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Glutathione Concentration (glutathione + concentration)
Selected AbstractsResveratrol modulates apoptosis and oxidation in human blood mononuclear cellsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 9 2003G. A. Losa Abstract Background, We examined the effect of resveratrol (RS), a nonflavonoid polyphenolic phytoalexin found in grapes and red wine, and RS coincubated with the oxidant 2-deoxy-D-ribose (dR), on apoptosis and on the oxidative metabolic status of normal human peripheral blood mononuclear cells (PBMNCs) isolated ex vivo from healthy donors. Material and methods, Apoptosis was measured by changes of membrane permeability to propidium iodide (PI), plasma membrane exposure of phosphatidylserine (PS) and intracellular caspase activity. Oxidative status was assessed by recording the intracellular glutathione concentration (GSH), the activities of the enzymes y -glutamyltransferase (y- GT) and glutathione-S-transferase (GST), and intracellular lipid peroxidation (MDA). Results, Neither apoptotic nor oxidative parameters were affected by culturing PBMNCs in medium containing RS up to 20 µM for 5 days, while the frequency of cells with intermediate permeability to PI (17% ± 5) increased at 50 µM of RS. Thus resveratrol was slightly toxic, but there was little apoptosis in these cells. Peripheral blood mononuclear cells were also grown first in medium plus RS for 24 h and then for 96 h in medium containing RS plus 10 mM of dR, an oxidant sugar that is apoptogenic for human lymphocytes. The apoptotic changes triggered by dR were counteracted by the phytoalexin in a dose-dependent manner, but RS activity was absent at the lowest concentration (5 µM) and significantly reduced at the highest concentration used (50 µM). In PBMNCs coincubated with 20 µM of RS and 10 mM of dR the antioxidant effect of RS manifested with a significant reduction of caspases-3, -8, y- GT, GST activities and MDA content. Conclusions, Peripheral blood mononuclear cells acquire antioxidant capacity when treated with RS. Grape resveratrol may make a useful dietary supplement for minimizing oxidative injury in immune-perturbed states and human chronic degenerative diseases. [source] Expression and regulation of L-cystine transporter, system xc,, in the newly developed rat retinal Müller cell line (TR-MUL)GLIA, Issue 3 2003Masatoshi Tomi Abstract The purpose of the present study was to elucidate the expression and regulation of the L-cystine transporter, system xc,, in Müller cells. In this study, newly developed conditionally immortalized rat Müller cell lines (TR-MUL) from transgenic rats harboring the temperature-sensitive SV 40 large T-antigen gene were used as an in vitro model. TR-MUL cells express large T-antigen and grow well at 33°C with a doubling time of 30 h, but do not grow at 39°C. TR-MUL cells express typical Müller cell markers such as S-100, glutamine synthetase, and EAAT1/GLAST, whereas EAAT2/GLT-1 and EAAT5 are not detected. TR-MUL cells also exhibit little or no expression of glial fibrillary acidic protein. We found that TR-MUL5 cells exhibited [14C]L-cystine uptake activity and expressed xCT and 4F2hc, which involve system xc,. The uptake of [14C]L-cystine was significantly inhibited by L-glutamic acid and L-aspartic acid, whereas L-leucine had no effect. Following diethyl maleate (DEM) treatment, the glutathione concentration in TR-MUL5 cells was reduced in the first 24 h, then gradually recovered for more than 24 h. The L-cystine uptake rate and the xCT expression level in TR-MUL5 cells were enhanced by DEM treatment. In contrast, the 4F2hc expression level was unchanged. In conclusion, TR-MUL cells have the properties of Müller cells and exhibit system xc, -mediated L-cystine uptake activity. The oxidative stress conditions following DEM treatment activate L-cystine transport in TR-MUL cells due to the enhanced transcription of the xCT gene. GLIA 9999:000,000, 2003. © 2003 Wiley-Liss, Inc. [source] Effects of quercetin on antioxidant defense in streptozotocin-induced diabetic ratsJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 3 2001Ruth A. Sanders Abstract In light of evidence that some complications of diabetes mellitus may be caused or exacerbated by oxidative damage, we investigated the effects of subacute treatment with the antioxidant quercetin on tissue antioxidant defense systems in streptozotocin-induced diabetic Sprague-Dawley rats (30 days after streptozotocin induction). Quercetin, 2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-1-benzopyran-4-one, was administered at a dose of 10mg/kg/day, ip for 14 days, after which liver, kidney, brain, and heart were assayed for degree of lipid peroxidation, reduced and oxidized glutathione content, and activities