to estrogens (i.e., aromatization). In the present study, we tested this hypothesis by examining the effects of TBT or triphenyltin (TPT) on the aromatase activity in a cultured human granulosa-like tumor cell line, KGN, which was recently established by our group. Treatment with more than 1000 ng/ml TBT compounds was very toxic to the cells and caused immediate cell death within 24 h, while 200 ng/ml was found to cause apoptosis of the cells. Treatment of the KGN cells for more than 48 h with 20 ng/ml TBT or TPT, which is a concentration level reported to cause imposex in marine species, did not affect cell proliferation but significantly suppressed the aromatase activity determined by a [(3)H]H(2)O release assay. Treatment with 20 ng/ml TBT compounds for 7 days also resulted in a reduction of the E2 production from Delta 4-androstenedione stimulated by db-cAMP. The changes in the aromatase activity by TBT compounds were associated with comparable changes in P450arom mRNA assessed by RT-PCR. The luciferase activity of the P450arom promoter II (1 kb) decreased after the addition of 20 ng/ml TBT compounds in transfected KGN cells either in a basic state or in states stimulated by db-cAMP. The Ad4BP-dependent increase in the luciferase activity of P450arom promoter II was also downregulated by such treatments. These results indicate that TBT compounds inhibited the aromatase activity and also decreased the P450arom mRNA level at the transcriptional level in KGN cells. The direct inhibitory effect of TBT compounds on the aromatase activity may therefore partly explain the induction

The rational design of a novel potent analogue of the 5’-AMP-activated protein kinase inhibitor compound C with improved selectivity and cellular activity

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Machrouhi, Fouzia; Ouhamou, Nouara; Laderoute, Keith; Calaoagan, Joy; Bukhtiyarova, Marina; Ehrlich, Paula J.; Klon, Anthony E.

2010-01-01

We have designed and synthesized analogues of compound C, a non-specific inhibitor of 5’-AMP-activated protein kinase (AMPK), using a computational fragment-based drug design (FBDD) approach. Synthesizing only twenty-seven analogues yielded a compound that was equipotent to compound C in the inhibition of the human AMPK (hAMPK) α2 subunit in the heterotrimeric complex in vitro, exhibited significantly improved selectivity against a subset of relevant kinases, and demonstrated enhanced cellular inhibition of AMPK. PMID:20932747

Inhibition and kinetic studies of cellulose- and hemicellulose-degrading enzymes of Ganoderma boninense by naturally occurring phenolic compounds.

Science.gov (United States)

Surendran, A; Siddiqui, Y; Ali, N S; Manickam, S

2018-06-01

Ganoderma sp, the causal pathogen of the basal stem rot (BSR) disease of oil palm, secretes extracellular hydrolytic enzymes. These play an important role in the pathogenesis of BSR by nourishing the pathogen through the digestion of cellulose and hemicellulose of the host tissue. Active suppression of hydrolytic enzymes secreted by Ganoderma boninense by various naturally occurring phenolic compounds and estimation of their efficacy on pathogen suppression is focused in this study. Ten naturally occurring phenolic compounds were assessed for their inhibitory effect on the hydrolytic enzymes of G. boninense. The enzyme kinetics (V max and K m ) and the stability of the hydrolytic enzymes were also characterized. The selected compounds had shown inhibitory effect at various concentrations. Two types of inhibitions namely uncompetitive and noncompetitive were observed in the presence of phenolic compounds. Among all the phenolic compounds tested, benzoic acid was the most effective compound suppressive to the growth and production of hydrolytic enzymes secreted by G. boninense. The phenolic compounds as inhibitory agents can be a better replacement for the metal ions which are known as conventional inhibitors till date. The three hydrolytic enzymes were stable in a wide range of pH and temperature. These findings highlight the efficacy of the applications of phenolic compounds to control Ganoderma. The study has proved a replacement for chemical controls of G. boninense with naturally occurring phenolic compounds. © 2018 The Society for Applied Microbiology.

Mechanisms of inhibition of zinc-finger transcription factors by selenium compounds ebselen and selenite.

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Larabee, Jason L; Hocker, James R; Hanas, Jay S

2009-03-01

The anti-inflammatory selenium compounds, ebselen (2-phenyl-1,2-benzisoselenazol-3[2H]-one) and selenite, were found to alter the DNA binding mechanisms and structures of cysteine-rich zinc-finger transcription factors. As assayed by DNase I protection, DNA binding by TFIIIA (transcription factor IIIA, prototypical Cys(2)His(2) zinc finger protein), was inhibited by micromolar amounts of ebselen. In a gel shift assay, ebselen inhibited the Cys(2)His(2) zinc finger-containing DNA binding domain (DBD) of the NF-kappaB mediated transcription factor Sp1. Ebselen also inhibited DNA binding by the p50 subunit of the pro-inflammatory Cys-containing NF-kappaB transcription factor. Electrospray ionization mass spectrometry (ESI-MS) was utilized to elucidate mechanisms of chemical interaction between ebselen and a zinc-bound Cys(2)His(2) zinc finger polypeptide modeled after the third finger of Sp1 (Sp1-3). Exposing Sp1-3 to micromolar amounts of ebselen resulted in Zn(2+) release from this peptide and the formation of a disulfide bond by oxidation of zinc finger SH groups, the likely mechanism for DNA binding inhibition. Selenite was shown by ESI-MS to also eject zinc from Sp1-3 as well as induce disulfide bond formation through SH oxidation. The selenite-dependent inhibition/oxidation mechanism differed from that of ebselen by inducing the formation of a stable selenotrisulfide bond. Selenite-induced selenotrisulfide formation was dependent upon the structure of the Cys(2)His(2) zinc finger as alteration in the finger structure enhanced this reaction as well as selenite-dependent zinc release. Ebselen and selenite-dependent inhibition/oxidation of Cys-rich zinc finger proteins, with concomitant release of zinc and finger structural changes, points to mechanisms at the atomic and protein level for selenium-induced alterations in Cys-rich proteins, and possible amelioration of certain inflammatory, neurodegenerative, and oncogenic responses.

Phenolic Compounds of Cereals and Their Antioxidant Capacity.

Science.gov (United States)

Van Hung, Pham

2016-01-01

Phenolic compounds play an important role in health benefits because of their highly antioxidant capacity. In this review, total phenolic contents (TPCs), phenolic acid profile and antioxidant capacity of the extracted from wheat, corn, rice, barley, sorghum, rye, oat, and millet, which have been recently reported, are summarized. The review shows clearly that cereals contain a number of phytochemicals including phenolics, flavonoids, anthocyanins, etc. The phytochemicals of cereals significantly exhibit antioxidant activity as measured by trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-1-picrylhydrazyl radical scavenging, reducing power, oxygen radical absorbance capacity (ORAC), inhibition of oxidation of human low-density lipoprotein (LDL) cholesterol and DNA, Rancimat, inhibition of photochemilumenescence (PCL), and iron(II) chelation activity. Thus, the consumption of whole grains is considered to have significantly health benefits in prevention from chronic diseases such as cardiovascular disease, diabetes, and cancer because of the contribution of phenolic compounds existed. In addition, the extracts from cereal brans are considered to be used as a source of natural antioxidants.

Malonyl-coenzyme-A is a potential mediator of cytotoxicity induced by fatty-acid synthase inhibition in human breast cancer cells and xenografts.

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Pizer, E S; Thupari, J; Han, W F; Pinn, M L; Chrest, F J; Frehywot, G L; Townsend, C A; Kuhajda, F P

2000-01-15

A biologically aggressive subset of human breast cancers and other malignancies is characterized by elevated fatty-acid synthase (FAS) enzyme expression, elevated fatty acid (FA) synthesis, and selective sensitivity to pharmacological inhibition of FAS activity by cerulenin or the novel compound C75. In this study, inhibition of FA synthesis at the physiologically regulated step of carboxylation of acetyl-CoA to malonyl-CoA by 5-(tetradecyloxy)-2-furoic acid (TOFA) was not cytotoxic to breast cancer cells in clonogenic assays. FAS inhibitors induced a rapid increase in intracellular malonyl-CoA to several fold above control levels, whereas TOFA reduced intracellular malonyl-CoA by 60%. Simultaneous exposure of breast cancer cells to TOFA and an FAS inhibitor resulted in significantly reduced cytotoxicity and apoptosis. Subcutaneous xenografts of MCF7 breast cancer cells in nude mice treated with C75 showed FA synthesis inhibition, apoptosis, and inhibition of tumor growth to less than 1/8 of control volumes, without comparable toxicity in normal tissues. The data suggest that differences in intermediary metabolism render tumor cells susceptible to toxic fluxes in malonyl-CoA, both in vitro and in vivo.

Enhancing and inhibiting effects of aromatic compounds on luminol-dimethylsulfoxide-OH(-) chemiluminescence and determination of intermediates in oxidative hair dyes by HPLC with chemiluminescence detection.

Science.gov (United States)

Zhou, Jian; Xu, Hong; Wan, Guo-Hui; Duan, Chun-Feng; Cui, Hua

2004-10-08

The effect of 36 aromatic compounds on the luminol-dimethylsulfoxide-OH(-) chemiluminescence (CL) was systematically studied. It was found that dihydroxybenzenes, and ortho- and para-substituted aminophenols and phenylenediamines inhibited the CL and phenols with three or more than three hydroxyls except phloroglucin tended to enhance the CL. The CL inhibition and enhancement was proposed to be dependent on whether superoxide anion radical (O(2)(-)) was competitively consumed by compounds in the CL system. Trihydroxybenzenes were capable of generating superoxide anion radical, leading to the CL enhancement, whereas dihydroxybenzenes were superoxide anion radical scavenger, causing the CL inhibition. Based on the inhibited CL, a novel method for the simultaneous determination of p-phenylenediamine, o-phenylenediamine, p-aminophenol, o-aminophenol, resorcinol and hydroquinone by high-performance liquid chromatography coupled with chemiluminescence detection was developed. The method has been successfully applied to determine intermediates in oxidative hair dyes and wastewater of shampooing after hair dyed.

Pseudogymnoascus destructans: Causative Agent of White-Nose Syndrome in Bats Is Inhibited by Safe Volatile Organic Compounds.

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Padhi, Sally; Dias, Itamar; Korn, Victoria L; Bennett, Joan W

2018-04-10

White-nose syndrome (WNS) is caused by Pseudogymnoascus destructans , a psychrophilic fungus that infects hibernating bats and has caused a serious decline in some species. Natural aroma compounds have been used to control growth of fungal food storage pathogens, so we hypothesized that a similar strategy could work for control of P. destructans . The effectiveness of exposure to low concentrations of the vapor phase of four of these compounds was tested on mycelial plugs and conidiospores at temperatures of 5, 10 and 15 °C. Here we report the efficacy of vapor phase mushroom alcohol (1-octen-3-ol) for inhibiting mycelial and conidiospore growth of P. destructans at 0.4 and 0.8 µmol/mL and demonstrate that the R enantiomer of this compound is more effective than the S enantiomer, supporting the finding that biological systems can be sensitive to stereochemistry. Further, we report that vapor phase leaf aldehyde ( trans -2-hexenal), a common aroma compound associated with cut grass odors and also the major volatile compound in extra virgin olive oil, is more effective than mushroom alcohol. At 0.05 µmol/mL, trans -2-hexenal is fungicidal to both conidiospores and mycelia of P. destructans .

Pseudogymnoascus destructans: Causative Agent of White-Nose Syndrome in Bats Is Inhibited by Safe Volatile Organic Compounds

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Sally Padhi

2018-04-01

Full Text Available White-nose syndrome (WNS is caused by Pseudogymnoascus destructans, a psychrophilic fungus that infects hibernating bats and has caused a serious decline in some species. Natural aroma compounds have been used to control growth of fungal food storage pathogens, so we hypothesized that a similar strategy could work for control of P. destructans. The effectiveness of exposure to low concentrations of the vapor phase of four of these compounds was tested on mycelial plugs and conidiospores at temperatures of 5, 10 and 15 °C. Here we report the efficacy of vapor phase mushroom alcohol (1-octen-3-ol for inhibiting mycelial and conidiospore growth of P. destructans at 0.4 and 0.8 µmol/mL and demonstrate that the R enantiomer of this compound is more effective than the S enantiomer, supporting the finding that biological systems can be sensitive to stereochemistry. Further, we report that vapor phase leaf aldehyde (trans-2-hexenal, a common aroma compound associated with cut grass odors and also the major volatile compound in extra virgin olive oil, is more effective than mushroom alcohol. At 0.05 µmol/mL, trans-2-hexenal is fungicidal to both conidiospores and mycelia of P. destructans.

Leishmania infantum Exoproducts Inhibit Human Invariant NKT Cell Expansion and Activation

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Renata Belo

2017-06-01

Full Text Available Leishmania infantum is one of the major parasite species associated with visceral leishmaniasis, a severe form of the disease that can become lethal if untreated. This obligate intracellular parasite has developed diverse strategies to escape the host immune response, such as exoproducts (Exo carrying a wide range of molecules, including parasite virulence factors, which are potentially implicated in early stages of infection. Herein, we report that L. infantum Exo and its two fractions composed of extracellular vesicles (EVs and vesicle-depleted-exoproducts (VDEs inhibit human peripheral blood invariant natural killer T (iNKT cell expansion in response to their specific ligand, the glycolipid α-GalactosylCeramide (α-GalCer, as well as their capacity to promptly produce IL-4 and IFNγ. Using plate-bound CD1d and α-GalCer, we found that Exo, EV, and VDE fractions reduced iNKT cell activation in a dose-dependent manner, suggesting that they prevented α-GalCer presentation by CD1d molecules. This direct effect on CD1d was confirmed by the observation that CD1d:α-GalCer complex formation was impaired in the presence of Exo, EV, and VDE fractions. Furthermore, lipid extracts from the three compounds mimicked the inhibition of iNKT cell activation. These lipid components of L. infantum exoproducts, including EV and VDE fractions, might compete for CD1-binding sites, thus blocking iNKT cell activation. Overall, our results provide evidence for a novel strategy through which L. infantum can evade immune responses of mammalian host cells by preventing iNKT lymphocytes from recognizing glycolipids in a TCR-dependent manner.

Sickle erythrocytes inhibit human endothelial cell DNA synthesis

International Nuclear Information System (INIS)

Weinstein, R.; Zhou, M.A.; Bartlett-Pandite, A.; Wenc, K.

1990-01-01

Patients with sickle cell anemia experience severe vascular occlusive phenomena including acute pain crisis and cerebral infarction. Obstruction occurs at both the microvascular and the arterial level, and the clinical presentation of vascular events is heterogeneous, suggesting a complex etiology. Interaction between sickle erythrocytes and the endothelium may contribute to vascular occlusion due to alteration of endothelial function. To investigate this hypothesis, human vascular endothelial cells were overlaid with sickle or normal erythrocytes and stimulated to synthesize DNA. The erythrocytes were sedimented onto replicate monolayers by centrifugation for 10 minutes at 17 g to insure contact with the endothelial cells. Incorporation of 3H-thymidine into endothelial cell DNA was markedly inhibited during contact with sickle erythrocytes. This inhibitory effect was enhanced more than twofold when autologous sickle plasma was present during endothelial cell labeling. Normal erythrocytes, with or without autologous plasma, had a modest effect on endothelial cell DNA synthesis. When sickle erythrocytes in autologous sickle plasma were applied to endothelial monolayers for 1 minute, 10 minutes, or 1 hour and then removed, subsequent DNA synthesis by the endothelial cells was inhibited by 30% to 40%. Although adherence of sickle erythrocytes to the endothelial monolayers was observed under these experimental conditions, the effect of sickle erythrocytes on endothelial DNA synthesis occurred in the absence of significant adherence. Hence, human endothelial cell DNA synthesis is partially inhibited by contact with sickle erythrocytes. The inhibitory effect of sickle erythrocytes occurs during a brief (1 minute) contact with the endothelial monolayers, and persists for at least 6 hours of 3H-thymidine labeling

Cysteine-independent activation/inhibition of heme oxygenase-2

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Dragic Vukomanovic

2016-01-01

Full Text Available Reactive thiols of cysteine (cys residues in proteins play a key role in transforming chemical reactivity into a biological response. The heme oxygenase-2 (HO-2 isozyme contains two cys residues that have been implicated in binding of heme and also the regulation of its activity. In this paper, we address the question of a role for cys residues for the HO-2 inhibitors or activators designed in our laboratory. We tested the activity of full length recombinant human heme oxygenase-2 (FL-hHO-2 and its analog in which cys265 and cys282 were both replaced by alanine to determine the effect on activation by menadione (MD and inhibition by QC-2350. Similar inhibition by QC-2350 and almost identical activation by MD was observed for both recombinant FL-hHO-2s. Our findings are interpreted to mean that thiols of FL-hHO-2s are not involved in HO-2 activation or inhibition by the compounds that have been designed and identified by us. Activation or inhibition of HO-2 by our compounds should be attributed to a mechanism other than altering binding affinity of HO-2 for heme through cys265 and cys282.

Cysteine-independent activation/inhibition of heme oxygenase-2.

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Vukomanovic, Dragic; Rahman, Mona N; Maines, Mahin D; Ozolinš, Terence Rs; Szarek, Walter A; Jia, Zongchao; Nakatsu, Kanji

2016-03-01

Reactive thiols of cysteine (cys) residues in proteins play a key role in transforming chemical reactivity into a biological response. The heme oxygenase-2 (HO-2) isozyme contains two cys residues that have been implicated in binding of heme and also the regulation of its activity. In this paper, we address the question of a role for cys residues for the HO-2 inhibitors or activators designed in our laboratory. We tested the activity of full length recombinant human heme oxygenase-2 (FL-hHO-2) and its analog in which cys265 and cys282 were both replaced by alanine to determine the effect on activation by menadione (MD) and inhibition by QC-2350. Similar inhibition by QC-2350 and almost identical activation by MD was observed for both recombinant FL-hHO-2s. Our findings are interpreted to mean that thiols of FL-hHO-2s are not involved in HO-2 activation or inhibition by the compounds that have been designed and identified by us. Activation or inhibition of HO-2 by our compounds should be attributed to a mechanism other than altering binding affinity of HO-2 for heme through cys265 and cys282.

Inhibition of isolated human myometrium contractility by minoxidil and reversal by glibenclamide.

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Prabhakaran, S S; Dhanasekar, K R; Thomas, E; Jose, R; Peedicayil, J; Samuel, P

2010-03-01

This study investigated the ability of the antihypertensive drug minoxidil to inhibit potassium chloride (KCl)-induced contractility of the isolated human myometrium. Twelve strips of myometrium obtained from 12 patients who underwent hysterectomy were triggered to contract with 55 mM KCl before and after incubation with 3 concentrations (1, 3 and 10 microM) of minoxidil. The percent inhibition by minoxidil on the extent of contraction, and the area under the contractile curve of KCl-induced contraction of the myometrial strips was determined. Furthermore, the effect of 10 microM glibenclamide on the inhibition generated by 3 microM minoxidil on KCl-induced contractility was studied. It was found that minoxidil produced a concentration-dependent inhibition of KCl-induced contractility of the myometrium and that glibenclamide reversed this inhibitory effect. These results suggest that the inhibitory effect of minoxidil on isolated human myometrium contractility may prove useful in clinical conditions requiring relaxation of the myometrium. 2010 Prous Science, S.A.U. or its licensors. All rights reserved.

Inhibition of inflammatory and proliferative responses of human keratinocytes exposed to the sesquiterpene lactones dehydrocostuslactone and costunolide.

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Claudia Scarponi

Full Text Available The imbalance of the intracellular redox state and, in particular, of the glutathione (GSH/GSH disulfide couple homeostasis, is involved in the pathogenesis of a number of diseases. In many skin diseases, including psoriasis, oxidative stress plays an important role, as demonstrated by the observation that treatments leading to increase of the local levels of oxidant species ameliorate the disease. Recently, dehydrocostuslactone (DCE and costunolide (CS, two terpenes naturally occurring in many plants, have been found to exert various anti-inflammatory and pro-apoptotic effects on different human cell types. These compounds decrease the level of the intracellular GSH by direct interaction with it, and, therefore, can alter cellular redox state. DCE and CS can trigger S-glutathionylation of various substrates, including the transcription factor STAT3 and JAK1/2 proteins. In the present study, we investigated on the potential role of DCE and CS in regulating inflammatory and proliferative responses of human keratinocytes to cytokines. We demonstrated that DCE and CS decreased intracellular GSH levels in human keratinocytes, as well as inhibited STAT3 and STAT1 phosphorylation and activation triggered by IL-22 or IFN-γ, respectively. Consequently, DCE and CS decreased the IL-22- and IFN-γ-induced expression of inflammatory and regulatory genes in keratinocytes, including CCL2, CXCL10, ICAM-1 and SOCS3. DCE and CS also inhibited proliferation and cell-cycle progression-related gene expression, as well as they promoted cell cycle arrest and apoptosis. In parallel, DCE and CS activated the anti-inflammatory EGFR and ERK1/2 molecules in keratinocytes, and, thus, wound healing in an in vitro injury model. In light of our findings, we can hypothesize that the employment of DCE and CS in psoriasis could efficiently counteract the pro-inflammatory effects of IFN-γ and IL-22 on keratinocytes, revert the apoptosis-resistant phenotype, as well as inhibit

Metal inhibition of human alkylpurine-DNA-N-glycosylase activityin base excision repair

Energy Technology Data Exchange (ETDEWEB)

Wang, Ping; Guliaev, Anton B.; Hang, Bo

2006-02-28

Cadmium (Cd{sup 2+}), nickel (Ni{sup 2+}) and cobalt (Co{sup 2+}) are human and/or animal carcinogens. Zinc (Zn{sup 2+}) is not categorized as a carcinogen, and rather an essential element to humans. Metals were recently shown to inhibit DNA repair proteins that use metals for their function and/or structure. Here we report that the divalent ions Cd{sup 2+}, Ni{sup 2+}, and Zn{sup 2+} can inhibit the activity of a recombinant human N-methylpurine-DNA glycosylase (MPG) toward a deoxyoligonucleotide with ethenoadenine (var epsilonA). MPG removes a variety of toxic/mutagenic alkylated bases and does not require metal for its catalytic activity or structural integrity. At concentrations starting from 50 to 1000 {micro}M, both Cd{sup 2+} and Zn{sup 2+} showed metal-dependent inhibition of the MPG catalytic activity. Ni{sup 2+} also inhibited MPG, but to a lesser extent. Such an effect can be reversed with EDTA addition. In contrast, Co{sup 2+} and Mg{sup 2+} did not inhibit the MPG activity in the same dose range. Experiments using HeLa cell-free extracts demonstrated similar patterns of inactivation of the var epsilonA excision activity by the same metals. Binding of MPG to the substrate was not significantly affected by Cd{sup 2+}, Zn{sup 2+}, and Ni{sup 2+} at concentrations that show strong inhibition of the catalytic function, suggesting that the reduced catalytic activity is not due to altered MPG binding affinity to the substrate. Molecular dynamics (MD) simulations with Zn{sup 2+} showed that the MPG active site has a potential binding site for Zn{sup 2+}, formed by several catalytically important and conserved residues. Metal binding to such a site is expected to interfere with the catalytic mechanism of this protein. These data suggest that inhibition of MPG activity may contribute to metal genotoxicity and depressed repair of alkylation damage by metals in vivo.

Concentration and distribution of dioxins and related compounds in various human organs

Energy Technology Data Exchange (ETDEWEB)

Iida, T.; Hirakawa, H.; Hori, T.; Tobiishi, K.; Matsueda, T. [Fukuoka Inst. of Health and Environmental Sciences, Dazaifu, Fukuoka (Japan); Todaka, T. [Japan Food Hygiene Association, Tokyo (Japan); Watanabe, S. [Tokyo Univ. of Agriculture, Tokyo (Japan); Yamada, T. [Keio Univ. School of Medicine, Tokyo (Japan)

2004-09-15

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and non-ortho coplanar polychlorinated biphenyls (Non-Co-PCBs) and mono-ortho coplanar polychlorinated biphenyls (Mono-Co-PCBs) accumulate in the human body due to their highly lipophilic properties. In recent years, there has been some concern about the potential health effects of dioxins and related chemicals for the general population of humans. Although there exists an enormous amount of data on this subject, most of it is from breast milk and blood, due to ease of collection; information concerning concentrations and distribution in various human organs hardly exists. Therefore, new data concerning various human tissues is required to evaluate the pathophysiological significance of dioxins and related compounds in humans. The aim of this study was to investigate the concentration levels and distribution of dioxins and related compounds in various human organ tissues. We previously reported on the concentration levels in the human liver and adipose tissues from 28 donors. In this paper, we determined the concentrations of dioxin-like isomers in 8 organs, including blood, lungs, liver, bile, spleen, pancreas, kidney and mesentery fat from 20 donors.

Human neural tuning estimated from compound action potentials in normal hearing human volunteers

Science.gov (United States)

Verschooten, Eric; Desloovere, Christian; Joris, Philip X.

2015-12-01

The sharpness of cochlear frequency tuning in humans is debated. Evoked otoacoustic emissions and psychophysical measurements suggest sharper tuning in humans than in laboratory animals [15], but this is disputed based on comparisons of behavioral and electrophysiological measurements across species [14]. Here we used evoked mass potentials to electrophysiologically quantify tuning (Q10) in humans. We combined a notched noise forward masking paradigm [9] with the recording of trans tympanic compound action potentials (CAP) from masked probe tones in awake human and anesthetized monkey (Macaca mulatta). We compare our results to data obtained with the same paradigm in cat and chinchilla [16], and find that CAP-Q10values in human are ˜1.6x higher than in cat and chinchilla and ˜1.3x higher than in monkey. To estimate frequency tuning of single auditory nerve fibers (ANFs) in humans, we derive conversion functions from ANFs in cat, chinchilla, and monkey and apply these to the human CAP measurements. The data suggest that sharp cochlear tuning is a feature of old-world primates.

MiR-1254 inhibits proliferation, migration and invasion of human ...

African Journals Online (AJOL)

MiR-1254 inhibits proliferation, migration and invasion of human brain tumour cell lines. ... The transcripts were analysed by real-time polymerase chain reaction (RT-PCR) ... Over-expression of miR- 1254 also led to significant decrease in cell ...

Inhibition of Oncogenic Transcription Factor REL by the Natural Product Derivative Calafianin Monomer 101 Induces Proliferation Arrest and Apoptosis in Human B-Lymphoma Cell Lines.

Science.gov (United States)

Yeo, Alan T; Chennamadhavuni, Spandan; Whitty, Adrian; Porco, John A; Gilmore, Thomas D

2015-04-23

Increased activity of transcription factor NF-κB has been implicated in many B-cell lymphomas. We investigated effects of synthetic compound calafianin monomer (CM101) on biochemical and biological properties of NF-κB. In human 293 cells, CM101 selectively inhibited DNA binding by overexpressed NF-κB subunits REL (human c-Rel) and p65 as compared to NF-κB p50, and inhibition of REL and p65 DNA binding by CM101 required a conserved cysteine residue. CM101 also inhibited DNA binding by REL in human B-lymphoma cell lines, and the sensitivity of several B-lymphoma cell lines to CM101-induced proliferation arrest and apoptosis correlated with levels of cellular and nuclear REL. CM101 treatment induced both phosphorylation and decreased expression of anti-apoptotic protein Bcl-XL, a REL target gene product, in sensitive B-lymphoma cell lines. Ectopic expression of Bcl-XL protected SUDHL-2 B-lymphoma cells against CM101-induced apoptosis, and overexpression of a transforming mutant of REL decreased the sensitivity of BJAB B-lymphoma cells to CM101-induced apoptosis. Lipopolysaccharide-induced activation of NF-κB signaling upstream components occurred in RAW264.7 macrophages at CM101 concentrations that blocked NF-κB DNA binding. Direct inhibitors of REL may be useful for treating B-cell lymphomas in which REL is active, and may inhibit B-lymphoma cell growth at doses that do not affect some immune-related responses in normal cells.

Inhibition of adipogenesis and leptin production in 3T3-L1 adipocytes by a derivative of meridianin C

Energy Technology Data Exchange (ETDEWEB)

Park, Yu-Kyoung [Department of Molecular Medicine, College of Medicine, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of); Lee, Tae-Yoon [Department of Microbiology, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-gu, Daegu 705-717 (Korea, Republic of); Choi, Jong-Soon [Division of Life Science, Korea Basic Science Institute, 169-148 Gwahakro, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Hong, Victor Sukbong [Department of Chemistry, College of Natural Sciences, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of); Lee, Jinho, E-mail: jinho@gw.kmu.ac.kr [Department of Chemistry, College of Natural Sciences, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of); Park, Jong-Wook, E-mail: j303nih@dsmc.or.kr [Department of Immunology, College of Medicine, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of); Jang, Byeong-Churl, E-mail: jangbc123@gw.kmu.ac.kr [Department of Molecular Medicine, College of Medicine, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of)

2014-10-03

Highlights: • Compound 7b, a meridianin C derivative, inhibits adipogenesis. • Compound 7b inhibits C/EBP-α, PPAR-γ, FAS, STAT-3, and STAT-5 in 3T3-L1 adipocytes. • Compound 7b inhibits leptin, but not adiponectin, expression in 3T3-L1 adipocytes. • Compound 7b thus may have therapeutic potential against obesity. - Abstract: Meridianin C, a marine alkaloid, is a potent protein kinase inhibitor and has anti-cancer activity. We have recently developed a series of meridianin C derivatives (compound 7a–7j) and reported their proviral integration Moloney Murine Leukemia Virus (pim) kinases’ inhibitory and anti-proliferative effects on human leukemia cells. Here we investigated the effect of these meridianin C derivatives on adipogenesis. Strikingly, among the derivatives tested, compound 7b most strongly inhibited lipid accumulation during the differentiation of 3T3-L1 preadipocytes into adipocytes. However, meridianin C treatment was largely cytotoxic to 3T3-L1 adipocytes. On mechanistic levels, compound 7b reduced not only the expressions of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), and fatty acid synthase (FAS) but also the phosphorylation levels of signal transducer and activator of transcription-3 (STAT-3) and STAT-5 during adipocyte differentiation. Moreover, compound 7b repressed leptin, but not adiponectin, expression during adipocyte differentiation. Collectively, these findings demonstrate that a meridianin C derivative inhibits adipogenesis by down-regulating expressions and/or phosphorylations of C/EBP-α, PPAR-γ, FAS, STAT-3 and STAT-5.

Human monoamine oxidase is inhibited by tobacco smoke: β-carboline alkaloids act as potent and reversible inhibitors

International Nuclear Information System (INIS)

Herraiz, Tomas; Chaparro, Carolina

2005-01-01

Monoamine oxidase (MAO) is a mitochondrial outer-membrane flavoenzyme involved in brain and peripheral oxidative catabolism of neurotransmitters and xenobiotic amines, including neurotoxic amines, and a well-known target for antidepressant and neuroprotective drugs. Recently, positron emission tomography imaging has shown that smokers have a much lower activity of peripheral and brain MAO-A (30%) and -B (40%) isozymes compared to non-smokers. This MAO inhibition results from a pharmacological effect of smoke, but little is known about its mechanism. Working with mainstream smoke collected from commercial cigarettes we confirmed that cigarette smoke is a potent inhibitor of human MAO-A and -B isozymes. MAO inhibition was partly reversible, competitive for MAO-A, and a mixed-type inhibition for MAO-B. Two β-carboline alkaloids, norharman (β-carboline) and harman (1-methyl-β-carboline), were identified by GC-MS, quantified, and isolated from the mainstream smoke by solid phase extraction and HPLC. Kinetics analysis revealed that β-carbolines from cigarette smoke were competitive, reversible, and potent inhibitors of MAO enzymes. Norharman was an inhibitor of MAO-A (K i = 1.2 ± 0.18 μM) and MAO-B (K i = 1.12 ± 0.19 μM), and harman of MAO-A (K i = 55.54 ± 5.3 nM). β-Carboline alkaloids are psychopharmacologically active compounds that may occur endogenously in human tissues, including the brain. These results suggest that β-carboline alkaloids from cigarette smoke acting as potent reversible inhibitors of MAO enzymes may contribute to the MAO-reduced activity produced by tobacco smoke in smokers. The presence of MAO inhibitors in smoke like β-carbolines and others may help us to understand some of the purported neuropharmacological effects associated with smoking

Esters of Bendamustine Are by Far More Potent Cytotoxic Agents than the Parent Compound against Human Sarcoma and Carcinoma Cells.

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Stefan Huber

Full Text Available The alkylating agent bendamustine is approved for the treatment of hematopoietic malignancies such as non-Hodgkin lymphoma, chronic lymphocytic leukemia and multiple myeloma. As preliminary data on recently disclosed bendamustine esters suggested increased cytotoxicity, we investigated representative derivatives in more detail. Especially basic esters, which are positively charged under physiological conditions, were in the crystal violet and the MTT assay up to approximately 100 times more effective than bendamustine, paralleled by a higher fraction of early apoptotic cancer cells and increased expression of p53. Analytical studies performed with bendamustine and representative esters revealed pronounced cellular accumulation of the derivatives compared to the parent compound. In particular, the pyrrolidinoethyl ester showed a high enrichment in tumor cells and inhibition of OCT1- and OCT3-mediated transport processes, suggesting organic cation transporters to be involved. However, this hypothesis was not supported by the differential expression of OCT1 (SLC22A1 and OCT3 (SLC22A3, comparing a panel of human cancer cells. Bendamustine esters proved to be considerably more potent cytotoxic agents than the parent compound against a broad panel of human cancer cell types, including hematologic and solid malignancies (e.g. malignant melanoma, colorectal carcinoma and lung cancer, which are resistant to bendamustine. Interestingly, spontaneously immortalized human keratinocytes, as a model of "normal" cells, were by far less sensitive than tumor cells against the most potent bendamustine esters.

Vanadate monomers and dimers both inhibit the human prostatic acid phosphatase.

Science.gov (United States)

Crans, D C; Simone, C M; Saha, A K; Glew, R H

1989-11-30

A combination of enzyme kinetics and 51V NMR spectroscopy was used to identify the species of vanadate that inhibits acid phosphatases. Monomeric vanadate was shown to inhibit wheat germ and potato acid phosphatases. At pH 5.5, the vanadate dimer inhibits the human prostatic acid phosphatase whereas at pH 7.0 it is the vanadate monomer that inhibits this enzyme. The pH-dependent shift in the affinity of the prostatic phosphatase for vanadate is presumably due to deprotonation of an amino acid side chain in or near the binding site resulting in a conformational change in the protein. pH may be a subtle effector of the insulin-like vanadate activity in biological systems and may explain some of the differences in selectivity observed with the protein phosphatases.

Human mesenchymal stem cells inhibit osteoclastogenesis through osteoprotegerin production.

Science.gov (United States)

Oshita, Koichi; Yamaoka, Kunihiro; Udagawa, Nobuyuki; Fukuyo, Shunsuke; Sonomoto, Koshiro; Maeshima, Keisuke; Kurihara, Ryuji; Nakano, Kazuhisa; Saito, Kazuyoshi; Okada, Yosuke; Chiba, Kenji; Tanaka, Yoshiya

2011-06-01

Mesenchymal stem cells (MSCs) have been proposed to be a useful tool for treatment of rheumatoid arthritis (RA), not only because of their multipotency but also because of their immunosuppressive effect on lymphocytes, dendritic cells, and other proinflammatory cells. Since bone destruction caused by activated osteoclasts occurs in RA, we undertook the present study to investigate the effect of MSCs on osteoclast function and differentiation in order to evaluate their potential use in RA therapy. Human MSCs and peripheral blood mononuclear cells were cultured under cell-cell contact-free conditions with osteoclast induction medium. Differentiation into osteoclast-like cells was determined by tartrate-resistant acid phosphatase staining and expression of osteoclast differentiation markers. The number of osteoclast-like cells was decreased and expression of cathepsin K and nuclear factor of activated T cells c1 (NF-ATc1) was down-regulated by the addition of either MSCs or a conditioned medium obtained from MSCs. Osteoprotegerin (OPG) was constitutively produced by MSCs and inhibited osteoclastogenesis. However, osteoclast differentiation was not fully recovered upon treatment with either anti-OPG antibody or OPG small interfering RNA, suggesting that OPG had only a partial role in the inhibitory effect of MSCs. Moreover, bone-resorbing activity of osteoclast-like cells was partially recovered by addition of anti-OPG antibody into the conditioned medium. The present results indicate that human MSCs constitutively produce OPG, resulting in inhibition of osteoclastogenesis and expression of NF-ATc1 and cathepsin K in the absence of cell-cell contact. Therefore, we conclude that human MSCs exert a suppressive effect on osteoclastogenesis, which may be beneficial in inhibition of joint damage in RA. Copyright © 2011 by the American College of Rheumatology.

