Glutathione and its antiaging and antimelanogenic effects

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Weschawalit S

2017-04-01

Full Text Available Sinee Weschawalit,1 Siriwan Thongthip,2 Phanupong Phutrakool,3 Pravit Asawanonda1 1Department of Medicine, Division of Dermatology, 2Chula Clinical Research Center, 3Chula Data Management Center, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand Background: Previous studies showed that supplementation of reduced form of glutathione (GSH, 500 mg/d has a skin-lightening efficacy in humans. This study was designed to evaluate the influences of both GSH and oxidized form (GSSG, at doses lower than 500 mg/d, on improving skin properties. Patients and methods: A randomized, double-blind, placebo-controlled, parallel, three-arm study was conducted. Healthy female subjects were equally randomized into three groups and took GSH (250 mg/d, GSSG (250 mg/d, or placebo orally for 12 weeks. At each visit at baseline and for 12 weeks, skin features including melanin index, wrinkles, and other relevant biophysical properties were measured. Blood samples were collected for safety monitoring. Results: In generalized estimating equation analyses, melanin index and ultraviolet spots of all sites including face and arm when given GSH and GSSG tended to be lower than placebo. At some sites evaluated, subjects who received GSH showed a significant reduction in wrinkles compared with those taking placebo. A tendency toward increased skin elasticity was observed in GSH and GSSG compared with placebo. There were no serious adverse effects throughout the study. Conclusion: We showed that oral glutathione, 250 mg/d, in both reduced and oxidized forms effectively influences skin properties. Overall, glutathione in both forms are well tolerated. Keywords: glutathione, melanin, pigment, aging, wrinkle, whitening

Effects of reduced glutathion and vitamin c on cisplatin-induced ...

African Journals Online (AJOL)

glutathione peroxidase [GSHPx], catalase [CAT], glutathione reductase [GSHR] activities and gene expression, glutathione [GSH] content) and lipid peroxidation products (malondialdehyde, MDA) in rat liver tissue were measured. CDDP hepatotoxicity was manifested by an increase in serum ALT and AST, elevation of MDA ...

Reduced glutathione and glutathione disulfide in the blood of glucose-6-phosphate dehydrogenase-deficient newborns.

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Gong, Zhen-Hua; Tian, Guo-Li; Huang, Qi-Wei; Wang, Yan-Min; Xu, Hong-Ping

2017-07-20

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is commonly detected during mass screening for neonatal disease. We developed a method to measure reduced glutathione (GSH) and glutathione disulfide (GSSG) using tandem mass spectrometry (MS/MS) for detecting G6PD deficiency. The concentration of GSH and the GSH/GSSG ratio in newborn dry-blood-spot (DBS) screening and in blood plus sodium citrate for test confirmation were examined by MS/MS using labeled glycine as an internal standard. G6PD-deficient newborns had a lower GSH content (242.9 ± 15.9 μmol/L)and GSH/GSSG ratio (14.9 ± 7.2) than neonatal controls (370.0 ± 53.2 μmol/L and 46.7 ± 19.6, respectively). Although the results showed a significance of P blood measured using MS/MS on the first day of sample preparation are consistent with G6PD activity and are helpful for diagnosing G6PD deficiency.

A multidomain fusion protein in Listeria monocytogenes catalyzes the two primary activities for glutathione biosynthesis.

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Gopal, Shubha; Borovok, Ilya; Ofer, Amos; Yanku, Michaela; Cohen, Gerald; Goebel, Werner; Kreft, Jürgen; Aharonowitz, Yair

2005-06-01

Glutathione is the predominant low-molecular-weight peptide thiol present in living organisms and plays a key role in protecting cells against oxygen toxicity. Until now, glutathione synthesis was thought to occur solely through the consecutive action of two physically separate enzymes, gamma-glutamylcysteine ligase and glutathione synthetase. In this report we demonstrate that Listeria monocytogenes contains a novel multidomain protein (termed GshF) that carries out complete synthesis of glutathione. Evidence for this comes from experiments which showed that in vitro recombinant GshF directs the formation of glutathione from its constituent amino acids and the in vivo effect of a mutation in GshF that abolishes glutathione synthesis, results in accumulation of the intermediate gamma-glutamylcysteine, and causes hypersensitivity to oxidative agents. We identified GshF orthologs, consisting of a gamma-glutamylcysteine ligase (GshA) domain fused to an ATP-grasp domain, in 20 gram-positive and gram-negative bacteria. Remarkably, 95% of these bacteria are mammalian pathogens. A plausible origin for GshF-dependent glutathione biosynthesis in these bacteria was the recruitment by a GshA ancestor gene of an ATP-grasp gene and the subsequent spread of the fusion gene between mammalian hosts, most likely by horizontal gene transfer.

Ebselen exerts antifungal activity by regulating glutathione (GSH) and reactive oxygen species (ROS) production in fungal cells.

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Thangamani, Shankar; Eldesouky, Hassan E; Mohammad, Haroon; Pascuzzi, Pete E; Avramova, Larisa; Hazbun, Tony R; Seleem, Mohamed N

2017-01-01

Ebselen, an organoselenium compound and a clinically safe molecule has been reported to possess potent antifungal activity, but its antifungal mechanism of action and in vivo antifungal activity remain unclear. The antifungal effect of ebselen was tested against Candida albicans, C. glabrata, C. tropicalis, C. parapsilosis, Cryptococcus neoformans, and C. gattii clinical isolates. Chemogenomic profiling and biochemical assays were employed to identify the antifungal target of ebselen. Ebselen's antifungal activity in vivo was investigated in a Caenorhabditis elegans animal model. Ebselen exhibits potent antifungal activity against both Candida spp. and Cryptococcus spp., at concentrations ranging from 0.5 to 2μg/ml. Ebselen rapidly eradicates a high fungal inoculum within 2h of treatment. Investigation of the drug's antifungal mechanism of action indicates that ebselen depletes intracellular glutathione (GSH) levels, leading to increased production of reactive oxygen species (ROS), and thereby disturbs the redox homeostasis in fungal cells. Examination of ebselen's in vivo antifungal activity in two Caenorhabditis elegans models of infection demonstrate that ebselen is superior to conventional antifungal drugs (fluconazole, flucytosine and amphotericin) in reducing Candida and Cryptococcus fungal load. Ebselen possesses potent antifungal activity against clinically relevant isolates of both Candida and Cryptococcus by regulating GSH and ROS production. The potent in vivo antifungal activity of ebselen supports further investigation for repurposing it for use as an antifungal agent. The present study shows that ebselen targets glutathione and also support that glutathione as a potential target for antifungal drug development. Copyright © 2016 Elsevier B.V. All rights reserved.

Glutathione system participation in thoracic aneurysms from patients with Marfan syndrome.

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Zúñiga-Muñoz, Alejandra María; Pérez-Torres, Israel; Guarner-Lans, Verónica; Núñez-Garrido, Elías; Velázquez Espejel, Rodrigo; Huesca-Gómez, Claudia; Gamboa-Ávila, Ricardo; Soto, María Elena

2017-05-01

Aortic dilatation in Marfan syndrome (MFS) is progressive. It is associated with oxidative stress and endothelial dysfunction that contribute to the early acute dissection of the vessel and can result in rupture of the aorta and sudden death. We evaluated the participation of the glutathione (GSH) system, which could be involved in the mechanisms that promote the formation and progression of the aortic aneurysms in MFS patients. Aortic aneurysm tissue was obtained during chest surgery from eight control subjects and 14 MFS patients. Spectrophotometrical determination of activity of glutathione peroxidase (GPx), glutathione-S-transferase (GST), glutathione reductase (GR), lipid peroxidation (LPO) index, carbonylation, total antioxidant capacity (TAC), and concentration of reduced and oxidized glutathione (GSH and GSSG respectively), was performed in the homogenate from aortic aneurysm tissue. LPO index, carbonylation, TGF-β1, and GR activity were increased in MFS patients (p < 0.04), while TAC, GSH/GSSG ratio, GPx, and GST activity were significantly decreased (p < 0.04). The depletion of GSH, in spite of the elevated activity of GR, not only diminished the activity of GSH-depend GST and GPx, but increased LPO, carbonylation and decreased TAC. These changes could promote the structural and functional alterations in the thoracic aorta of MFS patients.

Fluorescence detection of glutathione and oxidized glutathione in blood with a NIR-excitable cyanine probe

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Liu, Chang-hui; Qi, Feng-pei; Wen, Fu-bin; Long, Li-ping; Liu, Ai-juan; Yang, Rong-hua

2018-04-01

Cyanine has been widely utilized as a near infrared (NIR) fluorophore for detection of glutathione (GSH). However, the excitation of most of the reported cyanine-based probes was less than 800 nm, which inevitably induce biological background absorption and lower the sensitivity, limiting their use for detection of GSH in blood samples. To address this issue, here, a heptamethine cyanine probe (DNIR), with a NIR excitation wavelength at 804 nm and a NIR emission wavelength at 832 nm, is employed for the detection of GSH and its oxidized form (GSSG) in blood. The probe displays excellent selectivity for GSH over GSSG and other amino acids, and rapid response to GSH, in particular a good property for indirect detection of GSSG in the presence of enzyme glutathione reductase and the reducing agent nicotinamideadenine dinucleotide phosphate, without further separation prior to fluorescent measurement. To the best of our knowledge, this is the first attempt to explore NIR fluorescent approach for the simultaneous assay of GSH and GSSG in blood. As such, we expect that our fluorescence sensors with both NIR excitation and NIR emission make this strategy suitable for the application in complex physiological systems.

Reduced glutathione concentration and glutathione reductase activity in various rat tissues after the administration of some radioprotective agents

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Pulpanova, J.; Kovarova, H.; Ledvina, M.

1982-01-01

The concentrations of reduced glutathione (GSH) and activity of glutathione reductase were investigated in rat liver, kidney and spleen after intraperitoneal administration of cystamine (50 mg/kg), mexamine (10 mg/kg), or a mixture of cystamine with mexamine (20 + 10 mg/kg). The GSH concentration increased after the administration of cystamine in the liver (maximum between the 20th and 30th min), in the kidney and spleen (maximum after 60 min). The cystamine + mexamine mixture also caused a significant increase of the GSH concentration in all the organs investigated; however, the values increased at earlier intervals as after the cystamine administration. No substantial effect was shown in the case of the mexamine administration, only 30 min after the administration the values were higher. The activity of glutathione reductase was significantly lower over the entire period examined. This was found in the liver and kidney as after the administration of cystamine, as after the radioprotective mixture. There was also a less pronounced inhibition of the enzyme activity in the spleen. Mexamine as a single radioprotector had practically no influence on the activity. (author)

Application of superparamagnetic microspheres for affinity adsorption and purification of glutathione

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Wang Qiang; Guan Yueping; Yang Mingzhu

2012-01-01

The superparamagnetic poly-(MA–DVB) microspheres with micron size were synthesized by the modified suspension polymerization method. Adsorption of glutathione by magnetic poly-(MA–DVB) microspheres with IDA-copper was investigated. The effect of solution pH value, affinity adsorption and desorption of glutathione was studied. The results showed that the optimum pH value for glutathione adsorption was found at pH=3.5, the maximum capacity for glutathione of magnetic poly-(MA–DVB) microspheres was estimated at 42.4 mg/g by fitting the experimental data to the Langmuir equation. The adsorption equilibrium of glutathione was obtained in about 10 min and the adsorbed glutathione was desorbed from the magnetic microspheres in about 30 min using NaCl buffer solution. The magnetic microspheres could be repeatedly utilized for the affinity adsorption of glutathione. - Highlights: ► The magnetic microsphere with surface IDA–Cu groups was synthesized. ► The magnetic microspheres were applied for adsorption of GSH. ► The adsorption–desorption of glutathione was investigated. ► The maximum adsorption capacity of GSH was fitted at 42.4 mg/g.

Prolonged fasting increases glutathione biosynthesis in postweaned northern elephant seals

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Vázquez-Medina, José Pablo; Zenteno-Savín, Tania; Forman, Henry Jay; Crocker, Daniel E.; Ortiz, Rudy M.

2011-01-01

SUMMARY Northern elephant seals experience prolonged periods of absolute food and water deprivation (fasting) while breeding, molting or weaning. The postweaning fast in elephant seals is characterized by increases in the renin–angiotensin system, expression of the oxidant-producing protein Nox4, and NADPH oxidase activity; however, these increases are not correlated with increased oxidative damage or inflammation. Glutathione (GSH) is a potent reductant and a cofactor for glutathione peroxidases (GPx), glutathione-S transferases (GST) and 1-cys peroxiredoxin (PrxVI) and thus contributes to the removal of hydroperoxides, preventing oxidative damage. The effects of prolonged food deprivation on the GSH system are not well described in mammals. To test our hypothesis that GSH biosynthesis increases with fasting in postweaned elephant seals, we measured circulating and muscle GSH content at the early and late phases of the postweaning fast in elephant seals along with the activity/protein content of glutamate-cysteine ligase [GCL; catalytic (GCLc) and modulatory (GCLm) subunits], γ-glutamyl transpeptidase (GGT), glutathione disulphide reductase (GR), glucose-6-phosphate dehydrogenase (G6PDH), GST and PrxVI, as well as plasma changes in γ-glutamyl amino acids, glutamate and glutamine. GSH increased two- to four-fold with fasting along with a 40–50% increase in the content of GCLm and GCLc, a 75% increase in GGT activity, a two- to 2.5-fold increase in GR, G6PDH and GST activities and a 30% increase in PrxVI content. Plasma γ-glutamyl glutamine, γ-glutamyl isoleucine and γ-glutamyl methionine also increased with fasting whereas glutamate and glutamine decreased. Results indicate that GSH biosynthesis increases with fasting and that GSH contributes to counteracting hydroperoxide production, preventing oxidative damage in fasting seals. PMID:21430206

Glutathione--linking cell proliferation to oxidative stress.

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Diaz-Vivancos, Pedro; de Simone, Ambra; Kiddle, Guy; Foyer, Christine H

2015-12-01

The multifaceted functions of reduced glutathione (gamma-glutamyl-cysteinyl-glycine; GSH) continue to fascinate plants and animal scientists, not least because of the dynamic relationships between GSH and reactive oxygen species (ROS) that underpin reduction/oxidation (redox) regulation and signalling. Here we consider the respective roles of ROS and GSH in the regulation of plant growth, with a particular focus on regulation of the plant cell cycle. Glutathione is discussed not only as a crucial low molecular weight redox buffer that shields nuclear processes against oxidative challenge but also a flexible regulator of genetic and epigenetic functions. The intracellular compartmentalization of GSH during the cell cycle is remarkably consistent in plants and animals. Moreover, measurements of in vivo glutathione redox potentials reveal that the cellular environment is much more reducing than predicted from GSH/GSSG ratios measured in tissue extracts. The redox potential of the cytosol and nuclei of non-dividing plant cells is about -300 mV. This relatively low redox potential maintained even in cells experiencing oxidative stress by a number of mechanisms including vacuolar sequestration of GSSG. We propose that regulated ROS production linked to glutathione-mediated signalling events are the hallmark of viable cells within a changing and challenging environment. The concept that the cell cycle in animals is subject to redox controls is well established but little is known about how ROS and GSH regulate this process in plants. However, it is increasingly likely that redox controls exist in plants, although possibly through different pathways. Moreover, redox-regulated proteins that function in cell cycle checkpoints remain to be identified in plants. While GSH-responsive genes have now been identified, the mechanisms that mediate and regulate protein glutathionylation in plants remain poorly defined. The nuclear GSH pool provides an appropriate redox environment

Mitochondrial Swelling Induced by Glutathione

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Lehninger, Albert L.; Schneider, Marion

1959-01-01

Reduced glutathione, in concentrations approximating those occurring in intact rat liver, causes swelling of rat liver mitochondria in vitro which is different in kinetics and extent from that yielded by L-thyroxine. The effect is also given by cysteine, which is more active, and reduced coenzyme A, but not by L-ascorbate, cystine, or oxidized glutathione. The optimum pH is 6.5, whereas thyroxine-induced swelling is optimal at pH 7.5. The GSH-induced swelling is not inhibited by DNP or dicumarol, nor by high concentrations of sucrose, serum albumin, or polyvinylpyrrolidone, in contrast to thyroxine-induced swelling. ATP inhibits the GSH swelling, but ADP and AMP are ineffective. Mn-+ is a very potent inhibitor, but Mg++ is ineffective. Ethylenediaminetetraacetate is also an effective inhibitor of GSH-induced swelling. The respiratory inhibitors amytal and antimycin A do not inhibit the swelling action of GSH, but cyanide does; these findings are consistent with the view that the oxidation-reduction state of the respiratory chain between cytochrome c and oxygen is a determinant of GSH-induced swelling. Reversal of GSH-induced swelling by osmotic means or by ATP in KCl media could not be observed. Large losses of nucleotides and protein occur during the swelling by GSH, suggesting that the action is irreversible. The characteristically drastic swelling action of GSH could be prevented if L-thyroxine was also present in the medium. PMID:13630941

Depression of biliary glutathione excretion by chronic ethanol feeding in the rat

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Vendemiale, G.; Jayatilleke, E.; Shaw, S.; Lieber, C.S.

1984-01-01

The effects of chronic alcohol feeding on biliary glutathione excretion were studied in rats pair fed diets containing either ethanol (36% of total energy) or isocaloric carbohydrate for 4-6 weeks. An exteriorized biliary-duodenal fistula was established and total glutathione (GSH) and oxidized glutathione (GSSG) were measured. A significant decrease was observed in rats fed alcohol chronically compared to their pair fed controls in the biliary excretion of GSH (55.7 +/- 37.0 vs 243.1 +/- 29.0 μg/ml bile, p 35 -L-methionine incorporation into hepatic and biliary GSH was unchanged or even increased after chronic ethanol feeding. 22 references, 4 figures

The antioxidant master glutathione and periodontal health

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Vivek Kumar Bains

2015-01-01

Full Text Available Glutathione, considered to be the master antioxidant (AO, is the most-important redox regulator that controls inflammatory processes, and thus damage to the periodontium. Periodontitis patients have reduced total AO capacity in whole saliva, and lower concentrations of reduced glutathione (GSH in serum and gingival crevicular fluid, and periodontal therapy restores the redox balance. Therapeutic considerations for the adjunctive use of glutathione in management of periodontitis, in limiting the tissue damage associated with oxidative stress, and enhancing wound healing cannot be underestimated, but need to be evaluated further through multi-centered randomized controlled trials.

Correction of glutathione metabolism in the liver of albino rats affected by low radiation doses

International Nuclear Information System (INIS)

Moiseenok, A.G.; Slyshenkov, V.S.; Khomich, T.I.; Zimatkina, T.I.; Kanunnikova, N.P.

1997-01-01

The levels of total glutathione GSH, GSSG and the activities of glutathione reductase and glutathione peroxidase were studied in the liver of adult albino rats subjected to 3-fold external γ-irradiation throughout 2 weeks at the overall dose of 0.75 Gy after 15 h, 2 and 5 days from the last irradiation. Some animals were injected intraperitoneally with the pantothenate containing complex > 3 times on days 1-3 before the irradiation. The radiation related decrease of GSH, GSH/GSSG and the total glutathione level was prevented by the prophylactic administration of the complex and probably at the expense of the activation of the G-SH biosynthesis and/or transport in the liver by the CoA biosynthetic precursor. (author)

Glutathione: an intracellular and extracellular protective agent in Salmonella typhimurium and Escherichia coli

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Owens, R.A.

1986-01-01

Levels of glutathione, were measured in several aerobically grown strains of Salmonella typhimurium and Escherichia coli. External accumulation of GSH was inhibited by 30 mM NaN 3 . Thus, GSH export may be energy dependent. Greater than 50% of the glutathione detected in the media was in the reduced form. Since the oxidized glutathione in the media could be accounted for by oxidation during aerobic incubation as well as in sample processing, the glutathione was predominantly exported in the reduced form. Extracellular glutathione was detected in log phase cultures of 2 out of 2 E. coli strains and 6 of 8 Salmonella strains tested. Two-dimensional paper chromatography of supernatants from cultures labelled with Na 2 35 SO 4 confirmed the presence of GSH and revealed five other sulfur-containing compounds in the media of Salmonella and E. coli cultures. Since media from cultures of an E. coli GSH - strain contained compounds with identical R/sub f/'s, the five unidentified compounds were not derivatives of GSH. The addition of 26 μM GSH to cultures of TA1534 partially protected the bacteria from the toxic effects of 54 μM N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). When MNNG was preincubated with equimolar GSH, the mutagenicity of the MNNG was neutralized. The addition of micromolar GSH to cultures and E. coli GSH - strain protected the cells from growth inhibition by micromolar concentrations of mercuric chloride, silver nitrate, cisplatin, cadmium chloride, and iodoacetamide. The data presented demonstrate that micromolar concentrations of external GSH can significantly shorten the recovery time of cells after exposure to toxic agents in the environment

1-Methyl-4-phenylpyridinium-induced alterations of glutathione status in immortalized rat dopaminergic neurons

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Drechsel, Derek A.; Liang, L.-P.; Patel, Manisha

2007-01-01

Decreased glutathione levels associated with increased oxidative stress are a hallmark of numerous neurodegenerative diseases, including Parkinson's disease. GSH is an important molecule that serves as an anti-oxidant and is also a major determinant of cellular redox environment. Previous studies have demonstrated that neurotoxins can cause changes in reduced and oxidized GSH levels; however, information regarding steady state levels remains unexplored. The goal of this study was to characterize changes in cellular GSH levels and its regulatory enzymes in a dopaminergic cell line (N27) following treatment with the Parkinsonian toxin, 1-methyl-4-phenylpyridinium (MPP + ). Cellular GSH levels were initially significantly decreased 12 h after treatment, but subsequently recovered to values greater than controls by 24 h. However, oxidized glutathione (GSSG) levels were increased 24 h following treatment, concomitant with a decrease in GSH/GSSG ratio prior to cell death. In accordance with these changes, ROS levels were also increased, confirming the presence of oxidative stress. Decreased enzymatic activities of glutathione reductase and glutamate-cysteine ligase by 20-25% were observed at early time points and partly account for changes in GSH levels after MPP + exposure. Additionally, glutathione peroxidase activity was increased 24 h following treatment. MPP + treatment was not associated with increased efflux of glutathione to the medium. These data further elucidate the mechanisms underlying GSH depletion in response to the Parkinsonian toxin, MPP +

[Alternative nutrition and glutathione levels].

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Krajcovicová-Kudlácková, M; Simoncic, R; Béderová, A; Brtková, A; Magálová, T; Barteková, S

1999-08-30

Low protein quality and quantity is reported to be a possible risk of alternative nutrition. Pulses contain 18-41% of methionine in relation to reference protein, moreover, its content in cereals is by one half lower. Therefore vegetarians and vegans may have an insufficient intake of sulphur-containing amino acids that may subsequently affect glutathione values (precursors of its synthesis). In groups of adults on an alternative diet--lactoovovegetarians (n = 47) and vegans (n = 44) aged 19-62 years with average duration on a vegetarian or vegan diet of 7.6 and 4.9 years, respectively, glutathione levels (GSH) were measured in erythrocytes (spectrophotometrically), as well as the activity of GSH-dependent enzymes. As nutritional control (n = 42) served an average sample of omnivores selected from a group of 489 examined, apparently healthy subjects of the same age range living in the same region. One to low protein intake (56% of RDA) exclusively of plant origin significantly lower levels of total proteins were observed in vegans with a 16% frequency of hypoproteinaemia (vs 0% in omnivores). In comparison to omnivores a significantly lower glutathione level was found (4.28 +/- 0.12 vs 4.84 +/- 0.14 mumol/g Hb, P vegan diet also in adult age.

Glutathione and its dependent enzymes' modulatory responses to toxic metals and metalloids in fish--a review.

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Srikanth, K; Pereira, E; Duarte, A C; Ahmad, I

2013-04-01

Toxic metals and metalloid are being rapidly added from multiple pathways to aquatic ecosystem and causing severe threats to inhabiting fauna including fish. Being common in all the type of aquatic ecosystems such as freshwater, marine and brackish water fish are the first to get prone to toxic metals and metalloids. In addition to a number of physiological/biochemical alterations, toxic metals and metalloids cause enhanced generation of varied reactive oxygen species (ROS) ultimately leading to a situation called oxidative stress. However, as an important component of antioxidant defence system in fish, the tripeptide glutathione (GSH) directly or indirectly regulates the scavenging of ROS and their reaction products. Additionally, several other GSH-associated enzymes such as GSH reductase (GR, EC 1.6.4.2), GSH peroxidase (EC 1.11.1.9), and GSH sulfotransferase (glutathione-S-transferase (GST), EC 2.5.1.18) cumulatively protect fish against ROS and their reaction products accrued anomalies under toxic metals and metalloids stress conditions. The current review highlights recent research findings on the modulation of GSH, its redox couple (reduced glutathione/oxidised glutathione), and other GSH-related enzymes (GR, glutathione peroxidase, GST) involved in the detoxification of harmful ROS and their reaction products in toxic metals and metalloids-exposed fish.

Enzymatic Production of Glutathione by Bifunctional γ-Glutamylcysteine Synthetase/Glutathione Synthetase Coupled with In Vitro Acetate Kinase-Based ATP Generation.

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Jiang, Yu; Tao, Rongsheng; Shen, Zhengquan; Sun, Liangdong; Zhu, Fuyun; Yang, Sheng

2016-12-01

Glutathione (γ-glutamyl-L-cysteinylglycine, GSH) is a pharmaceutical compound often used in food additives and the cosmetics industry. GSH can be produced biologically from L-glutamic acid, L-cysteine, and glycine through an enzymatic process traditionally involving two sequential adenosine triphosphate (ATP)-dependent reactions catalyzed by γ-glutamylcysteine synthetase (γ-GCS or GSHI, EC 6.3.2.2) and GSH synthetase (GS or GSHII, EC 6.3.2.3). Here, we report the enzymatic production of GSH by recombinant cell-free bifunctional γ-glutamylcysteine synthetase/glutathione synthetase (γ-GCS-GS or GshF) coupled with in vitro acetate kinase-based ATP generation. GSH production by an acetate kinase-integrated Escherichia coli Rosetta(DE3) mutant expressing Streptococcus thermophilus GshF reached 18.3 ± 0.1 g l -1 (59.5 ± 0.3 mM) within 3 h, with a molar yield of 0.75 ± 0.00 mol mol -1 added cysteine and a productivity of 6.1 ± 0.0 g l -1  h -1 . This is the highest GSH titer reported to date. This newly developed biocatalytic process offers a promising approach for meeting the industrial requirements for GSH production.

Enact of Glutathione(GSH/GSSG) Contents of Fermented Ginseng on the γ-irradiated Liver of Mice

International Nuclear Information System (INIS)

Ko, In Ho

2006-01-01

The radioprotective effects of white and fermented ginseng on liver damage induced by 60 Co γ-ray were investigated. To one group of ICR male mice were given white(150 mg/kg/day for 7 days, orally) and fermented ginseng(150 mg/kg/day for 7 days, orally) before 60 Co γ--ray irradiation. To another group were irradiated by 5 Gy(1.01 Gy/min) dose of 60 Co γ--ray. Contrast group were given with saline(0.1 mL). The levels of reduced(GSH) and oxidized(GSSG) glutathione in liver tissue were measured. In the fermented(150 mg/kg) and white ginseng(150 mg/kg) groups than irradiation group, the GSH levels were significantly increased, but the GSSG levels were significantly decreased. The ratio of GSSG/total GSH was significantly decreased in the fermented(150 mg/kg) and white ginseng(150 mg/kg) groups than irradiation group. In the fermented(150 mg/kg) groups than white ginseng(150 mg/kg) groups the GSH levels were significantly increased. The radioprotective effects of fermented(150 mg/kg) groups than white ginseng(150 mg/kg) groups were increased.

Enact of Glutathione(GSH/GSSG) Contents of Fermented Ginseng on the {gamma}-irradiated Liver of Mice

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Ko, In Ho [Dept. of Radiology Technology, Jeju Halla College, Jeju (Korea, Republic of)

2006-03-15

The radioprotective effects of white and fermented ginseng on liver damage induced by {sup 60}Co {gamma}-ray were investigated. To one group of ICR male mice were given white(150 mg/kg/day for 7 days, orally) and fermented ginseng(150 mg/kg/day for 7 days, orally) before {sup 60}Co {gamma}--ray irradiation. To another group were irradiated by 5 Gy(1.01 Gy/min) dose of {sup 60}Co {gamma}--ray. Contrast group were given with saline(0.1 mL). The levels of reduced(GSH) and oxidized(GSSG) glutathione in liver tissue were measured. In the fermented(150 mg/kg) and white ginseng(150 mg/kg) groups than irradiation group, the GSH levels were significantly increased, but the GSSG levels were significantly decreased. The ratio of GSSG/total GSH was significantly decreased in the fermented(150 mg/kg) and white ginseng(150 mg/kg) groups than irradiation group. In the fermented(150 mg/kg) groups than white ginseng(150 mg/kg) groups the GSH levels were significantly increased. The radioprotective effects of fermented(150 mg/kg) groups than white ginseng(150 mg/kg) groups were increased.

