Glutathione Status Research Articles

A 6-week training program increased muscle antioxidant system in elderly diabetic fatty rats

SummaryBackgroundIt is widely accepted that oxidative stress is associated with the physiopathology of type 2 diabetes mellitus. In fact, it has been pointed out as a therapeutic target in T2DM. Fortunately, several papers have reported that long-term training programs improved the antioxidant system in young and adult diabetic rats. Accordingly, this study was designed to assess the influence of a shorter training program in elderly diabetic fatty rats.Material/MethodsStudy subjects were 24 male homozygous Zucker diabetic fatty rats (Gmi, fa/fa) aged 18 weeks with an average weight of 370–450 g. After a 2-week period of environmental adaptation, animals were randomly distributed into the Exercised Group (n=12) that performed a 6-week swimming training protocol and the Sedentary Group (n=12). Animals were sacrificed under anesthesia 24 h after the last exercise session. Serum metabolic profile was determined. Total antioxidant status (TAS), MnSOD expression, glutathione status and ROS generation were assayed in gastrocnemius muscle.ResultsWhen compared with controls, exercised rats significantly improved their metabolic profile. Total antioxidant status (0.19±0.002 vs. 0.13±0.002 μg/mg protein; p<0.001) and MnSOD expression (8471±90 vs. 6258±102 U/μg protein; p=0.003) were also increased in exercised rats.ConclusionsA 6-week swimming training program improved the antioxidant system in elderly fatty diabetic rats. Fortunately, this improvement was enough to reduce oxidative damage, expressed as protein oxidation. A major finding of this study was that our training protocol lasted just 6 weeks, in contrast to longer protocols previously published.

Restoration of Brain Antioxidant Status by Hydroalcoholic Extract of Mimusops elengi Flowers in Rats Treated With Monosodium Glutamate

Monosodium glutamate (MSG) is commonly used as a flavor enhancer in many countries. However, overconsumption of MSG has been reported to produce detrimental effects on several organs. It mainly affects the normal physiology and function of the brain and causes severe oxidative stress. Mimusops elengi Linn. traditionally is used in many countries as a brain tonic and to calm anxiety and panic attacks. The effect of standardized hydroalcoholic extract of M. elengi flowers (ME) was evaluated against MSG-induced oxidative stress and excitotoxicity in Wistar rats. Excitotoxicity was induced by intraperitoneal administration of MSG (2 g/kg) for 7 days, and ME (100 and 200 mg/kg) was administered for 3 days before and for 7 days with administration of MSG. Animals were evaluated for locomotor activity, and brain homogenates were estimated for the levels of antioxidants and nitrite. In animals treated with MSG, pretreatment with ME improved ambulatory behavior, reduced lipid peroxidation and nitrite levels, and restored the enzymatic and nonenzymatic antioxidant (glutathione, total thiols, glutathione-S-transferase and catalase) status to near-normal levels; these were altered in the MSG control animals. Altogether, this investigation demonstrates the neuroprotective effect of ME against excitotoxicity and oxidative stress induced by MSG, and the observed protective effect might be attributed to the potential antioxidant property of ME.

Oxidative stress adaptation in aggressive prostate cancer may be counteracted by the reduction of glutathione reductase

Oxidative stress has been associated with prostate cancer development and progression due to an increase of reactive oxygen species (ROS). However, the mechanisms whereby ROS and the antioxidant system participate in cancer progression remain unclear.In order to clarify the influence of oxidative stress in prostate cancer progression, we performed this study in two human prostate cancer cell lines, PC3 and HPV10 (from metastasis and from localized cancer, respectively) and RWPE1 cells derived from normal prostate epithelium. Cells were treated with hydrogen peroxide (H2O2) and PC3 cells were also treated with diethyl maleate (DEM). The effect on cell growth, viability, mitochondria membrane potential and oxidative stress was analysed. Oxidative stress was evaluated based on ROS production, oxidative lesion of lipids (MDA) and on determination of antioxidants, including enzyme activity of glutathione peroxidase (Gl-Px), glutathione reductase (Gl-Red) and on the quantification of glutathione (GSH), glutathione-s-transferase (GST) and total antioxidant status (TAS).PC3 shows higher ROS production but also the highest GSH levels and Gl-Red activity, possibly contributing to oxidative stress resistance. This is also associated with higher mitochondrial membrane potential, TAS and lower lipid peroxidation. On the other hand, we identified Gl-Red activity reduction as a new strategy in overcoming oxidative stress resistance, by inducing H2O2 cytotoxicity. Therefore these results suggest Gl-Red activity reduction as a new potential therapeutic approach, in prostate cancer.