Antiviral activity of human lactoferrin: inhibition of alphavirus interaction with heparan sulfate

International Nuclear Information System (INIS)

Waarts, Barry-Lee; Aneke, Onwuchekwa J.C.; Smit, Jolanda M.; Kimata, Koji; Bittman, Robert; Meijer, Dirk K.F.; Wilschut, Jan

2005-01-01

Human lactoferrin is a component of the non-specific immune system with distinct antiviral properties. We used alphaviruses, adapted to interaction with heparan sulfate (HS), as a tool to investigate the mechanism of lactoferrin's antiviral activity. Lactoferrin inhibited infection of BHK-21 cells by HS-adapted, but not by non-adapted, Sindbis virus (SIN) or Semliki Forest virus (SFV). Lactoferrin also inhibited binding of radiolabeled HS-adapted viruses to BHK-21 cells or liposomes containing lipid-conjugated heparin as a receptor analog. On the other hand, low-pH-induced fusion of the viruses with liposomes, which occurs independently of virus-receptor interaction, was unaffected. Studies involving preincubation of virus or cells with lactoferrin suggested that the protein does not bind to the virus, but rather blocks HS-moieties on the cell surface. Charge-modified human serum albumin, with a net positive charge, had a similar antiviral effect against HS-adapted SIN and SFV, suggesting that the antiviral activity of lactoferrin is related to its positive charge. It is concluded that human lactoferrin inhibits viral infection by interfering with virus-receptor interaction rather than by affecting subsequent steps in the viral cell entry or replication processes

Inhibition of autophagy induced by proteasome inhibition increases cell death in human SHG-44 glioma cells.

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Ge, Peng-Fei; Zhang, Ji-Zhou; Wang, Xiao-Fei; Meng, Fan-Kai; Li, Wen-Chen; Luan, Yong-Xin; Ling, Feng; Luo, Yi-Nan

2009-07-01

The ubiquitin-proteasome system (UPS) and lysosome-dependent macroautophagy (autophagy) are two major intracellular pathways for protein degradation. Recent studies suggest that proteasome inhibitors may reduce tumor growth and activate autophagy. Due to the dual roles of autophagy in tumor cell survival and death, the effect of autophagy on the destiny of glioma cells remains unclear. In this study, we sought to investigate whether inhibition of the proteasome can induce autophagy and the effects of autophagy on the fate of human SHG-44 glioma cells. The proteasome inhibitor MG-132 was used to induce autophagy in SHG-44 glioma cells, and the effect of autophagy on the survival of SHG-44 glioma cells was investigated using an autophagy inhibitor 3-MA. Cell viability was measured by MTT assay. Apoptosis and cell cycle were detected by flow cytometry. The expression of autophagy related proteins was determined by Western blot. MG-132 inhibited cell proliferation, induced cell death and cell cycle arrest at G(2)/M phase, and activated autophagy in SHG-44 glioma cells. The expression of autophagy-related Beclin-1 and LC3-I was significantly up-regulated and part of LC3-I was converted into LC3-II. However, when SHG-44 glioma cells were co-treated with MG-132 and 3-MA, the cells became less viable, but cell death and cell numbers at G(2)/M phase increased. Moreover, the accumulation of acidic vesicular organelles was decreased, the expression of Beclin-1 and LC3 was significantly down-regulated and the conversion of LC3-II from LC3-I was also inhibited. Inhibition of the proteasome can induce autophagy in human SHG-44 glioma cells, and inhibition of autophagy increases cell death. This discovery may shed new light on the effect of autophagy on modulating the fate of SHG-44 glioma cells.Acta Pharmacologica Sinica (2009) 30: 1046-1052; doi: 10.1038/aps.2009.71.

Apoptosis induction in human lymphocytes after in vitro exposure to cobalt/hard metal compounds

International Nuclear Information System (INIS)

Boeck, M. de; Decordier, I.; Lombaert, N.; Cundari, E.; Kirsch-Volders, M.; Lison, D.

2001-01-01

Full text: An increased risk of lung cancer is associated with occupational exposure to mixtures of cobalt metal (Co) and tungsten carbide (WC) particles, but apparently not when exposure is to cobalt alone. The mechanism for this increased cancer risk is not fully understood. The evaluation of the in vitro genotoxic effects in lymphocytes exposed to varying cobalt species demonstrated that the WC-Co hard metal mixture is more genotoxic (DNA damage, chromosome/genome mutations) than metallic Co alone. WC alone was not genotoxic. Thus, WC-Co represents a specific (geno)toxic entity. In order to assess the survival of human lymphocytes after in vitro exposure to metallic Co, CoCl 2 , WC and the WC-Co mixture, two apoptosis/necrosis detection methods were applied (annexin V staining and flow cytometry). Annexin-V staining of early apoptotic cells demonstrated a dose- and time dependent induction of apoptosis by metallic Co, CoCl 2 , WC and the WC-Co mixture. The time course of the process varied according to the metal species tested. Metallic Co and CoCl 2 caused a gradually increasing frequency of apoptotic cells with time (up to 24 h). WC-induced apoptosis displayed a typical 6 hour peak, which was not the case for the WC-Co mixture or for Co. Apoptosis induction by the WC-Co mixture was intermediate between that induced by Co and WC separately. Analysis of propidium iodide stained cells by flow cytometry was performed as a later marker for apoptosis induction. Preliminary data indicate similar tendencies of apoptosis induction as those detected by annexin-V. Identification of the apoptotic pathway triggered by the metal compounds was studied by inhibition of the ceramide-apoptosis pathway by fumonisin causing reduction of apoptosis induction for all compounds, but strongest after 6 hour exposure to WC. The use of specific caspase inhibitors will allow to further elucidate the different pathways involved. The current data demonstrating in vitro the apoptosis

Apoptosis induction in human lymphocytes after in vitro exposure to cobalt/hard metal compounds

Energy Technology Data Exchange (ETDEWEB)

Boeck, M de; Decordier, I; Lombaert, N; Cundari, E; Kirsch-Volders, M [Vrije Universiteit Brussel, Laboratorium voor Cellulaire Genetica, Brussel (Belgium); Lison, D [Universite catholique de Louvain, Unite de Toxicologie industrielle et Medecine du Travail, Bruxelles (Belgium)

2001-07-01

Full text: An increased risk of lung cancer is associated with occupational exposure to mixtures of cobalt metal (Co) and tungsten carbide (WC) particles, but apparently not when exposure is to cobalt alone. The mechanism for this increased cancer risk is not fully understood. The evaluation of the in vitro genotoxic effects in lymphocytes exposed to varying cobalt species demonstrated that the WC-Co hard metal mixture is more genotoxic (DNA damage, chromosome/genome mutations) than metallic Co alone. WC alone was not genotoxic. Thus, WC-Co represents a specific (geno)toxic entity. In order to assess the survival of human lymphocytes after in vitro exposure to metallic Co, CoCl{sub 2}, WC and the WC-Co mixture, two apoptosis/necrosis detection methods were applied (annexin V staining and flow cytometry). Annexin-V staining of early apoptotic cells demonstrated a dose- and time dependent induction of apoptosis by metallic Co, CoCl{sub 2}, WC and the WC-Co mixture. The time course of the process varied according to the metal species tested. Metallic Co and CoCl{sub 2} caused a gradually increasing frequency of apoptotic cells with time (up to 24 h). WC-induced apoptosis displayed a typical 6 hour peak, which was not the case for the WC-Co mixture or for Co. Apoptosis induction by the WC-Co mixture was intermediate between that induced by Co and WC separately. Analysis of propidium iodide stained cells by flow cytometry was performed as a later marker for apoptosis induction. Preliminary data indicate similar tendencies of apoptosis induction as those detected by annexin-V. Identification of the apoptotic pathway triggered by the metal compounds was studied by inhibition of the ceramide-apoptosis pathway by fumonisin causing reduction of apoptosis induction for all compounds, but strongest after 6 hour exposure to WC. The use of specific caspase inhibitors will allow to further elucidate the different pathways involved. The current data demonstrating in vitro the

A small-molecule compound inhibits a collagen-specific molecular chaperone and could represent a potential remedy for fibrosis.

Science.gov (United States)

Ito, Shinya; Ogawa, Koji; Takeuchi, Koh; Takagi, Motoki; Yoshida, Masahito; Hirokawa, Takatsugu; Hirayama, Shoshiro; Shin-Ya, Kazuo; Shimada, Ichio; Doi, Takayuki; Goshima, Naoki; Natsume, Tohru; Nagata, Kazuhiro

2017-12-08

Fibrosis can disrupt tissue structure and integrity and impair organ function. Fibrosis is characterized by abnormal collagen accumulation in the extracellular matrix. Pharmacological inhibition of collagen secretion therefore represents a promising strategy for the management of fibrotic disorders, such as liver and lung fibrosis. Hsp47 is an endoplasmic reticulum (ER)-resident collagen-specific molecular chaperone essential for correct folding of procollagen in the ER. Genetic deletion of Hsp47 or inhibition of its interaction with procollagen interferes with procollagen triple helix production, which vastly reduces procollagen secretion from fibroblasts. Thus, Hsp47 could be a potential and promising target for the management of fibrosis. In this study, we screened small-molecule compounds that inhibit the interaction of Hsp47 with collagen from chemical libraries using surface plasmon resonance (BIAcore), and we found a molecule AK778 and its cleavage product Col003 competitively inhibited the interaction and caused the inhibition of collagen secretion by destabilizing the collagen triple helix. Structural information obtained with NMR analysis revealed that Col003 competitively binds to the collagen-binding site on Hsp47. We propose that these structural insights could provide a basis for designing more effective therapeutic drugs for managing fibrosis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Telomerase inhibition effectively targets mouse and human AML stem cells and delays relapse following chemotherapy

DEFF Research Database (Denmark)

Bruedigam, Claudia; Bagger, Frederik Otzen; Heidel, Florian H.

2014-01-01

(-/-) LSCs express a specific gene expression signature that can be identified in human AML patient cohorts and is positively correlated with patient survival following chemotherapy. In xenografts of primary human AML, genetic or pharmacological inhibition of telomerase targets LSCs, impairs leukemia...... progression, and delays relapse following chemotherapy. Altogether, these results establish telomerase inhibition as an effective strategy for eliminating AML LSCs....

A non-radiolabelled ferriprotoporphyrin IX biomineralisation inhibition test for the high throughput screening of antimalarial compounds.

Science.gov (United States)

Deharo, E; García, R N; Oporto, P; Gimenez, A; Sauvain, M; Jullian, V; Ginsburg, H

2002-04-01

Intraerythrocytic malaria parasites produce large amounts of toxic ferriprotoporphyrin IX (FP) during their digestion of host cell haemoglobin. The inhibition of biomineralisation of FP to haemozoin (or beta-haematin) by antimalarial drugs underlies their mode of action. We have developed an in vitro microassay for testing the inhibition of biomineralisation by drugs. It is based on the detection by optical density measurement of solubilised beta-haematin remaining after contact with drugs. The assay uses a 192-microM haemin chloride solution in dimethyl sulfoxide, 96-well filtration microplates as well as normal microplates; it lasts 18-24h and requires a spectrophotometer. We determined by this assay the IC(50) of chloroquine phosphate (28microM) and quinine base (324microM) and showed that unlike previous methods it is insensitive to inorganic anions. We also determined the activity of synthetic dyes and plant extract to determinate the interference of coloured compounds on the accuracy of the test. We found that methylene blue, thionine (IC(50) 38 and 87microM, respectively), and an extract of plants that contains quinoline derivatives, inhibited the biomineralisation of FP regardless of their intrinsic colour.

Dihydroartemisinin inhibits the human erythroid cell differentiation by altering the cell cycle

International Nuclear Information System (INIS)

Finaurini, Sara; Basilico, Nicoletta; Corbett, Yolanda; D’Alessandro, Sarah; Parapini, Silvia; Olliaro, Piero; Haynes, Richard K.; Taramelli, Donatella

2012-01-01

Artemisinin derivatives such as dihydroartemisinin (DHA) induce significant depletion of early embryonic erythroblasts in animal models. We have reported previously that DHA specifically targets pro-erythroblasts and basophilic erythroblasts, when human CD34+ stem cells are differentiated toward the erythroid lineage, indicating that a window of susceptibility to artemisinins may exist also in human developmental erythropoiesis during pregnancy. To better investigate the toxicity of artemisinin derivatives, the structure–activity relationship was evaluated against the K562 leukaemia cell line, used as a model for differentiating early human erythroblasts. All artemisinins derivatives, except deoxyartemisinin, inhibited both spontaneous and induced erythroid differentiation, confirming that the peroxide bridge is responsible for the erythro-toxicity. On the contrary, cell growth was markedly reduced by DHA, artemisone and artesunate but not by artemisinin, 10-deoxoartemisinin or deoxy-artemisinin. The substituent at position C-10 is responsible only for the anti-proliferative effect, since 10-deoxoartemisinin did not reduce cell growth but arrested the differentiation of K562 cells. In particular, the results showed that DHA resulted the most potent and rapidly acting compound of the drug family, causing (i) the decreased expression of GpA surface receptors and the down regulation the γ-globin gene; (ii) the alteration of S phase of cell cycle and (iii) the induction of programmed cell death of early erythroblasts in a dose dependent manner within 24 h. In conclusion, these findings confirm that the active metabolite DHA is responsible for the erythro-toxicity of most of artemisinins used in therapy. Thus, as long as no further clinical data are available, current WHO recommendations of avoiding malaria treatment with artemisinins during the first trimester of pregnancy remain valid.

Inhibition and reversal of nickel-induced transformation by the histone deacetylase inhibitor trichostatin A

International Nuclear Information System (INIS)

Zhang Qunwei; Salnikow, Konstantin; Kluz, Thomas; Chen, L.C.; Su, W.C.; Costa, Max

2003-01-01

The carcinogenic process initiated by nongenotoxic carcinogens involves modulation of gene expression. Nickel compounds have low mutagenic activity, but are highly carcinogenic. In vitro both mouse and human cells can be efficiently transformed by soluble and insoluble nickel compounds to anchorage-independent growth. Because previous studies have shown that carcinogenic nickel compounds silence genes by inhibiting histone acetylation and enhancing DNA methylation, we investigated the effect of enhancing histone acetylation on cell transformation. The exposure of nickel-transformed cells to the histone deacetylase inhibitor trichostatin A (TSA) resulted in the appearance of significant number of revertants measured by their inability to grow in soft agar. Using the Affymetrix GeneChip we found that the level of expression of a significant number of genes was changed (suppressed or upregulated) in nickel-transformed clones but returned to a normal level in revertants obtained following TSA treatment. Moreover, we found that treatment of cells with TSA inhibited the ability of nickel to transform mouse PW cells to anchorage-independent growth. Treatment with TSA also inhibited the ability of nickel to transform human HOS cells, although to a lesser extent. In contrast, treatment with TSA was not able to revert established cancer cell lines as readily as the nickel-transformed cells. These data indicated that modulation of gene expression is important for nickel-induced transformation

The selective estrogen receptor modulator raloxifene inhibits neutrophil extracellular trap formation.

Directory of Open Access Journals (Sweden)

Roxana Flores

2016-12-01

Full Text Available Raloxifene is a selective estrogen receptor modulator typically prescribed for the prevention/treatment of osteoporosis in postmenopausal women. Although raloxifene is known to have anti-inflammatory properties, its effect on human neutrophils, the primary phagocytic leukocytes of the immune system, remain poorly understood. Here, through a screen of pharmacologically active small molecules, we find that raloxifene prevents neutrophil cell death in response to the classical activator phorbol 12-myristate 13-acetate (PMA, a compound known to induce formation of DNA-based neutrophil extracellular traps (NETs. Inhibition of PMA-induced NET production by raloxifene was confirmed using quantitative and imaging-based assays. Human neutrophils from both male and female donors express the nuclear estrogen receptors ERα and ERβ, known targets of raloxifene. Like raloxifene, selective antagonists of these receptors inhibit PMA-induced NET production. Furthermore, raloxifene inhibited PMA-induced ERK phosphorylation but not reactive oxygen species (ROS production, pathways known to be key modulators of NET production. Finally, we found that raloxifene inhibited PMA-induced, NET-based killing of the leading human bacterial pathogen, methicillin-resistant Staphylococcus aureus (MRSA. Our results reveal that raloxifene is a potent modulator of neutrophil function and NET production.

Ginger Phytochemicals Inhibit Cell Growth and Modulate Drug Resistance Factors in Docetaxel Resistant Prostate Cancer Cell.

Science.gov (United States)

Liu, Chi-Ming; Kao, Chiu-Li; Tseng, Yu-Ting; Lo, Yi-Ching; Chen, Chung-Yi

2017-09-05

Ginger has many bioactive compounds with pharmacological activities. However, few studies are known about these bioactive compounds activity in chemoresistant cells. The aim of the present study was to investigate the anticancer properties of ginger phytochemicals in docetaxel-resistant human prostate cancer cells in vitro. In this study, we isolated 6-gingerol, 10-gingerol, 4-shogaol, 6-shogaol, 10-shogaol, and 6-dehydrogingerdione from ginger. Further, the antiproliferation activity of these compounds was examined in docetaxel-resistant (PC3R) and sensitive (PC3) human prostate cancer cell lines. 6-gingerol, 10-gingerol, 6-shogaol, and 10-shogaol at the concentration of 100 μM significantly inhibited the proliferation in PC3R but 6-gingerol, 6-shogaol, and 10-shogaol displayed similar activity in PC3. The protein expression of multidrug resistance associated protein 1 (MRP1) and glutathione-S-transferase (GSTπ) is higher in PC3R than in PC3. In summary, we isolated the bioactive compounds from ginger. Our results showed that 6-gingerol, 10-gingerol, 6-shogaol, and 10-shogaol inhibit the proliferation of PC3R cells through the downregulation of MRP1 and GSTπ protein expression.

Potent inhibition of cytochrome P450 2B6 by sibutramine in human liver microsomes.

Science.gov (United States)

Bae, Soo Hyeon; Kwon, Min Jo; Choi, Eu Jin; Zheng, Yu Fen; Yoon, Kee Dong; Liu, Kwang-Hyeon; Bae, Soo Kyung

2013-09-05

The present study was performed to evaluate the potency and specificity of sibutramine as an inhibitor of the activities of nine human CYP isoforms in liver microsomes. Using a cocktail assay, the effects of sibutramine on specific marker reactions of the nine CYP isoforms were measured in human liver microsomes. Sibutramine showed potent inhibition of CYP2B6-mediated bupropion 6-hydroxylation with an IC50 value of 1.61μM and Ki value of 0.466μM in a competitive manner at microsomal protein concentrations of 0.25mg/ml; this was 3.49-fold more potent than the typical CYP2B6 inhibitor thio-TEPA (Ki=1.59μM). In addition, sibutramine slightly inhibited CYP2C19 activity (Ki=16.6μM, noncompetitive inhibition) and CYP2D6 activity (Ki=15.7μM, noncompetitive inhibition). These observations indicated 35.6- and 33.7-fold decreases in inhibition potency, respectively, compared with that of CYP2B6 by sibutramine. However, no inhibition of CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2D6, or CYP2E1 activities was observed. In addition, the CYP2B6 inhibitory potential of sibutramine was enhanced at a lower microsomal protein concentration of 0.05mg/ml. After 30min preincubation of human liver microsomes with sibutramine in the presence of NADPH, no shift in IC50 was observed in terms of inhibition of the activities of the nine CYPs, suggesting that sibutramine is not a time-dependent inactivator. These observations suggest that sibutramine is a selective and potent inhibitor of CYP2B6 in vitro, whereas inhibition of other CYPs is substantially lower. These in vitro data support the use of sibutramine as a well-known inhibitor of CYP2B6 for routine screening of P450 reversible inhibition when human liver microsomes are used as the enzyme source. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

PPARγ ligand ciglitazone inhibits TNFα-induced ICAM-1 in human airway smooth muscle cells

Directory of Open Access Journals (Sweden)

Chien-Da Huang

2014-08-01

Full Text Available Background: Modification of human airway smooth muscle (ASM function by proinflammatory cytokines has been regarded as a potential mechanism underlying bronchial hyperresponsiveness in asthma. Human ASM cells express intercellular adhesion molecule (ICAM-1 in response to cytokines. Synthetic ligands for peroxisome proliferator-activated receptor (PPARγ reportedly possess anti-inflammatory and immunomodulatory properties. In this study, we examined whether ciglitazone, a synthetic PPARγ ligand, can modulate the basal and tumor necrosis factor (TNFα-induced ICAM1 gene expression in human ASM cells. Methods: Human ASM cells were treated with TNFα. ICAM-1 expression was assessed by flow cytometry and reverse transcriptase-polymerase chain reaction (RT-PCR analysis. PPARγ activity was inhibited by target-specific small interfering (si RNA targeting PPARγ and GW9662, a PPARγ antagonist. Activity of nuclear factor (NF-κB was assessed by using immunoblot analysis, immune-confocal images, and electrophoretic mobility shift assay (EMSA. Results: By flow cytometry, ciglitazone alone had no effect on ICAM-1 expression in ASM cells, but inhibited ICAM-1 expression in response to TNFα (10 ng/ml in a dose-dependent manner (1-10 μM. It also inhibited TNFα-induced ICAM1 gene expression by RT-PCR analysis. Knockdown of PPARγ gene by target-specific siRNA targeting PPARγ enhanced ICAM-1 expression and the inhibitory effect of ciglitazone on TNFα-induced ICAM-1 expression was reversed by PPARγ siRNA and GW9662. SN-50 (10 μg/ml, an inhibitor for nuclear translocation of NF-κB, inhibited TNFα-induced ICAM-1 expression. Ciglitazone did not prevent TNFα-induced degradation of the cytosolic inhibitor of NF-κB (IκB, but inhibited the nuclear translocation of p65 induced by TNFα and suppressed the NF-κB/DNA binding activity. Conclusion: These findings suggest that ciglitazone inhibits TNFα-induced ICAM1 gene expression in human ASM cells through

Malaria parasite carbonic anhydrase: inhibition of aromatic/heterocyclic sulfonamides and its therapeutic potential

Science.gov (United States)

Krungkrai, Sudaratana R; Krungkrai, Jerapan

2011-01-01

Plasmodium falciparum (P. falciparum) is responsible for the majority of life-threatening cases of human malaria, causing 1.5-2.7 million annual deaths. The global emergence of drug-resistant malaria parasites necessitates identification and characterization of novel drug targets and their potential inhibitors. We identified the carbonic anhydrase (CA) genes in P. falciparum. The pfCA gene encodes anα-carbonic anhydrase, a Zn2+-metalloenzme, possessing catalytic properties distinct from that of the human host CA enzyme. The amino acid sequence of the pfCA enzyme is different from the analogous protozoan and human enzymes. A library of aromatic/heterocyclic sulfonamides possessing a large diversity of scaffolds were found to be very good inhibitors for the malarial enzyme at moderate-low micromolar and submicromolar inhibitions. The structure of the groups substituting the aromatic-ureido- or aromatic-azomethine fragment of the molecule and the length of the parent sulfonamide were critical parameters for the inhibitory properties of the sulfonamides. One derivative, that is, 4- (3, 4-dichlorophenylureido)thioureido-benzenesulfonamide (compound 10) was the most effective in vitro Plasmodium falciparum CA inhibitor, and was also the most effective antimalarial compound on the in vitro P. falciparum growth inhibition. The compound 10 was also effective in vivo antimalarial agent in mice infected with Plasmodium berghei, an animal model of drug testing for human malaria infection. It is therefore concluded that the sulphonamide inhibitors targeting the parasite CA may have potential for the development of novel therapies against human malaria. PMID:23569766

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

Energy Technology Data Exchange (ETDEWEB)

Jan, Yi-Hua [Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ (United States); Richardson, Jason R., E-mail: jricha3@eohsi.rutgers.edu [Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ (United States); Baker, Angela A. [Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ (United States); Mishin, Vladimir [Department of Pharmacology and Toxicology, Rutgers University, Piscataway, NJ (United States); Heck, Diane E. [Department of Environmental Health Science, New York Medical College, Valhalla, NY (United States); Laskin, Debra L. [Department of Pharmacology and Toxicology, Rutgers University, Piscataway, NJ (United States); Laskin, Jeffrey D., E-mail: jlaskin@eohsi.rutgers.edu [Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ (United States)

2015-10-01

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.

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.

Prolyl oligopeptidase inhibition-induced growth arrest of human gastric cancer cells

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Kanayo [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Sakaguchi, Minoru, E-mail: sakaguti@gly.oups.ac.jp [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Tanaka, Satoshi [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Yoshimoto, Tadashi [Department of Life Science, Setsunan University, 17-8 Ikeda-Nakamachi, Neyagawa, Osaka 572-8508 (Japan); Takaoka, Masanori [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan)

2014-01-03

Highlights: •We examined the effects of prolyl oligopeptidase (POP) inhibition on p53 null gastric cancer cell growth. •POP inhibition-induced cell growth suppression was associated with an increase in a quiescent G{sub 0} state. •POP might regulate the exit from and/or reentry into the cell cycle. -- Abstract: Prolyl oligopeptidase (POP) is a serine endopeptidase that hydrolyzes post-proline peptide bonds in peptides that are <30 amino acids in length. We recently reported that POP inhibition suppressed the growth of human neuroblastoma cells. The growth suppression was associated with pronounced G{sub 0}/G{sub 1} cell cycle arrest and increased levels of the CDK inhibitor p27{sup kip1} and the tumor suppressor p53. In this study, we investigated the mechanism of POP inhibition-induced cell growth arrest using a human gastric cancer cell line, KATO III cells, which had a p53 gene deletion. POP specific inhibitors, 3-((4-[2-(E)-styrylphenoxy]butanoyl)-L-4-hydroxyprolyl)-thiazolidine (SUAM-14746) and benzyloxycarbonyl-thioprolyl-thioprolinal, or RNAi-mediated POP knockdown inhibited the growth of KATO III cells irrespective of their p53 status. SUAM-14746-induced growth inhibition was associated with G{sub 0}/G{sub 1} cell cycle phase arrest and increased levels of p27{sup kip1} in the nuclei and the pRb2/p130 protein expression. Moreover, SUAM-14746-mediated cell cycle arrest of KATO III cells was associated with an increase in the quiescent G{sub 0} state, defined by low level staining for the proliferation marker, Ki-67. These results indicate that POP may be a positive regulator of cell cycle progression by regulating the exit from and/or reentry into the cell cycle by KATO III cells.

Organobromine compound profiling in human adipose: Assessment of sources of bromophenol

International Nuclear Information System (INIS)

Gao, Shixiong; Wan, Yi; Zheng, Guomao; Luo, Kai; Kannan, Kurunthachalam; Giesy, John P.; Lam, Michael H.W.; Hu, Jianying

2015-01-01

Bromophenols (BRPs) have been widely detected in human tissues, however, relative proportions from natural products and/or anthropogenic flame retardants are not clear. 21 polybrominated diphenyl ethers (PBDEs), 15 MeO/OH-PBDEs, and 10 BRPs were simultaneously quantified in adipose collected from people from New York City, USA. An in vitro assay utilizing human liver microsomes was performed for detected predominant organobromine. High concentrations of 2,4,6-triBRP and PBDEs were observed, and extremely low concentrations of naturally occurring MeO/OH-PBDEs were detected. Similar biotransformatioin rates of BRPs and MeO/OH-PBDEs indicated that the relative high concentration of 2,4,6-triBRP in humans was not of natural origin. Significant correlation observed between concentrations of 2,4,6-triBRP and BDE-209 suggested that the two chemicals may share a common source. Both 2,4,6-triBRP and BDE-209 were detected in commercial ABS resins, suggesting that plastic products made from ABS resins could be potential sources of co-exposure of the two compounds for humans. - Highlights: • 2,4,6-triBRP detected with high concentrations in human was not of natural origin. • Co-exposure of 2,4,6-triBRP and BDE-209 was observed in human samples. • Products made from ABS resins were potential exposure sources of 2,4,6-triBRP. - The profile of organobromine compounds in human together with biotransformation behaviors indicate that anthropogenic sources mainly contribute to high levels of bromophenols in humans

A broad range quorum sensing inhibitor working through sRNA inhibition

DEFF Research Database (Denmark)

Jakobsen, Tim H.; Warming, Anders N.; Vejborg, Rebecca M.

2017-01-01

that the repressing effect of ajoene on quorum sensing occurs by inhibition of small regulatory RNAs (sRNA) in P. aeruginosa as well as in Staphylococcus aureus, another important human pathogen that employs quorum sensing to control virulence gene expression. Using various reporter constructs, we found that ajoene......-spectrum compounds transcending the Gram negative-positive borderline....

Evaluation of a Silicone Membrane as an Alternative to Human Skin for Determining Skin Permeation Parameters of Chemical Compounds.

Science.gov (United States)

Uchida, Takashi; Yakumaru, Masafumi; Nishioka, Keisuke; Higashi, Yoshihiro; Sano, Tomohiko; Todo, Hiroaki; Sugibayashi, Kenji

2016-01-01

We evaluated the effectiveness of a silicone membrane as an alternative to human skin using the skin permeation parameters of chemical compounds. An in vitro permeation study using 15 model compounds was conducted, and permeation parameters comprising permeability coefficient (P), diffusion parameter (DL(-2)), and partition parameter (KL) were calculated from each permeation profile. Significant correlations were obtained in log P, log DL(-2), and log KL values between the silicone membrane and human skin. DL(-2) values of model compounds, except flurbiprofen, in the silicone membrane were independent of the lipophilicity of the model compounds and were 100-fold higher than those in human skin. For antipyrine and caffeine, which are hydrophilic, KL values in the silicone membrane were 100-fold lower than those in human skin, and P values, calculated as the product of a DL(-2) and KL, were similar. For lipophilic compounds, such as n-butyl paraben and flurbiprofen, KL values for silicone were similar to or 10-fold higher than those in human skin, and P values for silicone were 100-fold higher than those in human skin. Furthermore, for amphiphilic compounds with log Ko/w values from 0.5 to 3.5, KL values in the silicone membrane were 10-fold lower than those in human skin, and P values for silicone were 10-fold higher than those in human skin. The silicone membrane was useful as a human skin alternative in an in vitro skin permeation study. However, depending on the lipophilicity of the model compounds, some parameters may be over- or underestimated.

Oblongifolin M, an active compound isolated from a Chinese medical herb Garcinia oblongifolia, potently inhibits enterovirus 71 reproduction through downregulation of ERp57.

Science.gov (United States)

Wang, Mengjie; Dong, Qi; Wang, Hua; He, Yaqing; Chen, Ying; Zhang, Hong; Wu, Rong; Chen, Xinchun; Zhou, Boping; He, Jason; Kung, Hsiang-Fu; Huang, Canhua; Wei, Yuquan; Huang, Jian-dong; Xu, Hongxi; He, Ming-Liang

2016-02-23

There is no effective drug to treat EV71 infection yet. Traditional Chinese herbs are great resources for novel antiviral compounds. Here we showed that Oblongifolin M (OM), an active compound isolated from Garcinia oblongifolia, potently inhibited EV71 infection in a dose dependent manner. To identify its potential effectors in the host cells, we successfully identified 18 proteins from 52 differentially expressed spots by comparative proteomics studies. Further studies showed that knockdown of ERp57 inhibited viral replication through downregulating viral IRES (internal ribosome entry site) activities, whereas ectopic expression of ERp57 increased IRES activity and partly rescued the inhibitory effects of OM on viral replication. We demonstrated that OM is an effective antiviral agent; and that ERp57 is one of its cellular effectors against EV71 infection.

CTRP6 inhibits fibrogenesis in TGF-β1-stimulated human dermal fibroblasts

Energy Technology Data Exchange (ETDEWEB)

Fan, Rong-hui, E-mail: fan_ronghuixa@163.com [Department of Burn and Plastic Surgery, Shaanxi Provincial People’s Hospital, Xi’an 710068 (China); Zhu, Xiu-mei; Sun, Yao-wen [Department of Burn and Plastic Surgery, Shaanxi Provincial People’s Hospital, Xi’an 710068 (China); Peng, Hui-zi [Department of Cosmetology Plastic Surgery, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710061 (China); Wu, Hang-li; Gao, Wen-jie [Department of Burn and Plastic Surgery, Shaanxi Provincial People’s Hospital, Xi’an 710068 (China)

2016-07-08

Skin fibrosis is characterized by excessive proliferation of fibroblasts and overproduction of extracellular matrix (ECM). C1q/tumor necrosis factor-related protein 6 (CTRP6), a member of CTRPs, has been involved in the development of cardiac fibrosis. However, the function and detailed regulatory mechanism of CTRP6 in skin fibrosis remain unclear. The aim of this study was to investigate the effect of CTRP6 on the activation of human dermal fibroblasts. Our results showed that CTRP6 was lowly expressed in scar tissues and transforming growth factor-β1 (TGF-β1)-treated dermal fibroblasts. CTRP6 overexpression significantly inhibited the proliferation of dermal fibroblasts, as well as suppressed the expression of ECM in TGF-β1-treated dermal fibroblasts. Furthermore, CTRP6 overexpression markedly inhibited TGF-β1-induced phosphorylation of Smad3 in dermal fibroblasts. In conclusion, the data reported here demonstrate that CTRP6 is able to inhibit the proliferation and ECM expression in human dermal fibroblasts through suppressing the TGF-β1/Smad3 signaling pathway. These findings suggest that CTRP6 may be a potential therapeutic target for the prevention of skin fibrosis. -- Highlights: •CTRP6 expression was decreased in scar tissues and TGF-β1-treated dermal fibroblasts. •CTRP6 inhibits TGF-β1-induced the proliferation of dermal fibroblasts. •CTRP6 inhibits expression of collagen type I and α-SMA. •CTRP6 inhibits the activation of TGF-β1/Smad3 signaling pathway in dermal fibroblasts.

CTRP6 inhibits fibrogenesis in TGF-β1-stimulated human dermal fibroblasts

International Nuclear Information System (INIS)

Fan, Rong-hui; Zhu, Xiu-mei; Sun, Yao-wen; Peng, Hui-zi; Wu, Hang-li; Gao, Wen-jie

2016-01-01

Skin fibrosis is characterized by excessive proliferation of fibroblasts and overproduction of extracellular matrix (ECM). C1q/tumor necrosis factor-related protein 6 (CTRP6), a member of CTRPs, has been involved in the development of cardiac fibrosis. However, the function and detailed regulatory mechanism of CTRP6 in skin fibrosis remain unclear. The aim of this study was to investigate the effect of CTRP6 on the activation of human dermal fibroblasts. Our results showed that CTRP6 was lowly expressed in scar tissues and transforming growth factor-β1 (TGF-β1)-treated dermal fibroblasts. CTRP6 overexpression significantly inhibited the proliferation of dermal fibroblasts, as well as suppressed the expression of ECM in TGF-β1-treated dermal fibroblasts. Furthermore, CTRP6 overexpression markedly inhibited TGF-β1-induced phosphorylation of Smad3 in dermal fibroblasts. In conclusion, the data reported here demonstrate that CTRP6 is able to inhibit the proliferation and ECM expression in human dermal fibroblasts through suppressing the TGF-β1/Smad3 signaling pathway. These findings suggest that CTRP6 may be a potential therapeutic target for the prevention of skin fibrosis. -- Highlights: •CTRP6 expression was decreased in scar tissues and TGF-β1-treated dermal fibroblasts. •CTRP6 inhibits TGF-β1-induced the proliferation of dermal fibroblasts. •CTRP6 inhibits expression of collagen type I and α-SMA. •CTRP6 inhibits the activation of TGF-β1/Smad3 signaling pathway in dermal fibroblasts.

Acute effects of cocaine and cannabis on response inhibition in humans: an ERP investigation

NARCIS (Netherlands)

Spronk, D.B.; De Bruijn, E.R.; van Wel, J.H.; Ramaekers, J.G.; Verkes, R.J.

2016-01-01

Substance abuse has often been associated with alterations in response inhibition in humans. Not much research has examined how the acute effects of drugs modify the neurophysiological correlates of response inhibition, or how these effects interact with individual variation in trait levels of

Cellobiose Dehydrogenase Inhibition of Polymerization of Phenolic Compounds and Enhancing Lignin Degradation by Lignina.

Science.gov (United States)

Fang, Jing; Liu, Wen; Gao, Pei-Ji

1999-01-01

The kinetic behavior of cellobiose dehydrogenase (CDH) was investigated by steady-state initial velocity studies. Variation in the concentration of one substrate led to changes in K(m) and V(max) of the other substrate. The results were consistent with a ping-pong mechanism. In the presence of cellobiose, CDH could reduce many oxidized products catalyzed by soybean hull peroxidase (SHP). The oxidation product of 1-hydroxybenzotriazole (HBT) catalyzed by SHP inactivated the enzyme itself however, CDH could prevent SHP from inactivation by reducing the oxidation product of HBT. CDH could also inhibit the polymerization of phenolic compounds catalyzed by SHP. It was found that the addition of CDH could enhance kraft pulp lignin degradation by ligninases.