of the free-radical detoxifying enzymes catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase. Treatment of normal rats with quercetin increased serum AST and increased hepatic concentration of oxidized glutathione. All tissues from diabetic animals exhibited disturbances in antioxidant defense when compared with normal controls. Quercetin treatment of diabetic rats reversed only the diabetic effects on brain oxidized glutathione concentration and on hepatic glutathione peroxidase activity. By contrast, a 20% increase in hepatic lipid peroxidation, a 40% decline in hepatic glutathione concentration, an increase in renal (23%) and cardiac (40%) glutathione peroxidase activities, and a 65% increase in cardiac catalase activity reflect intensified diabetic effects after treatment with quercetin. These results call into question the ability of therapy with the antioxidant quercetin to reverse diabetic oxidative stress in an overall sense. © 2001 John Wiley & Sons, Inc. J Biochem Mol Toxicol 15:143,149, 2001 [source] Use of L -[15N] glutamic acid and homoglutathione to determine both glutathione synthesis and concentration by gas chromatography-mass spectrometry (GCMS)JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 7 2001Bernard Humbert Abstract A method for simultaneous measurement of both glutathione enrichment and concentration in a biological sample using gas chromatography mass spectrometry is described. The method is based on the preparation of N,S -ethoxycarbonylmethyl ester derivatives of glutathione, and the use of homoglutathione (glutamyl,cysteinyl,alanine) as an internal standard. A procedure for determination of glutamate concentration and enrichment is also reported. Both methods have within-day and day-to-day inter-assay coefficients of variation less than 5%, and recoveries of known added amounts of glutathione and glutamate are close to 100%. Taken together, these methods allowed determination of glutathione concentration and fractional synthesis rate in red blood cells using L -[15N] glutamic acid infusion. This approach was applied in vivo to investigate the effects of a 72 h fast, compared with a control overnight fast, on erythrocyte glutathione in a single dog. The 72 h fast was associated with a 39% decline in erythrocyte glutathione level, (2.9 ± 0.4 versus 4.7 ± 0.5 mmol l,1, fasting versus control) with no change in glutathione fractional synthesis (67.4 versus 71.3% d,1, fasting versus control). Copyright © 2001 John Wiley & Sons, Ltd. [source] The effect of unfiltered coffee on potential biomarkers for colonic cancer risk in healthy volunteers: a randomized trialALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 9 2000Grubben Background: Epidemiologic studies suggest that coffee use might protect against colorectal cancer. Inconsistencies as to the effect of coffee use and colorectal cancer between epidemiologic studies might be related to the type of coffee brew. Objective: We studied the effect of unfiltered coffee consumption on putative biomarkers for colonic cancer risk. Design: A total of 64 healthy volunteers (31 men and 33 women), with a mean age of 43 ± 11 years were randomly assigned to two groups in a crossover design, with two intervention periods of 2 weeks separated by a washout period of 8 weeks. Treatments were 1 L of cafetičre (French press) coffee daily or no coffee. At the end of each intervention period, fasting blood samples, colorectal biopsies and 48 h faeces were collected. Results: No effect of coffee on colorectal cell proliferation, assayed by estimating the Proliferating Cell Nuclear Antigen labelling index, was seen. Additionally, no effects were seen on the concentrations of faecal soluble bile acids and colorectal mucosal glutathione S-transferase activity. However, unfiltered coffee significantly increased the glutathione content in the colorectal mucosa by 8% and in plasma by 15%. Other aminothiols in plasma also increased on coffee. Conclusion: Unfiltered coffee does not influence the colorectal mucosal proliferation rate, but might increase the detoxification capacity and anti-mutagenic properties in the colorectal mucosa through an increase in glutathione concentration. Whether this effect indeed contributes to a lower colon cancer risk remains to be established. [source] Influence of glutamine and vitamin E on growth and antioxidant capacity of fish enterocytesAQUACULTURE NUTRITION, Issue 4 2009J. JIANG Abstract The present study explored the effect of glutamine and vitamin E on growth and anti-oxidation capacity of isolated fish enterocytes. Fish enterocytes were cultured with six medium, respectively, containing 0, 2.0, 4.7, 6.8, 8.1, 9.2 mmol L,1 glutamine for 64 h. The results showed that glutamine could promote fish enterocytes proliferation