Plasma zinc antioxidant vitamins, glutathione levels and total antioxidant activity in oral leukoplakia

Leukoplakia is a common, potentially premalignant lesion with malignant transformation rate from 1 to 17% with highest transformation rate for the lesions on the floor of the mouth, soft palate and tongue. One of the main etiological factors is consuming areca nut and its commercial preparations which generate high levels of reactive oxygen species during their metabolism. So the aim of this present study is to evaluate the plasma levels of antioxidant vitamins, antioxidant mineral zinc, glutathione and total antioxidant status (TAS) in leukoplakia patients. For this cross-sectional study, we selected 23 newly diagnosed oral leukoplakia patients of both sexes within the age group 28-40 years and the same number of age and sex matched healthy individuals without having history of any systemic illness were selected as control group. In both the groups, we measured plasma antioxidant vitamins A, C, E, antioxidant mineral zinc, GSH and TAS. Student's t test was applied and the P value <0.001 was considered as statistically significant. We observed very low levels of antioxidant vitamins A, C, E, antioxidant mineral zinc and antioxidant metabolite GSH (P<0.001) and at the same time we also observed very poor (TAS) (P<0.001) in leukoplakia patients when compared to patients in control group. The consumption of tobacco or areca quid which contains high copper levels creates an oxidative stress like environment during their metabolism, might play a major role in causation and propagation of oral leukoplakia.

Oxidative stress, glutathione status, sirtuin and cellular stress response in type 2 diabetes

Oxidative stress has been suggested to play a main role in the pathogenesis of type 2 diabetes mellitus and its complications. As a consequence of this increased oxidative status a cellular adaptive response occurs requiring functional chaperones, antioxidant production and protein degradation. This study was designed to evaluate systemic oxidative stress and cellular stress response in patients suffering from type 2 diabetes and in age-matched healthy subjects. Systemic oxidative stress has been evaluated by measuring plasma reduced and oxidized glutathione, as well as pentosidine, protein carbonyls lipid oxidation products 4-hydroxy-2-nonenal and F2-isoprostanes in plasma, and lymphocytes, whereas the lymphocyte levels of the heat shock proteins (HSP) HO-1, Hsp72, Sirtuin-1, Sirtuin-2 and thioredoxin reductase-1 (TrxR-1) have been measured to evaluate the systemic cellular stress response. Plasma GSH/GSSG showed a significant decrease in type 2 diabetes as compared to control group, associated with increased pentosidine, F2-isoprostanes, carbonyls and HNE levels. In addition, lymphocyte levels of HO-1, Hsp70, Trx and TrxR-1 (P<0.05 and P<0.01) in diabetic patients were higher than in normal subjects, while sirtuin-1 and sirtuin-2 protein was significantly decreased (p<0.05). In conclusion, patients affected by type 2 diabetes are under condition of systemic oxidative stress and, although the relevance of downregulation in sirtuin signal has to be fully understood, however induction of HSPs and thioredoxin protein system represent a maintained response in counteracting systemic pro-oxidant status. This article is part of a Special Issue entitled: Antioxidants and Antioxidant Treatment in Disease.

Abstract C180: The effect of JS-K, a lead O2-arylated diazeniumdiolate anticancer agent, on the cellular glutathione status.