Cardiac glycosides induce cell death in human cells by inhibiting general protein synthesis.

Directory of Open Access Journals (Sweden)

Andrea Perne

2009-12-01

Full Text Available Cardiac glycosides are Na(+/K(+-pump inhibitors widely used to treat heart failure. They are also highly cytotoxic, and studies have suggested specific anti-tumor activity leading to current clinical trials in cancer patients. However, a definitive demonstration of this putative anti-cancer activity and the underlying molecular mechanism has remained elusive.Using an unbiased transcriptomics approach, we found that cardiac glycosides inhibit general protein synthesis. Protein synthesis inhibition and cytotoxicity were not specific for cancer cells as they were observed in both primary and cancer cell lines. These effects were dependent on the Na(+/K(+-pump as they were rescued by expression of a cardiac glycoside-resistant Na(+/K(+-pump. Unlike human cells, rodent cells are largely resistant to cardiac glycosides in vitro and mice were found to tolerate extremely high levels.The physiological difference between human and mouse explains the previously observed sensitivity of human cancer cells in mouse xenograft experiments. Thus, published mouse xenograft models used to support anti-tumor activity for these drugs require reevaluation. Our finding that cardiac glycosides inhibit protein synthesis provides a mechanism for the cytotoxicity of CGs and raises concerns about ongoing clinical trials to test CGs as anti-cancer agents in humans.

The monoamine oxidase inhibition properties of selected structural analogues of methylene blue

International Nuclear Information System (INIS)

Delport, Anzelle; Harvey, Brian H.; Petzer, Anél; Petzer, Jacobus P.

2017-01-01

The thionine dye, methylene blue (MB), is a potent inhibitor of monoamine oxidase (MAO) A, a property that may, at least in part, mediate its antidepressant effects in humans and animals. The central inhibition of MAO-A by MB has also been linked to serotonin toxicity (ST) which may arise when MB is used in combination with serotonergic drugs. Structural analogues and the principal metabolite of MB, azure B, have also been reported to inhibit the MAO enzymes, with all compounds exhibiting specificity for the MAO-A isoform. To expand on the structure-activity relationships (SARs) of MAO inhibition by MB analogues, the present study investigates the human MAO inhibition properties of five MB analogues: neutral red, Nile blue, new methylene blue, cresyl violet and 1,9-dimethyl methylene blue. Similar to MB, these analogues also are specific MAO-A inhibitors with cresyl violet (IC 50 = 0.0037 μM), Nile blue (IC 50 = 0.0077 μM) and 1,9-dimethyl methylene blue (IC 50 = 0.018 μM) exhibiting higher potency inhibition compared to MB (IC 50 = 0.07 μM). Nile blue also represents a potent MAO-B inhibitor with an IC 50 value of 0.012 μM. From the results it may be concluded that non-thionine MB analogues (e.g. cresyl violet and Nile blue) also may exhibit potent MAO inhibition, a property which should be considered when using these compounds in pharmacological studies. Benzophenoxazines such as cresyl violet and Nile blue are, similar to phenothiazines (e.g. MB), representative of high potency MAO-A inhibitors with a potential risk of ST. - Highlights: • MB analogues, cresyl violet and Nile blue, are high potency MAO-A inhibitors. • Nile blue also represents a potent MAO-B inhibitor. • Potent MAO-A inhibition should alert to potential serotonin toxicity.

The monoamine oxidase inhibition properties of selected structural analogues of methylene blue

Energy Technology Data Exchange (ETDEWEB)

Delport, Anzelle [Pharmaceutical Chemistry, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Centre of Excellence for Pharmaceutical Sciences, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Harvey, Brian H. [Centre of Excellence for Pharmaceutical Sciences, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Pharmacology, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Petzer, Anél [Pharmaceutical Chemistry, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Centre of Excellence for Pharmaceutical Sciences, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Petzer, Jacobus P., E-mail: jacques.petzer@nwu.ac.za [Pharmaceutical Chemistry, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Centre of Excellence for Pharmaceutical Sciences, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa)

2017-06-15

The thionine dye, methylene blue (MB), is a potent inhibitor of monoamine oxidase (MAO) A, a property that may, at least in part, mediate its antidepressant effects in humans and animals. The central inhibition of MAO-A by MB has also been linked to serotonin toxicity (ST) which may arise when MB is used in combination with serotonergic drugs. Structural analogues and the principal metabolite of MB, azure B, have also been reported to inhibit the MAO enzymes, with all compounds exhibiting specificity for the MAO-A isoform. To expand on the structure-activity relationships (SARs) of MAO inhibition by MB analogues, the present study investigates the human MAO inhibition properties of five MB analogues: neutral red, Nile blue, new methylene blue, cresyl violet and 1,9-dimethyl methylene blue. Similar to MB, these analogues also are specific MAO-A inhibitors with cresyl violet (IC{sub 50} = 0.0037 μM), Nile blue (IC{sub 50} = 0.0077 μM) and 1,9-dimethyl methylene blue (IC{sub 50} = 0.018 μM) exhibiting higher potency inhibition compared to MB (IC{sub 50} = 0.07 μM). Nile blue also represents a potent MAO-B inhibitor with an IC{sub 50} value of 0.012 μM. From the results it may be concluded that non-thionine MB analogues (e.g. cresyl violet and Nile blue) also may exhibit potent MAO inhibition, a property which should be considered when using these compounds in pharmacological studies. Benzophenoxazines such as cresyl violet and Nile blue are, similar to phenothiazines (e.g. MB), representative of high potency MAO-A inhibitors with a potential risk of ST. - Highlights: • MB analogues, cresyl violet and Nile blue, are high potency MAO-A inhibitors. • Nile blue also represents a potent MAO-B inhibitor. • Potent MAO-A inhibition should alert to potential serotonin toxicity.

Quorum sensing inhibition

DEFF Research Database (Denmark)

Persson, T.; Givskov, Michael Christian; Nielsen, J.

2005-01-01

/receptor transcriptional regulator in some clinically relevant Gram-negative bacteria. The present review contains all reported compound types that are currently known to inhibit the QS transcriptional regulator in Gram-negative bacteria. These compounds are sub-divided into two main groups, one comprising structural...

Baicalein inhibits the migration and invasive properties of human hepatoma cells

International Nuclear Information System (INIS)

Chiu, Yung-Wei; Lin, Tseng-Hsi; Huang, Wen-Shih; Teng, Chun-Yuh; Liou, Yi-Sheng; Kuo, Wu-Hsien; Lin, Wea-Lung; Huang, Hai-I; Tung, Jai-Nien; Huang, Chih-Yang; Liu, Jer-Yuh; Wang, Wen-Hung; Hwang, Jin-Ming

2011-01-01

Flavonoids have been demonstrated to exert health benefits in humans. We investigated whether the flavonoid baicalein would inhibit the adhesion, migration, invasion, and growth of human hepatoma cell lines, and we also investigated its mechanism of action. The separate effects of baicalein and baicalin on the viability of HA22T/VGH and SK-Hep1 cells were investigated for 24 h. To evaluate their invasive properties, cells were incubated on matrigel-coated transwell membranes in the presence or absence of baicalein. We examined the effect of baicalein on the adhesion of cells, on the activation of matrix metalloproteinases (MMPs), protein kinase C (PKC), and p38 mitogen-activated protein kinase (MAPK), and on tumor growth in vivo. We observed that baicalein suppresses hepatoma cell growth by 55%, baicalein-treated cells showed lower levels of migration than untreated cells, and cell invasion was significantly reduced to 28%. Incubation of hepatoma cells with baicalein also significantly inhibited cell adhesion to matrigel, collagen I, and gelatin-coated substrate. Baicalein also decreased the gelatinolytic activities of the matrix metalloproteinases MMP-2, MMP-9, and uPA, decreased p50 and p65 nuclear translocation, and decreased phosphorylated I-kappa-B (IKB)-β. In addition, baicalein reduced the phosphorylation levels of PKCα and p38 proteins, which regulate invasion in poorly differentiated hepatoma cells. Finally, when SK-Hep1 cells were grown as xenografts in nude mice, intraperitoneal (i.p.) injection of baicalein induced a significant dose-dependent decrease in tumor growth. These results demonstrate the anticancer properties of baicalein, which include the inhibition of adhesion, invasion, migration, and proliferation of human hepatoma cells in vivo. - Highlight: → Baicalein inhibits several essential steps in the onset of metastasis.

Human transbodies to VP40 inhibit cellular egress of Ebola virus-like particles

International Nuclear Information System (INIS)

Teimoori, Salma; Seesuay, Watee; Jittavisutthikul, Surasak; Chaisri, Urai; Sookrung, Nitat; Densumite, Jaslan; Saelim, Nawannaporn; Chulanetra, Monrat; Maneewatch, Santi; Chaicumpa, Wanpen

2016-01-01

A direct acting anti-Ebola agent is needed. VP40, a conserved protein across Ebolavirus (EBOV) species has several pivotal roles in the virus life cycle. Inhibition of VP40 functions would lessen the virion integrity and interfere with the viral assembly, budding, and spread. In this study, cell penetrable human scFvs (HuscFvs) that bound to EBOV VP40 were produced by phage display technology. Gene sequences coding for VP40-bound-HuscFvs were subcloned from phagemids into protein expression plasmids downstream to a gene of cell penetrating peptide, i.e., nonaarginine (R9). By electron microscopy, transbodies from three clones effectively inhibited egress of the Ebola virus-like particles from human hepatic cells transduced with pseudo-typed-Lentivirus particles carrying EBOV VP40 and GP genes. Computerized simulation indicated that the effective HuscFvs bound to multiple basic residues in the cationic patch of VP40 C-terminal domain which are important in membrane-binding for viral matrix assembly and virus budding. The transbodies bound also to VP40 N-terminal domain and L domain peptide encompassed the PTAPPEY (WW binding) motif, suggesting that they might confer VP40 function inhibition through additional mechanism(s). The generated transbodies are worthwhile tested with authentic EBOV before developing to direct acting anti-Ebola agent for preclinical and clinical trials. - Highlights: • Cell penetrable human scFvs (transbodies) to Ebolavirus (EBOV) VP40 were produced. • The transbodies inhibited egress of EBOV-like particles (VLPs) from human hepatocytes. • They interacted with VP40 CTD basic residues important for plasma membrane binding. • And hence interfere with viral matrix assembly and viral progeny budding. • This is the first report on human antibodies that target intracellular EBOV VP40.

Inhibition of endogenous lactate turnover with lactate infusion in humans

International Nuclear Information System (INIS)

Searle, G.L.; Feingold, K.R.; Hsu, F.S.; Clark, O.H.; Gertz, E.W.; Stanley, W.C.

1989-01-01

The extent to which lactate infusion may inhibit endogenous lactate production, though previously considered, has never been critically assessed. To examine this proposition, single injection tracer methodology (U- 14 C Lactate) has been used for the estimation of lactate kinetics in 12 human subjects under basal conditions and with the infusion of sodium lactate. The basal rate of lactate turnover was measured on a day before the study with lactate infusion, and averaged 63.7 + 5.5 mg/kg/h. Six of these individuals received a stable lactate infusion at an approximate rate of 160 mg/kg/h, while the remaining six individuals were infused at the approximate rate of 100 mg/kg/h. It has been found that stable lactate infused at rates approximating 160 mg/kg/h consistently produced a complete inhibition of endogenous lactate production. Infusion of lactate at 100 mg/kg/h caused a lesser and more variable inhibition of endogenous lactate production (12% to 64%). In conclusion, lactate infusion significantly inhibits endogenous lactate production

Inhibitory effects of black pepper (Piper nigrum) extracts and compounds on human tumor cell proliferation, cyclooxygenase enzymes, lipid peroxidation and nuclear transcription factor-kappa-B.

Science.gov (United States)

Liu, Yunbao; Yadev, Vivek R; Aggarwal, Bharat B; Nair, Muraleedharan G

2010-08-01

Black pepper (Piper nigrum) and hot pepper (Capsicum spp.) are widely used in traditional medicines. Although hot Capsicum spp. extracts and its active principles, capsaicinoids, have been linked with anticancer and anti-inflammatory activities, whether black pepper and its active principle exhibit similar activities is not known. In this study, we have evaluated the antioxidant, anti-inflammatory and anticancer activities of extracts and compounds from black pepper by using proinflammatory transcription factor NF-kappaB, COX-1 and -2 enzymes, human tumor cell proliferation and lipid peroxidation (LPO). The capsaicinoids, the alkylamides, isolated from the hot pepper Scotch Bonnet were also used to compare the bioactivities of alkylamides and piperine from black pepper. All compounds derived from black pepper suppressed TNF-induced NF-kappaB activation, but alkyl amides, compound 4 from black pepper and 5 from hot pepper, were most effective. The human cancer cell proliferation inhibitory activities of piperine and alklyl amides in Capsicum and black pepper were dose dependant. The inhibitory concentrations 50% (IC50) of the alklylamides were in the range 13-200 microg/mL. The extracts of black pepper at 200 microg/mL and its compounds at 25 microg/mL inhibited LPO by 45-85%, COX enzymes by 31-80% and cancer cells proliferation by 3.5-86.8%. Overall, these results suggest that black pepper and its constituents like hot pepper, exhibit anti-inflammatory, antioxidant and anticancer activities.

Advances in the development of AMPK-activating compounds.

Science.gov (United States)

Sriwijitkamol, Apiradee; Musi, Nicolas

2008-10-01

AMP-activated protein kinase (AMPK) is an energy sensing enzyme that controls glucose and lipid metabolism. This review summarizes the present data on AMPK as a pharmacologic target for the treatment of metabolic disorders. The mechanisms governing AMPK activity and how this enzyme controls different metabolic pathways are reviewed briefly, and details about the effect that AMPK activators have on glucose metabolism are provided. Evidence obtained using the AMPK-activating compound 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR) suggests that AMPK promotes glucose transport into skeletal muscles and that this enzyme inhibits hepatic glucose production. AICAR also induces fatty acid oxidation in muscle and inhibits cholesterol synthesis in the liver. The metabolic effects of AICAR on glucose and lipid metabolism indicate that AMPK may be a good pharmacologic target for the treatment of type 2 diabetes and hypercholesterolemia. Novel AMPK-specific compounds are allowing researchers to examine whether this enzyme is a useful pharmacologic target for the treatment of human disease and whether chronic activation of AMPK will be safe.

Effusanin E suppresses nasopharyngeal carcinoma cell growth by inhibiting NF-κB and COX-2 signaling.

Directory of Open Access Journals (Sweden)

Mingzhu Zhuang

Full Text Available Rabdosia serra is well known for its antibacterial, anti-inflammatory and antitumor activities, but no information has been available for the active compounds derived from this plant in inhibiting human nasopharyngeal carcinoma (NPC cell growth. In this study, we isolated and purified a natural diterpenoid from Rabdosia serra and identified its chemical structure as effusanin E and elucidated its underlying mechanism of action in inhibiting NPC cell growth. Effusanin E significantly inhibited cell proliferation and induced apoptosis in NPC cells. Effusanin E also induced the cleavage of PARP, caspase-3 and -9 proteins and inhibited the nuclear translocation of p65 NF-κB proteins. Moreover, effusanin E abrogated the binding of NF-κB to the COX-2 promoter, thereby inhibiting the expression and promoter activity of COX-2. Pretreatment with a COX-2 or NF-κB-selective inhibitor (celecoxib or ammonium pyrrolidinedithiocarbamate had an additive effect on the effusanin E-mediated inhibition of proliferation, while pretreatment with an activator of NF-κB/COX-2 (lipopolysaccharides abrogated the effusanin E-mediated inhibition of proliferation. Effusanin E also significantly suppressed tumor growth in a xenograft mouse model without obvious toxicity, furthermore, the expression of p50 NF-κB and COX-2 were down-regulated in the tumors of nude mice. These data suggest that effusanin E suppresses p50/p65 proteins to down-regulate COX-2 expression, thereby inhibiting NPC cell growth. Our findings provide new insights into exploring effusanin E as a potential therapeutic compound for the treatment of human nasopharyngeal carcinoma.

Novel human topoisomerase I inhibitors, topopyrones A, B, C and D. I. Producing strain, fermentation, isolation, physico-chemical properties and biological activity.

Science.gov (United States)

Kanai, Y; Ishiyama, D; Senda, H; Iwatani, W; Takahashi, H; Konno, H; Tokumasu, S; Kanazawa, S

2000-09-01

In the course of a screening program for specific inhibitors of human topoisomerase I using a recombinant yeast, we have discovered four new active compounds. All four compounds were isolated from the culture broth of a fungus, Phoma sp. BAUA2861, and two of them were isolated from the culture broth of a fungus, Penicillium sp. BAUA4206. We designated these compounds as topopyrones A, B, C and D. Topopyrones A, B, C and D selectively inhibited recombinant yeast growth dependent on expression of human topoisomerase I with IC50 values of 1.22, 0.15, 4.88 and 19.63 ng/ml, respectively. The activity and selectivity of topopyrone B were comparable to those of camptothecin. The relaxation of supercoiled pBR322 DNA by human DNA topoisomerase I was inhibited by these compounds, however they did not inhibit human DNA topoisomerase II. Topopyrones A, B, C and D were cytotoxic to all tumor cell lines when tested in vitro. Topopyrone B has potent inhibitory activity against herpesvirus, especially varicella zoster virus (VZV). It inhibited VZV growth with EC50 value of 0.038 microg/ml, which is 24-fold stronger than that of acyclovir (0.9 microg/ml). Topopyrones A, B, and C were inhibitory to Gram-positive bacteria.

Metabolites from invasive pests inhibit mitochondrial complex II: A potential strategy for the treatment of human ovarian carcinoma?

Energy Technology Data Exchange (ETDEWEB)

Ferramosca, Alessandra, E-mail: alessandra.ferramosca@unisalento.it [Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Lecce (Italy); Conte, Annalea; Guerra, Flora; Felline, Serena [Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Lecce (Italy); Rimoli, Maria Grazia [Dipartimento di Farmacia, Università di Napoli Federico II, Napoli (Italy); Mollo, Ernesto [Istituto di Chimica Biomolecolare, Consiglio Nazionale delle Ricerche, Pozzuoli (Italy); Zara, Vincenzo [Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Lecce (Italy); Terlizzi, Antonio [Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Lecce (Italy); Stazione Zoologica Anton Dohrn, Napoli (Italy)

2016-05-13

The red pigment caulerpin, a secondary metabolite from the marine invasive green algae Caulerpa cylindracea can be accumulated and transferred along the trophic chain, with detrimental consequences on biodiversity and ecosystem functioning. Despite increasing research efforts to understand how caulerpin modifies fish physiology, little is known on the effects of algal metabolites on mammalian cells. Here we report for the first time the mitochondrial targeting activity of both caulerpin, and its closely related derivative caulerpinic acid, by using as experimental model rat liver mitochondria, a system in which bioenergetics mechanisms are not altered. Mitochondrial function was tested by polarographic and spectrophotometric methods. Both compounds were found to selectively inhibit respiratory complex II activity, while complexes I, III, and IV remained functional. These results led us to hypothesize that both algal metabolites could be used as antitumor agents in cell lines with defects in mitochondrial complex I. Ovarian cancer cisplatin-resistant cells are a good example of cell lines with a defective complex I function on which these molecules seem to have a toxic effect on proliferation. This provided novel insight toward the potential use of metabolites from invasive Caulerpa species for the treatment of human ovarian carcinoma cisplatin-resistant cells. -- Highlights: •Novel insight toward the potential use of the algal metabolites for the treatment of human diseases. •Caulerpin and caulerpinic acid inhibit respiratory complex II activity. •Both algal metabolites could be used as antitumor agents in ovarian cancer cisplatin-resistant cells.

Metabolites from invasive pests inhibit mitochondrial complex II: A potential strategy for the treatment of human ovarian carcinoma?

International Nuclear Information System (INIS)

Ferramosca, Alessandra; Conte, Annalea; Guerra, Flora; Felline, Serena; Rimoli, Maria Grazia; Mollo, Ernesto; Zara, Vincenzo; Terlizzi, Antonio

2016-01-01

The red pigment caulerpin, a secondary metabolite from the marine invasive green algae Caulerpa cylindracea can be accumulated and transferred along the trophic chain, with detrimental consequences on biodiversity and ecosystem functioning. Despite increasing research efforts to understand how caulerpin modifies fish physiology, little is known on the effects of algal metabolites on mammalian cells. Here we report for the first time the mitochondrial targeting activity of both caulerpin, and its closely related derivative caulerpinic acid, by using as experimental model rat liver mitochondria, a system in which bioenergetics mechanisms are not altered. Mitochondrial function was tested by polarographic and spectrophotometric methods. Both compounds were found to selectively inhibit respiratory complex II activity, while complexes I, III, and IV remained functional. These results led us to hypothesize that both algal metabolites could be used as antitumor agents in cell lines with defects in mitochondrial complex I. Ovarian cancer cisplatin-resistant cells are a good example of cell lines with a defective complex I function on which these molecules seem to have a toxic effect on proliferation. This provided novel insight toward the potential use of metabolites from invasive Caulerpa species for the treatment of human ovarian carcinoma cisplatin-resistant cells. -- Highlights: •Novel insight toward the potential use of the algal metabolites for the treatment of human diseases. •Caulerpin and caulerpinic acid inhibit respiratory complex II activity. •Both algal metabolites could be used as antitumor agents in ovarian cancer cisplatin-resistant cells.

Single-wall carbon nanohorns (SWNHs) inhibited proliferation of human glioma cells and promoted its apoptosis

Energy Technology Data Exchange (ETDEWEB)

Li, Yunjun [The Military General Hospital of Beijing PLA, Affiliated Bayi Brain Hospital (China); Zhang, Jinqian, E-mail: jingwanghou@yahoo.com.cn [Capital Medical University, Institute of Infectious Diseases, Beijing Ditan Hospital (China); Zhao, Ming [Peking University, Department of Chemical Biology, School of Pharmaceutical Sciences (China); Shi, Zujin [Peking University, Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering (China); Chen, Xin; He, Xihui; Han, Nanyin, E-mail: jingwanghou@sina.com [Peking University, Department of Chemical Biology, School of Pharmaceutical Sciences (China); Xu, Ruxiang, E-mail: everbright999@163.com [The Military General Hospital of Beijing PLA, Affiliated Bayi Brain Hospital (China)

2013-08-15

Although single-wall carbon nanohorns (SWNHs) have been demonstrated to accumulate to cytotoxic levels within organs of various animal models and cell types, they have been exploited for cancer therapies. The role of SWNHs in human glioma cell lines was unclear. To address this question, the research about direct role of SWNHs on the growth, proliferation, and apoptosis of human glioma cell lines (U87, U251, and U373) had been performed. Our results indicate that particle size of SWNHs in water is between 342 and 712 nm, the films of SEM show that SWNHs on PS surface are individual particles. SWNHs significantly delayed mitotic entry of human glioma cell lines cells, and inhibited its proliferation in a time- and dose-dependent manner. SWNHs induced a significant increase in G1 phase and inhibition of S phase followed the gradually increasing concentrations. SWNHs in human glioma cell lines cells significantly induced apoptosis followed by their gradually increasing concentrations. The TEM images showed that individual spherical SWNHs particles smaller than 100 nm in diameters were localized inside lysosomes of human glioma cell lines. SWNHs inhibited mitotic entry, growth, and proliferation of human glioma cell lines, and promoted its apoptosis. SWNHs may be a novel opportunity or method for the research on treatment of human glioma.

Single-wall carbon nanohorns (SWNHs) inhibited proliferation of human glioma cells and promoted its apoptosis

Science.gov (United States)

Li, Yunjun; Zhang, Jinqian; Zhao, Ming; Shi, Zujin; Chen, Xin; He, Xihui; Han, Nanyin; Xu, Ruxiang

2013-08-01

Although single-wall carbon nanohorns (SWNHs) have been demonstrated to accumulate to cytotoxic levels within organs of various animal models and cell types, they have been exploited for cancer therapies. The role of SWNHs in human glioma cell lines was unclear. To address this question, the research about direct role of SWNHs on the growth, proliferation, and apoptosis of human glioma cell lines (U87, U251, and U373) had been performed. Our results indicate that particle size of SWNHs in water is between 342 and 712 nm, the films of SEM show that SWNHs on PS surface are individual particles. SWNHs significantly delayed mitotic entry of human glioma cell lines cells, and inhibited its proliferation in a time- and dose-dependent manner. SWNHs induced a significant increase in G1 phase and inhibition of S phase followed the gradually increasing concentrations. SWNHs in human glioma cell lines cells significantly induced apoptosis followed by their gradually increasing concentrations. The TEM images showed that individual spherical SWNHs particles smaller than 100 nm in diameters were localized inside lysosomes of human glioma cell lines. SWNHs inhibited mitotic entry, growth, and proliferation of human glioma cell lines, and promoted its apoptosis. SWNHs may be a novel opportunity or method for the research on treatment of human glioma.

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.

TW-01, a piperazinedione-derived compound, inhibits Ras-mediated cell proliferation and angioplasty-induced vascular restenosis

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Lin, Chao-Feng [The Ph.D. Program for Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan (China); Department of Medicine, MacKay Medical College, New Taipei City, Taiwan (China); Division of Cardiology, Department of Internal Medicine, MacKay Memorial Hospital, Taipei, Taiwan (China); Division of Cardiology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan (China); Huang, Han-Li [The Ph.D. Program for Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan (China); Peng, Chieh-Yu [Chinese Medicine Research and Development Center, China Medical University Hospital, Taichung 404, Taiwan (China); School of Pharmacy, College of Pharmacy, China Medical University, Taichung 404, Taiwan (China); Lee, Yu-Ching [The Center of Translational Medicine, Taipei Medical University, Taipei, Taiwan (China); Ph.D. Program for Biotechnology in Medicine, Taipei Medical University, Taipei, Taiwan (China); Wang, Hui-Po [College of Pharmacy, Taipei Medical University, Taipei 11031, Taiwan (China); Teng, Che-Ming [College of Pharmacy, Taipei Medical University, Taipei 11031, Taiwan (China); Pharmacological Institute, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Pan, Shiow-Lin, E-mail: slpan@tmu.edu.tw [The Ph.D. Program for Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan (China); Department of Pharmacology, College of Medicine, Taipei Medical University, Taipei 10031, Taiwan (China)

2016-08-15

Purpose: Vascular smooth muscle cell (VSMC) proliferation plays a critical role in the pathogenesis of atherosclerosis and restenosis. This study investigated piperazinedione derived compound TW-01-mediated inhibitory effects on VSMC proliferation and intimal hyperplasia. Methods: Cell proliferation was determined using [{sup 3}H]-thymidine incorporation and MTT assay; cell cycle distribution was measured using flow cytometry; proteins and mRNA expression were determined using western blotting and RT-PCR analyses; DNA binding activity of nuclear factor-κB (NF-κB), as measured using enzyme-linked immunosorbent assays (ELISA); in vivo effects of TW-01 were determined using balloon angioplasty in the rat. Results: TW-01 significantly inhibited cell proliferation. At the concentrations used, no cytotoxic effects were observed. Three predominant signaling pathways were inhibited by TW-01: (a) extracellular signal-regulated kinase (ERK)1/2 mitogen-activated protein kinase (MAPK) activation and its downstream effectors of c-fos, c-jun, and c-myc; (b) DNA binding activity of nuclear factor-κB (NF-κB); and, (c) Akt/protein kinase B (PKB) and cell cycle progression. Furthermore, TW-01 also inhibited Ras activation, a shared upstream event of each of these signaling cascades. In vascular injury studies, oral administration of TW-01 significantly suppressed intimal hyperplasia induced by balloon angioplasty. Conclusion: The present study suggests that TW-01 might be a potential candidate for atherosclerosis treatment. - Highlights: • TW-01significantly inhibits vascular smooth muscle cell proliferation. • TW-01 inhibits ERK, Akt and Ras pathway and DNA binding activity of NF-κB. • TW-01 significantly suppresses intimal hyperplasia induced by balloon angioplasty. • TW-01 might be a potential candidate for atherosclerosis treatment.

TW-01, a piperazinedione-derived compound, inhibits Ras-mediated cell proliferation and angioplasty-induced vascular restenosis

International Nuclear Information System (INIS)

Lin, Chao-Feng; Huang, Han-Li; Peng, Chieh-Yu; Lee, Yu-Ching; Wang, Hui-Po; Teng, Che-Ming; Pan, Shiow-Lin

2016-01-01

Purpose: Vascular smooth muscle cell (VSMC) proliferation plays a critical role in the pathogenesis of atherosclerosis and restenosis. This study investigated piperazinedione derived compound TW-01-mediated inhibitory effects on VSMC proliferation and intimal hyperplasia. Methods: Cell proliferation was determined using [ 3 H]-thymidine incorporation and MTT assay; cell cycle distribution was measured using flow cytometry; proteins and mRNA expression were determined using western blotting and RT-PCR analyses; DNA binding activity of nuclear factor-κB (NF-κB), as measured using enzyme-linked immunosorbent assays (ELISA); in vivo effects of TW-01 were determined using balloon angioplasty in the rat. Results: TW-01 significantly inhibited cell proliferation. At the concentrations used, no cytotoxic effects were observed. Three predominant signaling pathways were inhibited by TW-01: (a) extracellular signal-regulated kinase (ERK)1/2 mitogen-activated protein kinase (MAPK) activation and its downstream effectors of c-fos, c-jun, and c-myc; (b) DNA binding activity of nuclear factor-κB (NF-κB); and, (c) Akt/protein kinase B (PKB) and cell cycle progression. Furthermore, TW-01 also inhibited Ras activation, a shared upstream event of each of these signaling cascades. In vascular injury studies, oral administration of TW-01 significantly suppressed intimal hyperplasia induced by balloon angioplasty. Conclusion: The present study suggests that TW-01 might be a potential candidate for atherosclerosis treatment. - Highlights: • TW-01significantly inhibits vascular smooth muscle cell proliferation. • TW-01 inhibits ERK, Akt and Ras pathway and DNA binding activity of NF-κB. • TW-01 significantly suppresses intimal hyperplasia induced by balloon angioplasty. • TW-01 might be a potential candidate for atherosclerosis treatment.

Inhibition of DNA repair in ultraviolet-irradiated human cells by hydroxyurea

International Nuclear Information System (INIS)

Francis, A.A.; Carrier, W.L.; Smith, D.P.; Regan, J.D.; Blevins, R.D.

1979-01-01

The effect on DNA repair in ultraviolet-irradiated human skin fibroblasts by hydroxyurea has been examined in this study using three independent methods for measuring DNA repair: the 5-bromodeoxyuridine photolysis assay which measures DNA repair replication, chromatographic measurement of thymine-containing dimers, and measurement of specific ultraviolet-endonuclease-sensitive sites in irradiated DNA. Little effect on hydroxyurea was observed at the concentration of 2mM, which is often used to inhibit semiconservative DNA synthesis; however, 10 mM hydroxyurea resulted in marked inhibition (65-70%) of excision repair. This inhibition was accompanied by a possible doubling in the size of the repaired region. The accumulation of large numbers of single-strand breaks following ultraviolet irradiation and hydroxyurea incubation seen by other investigators was not observed with the normal skin fibroblasts used in this study. A comparison of hydroxyurea effects on the different DNA repair assays indicates inhibition of one step in DNA repair also results in varying degrees of inhibition of other steps as well. (Auth.)

Inhibition of DNA repair in ultraviolet-irradiated human cells by hydroxyurea

Energy Technology Data Exchange (ETDEWEB)

Francis, A.A. (Oak Ridge National Lab., TN); Blevins, R.D.; Carrier, W.L.; Smith, D.P.; Regan, J.D.

1979-01-01

The effect on DNA repair in ultraviolet-irradiated human skin fibroblasts by hydroxyurea has been examined in this study using three independent methods for measuring DNA repair: the 5-bromodeoxyuridine photolysis assay which measures DNA repair replication, chromatographic measurement of thymine-containing dimers, and measurement of specific ultraviolet-endonuclease-sensitive sites in irradiated DNA. Little effect of hydroxyurea was observed at the concentration of 2 mM, which is often used to inhibit semiconservative DNA synthesis; however, 10 mM hydroxyurea resulted in marked inhibition (65 to 70%) of excision repair. This inhibition was accompanied by a possible doubling in the size of the repaired region. The accumulation of large numbers of single-strand breaks following ultraviolet irradiation and hydroxyurea incubation seen by other investigators was not observed with the normal skin fibroblasts used in this study. A comparison of hydroxyurea effects on the different DNA repair assays indicates inhibition of one step in DNA repair also results in varying degrees of inhibition of other steps as well.

Organotin compounds cause structure-dependent induction of progesterone in human choriocarcinoma Jar cells.

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Hiromori, Youhei; Yui, Hiroki; Nishikawa, Jun-ichi; Nagase, Hisamitsu; Nakanishi, Tsuyoshi

2016-01-01

Organotin compounds, such as tributyltin (TBT) and triphenyltin (TPT), are typical environmental contaminants and suspected endocrine-disrupting chemicals because they cause masculinization in female mollusks. In addition, previous studies have suggested that the endocrine disruption by organotin compounds leads to activation of peroxisome proliferator-activated receptor (PPAR)γ and retinoid X receptor (RXR). However, whether organotin compounds cause crucial toxicities in human development and reproduction is unclear. We here investigated the structure-dependent effect of 12 tin compounds on mRNA transcription of 3β-hydroxysteroid dehydrogenase type I (3β-HSD I) and progesterone production in human choriocarcinoma Jar cells. TBT, TPT, dibutyltin, monophenyltin, tripropyltin, and tricyclohexyltin enhanced progesterone production in a dose-dependent fashion. Although tetraalkyltin compounds such as tetrabutyltin increased progesterone production, the concentrations necessary for activation were 30-100 times greater than those for trialkyltins. All tested active organotins increased 3β-HSD I mRNA transcription. We further investigated the correlation between the agonistic activity of organotin compounds on PPARγ and their ability to promote progesterone production. Except for DBTCl2, the active organotins significantly induced the transactivation function of PPARγ. In addition, PPARγ knockdown significantly suppressed the induction of mRNA transcription of 3β-HSD I by all active organotins except DBTCl2. These results suggest that some organotin compounds promote progesterone biosynthesis in vitro by inducing 3β-HSD I mRNA transcription via the PPARγ signaling pathway. The placenta represents a potential target organ for these compounds, whose endocrine-disrupting effects might cause local changes in progesterone concentration in pregnant women. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inhibition of fatty acid metabolism reduces human myeloma cells proliferation.

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José Manuel Tirado-Vélez

Full Text Available Multiple myeloma is a haematological malignancy characterized by the clonal proliferation of plasma cells. It has been proposed that targeting cancer cell metabolism would provide a new selective anticancer therapeutic strategy. In this work, we tested the hypothesis that inhibition of β-oxidation and de novo fatty acid synthesis would reduce cell proliferation in human myeloma cells. We evaluated the effect of etomoxir and orlistat on fatty acid metabolism, glucose metabolism, cell cycle distribution, proliferation, cell death and expression of G1/S phase regulatory proteins in myeloma cells. Etomoxir and orlistat inhibited β-oxidation and de novo fatty acid synthesis respectively in myeloma cells, without altering significantly glucose metabolism. These effects were associated with reduced cell viability and cell cycle arrest in G0/G1. Specifically, etomoxir and orlistat reduced by 40-70% myeloma cells proliferation. The combination of etomoxir and orlistat resulted in an additive inhibitory effect on cell proliferation. Orlistat induced apoptosis and sensitized RPMI-8226 cells to apoptosis induction by bortezomib, whereas apoptosis was not altered by etomoxir. Finally, the inhibitory effect of both drugs on cell proliferation was associated with reduced p21 protein levels and phosphorylation levels of retinoblastoma protein. In conclusion, inhibition of fatty acid metabolism represents a potential therapeutic approach to treat human multiple myeloma.

Compounds Released from Biomass Deconstruction: Understanding Their Effect on Cellulose Enzyme Hydrolysis and Their Biological Activity

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Djioleu, Angele Mezindjou

aureus growth and copper-induced peroxidation of human low-density lipoprotein, confirming antimicrobial and antioxidant activities of the extract. On the other hand, bark extract inhibited cellulase cocktail activity by reducing cellulose hydrolysis by 82.32% after 48 h of incubation. Overall, phenolic compounds generated from biomass fractionation are important players in cellulolytic enzyme inhibition; removal of biomass extractives prior to pretreatment could reduce inhibitory compounds in prehydrolyzate while generating phytochemicals with societal benefits.