Glutathione.

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Noctor, Graham; Queval, Guillaume; Mhamdi, Amna; Chaouch, Sejir; Foyer, Christine H

2011-01-01

Glutathione is a simple sulfur compound composed of three amino acids and the major non-protein thiol in many organisms, including plants. The functions of glutathione are manifold but notably include redox-homeostatic buffering. Glutathione status is modulated by oxidants as well as by nutritional and other factors, and can influence protein structure and activity through changes in thiol-disulfide balance. For these reasons, glutathione is a transducer that integrates environmental information into the cellular network. While the mechanistic details of this function remain to be fully elucidated, accumulating evidence points to important roles for glutathione and glutathione-dependent proteins in phytohormone signaling and in defense against biotic stress. Work in Arabidopsis is beginning to identify the processes that govern glutathione status and that link it to signaling pathways. As well as providing an overview of the components that regulate glutathione homeostasis (synthesis, degradation, transport, and redox turnover), the present discussion considers the roles of this metabolite in physiological processes such as light signaling, cell death, and defense against microbial pathogen and herbivores.

Hepatic glutathione and glutathione S-transferase in selenium deficiency and toxicity in the chick

International Nuclear Information System (INIS)

Kim, Y. S.

1989-01-01

First, the hepatic activity of GSH-T CDNB was increased only under conditions of severe oxidative stress produced by combined Se- and vitamin E (VE)-deficiency, indicating that VE also affects GSH metabolism. Second, the incorporation of 35 S-methionine into GSH and protein was about 4- and 2-fold higher, respectively, in Se- and VE-deficient chick hepatocytes as compared to controls. Third, chicks injected with the glutathione peroxidase (SeGSHpx) inhibitor, aurothioglucose (AuTG), showed increase hepatic GSH-T CDNB activity and plasma GSH concentration regardless of their Se status. Fourth, the effect of ascorbic acid (AA), on GSH metabolism was studied. Chicks fed 1000 ppm AA showed decreased hepatic GSH concentration compared to chicks fed no AA in a Se- and VE-deficient diet. Fifth, chicks fed excess Se showed increase hepatic activity of GSH-T CDNB and GSH concentration regardless of VE status

Manipulation of Glutathione and Amino Acid Biosynthesis in the Chloroplast1

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Noctor, Graham; Arisi, Ana-Carolina M.; Jouanin, Lise; Foyer, Christine H.

1998-01-01

Poplars (Populus tremula × Populus alba) were transformed to overexpress Escherichia coli γ-glutamylcysteine synthetase (γ-ECS) or glutathione synthetase in the chloroplast. Five independent lines of each transformant strongly expressed the introduced gene and possessed markedly enhanced activity of the gene product. Glutathione (GSH) contents were unaffected by high chloroplastic glutathione synthetase activity. Enhanced chloroplastic γ-ECS activity markedly increased γ-glutamylcysteine and GSH levels. These effects are similar to those previously observed in poplars overexpressing these enzymes in the cytosol. Similar to cytosolic γ-ECS overexpression, chloroplastic overexpression did not deplete foliar cysteine or methionine pools and did not lead to morphological changes. Light was required for maximal accumulation of GSH in poplars overexpressing γ-ECS in the chloroplast. High chloroplastic, but not cytosolic, γ-ECS activities were accompanied by increases in amino acids synthesized in the chloroplast. We conclude that (a) GSH synthesis can occur in the chloroplast and the cytosol and may be up-regulated in both compartments by increased γ-ECS activity, (b) interactions between GSH synthesis and the pathways supplying the necessary substrates are similar in both compartments, and (c) chloroplastic up-regulation of GSH synthesis is associated with an activating effect on the synthesis of specific amino acids formed in the chloroplast. PMID:9765532

The diverse roles of glutathione-associated cell resistance against hypericin photodynamic therapy

Directory of Open Access Journals (Sweden)

Theodossis A. Theodossiou

2017-08-01

Full Text Available The diverse responses of different cancers to treatments such as photodynamic therapy of cancer (PDT have fueled a growing need for reliable predictive markers for treatment outcome. In the present work we have studied the differential response of two phenotypically and genotypically different breast adenocarcinoma cell lines, MCF7 and MDA-MB-231, to hypericin PDT (HYP-PDT. MDA-MB-231 cells were 70% more sensitive to HYP PDT than MCF7 cells at LD50. MCF7 were found to express a substantially higher level of glutathione peroxidase (GPX4 than MDA-MB-231, while MDA-MB-231 differentially expressed glutathione-S-transferase (GSTP1, mainly used for xenobiotic detoxification. Eighty % reduction of intracellular glutathione (GSH by buthionine sulfoximine (BSO, largely enhanced the sensitivity of the GSTP1 expressing MDA-MB-231 cells to HYP-PDT, but not in MCF7 cells. Further inhibition of the GSH reduction however by carmustine (BCNU resulted in an enhanced sensitivity of MCF7 to HYP-PDT. HYP loading studies suggested that HYP can be a substrate of GSTP for GSH conjugation as BSO enhanced the cellular HYP accumulation by 20% in MDA-MB-231 cells, but not in MCF7 cells. Studies in solutions showed that L-cysteine can bind the GSTP substrate CDNB in the absence of GSTP. This means that the GSTP-lacking MCF7 may use L-cysteine for xenobiotic detoxification, especially during GSH synthesis inhibition, which leads to L-cysteine build-up. This was confirmed by the lowered accumulation of HYP in both cell lines in the presence of BSO and the L-cysteine source NAC. NAC reduced the sensitivity of MCF7, but not MDA-MB-231, cells to HYP PDT which is in accordance with the antioxidant effects of L-cysteine and its potential as a GSTP substrate. As a conclusion we have herein shown that the different GSH based cell defense mechanisms can be utilized as predictive markers for the outcome of PDT and as a guide for selecting optimal combination strategies. Keywords

Balneotherapy and platelet glutathione metabolism in type II diabetic patients

Science.gov (United States)

Ohtsuka, Yoshinori; Yabunaka, Noriyuki; Watanabe, Ichiro; Noro, Hiroshi; Agishi, Yuko

1996-09-01

Effects of balneotherapy on platelet glutathione metabolism were investigated in 12 type II (non-insulin-dependent) diabetic patients. Levels of the reduced form of glutathione (GSH) on admission were well correlated with those of fasting plasma glucose (FPG; r=0.692, Pbalneotherapy, the mean level of GSH showed no changes; however, in well-controlled patients (FPG 150 mg/dl), the value decreased ( Pbalneotherapy, the activity increased in 5 patients, decreased in 3 patients and showed no changes (alteration within ±3%) in all the other patients. From these findings in diabetic patients we concluded: (1) platelet GSH synthesis appeared to be induced in response to oxidative stress; (2) lowered GPX activities indicated that the antioxidative defense system was impaired; and (3) platelet glutathione metabolism was partially improved by 4 weeks balneotherapy, an effect thought to be dependent on the control status of plasma glucose levels. It is suggested that balneotherapy is beneficial for patients whose platelet antioxidative defense system is damaged, such as those with diabetes mellitus and coronary heart disease.

Oxidative-stress detoxification and signalling in cyanobacteria: the crucial glutathione synthesis pathway supports the production of ergothioneine and ophthalmate.

Science.gov (United States)

Narainsamy, Kinsley; Farci, Sandrine; Braun, Emilie; Junot, Christophe; Cassier-Chauvat, Corinne; Chauvat, Franck

2016-04-01

Using genetics and metabolomics we investigated the synthesis (gshA and gshB genes) and catabolism (ggt) of the conserved antioxidant glutathione in the model cyanobacterium Synechocystis PCC6803. These three genes are crucial to Synechocystis, in agreement with the proposed invention of glutathione by ancient cyanobacteria to protect themselves against the toxicity of oxygen they produced through photosynthesis. Consistent with their indispensability, gshA and gshB also operate in the production of another antioxidant, ergothioneine, as well as of the glutathione analogues ophthalmate and norophthalmate. Furthermore, we show that glutathione, ophthalmate and norophthalmate are accumulated in cells stressed by glucose, and that the two glutathione-dependent glyoxalase enzymes operate in the protection against glucose and its catabolite methylglyoxal. These findings are interesting because ophthalmate and norophthalmate were observed only in mammals so far, where ophthalmate is regarded as a biomarker of glutathione depletion. Instead, our data suggest that ophthalmate and norophthalmate are stress-induced markers of cysteine depletion triggered by its accelerated incorporation into glutathione, to face its increased demand for detoxification purposes. Hence, Synechocystis is an attractive model for the analysis of the role of glutathione, ergothioneine, ophthalmate and norophthalmate, in signalling and detoxification of oxidants and metabolic by-products. © 2015 John Wiley & Sons Ltd.

[Concentration of glutathione (GSH), ascorbic acid (vitamin C) and substances reacting with thiobarbituric acid (TBA-rs) in single human brain metastases].

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Dudek, Henryk; Farbiszewski, Ryszard; Rydzewska, Maria; Michno, Tadeusz; Kozłowski, Andrzej

2005-01-01

The aim of the study was to estimate the concentration of glutathione (GSH), ascorbic acid (vitamin C) and thiobarbituric acid (TBA-rs) in single human brain metastases and histologically unchanged nerve tissue. The research was conducted on fragments of neoplasmatic tissue collected from 45 patients undergoing surgery in the Department of Neurosurgery, Medical University of Białystok in years 1996-2002. Concentration of GSH was evaluated using the GSH-400 method, vitamin C using the method of Kyaw and TBA-rs using the method of Salaris and Babs. It has been found that there is a decrease of concentration of GSH and vitamin C and a considerable increase (p TBA-rs in investigated single brain human metastasis in correlation to the concentration of the mentioned above substances in unchanged nerve tissue.

CHARACTERIZATION OF DANSYLATED CYSTEINE, CYSTINE, GLUTATHIONE, AND GLUTATHIONE DISULFIDE BY NARROW BORE LIQUID CHROMATOGRAPHY - ELECTROSPRAY IONIZATION MASS SPECTROMETRY

Science.gov (United States)

A method using reversed phase high performance liquid chromtography/electrospray ionization-mass spectrometry (RP-LC/ESI-MS) has been developed to confirm the dientity of dansylated derivatives of cysteine (C) and glutathione (GSH), and their respective dimers, cystine (CSSC) and...

Determination of glutaredoxin enzyme activity and protein S-glutathionylation using fluorescent eosin-glutathione.

Science.gov (United States)

Coppo, Lucia; Montano, Sergio J; Padilla, Alicia C; Holmgren, Arne

2016-04-15

Glutaredoxins catalyze glutathione-dependent disulfide oxidoreductions, particularly reduction of glutathione (GSH)-protein mixed disulfides. Mammalian glutaredoxins are present in the cytosol/nucleus as Grx1 or in mitochondria as Grx2a. Here we describe di-eosin-glutathione disulfide (Di-E-GSSG) as a new tool to study glutaredoxin (Grx) activity. Di-E-GSSG has almost no fluorescence in its disulfide form due to self-quenching, whereas the reduced form (E-GSH) has a large fluorescence emission at 545 nm after excitation at 520 nm. Di-E-GSSG was a very poor substrate for glutathione reductase, but we discovered that the molecule was an excellent substrate for glutaredoxin in a coupled assay system with GSH, nicotinamide adenine dinucleotide phosphate (NADPH), and glutathione reductase or with lipoamide, NADH, and lipoamide dehydrogenase. In addition, Di-E-GSSG was used to glutathionylate the free SH group of bovine serum albumin (BSA), yielding eosin-glutathionylated BSA (E-GS-BSA) readily observed in ultraviolet (UV) light. E-GS-BSA also displayed a quenched fluorescence, and its Grx-catalyzed reduction could be followed by the formation of E-GSH by fluorescence emission using microtiter plates. This way of measuring Grx activity provided an ultrasensitive method that detected Grx1 and Grx2 at picomolar levels. Human Grx1 was readily quantified in 40 μl of plasma and determined to be 680 ± 208 pM in healthy controls. Copyright © 2016 Elsevier Inc. All rights reserved.

Impaired glutathione synthesis in schizophrenia

DEFF Research Database (Denmark)

Gysin, René; Kraftsik, Rudolf; Sandell, Julie

2007-01-01

Schizophrenia is a complex multifactorial brain disorder with a genetic component. Convergent evidence has implicated oxidative stress and glutathione (GSH) deficits in the pathogenesis of this disease. The aim of the present study was to test whether schizophrenia is associated with a deficit...... of GSH synthesis. Cultured skin fibroblasts from schizophrenia patients and control subjects were challenged with oxidative stress, and parameters of the rate-limiting enzyme for the GSH synthesis, the glutamate cysteine ligase (GCL), were measured. Stressed cells of patients had a 26% (P = 0.......002) decreased GCL activity as compared with controls. This reduction correlated with a 29% (P schizophrenia in two...

The influence of heroin abuse on glutathione-dependent enzymes in human brain.

Science.gov (United States)

Gutowicz, Marzena; Kaźmierczak, Beata; Barańczyk-Kuźma, Anna

2011-01-01

Heroin is an illicit narcotic abused by millions of people worldwide. In our earlier studies we have shown that heroin intoxication changes the antioxidant status in human brain. In the present work we continued our studies by estimating the effect of heroin abuse on reduced glutathione (GSH) and enzymes related to this cofactor, such as glutathione S-transferase detoxifying electrophilics (GST) and organic peroxides (as Se-independent glutathione peroxidase-GSHPx), and Se-dependent glutathione peroxidase (Se-GSHPx) specific mainly for hydrogen peroxide. Studies were conducted on human brains obtained from autopsy of 9 heroin abusers and 8 controls. The level of GSH and the activity of glutathione-related enzymes were determined spectrophotometrically. The expression of GST pi on mRNA and protein level was studied by RT-PCR and Western blotting, respectively. The results indicated significant increase of GST and GSHPx activities, unchanged Se-GSHPx activity, and decreased level of GSH in frontal, temporal, parietal and occipital cortex, brain stem, hippocampus, and white matter of heroin abusers. GST pi expression was increased on both mRNA and protein levels, however the increase was lower in brain stem than in other regions. Heroin affects all regions of human brain, and especially brain stem. Its intoxication leads to an increase of organic rather then inorganic peroxides in various brain regions. Glutathione S-transferase plays an important role during heroin intoxication, however its protective effect is lower in brain stem than in brain cortex or hippocampus. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Impaired synthesis and antioxidant defense of glutathione in the cerebellum of autistic subjects: alterations in the activities and protein expression of glutathione-related enzymes.

Science.gov (United States)

Gu, Feng; Chauhan, Ved; Chauhan, Abha

2013-12-01

Autism is a neurodevelopmental disorder associated with social deficits and behavioral abnormalities. Recent evidence in autism suggests a deficit in glutathione (GSH), a major endogenous antioxidant. It is not known whether the synthesis, consumption, and/or regeneration of GSH is affected in autism. In the cerebellum tissues from autism (n=10) and age-matched control subjects (n=10), the activities of GSH-related enzymes glutathione peroxidase (GPx), glutathione-S-transferase (GST), glutathione reductase (GR), and glutamate cysteine ligase (GCL) involved in antioxidant defense, detoxification, GSH regeneration, and synthesis, respectively, were analyzed. GCL is a rate-limiting enzyme for GSH synthesis, and the relationship between its activity and the protein expression of its catalytic subunit GCLC and its modulatory subunit GCLM was also compared between the autistic and the control groups. Results showed that the activities of GPx and GST were significantly decreased in autism compared to that of the control group (Pautistic subjects showed lower GR activity than 95% confidence interval (CI) of the control group. GCL activity was also significantly reduced by 38.7% in the autistic group compared to the control group (P=0.023), and 8 of 10 autistic subjects had values below 95% CI of the control group. The ratio of protein levels of GCLC to GCLM in the autism group was significantly higher than that of the control group (P=0.022), and GCLM protein levels were reduced by 37.3% in the autistic group compared to the control group. A positive strong correlation was observed between GCL activity and protein levels of GCLM (r=0.887) and GCLC (r=0.799) subunits in control subjects but not in autistic subjects, suggesting that regulation of GCL activity is affected in autism. These results suggest that enzymes involved in GSH homeostasis have impaired activities in the cerebellum in autism, and lower GCL activity in autism may be related to decreased protein expression

Glutathione dysregulation and the etiology and progression of human diseases.

NARCIS (Netherlands)

Ballatori, N.; Krance, S.M.; Notenboom, S.; Shi, S.; Tieu, K.; Hammond, C.L.

2009-01-01

Glutathione (GSH) plays an important role in a multitude of cellular processes, including cell differentiation, proliferation, and apoptosis, and as a result, disturbances in GSH homeostasis are implicated in the etiology and/or progression of a number of human diseases, including cancer, diseases

Different roles of glutathione in copper and zinc chelation in Brassica napus roots.

Science.gov (United States)

Zlobin, Ilya E; Kartashov, Alexander V; Shpakovski, George V

2017-09-01

We investigated the specific features of copper and zinc excess action on the roots of canola (Brassica napus L.) plants. Copper rapidly accumulated in canola root cells and reached saturation during several hours of treatment, whereas the root zinc content increased relatively slowly. Excessive copper and zinc entry inside the cell resulted in significant cell damage, as evidenced by alterations in plasmalemma permeability and decreases in cellular enzymatic activity. Zinc excess specifically damaged root hair cells, which correlated with a pronounced elevation of their labile zinc level. In vitro, we showed that reduced glutathione (GSH) readily reacted with copper ions to form complexes with blocked sulfhydryl groups. In contrast, zinc ions were ineffective as glutathione blockers, and glutathione molecules did not lose their specific chemical activity in the presence of Zn 2+ ions. The effect of copper and zinc excess on the glutathione pool in canola root cells was analysed by a combination of biochemical determination of total and oxidized glutathione contents and fluorescent staining of free reduced glutathione with monochlorobimane dye. Excess copper led to dose-dependent diminution of free reduced glutathione contents in the root cells, which could not be explained by the loss of total cellular glutathione or its oxidation. In contrast, we observed little effect of much higher intracellular zinc concentrations on the free reduced glutathione content. We concluded that GSH plays an important role in copper excess, but not zinc excess chelation, in canola root cells. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Endoplasmic reticulum transport of glutathione by Sec61 is regulated by Ero1 and Bip

DEFF Research Database (Denmark)

Ponsero, Alise J.; Igbaria, Aeid; Darch, Maxwell A.

2017-01-01

In the endoplasmic reticulum (ER), Ero1 catalyzes disulfide bond formation and promotes glutathione (GSH) oxidation to GSSG. Since GSSG cannot be reduced in the ER, maintenance of the ER glutathione redox state and levels likely depends on ER glutathione import and GSSG export. We used quantitative...... oxidation through Ero1 reductive activation, which inhibits glutathione import in a negative regulatory loop. During ER stress, transport is activated by UPR-dependent Ero1 induction, and cytosolic glutathione levels increase. Thus, the ER redox poise is tuned by reciprocal control of glutathione import...... by reduction, causing Bip oxidation and inhibition of glutathione transport. Coupling of glutathione ER import to Ero1 activation provides a basis for glutathione ER redox poise maintenance....

Novel pH control strategy for glutathione overproduction in batch ...

African Journals Online (AJOL)

The effects of pH values on cell growth and glutathione (GSH) production were studied in batch cultivation of Candida utilis. According to the fact that lower pH value favors cells growth but retards GSH production and higher pH value promotes GSH production while inhibits cells growth, a pH-shift strategy, optimized via ...

N-acetylcysteine stimulates protein synthesis in enterocytes independently of glutathione synthesis.

Science.gov (United States)

Yi, Dan; Hou, Yongqing; Wang, Lei; Long, Minhui; Hu, Shengdi; Mei, Huimin; Yan, Liqiong; Hu, Chien-An Andy; Wu, Guoyao

2016-02-01

Dietary supplementation with N-acetylcysteine (NAC) has been reported to improve intestinal health and treat gastrointestinal diseases. However, the underlying mechanisms are not fully understood. According to previous reports, NAC was thought to exert its effect through glutathione synthesis. This study tested the hypothesis that NAC enhances enterocyte growth and protein synthesis independently of cellular glutathione synthesis. Intestinal porcine epithelial cells were cultured for 3 days in Dulbecco's modified Eagle medium containing 0 or 100 μM NAC. To determine a possible role for GSH (the reduced form of glutathione) in mediating the effect of NAC on cell growth and protein synthesis, additional experiments were conducted using culture medium containing 100 μM GSH, 100 μM GSH ethyl ester (GSHee), diethylmaleate (a GSH-depletion agent; 10 μM), or a GSH-synthesis inhibitor (buthionine sulfoximine, BSO; 20 μM). NAC increased cell proliferation, GSH concentration, and protein synthesis, while inhibiting proteolysis. GSHee enhanced cell proliferation and GSH concentration without affecting protein synthesis but inhibited proteolysis. Conversely, BSO or diethylmaleate reduced cell proliferation and GSH concentration without affecting protein synthesis, while promoting protein degradation. At the signaling level, NAC augmented the protein abundance of total mTOR, phosphorylated mTOR, and phosphorylated 70S6 kinase as well as mRNA levels for mTOR and p70S6 kinase in IPEC-1 cells. Collectively, these results indicate that NAC upregulates expression of mTOR signaling proteins to stimulate protein synthesis in enterocytes independently of GSH generation. Our findings provide a hitherto unrecognized biochemical mechanism for beneficial effects of NAC in intestinal cells.

A new role for glutathione in the regulation of root architecture linked to strigolactones.

Science.gov (United States)

Marquez-Garcia, Belen; Njo, Maria; Beeckman, Tom; Goormachtig, Sofie; Foyer, Christine H

2014-02-01

Reduced glutathione (GSH) is required for root development, but its functions are not characterized. The effects of GSH depletion on root development were therefore studied in relation to auxin and strigolactone (SL) signalling using a combination of molecular genetic approaches and pharmacological techniques. Lateral root (LR) density was significantly decreased in GSH synthesis mutants (cad2-1, pad2-, rax1-), but not by the GSH synthesis inhibitor, buthionine sulfoximine (BSO). BSO-induced GSH depletion therefore did not influence root architecture in the same way as genetic impairment. Root glutathione contents were similar in the wild-type seedlings and max3-9 and max4-1 mutants that are deficient in SL synthesis and in the SL-signalling mutant, max2-1. BSO-dependent inhibition of GSH synthesis depleted the tissue GSH pool to a similar extent in the wild-type and SL synthesis mutants, with no effect on LR density. The application of the SL analogue GR24 increased root glutathione in the wild-type, max3-9 and max4-1 seedlings, but this increase was absent from max2-1. Taken together, these data establish a link between SLs and the GSH pool that occurs in a MAX2-dependent manner. © 2013 John Wiley & Sons Ltd.

Glutathione synthesis and homeostasis in isolated type II alveolar cells

International Nuclear Information System (INIS)

Saito, K.; Warshaw, J.B.; Prough, R.A.

1986-01-01

After isolation of Type II cells from neonatal rat lung, the glutathione (GSH) levels in these cells were greatly depressed. The total glutathione content could be increased 5-fold within 12-24 h by incubating the cells in media containing sulfur amino acids. Similarly, the activity of γ-glutamyltranspeptidase was low immediately after isolation, but was increased 2-fold during the first 24 h culture. Addition of either GSH or GSSG to the culture media increased the GSH content of Type II cells 2-2.5-fold. Buthionine sulfoximine and NaF prevented this replenishment of GSH during 24 h culture. When the rates of de novo synthesis of GSH and GSSG from 35 S-cysteine were measured, the amounts of newly formed GSH decreased to 80% in the presence of GSH or GSSG. This suggests that exogenous GSH/GSSG can be taken up by the Type II cells to replenish the intracellular pool of GSH. Methionine was not as effective as cysteine in the synthesis of GSH. These results suggest that GSH levels in the isolated Type II cell can be maintained by de novo synthesis or uptake of exogenous GSH. Most of the GSH synthesized from cysteine, however, was excreted into the media of the cultured cells indicative of a potential role for the type II cell in export of the non-protein thiol

Increased biliary excretion of glutathione is generated by the glutathione-dependent hepatobiliary transport of antimony and bismuth.

Science.gov (United States)

Gyurasics, A; Koszorús, L; Varga, F; Gregus, Z

1992-10-06

We have recently demonstrated that the hepatobiliary transport of arsenic is glutathione-dependent and is associated with a profound increase in biliary excretion of glutathione (GSH), hepatic GSH depletion and diminished GSH conjugation (Gyurasics A, Varga F and Gregus Z, Biochem Pharmacol 41: 937-944 and Gyurasics A, Varga F and Gregus Z, Biochem Pharmacol 42: 465-468, 1991). The present studies in rats aimed to determine whether antimony and bismuth, other metalloids in group Va of the periodic table, also possess similar properties. Antimony potassium tartrate (25-100 mumol/kg, i.v.) and bismuth ammonium citrate (50-200 mumol/kg, i.v.) increased up to 50- and 4-fold, respectively, the biliary excretion of non-protein thiols (NPSH). This resulted mainly from increased hepatobiliary transport of GSH as suggested by a close parallelism in the biliary excretion of NPSH and GSH after antimony or bismuth administration. Within 2 hr, rats excreted into bile 55 and 3% of the dose of antimony (50 mumol/kg, i.v.) and bismuth (150 mumol/kg, i.v.), respectively. The time courses of the biliary excretion of these metalloids and NPSH or GSH were strikingly similar suggesting co-ordinate hepatobiliary transport of the metalloids and GSH. However, at the peak of their excretion, each molecule of antimony or bismuth resulted in a co-transport of approximately three molecules of GSH. Diethyl maleate, indocyanine green and sulfobromophthalein (BSP), which decreased biliary excretion of GSH, significantly diminished excretion of antimony and bismuth into bile indicating that hepatobiliary transport of these metalloids is GSH-dependent. Administration of antimony, but not bismuth, decreased hepatic GSH level by 30% and reduced the GSH conjugation and biliary excretion of BSP. These studies demonstrate that the hepatobiliary transport of trivalent antimony and bismuth is GSH-dependent similarly to the hepatobiliary transport of trivalent arsenic. Proportionally to their biliary

Activation of the microsomal glutathione-S-transferase and reduction of the glutathione dependent protection against lipid peroxidation by acrolein

NARCIS (Netherlands)

Haenen, G R; Vermeulen, N P; Tai Tin Tsoi, J N; Ragetli, H M; Timmerman, H; Blast, A

1988-01-01

Allyl alcohol is hepatotoxic. It is generally believed that acrolein, generated out of allyl alcohol by cytosolic alcohol dehydrogenase, is responsible for this toxicity. The effect of acrolein in vitro and in vivo on the glutathione (GSH) dependent protection of liver microsomes against lipid

Glutathione, Glutaredoxins, and Iron.

Science.gov (United States)

Berndt, Carsten; Lillig, Christopher Horst

2017-11-20

Glutathione (GSH) is the most abundant cellular low-molecular-weight thiol in the majority of organisms in all kingdoms of life. Therefore, functions of GSH and disturbed regulation of its concentration are associated with numerous physiological and pathological situations. Recent Advances: The function of GSH as redox buffer or antioxidant is increasingly being questioned. New functions, especially functions connected to the cellular iron homeostasis, were elucidated. Via the formation of iron complexes, GSH is an important player in all aspects of iron metabolism: sensing and regulation of iron levels, iron trafficking, and biosynthesis of iron cofactors. The variety of GSH coordinated iron complexes and their functions with a special focus on FeS-glutaredoxins are summarized in this review. Interestingly, GSH analogues that function as major low-molecular-weight thiols in organisms lacking GSH resemble the functions in iron homeostasis. Since these iron-related functions are most likely also connected to thiol redox chemistry, it is difficult to distinguish between mechanisms related to either redox or iron metabolisms. The ability of GSH to coordinate iron in different complexes with or without proteins needs further investigation. The discovery of new Fe-GSH complexes and their physiological functions will significantly advance our understanding of cellular iron homeostasis. Antioxid. Redox Signal. 27, 1235-1251.

Isolation of glutathione-deficient mutants of the yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Kistler, M.; Eckardt, F.; Summer, K.-H.