and differentiation. Fish enterocytes were cultured with different medium containing 0, 2.5, 3.5, 4.5, 6.0, 7.0 ,g mL,1 vitamin E for 96 h. The results showed that cells proliferation and differentiation were not significantly enhanced, but anti-superoxide anion activity, anti-hydroxy radical activity, reduced glutathione concentration, the ratio between reduced and total glutathione in the cells were significantly enhanced, and the malondialdehyde concentration in the culture medium was significantly depressed with the vitamin E treatment. In the whole, the present results firstly indicated that glutamine could promote fish enterocytes growth, but vitamin E could not. Vitamin E could promote fish enterocytes antioxidant capacity and cellular structural integrity. These data would be instructive for glutamine and vitamin E supplement in aquaculture diets. [source] The Effect of Glutathione Modulation on the Concentration of Homocysteine in Plasma of RatsBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 3 2000Kjell K. Ųvrebų Elevated plasma homocysteine concentration in humans is associated with increased risk of arteriosclerosis and ischaemic heart disease. We studied whether the plasma homocysteine concentration could be changed by administration of drugs that modulate the concentration of glutathione in both plasma and tissue. Male wistar rats received reduced glutathione (0.5 mmol/kg), N -acetylcysteine (0.5 mmol/kg), L-buthionine-[S,R]-sulfoximine (2 mmol/kg) or Ringer acetate intravenously. Twenty min. later an arterial blood sample was drawn for the measurement of homocysteine and other thiols in the plasma. The thiols were quantified by reversed-phase ion-pair liquid chromatography and fluorescence detection. The total homocysteine concentration in plasma of fasted rats was 6.1±0.5 ,M. Intravenous administration of reduced glutathione or N -acetylcysteine reduced the homocysteine concentration in plasma significantly by 51% to 3.0±0.3 ,M and 63% to 2.2±0.2 ,M, respectively (P<0.05). In contrast, L-buthionine-[S,R]-sulfoximine increased the concentration of homocysteine by 41% to 8.6±0.6 ,M (P<0.05). The glutathione concentration in plasma was 19.5±1.9 ,M in controls and was unchanged by N -acetylcysteine administration. Reduced glutathione increased plasma glutathione to 379.7±22.9 ,M (P<0.05), whereas L-buthionine-[S R]-sulfoximine lowered the plasma glutathione concentration to 5.3±0.4 ,M. Homocysteine was negatively correlated to the glutathione (r=,0.399, P<0.01) and the cysteine (r=,0.52, P<0.01) concentrations in plasma. Our conclusion is that modulation of the glutathione levels influences the concentration of homocysteine in plasma of rats. [source] Protective Effect of Ebselen on Aflatoxin B1 -Induced Cytotoxicity in Primary Rat HepatocytesBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 4 2000Cheng-Feng Yang Recent studies have shown that aflatoxin B1 enhances reactive oxygen species formation and causes oxidative damage, which may ultimately contribute to the cytotoxicity and carcinogenic effect of aflatoxin B1. Ebselen, 2-phenyl-1,2-benzoisoseleazol-3(H)-one, a synthetic seleno-organic compound has been shown to possess glutathione peroxidase-like activity and free radical scavenging ability. Thus present study was designed to investigate the protective effect of ebselen on aflatoxin B1 -induced cytotoxicity in primary rat hepatocytes. Aflatoxin B1 -induced cytotoxicity and lipid peroxidation were determined by lactate dehydrogenase leakage and malondialdehyde generation, respectively. Intracellular reactive oxygen species level was measured using the fluorescent probe 2,,7,-dichlorofluorescin diacetate, and the intracellular reduced glutathione concentration was determined with a fluorometric method. Ebselen was found to display a dose-dependent protective effect on lactate dehydrogenase leakage and malondialdehyde generation caused by aflatoxin B1 exposure. The results also demonstrate that ebselen efficiently inhibits the intracellular reactive oxygen species formation in aflatoxin B1 -treated hepatocytes in a dose and time-dependent manner. It was also noted that ebselen was able to increase the intracellular reduced glutathione concentration, both in the control and in aflatoxin B1 -treated hepatocytes. The protection of ebselen against aflatoxin B1 cytotoxicity, however, was not affected by lowering the concentration of intracellular reduced glutathione. The overall data indicate that ebselen possesses a potent protective effect against aflatoxin B1 -induced cytotoxicity, and the main mechanism involved in the protection may be its strong capability in inhibiting intracellular reactive oxygen species formation and preventing oxidative damage. [source] Antioxidant capacity of human milk: effect