Abstract JS-K is an O2-arylated diazeniumdiolate prodrug which has demonstrated pronounced selective cytotoxicity and antitumorigenic properties in a variety of cancer models both in vitro and in vivo. Mass spectrometric studies of the metabolic fate of JS-K were undertaken to understand the origin of the cytotoxicity. Consistent with model chemical reactions, the first step in the cellular metabolism of JS-K is the de-arylation of the diazeniumdiolate by glutathione (GSH) via a nucleophilic aromatic substitution reaction, forming a dinitrophenyl-GSH adduct, with the daizeniumdiolate ion by-product ultimately releasing nitric oxide (NO). A consequence of this metabolism and NO-generation is a rapid and pronounced depletion of cellular GSH concurrent with a rise in oxidized glutathione (GSSG). The GSH/GSSG redox couple, considered to be the major redox buffer of the cell, helps maintain a reducing environment under basal conditions. The depletion of GSH through drug conjugation and subsequent oxidation results in a rapid rise in the oxidation potential of the cellular environment, an increase of 30 mV in the first 30 min of treatment, initiating the stress signaling pathways which lead to extrinsic/intrinsic apoptosis. Preventing this rise in the oxidation potential by pre-treating cells with known antioxidant N-acetylcysteine inhibited the downstream signaling events leading to apoptosis. These data indicate that depletion of the glutathione pool is a crucial first step in the mechanism of JS-K cytotoxicity. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C180.

Novel metabolic biomarkers related to sulfur-dependent detoxification pathways in autistic patients of Saudi Arabia.

BackgroundXenobiotics are neurotoxins that dramatically alter the health of the child. In addition, an inefficient detoxification system leads to oxidative stress, gut dysbiosis, and immune dysfunction. The consensus among physicians who treat autism with a biomedical approach is that those on the spectrum are burdened with oxidative stress and immune problems. In a trial to understand the role of detoxification in the etiology of autism, selected parameters related to sulfur-dependent detoxification mechanisms in plasma of autistic children from Saudi Arabia will be investigated compared to control subjects.Methods20 males autistic children aged 3-15 years and 20 age and gender matching healthy children as control group were included in this study. Levels of reduced glutathione (GSH), total (GSH+GSSG), glutathione status (GSH/GSSG), glutathione reductase (GR), glutathione- s-transferase (GST), thioredoxin (Trx), thioredoxin reductase (TrxR) and peroxidoxins (Prxs I and III) were determined.ResultsReduced glutathione, total glutathione, GSH/GSSG and activity levels of GST were significantly lower, GR shows non-significant differences, while, Trx, TrxR and both Prx I and III recorded a remarkably higher values in autistics compared to control subjects.ConclusionThe impaired glutathione status together with the elevated Trx and TrxR and the remarkable over expression of both Prx I and Prx III, could be used as diagnostic biomarkers of autism.

Salicylic acid-induced glutathione status in tomato crop and resistance to root-knot nematode, Meloidogyne incognita (Kofoid &amp; White) Chitwood

Salicylic acid-(SA) is a plant defense stimulator. Exogenous application of SA might influence the status of glutathione-(GSH). GSH activates and SA alters the expression of defense genes to modulate plant resistance against pathogens. The fate of GSH in a crop following SA treatment is largely unknown. The SA-induced profiles of free reduced-, free oxidized-(GSSG) and protein bound-(PSSG) glutathione in tomato crop following foliar treatment of transplant at 5.0-10.0 &amp;mu;g mL&amp;ndash;1 were measured by liquid chromatography. Resistance to root-knot nematode, &lt;em&gt;Meloidogyne incognita&lt;/em&gt; damaging tomato and crop performance were also evaluated. SA treatment at 5.0-10.0 &amp;mu;g mL&amp;ndash;1 to tomato transplants increased GSH, GSSG and PSSG in plant leaf and root, more so in leaf, during crop growth and development. As the fruits ripened, GSH and PSSG increased and GSSG declined. SA reduced the root infection by &lt;em&gt;M. incognita&lt;/em&gt;, nematode reproduction and thus, improved the resistance of tomato var. Pusa Ruby, but reduced crop growth and redox status. SA at 5.0 &amp;mu;g mL&amp;ndash;1 improved yield and fruit quality. The study firstly linked SA with activation of glutathione metabolism and provided an additional dimension to the mechanism of induced resistance against obligate nematode pathogen. SA increased glutathione status in tomato crop, imparted resistance against &lt;em&gt;M. incognita&lt;/em&gt;, augmented crop yield and functional food quality. SA can be applied at 5.0 &amp;mu;g mL&amp;ndash;1 for metabolic engineering of tomato at transplanting to combine host-plant resistance and health benefits in formulating a strategic nematode management decision.