1986-01-01

Glutathione-deficient (gsh - ) mutants of the yeast Saccharomyces cerevisiae were isolated after UV treatment using MNNG as selective agent. For genetic and biochemical characterization 5 mutant strains were chosen which exhibited considerably decreased residual GSH contents varying from 2 to 6% of the wild-type levels. All 5 isolates showed a 2:2 segregation of the gsh - :GSH + phenotypes alluding to a monogenic recessive mutation. Complementation analysis indicates that all gsh - mutants belong to one complementation group. (Auth.)

Glutathione attenuates uranyl toxicity in Lactococcus lactis

International Nuclear Information System (INIS)

Fahmy, Karim; Oertel, Jana; Solioz, M.

2017-01-01

We investigated the role of intracellular glutathione (GSH), which in a large number of taxa plays a role in the protection against the toxicity of heavy metals. Anaerobically grown Lactococcus lactis containing an inducible GSH synthesis pathway was used as a model organism allowing the study of GSH-dependent uranyl detoxification without interference from additional reactive oxygen species. Microcalorimetric measurements of the metabolic heat showed that intracellular GSH attenuates the toxicity of uranium at a concentration in the range of 10-150 μM. Isothermal titration calorimetry revealed the endothermic binding of U(VI) to the carboxyl group(s) of GSH. The data indicate that the primary detoxifying mechanism is the intracellular sequestration of carboxyl-coordinated U(VI) into an insoluble complex with GSH.

Glutathione attenuates uranyl toxicity in Lactococcus lactis

Energy Technology Data Exchange (ETDEWEB)

Fahmy, Karim; Oertel, Jana [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biophysics; Obeid, M. [Technische Univ. Dresden (Germany); Solioz, M. [Bern Univ. (Switzerland)

2017-06-01

We investigated the role of intracellular glutathione (GSH), which in a large number of taxa plays a role in the protection against the toxicity of heavy metals. Anaerobically grown Lactococcus lactis containing an inducible GSH synthesis pathway was used as a model organism allowing the study of GSH-dependent uranyl detoxification without interference from additional reactive oxygen species. Microcalorimetric measurements of the metabolic heat showed that intracellular GSH attenuates the toxicity of uranium at a concentration in the range of 10-150 μM. Isothermal titration calorimetry revealed the endothermic binding of U(VI) to the carboxyl group(s) of GSH. The data indicate that the primary detoxifying mechanism is the intracellular sequestration of carboxyl-coordinated U(VI) into an insoluble complex with GSH.

Role of glutathione in affecting the radiosensitivity of molecular and cellular systems

International Nuclear Information System (INIS)

Simone, G.; Tamba, M.; Quintiliani, M.

1983-01-01

It has previously been shown that radioinduced organic radicals can be repaired by hydrogen donation from glutathione (GSH) and this repair is in competition with oxygen (damage fixation). In this paper the influence of exogenous glutathione on the radiation response of the enzyme alcoholdehydrogenase (YADH), DNA in vitro, and E. coli B/r cells has been investigated. GSH is observed to protect YADH essentially by free radical scavenging mechanisms in both presence or absence of oxygen. The same mechanism seems operate in the radioprotection afforded by GSH to DNA in vitro. E. coli B/r cells are protected at higher extent by GSH than its oxidized form (GSSG); the possibility that GSH penetrate into bacterial cells more easily that GSSG can explain their different behaviour. None of the three systems studied has provided definitive support for the occurrence of the hydrogen donation reaction in the radioprotective mechanisms of GSH versus biomolecules and bacterial cells. (orig.)

Effect of an aqueous extract of Cucurbita ficifolia Bouché on the glutathione redox cycle in mice with STZ-induced diabetes.

Science.gov (United States)

Díaz-Flores, M; Angeles-Mejia, S; Baiza-Gutman, L A; Medina-Navarro, R; Hernández-Saavedra, D; Ortega-Camarillo, C; Roman-Ramos, R; Cruz, M; Alarcon-Aguilar, F J

2012-10-31

Cucurbita ficifolia is used in Mexican traditional medicine as an anti-diabetic and anti-inflammatory agent and its actions can be mediated by antioxidant mechanisms. Disturbance in the homeostasis of glutathione has been implicated in the etiology and progression of diabetes mellitus and its complications. It was evaluated, the effect of an aqueous extract of Cucurbita ficifolia on glycemia, plasma lipid peroxidation; as well as levels of reduced (GSH) and oxidized (GSSG) glutathione and activities of enzymes involved in glutathione redox cycle: glutathione peroxidase (GPx) and glutathione reductase (GR) in liver, pancreas, kidney and heart homogenates of streptozotocin-induced diabetic mice. Increased blood glucose and lipid peroxidation, together with decreased of GSH concentration, GSH/GSSG ratio and its redox potential (E(h)), and enhanced activity of GPx and GR in liver, pancreas and kidney were the salient features observed in diabetic mice. Administration of the aqueous extract of Cucurbita ficifolia to diabetic mice for 30 days, used at a dose of 200 mg/kg, resulted in a significant reduction in glycemia, polydipsia, hyperphagia and plasma lipid peroxidation. Moreover, GSH was increased in liver, pancreas and kidney, and GSSG was reduced in liver, pancreas and heart, therefore GSH/GSSG ratio and its E(h) were restored. Also, the activities involved in the glutathione cycle were decreased, reaching similar values to controls. An aqueous extract of Cucurbita ficifolia with hypoglycemic action, improve GSH redox state, increasing glutathione pool, GSH, GSH/GSSG ratio and its E(h), mechanism that can explain, at least in part, its antioxidant properties, supporting its use as an alternative treatment for the control of diabetes mellitus, and prevent the induction of complications by oxidative stress. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Sulfate and glutathione enhanced arsenic accumulation by arsenic hyperaccumulator Pteris vittata L

International Nuclear Information System (INIS)

Wei Shuhe; Ma, Lena Q.; Saha, Uttam; Mathews, Shiny; Sundaram, Sabarinath; Rathinasabapathi, Bala; Zhou Qixing

2010-01-01

This experiment examined the effects of sulfate (S) and reduced glutathione (GSH) on arsenic uptake by arsenic hyperaccumulator Pteris vittata after exposing to arsenate (0, 15 or 30 mg As L -1 ) with sulfate (6.4, 12.8 or 25.6 mg S L -1 ) or GSH (0, 0.4 or 0.8 mM) for 2-wk. Total arsenic, S and GSH concentrations in plant biomass and arsenic speciation in the growth media and plant biomass were determined. While both S (18-85%) and GSH (77-89%) significantly increased arsenic uptake in P. vittata, GSH also increased arsenic translocation by 61-85% at 0.4 mM (p < 0.05). Sulfate and GSH did not impact plant biomass or arsenic speciation in the media and biomass. The S-induced arsenic accumulation by P. vittata was partially attributed to increased plant GSH (21-31%), an important non-enzymatic antioxidant countering oxidative stress. This experiment demonstrated that S and GSH can effectively enhance arsenic uptake and translocation by P. vittata. - Sulfate and glutathione increased arsenic uptake and translocation in Pteris vittata.

Glutathione-mediated detoxification of halobenzoquinone drinking water disinfection byproducts in T24 cells.

Science.gov (United States)

Li, Jinhua; Wang, Wei; Zhang, Hongquan; Le, X Chris; Li, Xing-Fang

2014-10-01

Halobenzoquinones (HBQs) are a new class of drinking water disinfection byproducts (DBPs) and are capable of producing reactive oxygen species and causing oxidative damage to proteins and DNA in T24 human bladder carcinoma cells. However, the exact mechanism of the cytotoxicity of HBQs is unknown. Here, we investigated the role of glutathione (GSH) and GSH-related enzymes including glutathione S-transferase (GST) and glutathione peroxidase (GPx) in defense against HBQ-induced cytotoxicity in T24 cells. The HBQs are 2,6-dichloro-1,4-benzoquinone (DCBQ), 2,6-dichloro-3-methyl-1,4-benzoquinone (DCMBQ), 2,3,6-trichloro-1,4-benzoquinone (TriCBQ), and 2,6-dibromobenzoquinone (DBBQ). We found that depletion of cellular GSH could sensitize cells to HBQs and extracellular GSH supplementation could attenuate HBQ-induced cytotoxicity. HBQs caused significant cellular GSH depletion and increased cellular GST activities in a concentration-dependent manner. Our mass spectrometry study confirms that HBQs can conjugate with GSH, explaining in part the mechanism of GSH depletion by HBQs. The effects of HBQs on GPx activity are compound dependent; DCMBQ and DBBQ decrease cellular GPx activities, whereas DCBQ and TriCBQ have no significant effects. Pearson correlation analysis shows that the cellular GSH level is inversely correlated with ROS production and cellular GST activity in HBQ-treated cells. These results support a GSH and GSH-related enzyme-mediated detoxification mechanism of HBQs in T24 cells. © The Author 2014. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Glutathione and Mitochondria

Directory of Open Access Journals (Sweden)

Vicent eRibas

2014-07-01

Full Text Available Glutathione (GSH is the main nonprotein thiol in cells whose functions are dependent on the redox-active thiol of its cysteine moiety that serves as a cofactor for a number of antioxidant and detoxifying enzymes. While synthesized exclusively in the cytosol from its constituent amino acids, GSH is distributed in different compartments, including mitochondria where its concentration in the matrix equals that of the cytosol. This feature and its negative charge at physiological pH imply the existence of specific carriers to import GSH from the cytosol to the mitochondrial matrix, where it plays a key role in defense against respiration-induced reactive oxygen species and in the detoxification of lipid hydroperoxides and electrophiles. Moreover, as mitochondria play a central strategic role in the activation and mode of cell death, mitochondrial GSH has been shown to critically regulate the level of sensitization to secondary hits that induce mitochondrial membrane permeabilization and release of proteins confined in the intermembrane space that once in the cytosol engage the molecular machinery of cell death. In this review, we summarize recent data on the regulation of mitochondrial GSH and its role in cell death and prevalent human diseases, such as cancer, fatty liver disease and Alzheimer’s disease.

Glutathione in Cancer Cell Death

Energy Technology Data Exchange (ETDEWEB)

Ortega, Angel L. [Department of Physiology, Faculty of Medicine and Odontology, University of Valencia, 17 Av. Blasco Ibanez, 46010 Valencia (Spain); Mena, Salvador [Green Molecular SL, Pol. Ind. La Coma-Parc Cientific, 46190 Paterna, Valencia (Spain); Estrela, Jose M., E-mail: jose.m.estrela@uv.es [Department of Physiology, Faculty of Medicine and Odontology, University of Valencia, 17 Av. Blasco Ibanez, 46010 Valencia (Spain)

2011-03-11

Glutathione (L-γ-glutamyl-L-cysteinyl-glycine; GSH) in cancer cells is particularly relevant in the regulation of carcinogenic mechanisms; sensitivity against cytotoxic drugs, ionizing radiations, and some cytokines; DNA synthesis; and cell proliferation and death. The intracellular thiol redox state (controlled by GSH) is one of the endogenous effectors involved in regulating the mitochondrial permeability transition pore complex and, in consequence, thiol oxidation can be a causal factor in the mitochondrion-based mechanism that leads to cell death. Nevertheless GSH depletion is a common feature not only of apoptosis but also of other types of cell death. Indeed rates of GSH synthesis and fluxes regulate its levels in cellular compartments, and potentially influence switches among different mechanisms of death. How changes in gene expression, post-translational modifications of proteins, and signaling cascades are implicated will be discussed. Furthermore, this review will finally analyze whether GSH depletion may facilitate cancer cell death under in vivo conditions, and how this can be applied to cancer therapy.

Behaviour of glutathione in the cornea epithelium of cattle and rabbits under the influence of infrared radiation

International Nuclear Information System (INIS)

Scharsich, G.

1978-01-01

After creating a keratitis photoelectrica by means of a mercury/quartz analysis lamp, the concentration of GSH (glutathion, reduced) and GSSG (glutathion, oxidised) in the cornea epithelium of cattle and of rabbits at different times after irradiation was determined. The question of whether ultraviolet radiation considerably influences the GSH/GSSG quotient before the keratitis photoelectrica is fully formed morphologically, could be answered as follows: There is no considerable change in the GSH/GSSG quotient during the first 7-10 hours after the irradiation. Then, when there is, also morphologically, a keratitis photoelectrica, the GSH/GSSG quotient is doubled. The linkage of the GSH/GSSG system and hexosephosphatshunt via the NADP/NADPH system leads us to the conclusion that irradiation does not cause any direct changes in the GSH/GSSG system. Only when the cornea epithelium visably disintegrates an increased reduction of the glutathion occurs, like in several other damaging influences. Thus the found increase of the GSH/GSSG quotient 7-10 hours after ultraviolet irradiation might be unspecific. (orig./AJ) [de

Expression of the glutathione enzyme system of human colon mucosa by localisation, gender and age.

NARCIS (Netherlands)

Hoensch, H.; Peters, W.H.M.; Roelofs, H.M.J.; Kirch, W.

2006-01-01

BACKGROUND: The glutathione S-transferases (GST) can metabolise endogenous and exogenous toxins and carcinogens by catalysing the conjugation of diverse electrophiles with reduced glutathione (GSH). Variations of GST enzyme activity could influence the susceptibility of developing cancers in certain

Efficacy of free glutathione and niosomal glutathione in the treatment of acetaminophen-induced hepatotoxicity in cats

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L.A. Denzoin Vulcano

2013-06-01

Full Text Available Acetaminophen (APAP administration results in hepatotoxicity and hematotoxicity in cats. The response to three different treatments against APAP poisoning was evaluated. Free glutathione (GSH (200mg/kg, niosomal GSH (14 mg/kg and free amino acids (180 mg/kg of N-acetylcysteine and 280 mg/kg of methionine were administered to cats that were intoxicated with APAP (a single dose of 150 mg/kg, p.o.. Serum concentration of alanine aminotransferase (ALT along with serum, liver and erythrocyte concentration of GSH and methemoglobin percentage were measured before and 4, 24 and 72 hours after APAP administration. Free GSH (200 mg/kg and niosomal GSH (14 mg/kg were effective in reducing hepatotoxicity and hematotoxicity in cats intoxicated with a dose of 150 mg/kg APAP. We conclude that both types of treatments can protect the liver and haemoglobin against oxidative stress in APAP intoxicated cats. Furthermore, our results showed that treatment with niosomal GSH represents an effective therapeutic approach for APAP poisoning.

Radiobiological studies with a series of human cell lines of varying glutathione content

Energy Technology Data Exchange (ETDEWEB)

Astor, M.B. (Columbia Univ., New York (USA). Radiological Research Lab.)

1984-08-01

The effect of decreased levels of intracellular glutathione (GSH) on the radiosensitivity of aerated and hypoxic cells was studied using human skin fibroblasts obtained from patients affected with the inborn error of metabolism, 5-oxoprolinuria. The oxygen enhancement ratios (OER) were determined for four cell lines obtained from a single family, SR and SUR (heterozygous parents) and GM3877 and GM3878 (affected homozygous siblings). Glutathione values ranged from 7.4 to 130% of control values. Only GM3877 with a GSH value 7.4% of control exhibited a reduced OER of 1.9 compared with a control value of 3. These results suggest that a reduction in OER is observed only when GSH levels reach extremely low values.

Effects of mercury and selenium on glutathione metabolism and oxidative stress in mallard ducks

Science.gov (United States)

Hoffman, D.J.; Heinz, G.H.

1998-01-01

Earlier studies reported on the toxicity and related oxidative stress of different forms of Se, including seleno-D,L-methionine, in mallards (Anas platyrhynchos). This study compares the effects of Se (seleno-D,L-methionine) and Hg (methylmercury chloride) separately and in combination. Mallard drakes received one of the following diets: untreated feed (controls), or feed containing 10 ppm Se, 10 ppm Hg, or 10 ppm Se in combination with 10 ppm Hg. After 10 weeks, blood, liver, and brain samples were collected for biochemical assays. The following clinical and biochemical alterations occurred in response to mercury exposure: hematocrit and hemoglobin concentrations decreased; activities of the enzymes glutathione (GSH) peroxidase (plasma and liver), glutathione-S-transferase (liver), and glucose-6-phosphate dehydrogenase (G-6-PDH) (liver and brain) decreased; hepatic oxidized glutathione (GSSG) concentration increased relative to reduced glutathione (GSH); and lipid peroxidation in the brain was evident as detected by increased thiobarbituric reactive substances (TBARS). Effects of Se alone included increased hepatic GSSG reductase activity and brain TBARS concentration. Se in combination with Hg partially or totally alleviated effects of Hg on GSH peroxidase, G-6-PDH, and GSSG. These findings are compared in relation to field observations for diving ducks and other aquatic birds. It is concluded that since both Hg and excess Se can affect thiol status, measurement of associated enzymes in conjunction with thiol status may be a useful bioindicator to discriminate between Hg and Se effects. The ability of Se to restore the activities of G-6-PDH, GSH peroxidase, and glutathione status involved in antioxidative defense mechanisms may be crucial to biological protection from the toxic effects of methyl mercury.

Is Glutathione the Major Cellular Target of Cisplatin?

DEFF Research Database (Denmark)

Kasherman, Yonit; Stürup, Stefan; gibson, dan

2009-01-01

Cisplatin is an anticancer drug whose efficacy is limited because tumors develop resistance to the drug. Resistant cells often have elevated levels of cellular glutathione (GSH), believed to be the major cellular target of cisplatin that inactivates the drug by binding to it irreversibly, forming...

Misonidazole-glutathione conjugates in CHO cells

International Nuclear Information System (INIS)

Varghese, A.J.; Whitmore, G.F.

1984-01-01

Misonidazole, after reduction to the hydroxylamine derivative, reacts with glutathione (GSH) under physiological conditions. The reaction product has been identified as a mixture of two isomeric conjugates. When water soluble extracts of CHO cells exposed to misonidazole under hypoxic conditions are subjected to HPLC analysis, misonidazole derivatives, having the same chromatographic properties as the GSH-MISO conjugates, were detected. When CHO cells were incubated with misonidazole in the presence of added GSH, a substantial increase in the amount of the conjugate was detected. When extracts of CHO cells exposed to misonidazole under hypoxia were subsequently exposed to GSH, an increased formation of the conjugate was observed. A rearrangement product of the hydroxylamine derivative of misonidazole is postulated as the reactive intermediate responsible for the formation of the conjugate

Effect of supplementation with methionine and different fat sources on the glutathione redox system of growing chickens.

Science.gov (United States)

Németh, Katalin; Mézes, M; Gaál, T; Bartos, A; Balogh, K; Husvéth, F

2004-01-01

The effect of supplementary methionine and fats of different saturation levels on the glutathione redox system of growing broiler cockerels was studied. The diet of three groups of chicks was supplemented with corn germ oil, beef tallow and fish oil at the levels of 30 g/kg and 50 g/kg of feed, respectively. The diet of further three groups was supplemented with methionine (5 g/kg of feed) in addition to the different fat sources. Control chicks were fed with a compound feed without methionine and fat supplementation. Reduced glutathione (GSH) and glutathione disulphide (GSSG) content as well as glutathione peroxidase activity in the liver were determined and GSH/GSSG ratio was calculated at day old and then at one and three weeks of age. Our results indicate that supplementary methionine stimulates both the synthesis of the glutathione redox system and glutathione peroxidase activity in growing chickens in the first period of postnatal life, when the risk of lipid peroxidation is high due to feeding unsaturated fats in the diet.

Glutathione--hydroxyl radical interaction: a theoretical study on radical recognition process.

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Béla Fiser

Full Text Available Non-reactive, comparative (2 × 1.2 μs molecular dynamics simulations were carried out to characterize the interactions between glutathione (GSH, host molecule and hydroxyl radical (OH(•, guest molecule. From this analysis, two distinct steps were identified in the recognition process of hydroxyl radical by glutathione: catching and steering, based on the interactions between the host-guest molecules. Over 78% of all interactions are related to the catching mechanism via complex formation between anionic carboxyl groups and the OH radical, hence both terminal residues of GSH serve as recognition sites. The glycine residue has an additional role in the recognition of OH radical, namely the steering. The flexibility of the Gly residue enables the formation of further interactions of other parts of glutathione (e.g. thiol, α- and β-carbons with the lone electron pair of the hydroxyl radical. Moreover, quantum chemical calculations were carried out on selected GSH/OH(• complexes and on appropriate GSH conformers to describe the energy profile of the recognition process. The relative enthalpy and the free energy changes of the radical recognition of the strongest complexes varied from -42.4 to -27.8 kJ/mol and from -21.3 to 9.8 kJ/mol, respectively. These complexes, containing two or more intermolecular interactions, would be the starting configurations for the hydrogen atom migration to quench the hydroxyl radical via different reaction channels.

Metabolic modulation of glutathione in whole blood components ...

African Journals Online (AJOL)

use

2011-12-05

Dec 5, 2011 ... Key words: Lead acetate, glutathione (GSH), dithiobisdinitrobenzoic acid (DTNB), plasma and cytosolic ... fraction. Control containing 1 ml of venous blood and 1 ml of 0.9%. NaCl solution was also centrifuged for isolation of plasma. The packed cells were .... altered fatty acid composition of membranes?

Radiobiological studies with a series of human cell lines of varying glutathione content

International Nuclear Information System (INIS)

Astor, M.B.

1984-01-01

The effect of decreased levels of intracellular glutathione (GSH) on the radiosensitivity of aerated and hypoxic cells was studied using human skin fibroblasts obtained from patients affected with the inborn error of metabolism, 5-oxoprolinuria. The oxygen enhancement ratios (OER) were determined for four cell lines obtained from a single family, SR and SUR (heterozygous parents) and GM3877 and GM3878 (affected homozygous siblings). Glutathione values ranged from 7.4 to 130% of control values. Only GM3877 with a GSH value 7.4% of control exhibited a reduced OER of 1.9 compared with a control value of 3. These results suggest that a reduction in OER is observed only when GSH levels reach extremely low values. (author)

Glutathione depletion in tissues after administration of buthionine sulphoximine

International Nuclear Information System (INIS)

Minchinton, A.I.; Rojas, A.; Smith, A.; Soranson, J.A.; Shrieve, D.C.; Jones, N.R.; Bremner, J.C.

1984-01-01

Buthionine sulphoximine (BSO) an inhibitor of glutathione (GSH) biosynthesis, was administered to mice in single and repeated doses. The resultant pattern of GSH depletion was studied in liver, kidney, skeletal muscle and three types of murine tumor. Liver and kidney exhibited a rapid depletion of GSH. Muscle was depleted to a similar level, but at a slower rate after a single dose. All three tumors required repeated administration of BSO over several days to obtain a similar degree of depletion to that shown in the other tissues

Role of glutathione biosynthesis in endothelial dysfunction and fibrosis

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Cristina Espinosa-Díez

2018-04-01

Full Text Available Glutathione (GSH biosynthesis is essential for cellular redox homeostasis and antioxidant defense. The rate-limiting step requires glutamate-cysteine ligase (GCL, which is composed of the catalytic (GCLc and the modulatory (GCLm subunits. To evaluate the contribution of GCLc to endothelial function we generated an endothelial-specific Gclc haplo-insufficient mouse model (Gclc e/+ mice. In murine lung endothelial cells (MLEC derived from these mice we observed a 50% reduction in GCLc levels compared to lung fibroblasts from the same mice. MLEC obtained from haplo-insufficient mice showed significant reduction in GSH levels as well as increased basal and stimulated ROS levels, reduced phosphorylation of eNOS (Ser 1177 and increased eNOS S-glutathionylation, compared to MLEC from wild type (WT mice. Studies in mesenteric arteries demonstrated impaired endothelium-dependent vasodilation in Gclc(e/+ male mice, which was corrected by pre-incubation with GSH-ethyl-ester and BH4. To study the contribution of endothelial GSH synthesis to renal fibrosis we employed the unilateral ureteral obstruction model in WT and Gclc(e/+ mice. We observed that obstructed kidneys from Gclc(e/+ mice exhibited increased deposition of fibrotic markers and reduced Nrf2 levels. We conclude that the preservation of endothelial GSH biosynthesis is not only critical for endothelial function but also in anti-fibrotic responses. Keywords: Glutamate-cysteine ligase, ROS, Glutathione, Endothelial dysfunction, Kidney Fibrosis

Comparative study of biological activity of glutathione, sodium ...

African Journals Online (AJOL)

Glutathione (GSH) and sodium tungstate (Na2WO4) are important pharmacological agents. They provide protection to cells against cytotoxic agents and thus reduce their cytotoxicity. It was of interest to study the biological activity of these two pharmacological active agents. Different strains of bacteria were used and the ...

Protection of myocytes against free radical-induced damage by accelerated turnover of the glutathione redox cycle

NARCIS (Netherlands)

Le, C. T.; Hollaar, L.; van der Valk, E. J.; Franken, N. A.; van Ravels, F. J.; Wondergem, J.; van der Laarse, A.

1995-01-01

The primary defence mechanism of myocytes against peroxides and peroxide-derived peroxyl and alkoxyl radicals is the glutathione redox cycle. The purpose of the present study was to increase the turnover rate of this cycle by stimulating the glutathione peroxidase catalysed reaction (2GSH-->GSSG),

Glutathione in the modulation of radiosensitivity: a review

International Nuclear Information System (INIS)

Umadevi, P.; Prasanna, P.G.S.

1993-01-01

Glutathione (γ - glutamyl cysteinyl glycine, GSH) constitutes the major low molecular weight thiol compound in the mammalian cells. GSH has been assigned an important role in determining the inherent radiosensitivity of cells. Endogenous GSH involved in a number of radiation induced chemical processes, which help in the repair of radiation injury to the target molecules. Experimental evidence suggests that GSH competes with molecular oxygen in the cells to prevent fixation of DNA damage. Certain chemicals like buthionine sulfoximine are found to deplete the cellular GSH content by interactions at specific sites in the GSH cycle. It may be possible to take advantage of this phenomenon by increasing the radiosensitivity of hypoxic tumor cells, without seriously affecting the normal cells, so as to increase the therapeutic efficiency of radiation treatment. (author). 52 refs., 1 fig

Metabolic modulation of glutathione in whole blood components ...

African Journals Online (AJOL)

Lead has been found to have the ability to interfere in the metabolism and biological activities of many proteins. It has also been found that metalloelements have strong affinity for sulfhydryl (-SH) groups in biological molecules including glutathione (GSH) in tissues. Because of these facts, it was of interest to investigate ...

Catalysis of Silver catfish Major Hepatic Glutathione Transferase proceeds via rapid equilibrium sequential random Mechanism

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Ayodele O. Kolawole

Full Text Available Fish hepatic glutathione transferases are connected with the elimination of intracellular pollutants and detoxification of organic micro-pollutants in their aquatic ecosystem. The two-substrate steady state kinetic mechanism of Silver catfish (Synodontis eupterus major hepatic glutathione transferases purified to apparent homogeneity was explored. The enzyme was dimeric enzyme with a monomeric size of 25.6 kDa. Initial-velocity studies and Product inhibition patterns by methyl glutathione and chloride with respect to GSH-CDNB; GSH-ρ-nitrophenylacetate; and GSH-Ethacrynic acid all conforms to a rapid equilibrium sequential random Bi Bi kinetic mechanism rather than steady state sequential random Bi Bi kinetic. α was 2.96 ± 0.35 for the model. The pH profile of Vmax/KM (with saturating 1-chloro-2,4-dinitrobenzene and variable GSH concentrations showed apparent pKa value of 6.88 and 9.86. Inhibition studies as a function of inhibitor concentration show that the enzyme is a homodimer and near neutral GST. The enzyme poorly conjugates 4-hydroxylnonenal and cumene hydroperoxide and may not be involved in oxidative stress protection. The seGST is unique and overwhelmingly shows characteristics similar to those of homodimeric class Pi GSTs, as was indicated by its kinetic mechanism, substrate specificity and inhibition studies. The rate- limiting step, probably the product release, of the reaction is viscosity-dependent and is consequential if macro-viscosogen or micro-viscosogen. Keywords: Silver catfish, Glutathione transferase, Steady-state, Kinetic mechanism, Inhibition

Functional identification of glutamate cysteine ligase and glutathione synthetase in the marine yeast Rhodosporidium diobovatum

Science.gov (United States)

Kong, Min; Wang, Fengjuan; Tian, Liuying; Tang, Hui; Zhang, Liping

2018-02-01

Glutathione (GSH) fulfills a variety of metabolic functions, participates in oxidative stress response, and defends against toxic actions of heavy metals and xenobiotics. In this study, GSH was detected in Rhodosporidium diobovatum by high-performance liquid chromatography (HPLC). Then, two novel enzymes from R. diobovatum were characterized that convert glutamate, cysteine, and glycine into GSH. Based on reverse transcription PCR, we obtained the glutathione synthetase gene ( GSH2), 1866 bp, coding for a 56.6-kDa protein, and the glutamate cysteine ligase gene ( GSH1), 2469 bp, coding for a 90.5-kDa protein. The role of GSH1 and GSH2 for the biosynthesis of GSH in the marine yeast R. diobovatum was determined by deletions using the CRISPR-Cas9 nuclease system and enzymatic activity. These results also showed that GSH1 and GSH2 were involved in the production of GSH and are thus being potentially useful to engineer GSH pathways. Alternatively, pET- GSH constructed using vitro recombination could be used to detect the function of genes related to GSH biosynthesis. Finally, the fermentation parameters determined in the present study provide a reference for industrial GSH production in R. diobovatum.