Inhibition of Mast Cell-Mediated Allergic Responses by Arctii Fructus Extracts and Its Main Compound Arctigenin.

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Kee, Ji-Ye; Hong, Seung-Heon

2017-11-01

The Arctium lappa seeds (Arctii Fructus) and its major active compound, arctigenin (ARC), are known to have anticancer, antiobesity, antiosteoporosis, and anti-inflammatory activities. However, the effect of Arctii Fructus and ARC on mast cell-mediated allergic inflammation and its associated mechanism have not been elucidated. Therefore, we attempted to investigate the antiallergic activity of Arctii Fructus and ARC on mast cells and experimental mouse models. Arctii Fructus water extract (AFW) or ethanol extract (AFE) and ARC reduced the production of histamine and pro-inflammatory cytokines such as interleukin (IL)-1β, IL-6, IL-8, and TNF-α in mast cells. AFW, AFE, and ARC inhibited phosphorylation of MAPKs and NF-κB in activated mast cells. Moreover, IgE-mediated passive cutaneous anaphylaxis and compound 48/80-induced anaphylactic shock were suppressed by AFW, AFE, and ARC administration. These results suggest that Arctii Fructus and ARC are potential therapeutic agents against allergic inflammatory diseases.

Compound A398, a novel podophyllotoxin analogue: cytotoxicity and induction of apoptosis in human leukemia cells.

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Alethéia L Silveira

Full Text Available Despite advances in oncology research, cancer is one of the leading causes of death worldwide. Thus, there is a demand for the development of more selective and effective antitumor agents. This study showed that A398, a novel podophyllotoxin analogue, was cytotoxic to the HT-29, MCF-7, MOLT-4 and HL-60 tumor cell lines, being less active in human peripheral blood mononuclear cells and normal cell lines FGH and IEC-6. Tests using the HepG2 lineage indicated that its metabolites do not contribute to its cytotoxicity. In the HL-60 cells, A398 induced apoptosis in a time and concentration-dependent manner, promoting mitochondrial depolarization, inhibition of Bcl-2, phosphatidylserine exposure, activation of caspases -8, -9 and -3, and DNA fragmentation. The production of reactive oxygen species does not seem to be a crucial event for the apoptotic process. Pretreatment with specific inhibitors of kinases ERK1/2, JNK and p38 resulted in an increased percentage of death induced by A398. These results indicate that the compound induced apoptosis through activation of intrinsic and extrinsic death pathways with the mechanism involving the inhibition of the MAPKs and Bcl-2. Taken together, our findings suggest that A398 has an anticancer potential, proving itself to be a candidate for preclinical studies.

Structure-activity relationships of amide-phosphonate derivatives as inhibitors of the human soluble epoxide hydrolase.

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Kim, In-Hae; Park, Yong-Kyu; Nishiwaki, Hisashi; Hammock, Bruce D; Nishi, Kosuke

2015-11-15

Structure-activity relationships of amide-phosphonate derivatives as inhibitors of the human soluble epoxide hydrolase (sEH) were investigated. First, a series of alkyl or aryl groups were substituted on the carbon alpha to the phosphonate function in amide compounds to see whether substituted phosphonates can act as a secondary pharmacophore. A tert-butyl group (16) on the alpha carbon was found to yield most potent inhibition on the target enzyme. A 4-50-fold drop in inhibition was induced by other substituents such as aryls, substituted aryls, cycloalkyls, and alkyls. Then, the modification of the O-substituents on the phosphonate function revealed that diethyl groups (16 and 23) were preferable for inhibition to other longer alkyls or substituted alkyls. In amide compounds with the optimized diethylphosphonate moiety and an alkyl substitution such as adamantane (16), tetrahydronaphthalene (31), or adamantanemethane (36), highly potent inhibitions were gained. In addition, the resulting potent amide-phosphonate compounds had reasonable water solubility, suggesting that substituted phosphonates in amide inhibitors are effective for both inhibition potency on the human sEH and water solubility as a secondary pharmacophore. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inhibition of human immunodeficiency virus type 1 (HIV-1) nuclear import via Vpr-Importin α interactions as a novel HIV-1 therapy

International Nuclear Information System (INIS)

Suzuki, Tatsunori; Yamamoto, Norio; Nonaka, Mizuho; Hashimoto, Yoshie; Matsuda, Go; Takeshima, Shin-nosuke; Matsuyama, Megumi; Igarashi, Tatsuhiko; Miura, Tomoyuki; Tanaka, Rie; Kato, Shingo; Aida, Yoko

2009-01-01

The development of multidrug-resistant viruses compromises the efficacy of anti-human immunodeficiency virus (HIV) therapy and limits treatment options. Therefore, new targets that can be used to develop novel antiviral agents need to be identified. One such target is the interaction between Vpr, one of the accessory gene products of HIV-1 and Importin α, which is crucial, not only for the nuclear import of Vpr, but also for HIV-1 replication in macrophages. We have identified a potential parent compound, hematoxylin, which suppresses Vpr-Importin α interaction, thereby inhibiting HIV-1 replication in a Vpr-dependent manner. Analysis by real-time PCR demonstrated that hematoxylin specifically inhibited nuclear import step of pre-integration complex. Thus, hematoxylin is a new anti-HIV-1 inhibitor that targets the nuclear import of HIV-1 via the Vpr-Importin α interaction, suggesting that a specific inhibitor of the interaction between viral protein and the cellular factor may provide a new strategy for HIV-1 therapy.

Anti-tumor effects of novel 5-O-acyl plumbagins based on the inhibition of mammalian DNA replicative polymerase activity.

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Moe Kawamura

Full Text Available We previously found that vitamin K3 (menadione, 2-methyl-1,4-naphthoquinone inhibits the activity of human mitochondrial DNA polymerase γ (pol γ. In this study, we focused on plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone, and chemically synthesized novel plumbagins conjugated with C2:0 to C22:6 fatty acids (5-O-acyl plumbagins. These chemically modified plumbagins enhanced mammalian pol inhibition and their cytotoxic activity. Plumbagin conjugated with chains consisting of more than C18-unsaturated fatty acids strongly inhibited the activities of calf pol α and human pol γ. Plumbagin conjugated with oleic acid (C18:1-acyl plumbagin showed the strongest suppression of human colon carcinoma (HCT116 cell proliferation among the ten synthesized 5-O-acyl plumbagins. The inhibitory activity on pol α, a DNA replicative pol, by these compounds showed high correlation with their cancer cell proliferation suppressive activity. C18:1-Acyl plumbagin selectively inhibited the activities of mammalian pol species, but did not influence the activities of other pols and DNA metabolic enzymes tested. This compound inhibited the proliferation of various human cancer cell lines, and was the cytotoxic inhibitor showing strongest inhibition towards HT-29 colon cancer cells (LD50 = 2.9 µM among the nine cell lines tested. In an in vivo anti-tumor assay conducted on nude mice bearing solid tumors of HT-29 cells, C18:1-acyl plumbagin was shown to be a promising tumor suppressor. These data indicate that novel 5-O-acyl plumbagins act as anti-cancer agents based on mammalian DNA replicative pol α inhibition. Moreover, the results suggest that acylation of plumbagin is an effective chemical modification to improve the anti-cancer activity of vitamin K3 derivatives, such as plumbagin.

Inhibition of JAK3 and PKC via Immunosuppressive Drugs Tofacitinib and Sotrastaurin Inhibits Proliferation of Human B Lymphocytes In Vitro.

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Martina, M N; Ramirez Bajo, M J; Bañon-Maneus, E; Moya Rull, D; Hierro-Garcia, N; Revuelta, I; Campistol, J M; Rovira, J; Diekmann, F

2016-11-01

Antibody-mediated response in solid organ transplantation is critical for graft dysfunction and loss. The use of immunosuppressive agents partially inhibits the B-lymphocyte response leading to a risk of acute and chronic antibody-mediated rejection. This study evaluated the impact of JAK3 and PKC inhibitors tofacitinib (Tofa) and sotrastaurin (STN), respectively, on B-cell proliferation, apoptosis, and activation in vitro. Human B cells isolated from peripheral blood of healthy volunteers were cocultured with CD40 ligand-transfected fibroblasts as feeder cells in the presence of interleukin (IL) 2, IL-10, and IL-21. The cocultures were treated with immunosuppressants Tofa, STN, and rapamycin (as a control), to analyze the proliferation and apoptosis of B cells by means of Cyquant and flow cytometry, respectively. CD27 and IgG staining were applied to evaluate whether treatments modified the activation of B cells. Tofa and STN were able to inhibit B-cell proliferation to the same extent as rapamycin, without inducing cell apoptosis. After 6 days in coculture with feeder cells, all B cells showed CD27 memory B-cell phenotype. None of the immunosuppressive treatments modified the proportion between class-switched and non-class-switched memory B cells observed in nontreated cultures. The high predominance of CD27 + CD24 + phenotype was not modified by any immunosuppressive treatment. Our results show that Tofa and STN can suppress B-cell antibody responses to an extent similar to rapamycin, in vitro; therefore these compounds may be a useful therapy against antibody-mediated rejection in transplantation. Copyright © 2016. Published by Elsevier Inc.

Human studies of prepulse inhibition of startle: normal subjects, patient groups, and pharmacological studies.

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Braff, D L; Geyer, M A; Swerdlow, N R

2001-07-01

Since the mid-1970s, cross-species translational studies of prepulse inhibition (PPI) have increased at an astounding pace as the value of this neurobiologically informative measure has been optimized. PPI occurs when a relatively weak sensory event (the prepulse) is presented 30-500 ms before a strong startle-inducing stimulus, and reduces the magnitude of the startle response. In humans, PPI occurs in a robust, predictable manner when the prepulse and startling stimuli occur in either the same or different modalities (acoustic, visual, or cutaneous). This review covers three areas of interest in human PPI studies. First, we review the normal influences on PPI related to the underlying construct of sensori- (prepulse) motor (startle reflex) gating. Second, we review PPI studies in psychopathological disorders that form a family of gating disorders. Third, we review the relatively limited but interesting and rapidly expanding literature on pharmacological influences on PPI in humans. All studies identified by a computerized literature search that addressed the three topics of this review were compiled and evaluated. The principal studies were summarized in appropriate tables. The major influences on PPI as a measure of sensorimotor gating can be grouped into 11 domains. Most of these domains are similar across species, supporting the value of PPI studies in translational comparisons across species. The most prominent literature describing deficits in PPI in psychiatrically defined groups features schizophrenia-spectrum patients and their clinically unaffected relatives. These findings support the use of PPI as an endophenotype in genetic studies. Additional groups of psychopathologically disordered patients with neuropathology involving cortico-striato-pallido-pontine circuits exhibit poor gating of motor, sensory, or cognitive information and corresponding PPI deficits. These groups include patients with obsessive compulsive disorder, Tourette's syndrome

Tumor necrosis factor-alpha inhibits differentiation of myogenic cells in human urethral rhabdosphincter.

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Shinohara, Mayuka; Sumino, Yasuhiro; Sato, Fuminori; Kiyono, Tohru; Hashimoto, Naohiro; Mimata, Hiromitsu

2017-06-01

To examine the inhibitory effects of tumor necrosis factor-α on myogenic differentiation of human urethral rhabdosphincter cells. A rhabdosphincter sample was obtained from a patient who underwent total cystectomy. To expand the lifespan of the primary cultured cells, rhabdosphincter myogenic cells were immortalized with mutated cyclin-dependent kinase 4, cyclin D1 and telomerase. The differential potential of the cells was investigated. The transfected human rhabdosphincter cells were induced for myogenic differentiation with recombinant human tumor necrosis factor-α and/or the tumor necrosis factor-α antagonist etanercept at different concentrations, and activation of signaling pathways was monitored. Human rhabdosphincter cells were selectively cultured for at least 40 passages. Molecular analysis confirmed the expression of myosin heavy chain, which is a specific marker of differentiated muscle cells, significantly increased after differentiation induction. Although tumor necrosis factor-α treatment reduced the myosin heavy chain expression in a concentration-dependent manner, etanercept inhibited this suppression. Tumor necrosis factor-α suppressed phosphorylation of protein kinase B and p38, whereas etanercept pretreatment promoted phosphorylation and myosin heavy chain expression in a concentration-dependent manner. Tumor necrosis factor-α inhibits differentiation of urethral rhabdosphincter cells in part through the p38 mitogen-activated protein kinase and phosphoinositide 3-kinase pathways. Inhibition of tumor necrosis factor-α might be a useful strategy to treat stress urinary incontinence. © 2017 The Japanese Urological Association.

Improvement of a synthetic lure for Anopheles gambiae using compounds produced by human skin microbiota.

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Verhulst, Niels O; Mbadi, Phoebe A; Kiss, Gabriella Bukovinszkiné; Mukabana, Wolfgang R; van Loon, Joop J A; Takken, Willem; Smallegange, Renate C

2011-02-08

Anopheles gambiae sensu stricto is considered to be highly anthropophilic and volatiles of human origin provide essential cues during its host-seeking behaviour. A synthetic blend of three human-derived volatiles, ammonia, lactic acid and tetradecanoic acid, attracts A. gambiae. In addition, volatiles produced by human skin bacteria are attractive to this mosquito species. The purpose of the current study was to test the effect of ten compounds present in the headspace of human bacteria on the host-seeking process of A. gambiae. The effect of each of the ten compounds on the attractiveness of a basic blend of ammonia, lactic and tetradecanoic acid to A. gambiae was examined. The host-seeking response of A. gambiae was evaluated in a laboratory set-up using a dual-port olfactometer and in a semi-field facility in Kenya using MM-X traps. Odorants were released from LDPE sachets and placed inside the olfactometer as well as in the MM-X traps. Carbon dioxide was added in the semi-field experiments, provided from pressurized cylinders or fermenting yeast. The olfactometer and semi-field set-up allowed for high-throughput testing of the compounds in blends and in multiple concentrations. Compounds with an attractive or inhibitory effect were identified in both bioassays. 3-Methyl-1-butanol was the best attractant in both set-ups and increased the attractiveness of the basic blend up to three times. 2-Phenylethanol reduced the attractiveness of the basic blend in both bioassays by more than 50%. Identification of volatiles released by human skin bacteria led to the discovery of compounds that have an impact on the host-seeking behaviour of A. gambiae. 3-Methyl-1-butanol may be used to increase mosquito trap catches, whereas 2-phenylethanol has potential as a spatial repellent. These two compounds could be applied in push-pull strategies to reduce mosquito numbers in malaria endemic areas.

Quorum Sensing Inhibition by Asparagopsis taxiformis, a Marine Macro Alga: Separation of the Compound that Interrupts Bacterial Communication

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Anton Hartmann

2013-01-01

Full Text Available The majority of the marine algal species, though completing their life cycle in seawater, are rarely susceptible to fouling, making them an important source of quorum sensing (QS inhibitory substances. The separation and characterization of QS inhibitors are crucial for any potential application. Thirty marine macroalgae were tested for QS inhibition activity by using Chromobacterium violaceum CV026 as the reporter strain, and among them, Asparagopsis taxiformis showed antibacterial, as well as antiquorum, sensing activities. Cinnamaldehyde (75 mM and methanol were used as positive and negative controls, respectively. The antiquorum sensing activity of A. taxiformis was further confirmed using the sensor strain, Serratia liquefaciens MG44, having green fluorescent protein (gfp. Methanolic extract of the alga was fractionated by solid phase extraction (SPE, and each fraction was tested for QS inhibition. Two types of activities were observed—zone of clearance (antibacterial activity and zone of inhibition with or without finger-like projections (QS inhibition. Out of five SPE cartridges, Bond Elut PH showed clear separation of these two fractions. The Ion Cyclotron Resonance Fourier Transformation Mass Spectrometer (ICR-FT/MS analysis of the fractions further supported the bioassay results. The presence of strong QS inhibitory compound in A. taxiformis indicates its potential use in antifouling preparations.

Synthesis and Antiplatelet Activity of Antithrombotic Thiourea Compounds: Biological and Structure-Activity Relationship Studies

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André Luiz Lourenço

2015-04-01

Full Text Available The incidence of hematological disorders has increased steadily in Western countries despite the advances in drug development. The high expression of the multi-resistance protein 4 in patients with transitory aspirin resistance, points to the importance of finding new molecules, including those that are not affected by these proteins. In this work, we describe the synthesis and biological evaluation of a series of N,N'-disubstituted thioureas derivatives using in vitro and in silico approaches. New designed compounds inhibit the arachidonic acid pathway in human platelets. The most active thioureas (compounds 3d, 3i, 3m and 3p displayed IC50 values ranging from 29 to 84 µM with direct influence over in vitro PGE2 and TXA2 formation. In silico evaluation of these compounds suggests that direct blockage of the tyrosyl-radical at the COX-1 active site is achieved by strong hydrophobic contacts as well as electrostatic interactions. A low toxicity profile of this series was observed through hemolytic, genotoxic and mutagenic assays. The most active thioureas were able to reduce both PGE2 and TXB2 production in human platelets, suggesting a direct inhibition of COX-1. These results reinforce their promising profile as lead antiplatelet agents for further in vivo experimental investigations.

Identification of anti-virulence compounds that disrupt quorum-sensing regulated acute and persistent pathogenicity.

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Melissa Starkey

2014-08-01

Full Text Available Etiological agents of acute, persistent, or relapsing clinical infections are often refractory to antibiotics due to multidrug resistance and/or antibiotic tolerance. Pseudomonas aeruginosa is an opportunistic Gram-negative bacterial pathogen that causes recalcitrant and severe acute chronic and persistent human infections. Here, we target the MvfR-regulated P. aeruginosa quorum sensing (QS virulence pathway to isolate robust molecules that specifically inhibit infection without affecting bacterial growth or viability to mitigate selective resistance. Using a whole-cell high-throughput screen (HTS and structure-activity relationship (SAR analysis, we identify compounds that block the synthesis of both pro-persistence and pro-acute MvfR-dependent signaling molecules. These compounds, which share a benzamide-benzimidazole backbone and are unrelated to previous MvfR-regulon inhibitors, bind the global virulence QS transcriptional regulator, MvfR (PqsR; inhibit the MvfR regulon in multi-drug resistant isolates; are active against P. aeruginosa acute and persistent murine infections; and do not perturb bacterial growth. In addition, they are the first compounds identified to reduce the formation of antibiotic-tolerant persister cells. As such, these molecules provide for the development of next-generation clinical therapeutics to more effectively treat refractory and deleterious bacterial-human infections.

Novel PI3K/Akt Inhibitors Screened by the Cytoprotective Function of Human Immunodeficiency Virus Type 1 Tat

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Kim, Dong-Hyun; Kim, Baek

2011-01-01

The PI3K/Akt pathway regulates various stress-related cellular responses such as cell survival, cell proliferation, metabolism and protein synthesis. Many cancer cell types display the activation of this pathway, and compounds inhibiting this cell survival pathway have been extensively evaluated as anti-cancer agents. In addition to cancers, several human viruses, such as HTLV, HPV, HCV and HIV-1, also modulate this pathway, presumably in order to extend the life span of the infected target cells for productive viral replication. The expression of HIV-1 Tat protein exhibited the cytoprotective effect in macrophages and a human microglial cell line by inhibiting the negative regulator of this pathway, PTEN. This cytoprotective effect of HIV-1 appears to contribute to the long-term survival and persistent HIV-1 production in human macrophage reservoirs. In this study we exploited the PI3K/Akt dependent cytoprotective effect of Tat-expressing CHME5 cells. We screened a collection of compounds known to modulate inflammation, and identified three novel compounds: Lancemaside A, Compound K and Arctigenin that abolished the cytoprotective phenotype of Tat-expressing CHME5 cells. All three compounds antagonized the kinase activity of Akt. Further detailed signaling studies revealed that each of these three compounds targeted different steps of the PI3K/Akt pathway. Arctigenin regulates the upstream PI3K enzyme from converting PIP2 to PIP3. Lancemaside A1 inhibited the movement of Akt to the plasma membrane, a critical step for Akt activation. Compound K inhibited Akt phosphorylation. This study supports that Tat-expressing CHME5 cells are an effective model system for screening novel PI3K/Akt inhibitors. PMID:21765914

Novel PI3K/Akt inhibitors screened by the cytoprotective function of human immunodeficiency virus type 1 Tat.

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Yuri Kim

Full Text Available The PI3K/Akt pathway regulates various stress-related cellular responses such as cell survival, cell proliferation, metabolism and protein synthesis. Many cancer cell types display the activation of this pathway, and compounds inhibiting this cell survival pathway have been extensively evaluated as anti-cancer agents. In addition to cancers, several human viruses, such as HTLV, HPV, HCV and HIV-1, also modulate this pathway, presumably in order to extend the life span of the infected target cells for productive viral replication. The expression of HIV-1 Tat protein exhibited the cytoprotective effect in macrophages and a human microglial cell line by inhibiting the negative regulator of this pathway, PTEN. This cytoprotective effect of HIV-1 appears to contribute to the long-term survival and persistent HIV-1 production in human macrophage reservoirs. In this study we exploited the PI3K/Akt dependent cytoprotective effect of Tat-expressing CHME5 cells. We screened a collection of compounds known to modulate inflammation, and identified three novel compounds: Lancemaside A, Compound K and Arctigenin that abolished the cytoprotective phenotype of Tat-expressing CHME5 cells. All three compounds antagonized the kinase activity of Akt. Further detailed signaling studies revealed that each of these three compounds targeted different steps of the PI3K/Akt pathway. Arctigenin regulates the upstream PI3K enzyme from converting PIP2 to PIP3. Lancemaside A1 inhibited the movement of Akt to the plasma membrane, a critical step for Akt activation. Compound K inhibited Akt phosphorylation. This study supports that Tat-expressing CHME5 cells are an effective model system for screening novel PI3K/Akt inhibitors.

A Novel indole compound that inhibits Pseudomonas aeruginosa growth by targeting MreB is a substrate for MexAB-OprM.

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Robertson, Gregory T; Doyle, Timothy B; Du, Qun; Duncan, Leonard; Mdluli, Khisimuzi E; Lynch, A Simon

2007-10-01

Drug efflux systems contribute to the intrinsic resistance of Pseudomonas aeruginosa to many antibiotics and biocides and hamper research focused on the discovery and development of new antimicrobial agents targeted against this important opportunistic pathogen. Using a P. aeruginosa PAO1 derivative bearing deletions of opmH, encoding an outer membrane channel for efflux substrates, and four efflux pumps belonging to the resistance nodulation/cell division class including mexAB-oprM, we identified a small-molecule indole-class compound (CBR-4830) that is inhibitory to growth of this efflux-compromised strain. Genetic studies established MexAB-OprM as the principal pump for CBR-4830 and revealed MreB, a prokaryotic actin homolog, as the proximal cellular target of CBR-4830. Additional studies establish MreB as an essential protein in P. aeruginosa, and efflux-compromised strains treated with CBR-4830 transition to coccoid shape, consistent with MreB inhibition or depletion. Resistance genetics further suggest that CBR-4830 interacts with the putative ATP-binding pocket in MreB and demonstrate significant cross-resistance with A22, a structurally unrelated compound that has been shown to promote rapid dispersion of MreB filaments in vivo. Interestingly, however, ATP-dependent polymerization of purified recombinant P. aeruginosa MreB is blocked in vitro in a dose-dependent manner by CBR-4830 but not by A22. Neither compound exhibits significant inhibitory activity against mutant forms of MreB protein that bear mutations identified in CBR-4830-resistant strains. Finally, employing the strains and reagents prepared and characterized during the course of these studies, we have begun to investigate the ability of analogues of CBR-4830 to inhibit the growth of both efflux-proficient and efflux-compromised P. aeruginosa through specific inhibition of MreB function.

Inhibition of nuclear factor-kappa B activation decreases survival of Mycobacterium tuberculosis in human macrophages.

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Xiyuan Bai

Full Text Available Nuclear factor-kappa B (NFκB is a ubiquitous transcription factor that mediates pro-inflammatory responses required for host control of many microbial pathogens; on the other hand, NFκB has been implicated in the pathogenesis of other inflammatory and infectious diseases. Mice with genetic disruption of the p50 subunit of NFκB are more likely to succumb to Mycobacterium tuberculosis (MTB. However, the role of NFκB in host defense in humans is not fully understood. We sought to examine the role of NFκB activation in the immune response of human macrophages to MTB. Targeted pharmacologic inhibition of NFκB activation using BAY 11-7082 (BAY, an inhibitor of IκBα kinase or an adenovirus construct with a dominant-negative IκBα significantly decreased the number of viable intracellular mycobacteria recovered from THP-1 macrophages four and eight days after infection. The results with BAY were confirmed in primary human monocyte-derived macrophages and alveolar macrophages. NFκB inhibition was associated with increased macrophage apoptosis and autophagy, which are well-established killing mechanisms of intracellular MTB. Inhibition of the executioner protease caspase-3 or of the autophagic pathway significantly abrogated the effects of BAY. We conclude that NFκB inhibition decreases viability of intracellular MTB in human macrophages via induction of apoptosis and autophagy.

Antihelminth compound niclosamide downregulates Wnt signaling and elicits antitumor responses in tumors with activating APC mutations.

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Osada, Takuya; Chen, Minyong; Yang, Xiao Yi; Spasojevic, Ivan; Vandeusen, Jeffrey B; Hsu, David; Clary, Bryan M; Clay, Timothy M; Chen, Wei; Morse, Michael A; Lyerly, H Kim

2011-06-15

Wnt/β-catenin pathway activation caused by adenomatous polyposis coli (APC) mutations occurs in approximately 80% of sporadic colorectal cancers (CRC). The antihelminth compound niclosamide downregulates components of the Wnt pathway, specifically Dishevelled-2 (Dvl2) expression, resulting in diminished downstream β-catenin signaling. In this study, we determined whether niclosamide could inhibit the Wnt/β-catenin pathway in human CRCs and whether its inhibition might elicit antitumor effects in the presence of APC mutations. We found that niclosamide inhibited Wnt/β-catenin pathway activation, downregulated Dvl2, decreased downstream β-catenin signaling, and exerted antiproliferative effects in human colon cancer cell lines and CRC cells isolated by surgical resection of metastatic disease, regardless of mutations in APC. In contrast, inhibition of NF-κB or mTOR did not exert similar antiproliferative effects in these CRC model systems. In mice implanted with human CRC xenografts, orally administered niclosamide was well tolerated, achieved plasma and tumor levels associated with biologic activity, and led to tumor control. Our findings support clinical explorations to reposition niclosamide for the treatment of CRC.

Comparative sensitivity of human and rat neural cultures to chemical-induced inhibition of neurite outgrowth

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Harrill, Joshua A.; Freudenrich, Theresa M.; Robinette, Brian L.; Mundy, William R., E-mail: mundy.william@epa.gov

2011-11-15

There is a need for rapid, efficient and cost-effective alternatives to traditional in vivo developmental neurotoxicity testing. In vitro cell culture models can recapitulate many of the key cellular processes of nervous system development, including neurite outgrowth, and may be used as screening tools to identify potential developmental neurotoxicants. The present study compared primary rat cortical cultures and human embryonic stem cell-derived neural cultures in terms of: 1) reproducibility of high content image analysis based neurite outgrowth measurements, 2) dynamic range of neurite outgrowth measurements and 3) sensitivity to chemicals which have been shown to inhibit neurite outgrowth. There was a large increase in neurite outgrowth between 2 and 24 h in both rat and human cultures. Image analysis data collected across multiple cultures demonstrated that neurite outgrowth measurements in rat cortical cultures were more reproducible and had higher dynamic range as compared to human neural cultures. Human neural cultures were more sensitive than rat cortical cultures to chemicals previously shown to inhibit neurite outgrowth. Parallel analysis of morphological (neurite count, neurite length) and cytotoxicity (neurons per field) measurements were used to detect selective effects on neurite outgrowth. All chemicals which inhibited neurite outgrowth in rat cortical cultures did so at concentrations which did not concurrently affect the number of neurons per field, indicating selective effects on neurite outgrowth. In contrast, more than half the chemicals which inhibited neurite outgrowth in human neural cultures did so at concentrations which concurrently decreased the number of neurons per field, indicating that effects on neurite outgrowth were secondary to cytotoxicity. Overall, these data demonstrate that the culture models performed differently in terms of reproducibility, dynamic range and sensitivity to neurite outgrowth inhibitors. While human neural

Comparative sensitivity of human and rat neural cultures to chemical-induced inhibition of neurite outgrowth

International Nuclear Information System (INIS)

Harrill, Joshua A.; Freudenrich, Theresa M.; Robinette, Brian L.; Mundy, William R.

2011-01-01

There is a need for rapid, efficient and cost-effective alternatives to traditional in vivo developmental neurotoxicity testing. In vitro cell culture models can recapitulate many of the key cellular processes of nervous system development, including neurite outgrowth, and may be used as screening tools to identify potential developmental neurotoxicants. The present study compared primary rat cortical cultures and human embryonic stem cell-derived neural cultures in terms of: 1) reproducibility of high content image analysis based neurite outgrowth measurements, 2) dynamic range of neurite outgrowth measurements and 3) sensitivity to chemicals which have been shown to inhibit neurite outgrowth. There was a large increase in neurite outgrowth between 2 and 24 h in both rat and human cultures. Image analysis data collected across multiple cultures demonstrated that neurite outgrowth measurements in rat cortical cultures were more reproducible and had higher dynamic range as compared to human neural cultures. Human neural cultures were more sensitive than rat cortical cultures to chemicals previously shown to inhibit neurite outgrowth. Parallel analysis of morphological (neurite count, neurite length) and cytotoxicity (neurons per field) measurements were used to detect selective effects on neurite outgrowth. All chemicals which inhibited neurite outgrowth in rat cortical cultures did so at concentrations which did not concurrently affect the number of neurons per field, indicating selective effects on neurite outgrowth. In contrast, more than half the chemicals which inhibited neurite outgrowth in human neural cultures did so at concentrations which concurrently decreased the number of neurons per field, indicating that effects on neurite outgrowth were secondary to cytotoxicity. Overall, these data demonstrate that the culture models performed differently in terms of reproducibility, dynamic range and sensitivity to neurite outgrowth inhibitors. While human neural

Antagonism of immunostimulatory CpG-oligodeoxynucleotides by quinacrine, chloroquine, and structurally related compounds.

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Macfarlane, D E; Manzel, L

1998-02-01

Phosphorothioate oligodeoxynucleotides containing CpG (CpG-ODN) activate immune responses. We report that quinacrine, chloroquine, and structurally related compounds completely inhibit the antiapoptotic effect of CpG-ODN on WEHI 231 murine B lymphoma cells and inhibit CpG-ODN-induced secretion of IL-6 by WEHI 231. They also inhibit IL-6 synthesis and thymidine uptake by human unfractionated PBMC induced by CpG-ODN. The compounds did not inhibit LPS-induced responses. Half-maximal inhibition required 10 nM quinacrine or 100 nM chloroquine. Inhibition was noncompetitive with respect to CpG-ODN. Quinine, quinidine, and primaquine were much less powerful. Quinacrine was effective even when added after the CpG-ODN. Near-toxic concentrations of ammonia plus bafilomycin A1 (used to inhibit vesicular acidification) did not reduce the efficacy of the quinacrine, but the effects of both quinacrine and chloroquine were enhanced by inhibition of the multidrug resistance efflux pump by verapamil. Agents that bind to DNA, including propidium iodide, Hoechst dye 33258, and coralyne chloride did not inhibit CpG-ODN effect, nor did 4-bromophenacyl bromide, an inhibitor of phospholipase A2. Examination of the structure-activity relationship of seventy 4-aminoquinoline and 9-aminoacridine analogues reveals that increased activity was conferred by bulky hydrophobic substituents on positions 2 and 6 of the quinoline nucleus. No correlation was found between published antimalarial activity and ability to block CpG-ODN-induced effects. These results are discussed in the light of the ability of quinacrine and chloroquine to induce remission of rheumatoid arthritis and lupus erythematosus.

Phenethyl isothiocyanate inhibits growth of human chronic myeloid leukemia K562 cells via reactive oxygen species generation and caspases.

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Wang, Yating; Wei, Sixi; Wang, Jishi; Fang, Qin; Chai, Qixiang

2014-07-01

Phenethyl isothiocyanate (PEITC), a potential cancer chemopreventive constituent of cruciferous vegetables, including watercress, has been reported to inhibit cancer cell growth by arresting the cell cycle and inducing apoptosis in various human cancer cell models. However, the role of PEITC in the inhibition of human chronic myeloid leukemia (CML) K562 cell growth and its underlying mechanisms have yet to be elucidated. In the present study, PEITC was found to induce cell death through the induction of reactive oxygen species (ROS) stress and oxidative damage. Heme oxygenase‑1 (HO‑1), which participates in the development of numerous tumors and the sensitivity of these tumors to chemotherapeutic drugs, plays a protective role by modulating oxidative injury. Therefore, the present study assessed the inhibitory effect of PEITC on K562 cells and whether HO‑1 facilitated cell apoptosis and ROS generation. PEITC was found to suppress cell growth and cause apoptosis by promoting Fas and Fas ligand expression, increasing ROS generation and by the successive release of cytochrome c as well as the activation of caspase‑9 and caspase‑3. PEITC was also combined with the HO‑1 inhibitor zinc protoporphyrin IX and the inducer hemin to assess whether HO‑1 determines cell survival and ROS generation. The results of the present study suggest that PEITC may be a potential anti‑tumor compound for CML therapy, and that HO‑1 has a critical function in PEITC‑induced apoptosis and ROS generation.

Inhibition selectivity of grapefruit juice components on human cytochromes P450.

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Tassaneeyakul, W; Guo, L Q; Fukuda, K; Ohta, T; Yamazoe, Y

2000-06-15

Five compounds including furanocoumarin monomers (bergamottin, 6', 7'-dihydroxybergamottin (DHB)), furanocoumarin dimers (4-¿¿6-hydroxy-71-¿(1-hydroxy-1-methyl)ethyl-4-methyl-6-(7-oxo-7H- furo¿3,2-g1benzopyran-4-yl)-4-hexenyl]oxy]-3,7-dimethyl- 2-octenyl]oxy]-7H-furo[3,2-g]¿1benzopyran-7-one (GF-I-1) and 4-¿¿6-hydroxy-7¿¿4-methyl-1-(1-methylethenyl)-6-(7-oxo-7H-furo¿3, 2-g1benzopyran-4-yl)-4-hexenylŏxy-3, 7-dimethyl-2-octenylŏxy-7H-furo¿3,2-g1benzopyran-7-one (GF-I-4)), and a sesquiterpene nootkatone have been isolated from grapefruit juice and screened for their inhibitory effects toward human cytochrome P450 (P450) forms using selective substrate probes. Addition of ethyl acetate extract of grapefruit juice into an incubation mixture resulted in decreased activities of CYP3A4, CYP1A2, CYP2C9, and CYP2D6. All four furanocoumarins clearly inhibited CYP3A4-catalyzed nifedipine oxidation in concentration- and time-dependent manners, suggesting that these compounds are mechanism-based inhibitors of CYP3A4. Of the furanocoumarins investigated, furanocoumarin dimers, GF-I-1 and GF-I-4, were the most potent inhibitors of CYP3A4. Inhibitor concentration required for half-maximal rate of inactivation (K(I)) values for bergamottin, DHB, GF-I-1, and GF-I-4 were calculated, respectively, as 40.00, 5. 56, 0.31, and 0.13 microM, whereas similar values were observed on their inactivation rate constant at infinite concentration of inhibitor (k(inact), 0.05-0.08 min(-1)). Apparent selectivity toward CYP3A4 does occur with the furanocoumarin dimers. In contrast, bergamottin showed rather stronger inhibitory effect on CYP1A2, CYP2C9, CYP2C19, and CYP2D6 than on CYP3A4. DHB inhibited CYP3A4 and CYP1A2 activities at nearly equivalent potencies. Among P450 forms investigated, CYP2E1 was the least sensitive to the inhibitory effect of furanocoumarin components. A sesquiterpene nootkatone has no significant effect on P450 activities investigated except for CYP2A6 and CYP2C19

The proteolytically stable peptidomimetic Pam-(Lys-βNSpe)6-NH2 selectively inhibits human neutrophil activation via formyl peptide receptor 2.