of thermal conditions for the pasteurizationACTA PAEDIATRICA, Issue 8 2008Dolores Silvestre Abstract Aim: Pasteurization is the thermal treatment usually applied in milk banks to eliminate the risk of transmission of infectious agents. The aim of this study was to investigate the effect of heat processing upon the antioxidant properties of human milk. Methods: Milk samples collected from 31 healthy women were subjected to two different pasteurization techniques: Holder pasteurization (63°C for 30 min) and high pasteurization (75°C for 15 sec) and oxidative stress markers (glutathione, glutathione peroxidase activity, malondialdehyde and total antioxidant capacity) were determined in comparison to fresh milk. Results: Malondialdehyde concentration was the same in all samples, while there was a decrease in glutathione concentration and total antioxidant capacity in milk samples subjected to thermal processing versus fresh milk samples. However, the drop in these parameters was seen to be significantly greater when applying Holder pasteurization. Both thermal treatments induced considerable and similar loss of glutathione peroxidase activity. Conclusion: Thermal processing of human milk implies a decrease in its antioxidant properties but, when necessary, high pasteurization should be the election method in terms of milk oxidative status. [source] Drug design: hiding in full viewDRUG DEVELOPMENT RESEARCH, Issue 1 2008Norman S. Radin Abstract Compounds that can produce potent biological effects in cells encompass a variety of structural motifs. Many of these compounds share a structural feature that has rarely been noted. It is an allylic cluster of atoms, a 3-carbon chain with a double bond between two of the atoms and an oxygen atom at the other end. The oxygen can be in a hydroxyl group, or in an ether or ketal or ester linkage, or simply a carbonyl form. In the latter case, the linkage is an allylic ketone (ene-one) structure. Nitrogen is often seen in equivalent forms. Inclusion of at least one allylic moiety appears to be able to turn a modestly active or inert compound into an effective drug or toxin. Some compounds lack the allylic moiety but develop one by enzymatic action, usually via cytochrome P-450 enzymes. These metabolites probably represent the active drug forms. The above concepts seem to be radically simplistic and improbable, but the evidence supporting them and the explanations for the biological activities are hidden "in plain view." Comparisons with the pleiotropic activities of the allylic sphingolipid, ceramide, indicate that many allylic drugs operate by controlling the state of protein phosphorylation, by activating proteases, by generating reactive oxygen species, by slowing mitochondrial electron transport, or by lowering cellular glutathione concentrations. Drug Dev Res 69:15,25, 2008 © 2008 Wiley-Liss, Inc. [source] Microglial glutamate uptake is coupled to glutathione synthesis and glutamate releaseEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2006Mikael Persson Abstract The physiological function of microglial glutamate uptake has been debated as it is about 10% of that measured for astrocytes. This study addresses how glutamate, taken up from the extracellular space, is utilized by microglia. It was found that purified rat microglia incubated for 60 min with 3H-glutamate had an increased intracellular accumulation of 3H-glutamate after 12 h incubation with tumour necrosis factor alpha (TNF-,) but not after incubation with lipopolysaccharide (LPS). Furthermore, LPS- but not TNF-,-treated cells showed an increased efflux of 3H-labelled compounds, presumably glutamate through the XC, system and treatment with LPS or TNF-, increased the microglial glutathione concentrations and led to an increased incorporation of 3H-glutamate into glutathione. Depending on the stimuli, 3,6% of the total labelled contents were found in the form of glutathione and 25,35% in the form of glutamate. These results show that microglial glutamate uptake is directly coupled to glutathione synthesis and release of glutamate and/or glutamate metabolites. Additionally, the increased glutathione contents after LPS or TNF-, treatment were able to reduce microglial cell death after H2O2 challenge, showing a potential (self)-protective function for microglial glutamate transporter expression and glutathione synthesis. [source] Effects of smoking and gingival inflammation on salivary antioxidant capacityJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 3 2006Nurcan Buduneli Abstract Aim: This study evaluated possible effects of smoking and gingival inflammation on salivary antioxidants in gingivitis patients. Methods: Twenty otherwise healthy gingivitis patients (10 self-reported smokers) and 20 periodontally and systemically