Decrease in glutathione content in boar sperm after cryopreservation. Effect of the addition of reduced glutathione to the freezing and thawing extenders.

Science.gov (United States)

Gadea, Joaquín; Sellés, Elena; Marco, Marco Antonio; Coy, Pilar; Matás, Carmen; Romar, Raquel; Ruiz, Salvador

2004-08-01

Although glutathione content in boar spermatozoa has been previously reported, the effect of reduced glutathione (GSH) on semen parameters and the fertilizing ability of boar spermatozoa after cryopreservation has never been evaluated. In this study, GSH content was determined in ejaculated boar spermatozoa before and after cryopreservation. Semen samples were centrifuged and GSH content in the resulting pellet monitored spectrophotometrically. The fertilizing ability of frozen-thawed boar sperm was also tested in vitro by incubating sperm with in vitro matured oocytes obtained from gilts. GSH content in fresh semen was 3.84 +/- 0.21 nM GSH/10(8) sperm. Following semen cryopreservation, there was a 32% decrease in GSH content (P boars and after various preservation protocols (P = 0.0102 ). The effect of addition of GSH to the freezing and thawing extenders was also evaluated. Addition of 5 mM GSH to the freezing extender did not have a significant effect on standard semen parameters or sperm fertilizing ability after thawing. In contrast, when GSH was added to the thawing extender, a dose-dependent tendency to increase in sperm fertilizing ability was observed, although no differences were observed in standard semen parameters. In summary, (i) there was a loss in GSH content after cryopreservation of boar semen; (ii) addition of GSH to the freezing extender did not result in any improvement in either standard semen parameters or sperm fertilizing ability; and (iii) addition of GSH to the thawing extender resulted in a significant increase in sperm fertilizing ability. Nevertheless, future studies must conclude if this is the case for all boars. Furthermore, since addition of GSH to the thawing extender did not result in an improvement in standard semen parameters, this suggests that during the thawing process, GSH prevents damage of a sperm property that is critical in the fertilization process but that is not measured in the routine semen analysis.

Adsorption mechanisms of L-Glutathione on Au and controlled nano-patterning through Dip Pen Nanolithography

Energy Technology Data Exchange (ETDEWEB)

Calborean, A., E-mail: adrian.calborean@gmail.com [National Institute for Research and Development of Isotopic and Molecular Technologies, Donat 67-103, 400293 Cluj-Napoca (Romania); Martin, F.; Marconi, D.; Turcu, R.; Kacso, I.E.; Buimaga-Iarinca, L. [National Institute for Research and Development of Isotopic and Molecular Technologies, Donat 67-103, 400293 Cluj-Napoca (Romania); Graur, F. [Iuliu Haţieganu University of Medicine and Pharmacy Cluj-Napoca, Babeş 8, 400012 Cluj-Napoca (Romania); Turcu, I. [National Institute for Research and Development of Isotopic and Molecular Technologies, Donat 67-103, 400293 Cluj-Napoca (Romania)

2015-12-01

Dip Pen Nanolithography technique has been employed for patterning L-Glutathione tripeptide (L-y-glutamyl-L-cysteinyl-glycine) nanostructures at specific locations on metallic Au(111) substrate. The formed supramolecular architectures were designed through straight lines and dots serving as precursors for building blocks assemblies in nano-bio-electronics applications or as template structures for functionalized particles in the form of host–guest networks. Tween 20 polyoxyethylene surfactant concentrations ranging from 0.005 to 0.1% (v/v) into initial L-Glutathione tripeptide (2 mg mL{sup −1}) ink solutions were sequentially tested for the improvement of the ink delivery process and to assure an optimum uniformity and homogeneity over the patterned space. A strong relationship was found between the coated atomic force microscope (AFM) cantilever within the highly effective Tween 20 activator adjuvant and the molecular diffusion along concentration gradients. An increase in the driving force for ink transport from the AFM tip has been demonstrated within the highest 0.1% (v/v) TW 20 surfactant concentration, favoring the patterning of GSH molecules routinely with sub-100 nm resolution. Self-assembled monolayers of GSH were also fabricated and characterized in the light of X-ray photoemission spectroscopy (XPS) and ellipsometric optical measurements. Adsorption from water of L-Glutathione to the gold substrate is proven to be made by the thiol group of cysteine. Theoretical DFT approaches were applied for quantum chemical studies dedicated to electronic processes underneath molecular GSH/Au(111) systems. - Highlights: • Controlled nano-patterning of L-Glutathione was performed on Au by DPN. • Tween 20 was used for increasing driving force of molecular ink transport. • SAM's formation has described the adsorption mechanisms of L-Glutathione on Au. • Electronic properties of hybrid GSH/Au(111) structures were investigated by DFT. • Validation of

Glutathione oxidation correlates with one-lung ventilation time and PO2/FiO2 ratio during pulmonary lobectomy.

Science.gov (United States)

García-de-la-Asunción, José; García-Del-Olmo, Eva; Galan, Genaro; Guijarro, Ricardo; Martí, Francisco; Badenes, Rafael; Perez-Griera, Jaume; Duca, Alejandro; Delgado, Carlos; Carbonell, Jose; Belda, Javier

2016-09-01

During lung lobectomy, the operated lung completely collapses with simultaneous hypoxic pulmonary vasoconstriction, followed by expansion and reperfusion. Here, we investigated glutathione oxidation and lipoperoxidation in patients undergoing lung lobectomy, during one-lung ventilation (OLV) and after resuming two-lung ventilation (TLV), and examined the relationship with OLV duration. We performed a single-centre, observational, prospective study in 32 patients undergoing lung lobectomy. Blood samples were collected at five time-points: T0, pre-operatively; T1, during OLV, 5 minutes before resuming TLV; and T2, T3, and T4, respectively, 5, 60, and 180 minutes after resuming TLV. Samples were tested for reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione redox potential, and malondialdehyde (MDA). GSSG and MDA blood levels increased at T1, and increased further at T2. OLV duration directly correlated with marker levels at T1 and T2. Blood levels of GSH and glutathione redox potential decreased at T1-T3. GSSG, oxidized glutathione/total glutathione ratio, and MDA levels were inversely correlated with arterial blood PO2/FiO2 at T1 and T2. During lung lobectomy and OLV, glutathione oxidation, and lipoperoxidation marker blood levels increase, with further increases after resuming TLV. Oxidative stress degree was directly correlated with OLV duration, and inversely correlated with arterial blood PO2/FiO2.

Oxidative stress protection and glutathione metabolism in response to hydrogen peroxide and menadione in riboflavinogenic fungus Ashbya gossypii.

Science.gov (United States)

Kavitha, S; Chandra, T S

2014-11-01

Ashbya gossypii is a plant pathogen and a natural overproducer of riboflavin and is used for industrial riboflavin production. A few literature reports depict a link between riboflavin overproduction and stress in this fungus. However, the stress protection mechanisms and glutathione metabolism are not much explored in A. gossypii. In the present study, an increase in the activity of catalase and superoxide dismutase was observed in response to hydrogen peroxide and menadione. The lipid peroxide and membrane lipid peroxide levels were increased by H2O2 and menadione, indicating oxidative damage. The glutathione metabolism was altered with a significant increase in oxidized glutathione (GSSG), glutathione peroxidase (GPX), glutathione S transferase (GST), and glutathione reductase (GR) and a decrease in reduced glutathione (GSH) levels in the presence of H2O2 and menadione. Expression of the genes involved in stress mechanism was analyzed in response to the stressors by semiquantitative RT-PCR. The messenger RNA (mRNA) levels of CTT1, SOD1, GSH1, YAP1, and RIB3 were increased by H2O2 and menadione, indicating the effect of stress at the transcriptional level. A preliminary bioinformatics study for the presence of stress response elements (STRE)/Yap response elements (YRE) depicted that the glutathione metabolic genes, stress genes, and the RIB genes hosted either STRE/YRE, which may enable induction of these genes during stress.

Garlic protects the glutathione redox cycle in irradiated rats

International Nuclear Information System (INIS)

Abu-Ghadeer, A.R.M.; Osman, S.A.A.; Abbady, M.M.

1999-01-01

The aim of the present study is to evaluate the possible radioprotective role of garlic oil on the glutathione redox cycle (GSH, GSH-Px, GR and G6-PD) in blood and tissues (liver, spleen and intestine) of irradiated rats. Garlic oil was orally administered to rats (100 mg/Kg- b.w.) for 7 days before exposure to a fractionated of whole body gamma irradiation up to 9 Gy (3 Gy X 3 at 2 days intervals) and during the whole period of irradiation. The data showed that radiation exposure caused significant inhibition of the biochemical parameters in blood and tissue of irradiated rats all over the investigation periods (3,7 and 15 days). Garlic oil ameliorated the decrease in the tested parameters with noticeable effect on the 15 Th. day after radiation exposure. It is concluded that garlic oil could control the radiation induced changes in the glutathione redox cycle and provided some radioprotective effect

The depletion of nuclear glutathione impairs cell proliferation in 3t3 fibroblasts.

Directory of Open Access Journals (Sweden)

Jelena Markovic

2009-07-01

Full Text Available Glutathione is considered essential for survival in mammalian cells and yeast but not in prokaryotic cells. The presence of a nuclear pool of glutathione has been demonstrated but its role in cellular proliferation and differentiation is still a matter of debate.We have studied proliferation of 3T3 fibroblasts for a period of 5 days. Cells were treated with two well known depleting agents, diethyl maleate (DEM and buthionine sulfoximine (BSO, and the cellular and nuclear glutathione levels were assessed by analytical and confocal microscopic techniques, respectively. Both agents decreased total cellular glutathione although depletion by BSO was more sustained. However, the nuclear glutathione pool resisted depletion by BSO but not with DEM. Interestingly, cell proliferation was impaired by DEM, but not by BSO. Treating the cells simultaneously with DEM and with glutathione ethyl ester to restore intracellular GSH levels completely prevented the effects of DEM on cell proliferation.Our results demonstrate the importance of nuclear glutathione in the control of cell proliferation in 3T3 fibroblasts and suggest that a reduced nuclear environment is necessary for cells to progress in the cell cycle.

Induction of glutathione synthesis in human hepatocytes by acute and chronic arsenic exposure: Differential roles of mitogen-activated protein kinases

International Nuclear Information System (INIS)

Hou, Yongyong; Wang, Yi; Wang, Huihui; Xu, Yuanyuan

2014-01-01

Highlights: • Arsenic exposure increased intracellular levels of glutathione. • Mitogen-activated protein kinases were involved in glutathione homeostasis. • ERK contributed to glutathione synthesis during acute arsenic exposure. • Glutathione synthesis was regulated by p38 at least in part independent of NRF2 during chronic arsenic exposure. - Abstract: Glutathione (GSH) is a vital component of antioxidant defense which protects cells from toxic insults. Previously we found intracellular GSH was involved in cell resistance against arsenic-induced cytotoxicity. However, molecular mechanisms of GSH homeostasis during arsenic exposure are largely undefined. Here, we investigated roles of mitogen-activated protein kinases (MAPKs) in GSH synthesis pathway with two arsenic exposure strategies by using Chang human hepatocytes. In one strategy, acute arsenic exposure (20 μM, 24 h) was applied, as MAPK signaling is generally considered to be transient. In the other one, chronic arsenic exposure (500 nM, 20 weeks) was applied, which mimicked the general human exposure to arsenic. We found that acute arsenic exposure activated extracellular signal-regulated 1/2 kinases (ERK1/2) and c-Jun N-terminal kinase (JNK) in parallel with increased transcription and nuclear translocation of factor-erythroid 2-related factor 2 (NRF2) and enhanced expression of γ-glutamyl cysteine ligase catalytic subunit (GCLC), resulting in elevated intracellular GSH levels. Specific ERK inhibitor abolished arsenic-induced NRF2 nuclear translocation and GSH synthesis. During chronic arsenic exposure which induced a malignant cellular phenotype, continuous p38 activation and NRF2 nuclear translocation were observed with enhanced GSH synthesis. Specific p38 inhibitor attenuated arsenic-enhanced GSH synthesis without changing NRF2 nuclear translocation. Taken together, our results indicate MAPK pathways play an important role in cellular GSH homeostasis in response to arsenic. However, the

Short-term exercise worsens cardiac oxidative stress and fibrosis in 8-month-old db/db mice by depleting cardiac glutathione.

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Laher, Ismail; Beam, Julianne; Botta, Amy; Barendregt, Rebekah; Sulistyoningrum, Dian; Devlin, Angela; Rheault, Mark; Ghosh, Sanjoy

2013-01-01

Moderate exercise improves cardiac antioxidant status in young humans and animals with Type-2 diabetes (T2D). Given that both diabetes and advancing age synergistically decrease antioxidant expression in most tissues, it is unclear whether exercise can upregulate cardiac antioxidants in chronic animal models of T2D. To this end, 8-month-old T2D and normoglycemic mice were exercised for 3 weeks, and cardiac redox status was evaluated. As expected, moderate exercise increased cardiac antioxidants and attenuated oxidative damage in normoglycemic mice. In contrast, similar exercise protocol in 8-month-old db/db mice worsened cardiac oxidative damage, which was associated with a specific dysregulation of glutathione (GSH) homeostasis. Expression of enzymes for GSH biosynthesis [γ-glutamylcysteine synthase, glutathione reductase] as well as for GSH-mediated detoxification (glutathione peroxidase, glutathione-S-transferase) was lower, while toxic metabolites dependent on GSH for clearance (4-hydroxynonenal) were increased in exercised diabetic mice hearts. To validate GSH loss as an important factor for such aggravated damage, daily administration of GSH restored cardiac GSH levels in exercised diabetic mice. Such supplementation attenuated both oxidative damage and fibrotic changes in the myocardium. Expression of transforming growth factor beta (TGF-β) and its regulated genes which are responsible for such profibrotic changes were also attenuated with GSH supplementation. These novel findings in a long-term T2D animal model demonstrate that short-term exercise by itself can deplete cardiac GSH and aggravate cardiac oxidative stress. As GSH administration conferred protection in 8-month-old diabetic mice undergoing exercise, supplementation with GSH-enhancing agents may be beneficial in elderly diabetic patients undergoing exercise.

The glutathione cycle: Glutathione metabolism beyond the γ-glutamyl cycle.

Science.gov (United States)

Bachhawat, Anand Kumar; Yadav, Shambhu

2018-04-17

Glutathione was discovered in 1888, over 125 years ago. Since then, our understanding of various functions and metabolism of this important molecule has grown over these years. But it is only now, in the last decade, that a somewhat complete picture of its metabolism has emerged. Glutathione metabolism has till now been largely depicted and understood by the γ-glutamyl cycle that was proposed in 1970. However, new findings and knowledge particularly on the transport and degradation of glutathione have revealed that many aspects of the γ-glutamyl cycle are incorrect. Despite this, an integrated critical analysis of the cycle has never been undertaken and this has led to the cycle and its errors perpetuating in the literature. This review takes a careful look at the γ-glutamyl cycle and its shortcomings and presents a "glutathione cycle" that captures the current understanding of glutathione metabolism. © 2018 IUBMB Life, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

Transport of glutathione into the nucleus.

Science.gov (United States)

Queval, Guillaume; Foyer, Christine

2014-10-01

The tripeptide thiol glutathione (GSH) is present in the nucleus of plant and animal cells. However, the functions of GSH in the nucleus remain poorly characterised. GSH appears to become sequestered in the nucleus at the early stages of the cell cycle. As part of our search for proteins that may be involved in GSH transport into the nucleus, we studied the functions of the nucleoporin called Alacrima Achalasia aDrenal Insufficiency Neurologic disorder (ALADIN). ALADIN is encoded by the Achalasia-Addisonianism-Alacrimia (AAAS) gene in mammalian cells. Defects in ALADIN promote adrenal disorders and lead to the triple A syndrome in humans. The ALADIN protein localizes to the nuclear envelope in Arabidopsis thaliana and interacts with other components of the nuclear pore complex (NPC). We characterised the functions of the ALADIN protein in an Arabidopsis thaliana T-DNA insertion knockout mutant, which shows slow growth compared to the wild type. Copyright © 2014. Published by Elsevier Inc.

Activity-Based Probes for Isoenzyme- and Site-Specific Functional Characterization of Glutathione S -Transferases

Energy Technology Data Exchange (ETDEWEB)

Stoddard, Ethan G. [Chemical Biology and Exposure; Killinger, Bryan J. [Chemical Biology and Exposure; Nair, Reji N. [Chemical Biology and Exposure; Sadler, Natalie C. [Chemical Biology and Exposure; Volk, Regan F. [Chemical Biology and Exposure; Purvine, Samuel O. [Chemical Biology and Exposure; Shukla, Anil K. [Chemical Biology and Exposure; Smith, Jordan N. [Chemical Biology and Exposure; Wright, Aaron T. [Chemical Biology and Exposure

2017-11-01

Glutathione S-transferases (GSTs) comprise a highly diverse family of phase II drug metabolizing enzymes whose shared function is the conjugation of reduced glutathione to various endo- and xenobiotics. Although the conglomerate activity of these enzymes can be measured by colorimetric assays, measurement of the individual contribution from specific isoforms and their contribution to the detoxification of xenobiotics in complex biological samples has not been possible. For this reason, we have developed two activity-based probes that characterize active glutathione transferases in mammalian tissues. The GST active site is comprised of a glutathione binding “G site” and a distinct substrate binding “H site”. Therefore, we developed (1) a glutathione-based photoaffinity probe (GSH-ABP) to target the “G site”, and (2) a probe designed to mimic a substrate molecule and show “H site” activity (GST-ABP). The GSH-ABP features a photoreactive moiety for UV-induced covalent binding to GSTs and glutathione-binding enzymes. The GST-ABP is a derivative of a known mechanism-based GST inhibitor that binds within the active site and inhibits GST activity. Validation of probe targets and “G” and “H” site specificity was carried out using a series of competitors in liver homogenates. Herein, we present robust tools for the novel characterization of enzyme- and active site-specific GST activity in mammalian model systems.

Effects of methylmercury exposure on glutathione metabolism, oxidative stress, and chromosomal damage in captive-reared common loon (Gavia immer) chicks

International Nuclear Information System (INIS)

Kenow, Kevin P.; Hoffman, David J.; Hines, Randy K.; Meyer, Michael W.; Bickham, John W.; Matson, Cole W.; Stebbins, Katie R.; Montagna, Paul; Elfessi, Abdulaziz

2008-01-01

We quantified the level of dietary mercury (Hg), delivered as methylmercury chloride (CH 3 HgCl), associated with negative effects on organ and plasma biochemistries related to glutathione (GSH) metabolism and oxidative stress, and chromosomal damage in captive-reared common loon (Gavia immer) chicks reared from hatch to 105 days. Mercury-associated effects related to oxidative stress and altered glutathione metabolism occurred at 1.2 μg Hg/g and 0.4 μg Hg/g, an ecologically relevant dietary mercury level, but not at 0.08 μg Hg/g. Among the variables that contributed most to dissimilarities in tissue chemistries between control and treatment groups were increased levels of oxidized glutathione (GSSG), GSH peroxidase, and the ratio of GSSG to GSH in brain tissue; increased levels of hepatic GSH; and decreased levels of hepatic glucose-6-phosphate dehydrogenase (G-6-PDH). Our results also suggest that chronic exposure to environmentally relevant dietary Hg levels did not result in statistically significant somatic chromosomal damage in common loon chicks. - Oxidative stress and altered glutathione metabolism were evident in common loon chicks exposed to ≥0.4 μg Hg as CH 3 HgCl per gram wet food intake

Glutathione modulation in cancer treatment: will it work

International Nuclear Information System (INIS)

Mitchell, J.B.; Cook, J.A.; DeGraff, W.; Glatstein, E.; Russo, A.

1989-01-01

Glutathione (GSH) assumes a pivotal role in numerous cellular functions including bioreductive reactions, maintenance of enzyme activity, amino acid transport, protection from harmful oxidative species, and detoxification of xenobiotics. The importance of GSH in modifying the cellular response to several anti-cancer treatment modalities has become better appreciated with the introduction of agents which can either decrease or elevate GSH levels in cells and tissues. In general, GSH depletion has been demonstrated to further enhance the cytotoxicity of several chemotherapy drugs and nitroimidazole hypoxic cell radiosensitizers. Conversely, GSH elevation affords varying degrees of protection. Whether or not GSH modulating agents will be useful as an adjuvant to selected cancer treatment modalities will depend on whether differential levels of GSH can be achieved in tumor versus normal tissues. Accurate GSH measurements in tumor and normal tissues will be required to adequately use and interpret the results of clinical studies where GSH modulating agents are employed. Precise tumor GSH measurements pose a considerable challenge due to the complicated cellular makeup of tumors.44 references

Antioxidant activity of melatonin and glutathione interacting with hydroxyl- and superoxide anion radicals

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T. Y. Kuznetsova

2017-12-01

Full Text Available Based on the analysis of the results obtained by quantum chemical modeling of interaction between reduced glutathione (GSH and melatonin (MLT molecules with oxygen radicals (•OH and • OOˉ it was found that this interaction occured following the acid-base mechanism, where MLT and GSH acted as a base in respect of •OH, and as acid in respect of •OOˉ. We have carried out the correlation of the results of quantum chemical calculations (density redistribution, energetic characteristics under the interaction of MLT and GSH molecules with •OH and •OOˉ in changing macroscopic properties of the process of electroreduction of free oxygen radicals in the presence of antioxidants (potential and maximal current wave reduction waves. This was a direct experimental macroscale evidence of the results of theoretical modeling at the nanoscale level that pointed to a marked antioxidant activity of glutathione compared with melatonin.

Impedimetric Urea Biosensor Based on Modified Gold Electrode with Urease Immobilized on Glutathione Layer

OpenAIRE

Houcine BARHOUMI; Abderrazak MAAREF; Nicole JAFFREZIC-RENAULT

2014-01-01

In this work, a glutathione (GSH) modified gold microelectrode was used for the covalent immobilization of urease biomolecules via the glutaraldehyde-coupling agent. The self- assembled monolayers (SAMs) onto the gold surface was investigated by using the electrochemical impedance spectroscopy measurements (EIS). Before urease grafting, a significant interaction was noticed between urea and the glutathione layer by forming hydrogen bonds. The H-NMR analysis was carried out to highlight the po...

A phenomics approach to the analysis of the influence of glutathione on leaf area and abiotic stress tolerance in Arabidopsis thaliana

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Daniel eSchnaubelt

2013-11-01

Full Text Available Reduced glutathione (GSH is an abundant low molecular weight plant thiol. It fulfils multiple functions in plant biology, many of which remain poorly characterised. A phenomics approach was therefore used to investigate the effects of glutathione homeostasis on growth and stress tolerance in Arabidopsis thaliana. Rosette leaf area was compared in mutants that are either defective in GSH synthesis (cad2, pad2 and rax1 or the export of γ-glutamyl cysteine and GSH from the chloroplast (clt and in wild type plants under standard growth conditions and following exposure to a range of abiotic stress treatments, including oxidative stress, water stress and high salt. In the absence of stress, the GSH synthesis mutants had a significantly lower leaf area than the wild type. Conversely, the clt mutant has a greater leaf area and a significantly reduced lateral root density than the wild type. These findings demonstrate that cellular glutathione homeostasis exerts an influence on root architecture and on rosette area. An impaired capacity to synthesise GSH or a specific depletion of the cytosolic GSH pool did not adversely affect leaf area in plants exposed to short term abiotic stress. However, the negative effects of long term exposure to oxidative stress and high salt on leaf area were less marked in the GSH synthesis mutants than the wild type. These findings demonstrate the importance of cellular glutathione homeostasis in the regulation of plant growth under optimal and stress conditions.

A phenomics approach to the analysis of the influence of glutathione on leaf area and abiotic stress tolerance in Arabidopsis thaliana.

Science.gov (United States)

Schnaubelt, Daniel; Schulz, Philipp; Hannah, Matthew A; Yocgo, Rosita E; Foyer, Christine H

2013-01-01

Reduced glutathione (GSH) is an abundant low molecular weight plant thiol. It fulfills multiple functions in plant biology, many of which remain poorly characterized. A phenomics approach was therefore used to investigate the effects of glutathione homeostasis on growth and stress tolerance in Arabidopsis thaliana. Rosette leaf area was compared in mutants that are either defective in GSH synthesis (cad2, pad2, and rax1) or the export of γ-glutamylcysteine and GSH from the chloroplast (clt) and in wild-type plants under standard growth conditions and following exposure to a range of abiotic stress treatments, including oxidative stress, water stress, and high salt. In the absence of stress, the GSH synthesis mutants had a significantly lower leaf area than the wild type. Conversely, the clt mutant has a greater leaf area and a significantly reduced lateral root density than the wild type. These findings demonstrate that cellular glutathione homeostasis exerts an influence on root architecture and on rosette area. An impaired capacity to synthesize GSH or a specific depletion of the cytosolic GSH pool did not adversely affect leaf area in plants exposed to short-term abiotic stress. However, the negative effects of long-term exposure to oxidative stress and high salt on leaf area were less marked in the GSH synthesis mutants than the wild type. These findings demonstrate the importance of cellular glutathione homeostasis in the regulation of plant growth under optimal and stress conditions.

Quantitative imaging of glutathione in live cells using a reversible reaction-based ratiometric fluorescent probe

Science.gov (United States)

Glutathione (GSH) plays an important role in maintaining redox homeostasis inside cells. Currently, there are no methods available to quantitatively assess the GSH concentration in live cells. Live cell fluorescence imaging revolutionized the understanding of cell biology and has become an indispens...

Effects of Ionizing Radiation and Glutathione Precursor on Antioxidant Enzyme and Cell Survival in Yeast

Energy Technology Data Exchange (ETDEWEB)

Kim, Jinkyu; Roh, Changhyun; Ryu, Taeho; Park, Jiyoung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Nili, Michael A. [Oxiage Cosmeceutical Research Institute, Virginia (United States)

2013-05-15

Cells react to such an induced oxidative stress through scavenging the generated reactive oxygen species to reduce oxidative damage. Antioxidant enzymes such as glutathione peroxidase, catalase, and superoxide dismutase are immediately triggered for reactive oxygen species. N-acetyl-L-cysteine (NAC), a precursor of glutathione, is one of the antioxidants. The effect of NAC as an antioxidant and/or a cell rescue agent was investigated in the present study. Glutathione (GSH) is the most abundant intracellular thiol, which involves in antioxidant defense via direct interaction with ROS or via activities of detoxication enzymes like glutathione peroxidases (GPx). NAC flowed in the cell is converted to cysteine by deacetylation, that is supplied to the depleted GSH by oxidative stress. NAC prevents the depletion of GSH by radiation, increases the production of GSH, and improves enzymes activity such as GPx and alkaline phosphatase. Cell growth and survivorship and transcriptional level of glutathione gene are analyzed in two yeast strains exposed to combined treatment of NAC with gamma-rays. The effect of NAC on cell growth was measured during 72 hours. The cell growth was hampered by higher concentrations of NAC at stationary phase. NAC, however, didn't affect the cell division at the exponential phase. The survival of the cells decreased with radiation dose. The cell viability of the strain W303-1A was reduced significantly at the low dose (10 and 30 Gy). By comparison, the strain W303-1A was more sensitive to radiation with having a half lethal dose (LD{sub 50}) of about 20 Gy. The quantitative RT-PCR analysis showed that the transcriptional expression of antioxidant enzyme gene GPX1 increased after irradiation while the expression of the gene decreased by the combined treatment of NAC with 100 Gy radiation. The present study shows that NAC can directly scavenge ROS against oxidative stress in vivo. In conclusion, NAC can prevent radiation-induced oxidative

Effects of Ionizing Radiation and Glutathione Precursor on Antioxidant Enzyme and Cell Survival in Yeast

International Nuclear Information System (INIS)

Kim, Jinkyu; Roh, Changhyun; Ryu, Taeho; Park, Jiyoung; Nili, Michael A.