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Skovbakke, Sarah Line; Heegaard, Peter M H; Larsen, Camilla J; Franzyk, Henrik; Forsman, Huamei; Dahlgren, Claes

2015-01-15

Immunomodulatory host defense peptides (HDPs) are considered to be lead compounds for novel anti-sepsis and anti-inflammatory agents. However, development of drugs based on HDPs has been hampered by problems with toxicity and low bioavailability due to in vivo proteolysis. Here, a subclass of proteolytically stable HDP mimics consisting of lipidated α-peptide/β-peptoid oligomers was investigated for their effect on neutrophil function. The most promising compound, Pam-(Lys-βNSpe)6-NH2, was shown to inhibit formyl peptide receptor 2 (FPR2) agonist-induced neutrophil granule mobilization and release of reactive oxygen species. The potency of Pam-(Lys-βNSpe)6-NH2 was comparable to that of PBP10, the most potent FPR2-selective inhibitor known. The immunomodulatory effects of structural analogs of Pam-(Lys-βNSpe)6-NH2 emphasized the importance of both the lipid and peptidomimetic parts. By using imaging flow cytometry in primary neutrophils and FPR-transfected cell lines, we found that a fluorescently labeled analog of Pam-(Lys-βNSpe)6-NH2 interacted selectively with FPR2. Furthermore, the interaction between Pam-(Lys-βNSpe)6-NH2 and FPR2 was found to prevent binding of the FPR2-specific activating peptide agonist Cy5-WKYMWM, while the binding of an FPR1-selective agonist was not inhibited. To our knowledge, Pam-(Lys-βNSpe)6-NH2 is the first HDP mimic found to inhibit activation of human neutrophils via direct interaction with FPR2. Hence, we consider Pam-(Lys-βNSpe)6-NH2 to be a convenient tool in the further dissection of the role of FPR2 in inflammation and homeostasis as well as for investigation of the importance of neutrophil stimulation in anti-infective therapy involving HDPs. Copyright © 2014 Elsevier Inc. All rights reserved.

Potent inhibition of human neutrophil activations by bractelactone, a novel chalcone from Fissistigma bracteolatum

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Wu, Yang-Chang [Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Graduate Institute of Integrated Medicine, College of Chinese Medicine, China Medical University, Taichung 404, Taiwan (China); Sureshbabu, Munisamy; Fang, Yao-Ching; Wu, Yi-Hsiu [Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan (China); Lan, Yu-Hsuan [School of Pharmacy, China Medical University, Taichung 404, Taiwan (China); Chang, Fang-Rong [Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Chang, Ya-Wen [Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan (China); Hwang, Tsong-Long, E-mail: htl@mail.cgu.edu.tw [Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan (China); Chinese Herbal Medicine Research Team, Healthy Aging Research Center, Chang Gung University, Kweishan, Taoyuan 333, Taiwan (China)

2013-02-01

Fissistigma bracteolatum is widely used in traditional medicine to treat inflammatory diseases. However, its active components and mechanisms of action remain unclear. In this study, (3Z)-6,7-dihydroxy-4-methoxy-3-(phenylmethylidene)-5-(3-phenylpropanoyl) -1-benzofuran-2(3H) (bractelactone), a novel chalcone from F. bracteolatum, showed potent inhibitory effects against superoxide anion (O{sub 2}{sup ·−}) production, elastase release, and CD11b expression in formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-induced human neutrophils. However, bractelactone showed only weak inhibition of phorbol myristate acetate-caused O{sub 2}{sup ·−} production. The peak cytosolic calcium concentration ([Ca{sup 2+}]{sub i}) was unaltered by bractelactone in FMLP-induced neutrophils, but the decay time of [Ca{sup 2+}]{sub i} was significantly shortened. In a calcium-free solution, changes in [Ca{sup 2+}]{sub i} caused by the addition of extracellular Ca{sup 2+} were inhibited by bractelactone in FMLP-activated cells. In addition, bractelactone did not alter the phosphorylation of p38 MAPK, ERK, JNK, or AKT or the concentration of cAMP. These results suggest that bractelactone selectively inhibits store-operated calcium entry (SOCE). In agreement with this concept, bractelactone suppressed sustained [Ca{sup 2+}]{sub i} changes in thapsigargin-activated neutrophils. Furthermore, bractelactone did not alter FMLP-induced formation of inositol 1,4,5-triphosphate. Taken together, our results demonstrate that the anti-inflammatory effects of bractelactone, an active ingredient of F. bracteolatum, in human neutrophils are through the selective inhibition of SOCE. Highlights: ► Bractelactone isolated from Fissistigma bracteolatum. ► Bractelactone inhibited FMLP-induced human neutrophil activations. ► Bractelactone had no effect on IP3 formation. ► Bractelactone did not alter MAPKs, AKT, and cAMP pathways. ► Bractelactone inhibited store-operated calcium entry.

Effects of Intermediates between Vitamins K2 and K3 on Mammalian DNA Polymerase Inhibition and Anti-Inflammatory Activity

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Takeshi Azuma

2011-02-01

Full Text Available Previously, we reported that vitamin K3 (VK3, but not VK1 or VK2 (=MK-4, inhibits the activity of human DNA polymerase γ (pol γ. In this study, we chemically synthesized three intermediate compounds between VK2 and VK3, namely MK-3, MK-2 and MK-1, and investigated the inhibitory effects of all five compounds on the activity of mammalian pols. Among these compounds, MK-2 was the strongest inhibitor of mammalian pols α, κ and λ, which belong to the B, Y and X families of pols, respectively; whereas VK3 was the strongest inhibitor of human pol γ, an A-family pol. MK-2 potently inhibited the activity of all animal species of pol tested, and its inhibitory effect on pol λ activity was the strongest with an IC50 value of 24.6 μM. However, MK-2 did not affect the activity of plant or prokaryotic pols, or that of other DNA metabolic enzymes such as primase of pol α, RNA polymerase, polynucleotide kinase or deoxyribonuclease I. Because we previously found a positive relationship between pol λ inhibition and anti-inflammatory action, we examined whether these compounds could inhibit inflammatory responses. Among the five compounds tested, MK-2 caused the greatest reduction in 12-O-tetradecanoylphorbol-13-acetate (TPA-induced acute inflammation in mouse ear. In addition, in a cell culture system using mouse macrophages, MK-2 displayed the strongest suppression of the production of tumor necrosis factor (TNF-α induced by lipopolysaccharide (LPS. Moreover, MK-2 was found to inhibit the action of nuclear factor (NF-κB. In an in vivo mouse model of LPS-evoked acute inflammation, intraperitoneal injection of MK-2 in mice led to suppression of TNF-α production in serum. In conclusion, this study has identified VK2 and VK3 intermediates, such as MK-2, that are promising anti-inflammatory candidates.

The psychoactive compound of Cannabis sativa, Δ(9)-tetrahydrocannabinol (THC) inhibits the human trophoblast cell turnover.

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Costa, M A; Fonseca, B M; Marques, F; Teixeira, N A; Correia-da-Silva, G

2015-08-06

The noxious effects of cannabis consumption for fertility and pregnancy outcome are recognized for years. Its consumption during gestation is associated with alterations in foetal growth, low birth weight and preterm labor. The main psychoactive molecule of cannabis, Δ(9)-tetrahydrocannabinol (THC) impairs the production of reproductive hormones and is also able to cross the placenta barrier. However, its effect on the main placental cells, the trophoblasts, are unknown. Actually, the role of THC in cell survival/death of primary human cytotrophoblasts (CTs) and syncytiotrophoblasts (STs) and in the syncytialization process remains to be explored. Here, we show that THC has a dual effect, enhancing MTT metabolism at low concentrations, whereas higher doses decreased cell viability, on both trophoblast phenotypes, though the effects on STs were more evident. THC also diminished the generation of oxidative and nitrative stress and the oxidized form of glutathione, whereas the reduced form of this tripeptide was increased, suggesting that THC prevents ST cell death due to an antioxidant effect. Moreover, this compound enhanced the mitochondrial function of STs, as observed by the increased MTT metabolism and intracellular ATP levels. These effects were independent of cannabinoid receptors activation. Besides, THC impaired CT differentiation into STs, since it decreased the expression of biochemical and morphological biomarkers of syncytialization, through a cannabinoid receptor-dependent mechanism. Together, these results suggest that THC interferes with trophoblast turnover, preventing trophoblast cell death and differentiation, and contribute to disclose the cellular mechanisms that lead to pregnancy complications in women that consume cannabis-derived drugs during gestation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Nickel compounds induce histone ubiquitination by inhibiting histone deubiquitinating enzyme activity

International Nuclear Information System (INIS)

Ke Qingdong; Ellen, Thomas P.; Costa, Max

2008-01-01

Nickel (Ni) compounds are known carcinogens but underlying mechanisms are not clear. Epigenetic changes are likely to play an important role in nickel ion carcinogenesis. Previous studies have shown epigenetic effects of nickel ions, including the loss of histone acetylation and a pronounced increase in dimethylated H3K9 in nickel-exposed cells. In this study, we demonstrated that both water-soluble and insoluble nickel compounds induce histone ubiquitination (uH2A and uH2B) in a variety of cell lines. Investigations of the mechanism by which nickel increases histone ubiquitination in cells reveal that nickel does not affect cellular levels of the substrates of this modification, i.e., ubiquitin, histones, and other non-histone ubiquitinated proteins. In vitro ubiquitination and deubiquitination assays have been developed to further investigate possible effects of nickel on enzymes responsible for histone ubiquitination. Results from the in vitro assays demonstrate that the presence of nickel did not affect the levels of ubiquitinated histones in the ubiquitinating assay. Instead, the addition of nickel significantly prevents loss of uH2A and uH2B in the deubiquitinating assay, suggesting that nickel-induced histone ubiquitination is the result of inhibition of (a) putative deubiquitinating enzyme(s). Additional supporting evidence comes from the comparison of the response to nickel ions with a known deubiquitinating enzyme inhibitor, iodoacetamide (IAA). This study is the first to demonstrate such effects of nickel ions on histone ubiquitination. It also sheds light on the possible mechanisms involved in altering the steady state of this modification. The study provides further evidence that supports the notion that nickel ions alter epigenetic homeostasis in cells, which may lead to altered programs of gene expression and carcinogenesis

Pyrazole compound BPR1P0034 with potent and selective anti-influenza virus activity

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Yeh Jiann-Yih

2010-02-01

Full Text Available Abstract Background Influenza viruses are a major cause of morbidity and mortality around the world. More recently, a swine-origin influenza A (H1N1 virus that is spreading via human-to-human transmission has become a serious public concern. Although vaccination is the primary strategy for preventing infections, influenza antiviral drugs play an important role in a comprehensive approach to controlling illness and transmission. In addition, a search for influenza-inhibiting drugs is particularly important in the face of high rate of emergence of influenza strains resistant to several existing influenza antivirals. Methods We searched for novel anti-influenza inhibitors using a cell-based neutralization (inhibition of virus-induced cytopathic effect assay. After screening 20,800 randomly selected compounds from a library from ChemDiv, Inc., we found that BPR1P0034 has sub-micromolar antiviral activity. The compound was resynthesized in five steps by conventional chemical techniques. Lead optimization and a structure-activity analysis were used to improve potency. Time-of-addition assay was performed to target an event in the virus life cycle. Results The 50% effective inhibitory concentration (IC50 of BPR1P0034 was 0.42 ± 0.11 μM, when measured with a plaque reduction assay. Viral protein and RNA synthesis of A/WSN/33 (H1N1 was inhibited by BPR1P0034 and the virus-induced cytopathic effects were thus significantly reduced. BPR1P0034 exhibited broad inhibition spectrum for influenza viruses but showed no antiviral effect for enteroviruses and echovirus 9. In a time-of-addition assay, in which the compound was added at different stages along the viral replication cycle (such as at adsorption or after adsorption, its antiviral activity was more efficient in cells treated with the test compound between 0 and 2 h, right after viral infection, implying that an early step of viral replication might be the target of the compound. These results suggest

Mechanisms of inhibition of DNA replication by ultraviolet light in normal human and xeroderma pigmentosum fibroblasts

International Nuclear Information System (INIS)

Kaufmann, W.K.; Cleaver, J.E.

1981-01-01

The inhibition of DNA replication in ultraviolet-irradiated human fibroblasts was characterized by quantitative analysis of radiation-induced alterations in the steady-state distribution of sizes of pulse-labeled, nascent DNA. Low, noncytotoxic fluences rapidly produced an inhibition of DNA synthesis in half-replicon-size replication intermediates. With time, the inhibition produced by low fluences spread progressively to include multi-replicon-size intermediates. The results indicate that ultraviolet radiation inhibits the initiation of DNA synthesis in replicons. Higher cytotoxic fluences inhibited DNA synthesis in operating replicons. Xeroderma pigmentosum fibroblasts with deficiencies in DNA excision repair exhibited an inhibition of replicon initiation after low radiation fluences, indicating the effect was not solely dependent upon operation of the nucleotidyl excision repair pathway. Owing to their inability to remove pyrimidine dimers ahead of DNA growing points, the repair-deficient cells also were more sensitive than normal cells to the ultraviolet-induced inhibition of chain elongation. Xeroderma pigmentosum cells belonging to the variant class were even more sensitive to inhibition of chain elongation despite their ability to remove pyrimidine dimers. The analysis suggested that normal and repair-deficient human fibroblasts either are able to rapidly bypass certain dimers or these dimers are not recognized by the chain elongation machinery. (author)

An evaluation of the RNase H inhibitory effects of Vietnamese medicinal plant extracts and natural compounds.

Science.gov (United States)

Tai, Bui Huu; Nhut, Nguyen Duy; Nhiem, Nguyen Xuan; Quang, Tran Hong; Thanh Ngan, Nguyen Thi; Thuy Luyen, Bui Thi; Huong, Tran Thu; Wilson, Jennifer; Beutler, John A; Ban, Ninh Khac; Cuong, Nguyen Manh; Kim, Young Ho

2011-10-01

Acquired immune deficiency syndrome (AIDS) is a severe pandemic disease especially prevalent in poor and developing countries. Thus, developing specific, potent antiviral drugs that restrain infection by human immunodeficiency virus type 1 (HIV-1), a major cause of AIDS, remains an urgent priority. This study evaluated 32 extracts and 23 compounds from Vietnamese medicinal plants for their inhibitory effects against HIV-1 ribonuclease H (RNase H) and their role in reversing the cytopathic effects of HIV. The plants were air-dried and extracted in different solvent systems to produce plant extracts. Natural compounds were obtained as previously published. Samples were screened for RNase H inhibition followed by a cytopathic assay. Data were analyzed using the Microsoft Excel. At 50 μg/mL, 11 plant extracts and five compounds inhibited over 90% of RNase H enzymatic activity. Methanol extracts from Phyllanthus reticulatus and Aglaia aphanamixis leaves inhibited RNase H activity by 99 and 98%, respectively, whereas four extracts showed modest protection against the cytopathic effects of HIV. The screening results demonstrated that the butanol (BuOH) extract of Celastrus orbiculata leaves, methanol (MeOH) extracts of Glycosmis stenocarpa stems, Eurya ciliata leaves, and especially P. reticulatus leaves showed potential RNase H inhibition and protection against the viral cytopathic effects of HIV-1. Further chemical investigations should be carried out to find the active components of these extracts and compounds as potential anti-HIV drug candidates.

Estrogen receptor beta signaling inhibits PDGF induced human airway smooth muscle proliferation.

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Ambhore, Nilesh Sudhakar; Katragadda, Rathnavali; Raju Kalidhindi, Rama Satyanarayana; Thompson, Michael A; Pabelick, Christina M; Prakash, Y S; Sathish, Venkatachalem

2018-04-20

Airway smooth muscle (ASM) cell hyperplasia driven by persistent inflammation is a hallmark feature of remodeling in asthma. Sex steroid signaling in the lungs is of considerable interest, given epidemiological data showing more asthma in pre-menopausal women and aging men. Our previous studies demonstrated that estrogen receptor (ER) expression increases in asthmatic human ASM; however, very limited data are available regarding differential roles of ERα vs. ERβ isoforms in human ASM cell proliferation. In this study, we evaluated the effect of selective ERα and ERβ modulators on platelet-derived growth factor (PDGF)-stimulated ASM proliferation and the mechanisms involved. Asthmatic and non-asthmatic primary human ASM cells were treated with PDGF, 17β-estradiol, ERα-agonist and/or ERβ-agonist and/or G-protein-coupled estrogen receptor 30 (GPR30/GPER) agonist and proliferation was measured using MTT and CyQuant assays followed by cell cycle analysis. Transfection of small interfering RNA (siRNA) ERα and ERβ significantly altered the human ASM proliferation. The specificity of siRNA transfection was confirmed by Western blot analysis. Gene and protein expression of cell cycle-related antigens (PCNA and Ki67) and C/EBP were measured by RT-PCR and Western analysis, along with cell signaling proteins. PDGF significantly increased ASM proliferation in non-asthmatic and asthmatic cells. Treatment with PPT showed no significant effect on PDGF-induced proliferation, whereas WAY interestingly suppressed proliferation via inhibition of ERK1/2, Akt, and p38 signaling. PDGF-induced gene expression of PCNA, Ki67 and C/EBP in human ASM was significantly lower in cells pre-treated with WAY. Furthermore, WAY also inhibited PDGF-activated PCNA, C/EBP, cyclin-D1, and cyclin-E. Overall, we demonstrate ER isoform-specific signaling in the context of ASM proliferation. Activation of ERβ can diminish remodeling in human ASM by inhibiting pro-proliferative signaling pathways

Nitrite and nitroso compounds can serve as specific catalase inhibitors.

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Titov, Vladimir Yu; Osipov, Anatoly N

2017-03-01

We present evidence that nitrite and nitrosothiols, nitrosoamines and non-heme dinitrosyl iron complexes can reversibly inhibit catalase with equal effectiveness. Catalase activity was evaluated by the permanganatometric and calorimetric assays. This inhibition is not the result of chemical transformations of these compounds to a single inhibitor, as well as it is not the result of NO release from these substances (as NO traps have no effect on the extent of inhibition). It was found that chloride and bromide in concentration above 80 mM and thiocyanate in concentration above 20 μM enhance catalase inhibition by nitrite and the nitroso compounds more than 100 times. The inhibition degree in this case is comparable with that induced by azide. We propose that the direct catalase inhibitor is a positively charged NO-group. This group acquires a positive charge in the active center of enzyme by interaction of nitrite or nitroso compounds with some enzyme groups. Halides and thiocyanate protect the NO + group from hydration and thus increase its inhibition effect. It is probable that a comparatively low chloride concentration in many cells is the main factor to protect catalase from inhibition by nitrite and nitroso compounds.

Inhibition of Nitzschia ovalis biofilm settlement by a bacterial bioactive compound through alteration of EPS and epiphytic bacteria

Directory of Open Access Journals (Sweden)

Claudia D. Infante

2018-05-01

Full Text Available Background: Marine ecosystems contain benthic microalgae and bacterial species that are capable of secreting extracellular polymeric substances (EPS, suggesting that settlement of these microorganisms can occur on submerged surfaces, a key part of the first stage of biofouling. Currently, anti-fouling treatments that help control this phenomenon involve the use of biocides or antifouling paints that contain heavy metals, which over a long period of exposure can spread to the environment. The bacterium Alteromonas sp. Ni1-LEM has an inhibitory effect on the adhesion of Nitzschia ovalis, an abundant diatom found on submerged surfaces. Results: We evaluated the effect of the bioactive compound secreted by this bacterium on the EPS of biofilms and associated epiphytic bacteria. Three methods of EPS extraction were evaluated to determine the most appropriate and efficient methodology based on the presence of soluble EPS and the total protein and carbohydrate concentrations. Microalgae were cultured with the bacterial compound to evaluate its effect on EPS secretion and variations in its protein and carbohydrate concentrations. An effect of the bacterial supernatant on EPS was observed by assessing biofilm formation and changes in the concentration of proteins and carbohydrates present in the biofilm. Conclusions: These results indicate that a possible mechanism for regulating biofouling could be through alteration of biofilm EPS and alteration of the epiphytic bacterial community associated with the microalga.How to cite: Infante, C.D., Castillo, F., Pérez, V., et al. Inhibition of Nitzschia ovalis biofilm settlement by a bacterial bioactive compound through alteration of EPS and epiphytic bacteria. Electron J Biotechnol 2018;33 https://doi.org/10.1016/j.ejbt.2018.03.002. Keywords: Anti-fouling, Benthic microalgae, Biofilm, Biofouling, Epiphytic bacterial community, EPS, Marine ecosystems, Metagenomic, Nitzschia ovalis, Settlement inhibition

Inhibition of angiogenesis: a novel antitumor mechanism of the herbal compound arctigenin.

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Gu, Yuan; Scheuer, Claudia; Feng, Dilu; Menger, Michael D; Laschke, Matthias W

2013-09-01

Arctigenin, a functional ingredient of several traditional Chinese herbs, has been reported to have potential antitumor activity. However, its mechanisms of action are still not well elucidated. Because the establishment and metastatic spread of tumors is crucially dependent on angiogenesis, here we investigated whether arctigenin inhibits tumor growth by disturbing blood vessel formation. For this purpose, human dermal microvascular endothelial cells were exposed to different arctigenin doses to study their viability, proliferation, protein expression, migration, and tube formation compared with vehicle-treated controls. In addition, arctigenin action on vascular sprouting was analyzed in an aortic ring assay. Furthermore, we studied direct arctigenin effects on CT26.WT colon carcinoma cells. Spheroids of these tumor cells were transplanted into the dorsal skinfold chamber of arctigenin-treated and vehicle-treated BALB/c mice for the in-vivo analysis of tumor vascularization and growth by intravital fluorescence microscopy, histology, and immunohistochemistry. We found that noncytotoxic doses of arctigenin dose dependently reduced the proliferation of human dermal microvascular endothelial cells without affecting their migratory and tube-forming capacity. Arctigenin treatment also resulted in a decreased cellular expression of phosphorylated serine/threonine protein kinase AKT, vascular endothelial growth factor receptor 2, and proliferating cell nuclear antigen and inhibited vascular sprouting from aortic rings. In addition, proliferation, but not secretion of vascular endothelial growth factor, was decreased in arctigenin-treated tumor cells. Finally, arctigenin suppressed the vascularization and growth of engrafting CT26.WT tumors in the dorsal skinfold chamber model. Taken together, these results show for the first time an antiangiogenic action of arctigenin, which may contribute considerably toward its antitumor activity.

Identification of pyrogallol as an antiproliferative compound present in extracts from the medicinal plant Emblica officinalis: effects on in vitro cell growth of human tumor cell lines.

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Khan, Mahmud Tareq Hassan; Lampronti, Ilaria; Martello, Dino; Bianchi, Nicoletta; Jabbar, Shaila; Choudhuri, Mohammad Shahabuddin Kabir; Datta, Bidduyt Kanti; Gambari, Roberto

2002-07-01

In this study we compared the in vitro antiproliferative activity of extracts from medicinal plants toward human tumor cell lines, including human erythromyeloid K562, B-lymphoid Raji, T-lymphoid Jurkat, erythroleukemic HEL cell lines. Extracts from Emblica officinalis were the most active in inhibiting in vitro cell proliferation, after comparison to those from Terminalia arjuna, Aphanamixis polystachya, Oroxylum indicum, Cuscuta reflexa, Aegle marmelos, Saraca asoka, Rumex maritimus, Lagerstroemia speciosa, Red Sandalwood. Emblica officinalis extracts have been studied previously, due to their hepatoprotective, antioxidant, antifungal, antimicrobial and anti-inflammatory medicinal activities. Gas chromatography/mass spectrometry analyses allowed to identify pyrogallol as the common compound present both in unfractionated and n-butanol fraction of Emblica officinalis extracts. Antiproliferative effects of pyrogallol were therefore determined on human tumor cell lines thus identifying pyrogallol as an active component of Emblica officinalis extracts.

Prediction of Human Intestinal Absorption of Compounds Using Artificial Intelligence Techniques.

Science.gov (United States)

Kumar, Rajnish; Sharma, Anju; Siddiqui, Mohammed Haris; Tiwari, Rajesh Kumar

2017-01-01

Information about Pharmacokinetics of compounds is an essential component of drug design and development. Modeling the pharmacokinetic properties require identification of the factors effecting absorption, distribution, metabolism and excretion of compounds. There have been continuous attempts in the prediction of intestinal absorption of compounds using various Artificial intelligence methods in the effort to reduce the attrition rate of drug candidates entering to preclinical and clinical trials. Currently, there are large numbers of individual predictive models available for absorption using machine learning approaches. Six Artificial intelligence methods namely, Support vector machine, k- nearest neighbor, Probabilistic neural network, Artificial neural network, Partial least square and Linear discriminant analysis were used for prediction of absorption of compounds. Prediction accuracy of Support vector machine, k- nearest neighbor, Probabilistic neural network, Artificial neural network, Partial least square and Linear discriminant analysis for prediction of intestinal absorption of compounds was found to be 91.54%, 88.33%, 84.30%, 86.51%, 79.07% and 80.08% respectively. Comparative analysis of all the six prediction models suggested that Support vector machine with Radial basis function based kernel is comparatively better for binary classification of compounds using human intestinal absorption and may be useful at preliminary stages of drug design and development. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Inhibition of histamine and eicosanoid release from dispersed human lung cells in vitro by quinotolast.

Science.gov (United States)

Okayama, Y; Hiroi, J; Lau, L C; Church, M K

1995-12-01

We have examined the effects of a new anti-allergic drug, quinotolast [sodium 5-(4-oxo-1-phenoxy-4H-quinolizine-3-carboxamido) yetrazolate monohydrate], in inhibiting the release of histamine and the generation of leukotriene (LT) C4 and prostaglandin (PG) D2 from dispersed human lung cells and compared this with those of its active metabolite in the rat, hydroxy quinotolast, and reference drugs, tranilast and sodium cromoglycate (SCG). Quinotolast in the concentration range of 1-100 micrograms/ml inhibited histamine and LTC4 release in a concentration-dependent manner. The inhibitory effect of quinotolast on histamine release from dispersed lung cells was largely independent of the preincubation period, no tachyphylaxis being observed. Hydroxy quinotolast and tranilast showed a weak inhibition of histamine release only when the drugs were added to the cells simultaneously with anti-IgE challenge. Quinotolast, 100 micrograms/ml, and SCG, 1 mM, significantly inhibited PGD2 and LTC4 release. Quinotolast inhibited PGD2 release by 100% and LTC4 release by 54%, whereas SCG inhibited PDG2 release by 33% and LTC4 release by 100%. No cross-tachyphylaxis between quinotolast and SCG was observed. The results demonstrated that quinotolast showed a significant inhibition of inflammatory mediators from human dispersed lung cells, suggesting that quinotolast is a good candidate for a clinical anti-allergic drug.

Effects of the novel anti-inflammatory compounds, N-[2-(cyclohexyloxy)-4-nitrophenyl] methanesulphonamide (NS-398) and 5-methanesulphonamido-6-(2,4-difluorothio-phenyl)-1-inda none (L-745,337), on the cyclo-oxygenase activity of human blood prostaglandin endoperoxide synthases.

Science.gov (United States)

Panara, M R; Greco, A; Santini, G; Sciulli, M G; Rotondo, M T; Padovano, R; di Giamberardino, M; Cipollone, F; Cuccurullo, F; Patrono, C

1995-11-01

1. We have evaluated the selectivity of ketoprofen and two novel nonsteroidal anti-inflammatory drugs, N-[2-(cyclohexyloxy)-4-nitrophenyl]methanesulphonamide (NS-398) and 5-methanesulphonamido-6-(2,4-difluorothiophenyl)-1-indano ne (L-745,337), in inhibiting the cyclo-oxygenase activity of prostaglandin endoperoxide synthase-2 (PGHS-2) vs PGHS-1 in human blood monocytes and platelets, respectively. 2. Heparinized whole blood samples were drawn from healthy volunteers pretreated with aspirin, 300 mg 48 h before sampling, to suppress the activity of platelet PGHS-1 and incubated at 37 degrees C for 24 h with increasing concentrations of the test compounds in the presence of lipopolysaccharide (LPS, 10 micrograms ml-1). Immunoreactive PGE2 levels were measured in plasma by a specific radioimmunoassay as an index of the cyclo-oxygenase activity of LPS-induced monocyte PGHS-2. 3. The effects of the same inhibitors on platelet PGHS-1 activity were assessed by allowing whole blood samples, drawn from the same subjects in aspirin-free periods, to clot at 37 degrees C for 1 h in the presence of the compounds and measuring immunoreactive thromboxane B2 (TXB2) levels in serum by a specific radioimmunoassay. 4. Under these experimental conditions, ketoprofen enantioselectively inhibited the cyclo-oxygenase activity of both PGHS-1 and PGHS-2 with equal potency (IC50 ratio: approx. 0.5 for both enantiomers), while L-745,337 and NS-398 achieved selective inhibition of monocyte PGHS-2 (IC50 ratio: > 150). L-745,337 and NS-398 did not affect LPS-induced monocyte PGHS-2 biosynthesis to any detectable extent. 5. We conclude that L-745,337 and NS-398 are selective inhibitors of the cyclo-oxygenase activity of human monocyte PGHS-2. These compounds may provide adequate tools to test the contribution of this novel pathway of arachidonate metabolism to human inflammatory disease.

Accumulation of 19 environmental phenolic and xenobiotic heterocyclic aromatic compounds in human adipose tissue.

Science.gov (United States)

Wang, Lei; Asimakopoulos, Alexandros G; Kannan, Kurunthachalam

2015-05-01

The extensive use of environmental phenols (e.g., bisphenol A) and heterocyclic aromatic compounds (e.g., benzothiazole) in consumer products as well as widespread exposure of humans to these compounds have been well documented. Biomonitoring studies have used urinary measurements to assess exposures, based on the assumption that these chemicals are metabolized and eliminated in urine. Despite the fact that some of these chemicals are moderately lipophilic, the extent of their accumulation in adipose fat tissues has not been convincingly demonstrated. In this study, human adipose fat samples (N=20) collected from New York City, USA, were analyzed for the presence of environmental phenols, including bisphenol A (BPA), benzophenone-3 (BP-3), triclosan (TCS), and parabens, as well as heterocyclic aromatic compounds, including benzotriazole (BTR), benzothiazole (BTH), and their derivatives. BPA and TCS were frequently detected in adipose tissues at concentrations (geometric mean [GM]: 3.95ng/g wet wt for BPA and 7.21ng/g wet wt for TCS) similar to or below the values reported for human urine. High concentrations of BP-3 were found in human adipose tissues (GM: 43.4; maximum: 4940ng/g wet wt) and a positive correlation between BP-3 concentrations and donor's age was observed. The metabolite of parabens, p-hydroxybenzoic acid (p-HB), also was found at elevated levels (GM: 4160; max.: 17,400ng/g wet wt) and a positive correlation between donor's age and sum concentration of parabens and p-HB were found. The GM concentrations of BTR and BTH in human adipose tissues were below 1ng/g, although the methylated forms of BTR (i.e., TTR and XTR) and the hydrated form of BTH (i.e., 2-OH-BTH) were frequently detected in adipose samples, indicating widespread exposure to these compounds. Our results suggest that adipose tissue is an important repository for BP-3 and parabens, including p-HB, in the human body. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inhibition of rat, mouse, and human glutathione S-transferase by eugenol and its oxidation products

NARCIS (Netherlands)

Rompelberg, C.J.M.; Ploemen, J.H.T.M.; Jespersen, S.; Greef, J. van der; Verhagen, H.; Bladeren, P.J. van

1996-01-01

The irreversible and reversible inhibition of glutathione S-transferases (GSTs) by eugenol was studied in rat, mouse and man. Using liver cytosol of human, rat and mouse, species differences were found in the rate of irreversible inhibition of GSTs by eugenol in the presence of the enzyme

Isolation and characterization of an anticancer catechol compound from Semecarpus anacardium.

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Nair, P K Raveedran; Melnick, Steven J; Wnuk, Stanislaw F; Rapp, Magdalena; Escalon, Enrique; Ramachandran, Cheppail

2009-04-21

The fruits and seeds of Semecarpus anacardium are used widely for the treatment of human cancers and other diseases in the Ayurvedic and Sidda systems of medicine in India. The principal aim of this investigation was to isolate and characterize the anticancer compound from the kernel of Semecarpus anacardium nut. The bioactivity-tailored isolation and detailed chemical characterization were used to identify the active compound. Cytotoxicity, apoptosis, cell cycle arrest as well as synergism between the identified anticancer compound and doxorubicin in human tumor cell lines were analyzed. GC/MS, IR, proton NMR, carbon NMR and collisionally induced dissociation (CID) spectra analysis showed that the isolated active compound is 3-(8'(Z),11'(Z)-pentadecadienyl) catechol (SA-3C). SA-3C is cytotoxic to tumor cell lines with IC(50) values lower than doxorubicin and even multidrug resistant tumor cell lines were equally sensitive to SA-3C. SA-3C induced apoptosis in human leukemia cell lines in a dose-dependent manner and showed synergistic cytotoxicity with doxorubicin. The cell cycle arrest induced by SA-3C at S- and G(2)/M-phases correlated with inhibition of checkpoint kinases. SA-3C isolated from the kernel of Semecarpus anacardium can be developed as an important anticancer agent for single agent and/or multiagent cancer therapy.

Lipoxygenase and urease inhibition of extracts of polygonatum verticillatum rhizome: augmented by its isolated compound, santonin

International Nuclear Information System (INIS)

Khan, H.; Saeed, M.; Saeed, M.

2014-01-01

The present study was designed to explore the enzyme inhibitory profile of extracts of rhizome of Polygonatum verticillatum against lipoxygenase and urease. When tested against lipoxygenase, ethyl acetate fraction was found the most potent (IC50: 69 micro g/ml) and the overall IC50 values of different extracts ranged from 69-174 micro g/ml. In urease assay, n-butanol was the most potent fraction (IC50: 169 micro g/ml) while the overall IC50 values were in the range of 169-288 micro g/ml. Bioactivity guided chromatography led to the isolation of compound 1 which was characterized as santonin on the basis of various spectroscopic techniques. When santonin was tested against lipoxygenase and urease, it showed potent inhibition of lipoxygenase (IC50: 27.4 micro M) but did not attenuate the urease activity. Our findings provided strong evidence for the enzyme inhibitory profile of the extracts of P. verticillatum rhizome and its isolated compound. Thus results are consistent with the traditional use of the plant as an anti-inflammatory agent. (author)

The aryl hydrocarbon receptor ligand ITE inhibits TGFβ1-induced human myofibroblast differentiation.

Science.gov (United States)

Lehmann, Geniece M; Xi, Xia; Kulkarni, Ajit A; Olsen, Keith C; Pollock, Stephen J; Baglole, Carolyn J; Gupta, Shikha; Casey, Ann E; Huxlin, Krystel R; Sime, Patricia J; Feldon, Steven E; Phipps, Richard P

2011-04-01

Fibrosis can occur in any human tissue when the normal wound healing response is amplified. Such amplification results in fibroblast proliferation, myofibroblast differentiation, and excessive extracellular matrix deposition. Occurrence of these sequelae in organs such as the eye or lung can result in severe consequences to health. Unfortunately, medical treatment of fibrosis is limited by a lack of safe and effective therapies. These therapies may be developed by identifying agents that inhibit critical steps in fibrotic progression; one such step is myofibroblast differentiation triggered by transforming growth factor-β1 (TGFβ1). In this study, we demonstrate that TGFβ1-induced myofibroblast differentiation is blocked in human fibroblasts by a candidate endogenous aryl hydrocarbon receptor (AhR) ligand 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE). Our data show that ITE disrupts TGFβ1 signaling by inhibiting the nuclear translocation of Smad2/3/4. Although ITE functions as an AhR agonist, and biologically persistent AhR agonists, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin, cause severe toxic effects, ITE exhibits no toxicity. Interestingly, ITE effectively inhibits TGFβ1-driven myofibroblast differentiation in AhR(-/-) fibroblasts: Its ability to inhibit TGFβ1 signaling is AhR independent. As supported by the results of this study, the small molecule ITE inhibits myofibroblast differentiation and may be useful clinically as an antiscarring agent. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Virtual Dual inhibition of COX-2 / 5-LOX enzymes based on binding properties of alpha-amyrins, the anti-inflammatory compound as a promising anti-cancer drug

Science.gov (United States)

Ranjbar, Mohammad Mehdi; Assadolahi, Vahideh; Yazdani, Mohsen; Nikaein, Donya; Rashidieh, Behnam

2016-01-01

Hydro-alcoholic fruit extract of Cordia myxa was considerably effective on curing acute inflammation in mouse model. Previous studies suggested significant anti-inflammatory activities as well as potential anticancer agent of α-amyrins in seeds. Inhibition of Cyclooxygenase-2 (COX-2) and 5-Lipooxygenase (5-LOX) is significant in cancer prevention and therapeutics although this inhibition with chemo-drugs has its own side-effects. It is shown that these enzymes pathways are related to several cancers including colon, breast and lung cancer. This study was conducted based on Cordia species' α-amyrins as a safer natural anti-cancer compound for inhibition of COX-2 and 5-LOX enzymes by molecular docking. The X-ray crystal structure of COX2 / 5-LOX enzymes and α-amyrins was retrieved and energetically minimized respectively. The binding site and surface of enzymes were detected. Docking studies were performed by AutoDock 4.2 using Lamarckian genetic algorithm (LGA). Finally drug likeness, molecular pharmacokinetic properties and toxicity of α-amyrins was calculated. Molecular Docking revealed hydrogen and hydrophobic interactions between α-amyrins with both active sites of COX-2 and 5-LOX enzymes. Interestingly, it covalently bonded to Fe cofactor of 5-LOX enzyme and chelated this molecule. Base on binding energies (∆G) α-amyrin has more inhibitory effects on 5-LOX (-10.45 Kcal/mol) than COX-2 (-8.02 Kcal/mol). Analysis of molecular pharmacokinetic parameters suggested that α-amyrins complied with most sets of Lipinski's rules, and so it could be a suitable ligand for docking studies. Eventually, bioactivity score showed α-amyrins possess considerable biological activities as nuclear receptor, enzyme inhibitor, GPCR and protease inhibitor ligand. These results clearly demonstrate that α-amyrins could act as potential highly selective COX-/5-LOX inhibitor. Also, it is a safe compound in comparison with classical non-steroidal anti-inflammatory drugs (NSAIDs

Compounded effects of chlorinated ethene inhibition on ecological interactions and population abundance in a Dehalococcoides - Dehalobacter coculture.