Effects of Oral Glutathione Supplementation on Systemic Oxidative Stress Biomarkers in Human Volunteers

The tripeptide glutathione (GSH) is the most abundant free radical scavenger synthesized endogenously in humans. Increasing mechanistic, clinical, and epidemiological evidence demonstrates that GSH status is significant in acute and chronic diseases. Despite ease of delivery, little controlled clinical research data exist evaluating the effects of oral GSH supplementation. The study objectives were to determine the effect of oral GSH supplementation on biomarkers of systemic oxidative stress in human volunteers. This was a randomized, double-blind, placebo-controlled clinical trial. The study was conducted at Bastyr University Research Institute, Kenmore, WA and the Bastyr Center for Natural Health, Seattle, WA. Forty (40) adult volunteers without acute or chronic disease participated in this study. Oral GSH supplementation (500 mg twice daily) was given to the volunteers for 4 weeks. Primary outcome measures included change in creatinine-standardized, urinary F2-isoprostanes (F2-isoP) and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG). Changes in erythrocyte GSH concentrations, including total reduced glutathione (GSH), oxidized glutathione (GSSG), and their ratio (GSH:GSSG) were also measured by tandem liquid chromatography/mass spectrometry. Analysis of variance was used to evaluate differences between groups. There were no differences in oxidative stress biomarkers between treatment groups at baseline. Thirty-nine (39) participants completed the study per protocol. Changes in creatinine standardized F2-isoP (ng/mg creatinine) (0.0±0.1 versus 0.0±0.1, p=0.38) and 8-OHdG (μg/g creatinine) (-0.2±3.3 versus 1.0±3.2, p=0.27) were nonsignificant between groups at week 4. Total reduced, oxidized, and ratio measures of GSH status were also unchanged. No significant changes were observed in biomarkers of oxidative stress, including glutathione status, in this clinical trial of oral glutathione supplementation in healthy adults.

Glutathione in plants: an integrated overview

Plants cannot survive without glutathione (γ-glutamylcysteinylglycine) or γ-glutamylcysteine-containing homologues. The reasons why this small molecule is indispensable are not fully understood, but it can be inferred that glutathione has functions in plant development that cannot be performed by other thiols or antioxidants. The known functions of glutathione include roles in biosynthetic pathways, detoxification, antioxidant biochemistry and redox homeostasis. Glutathione can interact in multiple ways with proteins through thiol-disulphide exchange and related processes. Its strategic position between oxidants such as reactive oxygen species and cellular reductants makes the glutathione system perfectly configured for signalling functions. Recent years have witnessed considerable progress in understanding glutathione synthesis, degradation and transport, particularly in relation to cellular redox homeostasis and related signalling under optimal and stress conditions. Here we outline the key recent advances and discuss how alterations in glutathione status, such as those observed during stress, may participate in signal transduction cascades. The discussion highlights some of the issues surrounding the regulation of glutathione contents, the control of glutathione redox potential, and how the functions of glutathione and other thiols are integrated to fine-tune photorespiratory and respiratory metabolism and to modulate phytohormone signalling pathways through appropriate modification of sensitive protein cysteine residues.

Effect of andrographolide on cysteamine-induced duodenal ulcer in rats

The aim of this study was to evaluate the gastroprotective efficacy of andrographolide isolated from Andrographis paniculata in rats induced with duodenal ulcers. Duodenal ulcers were induced by cysteamine administration in rats pretreated with 3 mg kg−1 BW day−1 of andrographolide for 30 days. Ulcer score, myeloperoxidase activity, TBARS level, GSH/GSSG ratio and enzyme antioxidants were measured in the duodenal tissue. Brush border and basolateral membranes were isolated to assay sucrase, maltase, alkaline phosphatase and total ATPases. Ulcer score was significantly minimised in rats pretreated with andrographolide. Elevation in myeloperoxidase and TBARS levels were found to be minimised significantly due to andrographolide treatment. Membrane-bound enzyme activities and the thiol redox status of glutathione were significantly maintained in duodenal mucosa of rats that received andrographolide. This study reveals that the major component of A. paniculata, andrographolide, has potent antiulcer properties that are most likely caused by minimising inflammatory changes, counteracting free radical formation and maintaining the thiol redox status in the duodenum.