2013-01-01

Cells react to such an induced oxidative stress through scavenging the generated reactive oxygen species to reduce oxidative damage. Antioxidant enzymes such as glutathione peroxidase, catalase, and superoxide dismutase are immediately triggered for reactive oxygen species. N-acetyl-L-cysteine (NAC), a precursor of glutathione, is one of the antioxidants. The effect of NAC as an antioxidant and/or a cell rescue agent was investigated in the present study. Glutathione (GSH) is the most abundant intracellular thiol, which involves in antioxidant defense via direct interaction with ROS or via activities of detoxication enzymes like glutathione peroxidases (GPx). NAC flowed in the cell is converted to cysteine by deacetylation, that is supplied to the depleted GSH by oxidative stress. NAC prevents the depletion of GSH by radiation, increases the production of GSH, and improves enzymes activity such as GPx and alkaline phosphatase. Cell growth and survivorship and transcriptional level of glutathione gene are analyzed in two yeast strains exposed to combined treatment of NAC with gamma-rays. The effect of NAC on cell growth was measured during 72 hours. The cell growth was hampered by higher concentrations of NAC at stationary phase. NAC, however, didn't affect the cell division at the exponential phase. The survival of the cells decreased with radiation dose. The cell viability of the strain W303-1A was reduced significantly at the low dose (10 and 30 Gy). By comparison, the strain W303-1A was more sensitive to radiation with having a half lethal dose (LD 50 ) of about 20 Gy. The quantitative RT-PCR analysis showed that the transcriptional expression of antioxidant enzyme gene GPX1 increased after irradiation while the expression of the gene decreased by the combined treatment of NAC with 100 Gy radiation. The present study shows that NAC can directly scavenge ROS against oxidative stress in vivo. In conclusion, NAC can prevent radiation-induced oxidative stress by

A quick response fluorescent probe based on coumarin and quinone for glutathione and its application in living cells

Energy Technology Data Exchange (ETDEWEB)

Dai, Xi [Institute of Organic Chemistry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Du, Zhi-Fang [Taishan College, Shandong University, Jinan 250100 (China); Wang, Li-Hong; Miao, Jun-Ying [Institute of Developmental Biology, School of Life Science, Shandong University, Jinan 250100 (China); Zhao, Bao-Xiang, E-mail: bxzhao@sdu.edu.cn [Institute of Organic Chemistry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China)

2016-05-30

We have designed and synthesized a simple but effective fluorescent probe for sensing glutathione (GSH) by PET process based on coumarin and quinone, which worked as fluorophore and reaction site, respectively. The probe could discriminate GSH from cysteine and homocysteine within 1 min in PBS-buffered solution. The sensing mechanism was confirmed by density functional theory (DFT), viscosity test, fluorescence spectrum analysis and HRMS, respectively. The probe has a low limit of detection (0.1 μM) and finally been used in cell imaging successfully. - Highlights: • This probe can discriminate glutathione from sulfhydryl compound by PET process. • This probe can be used to determine glutathione in aqueous solution within 1 min. • This probe has been successfully applied in living cell image.

A quick response fluorescent probe based on coumarin and quinone for glutathione and its application in living cells

International Nuclear Information System (INIS)

Dai, Xi; Du, Zhi-Fang; Wang, Li-Hong; Miao, Jun-Ying; Zhao, Bao-Xiang

2016-01-01

We have designed and synthesized a simple but effective fluorescent probe for sensing glutathione (GSH) by PET process based on coumarin and quinone, which worked as fluorophore and reaction site, respectively. The probe could discriminate GSH from cysteine and homocysteine within 1 min in PBS-buffered solution. The sensing mechanism was confirmed by density functional theory (DFT), viscosity test, fluorescence spectrum analysis and HRMS, respectively. The probe has a low limit of detection (0.1 μM) and finally been used in cell imaging successfully. - Highlights: • This probe can discriminate glutathione from sulfhydryl compound by PET process. • This probe can be used to determine glutathione in aqueous solution within 1 min. • This probe has been successfully applied in living cell image.

Metabolic cooperation of ascorbic acid and glutathione in normal and vitamin C-deficient ODS rats.

Science.gov (United States)

Wang, Y; Kashiba, M; Kasahara, E; Tsuchiya, M; Sato, E F; Utsumi, K; Inoue, M

2001-01-01

Although the coordination of various antioxidants is important for the protection of organisms from oxidative stress, dynamic aspects of the interaction of endogenous antioxidants in vivo remain to be elucidated. We studied the metabolic coordination of two naturally occurring water-soluble antioxidants, ascorbic acid (AA) and reduced glutathione (GSH), in liver, kidney and plasma of control and scurvy-prone osteogenic disorder Shionogi (ODS) rats that hereditarily lack the ability to synthesize AA. When supplemented with AA, its levels in liver and kidney of ODS rats increased to similar levels of those in control rats. Hepato-renal levels of glutathione were similar with the two animal groups except for the slight increase in its hepatic levels in AA-supplemented ODS rats. Administration of L-buthionine sulfoximine (BSO), a specific inhibitor of GSH synthesis, rapidly decreased the hepato-renal levels of glutathione in a biphasic manner, a rapid phase followed by a slower phase. Kinetic analysis revealed that glutathione turnover was enhanced significantly in liver mitochondria and renal cytosol of ODS rats. Administration of BSO significantly increased AA levels in the liver and kidney of control rats but decreased them in AA-supplemented ODS rats. Kinetic analysis revealed that AA is synthesized by control rat liver by some BSO-enhanced mechanism and the de novo synthesized AA is transferred to the kidney. Such a coordination of the metabolism of GSH and AA in liver and kidney is suppressed in AA-deficient ODS rats. These and other results suggest that the metabolism of AA and GSH forms a compensatory network by which oxidative stress can be decreased.

RED BLOOD CELL AND WHOLE BLOOD GLUTATHIONE REDOX STATUS IN ENDURANCE-TRAINED MEN FOLLOWING A SKI MARATHON

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Eve Unt

2008-09-01

Full Text Available The aim of the present study was to evaluate the changes in glutathione redox ratio (GSSG·GSH-1 in red blood cells (RBCs and whole blood in well-trained men following a ski marathon. 16 male subjects (27.0 ± 4.7 yrs, 1.81 ± 0.06 m, 77.6 ± 9.6 kg, VO2max 66.2 ± 5.7 ml·kg-1·min-1 were examined before the competition (pre- COMP, after the competition (post-COMP and during an 18-hour recovery period (RECOV. There was a slight decrease in reduced glutathione (GSH in blood and in RBCs in post-COMP. During RECOV, the GSH level in blood was reduced, the GSH level in RBCs was significantly elevated (a statistically significant difference as compared to the pre-COMP level. The post-COMP GSSG·GSH-1 in full blood did not increase significantly, but its increase was statistically significant during the 18-hour recovery period. During the post-COMP and RECOV, the GSSG·GSH-1 in RBCs slightly decreased in comparison with the pre-COMP. Vitamin C concentration in serum increased in post-COMP (49% vs. pre- COMP and decreased to the baseline level during RECOV. In conclusion, our data show that acute exercise slightly increases the GSSG·GSH-1 in whole blood, while GSSG·GSH-1 in RBCs significantly decreases. Thus, exercise-related changes in the non-enzymatic components of the glutathione system (GSSG and GSH in whole blood and RBCs are not identical

Effects of cisplatin on lipid peroxidation and the glutathione redox status in the liver of male rats: The protective role of selenium

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Trbojević Ivana S.

2010-01-01

Full Text Available The role of oxidative stress in cisplatin (CP toxicity and its prevention by pretreatment with selenium (Se was investigated. Male Wistar albino rats were injected with a single dose of cisplatin (7.5 mg CP/kg b.m., i.p. and selenium (6 mg Se/kg b.m, as Na2SeO3, i.p. alone or in combination. The results suggest that CP intoxication induces oxidative stress and alters the glutathione redox status: reduced glutathione (GSH, oxidized glutathione (GSSG and the GSH/GSSG ratio (GSH RI, resulting in increased lipid peroxidation (LPO in rat liver. The pretreatment with selenium prior to CP treatment showed a protective effect against the toxic influence of CP on peroxidation of the membrane lipids and an altering of the glutathione redox status in the liver of rats. From our results we conclude that selenium functions as a potent antioxidant and suggest that it can control CP-induced hepatotoxicity in rats.

Glutathione reductase: solvent equilibrium and kinetic isotope effects

International Nuclear Information System (INIS)

Wong, K.K.; Vanoni, M.A.; Blanchard, J.S.

1988-01-01

Glutathione reductase catalyzes the NADPH-dependent reduction of oxidized glutathione (GSSG). The kinetic mechanism is ping-pong, and we have investigated the rate-limiting nature of proton-transfer steps in the reactions catalyzed by the spinach, yeast, and human erythrocyte glutathione reductases using a combination of alternate substrate and solvent kinetic isotope effects. With NADPH or GSSG as the variable substrate, at a fixed, saturating concentration of the other substrate, solvent kinetic isotope effects were observed on V but not V/K. Plots of Vm vs mole fraction of D 2 O (proton inventories) were linear in both cases for the yeast, spinach, and human erythrocyte enzymes. When solvent kinetic isotope effect studies were performed with DTNB instead of GSSG as an alternate substrate, a solvent kinetic isotope effect of 1.0 was observed. Solvent kinetic isotope effect measurements were also performed on the asymmetric disulfides GSSNB and GSSNP by using human erythrocyte glutathione reductase. The Km values for GSSNB and GSSNP were 70 microM and 13 microM, respectively, and V values were 62 and 57% of the one calculated for GSSG, respectively. Both of these substrates yield solvent kinetic isotope effects greater than 1.0 on both V and V/K and linear proton inventories, indicating that a single proton-transfer step is still rate limiting. These data are discussed in relationship to the chemical mechanism of GSSG reduction and the identity of the proton-transfer step whose rate is sensitive to solvent isotopic composition. Finally, the solvent equilibrium isotope effect measured with yeast glutathione reductase is 4.98, which allows us to calculate a fractionation factor for the thiol moiety of GSH of 0.456

Glutathione-responsive core cross-linked micelles for controlled cabazitaxel delivery

Science.gov (United States)

Han, Xiaoxiong; Gong, Feirong; Sun, Jing; Li, Yueqi; Liu, XiaoFei; Chen, Dan; Liu, Jianwen; Shen, Yaling

2018-02-01

Stimulus-responsive polymeric micelles (PMs) have recently received attention due to the controlled delivery of drug or gene for application in cancer diagnosis and treatment. In this work, novel glutathione-responsive PMs were prepared to encapsulate hydrophobic antineoplastic drug, cabazitaxel (CTX), to improve its solubility and toxicity. These CTX-loaded micelles core cross-linked by disulfide bonds (DCL-CTX micelles) were prepared by a novel copolymer, lipoic acid grafted mPEG-PLA. These micelles had regular spherical shape, homogeneous diameter of 18.97 ± 0.23 nm, and a narrow size distribution. The DCL-CTX micelles showed high encapsulation efficiency of 98.65 ± 1.77%, and the aqueous solubility of CTX was improved by a factor of 1:1200. In vitro release investigation showed that DCL-CTX micelles were stable in the medium without glutathione (GSH), whereas the micelles had burst CTX release in the medium with 10 mM GSH. Cell uptake results implied that DCL-CTX micelles were internalized into MCF-7 cells through clathrin-mediated endocytosis and released cargo more effectively than Jevtana (commercially available CTX) owing to GSH-stimulated degradation. In MTT assay against MCF-7 cells, these micelles inhibited tumor cell proliferation more effectively than Jevtana due to their GSH-responsive CTX release. All results revealed the potency of GSH-responsive DCL-CTX micelles for stable delivery in blood circulation and for intracellular GSH-trigged release of CTX. Therefore, DCL-CTX micelles show potential as safe and effective CTX delivery carriers and as a cancer chemotherapy formulation.

Effects of methylmercury exposure on glutathione metabolism, oxidative stress, and chromosomal damage in captive-reared common loon (Gavia immer) chicks

Energy Technology Data Exchange (ETDEWEB)

Kenow, Kevin P. [U.S. Geological Survey, Upper Midwest Environmental Sciences Center, 2630 Fanta Reed Road, La Crosse, WI 54603 (United States)], E-mail: kkenow@usgs.gov; Hoffman, David J. [U.S. Geological Survey, Patuxent Wildlife Research Center, 10300 Baltimore Avenue, Beltsville, MD 20705 (United States)], E-mail: djhoffman@usgs.gov; Hines, Randy K. [U.S. Geological Survey, Upper Midwest Environmental Sciences Center, 2630 Fanta Reed Road, La Crosse, WI 54603 (United States)], E-mail: rkhines@usgs.gov; Meyer, Michael W. [Wisconsin Department of Natural Resources, 107 Sutliff Avenue, Rhinelander, WI 54501 (United States)], E-mail: michael.meyer@dnr.state.wi.us; Bickham, John W. [Center for the Environment and Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907 (United States)], E-mail: bickham@purdue.edu; Matson, Cole W. [Integrated Toxicology and Environmental Health Program, Duke University, Durham, NC 27708 (United States)], E-mail: matson@duke.edu; Stebbins, Katie R. [U.S. Geological Survey, Patuxent Wildlife Research Center, 10300 Baltimore Avenue, Beltsville, MD 20705 (United States); Montagna, Paul [Texas A and M University-Corpus Christi, Harte Research Institute, Corpus Christi, TX (United States)], E-mail: paul.montagna@tamucc.edu; Elfessi, Abdulaziz [University of Wisconsin-La Crosse, La Crosse, WI 54601 (United States)], E-mail: elfessi.abdu@uwlax.edu

2008-12-15

We quantified the level of dietary mercury (Hg), delivered as methylmercury chloride (CH{sub 3}HgCl), associated with negative effects on organ and plasma biochemistries related to glutathione (GSH) metabolism and oxidative stress, and chromosomal damage in captive-reared common loon (Gavia immer) chicks reared from hatch to 105 days. Mercury-associated effects related to oxidative stress and altered glutathione metabolism occurred at 1.2 {mu}g Hg/g and 0.4 {mu}g Hg/g, an ecologically relevant dietary mercury level, but not at 0.08 {mu}g Hg/g. Among the variables that contributed most to dissimilarities in tissue chemistries between control and treatment groups were increased levels of oxidized glutathione (GSSG), GSH peroxidase, and the ratio of GSSG to GSH in brain tissue; increased levels of hepatic GSH; and decreased levels of hepatic glucose-6-phosphate dehydrogenase (G-6-PDH). Our results also suggest that chronic exposure to environmentally relevant dietary Hg levels did not result in statistically significant somatic chromosomal damage in common loon chicks. - Oxidative stress and altered glutathione metabolism were evident in common loon chicks exposed to {>=}0.4 {mu}g Hg as CH{sub 3}HgCl per gram wet food intake.

Glycine facilitates gamma-glutamylcysteinylethyl ester-mediated increase in liver glutathione level.

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Nishida, K; Ohta, Y; Ishiguro, I

1997-08-27

gamma-Glutamylcysteinylethyl ester (gamma-GCE) increases reduced glutathione (GSH) levels in GSH-depleted rat hepatocytes. Because glycine, a constituent of GSH, exists at 0.3 to 0.4 mM in rat plasma, we examined the influence of glycine added to the medium on the action of gamma-GCE to increase GSH levels in the rat hepatocytes. Glycine (0.2-0.8 mM) dose-dependently enhanced gamma-GCE-mediated increase in intracellular GSH levels with an increase in intracellular gamma-GCE levels. These results indicate that exogenous glycine facilitates gamma-GCE-mediated increase in intracellular GSH levels in rat hepatocytes possibly by enhancing the uptake of gamma-GCE into the cells.

[The activity of glutathione antioxidant system at melaksen and valdoxan action under experimental hyperthyroidism in rats].

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Gorbenko, M V; Popova, T N; Shul'gin, K K; Popov, S S

2013-01-01

Investigation of glutathione antioxidant system activity and diene conjugates content in rats liver and blood serum at the influence of melaksen and valdoxan under experimental hyperthyroidism (EG) has been revealed. It has been established that the activities of glutathione reductase (GR), glutathione peroxidase (GP) and glutathione transferase (GT), growing at pathological conditions, change to the side of control value at these substunces introduction. Reduced glutathione content (GSH) at melaxen and valdoxan action increased compared with values under the pathology, that, obviously, could be associated with a reduction of its spending on the detoxication of free radical oxidation (FRO) toxic products. Diene conjugates level in rats liver and blood serum, increasing at experimental hyperthyroidism conditions, under introduction of melatonin level correcting drugs, also approached to the control meaning. Results of the study indicate on positive effect of melaxen and valdoxan on free radical homeostasis, that appears to be accompanied by decrease of load on the glutathione antioxidant system in comparison with the pathology.

Kinetic study of the interaction of glutathione with four antitumor disulfides: possible mechanism for cellular glutathione depletion.

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Kirkpatrick, D L

1989-01-01

The reactions between the cellular tripeptide, glutathione (GSH) and four disulfide derivatives of 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG) (compounds 1-4) were studied kinetically. The decyl and phenyl derivatives of 6-MP and 6-TG were reacted with GSH in phosphate buffer (pH 7.4 or 6.0) at 25.0 degrees C and were monitored spectrophotometrically by observing the release of 6-MP and 6-TG. Second order kinetics were observed, with rate constants of 142, 564, 4174 and 429 M-1 s-1 being measured for compounds 1-4, respectively. When the reactions were carried out in the presence of GSH-S-transferase the rates were enhanced 1.3-5.4 times those observed in the absence of enzyme. Products of the reactions were isolated by chromatography and tentatively identified by TLC or fast atom bombardment mass spectrometry. It was observed that GSH reacted with each disulfide in a 1:1 manner, forming a mixed disulfide between GSH and decanethiol or thiophenol while releasing 6-MP or 6-TG. It was concluded that the reported depletion of GSH from EMT6 cells after exposure to these disulfides could be due to their reaction with GSH, and the formation of the mixed disulfides.

Involvement of the VDE homing endonuclease and rapamycin in regulation of the Saccharomyces cerevisiae GSH11 gene encoding the high affinity glutathione transporter.

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Miyake, Tsuyoshi; Hiraishi, Hiroyuki; Sammoto, Hiroyuki; Ono, Bun-Ichiro

2003-10-10

The Saccharomyces cerevisiae gene HGT1/GSH11 encodes the high affinity glutathione transporter and is repressed by cysteine added to the culture medium. It has been found previously that a 5'-upstream cis-element, CCGCCACAC, is responsible for regulating GSH11 expression and that several proteins bind to this element (Miyake, T., Kanayama, M., Sammoto, H., and Ono, B. (2002) Mol. Genet. Genomics 266, 1004-1011). In this report we present evidence that the most prominent of these proteins is VDE, known previously as the homing endonuclease encoded by VMA1. We show also that GSH11 is not expressed in a VDE-deleted strain and that inability to express the GSH11 of this strain is overcome by introduction of the coding region of VDE or the entire VMA1 gene. It is also found that VDE does not cut DNA in the vicinity of the GSH11 cis-element. Rapamycin, an inhibitor of the target of rapamycin (TOR) signal-transduction system, is found to enhance expression of GSH11 in a VDE-dependent manner under conditions of sulfur starvation. These results indicate that GSH11 is regulated by a system sensitive to sulfur starvation (presumably via cysteine depletion) and a more general system involving the nutritional starvation signal mediated by the TOR system. Both systems need to be operational (inhibition of TOR and sulfur starvation) for full expression of GSH11.

Sulforaphane restores cellular glutathione levels and reduces chronic periodontitis neutrophil hyperactivity in vitro.

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Irundika H K Dias

Full Text Available The production of high levels of reactive oxygen species by neutrophils is associated with the local and systemic destructive phenotype found in the chronic inflammatory disease periodontitis. In the present study, we investigated the ability of sulforaphane (SFN to restore cellular glutathione levels and reduce the hyperactivity of circulating neutrophils associated with chronic periodontitis. Using differentiated HL60 cells as a neutrophil model, here we show that generation of extracellular O2 (. - by the nicotinamide adenine dinucleotide (NADPH oxidase complex is increased by intracellular glutathione depletion. This may be attributed to the upregulation of thiol regulated acid sphingomyelinase driven lipid raft formation. Intracellular glutathione was also lower in primary neutrophils from periodontitis patients and, consistent with our previous findings, patients neutrophils were hyper-reactive to stimuli. The activity of nuclear factor erythroid-2-related factor 2 (Nrf2, a master regulator of the antioxidant response, is impaired in circulating neutrophils from chronic periodontitis patients. Although patients' neutrophils exhibit a low reduced glutathione (GSH/oxidised glutathione (GSSG ratio and a higher total Nrf2 level, the DNA-binding activity of nuclear Nrf2 remained unchanged relative to healthy controls and had reduced expression of glutamate cysteine ligase catalytic (GCLC, and modifier (GCLM subunit mRNAs, compared to periodontally healthy subjects neutrophils. Pre-treatment with SFN increased expression of GCLC and GCM, improved intracellular GSH/GSSG ratios and reduced agonist-activated extracellular O2 (. - production in both dHL60 and primary neutrophils from patients with periodontitis and controls. These findings suggest that a deficiency in Nrf2-dependent pathways may underpin susceptibility to hyper-reactivity in circulating primary neutrophils during chronic periodontitis.

Sulforaphane restores cellular glutathione levels and reduces chronic periodontitis neutrophil hyperactivity in vitro.

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Dias, Irundika H K; Chapple, Ian L C; Milward, Mike; Grant, Melissa M; Hill, Eric; Brown, James; Griffiths, Helen R

2013-01-01

The production of high levels of reactive oxygen species by neutrophils is associated with the local and systemic destructive phenotype found in the chronic inflammatory disease periodontitis. In the present study, we investigated the ability of sulforaphane (SFN) to restore cellular glutathione levels and reduce the hyperactivity of circulating neutrophils associated with chronic periodontitis. Using differentiated HL60 cells as a neutrophil model, here we show that generation of extracellular O2 (. -) by the nicotinamide adenine dinucleotide (NADPH) oxidase complex is increased by intracellular glutathione depletion. This may be attributed to the upregulation of thiol regulated acid sphingomyelinase driven lipid raft formation. Intracellular glutathione was also lower in primary neutrophils from periodontitis patients and, consistent with our previous findings, patients neutrophils were hyper-reactive to stimuli. The activity of nuclear factor erythroid-2-related factor 2 (Nrf2), a master regulator of the antioxidant response, is impaired in circulating neutrophils from chronic periodontitis patients. Although patients' neutrophils exhibit a low reduced glutathione (GSH)/oxidised glutathione (GSSG) ratio and a higher total Nrf2 level, the DNA-binding activity of nuclear Nrf2 remained unchanged relative to healthy controls and had reduced expression of glutamate cysteine ligase catalytic (GCLC), and modifier (GCLM) subunit mRNAs, compared to periodontally healthy subjects neutrophils. Pre-treatment with SFN increased expression of GCLC and GCM, improved intracellular GSH/GSSG ratios and reduced agonist-activated extracellular O2 (. -) production in both dHL60 and primary neutrophils from patients with periodontitis and controls. These findings suggest that a deficiency in Nrf2-dependent pathways may underpin susceptibility to hyper-reactivity in circulating primary neutrophils during chronic periodontitis.

Nanotoxicity of pure silica mediated through oxidant generation rather than glutathione depletion in human lung epithelial cells.

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Akhtar, Mohd Javed; Ahamed, Maqusood; Kumar, Sudhir; Siddiqui, Huma; Patil, Govil; Ashquin, Mohd; Ahmad, Iqbal

2010-10-09

Though, oxidative stress has been implicated in silica nanoparticles induced toxicity both in vitro and in vivo, but no similarities exist regarding dose-response relationship. This discrepancy may, partly, be due to associated impurities of trace metals that may present in varying amounts. Here, cytotoxicity and oxidative stress parameters of two sizes (10 nm and 80 nm) of pure silica nanoparticles was determined in human lung epithelial cells (A549 cells). Both sizes of silica nanoparticles induced dose-dependent cytotoxicity as measured by MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] and lactate dehydrogenase (LDH) assays. Silica nanoparticles were also found to induce oxidative stress in dose-dependent manner indicated by induction of reactive oxygen species (ROS) generation, and membrane lipid peroxidation (LPO). However, both sizes of silica nanoparticles had little effect on intracellular glutathione (GSH) level and the activities of glutathione metabolizing enzymes; glutathione reductase (GR) and glutathione peroxidase (GPx). Buthionine-[S,R]-sulfoximine (BSO) plus silica nanoparticles did not result in significant GSH depletion than that caused by BSO alone nor N-acetyl cysteine (NAC) afforded significant protection from ROS and LPO induced by silica nanoparticles. The rather unaltered level of GSH is also supported by finding no appreciable alteration in the level of GR and GPx. Our data suggest that the silica nanoparticles exert toxicity in A549 cells through the oxidant generation (ROS and LPO) rather than the depletion of GSH. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Relations between metals (Zn, Pb, Cd and Cu) and glutathione-dependent detoxifying enzymes in spiders from a heavy metal pollution gradient

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Wilczek, Grazyna [Department of Animal Physiology and Ecotoxicology, University of Silesia, Bankowa 9, 40-007 Katowice (Poland); Babczynska, Agnieszka [Department of Animal Physiology and Ecotoxicology, University of Silesia, Bankowa 9, 40-007 Katowice (Poland); Augustyniak, Maria [Department of Animal Physiology and Ecotoxicology, University of Silesia, Bankowa 9, 40-007 Katowice (Poland); Migula, Pawel [Department of Animal Physiology and Ecotoxicology, University of Silesia, Bankowa 9, 40-007 Katowice (Poland)]. E-mail: migula@us.edu.pl

2004-12-01

We studied the relations between glutathione-dependent detoxifying enzymes and heavy metal burdens in the web-building spider Agelena labyrinthica (Agelenidae) and the wolf spider Pardosa lugubris (Lycosidae) from five meadow sites along a heavy metal pollution gradient. We assayed the activity of glutathione-S-transferase (GST) and glutathione peroxidases (GPOX, GSTPx), and glutathione (GSH) levels in both sexes. Except for GSH vs Pb content, we found significant correlations between GPOX and GSTPx activity and metal concentrations in females of A. labyrinthica. The highest activity of these enzymes measured in the web-building spiders was found in the individuals from the most polluted sites. In P. lugubris males significant correlations were found between GST and Pb and Zn concentrations, and between GPOX and GSTPx and the concentration of Cu. GST activity was higher in males collected from less polluted areas. Thus, detoxifying strategies against pollutants seemed to be sex-dependent. Actively hunting spiders had higher metal concentrations, maintaining lower activity of detoxifying enzymes and a lower glutathione level. - Capsule: Glutathione-linked enzyme activity in spiders from polluted areas depends on hunting strategy and sex.

Relations between metals (Zn, Pb, Cd and Cu) and glutathione-dependent detoxifying enzymes in spiders from a heavy metal pollution gradient

International Nuclear Information System (INIS)

Wilczek, Grazyna; Babczynska, Agnieszka; Augustyniak, Maria; Migula, Pawel

2004-01-01

We studied the relations between glutathione-dependent detoxifying enzymes and heavy metal burdens in the web-building spider Agelena labyrinthica (Agelenidae) and the wolf spider Pardosa lugubris (Lycosidae) from five meadow sites along a heavy metal pollution gradient. We assayed the activity of glutathione-S-transferase (GST) and glutathione peroxidases (GPOX, GSTPx), and glutathione (GSH) levels in both sexes. Except for GSH vs Pb content, we found significant correlations between GPOX and GSTPx activity and metal concentrations in females of A. labyrinthica. The highest activity of these enzymes measured in the web-building spiders was found in the individuals from the most polluted sites. In P. lugubris males significant correlations were found between GST and Pb and Zn concentrations, and between GPOX and GSTPx and the concentration of Cu. GST activity was higher in males collected from less polluted areas. Thus, detoxifying strategies against pollutants seemed to be sex-dependent. Actively hunting spiders had higher metal concentrations, maintaining lower activity of detoxifying enzymes and a lower glutathione level. - Capsule: Glutathione-linked enzyme activity in spiders from polluted areas depends on hunting strategy and sex

Glutathione system in Wolfram syndrome 1‑deficient mice.

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Porosk, Rando; Kilk, Kalle; Mahlapuu, Riina; Terasmaa, Anton; Soomets, Ursel

2017-11-01

Wolfram syndrome 1 (WS) is a rare neurodegenerative disease that is caused by mutations in the Wolfram syndrome 1 (WFS1) gene, which encodes the endoplasmic reticulum (ER) glycoprotein wolframin. The pathophysiology of WS is ER stress, which is generally considered to induce oxidative stress. As WS has a well‑defined monogenetic origin and a model for chronic ER stress, the present study aimed to characterize how glutathione (GSH), a major intracellular antioxidant, was related to the disease and its progression. The concentration of GSH and the activities of reduction/oxidation system enzymes GSH peroxidase and GSH reductase were measured in Wfs1‑deficient mice. The GSH content was lower in most of the studied tissues, and the activities of antioxidative enzymes varied between the heart, kidneys and liver tissues. The results indicated that GSH may be needed for ER stress control; however, chronic ER stress from the genetic syndrome eventually depletes the cellular GSH pool and leads to increased oxidative stress.