Science.gov (United States)

Lai, Yenjung; Becker, Jennifer G

2013-02-05

The development of rational and effective engineered bioremediation approaches for sites contaminated with chlorinated solvents requires a fundamental understanding of the factors limiting the in situ activity of dehalorespiring bacteria. Frequently, multiple dehalorespiring bacteria are present at contaminated sites, particularly when bioaugmentation is applied. The ecological interactions between different dehalorespiring populations can-along with hydrodynamic and other environmental factors-affect their activity and thus the rates and extent of dehalorespiration. An integrated experimental and modeling approach was used to evaluate the ecological interactions between two hydrogenotrophic, dehalorespiring strains. A dual Monod model of dehalorespiration provided a good fit to the chlorinated ethene concentrations measured in a coculture of Dehalococcoides mccartyi 195 and Dehalobacter restrictus growing on tetrachloroethene (PCE) and excess H(2) in a continuous-flow reactor. Inhibition of dehalorespiration by chlorinated ethenes was previously observed in cultures containing Dehalococcoides or Dehalobacter strains. Therefore, inhibition coefficients were estimated for Dhc. mccartyi 195 and Dhb. restrictus. The inhibition effects of PCE and TCE on VC dechlorination by Dhc. mccartyi 195, and of VC on PCE and TCE dechlorination by Dhb. restrictus, were compounded when these strains were grown in coculture, and dehalorespiring population abundance and survival could be accurately predicted only by incorporating these complex interactions into the dual Monod model.

Meisoindigo, but not its core chemical structure indirubin, inhibits zebrafish interstitial leukocyte chemotactic migration.

Science.gov (United States)

Ye, Baixin; Xiong, Xiaoxing; Deng, Xu; Gu, Lijuan; Wang, Qiongyu; Zeng, Zhi; Gao, Xiang; Gao, Qingping; Wang, Yueying

2017-12-01

Inflammatory disease is a big threat to human health. Leukocyte chemotactic migration is required for efficient inflammatory response. Inhibition of leukocyte chemotactic migration to the inflammatory site has been shown to provide therapeutic targets for treating inflammatory diseases. Our study was designed to discover effective and safe compounds that can inhibit leukocyte chemotactic migration, thus providing possible novel therapeutic strategy for treating inflammatory diseases. In this study, we used transgenic zebrafish model (Tg:zlyz-EGFP line) to visualize the process of leukocyte chemotactic migration. Then, we used this model to screen the hit compound and evaluate its biological activity on leukocyte chemotactic migration. Furthermore, western blot analysis was performed to evaluate the effect of the hit compound on the AKT or ERK-mediated pathway, which plays an important role in leukocyte chemotactic migration. In this study, using zebrafish-based chemical screening, we identified that the hit compound meisoindigo (25 μM, 50 μM, 75 μM) can significantly inhibit zebrafish leukocyte chemotactic migration in a dose-dependent manner (p = 0.01, p = 0.0006, p migration (p = 0.43). Furthermore, our results unexpectedly showed that indirubin, the core structure of meisoindigo, had no significant effect on zebrafish leukocyte chemotactic migration (p = 0.6001). Additionally, our results revealed that meisoindigo exerts no effect on the Akt or Erk-mediated signalling pathway. Our results suggest that meisoindigo, but not indirubin, is effective for inhibiting leukocyte chemotactic migration, thus providing a potential therapeutic agent for treating inflammatory diseases.

Quantitative structure-activity analysis of acetylcholinesterase inhibition by oxono and thiono analogues of organophosphorus compounds. (Reannouncement with new availability information)

Energy Technology Data Exchange (ETDEWEB)

Maxwell, D.M.; Brecht, K.M.

1992-02-01

A comparison of the bimolecular rate constants (ki) for inhibition of electric eel acetylcholinesterase (AChE) by the oxono (i.e., P=O) and thiono (i.e., P=S) analogues of parathion, methylparathion, leptophos, fonofos, sarin, and soman revealed that the oxono/thiono ratios of ki values varied from 14 for soman to 1240 for parathion. Analysis of the relative importance of the dissociation equilibrium constant and the phosphorylation rate constant in producing this variation in ki values indicated that the oxono analogues had phosphorylation rate constant values that varied in a narrow range from 8- to 14-fold greater than their thiono counterparts, while the oxono/thiono ratios for dissociation constants varied widely from 1 for soman to 82 for fonofos. The lower affinities of thiono analogues for AChE probably resulted from differences in the hydrophobic binding of oxono and thiono analogues to the active site of AChE, inasmuch as the hydrophobicities (i.e., octanol/water partition coefficients) of thiono organophosphorus compounds were much greater than the hydrophobicities of their oxono analogues. Quantitative structure-activity analysis indicated that the hydrophobic effects of oxono and thiono moieties correlated with log ki for AChE inhibition to a greater extent (r2 = 0.79) than their electronic effects (r2 equal to or less than 0.48). These observations suggest that the differences in hydrophobicity of oxono and thiono analogues of organophosphorus compounds may be as important as their electronic differences in determining their effectiveness as AChE inhibitors. Acetylcholinesterase, soman (GD), structure-activity analysis inhibition, oxono analogues, thiono analogues.

Relevance of estrogenic and aromatase inhibiting effects of mixtures of xenoestrogens for human exposure

NARCIS (Netherlands)

van Meeuwen, J.A.

2008-01-01

BACKGROUND. Daily humans are exposed to various sources of estrogen-like compounds (xenoestrogens), such as food (naturally occurring, residues or contaminants), clothes and cosmetics. Non-governmental organisations give the impression that this causes adverse effects on human health and the

Enzyme Mechanism and Slow-Onset Inhibition of Plasmodium falciparum Enoyl-Acyl Carrier Protein Reductase by an Inorganic Complex

Science.gov (United States)

de Medeiros, Patrícia Soares de Maria; Ducati, Rodrigo Gay; Basso, Luiz Augusto; Santos, Diógenes Santiago; da Silva, Luiz Hildebrando Pereira

2011-01-01

Malaria continues to be a major cause of children's morbidity and mortality worldwide, causing nearly one million deaths annually. The human malaria parasite, Plasmodium falciparum, synthesizes fatty acids employing the Type II fatty acid biosynthesis system (FAS II), unlike humans that rely on the Type I (FAS I) pathway. The FAS II system elongates acyl fatty acid precursors of the cell membrane in Plasmodium. Enoyl reductase (ENR) enzyme is a member of the FAS II system. Here we present steady-state kinetics, pre-steady-state kinetics, and equilibrium fluorescence spectroscopy data that allowed proposal of P. falciparum ENR (PfENR) enzyme mechanism. Moreover, building on previous results, the present study also evaluates the PfENR inhibition by the pentacyano(isoniazid)ferrateII compound. This inorganic complex represents a new class of lead compounds for the development of antimalarial agents focused on the inhibition of PfENR. PMID:21603269

Ursolic acid inhibits superoxide production in activated neutrophils and attenuates trauma-hemorrhage shock-induced organ injury in rats.

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Tsong-Long Hwang

Full Text Available Neutrophil activation is associated with the development of organ injury after trauma-hemorrhagic shock. In the present study, ursolic acid inhibited the superoxide anion generation and elastase release in human neutrophils. Administration of ursolic acid attenuated trauma-hemorrhagic shock-induced hepatic and lung injuries in rats. In addition, administration of ursolic acid attenuated the hepatic malondialdehyde levels and reduced the plasma aspartate aminotransferase and alanine aminotransferase levels after trauma-hemorrhagic shock. In conclusion, ursolic acid, a bioactive natural compound, inhibits superoxide anion generation and elastase release in human neutrophils and ameliorates trauma-hemorrhagic shock-induced organ injury in rats.

Insights on the mechanism of thioredoxin reductase inhibition by gold N-heterocyclic carbene compounds using the synthetic linear selenocysteine containing C-terminal peptide hTrxR(488-499): an ESI-MS investigation.

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Pratesi, Alessandro; Gabbiani, Chiara; Michelucci, Elena; Ginanneschi, Mauro; Papini, Anna Maria; Rubbiani, Riccardo; Ott, Ingo; Messori, Luigi

2014-07-01

Gold-based drugs typically behave as strong inhibitors of the enzyme thioredoxin reductase (hTrxR), possibly as the consequence of direct Gold(I) coordination to its active site selenocysteine. To gain a deeper insight into the molecular basis of enzyme inhibition and prove gold-selenocysteine coordination, the reactions of three parent Gold(I) NHC compounds with the synthetic C-terminal dodecapeptide of hTrxR containing Selenocysteine at position 498, were investigated by electrospray ionization mass spectrometry (ESI-MS). Formation of 1:1 Gold-peptide adducts, though in highly different amounts, was demonstrated in all cases. In these adducts the same [Au-NHC](+) moiety is always associated to the intact peptide. Afterward, tandem MS experiments, conducted on a specific Gold-peptide complex, pointed out that Gold is coordinated to the selenolate group. The relatively large strength of the Gold-selenolate coordinative bond well accounts for potent enzyme inhibition typically afforded by these Gold(I) compounds. In a selected case, the time course of enzyme inhibition was explored. Interestingly, enzyme inhibition turned out to show up very quickly and reached its maximum just few minutes after mixing. Overall, the present results offer some clear insight into the process of thioredoxin reductase inhibition by Gold-based compounds. Copyright © 2014 Elsevier Inc. All rights reserved.

Synthetic secoisolariciresinol diglucoside (LGM2605) inhibits myeloperoxidase activity in inflammatory cells.

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Mishra, Om P; Popov, Anatoliy V; Pietrofesa, Ralph A; Nakamaru-Ogiso, Eiko; Andrake, Mark; Christofidou-Solomidou, Melpo

2018-06-01

Myeloperoxidase (MPO) generates hypochlorous acid (HOCl) during inflammation and infection. We showed that secoisolariciresinol diglucoside (SDG) scavenges radiation-induced HOCl in physiological solutions. However, the action of SDG and its synthetic version, LGM2605, on MPO-catalyzed generation of HOCl is unknown. The present study evaluated the effect of LGM2605 on human MPO, and murine MPO from macrophages and neutrophils. MPO activity was determined fluorometrically using hypochlorite-specific 3'-(p-aminophenyl) fluorescein (APF). The effect of LGM2605 on (a) the peroxidase cycle of MPO was determined using Amplex Red while the effect on (b) the chlorination cycle was determined using a taurine chloramine assay. Using electron paramagnetic resonance (EPR) spectroscopy we determined the effect of LGM2605 on the EPR signals of MPO. Finally, computational docking of SDG was used to identify energetically favorable docking poses to enzyme's active site. LGM2605 inhibited human and murine MPO activity. MPO inhibition was observed in the absence and presence of Cl - . EPR confirmed that LGM2605 suppressed the formation of Compound I, an oxoiron (IV) intermediate [Fe(IV)O] containing a porphyrin π-radical of MPO's catalytic cycle. Computational docking revealed that SDG can act as an inhibitor by binding to the enzyme's active site. We conclude that LGM2605 inhibits MPO activity by suppressing both the peroxidase and chlorination cycles. EPR analysis demonstrated that LGM2605 inhibits MPO by decreasing the formation of the highly oxidative Compound I. This study identifies a novel mechanism of LGM2605 action as an inhibitor of MPO and indicates that LGM2605 may be a promising attenuator of oxidant-dependent inflammatory tissue damage. Copyright © 2018 Elsevier B.V. All rights reserved.

Extending breath analysis to the cellular level: current thoughts on the human microbiome and the expression of organic compounds in the human exposome

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Human biomarkers are comprised of compounds from cellular metabolism, oxidative stress, and the microbiome of bacteria in the gut, genitourinary, and pulmonary tracts. When we examine patterns in human biomarkers to discern human health state or diagnose specific diseases, it is...

Oxytetracycline Inhibits Mucus Secretion and Inflammation in Human Airway Epithelial Cells.

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Shah, Said Ahmad; Ishinaga, Hajime; Takeuchi, Kazuhiko

2017-01-01

Oxytetracycline is a broad-spectrum antibiotic, but its nonantibacterial effects in the human respiratory tract are unknown. In this study, the effects of oxytetracycline on mucus secretion and inflammation were examined by PCR and ELISA in the human airway epithelial cell line NCI-H292. Oxytetracycline (10 μg/mL) significantly inhibited TNF-α-induced MUC5AC gene expression and MUC5AC protein levels in NCI-H292 cells. It also downregulated IL-8 and IL-1β gene expression and IL-1β protein levels. Our findings demonstrated that oxytetracycline suppressed mucus production and inflammation in human respiratory epithelial cells, providing further evidence for the usefulness of oxytetracycline for human airway inflammatory diseases. © 2017 S. Karger AG, Basel.

Identification and characterization of haemofungin, a novel antifungal compound that inhibits the final step of haem biosynthesis.

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Ben Yaakov, Dafna; Rivkin, Anna; Mircus, Gabriel; Albert, Nathaniel; Dietl, Anna-Maria; Kovalerchick, Dimitry; Carmeli, Shmuel; Haas, Hubertus; Kontoyiannis, Dimitrios P; Osherov, Nir

2016-04-01

During recent decades, the number of invasive fungal infections among immunosuppressed patients has increased significantly, whereas the number of effective systemic antifungal drugs remains low and unsatisfactory. The aim of this study was to characterize a novel antifungal compound, CW-8/haemofungin, which we previously identified in a screen for compounds affecting fungal cell wall integrity. The in vitro characteristics of haemofungin were investigated by MIC evaluation against a panel of pathogenic and non-pathogenic fungi, bacteria and mammalian cells in culture. Haemofungin mode-of-action studies were performed by screening an Aspergillus nidulans overexpression genomic library for resistance-conferring plasmids and biochemical validation of the target. In vivo efficacy was tested in the Galleria mellonella and Drosophila melanogaster insect models of infection. We demonstrate that haemofungin causes swelling and lysis of growing fungal cells. It inhibits the growth of pathogenic Aspergillus, Candida, Fusarium and Rhizopus isolates at micromolar concentrations, while only weakly affecting the growth of mammalian cell lines. Genetic and biochemical analyses in A. nidulans and Aspergillus fumigatus indicate that haemofungin primarily inhibits ferrochelatase (HemH), the last enzyme in the haem biosynthetic pathway. Haemofungin was non-toxic and significantly reduced mortality rates of G. mellonella and D. melanogaster infected with A. fumigatus and Rhizopus oryzae, respectively. Further development and in vivo validation of haemofungin is warranted. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Rapamycin causes growth arrest and inhibition of invasion in human chondrosarcoma cells.

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Song, Jian; Wang, Xiaobo; Zhu, Jiaxue; Liu, Jun

2016-01-01

Chondrosarcoma is a highly malignant tumor that is characterized by a potent capacity to invade locally and cause distant metastasis and notable for its lack of response to conventional chemotherapy or radiotherapy. Rapamycin, the inhibitor of mammalian target of rapamycin (mTOR), is a valuable drug with diverse clinical applications and regulates many cellular processes. However, the effects of rapamycin on cell growth and invasion of human chondrosarcoma cells are not well known. We determined the effect of rapamycin on cell proliferation, cell cycle arrest and invasion by using MTS, flow cytometry and invasion assays in two human chondrosarcoma cell lines, SW1353 and JJ012. Cell cycle regulatory and invasion-related genes' expression analysis was performed by quantitative RT-PCR (qRT-PCR). We also evaluated the effect of rapamycin on tumor growth by using mice xenograph models. Rapamycin significantly inhibited the cell proliferation, induced cell cycle arrest and decreased the invasion ability of human chondrosarcoma cells. Meanwhile, rapamycin modulated the cell cycle regulatory and invasion-related genes' expression. Furthermore, the tumor growth of mice xenograph models with human chondrosarcoma cells was significantly inhibited by rapamycin. These results provided further insight into the role of rapamycin in chondrosarcoma. Therefore, rapamycin targeted therapy may be a potential treatment strategy for chondrosarcoma.

Morphological modulation of human fibrosarcoma HT-1080 cells by hydroxybenzoate compounds during apoptosis

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Jassem G Mahdi

2015-10-01

Full Text Available Hydroxybenzoate (HB compounds have shown to modulate the morphology in human fibrosarcoma HT-1080 cells. The changes in HT-1080 cells showed marker signs of apoptosis, which included the condensation of nucleus, cell round, blebbing and the formation of apoptotic bodies. The different stages of apoptosis were assessed microscopically using different staining and immunohistochemical techniques, as well as scanning electron microscopy. In addition, HB compounds increased the expression of caspase-3, which is closely associated with the development of the modulation in HT-1080 cells that are undergoing the programmed cell death. Both acetyl salicylic acid (ASA and HBZn compounds were dose and treatment duration dependent.

Effect of γ-lactones and γ-lactams compounds on Streptococcus mutans biofilms

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Mariane Beatriz Sordi

2018-02-01

Full Text Available Abstract Considering oral diseases, antibiofilm compounds can decrease the accumulation of pathogenic species such as Streptococcus mutans at micro-areas of teeth, dental restorations or implant-supported prostheses. Objective To assess the effect of thirteen different novel lactam-based compounds on the inhibition of S. mutans biofilm formation. Material and methods We synthesized compounds based on γ-lactones analogues from rubrolides by a mucochloric acid process and converted them into their corresponding γ-hydroxy-γ-lactams by a reaction with isobutylamine and propylamine. Compounds concentrations ranging from 0.17 up to 87.5 μg mL-1 were tested against S. mutans. We diluted the exponential cultures in TSB and incubated them (37°C in the presence of different γ-lactones or γ-lactams dilutions. Afterwards, we measured the planktonic growth by optical density at 630 nm and therefore assessed the biofilm density by the crystal violet staining method. Results Twelve compounds were active against biofilm formation, showing no effect on bacterial viability. Only one compound was inactive against both planktonic and biofilm growth. The highest biofilm inhibition (inhibition rate above 60% was obtained for two compounds while three other compounds revealed an inhibition rate above 40%. Conclusions Twelve of the thirteen compounds revealed effective inhibition of S. mutans biofilm formation, with eight of them showing a specific antibiofilm effect.

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

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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.

Fatty acid synthase inhibition triggers apoptosis during S phase in human cancer cells.

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Zhou, Weibo; Simpson, P Jeanette; McFadden, Jill M; Townsend, Craig A; Medghalchi, Susan M; Vadlamudi, Aravinda; Pinn, Michael L; Ronnett, Gabriele V; Kuhajda, Francis P

2003-11-01

C75, an inhibitor of fatty acid synthase (FAS), induces apoptosis in cultured human cancer cells. Its proposed mechanism of action linked high levels of malonyl-CoA after FAS inhibition to potential downstream effects including inhibition of carnitine palmitoyltransferase-1 (CPT-1) with resultant inhibition of fatty acid oxidation. Recent data has shown that C75 directly stimulates CPT-1 increasing fatty acid oxidation in MCF-7 human breast cancer cells despite inhibitory concentrations of malonyl-CoA. In light of these findings, we have studied fatty acid metabolism in MCF7 human breast cancer cells to elucidate the mechanism of action of C75. We now report that: (a) in the setting of increased fatty acid oxidation, C75 inhibits fatty acid synthesis; (b) C273, a reduced form of C75, is unable to inhibit fatty acid synthesis and is nontoxic to MCF7 cells; (c) C75 and 5-(tetradecyloxy)-2-furoic acid (TOFA), an inhibitor of acetyl-CoA carboxylase, both cause a significant reduction of fatty acid incorporation into phosphatidylcholine, the major membrane phospholipid, within 2 h; (d) pulse chase studies with [(14)C]acetate labeling of membrane lipids show that both C75 and TOFA accelerate the decay of (14)C-labeled lipid from membranes within 2 h; (e) C75 also promotes a 2-3-fold increase in oxidation of membrane lipids within 2 h; and (f) because interference with phospholipid synthesis during S phase is known to trigger apoptosis in cycling cells, we performed double-labeled terminal deoxynucleotidyltransferase-mediated nick end labeling and BrdUrd analysis with both TOFA and C75. C75 triggered apoptosis during S phase, whereas TOFA did not. Moreover, application of TOFA 2 h before C75 blocked the C75 induced apoptosis, whereas etomoxir did not. Taken together these data indicate that FAS inhibition and its downstream inhibition of phospholipid production is a necessary part of the mechanism of action of C75. CPT-1 stimulation does not likely play a role in the

Aliphatic alcohols in spirits inhibit phagocytosis by human monocytes.

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Pál, László; Árnyas, Ervin M; Bujdosó, Orsolya; Baranyi, Gergő; Rácz, Gábor; Ádány, Róza; McKee, Martin; Szűcs, Sándor

2015-04-01

A large volume of alcoholic beverages containing aliphatic alcohols is consumed worldwide. Previous studies have confirmed the presence of ethanol-induced immunosuppression in heavy drinkers, thereby increasing susceptibility to infectious diseases. However, the aliphatic alcohols contained in alcoholic beverages might also impair immune cell function, thereby contributing to a further decrease in microbicidal activity. Previous research has shown that aliphatic alcohols inhibit phagocytosis by granulocytes but their effect on human monocytes has not been studied. This is important as they play a crucial role in engulfment and killing of pathogenic microorganisms and a decrease in their phagocytic activity could lead to impaired antimicrobial defence in heavy drinkers. The aim of this study was to measure monocyte phagocytosis following their treatment with those aliphatic alcohols detected in alcoholic beverages. Monocytes were separated from human peripheral blood and phagocytosis of opsonized zymosan particles by monocytes treated with ethanol and aliphatic alcohols individually and in combination was determined. It was shown that these alcohols could suppress the phagocytic activity of monocytes in a concentration-dependent manner and when combined with ethanol, they caused a further decrease in phagocytosis. Due to their additive effects, it is possible that they may inhibit phagocytosis in a clinically meaningful way in alcoholics and episodic heavy drinkers thereby contribute to their increased susceptibility to infectious diseases. However, further research is needed to address this question.

Tyrphostin AG-related compounds attenuate H2O2-induced TRPM2-dependent and -independent cellular responses.

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Yamamoto, Shinichiro; Toda, Takahiro; Yonezawa, Ryo; Negoro, Takaharu; Shimizu, Shunichi

2017-05-01

TRPM2 is a Ca 2+ -permeable channel that is activated by H 2 O 2 . TRPM2-mediated Ca 2+ signaling has been implicated in the aggravation of inflammatory diseases. Therefore, the development of TRPM2 inhibitors to prevent the aggravation of these diseases is expected. We recently reported that some Tyrphostin AG-related compounds inhibited the H 2 O 2 -induced activation of TRPM2 by scavenging the intracellular hydroxyl radical. In the present study, we examined the effects of AG-related compounds on H 2 O 2 -induced cellular responses in human monocytic U937 cells, which functionally express TRPM2. The effects of AG-related compounds on H 2 O 2 -induced changes in intracellular Ca 2+ concentrations, extracellular signal-regulated kinase (ERK) activation, and CXCL8 secretion were assessed using U937 cells. Ca 2+ influxes via TRPM2 in response to H 2 O 2 were blocked by AG-related compounds. AG-related compounds also inhibited the H 2 O 2 -induced activation of ERK, and subsequent secretion of CXCL8 mediated by TRPM2-dependent and -independent mechanisms. Our results show that AG-related compounds inhibit H 2 O 2 -induced CXCL8 secretion following ERK activation, which is mediated by TRPM2-dependent and -independent mechanisms in U937 cells. We previously reported that AG-related compounds blocked H 2 O 2 -induced TRPM2 activation by scavenging the hydroxyl radical. The inhibitory effects of AG-related compounds on TRPM2-independent responses may be due to scavenging of the hydroxyl radical. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Probenecid inhibits α-adrenergic receptor-mediated vasoconstriction in the human leg vasculature

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Nyberg, Michael Permin; Piil, Peter Bergmann; Kiehn, Oliver Thistrup

2018-01-01

to α1- and α2-adrenergic receptor stimulation in the human forearm and leg vasculature of young healthy male subjects (23±3 years). By use of immunolabeling and confocal microscopy, Panx1 channels were found to be expressed in vascular smooth muscle cells of arterioles in human leg skeletal muscle....... Probenecid treatment increased (Padrenergic receptor stimulation) by ≈15%, whereas the response to the α1-agonist phenylephrine was unchanged. Inhibition...

Opposite responses of rabbit and human globin mRNAs to translational inhibition by cap analogues

International Nuclear Information System (INIS)

Shakin, S.H.; Liebhaber, S.A.

1987-01-01

The translational efficiency of an mRNA may be determined at the step of translational initiation by the efficiency of its interaction with the cap binding protein complex. To further investigate the role of these interactions in translational control, the authors compare in vitro the relative sensitivities of rabbit and human α- and β-globin mRNAs to translational inhibition by cap analogues. They find that rabbit β-globin mRNA is more resistant to translational inhibition by cap analogues than rabbit α-globin mRNA, while in contrast, human β-globin mRNA is more sensitive to cap analogue inhibition than human α- and β-globin mRNAs is unexpected as direct in vivo and in vitro comparisons of polysome profiles reveal parallel translational handling of the α- and β-globin mRNAs from these two species. This discordance between the relative translational sensitivities of these mRNAs to cap analogues and their relative ribosome loading activities suggests that cap-dependent events may not be rate limiting in steady-state globin translation

Caffeoyl glucosides from Nandina domestica inhibit LPS-induced endothelial inflammatory responses.

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Kulkarni, Roshan R; Lee, Wonhwa; Jang, Tae Su; Lee, JungIn; Kwak, Soyoung; Park, Mi Seon; Lee, Hyun-Shik; Bae, Jong-Sup; Na, MinKyun

2015-11-15

Endothelial dysfunction is a key pathological feature of many inflammatory diseases, including sepsis. In the present study, a new caffeoyl glucoside (1) and two known caffeoylated compounds (2 and 3) were isolated from the fruits of Nandina domestica Thunb. (Berberidaceae). The compounds were investigated for their effects against lipopolysaccharide (LPS)-mediated endothelial inflammatory responses. At 20 μM, 1 and 2 inhibited LPS-induced hyperpermeability, adhesion, and migration of leukocytes across a human endothelial cell monolayer in a dose-dependent manner suggesting that 1 and 2 may serve as potential scaffolds for the development of therapeutic agents to treat vascular inflammatory disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

Morus alba and active compound oxyresveratrol exert anti-inflammatory activity via inhibition of leukocyte migration involving MEK/ERK signaling.

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Chen, Yi-Ching; Tien, Yin-Jing; Chen, Chun-Houh; Beltran, Francesca N; Amor, Evangeline C; Wang, Ran-Juh; Wu, Den-Jen; Mettling, Clément; Lin, Yea-Lih; Yang, Wen-Chin

2013-02-23

Morus alba has long been used in traditional Chinese medicine to treat inflammatory diseases; however, the scientific basis for such usage and the mechanism of action are not well understood. This study investigated the action of M. alba on leukocyte migration, one key step in inflammation. Gas chromatography-mass spectrometry (GC-MS) and cluster analyses of supercritical CO2 extracts of three Morus species were performed for chemotaxonomy-aided plant authentication. Phytochemistry and CXCR4-mediated chemotaxis assays were used to characterize the chemical and biological properties of M. alba and its active compound, oxyresveratrol. fluorescence-activated cell sorting (FACS) and Western blot analyses were conducted to determine the mode of action of oxyresveratrol. Chemotaxonomy was used to help authenticate M. alba. Chemotaxis-based isolation identified oxyresveratrol as an active component in M. alba. Phytochemical and chemotaxis assays showed that the crude extract, ethyl acetate fraction and oxyresveratrol from M. alba suppressed cell migration of Jurkat T cells in response to SDF-1. Mechanistic study indicated that oxyresveratrol diminished CXCR4-mediated T-cell migration via inhibition of the MEK/ERK signaling cascade. A combination of GC-MS and cluster analysis techniques are applicable for authentication of the Morus species. Anti-inflammatory benefits of M. alba and its active compound, oxyresveratrol, may involve the inhibition of CXCR-4-mediated chemotaxis and MEK/ERK pathway in T and other immune cells.

Magnolol Inhibits the Growth of Non-Small Cell Lung Cancer via Inhibiting Microtubule Polymerization

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Jia Shen

2017-07-01

Full Text Available Background: The tubulin/microtubule system, which is an integral component of the cytoskeleton, plays an essential role in mitosis. Targeting mitotic progression by disturbing microtubule dynamics is a rational strategy for cancer treatment. Methods: Microtubule polymerization assay was performed to examine the effect of Magnolol (a novel natural phenolic compound isolated from Magnolia obovata on cellular microtubule polymerization in human non-small cell lung cancer (NSCLC cells. Cell cycle analysis, mitotic index assay, cell proliferation assay, colony formation assay, western blotting analysis of cell cycle regulators, Annexin V-FITC/PI staining, and live/dead viability staining were carried out to investigate the Magnolol’s inhibitory effect on proliferation and viability of NSCLS cells in vitro. Xenograft model of human A549 NSCLC tumor was used to determine the Magnolol’s efficacy in vivo. Results: Magnolol treatment effectively inhibited cell proliferation and colony formation of NSCLC cells. Further study proved that Magnolol induced the mitotic phase arrest and inhibited G2/M progression in a dose-dependent manner, which were mechanistically associated with expression alteration of a series of cell cycle regulators. Furthermore, Magnolol treatment disrupted the cellular microtubule organization via inhibiting the polymerization of microtubule. We also found treatment with NSCLC cells with Magnolol resulted in apoptosis activation through a p53-independent pathway, and autophgy induction via down-regulation of the Akt/mTOR pathway. Finally, Magnolol treatment significantly suppressed the NSCLC tumor growth in mouse xenograft model in vivo. Conclusion: These findings identify Magnolol as a promising candidate with anti-microtubule polymerization activity for NSCLC treatment.

Discovery of nonsteroidal 17beta-hydroxysteroid dehydrogenase 1 inhibitors by pharmacophore-based screening of virtual compound libraries.

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Schuster, Daniela; Nashev, Lyubomir G; Kirchmair, Johannes; Laggner, Christian; Wolber, Gerhard; Langer, Thierry; Odermatt, Alex

2008-07-24

17Beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD1) plays a pivotal role in the local synthesis of the most potent estrogen estradiol. Its expression is a prognostic marker for the outcome of patients with breast cancer and inhibition of 17beta-HSD1 is currently under consideration for breast cancer prevention and treatment. We aimed to identify nonsteroidal 17beta-HSD1 inhibitor scaffolds by virtual screening with pharmacophore models built from crystal structures containing steroidal compounds. The most promising model was validated by comparing predicted and experimentally determined inhibitory activities of several flavonoids. Subsequently, a virtual library of nonsteroidal compounds was screened against the 3D pharmacophore. Analysis of 14 selected compounds yielded four that inhibited the activity of human 17beta-HSD1 (IC 50 below 50 microM). Specificity assessment of identified 17beta-HSD1 inhibitors emphasized the importance of including related short-chain dehydrogenase/reductase (SDR) members to analyze off-target effects. Compound 29 displayed at least 10-fold selectivity over the related SDR enzymes tested.

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

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

2015-10-01

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 (40mg/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. Copyright © 2015 Elsevier Inc. All rights reserved.

Strawberry Achenes Are an Important Source of Bioactive Compounds for Human Health

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María Teresa Ariza

2016-07-01

Full Text Available Strawberries are highly appreciated for their taste, nutritional value and antioxidant compounds, mainly phenolics. Fruit antioxidants derive from achenes and flesh, but achene contribution to the total fruit antioxidant capacity and to the bioaccessibility after intake is still unknown. In this work, the content of total phenolic compounds, flavonoids, anthocyanins and antioxidant capacity (TEAC, FRAP and DPPH of achenes and flesh were compared in non-digested as well as in gastric and intestinal extracts after in vitro digestion. Results showed that, despite strawberry achenes represent a small fraction of the fruit, their contribution to total fruit antioxidant content was more than 41% and accounted for 81% of antioxidant capacity (TEAC. Achenes have higher quantity and different quality of antioxidants in non-digested and digested extracts. Antioxidant release was higher in the in vitro gastric digested extracts, but digestion conditions did not only affect quantity but quality, resulting in differences in antioxidant capacity and highlighting the importance of simulating physiological-like extraction conditions for assessing fruit antioxidant properties on human health. These results give new insights into the use of strawberry achenes as a source of bioactive compounds to be considered in strawberry breeding programs for improving human health.

Strawberry Achenes Are an Important Source of Bioactive Compounds for Human Health

Science.gov (United States)

Ariza, María Teresa; Reboredo-Rodríguez, Patricia; Mazzoni, Luca; Forbes-Hernández, Tamara Yuliett; Giampieri, Francesca; Afrin, Sadia; Gasparrini, Massimiliano; Soria, Carmen; Martínez-Ferri, Elsa; Battino, Maurizio; Mezzetti, Bruno

2016-01-01

Strawberries are highly appreciated for their taste, nutritional value and antioxidant compounds, mainly phenolics. Fruit antioxidants derive from achenes and flesh, but achene contribution to the total fruit antioxidant capacity and to the bioaccessibility after intake is still unknown. In this work, the content of total phenolic compounds, flavonoids, anthocyanins and antioxidant capacity (TEAC, FRAP and DPPH) of achenes and flesh were compared in non-digested as well as in gastric and intestinal extracts after in vitro digestion. Results showed that, despite strawberry achenes represent a small fraction of the fruit, their contribution to total fruit antioxidant content was more than 41% and accounted for 81% of antioxidant capacity (TEAC). Achenes have higher quantity and different quality of antioxidants in non-digested and digested extracts. Antioxidant release was higher in the in vitro gastric digested extracts, but digestion conditions did not only affect quantity but quality, resulting in differences in antioxidant capacity and highlighting the importance of simulating physiological-like extraction conditions for assessing fruit antioxidant properties on human health. These results give new insights into the use of strawberry achenes as a source of bioactive compounds to be considered in strawberry breeding programs for improving human health. PMID:27409612

Edaravone Protected Human Brain Microvascular Endothelial Cells from Methylglyoxal-Induced Injury by Inhibiting AGEs/RAGE/Oxidative Stress

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Li, Wenlu; Xu, Hongjiao; Hu, Yangmin; He, Ping; Ni, Zhenzhen; Xu, Huimin; Zhang, Zhongmiao; Dai, Haibin

2013-01-01

Subjects with diabetes experience an increased risk of cerebrovascular disease and stroke compared with nondiabetic age-matched individuals. Increased formation of reactive physiological dicarbonyl compound methylglyoxal (MGO) seems to be implicated in the development of diabetic vascular complication due to its protein glycation and oxidative stress effect. Edaravone, a novel radical scavenger, has been reported to display the advantageous effects on ischemic stroke both in animals and clinical trials; however, little is known about whether edaravone has protective effects on diabetic cerebrovascular injury. Using cultured human brain microvascular endothelial cells (HBMEC), protective effects of edaravone on MGO and MGO enhancing oxygen-glucose deprivation (OGD) induced injury were investigated. Cell injury was measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) formation, cell account, lactate dehydrogenase (LDH) release and Rhodamine 123 staining. Advanced glycation end-products (AGEs) formation and receptor for advanced glycation end-products (RAGE) expression were measured by western blotting. Cellular oxidative stress was measured by reactive oxygen species (ROS) release. Treatment of MGO for 24 h significantly induced HBMEC injury, which was inhibited by pretreatment of edaravone from 10–100 µmol/l. What’s more, treatment of MGO enhanced AGEs accumulation, RAGE expression and ROS release in the cultured HBMEC, which were inhibited by 100 µmol/l edaravone. Finally, treatment of MGO for 24 h and then followed by 3 h OGD insult significantly enhanced cell injury when compared with OGD insult only, which was also protected by 100 µmol/l edaravone. Thus, edaravone protected HBMEC from MGO and MGO enhancing OGD-induced injury by inhibiting AGEs/RAGE/oxidative stress. PMID:24098758

Edaravone protected human brain microvascular endothelial cells from methylglyoxal-induced injury by inhibiting AGEs/RAGE/oxidative stress.