Responses to drought stress of the biosynthetic and recycling metabolism of glutathione and ascorbate in &lt;I&gt;Agropyron cristatum&lt;/I&gt; leaves on the Loess Plateau of China

Aims Our objective was to clarify the mechanism of drought tolerance for Agropyron cristatum on the Loess Plateau of China through investigation of drought stress on the biosynthetic and recycling metabolism of glutathione and ascorbate in leaves. Methods We investigated the levels and redox status of glutathione and ascorbate and the activities of galactonolactone dehydrogenase (GalLDH), gamma glutamyl cysteine synthetase (γ-ECS), ascorbate peroxidase glutathione reductase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDHAR) in the leaves of A. cristatum under different levels of artificial drought stress using pot experiments. Important findings Levels of glutathione and ascorbate and their redox status were maintained under drought stress by increasing activities of GalLDH, γ-ECS, APX, GR, DHAR and MDHAR involved in the metabolism of glutathione and ascorbate. This protected A. cristatum from oxidative damage induced by drought stress. However, there were differences in the responses of the metabolism of glutathione and ascorbate related to different drought stress levels with prolonged stress. With 24 or fewer days of stress treatment, the metabolism of glutathione and ascorbate was enhanced under severe drought stress. After 24 days of stress treatment, the activities of GalLDH, γ-ECS, APX, GR, DHAR and MDHAR decreased significantly under severe drought stress, because A. cristatum suffered more severe oxidative damage. However, the activities of these enzymes were maintained throughout the whole period of stress under moderate drought stress. This suggested that A. cristatum could effectively protect itself from oxidative damage induced by moderate drought stress for long time periods. However, A. cristatum could only effectively protect itself from oxidative damage induced by severe drought stress for limited time, and its antioxidant capacity decreased significantly with prolonged stress. Our results also suggested that ascorbate and glutathione had important roles in protecting against oxidative damage under drought stress.

Derivação gástrica em Y-de-Roux e a atividade inflamatória do tecido adiposo

To evaluate the oxidative stress and inflammatory markers in obese patients before and after Roux-en-Y vertical banded gastroplasty. We studied 20 class III obese patients undergoing Roux-en-Y vertical banded gastroplasty, seven men and 13 women, mean age 39 years, and 20 non-obese subjects, nine males and 11 females, mean age 38 years. We determined the plasma levels of malondialdehyde, stress an index, total antioxidant capacity, catalase, reduced and oxidized glutathione and inflammatory markers (C reactive protein and á-1 acid glycoprotein). In the obese group, these parameters were determined before and 2, 6 and 12 months after gastroplasty. Preoperatively, the obese group showed elevated levels of inflammatory markers of oxidative stress (malondialdehyde levels and stress index) and lower levels of indicators of antioxidant defense compared to the control group. Weight loss was accompanied by gradual reduction in the levels of malondialdehyde and stress index. We found an increased concentration of reduced glutathione and total antioxidant status and reduced levels of inflammatory markers. Weight loss improves the inflammatory state and oxidative stress levels.

Effect of diets with different inclusion levels of distillers dried grain with solubles combined with lysine and methionine supplementation on the lipid peroxidation and glutathione status of chickens

To study the possible effects of different inclusion levels of distillers dried grain with solubles (DDGS) on the lipid peroxidation and glutathione redox status of chickens, 200 three-week-old Ross 308 cockerels were assigned to four treatment groups of 50 birds each. The groups were fed a control and three experimental, isocaloric and isonitrogenous grower diets containing 15, 20 and 25% DDGS, respectively, combined with lysine (Lys) and methionine (Met) supplementation until 6 weeks of age. It was found that DDGS inclusion increased the ether extract content of the diets which resulted in higher reduced glutathione (GSH) content and elevated glutathione peroxidase activity (GSHPx) in the liver. However, DDGS addition with Lys and Met supplementation did not influence the malondialdehyde content of the blood and the liver. The oleic acid proportion of the diet showed a close positive correlation with GSH content of the liver. A smaller ratio of methionine and cysteine in the diet with DDGS resulted in significantly higher liver GSH content. GSHPx activity increased parallel with the elevated GSH content of the liver homogenate, suggesting that the enzyme is activated by the actual supply of its co-substrate. In conclusion, the results show that DDGS, even at a high inclusion level combined with Lys and Met supplementation, has no initiative effect on lipid peroxidation in the blood and liver of broiler chickens.