Glycine Increases Insulin Sensitivity and Glutathione Biosynthesis and Protects against Oxidative Stress in a Model of Sucrose-Induced Insulin Resistance

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Mohammed El-Hafidi

2018-01-01

Full Text Available Oxidative stress and redox status play a central role in the link between insulin resistance (IR and lipotoxicity in metabolic syndrome. This mechanistic link may involve alterations in the glutathione redox state. We examined the effect of glycine supplementation to diet on glutathione biosynthesis, oxidative stress, IR, and insulin cell signaling in liver from sucrose-fed (SF rats characterized by IR and oxidative stress. Our hypothesis is that the correction of glutathione levels by glycine treatment leads to reduced oxidative stress, a mechanism associated with improved insulin signaling and IR. Glycine treatment decreases the levels of oxidative stress markers in liver from SF rats and increases the concentrations of glutathione (GSH and γ-glutamylcysteine and the amount of γ-glutamylcysteine synthetase (γ-GCS, a key enzyme of GSH biosynthesis in liver from SF rats. In liver from SF rats, glycine also decreases the insulin-induced phosphorylation of insulin receptor substrate-1 (ISR-1 in serine residue and increases the phosphorylation of insulin receptor β-subunit (IR-β in tyrosine residue. Thus, supplementing diets with glycine to correct GSH deficiency and to reduce oxidative stress provides significant metabolic benefits to SF rats by improving insulin sensitivity.

Glutathione preservation during storage of rat lenses in optisol-GS and castor oil.

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Holm, Thomas; Brøgger-Jensen, Martin Rocho; Johnson, Leif; Kessel, Line

2013-01-01

Glutathione concentration in the lens decreases in aging and cataractous lenses, providing a marker for tissue condition. Experimental procedures requiring unfrozen lenses from donor banks rely on transportation in storage medium, affecting lens homeostasis and alterations in glutathione levels. The aim of the study was to examine the effects of Optisol-GS and castor oil on lens condition, determined from their ability to maintain glutathione concentrations. Rat lenses were stored in the two types of storage media at varying time intervals up to 3 days. Glutathione concentration was afterwards determined in an enzymatic detection assay, specific for both reduced and oxidized forms. Lenses removed immediately after death exhibited a glutathione concentration of 4.70±0.29 mM. In vitro stored lenses in Optisol-GS lost glutathione quickly, ending with a concentration of 0.60±0.34 mM after 3 days while castor oil stored lenses exhibited a slower decline and ended at 3 times the concentration. A group of lenses were additionally stored under post mortem conditions within the host for 6 hours before its removal. Total glutathione after 6 hours was similar to that of lenses removed immediately after death, but with altered GSH and GSSG concentrations. Subsequent storage of these lenses in media showed changes similar to those in the first series of experiments, albeit to a lesser degree. It was determined that storage in Optisol-GS resulted in a higher loss of glutathione than lenses stored in castor oil. Storage for more than 12 hours reduced glutathione to half its original concentration, and was considered unusable after 24 hours.

Glutathione preservation during storage of rat lenses in optisol-GS and castor oil.

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Thomas Holm

Full Text Available BACKGROUND: Glutathione concentration in the lens decreases in aging and cataractous lenses, providing a marker for tissue condition. Experimental procedures requiring unfrozen lenses from donor banks rely on transportation in storage medium, affecting lens homeostasis and alterations in glutathione levels. The aim of the study was to examine the effects of Optisol-GS and castor oil on lens condition, determined from their ability to maintain glutathione concentrations. METHODOLOGY/PRINCIPAL FINDINGS: Rat lenses were stored in the two types of storage media at varying time intervals up to 3 days. Glutathione concentration was afterwards determined in an enzymatic detection assay, specific for both reduced and oxidized forms. Lenses removed immediately after death exhibited a glutathione concentration of 4.70±0.29 mM. In vitro stored lenses in Optisol-GS lost glutathione quickly, ending with a concentration of 0.60±0.34 mM after 3 days while castor oil stored lenses exhibited a slower decline and ended at 3 times the concentration. A group of lenses were additionally stored under post mortem conditions within the host for 6 hours before its removal. Total glutathione after 6 hours was similar to that of lenses removed immediately after death, but with altered GSH and GSSG concentrations. Subsequent storage of these lenses in media showed changes similar to those in the first series of experiments, albeit to a lesser degree. CONCLUSIONS/SIGNIFICANCE: It was determined that storage in Optisol-GS resulted in a higher loss of glutathione than lenses stored in castor oil. Storage for more than 12 hours reduced glutathione to half its original concentration, and was considered unusable after 24 hours.

Radiosensitization of mouse skin by oxygen and depletion of glutathione

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Stevens, Graham; Joiner, Michael; Joiner, Barbara; Johns, Helen; Denekamp, Juliana

1995-01-01

Purpose: To determine the oxygen enhancement ratio (OER) and shape of the oxygen sensitization curve of mouse foot skin, the extent to which glutathione (GSH) depletion radiosensitized skin, and the dependence of such sensitization on the ambient oxygen tension. Methods and Materials: The feet of WHT mice were irradiated with single doses of 240 kVp x-rays while mice were exposed to carbogen or gases with oxygen/nitrogen mixtures containing 8-100% O 2 . The anoxic response was obtained by occluding the blood supply to the leg of anesthetized mice with a tourniquet, surrounding the foot with nitrogen, and allowing the mice to breathe 10% O 2 . Further experiments were performed to assess the efficacy of this method to obtain an anoxic response. Radiosensitivity of skin was assessed using the acute skin-reaction assay. Glutathione levels were modified using two schedules of dl-buthionine sulphoximine (BSO) and diethylmaleate (DEM), which were considered to produce extensive and intermediate levels of GSH depletion in the skin of the foot during irradiation. Results: Carbogen caused the greatest radiosensitization of skin, with a reproducible enhancement of 2.2 relative to the anoxic response. The OER of 2.2 is lower than other reports for mouse skin. This may indicate that the extremes of oxygenation were not produced, although there was no direct evidence for this. When skin radiosensitivity was plotted against the logarithm of the oxygen tension in the ambient gas, a sigmoid curve with a K value of 17-21% O 2 in the ambient gas was obtained. Depletion of GSH caused minimal radiosensitization when skin was irradiated under anoxic or well-oxygenated conditions. Radiosensitization by GSH depletion was maximal at intermediate oxygen tensions of 10-21% O 2 in the ambient gas. Increasing the extent of GSH depletion led to increasing radiosensitization, with sensitization enhancement ratios of 1.2 and 1.1, respectively, for extensive and intermediate levels of GSH

Characterization of Affinity-Purified Isoforms of Acinetobacter calcoaceticus Y1 Glutathione Transferases

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Chin-Soon Chee

2014-01-01

Full Text Available Glutathione transferases (GST were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW of 23 kDa. 2-dimensional (2-D gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5 and GST2 (pI 6.2 with identical MW. GST1 was reactive towards ethacrynic acid, hydrogen peroxide, 1-chloro-2,4-dinitrobenzene, and trans,trans-hepta-2,4-dienal while GST2 was active towards all substrates except hydrogen peroxide. This demonstrated that GST1 possessed peroxidase activity which was absent in GST2. This study also showed that only GST2 was able to conjugate GSH to isoproturon, a herbicide. GST1 and GST2 were suggested to be similar to F0KLY9 (putative glutathione S-transferase and F0KKB0 (glutathione S-transferase III of Acinetobacter calcoaceticus strain PHEA-2, respectively.

Characterization of Affinity-Purified Isoforms of Acinetobacter calcoaceticus Y1 Glutathione Transferases

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Chee, Chin-Soon; Tan, Irene Kit-Ping; Alias, Zazali

2014-01-01

Glutathione transferases (GST) were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW) of 23 kDa. 2-dimensional (2-D) gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5) and GST2 (pI 6.2) with identical MW. GST1 was reactive towards ethacrynic acid, hydrogen peroxide, 1-chloro-2,4-dinitrobenzene, and trans,trans-hepta-2,4-dienal while GST2 was active towards all substrates except hydrogen peroxide. This demonstrated that GST1 possessed peroxidase activity which was absent in GST2. This study also showed that only GST2 was able to conjugate GSH to isoproturon, a herbicide. GST1 and GST2 were suggested to be similar to F0KLY9 (putative glutathione S-transferase) and F0KKB0 (glutathione S-transferase III) of Acinetobacter calcoaceticus strain PHEA-2, respectively. PMID:24892084

Sesquiterpene lactones: Mechanism of antineoplastic activity; relationship of cellular glutathione to cytotoxicity; and disposition

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Grippo, A.A.

1987-01-01

Helenalin, a sesquiterpene lactone, inhibited the growth of P388 lymphocytic and L1210 lymphoid leukemia, and Ehrlich ascites and KB carcinoma cells. The L1210 leukemia cells were most sensitive to the cytotoxic effects of helenalin. Helenalin's antineoplastic effects were due to inhibition of DNA synthesis by suppressing the activities of enzymes involved in this biosynthetic pathway; i.e., IMP dehydrogenase, ribonucleoside diphosphate reductase, thioredoxin complex, GSH disulfide oxidoreductase and DNA polymerase α activities. The relationship of reduced glutathione (GSH) to the cytotoxic effects of helanalin was evaluated. L1210 cells, which were more sensitive to helenalin's toxicity, contained lower basal concentrations of GSH. Helenalin decreased the concentration of reduced glutathione in both L1210 and P388 leukemia cells. Concurrent administration of helanalin with agents reported to raise GSH concentrations did not substantially effect GSH levels, nor were survival times of tumor-bearing mice enhanced. Following intraperitoneal administration of 3 H-plenolin, no radioactive drug and/or metabolite was sequestered in the organs of BDF 1 mice. Approximately 50% of 3 H-plenolin and/or its metabolites were eliminated via urine while lesser amounts of radioactive drug and/or metabolites were eliminated in the feces

Preparation and Comparison of Chitosan Nanoparticles with Different Degrees of Glutathione Thiolation

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R Dinarvand

2011-12-01

Full Text Available Background: Chitosan has gained considerable attentions as a biocompatible carrier to improve delivery of active agents. Application of this vehicle in the form of nanoparticle could profit advantages of nanotechnology to increase efficacy of active agents. The purpose of this study was to provide detailed information about chitosan-glutathione (Cht-GSHnanoparticles which are gaining popularity because of their high mucoadhesive and extended drug release properties. Methods: Depolymerization of chitosan was carried out using sodium nitrite method.Glutathione was covalently attached to chitosan and the solubility of the resulting conjugates was evaluated. Nanoparticles were prepared by ionic gelation method and then the effect of glutathione immobilization on properties of nanoparticles was investigated. Results: Thiolation efficiency was higher in lower molecular weight chitosan polymers compared to unmodified chitosan nanoparticles. Cht-GSH conjugates of the same molecular weight but with different degrees of thiolation had the same hydrodynamic diameter (995± nm and surface charge (102± mV as unmodified chitosan, but comprised of a denser network structure and lower concentration. Cht-GSH nanoparticles also exhibited greater mucoadhesive strength which was less affected by ionic strength and pH of the environment. Conclusion:Thiolation improves the solubility of chitosan without any significant changes in size and charge of nanoparticles, but affects the nanogel structure.

Use of glutathione during white wine production – impact on S-off-flavors and sensory production

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Wegmann-Herr Pascal

2016-01-01

Full Text Available Recently two OIV resolutions (OENO 445-2015 and OENO 446-2015 were adopted, defining the use of glutathione (GSH up to a maximum level of 20 mg/L in must and wine. Various studies have shown the benefits of GSH addition, especially in Sauvignon blanc wines. On the other hand, the formation of hydrogen sulfide (H2S and other S-off-flavors favored by GSH addition are reported. To investigate the effect of glutathione on the color development, the sensory expression and the formation of sulfide off-flavors, Riesling, Sauvignon Blanc and Chardonnay grapes were processed under different conditions and musts were obtained with different phenolic contents. By the addition of GSH as a pure substance or the use of GSH-rich inactivated yeast preparations, the GSH concentration in the musts was varied. Bottled wines showed generally lower GSH levels than the corresponding musts. However, higher GSH concentrations after yeast aging could be determined, which may explain increased protection against oxidation during further storage. The sensory analysis after bottling showed that the fruity character of Riesling and Sauvignon blancs was enhanced at moderate GSH addition. Overuse of GSH in musts with low phenolic content, however, can lead to sensory perceptible S-off-flavors in the later wines.

Exogenous Spermidine Alleviates Low Temperature Injury in Mung Bean (Vigna radiata L. Seedlings by Modulating Ascorbate-Glutathione and Glyoxalase Pathway

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Kamrun Nahar

2015-12-01

Full Text Available The role of exogenous spermidine (Spd in alleviating low temperature (LT stress in mung bean (Vigna radiata L. cv. BARI Mung-3 seedlings has been investigated. Low temperature stress modulated the non-enzymatic and enzymatic components of ascorbate-glutathione (AsA-GSH cycle, increased H2O2 content and lipid peroxidation, which indicate oxidative damage of seedlings. Low temperature reduced the leaf relative water content (RWC and destroyed leaf chlorophyll, which inhibited seedlings growth. Exogenous pretreatment of Spd in LT-affected seedlings significantly increased the contents of non-enzymatic antioxidants of AsA-GSH cycle, which include AsA and GSH. Exogenous Spd decreased dehydroascorbate (DHA, increased AsA/DHA ratio, decreased glutathione disulfide (GSSG and increased GSH/GSSG ratio under LT stress. Activities of AsA-GSH cycle enzymes such as ascorbate peroxidase (APX, monodehydroascorbate reductase (MDHAR, dehydroascorbate reductase (DHAR and glutathione reductase (GR increased after Spd pretreatment in LT affected seedlings. Thus, the oxidative stress was reduced. Protective effects of Spd are also reflected from reduction of methylglyoxal (MG toxicity by improving glyoxalase cycle components, and by maintaining osmoregulation, water status and improved seedlings growth. The present study reveals the vital roles of AsA-GSH and glyoxalase cycle in alleviating LT injury.

The role of nuclear factor E2-Related factor 2 and uncoupling protein 2 in glutathione metabolism: Evidence from an in vivo gene knockout study

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Chen, Yanyan; Xu, Yuanyuan; Zheng, Hongzhi; Fu, Jingqi; Hou, Yongyong; Wang, Huihui; Zhang, Qiang; Yamamoto, Masayuki; Pi, Jingbo

2016-01-01

Nuclear factor E2-related factor 2 (NRF2) and uncoupling protein 2 (UCP2) are indicated to protect from oxidative stress. They also play roles in the homeostasis of glutathione. However, the detailed mechanisms are not well understood. In the present study, we found Nrf2-knockout (Nrf2-KO) mice exhibited altered glutathione homeostasis and reduced expression of various genes involved in GSH biosynthesis, regeneration, utilization and transport in the liver. Ucp2-knockout (Ucp2-KO) mice exhibited altered glutathione homeostasis in the liver, spleen and blood, as well as increased transcript of cystic fibrosis transmembrane conductance regulator in the liver, a protein capable of mediating glutathione efflux. Nrf2-Ucp2-double knockout (DKO) mice showed characteristics of both Nrf2-KO and Ucp2-KO mice. But no significant difference was observed in DKO mice when compared with Nrf2-KO or Ucp2-KO mice, except in blood glutathione levels. These data suggest that ablation of Nrf2 and Ucp2 leads to disrupted GSH balance, which could result from altered expression of genes involved in GSH metabolism. DKO may not evoke more severe oxidative stress than the single gene knockout. - Highlights: • Nrf2/Ucp2 deficiency leads to alteration of glutathione homeostasis. • Nrf2 regulates expression of genes in glutathione generation and utilization. • Ucp2 affects glutathione metabolism by regulating hepatic efflux of glutathione. • Nrf2 deficiency may not aggravate oxidative stress in Ucp2-deficient mice.

The role of nuclear factor E2-Related factor 2 and uncoupling protein 2 in glutathione metabolism: Evidence from an in vivo gene knockout study

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Chen, Yanyan [The First Affiliated Hospital, China Medical University, Shenyang, Liaoning (China); The Hamner Institutes for Health Sciences, Research Triangle Park, NC (United States); Xu, Yuanyuan, E-mail: yyxu@cmu.edu.cn [School of Public Health, China Medical University, Shenyang, Liaoning (China); Zheng, Hongzhi [The First Affiliated Hospital, China Medical University, Shenyang, Liaoning (China); The Hamner Institutes for Health Sciences, Research Triangle Park, NC (United States); Fu, Jingqi; Hou, Yongyong; Wang, Huihui [School of Public Health, China Medical University, Shenyang, Liaoning (China); Zhang, Qiang [Rollins School of Public Health, Emory University, Atlanta, GA (United States); Yamamoto, Masayuki [Graduate School of Medicine, Tohoku University, Sendai (Japan); Pi, Jingbo, E-mail: jbpi@cmu.edu.cn [School of Public Health, China Medical University, Shenyang, Liaoning (China); The Hamner Institutes for Health Sciences, Research Triangle Park, NC (United States)

2016-09-09

Nuclear factor E2-related factor 2 (NRF2) and uncoupling protein 2 (UCP2) are indicated to protect from oxidative stress. They also play roles in the homeostasis of glutathione. However, the detailed mechanisms are not well understood. In the present study, we found Nrf2-knockout (Nrf2-KO) mice exhibited altered glutathione homeostasis and reduced expression of various genes involved in GSH biosynthesis, regeneration, utilization and transport in the liver. Ucp2-knockout (Ucp2-KO) mice exhibited altered glutathione homeostasis in the liver, spleen and blood, as well as increased transcript of cystic fibrosis transmembrane conductance regulator in the liver, a protein capable of mediating glutathione efflux. Nrf2-Ucp2-double knockout (DKO) mice showed characteristics of both Nrf2-KO and Ucp2-KO mice. But no significant difference was observed in DKO mice when compared with Nrf2-KO or Ucp2-KO mice, except in blood glutathione levels. These data suggest that ablation of Nrf2 and Ucp2 leads to disrupted GSH balance, which could result from altered expression of genes involved in GSH metabolism. DKO may not evoke more severe oxidative stress than the single gene knockout. - Highlights: • Nrf2/Ucp2 deficiency leads to alteration of glutathione homeostasis. • Nrf2 regulates expression of genes in glutathione generation and utilization. • Ucp2 affects glutathione metabolism by regulating hepatic efflux of glutathione. • Nrf2 deficiency may not aggravate oxidative stress in Ucp2-deficient mice.

Inhibition of Glutathione and Thioredoxin Metabolism Enhances Sensitivity to Perifosine in Head and Neck Cancer Cells

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Andrean L. Simons

2009-01-01

Full Text Available The hypothesis that the Akt inhibitor, perifosine (PER, combined with inhibitors of glutathione (GSH and thioredoxin (Trx metabolism will induce cytotoxicity via metabolic oxidative stress in human head and neck cancer (HNSCC cells was tested. PER induced increases in glutathione disulfide (%GSSG in FaDu, Cal-27, and SCC-25 HNSCCs as well as causing significant clonogenic cell killing in FaDu and Cal-27, which was suppressed by simultaneous treatment with N-acetylcysteine (NAC. An inhibitor of GSH synthesis, buthionine sulfoximine (BSO, sensitized Cal-27 and SCC-25 cells to PER-induced clonogenic killing as well as decreased total GSH and increased %GSSG. Additionally, inhibition of thioredoxin reductase activity (TrxRed with auranofin (AUR was able to induce PER sensitization in SCC-25 cells that were initially refractory to PER. These results support the conclusion that PER induces oxidative stress and clonogenic killing in HNSCC cells that is enhanced with inhibitors of GSH and Trx metabolism.

Role of glutathione redox cycle and catalase in defense against oxidative stress induced by endosulfan in adrenocortical cells of rainbow trout (Oncorhynchus mykiss)

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Dorval, J.; Hontela, A.

2003-01-01

The role of antioxidants in maintaining the functional integrity of adrenocortical cells during in vitro exposure to endosulfan, an organochlorine pesticide, was investigated in rainbow trout (Oncorhynchus mykiss). Aminotriazole (ATA), an inhibitor of catalase (CAT), L-buthionine sulfoximine (L-BSO), an inhibitor of glutathione (GSH) synthesis, and N-acetyl cysteine (NAC), a glutathione precursor, were used to investigate the role of CAT and GSH redox cycle in protection against the adrenal toxicity of endosulfan, a pesticide that impairs cell viability (LC 50 366 μM) and cortisol secretion (EC 50 19 μM) in a concentration-related manner. Pretreatment with ATA and L-BSO enhanced the toxicity of endosulfan (LC 50 and EC 50 , respectively, 302 and 2.6 μM with ATA, 346 and 3.1 μM with L-BSO), while pretreatment with NAC had no significant effect on cell viability and increased the EC 50 of endosulfan to 51 μM. CAT activity was significantly reduced following exposure to endosulfan when cells were pretreated with ATA. Pretreatment with L-BSO significantly decreased glutathione peroxidase (GPx) activity and reduced glutathione (GSH) levels in a concentration-related manner following exposure to endosulfan, while GSH levels were significantly higher in NAC pretreated cells compared to untreated cells. Finally, pretreatment with ATA and L-BSO increased, while pretreatment with NAC decreased, lipid hydroperoxides (LOOH) levels. CAT, GPx, and GSH were identified as important antioxidants in maintaining the function and integrity of rainbow trout adrenocortical cells and ATA, L-BSO, and NAC were identified as effective modulators of CAT and GSH redox cycle. Moreover, this study suggests that the glutathione redox cycle may be more efficient than catalase in protecting adrenocortical cells against endosulfan-induced oxidative stress

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

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Hari C. Meher

2011-10-01

Full Text Available 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 μg mL–1 were measured by liquid chromatography. Resistance to root-knot nematode, Meloidogyne incognita damaging tomato and crop performance were also evaluated. SA treatment at 5.0-10.0 μg mL–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 M. incognita, nematode reproduction and thus, improved the resistance of tomato var. Pusa Ruby, but reduced crop growth and redox status. SA at 5.0 μg mL–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 M. incognita, augmented crop yield and functional food quality. SA can be applied at 5.0 μg mL–1 for metabolic engineering of tomato at transplanting to combine host-plant resistance and health benefits in formulating a strategic nematode management decision.

Glutathione in plants: an integrated overview.

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Noctor, Graham; Mhamdi, Amna; Chaouch, Sejir; Han, Yi; Neukermans, Jenny; Marquez-Garcia, Belen; Queval, Guillaume; Foyer, Christine H

2012-02-01

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. © 2011 Blackwell Publishing Ltd.

Correction of glutathione deficiency in the lower respiratory tract of HIV seropositive individuals by glutathione aerosol treatment.

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Holroyd, K J; Buhl, R; Borok, Z; Roum, J H; Bokser, A D; Grimes, G J; Czerski, D; Cantin, A M; Crystal, R G

1993-10-01

Concentrations of glutathione, a ubiquitous tripeptide with immune enhancing and antioxidant properties, are decreased in the blood and lung epithelial lining fluid of human immunodeficiency virus (HIV) seropositive individuals. Since the lung is the most common site of infection in those who progress to AIDS it is rational to consider whether it is possible to safely augment glutathione levels in the epithelial lining fluid of HIV seropositive individuals, thus potentially improving local host defence. Purified reduced glutathione was delivered by aerosol to HIV seropositive individuals (n = 14) and the glutathione levels in lung epithelial lining fluid were compared before and at one, two, and three hours after aerosol administration. Before treatment total glutathione concentrations in the epithelial lining fluid were approximately 60% of controls. After three days of twice daily doses each of 600 mg reduced glutathione, total glutathione levels in the epithelial lining fluid increased and remained in the normal range for at least three hours after treatment. Strikingly, even though > 95% of the glutathione in the aerosol was in its reduced form, the percentage of oxidised glutathione in epithelial lining fluid increased from 5% before treatment to about 40% three hours after treatment, probably reflecting the use of glutathione as an antioxidant in vivo. No adverse effects were observed. It is feasible and safe to use aerosolised reduced glutathione to augment the deficient glutathione levels of the lower respiratory tract of HIV seropositive individuals. It is rational to evaluate further the efficacy of this tripeptide in improving host defence in HIV seropositive individuals.

Glutathione-binding site of a bombyx mori theta-class glutathione transferase.

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M D Tofazzal Hossain

Full Text Available The glutathione transferase (GST superfamily plays key roles in the detoxification of various xenobiotics. Here, we report the isolation and characterization of a silkworm protein belonging to a previously reported theta-class GST family. The enzyme (bmGSTT catalyzes the reaction of glutathione with 1-chloro-2,4-dinitrobenzene, 1,2-epoxy-3-(4-nitrophenoxy-propane, and 4-nitrophenethyl bromide. Mutagenesis of highly conserved residues in the catalytic site revealed that Glu66 and Ser67 are important for enzymatic function. These results provide insights into the catalysis of glutathione conjugation in silkworm by bmGSTT and into the metabolism of exogenous chemical agents.

Glutathione-dependent extracellular ferric reductase activities in dimorphic zoopathogenic fungi

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Zarnowski, Robert; Woods, Jon P.

2009-01-01

In this study, extracellular glutathione-dependent ferric reductase (GSH-FeR) activities in different dimorphic zoopathogenic fungal species were characterized. Supernatants from Blastomyces dermatitidis, Histoplasma capsulatum, Paracoccidioides brasiliensis and Sporothrix schenckii strains grown in their yeast form were able to reduce iron enzymically with glutathione as a cofactor. Some variations in the level of reduction were noted amongst the strains. This activity was stable in acidic, neutral and slightly alkaline environments and was inhibited when trivalent aluminium and gallium ions were present. Using zymography, single bands of GSH-FeRs with apparent molecular masses varying from 430 to 460 kDa were identified in all strains. The same molecular mass range was determined by size exclusion chromatography. These data demonstrate that dimorphic zoopathogenic fungi produce and secrete a family of similar GSH-FeRs that may be involved in the acquisition and utilization of iron. Siderophore production by these and other fungi has sometimes been considered to provide a full explanation of iron acquisition in these organisms. Our work reveals an additional common mechanism that may be biologically and pathogenically important. Furthermore, while some characteristics of these enzymes such as extracellular location, cofactor utilization and large size are not individually unique, when considered together and shared across a range of fungi, they represent an important novel physiological feature. PMID:16000713

Glutathione is a highly efficient thermostabilizer of poliovirus Sabin strains.

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Abdelnabi, Rana; Delang, Leen; Neyts, Johan

2017-03-07

Glutathione (GSH) is the most abundant thiol peptide in animal cells and has a critical role in antioxidation. GSH was reported to be essential for stabilization of some enteroviruses, including poliovirus (PV), during viral morphogenesis. Here, we explored the potential use of GSH as a thermostabilizer of oral poliomyelitis vaccine (OPV) formulations. GSH significantly protected the three types of PV from heat-inactivation in a concentration-dependent manner. At a GSH concentration of 20mM, nearly complete protection was observed against heating temperatures up to 53°C for 2min.GSH also markedly protected PV1 from heat-inactivation and this up to 6 h at temperatures of 44°C and 46°C and 3 h at 48°C. The fact that GSH is naturally present at high concentration in the human body makes it an efficient candidate stabilizer for OPV formulations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Labor Augmentation with Oxytocin Decreases Glutathione Level

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Naomi Schneid-Kofman

2009-01-01

Full Text Available Objective. To compare oxidative stress following spontaneous vaginal delivery with that induced by Oxytocin augmented delivery. Methods. 98 women recruited prior to labor. 57 delivered spontaneously, while 41 received Oxytocin for augmentation of labor. Complicated deliveries and high-risk pregnancies were excluded. Informed consent was documented. Arterial cord blood gases, levels of Hematocrit, Hemoglobin, and Bilirubin were studied. Glutathione (GSH concentration was measured by a spectroscopic method. Plasma and red blood cell (RBC levels of Malondialdehyde indicated lipid peroxidation. RBC uptake of phenol red denoted cell penetrability. SPSS data analysis was used. Results. Cord blood GSH was significantly lower in the Oxytocin group (2.3±0.55 mM versus 2.55±0.55 mM, =.01. No differences were found in plasma or RBC levels of MDA or in uptake of Phenol red between the groups. Conclusion. Lower GSH levels following Oxytocin augmentation indicate an oxidative stress, though selected measures of oxidative stress demonstrate no cell damage.