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Wenlu Li

Full Text Available Subjects with diabetes experience an increased risk of cerebrovascular disease and stroke compared with nondiabetic age-matched individuals. Increased formation of reactive physiological dicarbonyl compound methylglyoxal (MGO seems to be implicated in the development of diabetic vascular complication due to its protein glycation and oxidative stress effect. Edaravone, a novel radical scavenger, has been reported to display the advantageous effects on ischemic stroke both in animals and clinical trials; however, little is known about whether edaravone has protective effects on diabetic cerebrovascular injury. Using cultured human brain microvascular endothelial cells (HBMEC, protective effects of edaravone on MGO and MGO enhancing oxygen-glucose deprivation (OGD induced injury were investigated. Cell injury was measured by 3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT formation, cell account, lactate dehydrogenase (LDH release and Rhodamine 123 staining. Advanced glycation end-products (AGEs formation and receptor for advanced glycation end-products (RAGE expression were measured by western blotting. Cellular oxidative stress was measured by reactive oxygen species (ROS release. Treatment of MGO for 24 h significantly induced HBMEC injury, which was inhibited by pretreatment of edaravone from 10-100 µmol/l. What's more, treatment of MGO enhanced AGEs accumulation, RAGE expression and ROS release in the cultured HBMEC, which were inhibited by 100 µmol/l edaravone. Finally, treatment of MGO for 24 h and then followed by 3 h OGD insult significantly enhanced cell injury when compared with OGD insult only, which was also protected by 100 µmol/l edaravone. Thus, edaravone protected HBMEC from MGO and MGO enhancing OGD-induced injury by inhibiting AGEs/RAGE/oxidative stress.

Flavonoids as Inhibitors of Human Butyrylcholinesterase Variants

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Maja Katalinić

2014-01-01

Full Text Available The inhibition of butyrylcholinesterase (BChE, EC 3.1.1.8 appears to be of interest in treating diseases with symptoms of reduced neurotransmitter levels, such as Alzheimer’s disease. However, BCHE gene polymorphism should not be neglected in research since it could have an effect on the expected outcome. Several well-known cholinergic drugs (e.g. galantamine, huperzine and rivastigmine originating from plants, or synthesised as derivatives of plant compounds, have shown that herbs could serve as a source of novel target-directed compounds. We focused our research on flavonoids, biologically active polyphenolic compounds found in many plants and plant-derived products, as BChE inhibitors. All of the tested flavonoids: galangin, quercetin, fisetin and luteolin reversibly inhibited usual, atypical, and fluoride-resistant variants of human BChE. The inhibition potency increased in the following order, identically for all three BChE variants: luteolininhibition potency of selected flavonoids exists in view of BChE polymorphism. Our results suggested that flavonoids could assist the further development of new BChE-targeted drugs for treating symptoms of neurodegenerative diseases and dementia.

Human carbonyl reductase 1 participating in intestinal first-pass drug metabolism is inhibited by fatty acids and acyl-CoAs.

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Hara, Akira; Endo, Satoshi; Matsunaga, Toshiyuki; El-Kabbani, Ossama; Miura, Takeshi; Nishinaka, Toru; Terada, Tomoyuki

2017-08-15

Human carbonyl reductase 1 (CBR1), a member of the short-chain dehydrogenase/reductase (SDR) superfamily, reduces a variety of carbonyl compounds including endogenous isatin, prostaglandin E 2 and 4-oxo-2-nonenal. It is also a major non-cytochrome P450 enzyme in the phase I metabolism of carbonyl-containing drugs, and is highly expressed in the intestine. In this study, we found that long-chain fatty acids and their CoA ester derivatives inhibit CBR1. Among saturated fatty acids, myristic, palmitic and stearic acids were inhibitory, and stearic acid was the most potent (IC 50 9µM). Unsaturated fatty acids (oleic, elaidic, γ-linolenic and docosahexaenoic acids) and acyl-CoAs (palmitoyl-, stearoyl- and oleoyl-CoAs) were more potent inhibitors (IC 50 1.0-2.5µM), and showed high inhibitory selectivity to CBR1 over its isozyme CBR3 and other SDR superfamily enzymes (DCXR and DHRS4) with CBR activity. The inhibition by these fatty acids and acyl-CoAs was competitive with respect to the substrate, showing the K i values of 0.49-1.2µM. Site-directed mutagenesis of the substrate-binding residues of CBR1 suggested that the interactions between the fatty acyl chain and the enzyme's Met141 and Trp229 are important for the inhibitory selectivity. We also examined CBR1 inhibition by oleic acid in cellular levels: The fatty acid effectively inhibited CBR1-mediated 4-oxo-2-nonenal metabolism in colon cancer DLD1 cells and increased sensitivity to doxorubicin in the drug-resistant gastric cancer MKN45 cells that highly express CBR1. The results suggest a possible new food-drug interaction through inhibition of CBR1-mediated intestinal first-pass drug metabolism by dietary fatty acids. Copyright © 2017 Elsevier Inc. All rights reserved.

Metabolic interactions between acetaminophen (paracetamol) and two flavonoids, luteolin and quercetin, through in-vitro inhibition studies.

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Cao, Lei; Kwara, Awewura; Greenblatt, David J

2017-12-01

Excessive exposure to acetaminophen (APAP, paracetamol) can cause liver injury through formation of a reactive metabolite that depletes hepatic glutathione and causes hepatocellular oxidative stress and damage. Generation of this metabolite is mediated by Cytochrome-P450 (CYP) isoforms, mainly CYP2E1. A number of naturally occurring flavonoids can mitigate APAP-induced hepatotoxicity in experimental animal models. Our objective was to determine the mechanism of these protective effects and to evaluate possible human applicability. Two flavonoids, luteolin and quercetin, were evaluated as potential inhibitors of eight human CYP isoforms, of six UDP-glucuronosyltransferase (UGT) isoforms and of APAP glucuronidation and sulfation. The experimental model was based on in-vitro metabolism by human liver microsomes, using isoform-specific substrates. Luteolin and quercetin inhibited human CYP isoforms to varying degrees, with greatest potency towards CYP1A2 and CYP2C8. However, 50% inhibitory concentrations (IC 50 values) were generally in the micromolar range. UGT isoforms were minimally inhibited. Both luteolin and quercetin inhibited APAP sulfation but not glucuronidation. Inhibition of human CYP activity by luteolin and quercetin occurred with IC 50 values exceeding customary in-vivo human exposure with tolerable supplemental doses of these compounds. The findings indicate that luteolin and quercetin are not likely to be of clinical value for preventing or treating APAP-induced hepatotoxicity. © 2017 Royal Pharmaceutical Society.

Naloxone inhibits superoxide but not enzyme release by human neutrophils

International Nuclear Information System (INIS)

Simpkins, C.; Alailima, S.; Tate, E.

1986-01-01

The release of toxic oxygen metabolites and enzymes by phagocytic cells is thought to play a role in the multisystemic tissue injury of sepsis. Naloxone protects septic animals. We have found that at concentrations administered to animals (10 -7 to 10 -4 M), naloxone inhibited (p 2 - ) by human neutrophils (HN), stimulated with N-formyl methionyl leucyl phenylalanine (FMLP). Naloxone had no effect on cell viability. Maximum inhibition was 65% of the total O 2 - released (13.1 nMoles/8 min/320,000 cells). FMLP-stimulated release of beta-glucoronidase or lysozyme was not altered by naloxone. Naloxone had no effect on the binding of 3 H FMLP to HN. Using 3 H naloxone and various concentrations of unlabeled naloxone higher affinity (K/sub D/ = 12nM) and lower affinity (K/sub D/ = 4.7 x 10 -5 ) binding sites were detected. The K/sub D/ of the low affinity site corresponded to the ED 50 for naloxone inhibition of O 2 - (1 x 10 -5 M). Binding to this low affinity site was decreased by (+) naloxone, beta-endorphin and N acetyl beta-endorphin, but not by leu-enkephalin, thyrotropin releasing factor, prostaglandin D 2 or E 2 . Conclusions: (1) naloxone inhibits FMLP-stimulated O 2 but not enzyme release, (2) this inhibition is not due to alteration of FMLP receptor binding, (3) naloxone may act via a low affinity binding site which is ligand specific, and (4) a higher affinity receptor is present on HN

Modulation of recurrent inhibition from knee extensors to ankle motoneurones during human walking

DEFF Research Database (Denmark)

Lamy, Jean-Charles; Iglesias, Caroline; Lackmy, Alexandra

2008-01-01

The neural control for muscle coordination during human locomotion involves spinal and supraspinal networks, but little is known about the exact mechanisms implicated. The present study focused on modulation of heteronymous recurrent inhibition from knee extensors to ankle motoneurones at different...... times in the gait cycle, when quadriceps (Quad) muscle activity overlaps that in tibialis anterior (TA) and soleus (Sol). The effects of femoral nerve stimulation on ankle motoneurones were investigated during treadmill walking and during tonic co-contraction of Quad and TA/Sol while standing. Recurrent...... inhibition of TA motoneurones depended on the level of background EMG, and was similar during walking and standing for matched background EMG levels. On the other hand, recurrent inhibition in Sol was reduced in early stance, with respect to standing, and enhanced in late stance. Reduced inhibition in Sol...

Cyclooxygenase inhibition improves endothelial vasomotor dysfunction of visceral adipose arterioles in human obesity

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Farb, Melissa G.; Tiwari, Stephanie; Karki, Shakun; Ngo, Doan TM; Carmine, Brian; Hess, Donald T.; Zuriaga, Maria A.; Walsh, Kenneth; Fetterman, Jessica L.; Hamburg, Naomi M.; Vita, Joseph A.; Apovian, Caroline M.; Gokce, Noyan

2013-01-01

Objective The purpose of this study was to determine whether cyclooxygenase inhibition improves vascular dysfunction of adipose microvessels from obese humans. Design and Methods In 20 obese subjects (age 37±12 yrs, BMI 47±8 kg/m2) we collected subcutaneous and visceral fat during bariatric surgery and characterized adipose depot-specific gene expression, endothelial cell phenotype, and microvascular function. Vasomotor function was assessed in response to endothelium-dependent agonists using videomicroscopy of small arterioles from fat. Results Arterioles from visceral fat exhibited impaired endothelium-dependent, acetylcholine-mediated vasodilation, compared to the subcutaneous depot (p<0.001). Expression of mRNA transcripts relevant to the cyclooxygenase pathway were upregulated in visceral compared to subcutaneous fat. Pharmacological inhibition of cyclooxygenase with indomethacin improved endothelium-dependent vasodilator function of arterioles from visceral fat by 2-fold (p=0.01), whereas indomethacin had no effect in the subcutaneous depot. Indomethacin increased activation via serine-1177 phosphorylation of endothelial nitric oxide synthase in response to acetylcholine in endothelial cells from visceral fat. Inhibition of endothelial nitric oxide synthase with Nω-nitro-L-arginine methyl ester abrogated the effects of cyclooxygenase-inhibition suggesting that vascular actions of indomethacin were related to increased nitric oxide bioavailability. Conclusions Our findings suggest that cyclooxygenase-mediated vasoconstrictor prostanoids partly contribute to endothelial dysfunction of visceral adipose arterioles in human obesity. PMID:23640904

Diterpenoids from Tetraclinis articulata that inhibit various human leukocyte functions.

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Barrero, Alejandro F; Quílez del Moral, José F; Lucas, Rut; Payá, Miguel; Akssira, Mohamed; Akaad, Said; Mellouki, Fouad

2003-06-01

Ten new compounds, eight of them pimarane derivatives (1-8), together with a menthane dimer (9) and a totarane diterpenoid (10), were isolated from the leaves and wood of Tetraclinis articulata. The structures of 1-10 were established by using spectroscopic techniques, including 2D NMR spectra. Pimaranes 1-5 were found to possess an unusual cis interannular union of the B and C rings, which, from a biogenetic perspective, could be derived from the hydration of a carbocation at C-8. Compounds 4-6 and a mixture of 7 and 11 modulated different human leukocyte functions at a concentration of 10 microM, mainly the degranulation process measured as myeloperoxidase release and, to a lesser extent, the superoxide production measured by chemiluminescence.

The pharmacological profile of CGP 28238, a novel highly potent anti-inflammatory compound.

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Wiesenberg-Boettcher, I; Schweizer, A; Green, J R; Mueller, K; Maerki, F; Pfeilschifter, J

1989-01-01

CGP 28238 (6-(2,4-difluorophenoxy)-5-methylsulfonylamino-1-indanone ) exhibits very potent anti-inflammatory activity in rat adjuvant arthritis (ED40 = 0.05 mg/kg, p.o.) and pronounced analgesic and antipyretic activity in acute models in mice and rats (ED50 2-5 mg/kg, p.o.), but has clear advantages over reference NSAIDs with respect to gastro-intestinal tolerability. Threshold doses for gastro-intestinal ulcerogenicity in rats after single and repeated (10x) doses were found to be 30 mg/kg, p.o., and prostaglandin (PGE2) production in rat gastric and ileal mucosa was only marginally inhibited (ED50 greater than 30 mg/kg, p.o.). On the other hand, PGE2 production in rat inflammatory exudate and thromboxane synthesis in rat blood were inhibited with ED50 values of less than or equal to 2 mg/kg, p.o. Although CGP28238 does not inhibit cyclooxygenase in bovine seminal vesicle microsomal preparations (IC50 greater than 10(-3) mol/l), potent inhibition of prostaglandin synthesis was shown in various in vitro systems using human and animal cells with IC50 values of less than 10(-6) mol/l. IL-1-stimulated bone resorption and PGE2 production in murine calvarial cultures were inhibited with IC50 values of 3 x 10(-7) and 2 x 10(-8) mol/l, respectively. 5-Lipoxygenase (murine macrophages), phospholipase A2 (human PMN) and phospholipase C (human platelets) were not inhibited. CGP 28238 may represent a novel highly potent anti-inflammatory compound with improved gastro-intestinal safety.

Novel Platinum (Pt)-Vandetanib Hybrid Compounds: Design, Synthesis and Investigation of Anti-cancer Activity and Mechanism of Action

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Fei, Rong

of them formed mono-dentate adducts. Moreover, hybrid compounds exhibited low toxicity in human normal kidney cells. Compounds maintained the inhibition selectivity towards EGFR from the results of kinase inhibition profiling and cell-free kinase inhibition assay. Hybrids formed strong H-bond at D800 on EGFR. Pt-vandetanib hybrids were highly effective against HCC827 cells harboring sensitizing EGFR mutation. Importantly, relative resistant rate of hybrids were much smaller than vandetanib in H1975 cells. Western blot analysis results revealed that the hybrid compounds could efficiently inhibit EGFR phosphorylation in a dose dependent manner in HCC827. While, inhibition of p-EGFR was not as good as the original TKI in H1975 cells. However, the hybrid compounds induced DNA damage and caused apoptosis of the NSCLC cells. Both of the two pathways were contributed to cancer cell death and overcome vandetanib resistance. Pt-vandetanib hybrids showed little resistance in cisplatin resistant cell line KB-CP20. Drug accumulation evaluation revealed that cisplatin accumulation in CP20 cells decreased to one eighth of that in the parental KB3.1 cells. While hybrids maintained similar drug accumulation extent in both cells lines. Mechanistic study showed that hybrid compounds could induce DNA damage and cause apoptosis, whereas cisplatin failed to cause DNA damage in KB-CP20 cells. Oncoprotein CIP2A was overexpressed in CP20 cell and was ascribed to CDDP resistance. The hybrids inhibited CIP2A expression and downstream AKT phosphorylation. It was hypothesized that downregulation of CIP2A contributed to circumvention platinum resistance. Conclusion: Novel Pt-vandetanib hybrid compounds were able to overcome vandetanib resistance in H1975 cells by maintaining inhibition to the EGFR and inducing DNA damage and apoptosis. Moreover, Pt-vandetanib hybrid compounds behaved low toxicity and overcome cisplatin resistance by being "non-substrate" to efflux transporter and successfully

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

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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.

Perfluorinated compounds in human serum and seminal plasma from an urban and rural population in Sri Lanka

Energy Technology Data Exchange (ETDEWEB)

Guruge, Keerthi; Miyazaki, Shigeru; Yamanaka, Noriko [National Institute of Animal Health, Tsukuba (Japan); Taniyasu, Sacgu; Yamashita, Nobuyoshi [National Institute of Advance Industrial and Technology, Tsukuba (Japan); Wijeratna, S.; Seneviratne, H. [Colombo Univ. (Sri Lanka)

2004-09-15

Fluorinated organic compounds (FOCs) have been used for variety of industrial applications such as surfactants, adhesives, insecticides, and their global production increase since 1970s. These compounds repel both water and oil. The high-energy carbon-fluorine covalent bonds in FOCs are strong enough to have high persistency in the environment. These compounds emerged as priory environmental pollutants since they are found in various biota throughout the world. Human contamination of some FOCs was reported mostly in developed countries such as USA, Japan and from Europe. In the present study, we report 10 FOCs in human serum including seminal plasma for the first time, collected from volunteers from Sri Lanka.

Human-Phosphate-Binding-Protein inhibits HIV-1 gene transcription and replication

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Candolfi Ermanno

2011-07-01

Full Text Available Abstract The Human Phosphate-Binding protein (HPBP is a serendipitously discovered lipoprotein that binds phosphate with high affinity. HPBP belongs to the DING protein family, involved in various biological processes like cell cycle regulation. We report that HPBP inhibits HIV-1 gene transcription and replication in T cell line, primary peripherical blood lymphocytes and primary macrophages. We show that HPBP is efficient in naïve and HIV-1 AZT-resistant strains. Our results revealed HPBP as a new and potent anti HIV molecule that inhibits transcription of the virus, which has not yet been targeted by HAART and therefore opens new strategies in the treatment of HIV infection.

Explaining Compound Generalization in Associative and Causal Learning Through Rational Principles of Dimensional Generalization

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Soto, Fabian A.; Gershman, Samuel J.; Niv, Yael

2014-01-01

How do we apply learning from one situation to a similar, but not identical, situation? The principles governing the extent to which animals and humans generalize what they have learned about certain stimuli to novel compounds containing those stimuli vary depending on a number of factors. Perhaps the best studied among these factors is the type of stimuli used to generate compounds. One prominent hypothesis is that different generalization principles apply depending on whether the stimuli in a compound are similar or dissimilar to each other. However, the results of many experiments cannot be explained by this hypothesis. Here we propose a rational Bayesian theory of compound generalization that uses the notion of consequential regions, first developed in the context of rational theories of multidimensional generalization, to explain the effects of stimulus factors on compound generalization. The model explains a large number of results from the compound generalization literature, including the influence of stimulus modality and spatial contiguity on the summation effect, the lack of influence of stimulus factors on summation with a recovered inhibitor, the effect of spatial position of stimuli on the blocking effect, the asymmetrical generalization decrement in overshadowing and external inhibition, and the conditions leading to a reliable external inhibition effect. By integrating rational theories of compound and dimensional generalization, our model provides the first comprehensive computational account of the effects of stimulus factors on compound generalization, including spatial and temporal contiguity between components, which have posed longstanding problems for rational theories of associative and causal learning. PMID:25090430

Licoricidin inhibits the growth of SW480 human colorectal adenocarcinoma cells in vitro and in vivo by inducing cycle arrest, apoptosis and autophagy

Energy Technology Data Exchange (ETDEWEB)

Ji, Shuai [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou 221004 (China); Tang, Shunan; Li, Kai; Li, Ziwei; Liang, Wenfei; Qiao, Xue; Wang, Qi [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Yu, Siwang, E-mail: swang_yu@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Ye, Min, E-mail: yemin@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China)

2017-07-01

Licorice (Glycyrrhiza uralensis Fisch.) possesses significant anti-cancer activities, but the active ingredients and underlying mechanisms have not been revealed. By screening the cytotoxic activities of 122 licorice compounds against SW480 human colorectal adenocarcinoma cells, we found that licoricidin (LCD) inhibited SW480 cell viability with an IC{sub 50} value of 7.2 μM. Further studies indicated that LCD significantly induced G1/S cell cycle arrest and apoptosis in SW480 cells, accompanied by inhibition of cyclins/CDK1 expression and activation of caspase-dependent pro-apoptotic signaling. Meanwhile, LCD promoted autophagy in SW480 cells, and activated AMPK signaling and inhibited Akt/mTOR pathway. Overexpression of a dominant-negative AMPKα2 abolished LCD-induced inhibition of Akt/mTOR, autophagic and pro-apoptotic signaling pathways, and significantly reversed loss of cell viability, suggesting activation of AMPK is essential for the anti-cancer activity of LCD. In vivo anti-tumor experiments indicated that LCD (20 mg/kg, i.p.) significantly inhibited the growth of SW480 xenografts in nude mice with an inhibitory rate of 43.5%. In addition, we obtained the glycosylated product LCDG by microbial transformation, and found that glycosylation slightly enhanced the in vivo anti-cancer activities of LCD. This study indicates that LCD could inhibit SW480 cells by inducing cycle arrest, apoptosis and autophagy, and is a potential chemopreventive or chemotherapeutic agent against colorectal cancer. - Highlights: • Molecular mechanisms for cytotoxic activity of licoricidin (LCD) were investigated. • LCD promoted autophagy of SW480 cells through AMPK and Akt/mTOR signaling pathways. • Both LCD and its glucoside showed in vivo anti-colorectal cancer activities.

A novel way to grow hemozoin-like crystals in vitro and its use to screen for hemozoin inhibiting antimalarial compounds.

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Vincent Thomas

Full Text Available BACKGROUND: Hemozoin crystals are normally formed in vivo by Plasmodium parasites to detoxify free heme released after hemoglobin digestion during its intraerythrocytic stage. Inhibition of hemozoin formation by various drugs results in free heme concentration toxic for the parasites. As a consequence, in vitro assays have been developed to screen and select candidate antimalarial drugs based on their capacity to inhibit hemozoin formation. In this report we describe new ways to form hemozoin-like crystals that were incidentally discovered during research in the field of prion inactivation. METHODS: We investigated the use of a new assay based on naturally occurring "self-replicating" particles and previously described as presenting resistance to decontamination comparable to prions. The nature of these particles was determined using electron microscopy, Maldi-Tof analysis and X-ray diffraction. They were compared to synthetic hemozoin and to hemozoin obtained from Plasmodium falciparum. We then used the assay to evaluate the capacity of various antimalarial and anti-prion compounds to inhibit "self-replication" (crystallisation of these particles. RESULTS: We identified these particles as being similar to ferriprotoporphyrin IX crystal and confirmed the ability of these particles to serve as nuclei for growth of new hemozoin-like crystals (HLC. HLC are morphologically similar to natural and synthetic hemozoin. Growth of HLC in a simple assay format confirmed inhibition by quinolines antimalarials at potencies described in the literature. Interestingly, artemisinins and tetracyclines also seemed to inhibit HLC growth. CONCLUSIONS: The described HLC assay is simple and easy to perform and may have the potential to be used as an additional tool to screen antimalarial drugs for their hemozoin inhibiting activity. As already described by others, drugs that inhibit hemozoin crystal formation have also the potential to inhibit misfolded proteins

Celastrol inhibits chondrosarcoma proliferation, migration and invasion through suppression CIP2A/c-MYC signaling pathway

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Jinhui Wu

2017-05-01

Full Text Available Chondrosarcomas (CS is the second most frequent tumors of cartilage origin. A small compound extracted from Thunder God Vine (Tripterygium wilfordii Hook. F. called celastrol can directly bound CIP2A protein and effectively inhibit cell proliferation and induce apoptosis in several cancer cells. However, little knowledge is concern about the important role of CIP2A in CS patients and the therapeutic value of celastrol on CS. Our results showed that CIP2A and c-MYC were verified to be oncoproteins by detecting their mRNA and protein expression in 10 human CS tissues by qRT-PCR and Western blots. After treatment of celastrol, the proliferation, migration and invasion were significantly inhibited; whereas the apoptosis was largely induced in human CS cell lines. In addition, celastrol inhibited the expression of CIP2A, c-MYC, and suppressed apoptotic proteins BAX and caspase-8 in human CS cells, on the other hand, it induced the expression of antiapoptotic protein Bcl-2. Finally, knockdown of CIP2A also inhibited the migration and invasion and induced apoptosis of human CS cells. To sum up, we found that celastrol had effects on inhibiting proliferation, migration, invasion and inducing apoptosis through suppression CIP2A/c-MYC signaling pathway in vitro, which may provide a new therapeutic regimen for CS.

Green tea polyphenol epigallocatechin-3-gallate inhibits advanced glycation end product-induced expression of tumor necrosis factor-alpha and matrix metalloproteinase-13 in human chondrocytes.

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Rasheed, Zafar; Anbazhagan, Arivarasu N; Akhtar, Nahid; Ramamurthy, Sangeetha; Voss, Frank R; Haqqi, Tariq M

2009-01-01

The major risk factor for osteoarthritis (OA) is aging, but the mechanisms underlying this risk are only partly understood. Age-related accumulation of advanced glycation end products (AGEs) can activate chondrocytes and induce the production of proinflammatory cytokines and matrix metalloproteinases (MMPs). In the present study, we examined the effect of epigallocatechin-3-gallate (EGCG) on AGE-modified-BSA (AGE-BSA)-induced activation and production of TNFalpha and MMP-13 in human OA chondrocytes. Human chondrocytes were derived from OA cartilage by enzymatic digestion and stimulated with in vitro-generated AGE-BSA. Gene expression of TNFalpha and MMP-13 was measured by quantitative RT-PCR. TNFalpha protein in culture medium was determined using cytokine-specific ELISA. Western immunoblotting was used to analyze the MMP-13 production in the culture medium, phosphorylation of mitogen-activated protein kinases (MAPKs), and the activation of NF-kappaB. DNA binding activity of NF-kappaB p65 was determined using a highly sensitive and specific ELISA. IkappaB kinase (IKK) activity was determined using an in vitro kinase activity assay. MMP-13 activity in the culture medium was assayed by gelatin zymography. EGCG significantly decreased AGE-stimulated gene expression and production of TNFalpha and MMP-13 in human chondrocytes. The inhibitory effect of EGCG on the AGE-BSA-induced expression of TNFalpha and MMP-13 was mediated at least in part via suppression of p38-MAPK and JNK activation. In addition, EGCG inhibited the phosphorylating activity of IKKbeta kinase in an in vitro activity assay and EGCG inhibited the AGE-mediated activation and DNA binding activity of NF-kappaB by suppressing the degradation of its inhibitory protein IkappaBalpha in the cytoplasm. These novel pharmacological actions of EGCG on AGE-BSA-stimulated human OA chondrocytes provide new suggestions that EGCG or EGCG-derived compounds may inhibit cartilage degradation by suppressing AGE

Inhibition of platelet [3H]- imipramine binding by human plasma protein fractions

International Nuclear Information System (INIS)

Strijewski, A.; Chudzik, J.; Tang, S.W.

1988-01-01

Inhibition of high-affinity [ 3 H]-imipramine binding to platelet membranes by human plasma fractions and isolated plasma proteins was investigated. Several plasma proteins were found to contribute to the observed apparent inhibition and this contribution was assessed in terms of inhibitor units. Alpha 1 acid glycoprotein, high density and low density lipoprotein, IgG and α 1 -antitrypsin were identified as effective non-specific inhibitors. Alpha-1-acid glycoprotein was confirmed to be the most potent plasma protein inhibitor. Cohn fractions were evaluated for the presence of the postulated endocoid of [ 3 H]-imipramine binding site

Structure-Based Design and Synthesis of a Small Molecule that Exhibits Anti-inflammatory Activity by Inhibition of MyD88-mediated Signaling to Bacterial Toxin Exposure.

Science.gov (United States)

Alam, Shahabuddin; Javor, Sacha; Degardin, Melissa; Ajami, Dariush; Rebek, Mitra; Kissner, Teri L; Waag, David M; Rebek, Julius; Saikh, Kamal U

2015-08-01

Both Gram-positive and Gram-negative pathogens or pathogen-derived components, such as staphylococcal enterotoxins (SEs) and endotoxin (LPS) exposure, activate MyD88-mediated pro-inflammatory cellular immunity for host defense. However, dysregulated MyD88-mediated signaling triggers exaggerated immune response that often leads to toxic shock and death. Previously, we reported a small molecule compound 1 mimicking BB-loop structure of MyD88 was capable of inhibiting pro-inflammatory response to SEB exposure in mice. In this study, we designed a dimeric structure compound 4210 covalently linked with compound 1 by a non-polar cyclohexane linker which strongly inhibited the production of pro-inflammatory cytokines in human primary cells to SEB (IC50 1-50 μm) or LPS extracted from Francisella tularensis, Escherichia coli, or Burkholderia mallei (IC50 10-200 μm). Consistent with cytokine inhibition, in a ligand-induced cell-based reporter assay, compound 4210 inhibited Burkholderia mallei or LPS-induced MyD88-mediated NF-kB-dependent expression of reporter activity (IC50 10-30 μm). Furthermore, results from a newly expressed MyD88 revealed that 4210 inhibited MyD88 dimer formation which is critical for pro-inflammatory signaling. Importantly, a single administration of compound 4210 in mice showed complete protection from lethal toxin challenge. Collectively, these results demonstrated that compound 4210 inhibits toxin-induced inflated pro-inflammatory immune signaling, thus displays a potential bacterial toxin therapeutic. © 2014 John Wiley & Sons A/S.

Acrylamide: inhibition of formation in processed food and mitigation of toxicity in cells, animals, and humans.

Science.gov (United States)

Friedman, Mendel

2015-06-01

Potentially toxic acrylamide is largely derived from the heat-inducing reactions between the amino group of the amino acid asparagine and carbonyl groups of glucose and fructose in plant-derived foods including cereals, coffees, almonds, olives, potatoes, and sweet potatoes. This review surveys and consolidates the following dietary aspects of acrylamide: distribution in food, exposure and consumption by diverse populations, reduction of the content in different food categories, and mitigation of adverse in vivo effects. Methods to reduce acrylamide levels include selecting commercial food with a low acrylamide content, selecting cereal and potato varieties with low levels of asparagine and reducing sugars, selecting processing conditions that minimize acrylamide formation, adding food-compatible compounds and plant extracts to food formulations before processing that inhibit acrylamide formation during processing of cereal products, coffees, teas, olives, almonds, and potato products, and reducing multiorgan toxicity (antifertility, carcinogenicity, neurotoxicity, teratogenicity). The herein described observations and recommendations are of scientific interest for food chemistry, pharmacology, and toxicology, but also have the potential to benefit nutrition, food safety, and human health.

Monomethylarsonous acid inhibited endogenous cholesterol biosynthesis in human skin fibroblasts

Energy Technology Data Exchange (ETDEWEB)

Guo, Lei [Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521-0403 (United States); Xiao, Yongsheng [Department of Chemistry, University of California, Riverside, CA 92521-0403 (United States); Wang, Yinsheng, E-mail: yinsheng.wang@ucr.edu [Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521-0403 (United States); Department of Chemistry, University of California, Riverside, CA 92521-0403 (United States)

2014-05-15

Human exposure to arsenic in drinking water is a widespread public health concern, and such exposure is known to be associated with many human diseases. The detailed molecular mechanisms about how arsenic species contribute to the adverse human health effects, however, remain incompletely understood. Monomethylarsonous acid [MMA(III)] is a highly toxic and stable metabolite of inorganic arsenic. To exploit the mechanisms through which MMA(III) exerts its cytotoxic effect, we adopted a quantitative proteomic approach, by coupling stable isotope labeling by amino acids in cell culture (SILAC) with LC-MS/MS analysis, to examine the variation in the entire proteome of GM00637 human skin fibroblasts following acute MMA(III) exposure. Among the ∼ 6500 unique proteins quantified, ∼ 300 displayed significant changes in expression after exposure with 2 μM MMA(III) for 24 h. Subsequent analysis revealed the perturbation of de novo cholesterol biosynthesis, selenoprotein synthesis and Nrf2 pathways evoked by MMA(III) exposure. Particularly, MMA(III) treatment resulted in considerable down-regulation of several enzymes involved in cholesterol biosynthesis. In addition, real-time PCR analysis showed reduced mRNA levels of select genes in this pathway. Furthermore, MMA(III) exposure contributed to a distinct decline in cellular cholesterol content and significant growth inhibition of multiple cell lines, both of which could be restored by supplementation of cholesterol to the culture media. Collectively, the present study demonstrated that the cytotoxicity of MMA(III) may arise, at least in part, from the down-regulation of cholesterol biosynthesis enzymes and the resultant decrease of cellular cholesterol content. - Highlights: • MMA(III)-induced perturbation of the entire proteome of GM00637 cells is studied. • Quantitative proteomic approach revealed alterations of multiple cellular pathways. • MMA(III) inhibits de novo cholesterol biosynthesis. • MMA

Compounds from Terminalia mantaly L. (Combretaceae Stem Bark Exhibit Potent Inhibition against Some Pathogenic Yeasts and Enzymes of Metabolic Significance

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Marthe Aimée Tchuente Tchuenmogne

2017-01-01

Full Text Available Background: Pathogenic yeasts resistance to current drugs emphasizes the need for new, safe, and cost-effective drugs. Also, new inhibitors are needed to control the effects of enzymes that are implicated in metabolic dysfunctions such as cancer, obesity, and epilepsy. Methods: The anti-yeast extract from Terminalia mantaly (Combretaceae was fractionated and the structures of the isolated compounds established by means of spectroscopic analysis and comparison with literature data. Activity was assessed against Candida albicans, C. parapsilosis and C. krusei using the microdilution method, and against four enzymes of metabolic significance: glucose-6-phosphate dehydrogenase, human erythrocyte carbonic anhydrase I and II, and glutathione S-transferase. Results: Seven compounds, 3,3′-di-O-methylellagic acid 4′-O-α-rhamnopyranoside; 3-O-methylellagic acid; arjungenin or 2,3,19,23-tetrahydroxyolean-12-en-28-oïc acid; arjunglucoside or 2,3,19,23-tetrahydroxyolean-12-en-28-oïc acid glucopyranoside; 2α,3α,24-trihydroxyolean-11,13(18-dien-28-oïc acid; stigmasterol; and stigmasterol 3-O-β-d-glucopyranoside were isolated from the extract. Among those, 3,3′-di-O-methylellagic acid 4′-O-α-rhamnopyranoside, 3-O-methylellagic acid, and arjunglucoside showed anti-yeast activity comparable to that of reference fluconazole with minimal inhibitory concentrations (MIC below 32 µg/mL. Besides, Arjunglucoside potently inhibited the tested enzymes with 50% inhibitory concentrations (IC50 below 4 µM and inhibitory constant (Ki <3 µM. Conclusions: The results achieved indicate that further SAR studies will likely identify potent hit derivatives that should subsequently enter the drug development pipeline.

Inhibition of β-Secretase Activity by Monoterpenes, Sesquiterpenes, and C13 Norisoprenoids.

Science.gov (United States)

Marumoto, Shinsuke; Okuno, Yoshiharu; Miyazawa, Mitsuo

2017-08-01

Inhibition of β-secretase (BACE1) is currently regarded as the leading treatment strategy for Alzheimer's disease. In the present study, we aimed to screen the in vitro inhibitory activity of 80 types of aroma compounds (monoterpenes, sesquiterpenes, and C 13 norisoprenoids), including plant-based types, at a 200-μM concentration against a recombinant human BACE1. The results showed that the most potent inhibitor of BACE1 was geranyl acetone followed by (+)-camphor, (-)-fenchone, (+)-fenchone, and (-)-camphor with the half-maximal inhibitory concentration (IC 50 ) values of 51.9 ± 3.9, 95.9 ± 11.0, 106.3 ± 14.9, 117.0 ± 18.6, and 134.1 ± 16.4 μM, respectively. Furthermore, the mechanism of inhibition of BACE1 by geranyl acetone was analyzed using Dixon kinetics plus Cornish-Bowden plots, which revealed mixed-type mode. Therefore aroma compounds may be used as potential lead molecules for designing anti-BACE1 agents.