Decreased Glutathione Mediated Antioxidant System After Prolonged Exercise Attenuated by Dammarane Oligo-Sapogenins During Recovery in Liver of Rats

PURPOSE: Chinese herbal medicine ginseng extracts gaining popularity in the recent days due to its tissue unique protective effects against oxidative stress. The objective of the present study was to determine the protective effect of dammarane oligo-sapogenins (DS) against prolonged exercise-induced loss in glutathione and related antioxidant status in liver of rats. METHODS: Two groups of Sprague Dawley rats including placebo (n=60) and DS-treated (n=60) groups received saline and DS substance (60 mg/kg b.w., oral) for 2-week respectively. A set of rats from both groups sacrificed without exercise, and another set of rats sacrificed immediately, 1.5-h and 5-h after prolonged swimming exercise. RESULTS: Hepatic glutathione peroxidase (GPx) activity in placebo was significantly (p<0.05) decreased 5-h after exercise, where DS group showed significantly higher GPx activity. Decreased glutathione reductase (GR) activity immediately after exercise was continued to 1.5-h and 5-h after exercise. However, exercised rats DS group maintained stable GR activity. Glutathione (GSH) levels were drastically decreased (p<0.001) immediately after exercise in both groups. We found restored GSH levels during recovery period, and reached more than normal level at 5-h in DS received group. In this study, all glutathione family parameters were significantly higher in DS pretreated rats at 5-h recovery point compared to placebo group. Nevertheless, prolonged exercise increased superoxide dismutase activity immediately after exercise in both groups, and no change in catalase and malondialdehyde (MDA) levels. CONCLUSIONS: Our results revealed that DS substance can preserve the glutathione system against prolonged exercise-induced loss in liver. This data further suggest that pretreatment of dammarane oligo-substances might be beneficial to athletes for better recovery from oxidative stress.

The effect of indobufen on the activities of selected rat liver phase I and phase II drug metabolizing enzymes, peroxisomal beta-oxidation and hepatic glutathione status.

Oral administration of indobufen to male rats for three days at daily doses of 5, 10 and 20 mg kg-1 resulted in no changes in liver total glutathione, cytosolic glutathione S-transferases or microsomal epoxide hydrolase. Reduced glutathione appeared slightly diminished to about 84% of control at the highest dose level. Microsomal cytochrome P450-dependent ethoxyresorufin O-de-ethylase and pentoxy-resorufin de-alkylase activities were decreased to 64% (not significantly) and 67% of control at the lowest dose level. 6 alpha- and 7 alpha-Hydroxytestosterone activities were decreased to 67 and 68% of control at the highest dose level. Cyanide-insensitive peroxisomal fatty acid beta-oxidation was increased to 223, 261 and 232% of control at doses of 5, 10, and 20 mg kg-1, respectively. The results obtained in this study are indicative of the action of indobufen as a weak peroxisome proliferator in male rat liver, and suggest a slight but toxicologically insignificant inhibitory action of this drug on microsomal cytochrome P450-dependent enzyme activities.

Antioxidant‐rich coffee reduces DNA damage, elevates glutathione status and contributes to weight control: Results from an intervention study

Epidemiological and experimental evidence increasingly suggests coffee consumption to be correlated to prevention or delay of degenerative diseases connected with oxidative cellular stress. In an intervention study comprising 33 healthy volunteers, we examined DNA-protective and antioxidative effects exerted in vivo by daily ingestion of 750 mL of freshly brewed coffee rich in both green coffee bean constituents as well as roast products. The study design encompassed an initial 4 wk of wash-out, followed by 4 wk of coffee intake and 4 wk of second wash-out. At the start and after each study phase blood samples were taken to monitor biomarkers of oxidative stress response. In addition, body weight/composition and intake of energy/nutrients were recorded. In the coffee ingestion period, the primary endpoint, oxidative DNA damage as measured by the Comet assay (± FPG), was markedly reduced (p<0.001). Glutathione level (p<0.05) and GSR-activity (p<0.01) were elevated. Body weight (p<0.01)/body fat (p<0.05) and energy (p<0.001)/nutrient (p<0.001-0.05) intake were reduced. Our results allow to conclude that daily consumption of 3-4 cups of brew from a special Arabica coffee exerts health beneficial effects, as evidenced by reduced oxidative damage, body fat mass and energy/nutrient uptake.