Beta-amyloidolysis and glutathione in Alzheimer's disease

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Lasierra-Cirujeda J

2013-04-01

Full Text Available J Lasierra-Cirujeda,1 P Coronel,2 MJ Aza,3 M Gimeno2 1CM Hematológico SC, Logroño, La Rioja, Spain; 2Tedec-Meiji Farma, SA, Alcalá de Henares, Madrid, Spain; 3Pharmaceutical Act, Ministry of Health, Regional Government, La Rioja, Spain Abstract: In this review, we hypothesized the importance of the interaction between the brain glutathione (GSH system, the proteolytic tissue plasminogen activator (t-PA/plasminogen/plasmin system, regulated by plasminogen activator inhibitor (PAI-1, and neuroserpin in the pathogenesis of Alzheimer's disease. The histopathological characteristic hallmark that gives personality to the diagnosis of Alzheimer's disease is the accumulation of neurofibroid tangles located intracellularly in the brain, such as the protein tau and extracellular senile plaques made primarily of amyloidal substance. These formations of complex etiology are intimately related to GSH, brain protective antioxidants, and the proteolytic system, in which t-PA plays a key role. There is scientific evidence that suggests a relationship between aging, a number of neurodegenerative disorders, and the excessive production of reactive oxygen species and accompanying decreased brain proteolysis. The plasminogen system in the brain is an essential proteolytic mechanism that effectively degrades amyloid peptides ("beta-amyloidolysis" through action of the plasmin, and this physiologic process may be considered to be a means of prevention of neurodegenerative disorders. In parallel to the decrease in GSH levels seen in aging, there is also a decrease in plasmin brain activity and a progressive decrease of t-PA activity, caused by a decrease in the expression of the t-PA together with an increase of the PAI-1 levels, which rise to an increment in the production of amyloid peptides and a lesser clearance of them. Better knowledge of the GSH mechanism and cerebral proteolysis will allow us to hypothesize about therapeutic practices. Keywords: glutathione

A turn-on fluorescent sensor for the discrimination of cystein from homocystein and glutathione.

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Niu, Li-Ya; Guan, Ying-Shi; Chen, Yu-Zhe; Wu, Li-Zhu; Tung, Chen-Ho; Yang, Qing-Zheng

2013-02-14

We report a turn-on fluorescent sensor based on nitrothiophenolate boron dipyrromethene (BODIPY) derivatives for the discrimination of cystein (Cys) from homocystein (Hcy) and glutathione (GSH). The sensor was applied for detection of Cys in living cells.

Clinical study on protective of glutathione from radiation injuries in uterine cervical cancer

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Sugawa, T [Osaka City Univ. (Japan). Faculty of Medicine; Ogura, T; Kasamatsu, T; Tazaki, E; Onoda, T

1975-09-01

The protective effects of glutathione (GSH) against radiation were studied by the single, blind method in patients with carcinoma of the uterine cervix treated by radiotherapy. The background factors were same in the GSH group as in the control group. The results revealed that the occurrence of abnormal values of WBC, PLT, GOT, GPT and hematocrit in the GSH group were significantly lower than those in the control group by signed rank test, which suggests a possibility that GSH prevents these blood findings from becoming abnormal. In subjective or objective symptoms, the appearance of general lassitude was significantly reduced in the GSH group. Blood findings were studied in relation to NSD.

Possible role of glutathione in predicting radiotherapy response of cervix cancer

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Jadhav, Ganesh Krishna R.; Bhanumathi, Pullara; Devi, Pathirissery Uma; Seetharamaiah, Tattikonda; Vidyasagar, Mamudipudi S.; Rao, Kilari Koteshwer; Hospet, Chandrashekhar S.; Solomon, Johnson Gilbert R.

1998-01-01

Purpose: To see if changes in tumor/blood glutathione (GSH) levels after one fraction of radiotherapy can be correlated with the treatment response in patients with carcinoma of the uterine cervix. Methods and Materials: The study was done on 45 patients with squamous cell carcinoma of the uterine cervix, FIGO Stages IIB (17 patients) and IIIB (28 patients). Stage IIB patients received 35 Gy of cobalt-60 external radiotherapy (RT) in 16 fractions over 4 weeks with a concurrent high-dose-rate intracavitary dose of 8.5 Gy to point A once a week. Stage IIIB patients were given 45 Gy of RT in 20 fractions over 5 weeks, followed by two doses of intracavitary therapy once a week. Blood and tumor samples were collected before and after one dose of RT and GSH was estimated. Tumor response was assessed clinically at 1 month after treatment. Results: Glutathione levels in both blood and tumor showed a significant decrease after one fraction of RT, but the degree of decrease varied among patients. There was a good correlation between the extent of GSH decrease and the tumor response. All patients who had complete response (CR) (seven Stage IIB and eight Stage IIIB) showed ≥70% decrease in both tumor and blood GSH, while those who had <50% regression (NR) (five Stage IIB and 13 Stage IIIB) showed <50% decrease in GSH. The partial responders recorded an intermediate level (50-70%) of depletion in blood and tumor GSH. Conclusions: The results indicate that the changes in tumor/blood GSH levels after one fraction of RT could serve as an index of tumor response to therapy and may help in identifying radioresistant tumors, at least in the case of cervix carcinoma

A SERS protocol as a potential tool to access 6-mercaptopurine release accelerated by glutathione-S-transferase.

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Wang, Ying; Sun, Jie; Yang, Qingran; Lu, Wenbo; Li, Yan; Dong, Jian; Qian, Weiping

2015-11-21

The developed method for monitoring GST, an important drug metabolic enzyme, could greatly facilitate researches on relative biological fields. In this work, we have developed a SERS technique to monitor the absorbance behaviour of 6-mercaptopurine (6-MP) and its glutathione-S-transferase (GST)-accelerated glutathione (GSH)-triggered release behaviour on the surface of gold nanoflowers (GNFs), using the GNFs as excellent SERS substrates. The SERS signal was used as an indicator of absorbance or release of 6-MP on the gold surface. We found that GST can accelerate GSH-triggered release behaviour of 6-MP from the gold surface. We speculated that GST catalyzes nucleophilic GSH to competitively bind with the electrophilic substance 6-MP. Experimental results have proved that the presented SERS protocol can be utilized as an effective tool for accessing the release of anticancer drugs.

The role of glutathione in DNA damage by potassium bromate in vitro.

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Parsons, J L; Chipman, J K

2000-07-01

We have investigated the role of reduced glutathione (GSH) in the genetic toxicity of the rodent renal carcinogen potassium bromate (KBrO(3)). A statistically significant increase in the concentration of 8-oxodeoxyguanosine (8-oxodG) relative to deoxyguanosine was measured following incubation of calf thymus DNA with KBrO(3) and GSH or N-acetylcysteine (NACys). This was dependent on these thiols and was associated with the loss of GSH and production of oxidized glutathione. A short-lived (potassium chlorate (KClO(3)) or potassium iodate (KIO(3)) were used instead of KBrO(3), though GSH depletion also occurred with KIO(3), but not with KClO(3). Other reductants and thiols in combination with KBrO(3) did not cause a significant increase in DNA oxidation. DNA strand breakage was also induced by KBrO(3) in human white blood cells (5 mM) and rat kidney epithelial cells (NRK-52E, 1.5 mM). This was associated with an apparent small depletion of thiols in NRK-52E cells at 15 min and with an elevation of 8-oxodG at a delayed time of 24 h. Depletion of intra-cellular GSH by diethylmaleate in human lymphocytes decreased the amount of strand breakage induced by KBrO(3). Extracellular GSH, however, protected against DNA strand breakage by KBrO(3), possibly due to the inability of the reactive product to enter the cell. In contrast, membrane-permeant NACys enhanced KBrO(3)-induced DNA strand breakage in these cells. DNA damage by KBrO(3) is therefore largely dependent on access to intracellular GSH.

Toll-Like Receptor 4 Reduces Oxidative Injury via Glutathione Activity in Sheep

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Shoulong Deng

2016-01-01

Full Text Available Toll-like receptor 4 (TLR4 is an important sensor of Gram-negative bacteria and can trigger activation of the innate immune system. Increased activation of TLR4 can lead to the induction of oxidative stress. Herein, the pathway whereby TLR4 affects antioxidant activity was studied. In TLR4-overexpressing sheep, TLR4 expression was found to be related to the integration copy number when monocytes were challenged with lipopolysaccharide (LPS. Consequently, production of malondialdehyde (MDA was increased, which could increase the activation of prooxidative stress enzymes. Meanwhile, activation of an antioxidative enzyme, glutathione peroxidase (GSH-Px, was increased. Real-time PCR showed that expression of activating protein-1 (AP-1 and the antioxidative-related genes was increased. By contrast, the expression levels of superoxide dismutase 1 (SOD1 and catalase (CAT were reduced. In transgenic sheep, glutathione (GSH levels were dramatically reduced. Furthermore, transgenic sheep were intradermally injected with LPS in each ear. The amounts of inflammatory infiltrates were correlated with the number of TLR4 copies that were integrated in the genome. Additionally, the translation of γ-glutamylcysteine synthetase (γ-GCS was increased. Our findings indicated that overexpression of TLR4 in sheep could ameliorate oxidative injury through GSH secretion that was induced by LPS stimulation. Furthermore, TLR4 promoted γ-GCS translation through the AP-1 pathway, which was essential for GSH synthesis.

Corneal endothelial glutathione after photodynamic change

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Hull, D.S.; Riley, M.V.; Csukas, S.; Green, K.

1982-01-01

Rabbit corneal endothelial cells perfused with 5 X 10(-6)M rose bengal and exposed to incandescent light demonstrated no alteration of either total of or percent oxidized glutathione after 1 hr. Addition of 5400 U/ml catalase to the perfusing solution had no effect on total glutathione levels but caused a marked reduction in percent oxidized glutathione in corneas exposed to light as well as in those not exposed to light. Substitution of sucrose for glucose in the perfusing solution had no effect on total or percent oxidized glutathione. Perfusion of rabbit corneal endothelium with 0.5 mM chlorpromazine and exposure to ultraviolet (UV) light resulted in no change in total glutathione content. A marked reduction in percent oxidized glutathione occurred, however, in corneas perfused with 0.5 mM chlorpromazine both in the presence and absence of UV light. It is concluded that photodynamically induced swelling of corneas is not the result of a failure of the glutathione redox system

Glutathione-induced drought stress tolerance in mung bean: coordinated roles of the antioxidant defence and methylglyoxal detoxification systems

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Nahar, Kamrun; Hasanuzzaman, Mirza; Alam, Md. Mahabub; Fujita, Masayuki

2015-01-01

Drought is considered one of the most acute environmental stresses presently affecting agriculture. We studied the role of exogenous glutathione (GSH) in conferring drought stress tolerance in mung bean (Vigna radiata L. cv. Binamoog-1) seedlings by examining the antioxidant defence and methylglyoxal (MG) detoxification systems and physiological features. Six-day-old seedlings were exposed to drought stress (−0.7 MPa), induced by polyethylene glycol alone and in combination with GSH (1 mM) for 24 and 48 h. Drought stress decreased seedling dry weight and leaf area; resulted in oxidative stress as evidenced by histochemical detection of hydrogen peroxide (H2O2) and O2⋅− in the leaves; increased lipid peroxidation (malondialdehyde), reactive oxygen species like H2O2 content and O2⋅− generation rate and lipoxygenase activity; and increased the MG level. Drought decreased leaf succulence, leaf chlorophyll and relative water content (RWC); increased proline (Pro); decreased ascorbate (AsA); increased endogenous GSH and glutathione disulfide (GSSG) content; decreased the GSH/GSSG ratio; increased ascorbate peroxidase and glutathione S-transferase activities; and decreased the activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and catalase. The activities of glyoxalase I (Gly I) and glyoxalase II (Gly II) increased due to drought stress. In contrast to drought stress alone, exogenous GSH enhanced most of the components of the antioxidant and glyoxalase systems in drought-affected mung bean seedlings at 24 h, but GSH did not significantly affect AsA, Pro, RWC, leaf succulence and the activities of Gly I and DHAR after 48 h of stress. Thus, exogenous GSH supplementation with drought significantly enhanced the antioxidant components and successively reduced oxidative damage, and GSH up-regulated the glyoxalase system and reduced MG toxicity, which played a significant role in improving the physiological features and drought

Novel method for measurement of glutathione kinetics in neonates using liquid chromatography coupled to isotope ratio mass spectrometry

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Schierbeek, Henk; te Braake, Frans; Godin, Jean-Philippe; Fay, Laurent-Bernard; van Goudoever, Johannes B.

2007-01-01

A novel analytical method using liquid chromatography coupled to isotope ratio mass spectrometry (LC/IRMS) was developed for measuring the fractional synthesis rate (FSR) of glutathione (GSH) in neonates after infusion of [1-(13)C]-glycine as a tracer. After transformation of GSH into GSSG, its

Structural Understanding of the Glutathione-dependent Reduction Mechanism of Glutathionyl-Hydroquinone Reductases*

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Green, Abigail R.; Hayes, Robert P.; Xun, Luying; Kang, ChulHee

2012-01-01

Glutathionyl-hydroquinone reductases (GS- HQRs) are a newly identified group of glutathione transferases, and they are widely distributed in bacteria, halobacteria, fungi, and plants. GS-HQRs catalyze glutathione (GSH)-dependent reduction of glutathionyl-hydroquinones (GS-hydroquinones) to hydroquinones. GS-hydroquinones can be spontaneously formed from benzoquinones reacting with reduced GSH via Michael addition, and GS-HQRs convert the conjugates to hydroquinones. In this report we have determined the structures of two bacterial GS-HQRs, PcpF of Sphingobium chlorophenolicum and YqjG of Escherichia coli. The two structures and the previously reported structure of a fungal GS-HQR shared many features and displayed complete conservation for all the critical residues. Furthermore, we obtained the binary complex structures with GS-menadione, which in its reduced form, GS-menadiol, is a substrate. The structure revealed a large H-site that could accommodate various substituted hydroquinones and a hydrogen network of three Tyr residues that could provide the proton for reductive deglutathionylation. Mutation of the Tyr residues and the position of two GSH molecules confirmed the proposed mechanism of GS-HQRs. The conservation of GS-HQRs across bacteria, halobacteria, fungi, and plants potentiates the physiological role of these enzymes in quinone metabolism. PMID:22955277

Reduction of intracellular glutathione content and radiosensitivity

International Nuclear Information System (INIS)

Vos, O.; Schans, G.P. van der; Roos-Verheij, W.S.D.

1986-05-01

The intracellular glutathione (GSH) content in HeLa, CHO and V79 cells was reduced by incubating the cells in growth medium containing buthionine sulfoximine (BSO) or diethyl maleate (DEM). Clonogenicity, single strand DNA breaks (ssb) and double strand DNA breaks (dsb) were used as criteria for radiation induced damage after X- or γ irradiation. In survival experiments DEM gave a slightly larger sensitization although it gave a smaller reduction of the intracellular GSH. In general, sensitization was larger for dsb than for ssb, also the reduction of the OER was generally larger for dsb than for ssb. This may be due to the higher dose rate in case of dsb experiments resulting in a higher rate of radiochemical oxygen consumption. In general, no effect was found on post-irradiation repair of ssb and dsb. (Auth.)

Reduction of intracellular glutathione content and radiosensitivity

International Nuclear Information System (INIS)

Vos, O.; Schans, G.P. van der; Roos-Verheij, W.S.D.

1986-01-01

The intracellular glutathione (GSH) content of HeLa, CHO and V79 cells was reduced by incubating the cells in growth medium containing buthionine sulphoximine or diethyl maleate (DEM). Clonogenicity, single-strand DNA breaks (ssb) and double-strand DNA breaks (dsb) were used as criteria for radiation-induced damage after X- or γ-irradiation. In survival experiments, DEM gave a slightly larger sensitization although it gave a smaller reduction of the intracellular GSH. In general, sensitization was larger for dsb than for ssb, also the reduction of the o.e.r. was generally larger for dsb than for ssb. This may be due to the higher dose rate in case of dsb experiments resulting in a higher rate of radiochemical oxygen consumption. In general, no effect was found on post-irradiation repair of ssb and dsb. (author)

Simple and Sensitive Colorimetric Assay for Pb2+ Based on Glutathione Protected Ag Nanoparticles by Salt Amplification.

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Chen, Zhang; Li, Huidong; Chu, Lin; Liu, Chenbin; Luo, Shenglian

2015-02-01

A simple and sensitive colorimetric assay for Pb2+ detection has been reported using glutathione protected silver nanoparticles (AgNPs) by salt amplification. The naked AgNPs aggregate under the influence of salt. Glutathione (GSH) can bind to AgNPs via Ag-S bond, helping AgNPs to against salt-induced aggregation. However, GSH binding to AgNPs can be compromised by the interaction between Pb2+ and GSH. As a result, Pb2+-mediated aggregation of AgNPs under the influence of salt is reflected by the UV-Visible spectrum, and the qualitative and quantitative detection for Pb2+ is accomplished, with the detection range 0.5-4 µM and a detection limit of 0.5 µM. At the same time, Pb2+ in real water sample is detected. Furthermore, the high selectivity and low cost of the assay means it is promising for enviromental applications.

The evolution of glutathione metabolism in phototrophic microorganisms

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Fahey, Robert C.; Buschbacher, Ralph M.; Newton, Gerald L.

1988-01-01

The low molecular weight thiol composition of a variety of phototropic microorganisms is examined in order to ascertain how evolution of glutathione (GSH) production is related to the evolution of oxygenic photosynthesis. Cells were extracted in the presence of monobromobimane (mBBr) to convert thiols (RSH) to fluorescent derivatives (RSmB) which were analyzed by high performance liquid chromatography (HPLC). Significant levels of GSH were not found in green sulfur bacteria. Substantial levels were present in purple bacteria, cyanobacteria, and eukaryotic algae. Other thiols measured included cysteine, gamma-glutamylcysteine, thiosulfate, coenzyme A, and sulfide. Many of the organisms also exhibited a marked ability to reduce mBBr to syn-(methyl,methyl)bimane, an ability which was quenched by treatment with 2-pyridyl disulfide or 5,5 prime-bisdithio - (2-nitrobenzoic acid) prior to reaction with mBBr. These observations indicate the presence of a reducing system capable of electron transfer to mBBr and reduction of reactive disulfides. The distribution of GSH in phototropic eubacteria indicates that GSH synthesis evolved at or around the time that oxygenic photosynthesis evolved.

Changes of reduced glutathion, glutathion reductase, and glutathione peroxidase after radiation in guinea pigs

International Nuclear Information System (INIS)

Erden, M.; Bor, N.M.

1984-01-01

In this series of experiments the protective action of reduced glutathion due to ionizing radiation has been studied. In the experimental group 18 guinea pigs were exposed to successive radiations of 150 rad 3 or 4 days apart. Total dose given amounted to 750 rad which is the LD50 for guinea pigs. Blood samples were taken 30 min after each exposure. The control series were sham radiated but otherwise treated identically. The cells of the removed blood samples were separated by centrifugation and were subjected to the reduced glutathion stability test. GSSGR, GPer, and LDH enzyme activities were also measured of which the latter served as a marked enzyme. It was found that LDH did not show any alteration after radiation. The reduced glutathion stability test showed a consistent but minor reduction (P greater than 0.05), in the experimental group. GSSGR enzyme activity on the other hand was reduced significantly (from 176.48 +/- 11.32 to 41.34 +/- 1.17 IU/ml of packed erythrocytes, P less than 0.001) in the same group. GPer activity showed a consistent but minor elevation during the early phase of the experimental group. It was later increased significantly beginning after 600 rad total radiation on the fourth session (P less than 0.050)

Chronic aspartame intake causes changes in the trans-sulphuration pathway, glutathione depletion and liver damage in mice

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Isabela Finamor

2017-04-01

Full Text Available No-caloric sweeteners, such as aspartame, are widely used in various food and beverages to prevent the increasing rates of obesity and diabetes mellitus, acting as tools in helping control caloric intake. Aspartame is metabolized to phenylalanine, aspartic acid, and methanol. Our aim was to study the effect of chronic administration of aspartame on glutathione redox status and on the trans-sulphuration pathway in mouse liver. Mice were divided into three groups: control; treated daily with aspartame for 90 days; and treated with aspartame plus N-acetylcysteine (NAC. Chronic administration of aspartame increased plasma alanine aminotransferase (ALT and aspartate aminotransferase activities and caused liver injury as well as marked decreased hepatic levels of reduced glutathione (GSH, oxidized glutathione (GSSG, γ-glutamylcysteine ​​(γ-GC, and most metabolites of the trans-sulphuration pathway, such as cysteine, S-adenosylmethionine (SAM, and S-adenosylhomocysteine ​​(SAH. Aspartame also triggered a decrease in mRNA and protein levels of the catalytic subunit of glutamate cysteine ligase (GCLc and cystathionine γ-lyase, and in protein levels of methionine adenosyltransferase 1A and 2A. N-acetylcysteine prevented the aspartame-induced liver injury and the increase in plasma ALT activity as well as the decrease in GSH, γ-GC, cysteine, SAM and SAH levels and GCLc protein levels. In conclusion, chronic administration of aspartame caused marked hepatic GSH depletion, which should be ascribed to GCLc down-regulation and decreased cysteine levels. Aspartame triggered blockade of the trans-sulphuration pathway at two steps, cystathionine γ-lyase and methionine adenosyltransferases. NAC restored glutathione levels as well as the impairment of the trans-sulphuration pathway.

Chronic aspartame intake causes changes in the trans-sulphuration pathway, glutathione depletion and liver damage in mice.

Science.gov (United States)

Finamor, Isabela; Pérez, Salvador; Bressan, Caroline A; Brenner, Carlos E; Rius-Pérez, Sergio; Brittes, Patricia C; Cheiran, Gabriele; Rocha, Maria I; da Veiga, Marcelo; Sastre, Juan; Pavanato, Maria A

2017-04-01

No-caloric sweeteners, such as aspartame, are widely used in various food and beverages to prevent the increasing rates of obesity and diabetes mellitus, acting as tools in helping control caloric intake. Aspartame is metabolized to phenylalanine, aspartic acid, and methanol. Our aim was to study the effect of chronic administration of aspartame on glutathione redox status and on the trans-sulphuration pathway in mouse liver. Mice were divided into three groups: control; treated daily with aspartame for 90 days; and treated with aspartame plus N-acetylcysteine (NAC). Chronic administration of aspartame increased plasma alanine aminotransferase (ALT) and aspartate aminotransferase activities and caused liver injury as well as marked decreased hepatic levels of reduced glutathione (GSH), oxidized glutathione (GSSG), γ-glutamylcysteine ​​(γ-GC), and most metabolites of the trans-sulphuration pathway, such as cysteine, S-adenosylmethionine (SAM), and S-adenosylhomocysteine ​​(SAH). Aspartame also triggered a decrease in mRNA and protein levels of the catalytic subunit of glutamate cysteine ligase (GCLc) and cystathionine γ-lyase, and in protein levels of methionine adenosyltransferase 1A and 2A. N-acetylcysteine prevented the aspartame-induced liver injury and the increase in plasma ALT activity as well as the decrease in GSH, γ-GC, cysteine, SAM and SAH levels and GCLc protein levels. In conclusion, chronic administration of aspartame caused marked hepatic GSH depletion, which should be ascribed to GCLc down-regulation and decreased cysteine levels. Aspartame triggered blockade of the trans-sulphuration pathway at two steps, cystathionine γ-lyase and methionine adenosyltransferases. NAC restored glutathione levels as well as the impairment of the trans-sulphuration pathway. Copyright © 2017. Published by Elsevier B.V.

Nucleation behavior of glutathione polymorphs in water

International Nuclear Information System (INIS)

Chen, Zhi; Dang, Leping; Li, Shuai; Wei, Hongyuan

2013-01-01

Nucleation behavior of glutathione (GSH) polymorphs in water was investigated by experimental method combined with classical nucleation theory. The solubility of α and β forms GSH in water at different temperatures, and the nucleation induction period at various supersaturations and temperatures were determined experimentally. The results show that, in a certain range of supersaturation, the nucleation of β form predominates at relatively higher temperature, while α form will be obtained at lower temperature. The nucleation kinetics parameters of α and β form were then calculated. To understand the crucial role of temperature on crystal forms, “hypothetic” nucleation parameters of β form at 283.15 K were deduced based on extrapolation method. The results show that the interfacial tension, critical free energy, critical nucleus radius and nucleus number of α form are smaller than that of β form in the same condition at 283.15 K, which implies that α form nucleates easier than β form at low temperature. This work may be useful for the control and optimization of GSH crystallization process in industry

Expression Patterns of Genes Involved in Ascorbate-Glutathione Cycle in Aphid-Infested Maize (Zea mays L.) Seedlings.

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Sytykiewicz, Hubert

2016-02-23

Reduced forms of ascorbate (AsA) and glutathione (GSH) are among the most important non-enzymatic foliar antioxidants in maize (Zea mays L.). The survey was aimed to evaluate impact of bird cherry-oat aphid (Rhopalosiphum padi L.) or grain aphid (Sitobion avenae F.) herbivory on expression of genes related to ascorbate-glutathione (AsA-GSH) cycle in seedlings of six maize varieties (Ambrozja, Nana, Tasty Sweet, Touran, Waza, Złota Karłowa), differing in resistance to the cereal aphids. Relative expression of sixteen maize genes encoding isoenzymes of ascorbate peroxidase (APX1, APX2, APX3, APX4, APX5, APX6, APX7), monodehydroascorbate reductase (MDHAR1, MDHAR2, MDHAR3, MDHAR4), dehydroascorbate reductase (DHAR1, DHAR2, DHAR3) and glutathione reductase (GR1, GR2) was quantified. Furthermore, effect of hemipterans' attack on activity of APX, MDHAR, DHAR and GR enzymes, and the content of reduced and oxidized ascorbate and glutathione in maize plants were assessed. Seedling leaves of more resistant Z. mays varieties responded higher elevations in abundance of target transcripts. In addition, earlier and stronger aphid-triggered changes in activity of APX, MDHAR, DHAR and GR enzymes, and greater modulations in amount of the analyzed antioxidative metabolites were detected in foliar tissues of highly resistant Ambrozja genotype in relation to susceptible Tasty Sweet plants.

Pyridine nucleotide cycling and control of intracellular redox state in relation to poly (ADP-ribose) polymerase activity and nuclear localization of glutathione during exponential growth of Arabidopsis cells in culture.

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Pellny, Till K; Locato, Vittoria; Vivancos, Pedro Diaz; Markovic, Jelena; De Gara, Laura; Pallardó, Federico V; Foyer, Christine H

2009-05-01

Pyridine nucleotides, ascorbate and glutathione are major redox metabolites in plant cells, with specific roles in cellular redox homeostasis and the regulation of the cell cycle. However, the regulation of these metabolite pools during exponential growth and their precise functions in the cell cycle remain to be characterized. The present analysis of the abundance of ascorbate, glutathione, and pyridine nucleotides during exponential growth of Arabidopsis cells in culture provides evidence for the differential regulation of each of these redox pools. Ascorbate was most abundant early in the growth cycle, but glutathione was low at this point. The cellular ascorbate to dehydroascorbate and reduced glutathione (GSH) to glutathione disulphide ratios were high and constant but the pyridine nucleotide pools were largely oxidized over the period of exponential growth and only became more reduced once growth had ceased. The glutathione pool increased in parallel with poly (ADP-ribose) polymerase (PARP) activities and with increases in the abundance of PARP1 and PARP2 mRNAs at a time of high cell cycle activity as indicated by transcriptome information. Marked changes in the intracellular partitioning of GSH between the cytoplasm and nucleus were observed. Extension of the exponential growth phase by dilution or changing the media led to increases in the glutathione and nicotinamide adenine dinucleotide, oxidized form (NAD)-plus-nicotinamide adenine dinucleotide, reduced form (NADH) pools and to higher NAD/NADH ratios but the nicotinamide adenine dinucleotide phosphate, oxidized form (NADP)-plus-nicotinamide adenine dinucleotide phosphate, reduced form (NADPH) pool sizes, and NAPD/NADPH ratios were much less affected. The ascorbate, glutathione, and pyridine nucleotide pools and PARP activity decreased before the exponential growth phase ended. We conclude that there are marked changes in intracellular redox state during the growth cycle but that redox homeostasis is

Impedimetric Urea Biosensor Based on Modified Gold Electrode with Urease Immobilized on Glutathione Layer

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Houcine BARHOUMI

2014-05-01

Full Text Available In this work, a glutathione (GSH modified gold microelectrode was used for the covalent immobilization of urease biomolecules via the glutaraldehyde-coupling agent. The self- assembled monolayers (SAMs onto the gold surface was investigated by using the electrochemical impedance spectroscopy measurements (EIS. Before urease grafting, a significant interaction was noticed between urea and the glutathione layer by forming hydrogen bonds. The H-NMR analysis was carried out to highlight the possibility of having a covalent link between urea and the GSH deposited layer. In addition, contact angle measurements were carried out to determine the hydrophobic/hydrophilic feature of the modified gold surface electrode. After urease immobilization a stable and high sensitive impedimetric urea biosensors was obtained with a sensitivity of 8.73´10- 8 W-1mM-1 for the low concentrations range and a sensitivity of 7.03´10-9 W-1mM-1 for the high concentrations range.