Antiviral lead compounds from marine sponges

KAUST Repository

Sagar, Sunil

2010-10-11

Marine sponges are currently one of the richest sources of pharmacologically active compounds found in the marine environment. These bioactive molecules are often secondary metabolites, whose main function is to enable and/or modulate cellular communication and defense. They are usually produced by functional enzyme clusters in sponges and/or their associated symbiotic microorganisms. Natural product lead compounds from sponges have often been found to be promising pharmaceutical agents. Several of them have successfully been approved as antiviral agents for clinical use or have been advanced to the late stages of clinical trials. Most of these drugs are used for the treatment of human immunodeficiency virus (HIV) and herpes simplex virus (HSV). The most important antiviral lead of marine origin reported thus far is nucleoside Ara-A (vidarabine) isolated from sponge Tethya crypta. It inhibits viral DNA polymerase and DNA synthesis of herpes, vaccinica and varicella zoster viruses. However due to the discovery of new types of viruses and emergence of drug resistant strains, it is necessary to develop new antiviral lead compounds continuously. Several sponge derived antiviral lead compounds which are hopedto be developed as future drugs are discussed in this review. Supply problems are usually the major bottleneck to the development of these compounds as drugs during clinical trials. However advances in the field of metagenomics and high throughput microbial cultivation has raised the possibility that these techniques could lead to the cost-effective large scale production of such compounds. Perspectives on biotechnological methods with respect to marine drug development are also discussed. 2010 by the authors; licensee MDPI.

Na+/K+-ATPase: Activity and inhibition

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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.

Gemcitabine inhibits proliferation and induces apoptosis in human pancreatic cancer PANC-1 cells.

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Yong-Xian, Gui; Xiao-Huan, Li; Fan, Zhang; Guo-Fang, Tian

2016-10-01

The aim of the study is to investigate the underlying molecular mechanisms by which gemcitabine (gem) inhibits proliferation and induces apoptosis in human pancreatic cancer PANC-1 cells in vitro. After PANC-1 cells had been treated by indicated concentration (0, 5, and 25 mg/L) of gem for 48 h, cell proliferation was evaluated by 3'-(4, 5 dimethyl-thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay; cell morphology was observed by transmission electron microscopy; Expression of c-IAP2 and Bcl-2 proteins was analyzed by Western blot; the activity of caspase-3 and -9 was detected by spectrophotometry. Gem significantly inhibited cell proliferation and could induce apoptosis of human pancreatic cancer PANC-1 cells, with a dose-dependent manner. Western blot analysis showed that gem significantly reduced c-IAP2 and Bcl-2 proteins expression level (P PANC-1 cells. Gem could induce apoptosis of human pancreatic cancer PANC-1 cells, probably through downregulating c-IAP2 and Bcl-2 expression levels, and at the same time activating caspase-3 and -9.

Saw palmetto extracts potently and noncompetitively inhibit human alpha1-adrenoceptors in vitro.

Science.gov (United States)

Goepel, M; Hecker, U; Krege, S; Rübben, H; Michel, M C

1999-02-15

We wanted to test whether phytotherapeutic agents used in the treatment of lower urinary tract symptoms have alpha1-adrenoceptor antagonistic properties in vitro. Preparations of beta-sitosterol and extracts of stinging nettle, medicinal pumpkin, and saw palmetto were obtained from several pharmaceutical companies. They were tested for their ability to inhibit [3H]tamsulosin binding to human prostatic alpha1-adrenoceptors and [3H]prazosin binding to cloned human alpha1A- and alpha1B-adrenoceptors. Inhibition of phenylephrine-stimulated [3H]inositol phosphate formation by cloned receptors was also investigated. Up to the highest concentration which could be tested, preparations of beta-sitosterol, stinging nettle, and medicinal pumpkin were without consistent inhibitory effect in all assays. In contrast, all tested saw palmetto extracts inhibited radioligand binding to human alpha1-adrenoceptors and agonist-induced [3H]inositol phosphate formation. Saturation binding experiments in the presence of a single saw palmetto extract concentration indicated a noncompetitive antagonism. The relationship between active concentrations in vitro and recommended therapeutic doses for the saw palmetto extracts was slightly lower than that for several chemically defined alpha1-adrenoceptor antagonists. Saw palmetto extracts have alpha1-adrenoceptor-inhibitory properties. If bioavailability and other pharmacokinetic properties of these ingredients are similar to those of the chemically defined alpha1-adrenoceptor antagonists, alpha1-adrenoceptor antagonism might be involved in the therapeutic effects of these extracts in patients with lower urinary tract symptoms suggestive of benign prostatic obstruction.

Ebselen Reversibly Inhibits Human Glutamate Dehydrogenase at the Catalytic Site.

Science.gov (United States)

Jin, Yanhong; Li, Di; Lu, Shiying; Zhao, Han; Chen, Zhao; Hou, Wei; Ruan, Benfang Helen

Human glutamate dehydrogenase (GDH) plays an important role in neurological diseases, tumor metabolism, and hyperinsulinism-hyperammonemia syndrome (HHS). However, there are very few inhibitors known for human GDH. Recently, Ebselen was reported to crosslink with Escherichia coli GDH at the active site cysteine residue (Cys321), but the sequence alignment showed that the corresponding residue is Ala329 in human GDH. To investigate whether Ebselen could be an inhibitor for human GDH, we cloned and expressed an N-terminal His-tagged human GDH in E. coli. The recombinant human GDH enzyme showed expected properties such as adenosine diphosphate activation and nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate dual recognition. Further, we developed a 2-(3-(2-methoxy-4-nitrophenyl)-2-(4-nitrophenyl)-2H-tetrazol-3-ium-5-yl) benzenesulfonate sodium salt (EZMTT)-based assay for human GDH, which was highly sensitive and is suitable for high-throughput screening for potent GDH inhibitors. In addition, ForteBio binding assays demonstrated that Ebselen is a reversible active site inhibitor for human GDH. Since Ebselen is a multifunctional organoselenium compound in Phase III clinical trials for inflammation, an Ebselen-based GDH inhibitor might be valuable for future drug discovery for HHS patients.

Anti-helminth compound niclosamide downregulates Wnt Signaling and elicits antitumor responses in tumors with activating APC mutations

Science.gov (United States)

Osada, Takuya; Chen, Minyong; Yang, Xiao Yi; Spasojevic, Ivan; Vandeusen, Jeffrey B.; Hsu, David; Clary, Bryan M.; Clay, Timothy M.; Chen, Wei; Morse, Michael A.; Lyerly, H. Kim

2011-01-01

Wnt/β-catenin pathway activation caused by APC mutations occurs in approximately 80% of sporadic colorectal cancers. The anti-helminth compound niclosamide downregulates components of the Wnt pathway, specifically Dishevelled-2 (Dvl2) expression, resulting in diminished downstream β-catenin signaling. In this study, we determined if niclosamide could inhibit the Wnt/ β-catenin pathway in human colorectal cancers and whether its inhibition might elicit antitumor effects in the presence of APC mutations. We found that niclosamide inhibited Wnt/ β-catenin pathway activation, downregulated Dvl2, decreased downstream β-catenin signaling and exerted anti-proliferative effects in human colon cancer cell lines and colorectal cancer cells isolated by surgical resection of metastatic disease, regardless of mutations in APC. In contrast, inhibition of NF-κB or mTOR did not exert similar anti-proliferative effects in these colorectal cancer model systems. In mice implanted with human colorectal cancer xenografts, orally administered niclosamide was well tolerated, achieved plasma and tumor levels associated with biologic activity and led to tumor control. Our findings support clinical explorations to reposition niclosamide for treatment of colorectal cancer. PMID:21531761

Naloxone inhibits superoxide but not enzyme release by human neutrophils

Energy Technology Data Exchange (ETDEWEB)

Simpkins, C.; Alailima, S.; Tate, E.

1986-03-01

The release of toxic oxygen metabolites and enzymes by phagocytic cells is thought to play a role in the multisystemic tissue injury of sepsis. Naloxone protects septic animals. We have found that at concentrations administered to animals (10/sup -7/ to 10/sup -4/M), naloxone inhibited (p < .001) the release of superoxide (O/sub 2//sup -/) by human neutrophils (HN), stimulated with N-formyl methionyl leucyl phenylalanine (FMLP). Naloxone had no effect on cell viability. Maximum inhibition was 65% of the total O/sub 2//sup -/ released (13.1 nMoles/8 min/320,000 cells). FMLP-stimulated release of beta-glucoronidase or lysozyme was not altered by naloxone. Naloxone had no effect on the binding of /sup 3/H FMLP to HN. Using /sup 3/H naloxone and various concentrations of unlabeled naloxone higher affinity (K/sub D/ = 12nM) and lower affinity (K/sub D/ = 4.7 x 10/sup -5/) binding sites were detected. The K/sub D/ of the low affinity site corresponded to the ED/sub 50/ for naloxone inhibition of O/sub 2//sup -/ (1 x 10/sup -5/M). Binding to this low affinity site was decreased by (+) naloxone, beta-endorphin and N acetyl beta-endorphin, but not by leu-enkephalin, thyrotropin releasing factor, prostaglandin D/sub 2/ or E/sub 2/. Conclusions: (1) naloxone inhibits FMLP-stimulated O/sub 2/ but not enzyme release, (2) this inhibition is not due to alteration of FMLP receptor binding, (3) naloxone may act via a low affinity binding site which is ligand specific, and (4) a higher affinity receptor is present on HN.

Corrosion inhibition of mild steel in acidic media using newly synthesized heterocyclic organic molecules: Correlation between inhibition efficiency and chemical structure

Energy Technology Data Exchange (ETDEWEB)

Ouici, H. B., E-mail: ouici.houari@yahoo.fr; Guendouzi, A., E-mail: guendouzzi@yahoo.fr [Departement of Chimistry, Faculty of Sciences, University of Saïda (Algeria); Benali, O. [Department of Biology, Faculty of Science, University of Saida (Algeria)

2015-03-30

The corrosion inhibition of mild steel in 5% HCl solutions by some new synthesized organic compounds namely 3-(2-methoxyphenyl) 5-mercapto-1. 2. 4-triazole (2-MMT), 3-(3-methoxyphenyl) 5-mercapto-1. 2. 4-triazole (3-MMT) and 3-(2-hydroxyphenyl) 5-mercapto-1. 2. 4-triazole (2-HMT) was investigated using weight loss and potentiostatic polarization techniques. These measurements reveal that the inhibition efficiency obtained by these compounds increased by increasing their concentration. The inhibition efficiency follows the order 2-MMT >3-MMT >2-HMT. Polarization studies show that these compounds are of the mixed type but dominantly act as a cathodic inhibitors for mild steel in 5% HCl solutions. These inhibitors function through adsorption following Langmuir isotherm. Activation energy and Gibbs free energy for adsorption of inhibitors are calculated. Molecular modeling has been conducted to correlate the corrosion inhibition properties with the calculated quantum chemical parameters.

In vitro atrazine-exposure inhibits human natural killer cell lytic granule release

International Nuclear Information System (INIS)

Rowe, Alexander M.; Brundage, Kathleen M.; Barnett, John B.

2007-01-01

The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test this hypothesis, flow cytometry and fluorescent microscopy were employed to analyze NK cell-target cell co-cultures following atrazine exposure. These assays demonstrated no significant decrease in the level of target cell binding. However, the levels of NK intracellular lytic protein retained and the amount of lytic protein released were assessed following a 4-h incubation with K562 target cells. The relative level of intracellular lytic protein was 25-50% higher, and the amount of lytic protein released was 55-65% less in atrazine-treated cells than vehicle-treated cells following incubation with the target cells. These results indicate that ATR exposure inhibits the ability of NK cells to lyse target cells by blocking lytic granule release without affecting the ability of the NK cell to form stable conjugates with target cells

Restoration of adenosine deaminase-deficient human thymocyte development in vitro by inhibition of deoxynucleoside kinases.

Science.gov (United States)

Joachims, Michelle L; Marble, Patrick A; Laurent, Aletha B; Pastuszko, Peter; Paliotta, Marco; Blackburn, Michael R; Thompson, Linda F

2008-12-01

Mutations in the gene encoding adenosine deaminase (ADA), a purine salvage enzyme, lead to immunodeficiency in humans. Although ADA deficiency has been analyzed in cell culture and murine models, information is lacking concerning its impact on the development of human thymocytes. We have used chimeric human/mouse fetal thymic organ culture to study ADA-deficient human thymocyte development in an "in vivo-like" environment where toxic metabolites accumulate in situ. Inhibition of ADA during human thymocyte development resulted in a severe reduction in cellular expansion as well as impaired differentiation, largely affecting mature thymocyte populations. Thymocyte differentiation was not blocked at a discrete stage; rather, the paucity of mature thymocytes was due to the induction of apoptosis as evidenced by activation of caspases and was accompanied by the accumulation of intracellular dATP. Inhibition of adenosine kinase and deoxycytidine kinase prevented the accumulation of dATP and restored thymocyte differentiation and proliferation. Our work reveals that multiple deoxynucleoside kinases are involved in the phosphorylation of deoxyadenosine when ADA is absent, and suggests an alternate therapeutic strategy for treatment of ADA-deficient patients.

Multiple cationic amphiphiles induce a Niemann-Pick C phenotype and inhibit Ebola virus entry and infection.

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Charles J Shoemaker

Full Text Available Ebola virus (EBOV is an enveloped RNA virus that causes hemorrhagic fever in humans and non-human primates. Infection requires internalization from the cell surface and trafficking to a late endocytic compartment, where viral fusion occurs, providing a conduit for the viral genome to enter the cytoplasm and initiate replication. In a concurrent study, we identified clomiphene as a potent inhibitor of EBOV entry. Here, we screened eleven inhibitors that target the same biosynthetic pathway as clomiphene. From this screen we identified six compounds, including U18666A, that block EBOV infection (IC(50 1.6 to 8.0 µM at a late stage of entry. Intriguingly, all six are cationic amphiphiles that share additional chemical features. U18666A induces phenotypes, including cholesterol accumulation in endosomes, associated with defects in Niemann-Pick C1 protein (NPC1, a late endosomal and lysosomal protein required for EBOV entry. We tested and found that all six EBOV entry inhibitors from our screen induced cholesterol accumulation. We further showed that higher concentrations of cationic amphiphiles are required to inhibit EBOV entry into cells that overexpress NPC1 than parental cells, supporting the contention that they inhibit EBOV entry in an NPC1-dependent manner. A previously reported inhibitor, compound 3.47, inhibits EBOV entry by blocking binding of the EBOV glycoprotein to NPC1. None of the cationic amphiphiles tested had this effect. Hence, multiple cationic amphiphiles (including several FDA approved agents inhibit EBOV entry in an NPC1-dependent fashion, but by a mechanism distinct from that of compound 3.47. Our findings suggest that there are minimally two ways of perturbing NPC1-dependent pathways that can block EBOV entry, increasing the attractiveness of NPC1 as an anti-filoviral therapeutic target.

Gigantol Inhibits Epithelial to Mesenchymal Process in Human Lung Cancer Cells

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Thitita Unahabhokha

2016-01-01

Full Text Available Lung cancer remains a leading public health problem as evidenced by its increasing death rate. The main cause of death in lung cancer patients is cancer metastasis. The metastatic behavior of lung cancer cells becomes enhanced when cancer cells undergo epithelial to mesenchymal transition (EMT. Gigantol, a bibenzyl compound extracted from the Thai orchid, Dendrobium draconis, has been shown to have promising therapeutic potential against cancer cells, which leads to the hypothesis that gigantol may be able to inhibit the fundamental EMT process in cancer cells. This study has demonstrated for the first time that gigantol possesses the ability to suppress EMT in non-small cell lung cancer H460 cells. Western blot analysis has revealed that gigantol attenuates the activity of ATP-dependent tyrosine kinase (AKT, thereby inhibiting the expression of the major EMT transcription factor, Slug, by both decreasing its transcription and increasing its degradation. The inhibitory effects of gigantol on EMT result in a decrease in the level of migration in H460 lung cancer cells. The results of this study emphasize the potential of gigantol for further development against lung cancer metastasis.

Inhibition of the differentiation of monocyte-derived dendritic cells by human gingival fibroblasts.

Directory of Open Access Journals (Sweden)

Sylvie Séguier

Full Text Available We investigated whether gingival fibroblasts (GFs can modulate the differentiation and/or maturation of monocyte-derived dendritic cells (DCs and analyzed soluble factors that may be involved in this immune modulation. Experiments were performed using human monocytes in co-culture with human GFs in Transwell® chambers or using monocyte cultures treated with conditioned media (CM from GFs of four donors. The four CM and supernatants from cell culture were assayed by ELISA for cytokines involved in the differentiation of dendritic cells, such as IL-6, VEGF, TGFβ1, IL-13 and IL-10. The maturation of monocyte-derived DCs induced by LPS in presence of CM was also studied. Cell surface phenotype markers were analyzed by flow cytometry. In co-cultures, GFs inhibited the differentiation of monocyte-derived DCs and the strength of this blockade correlated with the GF/monocyte ratio. Conditioned media from GFs showed similar effects, suggesting the involvement of soluble factors produced by GFs. This inhibition was associated with a lower stimulatory activity in MLR of DCs generated with GFs or its CM. Neutralizing antibodies against IL-6 and VEGF significantly (P<0.05 inhibited the inhibitory effect of CM on the differentiation of monocytes-derived DCs and in a dose dependent manner. Our data suggest that IL-6 is the main factor responsible for the inhibition of DCs differentiation mediated by GFs but that VEGF is also involved and constitutes an additional mechanism.

Novel 11β-hydroxysteroid dehydrogenase 1 inhibitors reduce cortisol levels in keratinocytes and improve dermal collagen content in human ex vivo skin after exposure to cortisone and UV.

Directory of Open Access Journals (Sweden)

Stéphanie M Boudon

Full Text Available Activity and selectivity assessment of new bi-aryl amide 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1 inhibitors, prepared in a modular manner via Suzuki cross-coupling, are described. Several compounds inhibiting 11β-HSD1 at nanomolar concentrations were identified. Compounds 2b, 3e, 7b and 12e were shown to selectively inhibit 11β-HSD1 over 11β-HSD2, 17β-HSD1 and 17β-HSD2. These inhibitors also potently inhibited 11β-HSD1 activity in intact HEK-293 cells expressing the recombinant enzyme and in intact primary human keratinocytes expressing endogenous 11β-HSD1. Moreover, compounds 2b, 3e and 12e were tested for their activity in human skin biopsies. They were able to prevent, at least in part, both the cortisone- and the UV-mediated decreases in collagen content. Thus, inhibition of 11β-HSD1 by these compounds can be further investigated to delay or prevent UV-mediated skin damage and skin aging.

1082-39, an analogue of sorafenib, inhibited human cancer cell growth more potently than sorafenib.

Science.gov (United States)

Chu, Jia-Hui; Zhao, Cui-Rong; Song, Zhi-Yu; Wang, Rui-Qi; Qin, Yi-Zhuo; Li, Wen-Bao; Qu, Xian-Jun

2014-04-01

1082-39, an analogue of sorafenib, is a derivative of indazole diarylurea. We evaluated the activity of 1082-39 against human cancer cell growth. Its effects and mechanisms of action were then compared with those of sorafenib. The experiments were performed in human melanoma M21 cells. Cell viability was estimated by using the colorimetric assay. Annexin V-FITC/PI staining assay was used to recognize the apoptotic cells. Further analysis of the mitochondria membrane potential (MMP) was performed by the JC-1 fluorescence probe staining. The levels of apoptotic proteins and kinases related to cancer proliferation were determined by western blotting assay. 1082-39 possessed the activity against cancer cell proliferation with time- and dose-dependent manner. 1082-39 induced M21 cell to apoptosis, showing the increase of annexin V-FITC/PI staining cells, the MMP collapse and releasing cytochrome c from mitochondria. Western blotting analysis showed the activation of the mitochondria-mediated intrinsic pathway, showing the increase of cleaved caspase-9, cleaved caspase-3 and cleaved PARP. Statistical analysis suggested that 1082-39 possessed greater activities than sorafenib in the inhibition of M21 proliferation and induction of apoptosis. These effects of 1082-39 might arise from its activity of regulation the PI3K/Akt and Wnt/β-catenin signaling pathways. 1082-39 is a promising candidate compound which could develop as a potent anticancer agent. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Inhibition of several enzymes by gold compounds. II. beta-Glucuronidase, acid phosphatase and L-malate dehydrogenase by sodium thiomalatoraurate (I), sodium thiosulfatoaurate (I) and thioglucosoaurate (I).

Science.gov (United States)

Lee, M T; Ahmed, T; Haddad, R; Friedman, M E

1989-01-01

Bovine liver beta-D-glucuronide glucuronohydrolase, EC 3.2.1.32), wheat germ acid phosphatase (orthophosphoric monoesterphosphohydrolase, EC 3.1.3.2) and bovine liver L-malate dehydrogenase (L-malate: NAD oxidoreductase, EC 1.1.1.37) were inhibited by a series of gold (I) complexes that have been used as anti-inflammatory drugs. Both sodium thiosulfatoaurate (I) (Na AuTs) and sodium thiomalatoraurate (NaAuTM) effectively inhibited all three enzymes, while thioglucosoaurate (I) (AuTG) only inhibited L-malate dehydrogenase. The equilibrium constants (K1) ranged from nearly 4000 microM for the NaAuTM-beta-glucuronidase interaction to 24 microM for the NaAuTS-beta-glucuronidase interaction. The rate of covalent bond formation (kp) ranged from 0.00032 min-1 for NaAuTM-beta-glucuronidase formation to 1.7 min-1 for AuTG-L-malate dehydrogenase formation. The equilibrium data shows that the gold (I) drugs bind by several orders lower than the gold (III) compounds, suggesting a significantly stronger interaction between the more highly charged gold ion and the enzyme. Yet the rate of covalent bond formation depends as much on the structure of the active site as upon the lability of the gold-ligand bond. It was also observed that the more effective the gold inhibition the more toxic the compound.

Study on the Mechanisms of Active Compounds in Traditional Chinese Medicine for the Treatment of Influenza Virus by Virtual Screening.

Science.gov (United States)

Ai, Haixin; Wu, Xuewei; Qi, Mengyuan; Zhang, Li; Hu, Huan; Zhao, Qi; Zhao, Jian; Liu, Hongsheng

2018-06-01

In recent years, new strains of influenza virus such as H7N9, H10N8, H5N6 and H5N8 had continued to emerge. There was an urgent need for discovery of new anti-influenza virus drugs as well as accurate and efficient large-scale inhibitor screening methods. In this study, we focused on six influenza virus proteins that could be anti-influenza drug targets, including neuraminidase (NA), hemagglutinin (HA), matrix protein 1 (M1), M2 proton channel (M2), nucleoprotein (NP) and non-structural protein 1 (NS1). Structure-based molecular docking was utilized to identify potential inhibitors for these drug targets from 13144 compounds in the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform. The results showed that 56 compounds could inhibit more than two drug targets simultaneously. Further, we utilized reverse docking to study the interaction of these compounds with host targets. Finally, the 22 compound inhibitors could stably bind to host targets with high binding free energy. The results showed that the Chinese herbal medicines had a multi-target effect, which could directly inhibit influenza virus by the target viral protein and indirectly inhibit virus by the human target protein. This method was of great value for large-scale virtual screening of new anti-influenza virus compounds.

Striatal D1- and D2-type dopamine receptors are linked to motor response inhibition in human subjects.

Science.gov (United States)

Robertson, Chelsea L; Ishibashi, Kenji; Mandelkern, Mark A; Brown, Amira K; Ghahremani, Dara G; Sabb, Fred; Bilder, Robert; Cannon, Tyrone; Borg, Jacqueline; London, Edythe D

2015-04-15

Motor response inhibition is mediated by neural circuits involving dopaminergic transmission; however, the relative contributions of dopaminergic signaling via D1- and D2-type receptors are unclear. Although evidence supports dissociable contributions of D1- and D2-type receptors to response inhibition in rats and associations of D2-type receptors to response inhibition in humans, the relationship between D1-type receptors and response inhibition has not been evaluated in humans. Here, we tested whether individual differences in striatal D1- and D2-type receptors are related to response inhibition in human subjects, possibly in opposing ways. Thirty-one volunteers participated. Response inhibition was indexed by stop-signal reaction time on the stop-signal task and commission errors on the continuous performance task, and tested for association with striatal D1- and D2-type receptor availability [binding potential referred to nondisplaceable uptake (BPND)], measured using positron emission tomography with [(11)C]NNC-112 and [(18)F]fallypride, respectively. Stop-signal reaction time was negatively correlated with D1- and D2-type BPND in whole striatum, with significant relationships involving the dorsal striatum, but not the ventral striatum, and no significant correlations involving the continuous performance task. The results indicate that dopamine D1- and D2-type receptors are associated with response inhibition, and identify the dorsal striatum as an important locus of dopaminergic control in stopping. Moreover, the similar contribution of both receptor subtypes suggests the importance of a relative balance between phasic and tonic dopaminergic activity subserved by D1- and D2-type receptors, respectively, in support of response inhibition. The results also suggest that the stop-signal task and the continuous performance task use different neurochemical mechanisms subserving motor response inhibition. Copyright © 2015 the authors 0270-6474/15/355990-08$15.00/0.

Human metapneumovirus M2-2 protein inhibits innate immune response in monocyte-derived dendritic cells.

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Junping Ren

Full Text Available Human metapneumovirus (hMPV is a leading cause of lower respiratory infection in young children, the elderly and immunocompromised patients. Repeated hMPV infections occur throughout life. However, immune evasion mechanisms of hMPV infection are largely unknown. Recently, our group has demonstrated that hMPV M2-2 protein, an important virulence factor, contributes to immune evasion in airway epithelial cells by targeting the mitochondrial antiviral-signaling protein (MAVS. Whether M2-2 regulates the innate immunity in human dendritic cells (DC, an important family of immune cells controlling antigen presenting, is currently unknown. We found that human DC infected with a virus lacking M2-2 protein expression (rhMPV-ΔM2-2 produced higher levels of cytokines, chemokines and IFNs, compared to cells infected with wild-type virus (rhMPV-WT, suggesting that M2-2 protein inhibits innate immunity in human DC. In parallel, we found that myeloid differentiation primary response gene 88 (MyD88, an essential adaptor for Toll-like receptors (TLRs, plays a critical role in inducing immune response of human DC, as downregulation of MyD88 by siRNA blocked the induction of immune regulatory molecules by hMPV. Since M2-2 is a cytoplasmic protein, we investigated whether M2-2 interferes with MyD88-mediated antiviral signaling. We found that indeed M2-2 protein associated with MyD88 and inhibited MyD88-dependent gene transcription. In this study, we also identified the domains of M2-2 responsible for its immune inhibitory function in human DC. In summary, our results demonstrate that M2-2 contributes to hMPV immune evasion by inhibiting MyD88-dependent cellular responses in human DC.

Inhibition of recombinant human carboxylesterase 1 and 2 and monoacylglycerol lipase by chlorpyrifos oxon, paraoxon and methyl paraoxon

International Nuclear Information System (INIS)

Crow, J. Allen; Bittles, Victoria; Herring, Katye L.; Borazjani, Abdolsamad; Potter, Philip M.; Ross, Matthew K.

2012-01-01

Oxons are the bioactivated metabolites of organophosphorus insecticides formed via cytochrome P450 monooxygenase-catalyzed desulfuration of the parent compound. Oxons react covalently with the active site serine residue of serine hydrolases, thereby inactivating the enzyme. A number of serine hydrolases other than acetylcholinesterase, the canonical target of oxons, have been reported to react with and be inhibited by oxons. These off-target serine hydrolases include carboxylesterase 1 (CES1), CES2, and monoacylglycerol lipase. Carboxylesterases (CES, EC 3.1.1.1) metabolize a number of xenobiotic and endobiotic compounds containing ester, amide, and thioester bonds and are important in the metabolism of many pharmaceuticals. Monoglyceride lipase (MGL, EC 3.1.1.23) hydrolyzes monoglycerides including the endocannabinoid, 2-arachidonoylglycerol (2-AG). The physiological consequences and toxicity related to the inhibition of off-target serine hydrolases by oxons due to chronic, low level environmental exposures are poorly understood. Here, we determined the potency of inhibition (IC 50 values; 15 min preincubation, enzyme and inhibitor) of recombinant CES1, CES2, and MGL by chlorpyrifos oxon, paraoxon and methyl paraoxon. The order of potency for these three oxons with CES1, CES2, and MGL was chlorpyrifos oxon > paraoxon > methyl paraoxon, although the difference in potency for chlorpyrifos oxon with CES1 and CES2 did not reach statistical significance. We also determined the bimolecular rate constants (k inact /K I ) for the covalent reaction of chlorpyrifos oxon, paraoxon and methyl paraoxon with CES1 and CES2. Consistent with the results for the IC 50 values, the order of reactivity for each of the three oxons with CES1 and CES2 was chlorpyrifos oxon > paraoxon > methyl paraoxon. The bimolecular rate constant for the reaction of chlorpyrifos oxon with MGL was also determined and was less than the values determined for chlorpyrifos oxon with CES1 and CES2

Inhibition of recombinant human carboxylesterase 1 and 2 and monoacylglycerol lipase by chlorpyrifos oxon, paraoxon and methyl paraoxon

Energy Technology Data Exchange (ETDEWEB)

Crow, J. Allen; Bittles, Victoria; Herring, Katye L.; Borazjani, Abdolsamad [Center for Environmental Health Sciences, Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762 (United States); Potter, Philip M. [Department of Chemical Biology and Therapeutics, St. Jude Children' s Research Hospital, 332 N. Lauderdale, Memphis, TN 38105 (United States); Ross, Matthew K., E-mail: mross@cvm.msstate.edu [Center for Environmental Health Sciences, Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762 (United States)

2012-01-01

Oxons are the bioactivated metabolites of organophosphorus insecticides formed via cytochrome P450 monooxygenase-catalyzed desulfuration of the parent compound. Oxons react covalently with the active site serine residue of serine hydrolases, thereby inactivating the enzyme. A number of serine hydrolases other than acetylcholinesterase, the canonical target of oxons, have been reported to react with and be inhibited by oxons. These off-target serine hydrolases include carboxylesterase 1 (CES1), CES2, and monoacylglycerol lipase. Carboxylesterases (CES, EC 3.1.1.1) metabolize a number of xenobiotic and endobiotic compounds containing ester, amide, and thioester bonds and are important in the metabolism of many pharmaceuticals. Monoglyceride lipase (MGL, EC 3.1.1.23) hydrolyzes monoglycerides including the endocannabinoid, 2-arachidonoylglycerol (2-AG). The physiological consequences and toxicity related to the inhibition of off-target serine hydrolases by oxons due to chronic, low level environmental exposures are poorly understood. Here, we determined the potency of inhibition (IC{sub 50} values; 15 min preincubation, enzyme and inhibitor) of recombinant CES1, CES2, and MGL by chlorpyrifos oxon, paraoxon and methyl paraoxon. The order of potency for these three oxons with CES1, CES2, and MGL was chlorpyrifos oxon > paraoxon > methyl paraoxon, although the difference in potency for chlorpyrifos oxon with CES1 and CES2 did not reach statistical significance. We also determined the bimolecular rate constants (k{sub inact}/K{sub I}) for the covalent reaction of chlorpyrifos oxon, paraoxon and methyl paraoxon with CES1 and CES2. Consistent with the results for the IC{sub 50} values, the order of reactivity for each of the three oxons with CES1 and CES2 was chlorpyrifos oxon > paraoxon > methyl paraoxon. The bimolecular rate constant for the reaction of chlorpyrifos oxon with MGL was also determined and was less than the values determined for chlorpyrifos oxon with CES1

Cucurbitacin B inhibits human breast cancer cell proliferation through disruption of microtubule polymerization and nucleophosmin/B23 translocation

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Duangmano Suwit

2012-10-01

Full Text Available Abstract Background Cucurbitacin B, an oxygenated tetracyclic triterpenoid compound extracted from the Thai medicinal plant Trichosanthes cucumerina L., has been reported to have several biological activities including anti-inflammatory, antimicrobial and anticancer. Cucurbitacin B is great of interest because of its biological activity. This agent inhibits growth of various types of human cancer cells lines. Methods In this study, we explored the novel molecular response of cucurbitacin B in human breast cancer cells, MCF-7 and MDA-MB-231. The growth inhibitory effect of cucurbitacin B on breast cancer cells was assessed by MTT assay. The effects of cucurbitacin B on microtubules morphological structure and tubulin polymerization were analyzed using immunofluorescence technique and tubulin polymerization assay kit, respectively. Proteomic analysis was used to identify the target-specific proteins that involved in cucurbitacin B treatment. Some of the differentially expressed genes and protein products were validated by real-time RT-PCR and western blot analysis. Cell cycle distributions and apoptosis were investigated using flow cytometry. Results Cucurbitacin B exhibited strong antiproliferative effects against breast cancer cells in a dose-dependent manner. We show that cucurbitacin B prominently alters the cytoskeletal network of breast cancer cells, inducing rapid morphologic changes and improper polymerization of the microtubule network. Moreover, the results of 2D-PAGE, real-time RT-PCR, and western blot analysis revealed that the expression of nucleophosmin/B23 and c-Myc decreased markedly after cucurbitacin B treatment. Immunofluorescence microscopy showed that cucurbitacin B induced translocation of nucleophosmin/B23 from the nucleolus to nucleoplasm. Treatment with cucurbitacin B resulted in cell cycle arrest at G2/M phase and the enhancement of apoptosis. Conclusions Our findings suggest that cucurbitacin B may inhibit the

Organic compounds inhibiting S. epidermidis adhesion and biofilm formation

DEFF Research Database (Denmark)

Qin, Zhiqiang; Zhang, Jingdong; Hu, Yifan

2009-01-01

The formation of biofilms on surfaces of indwelling medical devices is a serious medical problem. Staphylococcus epidermidis is a common pathogen found to colonize implanted devices and as a biofilm is more resistant to the host immune system as well as to antibiotic treatments. Combating S....... epidermidis infections by preventing or eradicating biofilm formation of the bacterium is therefore a medically important challenge. We report here a study of biofilm formation of S. epidermidis on solid surfaces using a combination of confocal laser scanning (CLSM) and atomic force microscopy (AFM) in both...... air and aqueous environments. We have investigated the inhibitory effects of surfaces treated with four organic compounds, two benzoate derivatives denoted as compound 59 and 75 and two carboxamicle derivatives denoted as compound 47 and 73, on S. epidermidis adhesion and biofilm formation. All four...

Structural basis of small-molecule inhibition of human multidrug transporter ABCG2

DEFF Research Database (Denmark)

Jackson, Scott M; Manolaridis, Ioannis; Kowal, Julia

2018-01-01

requires high-resolution structural insight. Here, we present cryo-EM structures of human ABCG2 bound to synthetic derivatives of the fumitremorgin C-related inhibitor Ko143 or the multidrug resistance modulator tariquidar. Both compounds are bound to the central, inward-facing cavity of ABCG2, blocking...

Toxicity of Xanthene Food Dyes by Inhibition of Human Drug-Metabolizing Enzymes in a Noncompetitive Manner

International Nuclear Information System (INIS)

Mizutani, T.

2010-01-01

The synthetic food dyes studied were rose bengal (RB), phroxine (PL), amaranth, erythrosine B (ET), allura red, new coccine, acid red (AR), tartrazine, sunset yellow FCF, brilliant blue FCF, and indigo carmine. First, data confirmed that these dyes were not substrates for CYP2A6, UGT1A6, and UGT2B7. ET inhibited UGT1A6 (glucuronidation of p-nitrophenol) and UGT2B7 (glucuronidation of androsterone). We showed the inhibitory effect of xanthene dye on human UGT1A6 activity. Basic ET, PL, and RB in those food dyes strongly inhibited UGT1A6 activity, with IC50 values = 0.05, 0.04, and 0.015 mM, respectively. Meanwhile, AR of an acidic xanthene food dye showed no inhibition. Next, we studied the inhibition of CYP3A4 of a major phase I drug-metabolizing enzyme and P-glycoprotein of a major transporter by synthetic food dyes. Human CYP3A4 and P-glycoprotein were also inhibited by basic xanthene food dyes. The IC50 values of these dyes to inhibit CYP3A4 and P-glycoprotein were the same as the inhibition level of UGT1A6 by three halogenated xanthene food dyes (ET, PL, and RB) described above, except AR, like the results with UGT1A6 and UGT2B7. We also confirmed the non inhibition of CYP3A4 and P-gp by other synthetic food dyes. Part of this inhibition depended upon the reaction of O 12 originating on xanthene dyes by light irradiation, because inhibition was prevented by O 12 quenchers. We studied the influence of superoxide dismutase and catalase on this inhibition by dyes and we found prevention of inhibition by superoxide dismutase but not catalase. This result suggests that superoxide anions, originating on dyes by light irradiation, must attack drug-metabolizing enzymes. It is possible that red cosmetics containing phloxine, erythrosine, or rose bengal react with proteins on skin under lighting and may lead to rough skin.