N-Acetylcysteine in Handgrip Exercise: Plasma Thiols and Adverse Reactions

N-acetylcysteine (NAC) is a thiol donor with antioxidant properties that has potential use as an ergogenic aid. However, NAC is associated with adverse reactions that limit its use in humans. The authors evaluated NAC efficacy as a thiol donor before handgrip exercise, measuring changes in serum cysteine and glutathione status and recording adverse reactions in adult subjects across a range of doses. Healthy individuals ingested NAC capsules (9 ± 2 or 18 ± 4 mg/kg) or solution (0, 35, 70, or 140 mg/kg). Venous blood samples were collected and subjects answered a questionnaire about adverse reactions. Low doses of NAC (capsules) did not affect plasma cysteine or glutathione or cause adverse reactions. Adverse reactions to NAC solution were predominantly mild and gastrointestinal (GI). Intensity of GI reactions to 140 mg/kg NAC was significantly higher than placebo (in a.u., 0.67 ± 0.16 vs. 0.07 ± 0.04; p < .05). Plasma cysteine concentration increased with NAC dose from 9.3 ± 0.7 μM (placebo) to 65.3 ± 6.7 μM (140 mg/kg); however, there was no difference (p > .05) in plasma cysteine for 70 mg/kg vs. 140 mg/kg. Similar increases were observed for the ratio of cysteine to total cysteine, which was directly related to handgrip exercise performance. Plasma glutathione was elevated and oxidized glutathione diminished (p < .05) with NAC 140 mg/kg vs. placebo. NAC effects on plasma thiols are maximized by oral administration of 70 mg/kg, a dose that does not cause significant adverse reactions.

Lycopene alters intracellular glutathione status and antioxidant/phase II detoxifying enzymes in human prostate cancer cells

Lcopene, and its metabolites, can reduce prostate cancer (PC) growth. Normal and cancerous prostate cells and subcellular compartments have different redox states. Exposure to lycopene alters cellu...

Variation in glutathione status associated with induction and initiation of diapause in eggs of the bivoltine strain of the silkworm Bombyx mori

For the bivoltine (Dazao) strain of the silkworm Bombyx mori L., diapause expression in progeny is induced by exposure to conditions of 25 °C and continuous illumination (LL) during the maternal generation, whereas an environment of 15 °C and constant darkness (DD) results in nondiapause progeny. Initiation of diapause in progeny can be prevented by treatment of diapause‐programmed eggs with hydrochloric acid (HCl) at approximately 24 h post‐oviposition. To investigate whether glutathione is involved in the regulation of diapause induction and initiation in this species, measurements of total glutathione, reduced glutathione (GSH), oxidised glutathione (GSSG), GSH/GSSG ratio, glutathione S‐transferase (GST) and peroxiredoxins (Prdx) are compared in eggs incubated under LL and DD conditions, and between diapause eggs and those treated with HCl. Compared with DD, eggs incubated under LL have higher total glutathione (GSH + 2GSSG), lower GSH, higher GSSG, a lower GSH/GSSG ratio, lower GST activity and higher Prdx activity at stages 20–25 of maternal embryogenesis. The lower ratio of GSH/GSSG is indicative of pro‐oxidative conditions during diapause induction, which may result from the stronger oxidation of GSH. Compared with HCl‐treated eggs, diapause eggs have lower total glutathione, no difference in GSH, lower GSSG, a higher GSH/GSSG ratio, no difference in GST activity and lower Prdx between 36 and 72 h post‐oviposition. The higher ratio GSH/GSSG is indicative of reducing conditions during diapause initiation, which may a result of the weaker oxidation of GSH. Moreover, variations of Prdx and GST suggest that Prdx rather than GST plays an important role in the oxidation of GSH during the induction and initiation of diapause.