healthy volunteer subjects were enrolled in the study. Whole saliva samples and full-mouth clinical periodontal recordings were obtained at baseline and one month following initial phase of treatment in gingivitis patients. Salivary cotinine, glutathione and ascorbic acid concentrations, and total antioxidant capacity were determined, and the data generated were tested by non-parametric tests. Results: Salivary cotinine measurements resulted in re-classification of three self-reported non-smokers as smokers. Smoker patients revealed significantly higher probing depths but lower bleeding values than non-smoker patients (p=0.044 and 0.001, respectively). Significant reductions in clinical recordings were obtained in non-smoker (all p<0.05) and smoker (all p<0.01) patients following periodontal treatment. Salivary total glutathione concentrations were reduced following therapy in gingivitis patients who smoke (p<0.01). Otherwise, no statistically significant differences were found between the groups in biochemical parameters at baseline or following treatment (p>0.05). Conclusions: Within the limits of this study, neither smoking nor gingival inflammation compromised the antioxidant capacity of saliva in systemically healthy gingivitis patients. [source] Effects of Chronic Alcohol Abuse on Alveolar Epithelial Barrier Function and Glutathione HomeostasisALCOHOLISM, Issue 7 2003Ellen L. Burnham Background: An association between the development and severity of the acute respiratory distress syndrome has been described in individuals who abuse alcohol chronically, possibly through a mechanism involving the deficiency of pulmonary glutathione. In a rodent model of chronic alcohol abuse, this antioxidant contributes to the maintenance of alveolar-capillary membrane integrity. We postulated that humans who chronically abuse alcohol will have similar alterations in alveolar-capillary barrier function. Methods: Bronchoalveolar lavage was performed in 18 healthy chronic alcoholics and 18 control subjects; total protein and glutathione concentrations were measured within the epithelial lining fluid. To examine possible protracted effects of alcohol abuse, a subset of 11 chronic alcoholic subjects underwent a second bronchoalveolar lavage after a week of abstinence. Results: Chronic alcoholic subjects had significantly elevated protein concentrations compared with controls (8.64 ,g protein/ng immunoglobulin A vs. 5.91 ,g protein/ng immunoglobulin A, p= 0.01). After a week of abstinence, no significant increase in either the glutathione levels or normalization of the protein concentrations in the epithelial lining fluid was demonstrable. Conclusions: Increased protein levels in the epithelial lining fluid of individuals who abuse alcohol chronically may signify abnormal alveolar epithelial barrier function that does not appear to readily reverse after a period of abstinence. [source] Early phase of reperfusion of human kidney allograft does not affect an erythrocyte anti-oxidative systemNEPHROLOGY, Issue 5 2006LESZEK DOMA SUMMARY: Background: Generation of reactive oxygen specimens is the basic mechanism leading to ischaemia/reperfusion injury of the kidney graft. Oxygen burst is a trigger for sophisticated biochemical changes leading to generation of oxygenated lipids and changes in microcirculation, which recruit recipient's neutrophils and contribute to delayed graft function. It has been shown that the free radicals generation correlates with the activity of anti-oxidative system. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione (GSH) are involved in protection against free radicals. Aim: To examine the activity of erythrocyte anti-oxidative system during reperfusion of the transplanted kidney allograft. Methods: The study included 40 renal transplant recipients. Blood was taken from the iliac vein before transplantation and from the graft's renal vein immediately, as well as 2 and 4 min after total reperfusion. The authors assessed the process of reperfusion using ThermaCAM SC500 termovision camera. Spectrophotometric methods were used to measure superoxide dismutase, glutathione peroxidase and catalase activity as well as glutathione concentrations in erythrocytes. Results: There were no statistically significant differences in the activities of superoxide dismutase, catalase and glutathione peroxidase as well as glutathione concentrations during the first 4 min after total graft reperfusion. Nevertheless, there was a positive correlation between the activity of superoxide dismutase and glutathione peroxidase. Conclusion: The results suggest that the erythrocyte anti-oxidative system is stable during the early phase after reperfusion. An association between some anti-oxidative enzymes was noted. [source] | ||||||||||||||||