Combined radiation-protective and radiation-sensitizing agents. III. Radiosensitization by misonidazole as a function of concentrations of endogenous glutathione or exogenous thiols

International Nuclear Information System (INIS)

Koch, C.J.; Stobbe, C.C.; Baer, K.A.

1986-01-01

Radiosensitization of V79 Chinese hamster fibroblasts by 0.5 mM misonidazole is a smooth function of endogenous glutathione (GSH) levels as modulated upwards by pre-incubation in medium containing cysteamine, or downwards by pre-incubation in medium containing buthionine sulfoximine. The enhancement ratio (radiation sensitivity in nitrogen/radiation sensitivity in nitrogen +/- sensitizer or thiol) varies from 1.3 at 12 mM to 2.25 at less than 0.1 mM endogenous GSH. The enhanced radiosensitivity of thiol-depleted hypoxic cells is reversed when exogenous thiols are added, and for equivalent ER, the exogenous thiol concentrations are much lower than the endogenous GSH concentrations. Measurement of intracellular drug concentrations amplified rather than diminished the above discrepancy, since intracellular concentrations of cysteamine were lower and glutathione much lower than the extracellular concentrations. Three possible explanations are addressed: an external membrane component of damage is involved, long-range protection to DNA target radicals is possible from outside the cell (e.g., donation of electrons), and (c) endogenous glutathione is not in a free or exchangeable state (e.g., bound)

[Effects of melaxen and valdoxan on the activity of glutathione antioxidant system and NADPH-producing enzymes in rat heart under experimental hyperthyroidism conditions].

Science.gov (United States)

Gorbenko, M V; Popova, T N; Shul'gin, K K; Popov, S S

2013-01-01

The effects of melaxen and valdoxan on the activity of glutathione antioxidant system and some NADPH-producing enzymes have been studied under conditions of experimental hyperthyroidism in rat heart. Under the action of these drugs, reduced glutathione (GSH) content increased as compared to values observed under the conditions of pathology. It has been established that the activities of glutathione reductase (GR), glutathione peroxidase (GP), glucose-6-phosphate dehydrogenase, and NADP isocitrate dehydrogenase (increased under pathological conditions) change toward the intact control values upon the introduction of both drugs. The influence of melaxen and valdoxan, capable of producing antioxidant effect, leads apparently to the inhibition of free-radical oxidation processes and, as a consequence, the reduction of mobilization degree of the glutathione antioxidant system.

Impacts of glutathione Maillard reaction products on sensory characteristics and consumer acceptability of beef soup.

Science.gov (United States)

Hong, J H; Jung, D W; Kim, Y S; Lee, S M; Kim, K O

2010-10-01

The sensory characteristics and consumer acceptability of beef soup with added glutathione Maillard reaction products (GMRPs) were investigated to examine the effects of the GMRPs on beef-soup flavor compared to soups made with glutathione (GSH) and monosodium glutamate (MSG), a control (CON), or a control soup made with 150% beef content (CON150). The sensory characteristics of the beef soups were examined by descriptive analysis. The overall acceptabilities of the beef soups were rated by consumers. Principal component analysis was performed on descriptive data as explanatory variables with overall acceptability as a supplementary variable to observe the relationships between the descriptive data and consumer acceptability, as well as the relationships between the beef-soup samples and their sensory attributes. The samples containing GMRPs had "beef flavor" that was stronger than the CON and MSG samples, and comparable to that of the GSH sample and CON150. The GMRP samples had stronger "green onion flavor,"garlic flavor," and "boiled egg white flavor" than the other samples. The beef soup containing MSG was preferred to CON, CON150, and GSH. The samples with GMRPs were least favored because of their pronounced metallic and astringent notes. The results of this study imply the feasibility of GMRPs as a flavor enhancer since the soups containing these compounds showed more complex flavor profiles than GSH. However, future studies are required to optimize the MR conditions that produce GMRPs without undesirable characteristics. Practical Application: This study examined the practicability of the Maillard reaction products between glutathione (GSH) and glucose (GP) or fructose (FP) as a flavor enhancer by investigating the sensory characteristics and consumer acceptability evoked by them in a beef-soup system. This study helps flavor and food industry to develop a new flavor enhancer by providing practical information, such as beef flavor-enhancing effect of FP and

Synthèse d’un dérivé du fragment glutamique du glutathion

OpenAIRE

CHIBI, Nadjet

2016-01-01

Le glutathion (GSH) est un tripeptide, formé par la condensation d'acide glutamique, de cystéine et de glycine, connu pour ses propriétés thérapeutiques intéressantes : Anti-vieillissement. Prévention et lutte contre le cancer. Prévention et réduction des symptômes des maladies dégénératives. Prévention et contrôle de l'artériosclérose. Diminution des effets dégénérateurs du diabète. Mais puisqu’il est impossible d’avoir le glutathion, car il est instable en deh...

Prenatal methylmercury exposure hampers glutathione antioxidant system ontogenesis and causes long-lasting oxidative stress in the mouse brain

International Nuclear Information System (INIS)

Stringari, James; Nunes, Adriana K.C.; Franco, Jeferson L.; Bohrer, Denise; Garcia, Solange C.; Dafre, Alcir L.; Milatovic, Dejan; Souza, Diogo O.; Rocha, Joao B.T.; Aschner, Michael; Farina, Marcelo

2008-01-01

During the perinatal period, the central nervous system (CNS) is extremely sensitive to metals, including methylmercury (MeHg). Although the mechanism(s) associated with MeHg-induced developmental neurotoxicity remains obscure, several studies point to the glutathione (GSH) antioxidant system as an important molecular target for this toxicant. To extend our recent findings of MeHg-induced GSH dyshomeostasis, the present study was designed to assess the developmental profile of the GSH antioxidant system in the mouse brain during the early postnatal period after in utero exposure to MeHg. Pregnant mice were exposed to different doses of MeHg (1, 3 and 10 mg/l, diluted in drinking water, ad libitum) during the gestational period. After delivery, pups were killed at different time points - postnatal days (PND) 1, 11 and 21 - and the whole brain was used for determining biochemical parameters related to the antioxidant GSH system, as well as mercury content and the levels of F 2 -isoprostane. In control animals, cerebral GSH levels significantly increased over time during the early postnatal period; gestational exposure to MeHg caused a dose-dependent inhibition of this developmental event. Cerebral glutathione peroxidase (GPx) and glutathione reductase (GR) activities significantly increased over time during the early postnatal period in control animals; gestational MeHg exposure induced a dose-dependent inhibitory effect on both developmental phenomena. These adverse effects of prenatal MeHg exposure were corroborated by marked increases in cerebral F 2 -isoprostanes levels at all time points. Significant negative correlations were found between F 2 -isoprostanes and GSH, as well as between F 2 -isoprostanes and GPx activity, suggesting that MeHg-induced disruption of the GSH system maturation is related to MeHg-induced increased lipid peroxidation in the pup brain. In utero MeHg exposure also caused a dose-dependent increase in the cerebral levels of mercury at

Glutathione-deficient Plasmodium berghei parasites exhibit growth delay and nuclear DNA damage.

Science.gov (United States)

Padín-Irizarry, Vivian; Colón-Lorenzo, Emilee E; Vega-Rodríguez, Joel; Castro, María Del R; González-Méndez, Ricardo; Ayala-Peña, Sylvette; Serrano, Adelfa E

2016-06-01

Plasmodium parasites are exposed to endogenous and exogenous oxidative stress during their complex life cycle. To minimize oxidative damage, the parasites use glutathione (GSH) and thioredoxin (Trx) as primary antioxidants. We previously showed that disruption of the Plasmodium berghei gamma-glutamylcysteine synthetase (pbggcs-ko) or the glutathione reductase (pbgr-ko) genes resulted in a significant reduction of GSH in intraerythrocytic stages, and a defect in growth in the pbggcs-ko parasites. In this report, time course experiments of parasite intraerythrocytic development and morphological studies showed a growth delay during the ring to schizont progression. Morphological analysis shows a significant reduction in size (diameter) of trophozoites and schizonts with increased number of cytoplasmic vacuoles in the pbggcs-ko parasites in comparison to the wild type (WT). Furthermore, the pbggcs-ko mutants exhibited an impaired response to oxidative stress and increased levels of nuclear DNA (nDNA) damage. Reduced GSH levels did not result in mitochondrial DNA (mtDNA) damage or protein carbonylations in neither pbggcs-ko nor pbgr-ko parasites. In addition, the pbggcs-ko mutant parasites showed an increase in mRNA expression of genes involved in oxidative stress detoxification and DNA synthesis, suggesting a potential compensatory mechanism to allow for parasite proliferation. These results reveal that low GSH levels affect parasite development through the impairment of oxidative stress reduction systems and damage to the nDNA. Our studies provide new insights into the role of the GSH antioxidant system in the intraerythrocytic development of Plasmodium parasites, with potential translation into novel pharmacological interventions. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Quantitative detection of nitroxyl upon trapping with glutathione and labeling with a specific fluorogenic reagent.

Science.gov (United States)

Johnson, Gail M; Chozinski, Tyler J; Salmon, Debra J; Moghaddam, Alan D; Chen, Hsin Chih; Miranda, Katrina M

2013-10-01

Donors of nitroxyl (HNO) have shown promise for treatment of stroke, heart failure, alcoholism and cancer. However, comparing the pharmacological capacities of various donors is difficult without first quantifying the amount of HNO released from each donor. Detection and quantitation of HNO has been complicated by the rapid self-consumption of HNO through irreversible dimerization, poor selectivity of trapping agents against other nitrogen oxides, and/or low sensitivity towards HNO. Here, an assay is described for the trapping of HNO by glutathione (GSH) followed by labeling of GSH with the fluorogenic agent, naphthalene-2,3-dicarboxaldehyde (NDA), and subsequent quantitation by fluorescence difference. The newly developed assay was used to validate the pH-dependence of HNO release from isopropylamine NONOate (IPA/NO), which is a dual donor of HNO and NO at physiological pH. Furthermore, varied assay conditions were utilized to suggest the ratios of the products of the reaction of GSH with HNO. At intracellular concentrations of GSH, the disulfide (GSSG) was the major product, but significant concentrations of glutathione sulfinamide (GS(O)NH₂) were also detected. This suggests that GS(O)NH₂, which is a selective biomarker of HNO, may be produced in concentrations that are amenable to in vivo analysis. Copyright © 2013 Elsevier Inc. All rights reserved.

Cytotoxic effects of S-(dimethylarsino)-glutathione: A putative intermediate metabolite of inorganic arsenicals

International Nuclear Information System (INIS)

Hirano, Seishiro; Kobayashi, Yayoi

2006-01-01

Glutathione (GSH) plays an important role in the metabolism of arsenite and arsenate by generating arsenic-glutathione complexes. Although dimethylarsinic acid (DMA V ) is the major metabolite of inorganic arsenicals (iAs) in urine, it is not clear how DMA V is produced from iAs. In the present study we report that S-(dimethylarsino)-glutathione (DMA III (SG)), a putative precursor of dimethylarsinic acid DMA V , was unstable in the culture medium without excess GSH and generated volatile substances which were highly cytotoxic for both rat heart microvascular endothelial cells and HL60, a human leukemia cell line. Cytotoxicity of DMA III (SG) was higher than that of iAs and its LC 5 value was calculated to be 7.8 μM in the endothelial cells. To our surprise DMA III (SG) effectively killed cells in the neighbor wells of the same multi-well dish, indicating that volatile toxic compounds generated from DMA III (SG) in the culture medium. High performance lipid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS) analyses suggested that the freshly generated volatile compounds dissolved into aqueous solution and formed an unstable arsenic compound and the unstable compound was further converted to DMA V . These results suggested that DMA III (SG) exerts its cytotoxicity by generating volatile arsenicals and is implicated in the metabolic conversion of inorganic arsenicals into DMA V , a major final metabolite of inorganic arsenicals in most mammals

Human glutathione transferases catalyzing the bioactivation of anticancer thiopurine prodrugs.

Science.gov (United States)

Eklund, Birgitta I; Gunnarsdottir, Sjofn; Elfarra, Adnan A; Mannervik, Bengt

2007-06-01

cis-6-(2-Acetylvinylthio)purine (cAVTP) and trans-6-(2-acetylvinylthio)guanine (tAVTG) are thiopurine prodrugs provisionally inactivated by an alpha,beta-unsaturated substituent on the sulfur of the parental thiopurines 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG). The active thiopurines are liberated intracellularly by glutathione (GSH) in reactions catalyzed by glutathione transferases (GSTs) (EC 2.5.1.18). Catalytic activities of 13 human GSTs representing seven distinct classes of soluble GSTs have been determined. The bioactivation of cAVTP and tAVTG occurs via a transient addition of GSH to the activated double bond of the S-substituent of the prodrug, followed by elimination of the thiopurine. The first of these consecutive reactions is rate-limiting for thiopurine release, but GST-activation of this first addition is shifting the rate limitation to the subsequent elimination. Highly active GSTs reveal the transient intermediate, which is detectable by UV spectroscopy and HPLC analysis. LC/MS analysis of the reaction products demonstrates that the primary GSH conjugate, 4-glutathionylbuten-2-one, can react with a second GSH molecule to form the 4-(bis-glutathionyl)butan-2-one. GST M1-1 and GST A4-4 were the most efficient enzymes with tAVTG, and GST M1-1 and GST M2-2 had highest activity with cAVTP. The highly efficient GST M1-1 is polymorphic and is absent in approximately half of the human population. GST P1-1, which is overexpressed in many cancer cells, had no detectable activity with cAVTP and only minor activity with tAVTG. Other GST-activated prodrugs have targeted GST P1-1-expressing cancer cells. Tumors expressing high levels of GST M1-1 or GST A4-4 can be predicted to be particularly vulnerable to chemotherapy with cAVTP or tAVTG.

Interactive effects of herbicide and enhanced UV-B on growth, oxidative damage and the ascorbate-glutathione cycle in two Azolla species.

Science.gov (United States)

Prasad, Sheo Mohan; Kumar, Sushil; Parihar, Parul; Singh, Rachana

2016-11-01

A field experiment was conducted to investigate the impact of alone and combined exposures of herbicide pretilachlor (5, 10 and 20μgml(-1)) and enhanced UV-B radiation (UV-B1; ambient +2.2kJm(-2) day(-1) and UV-B2; ambient +4.4kJm(-2) day(-1)) on growth, oxidative stress and the ascorbate-glutathione (AsA-GSH) cycle in two agronomically important Azolla spp. viz., Azolla microphylla and Azolla pinnata. Decreased relative growth rate (RGR) in both the species under tested stress could be linked to enhanced oxidative stress, thus higher H2O2 accumulation was observed, that in turn might have caused severe damage to lipids and proteins, thereby decreasing membrane stability. The effects were exacerbated when spp. were exposed to combined treatments of enhanced UV-B and pretilachlor. Detoxification of H2O2 is regulated by enzymes/metabolites of AsA-GSH cycle such as ascorbate peroxidase (APX) and glutathione reductase (GR) activity that were found to be stimulated. While, dehydroascorabte reductase (DHAR) activity, and the amount of metabolites: ascorbate (AsA), glutathione (GSH) and ratios of reduced/oxidized AsA (AsA/DHA) and GSH (GSH/GSSG), showed significant reduction with increasing doses of both the stressors, either applied alone or in combination. Glutathione-S-transferase (GST), an enzyme involved in scavenging of xenobiotics, was found to be stimulated under the tested stress. This study suggests that decline in DHAR activity and in AsA/DHA ratio might have led to enhanced H2O2 accumulation, thus decreased RGR was noticed under tested stress in both the species and the effect was more pronounced in A. pinnata. Owing to better performance of AsA-GSH cycle in A. microphylla, this study substantiates the view that A. microphylla is more tolerant than A. pinnata. Copyright © 2016 Elsevier Inc. All rights reserved.

Subcellular distribution of glutathione and cysteine in cyanobacteria.

Science.gov (United States)

Zechmann, Bernd; Tomasić, Ana; Horvat, Lucija; Fulgosi, Hrvoje

2010-10-01

Glutathione plays numerous important functions in eukaryotic and prokaryotic cells. Whereas it can be found in virtually all eukaryotic cells, its production in prokaryotes is restricted to cyanobacteria and proteobacteria and a few strains of gram-positive bacteria. In bacteria, it is involved in the protection against reactive oxygen species (ROS), osmotic shock, acidic conditions, toxic chemicals, and heavy metals. Glutathione synthesis in bacteria takes place in two steps out of cysteine, glutamate, and glycine. Cysteine is the limiting factor for glutathione biosynthesis which can be especially crucial for cyanobacteria, which rely on both the sufficient sulfur supply from the growth media and on the protection of glutathione against ROS that are produced during photosynthesis. In this study, we report a method that allows detection and visualization of the subcellular distribution of glutathione in Synechocystis sp. This method is based on immunogold cytochemistry with glutathione and cysteine antisera and computer-supported transmission electron microscopy. Labeling of glutathione and cysteine was restricted to the cytosol and interthylakoidal spaces. Glutathione and cysteine could not be detected in carboxysomes, cyanophycin granules, cell walls, intrathylakoidal spaces, periplasm, and vacuoles. The accuracy of the glutathione and cysteine labeling is supported by two observations. First, preadsorption of the antiglutathione and anticysteine antisera with glutathione and cysteine, respectively, reduced the density of the gold particles to background levels. Second, labeling of glutathione and cysteine was strongly decreased by 98.5% and 100%, respectively, in Synechocystis sp. cells grown on media without sulfur. This study indicates a strong similarity of the subcellular distribution of glutathione and cysteine in cyanobacteria and plastids of plants and provides a deeper insight into glutathione metabolism in bacteria.

Survival curves of irradiated glutathione-deficient human fibroblasts: indication of a reduced enhancement of radiosensitivity by oxygen and misonidazole

International Nuclear Information System (INIS)

Midander, J.; Deschavanne, P.J.; Malaise, E.P.; Revesz, L.

1982-01-01

Fibroblasts derived from a patient with 5-oxoprolinuria are genetically deficient in glutathione synthetase. This deficiency causes a dramatic decrease in intracellular glutathione (GSH) level. The radiosensitivity of GSH deficient cells (GSH) was studied in vitro using colony forming ability as an endpoint. Cells with normal GSH level, obtained from the healthy brother of the patient, were used as controls. When irradiated in 95% air-5% CO 2 , GSH - cells are slightly but significantly more radiosensitive than GSH + controls (dose modifying factor (DMF) of 1.2). When irradiated in argon, the survival curve of GSH - cells indicates an oxygen enhancement ratio (OER) of 1.5 when compared to the curve obtained in oxic conditions. The OER of control cells in the same conditions is 2.9. In comparison to results obtained in air, 100% oxygen moderately increases the radiosensitivity of GSH + cells (DMF 1,23), while it has a very low effect on GSH - cells (DMF 1.06). These results suggest that intracellular GSH plays an essential protective role in hypoxia, its effect is reduced in air and practically disappears in 100% oxygen. When cells are incubated with 8 mM misonidazole 2 hours before irradiation, the drug has a much greater sensitizing effect on GSH + cells (DMF 2.33) than on GSH - cells (DMF 1.55). The results demonstrate that intracellular GSH level plays a major role in the response of hypoxic cells, irradiated either alone or in the presence of misonidazole

Erythrocytic glutathione peroxidase: Its relationship to plasma selenium in man

International Nuclear Information System (INIS)

Perona, G.; Cellerino, R.; Guidi, G.C.; Moschini, G.; Stievano, B.M.; Tregnaghi, C.

1977-01-01

Erythrocytic glutathione-peroxidase (GSH-Px) activity and plasma selenium concentrations were measured in 14 patients: 7 with iron deficiency and 7 with raised serum iron levels. The decreased enzymatic activity in iron deficiency was confirmed. Plasma selenium was significantly lower in patients with lower serum iron; furthermore there is a significant correlation between serum iron and plasma selenium concentrations. Another correlation even more significant was found between plasma selenium and enzyme activity in all the cases we studied. These data suggests that the importance of iron for GSH-Px activity may be merely due to its relationship with selenium and that plasma selenium concentration may be of critical importance for enzyme activity. (author)

A regulatory review for products containing glutathione

Directory of Open Access Journals (Sweden)

Nur Hidayah Abd Rahim

2016-01-01

Full Text Available Glutathione is a potent antioxidant as well as has important role for DNA synthesis and repair, protein synthesis, amino acid transport, and enzyme activation. Besides this, Glutathione products are now mainly selling as whitening agent which are mainly marketing through social media (Facebook and different websites. Information is not available whether glutathione product are following the regulatory guidelines of National Pharmaceutical Control Bureau of Malaysia (NPCB for selling, advertisement and promotion. This review was carried out by extracting information about glutathione from scientific database using PubMed, Cochrane Library and Embase. Analysis of the available information, case example of glutathione products showed that a brand of glutathione (Glutacaps HQ did not show the product's registration number from NPCB, and also did not show the name, address, contact number of the advertiser, and even not found the name of the manufacture. Without providing the above mentioned information, the product is selling and promoting through social media (fb which is not allowed by the NPCB guidelines part 4.14. So far, only two clinical trials were conducted on glutathione supplementation for 4 weeks duration. There was no serious or systematic adverse effects reported in clinical trials. As the two clinic trials resulted contradictory outcomes, further studies needed for conformation of the clinic benefits of glutathione. Otherwise, random use of glutathione may be risk for the health of the people. Besides, the marketer mainly promoting glutathione as the skin whitening beauty product instead of using as health supplement, it may cause additional and serious risk to the users as the manufacturer not providing sufficient information about the product, its registration number, manufacturing company, etc.

Role of protein-glutathione contacts in defining glutaredoxin-3 [2Fe-2S] cluster chirality, ligand exchange and transfer chemistry.

Science.gov (United States)

Sen, Sambuddha; Cowan, J A

2017-10-01

Monothiol glutaredoxins (Grx) serve as intermediate cluster carriers in iron-sulfur cluster trafficking. The [2Fe-2S]-bound holo forms of Grx proteins display cysteinyl coordination from exogenous glutathione (GSH), in addition to contact from protein-derived Cys. Herein, we report mechanistic studies that investigate the role of exogenous glutathione in defining cluster chirality, ligand exchange, and the cluster transfer chemistry of Saccharomyces cerevisiae Grx3. Systematic perturbations were introduced to the glutathione-binding site by substitution of conserved charged amino acids that form crucial electrostatic contacts with the glutathione molecule. Native Grx3 could also be reconstituted in the absence of glutathione, with either DTT, BME or free L-cysteine as the source of the exogenous Fe-S ligand contact, while retaining full functional reactivity. The delivery of the [2Fe-2S] cluster to Grx3 from cluster donor proteins such as Isa, Nfu, and a [2Fe-2S](GS) 4 complex, revealed that electrostatic contacts are of key importance for positioning the exogenous glutathione that in turn influences the chiral environment of the cluster. All Grx3 derivatives were reconstituted by standard chemical reconstitution protocols and found to transfer cluster to apo ferredoxin 1 (Fdx1) at rates comparable to native protein, even when using DTT, BME or free L-cysteine as a thiol source in place of GSH during reconstitution. Kinetic analysis of cluster transfer from holo derivatives to apo Fdx1 has led to a mechanistic model for cluster transfer chemistry of native holo Grx3, and identification of the likely rate-limiting step for the reaction.

Signaling molecule methylglyoxal ameliorates cadmium injury in wheat (Triticum aestivum L) by a coordinated induction of glutathione pool and glyoxalase system.

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Li, Zhong-Guang; Nie, Qian; Yang, Cong-Li; Wang, Yue; Zhou, Zhi-Hao

2018-03-01

Methylglyoxal (MG) now is found to be an emerging signaling molecule. It can relieve the toxicity of cadmium (Cd), however its alleviating mechanism still remains unknown. In this study, compared with the Cd-stressed seedlings without MG treatment, MG treatment could stimulate the activities of glutathione reductase (GR) and gamma-glutamylcysteine synthetase (γ-ECS) in Cd-stressed wheat seedlings, which in turn induced an increase of reduced glutathione (GSH). Adversely, the activated enzymes related to GSH biosynthesis and increased GSH were weakened by N-acetyl-L-cysteine (NAC, MG scavenger), 2,4-dihydroxy-benzylamine (DHBA) and 1,3-bischloroethyl-nitrosourea (BCNU, both are specific inhibitors of GR), buthionine sulfoximine (BSO, a specific inhibitors of GSH biosynthesis), and N-ethylmaleimide (NEM, GSH scavenger), respectively. In addition, MG increased the activities of glyoxalase I (Gly I) and glyoxalase II (Gly II) in Cd-treated seedlings, followed by declining an increase in endogenous MG as comparision to Cd-stressed seedlings alone. On the contrary, the increased glyoxalase activity and decreased endogenous MG level were reversed by NAC and specific inhibitors of Gly I (isoascorbate, IAS; squaric acid, SA). Furthermore, MG alleviated an increase in hydrogen peroxide (H 2 O 2 ) and malondialdehyde (MDA) in Cd-treated wheat seedlings. These results indicated that MG could alleviate Cd toxicity and improve the growth of Cd-stressed wheat seedlings by a coordinated induction of glutathione pool and glyoxalase system. Copyright © 2017 Elsevier Inc. All rights reserved.

Synthesis and structural elucidation of glutathione and N-aceyl-cysteine conjugates of 5-aminosalicylic acid

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Jensen, J.; Cornett, Claus; Olsen, C. E.

1993-01-01

The ability of 5-aminosalicylic acid (5-ASA) to be oxidized to a quinone monoimine compound capable of conjugating with nucleophilic compounds such as N-acetyl-cysteine (NAC) and glutathione (GSH) has been investigated in vitro. Three isomeric conjugates of 5-ASA and NAC as well as three isomeric...... conjugates of 5-ASA and GSH were found to be formed. 5-ASA was initially oxidized by PbO2 in a solution of TRIS-HCl buffer pH 9.3 followed by the in situ addition of N-acetyl-cysteine or glutathione to the oxidized 5-ASA at pH 7.5. The resulting conjugates were N-acetylated at the aromatic amino group...... to investigate whether such conjugates are excreted in the urine from persons treated with 5-ASA. The N-acetyl-cysteine conjugates could be detected by fluorescense, which resulted in low detection limits ranging from 0.02 mug to 0.06 mug per ml corresponding to the transformation of about 0.003% of the daily...

Timing of developmental reduction in epithelial glutathione redox potential is associated with increased epithelial proliferation in the immature murine intestine.

Science.gov (United States)

Reid, Graham K; Berardinelli, Andrew J; Ray, Laurie; Jackson, Arena R; Neish, Andrew S; Hansen, Jason M; Denning, Patricia W

2017-08-01

BackgroundThe intracellular redox potential of the glutathione (GSH)/glutathione disulfide (GSSG) couple regulates cellular processes. In vitro studies indicate that a reduced GSH/GSSG redox potential favors proliferation, whereas a more oxidized redox potential favors differentiation. Intestinal growth depends upon an appropriate balance between the two. However, how the ontogeny of intestinal epithelial cellular (IEC) GSH/GSSG redox regulates these processes in the developing intestine has not been fully characterized in vivo.MethodsOntogeny of intestinal GSH redox potential and growth were measured in neonatal mice.ResultsWe show that IEC GSH/GSSG redox potential becomes increasingly reduced (primarily driven by increased GSH concentration) over the first 3 weeks of life. Increased intracellular GSH has been shown to drive proliferation through increased poly-ADP-ribose polymerase (PARP) activity. We show that increasing IEC poly-ADP-ribose chains can be measured over the first 3 weeks of life, indicating an increase in IEC PARP activity. These changes are accompanied by increased intestinal growth and IEC proliferation as assessed by villus height/crypt depth, intestinal length, and Ki67 staining.ConclusionUnderstanding how IEC GSH/GSSG redox potential is developmentally regulated may provide insight into how premature human intestinal redox states can be manipulated to optimize intestinal growth and adaptation.

Role of glutathione transport processes in kidney function

International Nuclear Information System (INIS)

Lash, Lawrence H.

2005-01-01

The kidneys are highly dependent on an adequate supply of glutathione (GSH) to maintain normal function. This is due, in part, to high rates of aerobic metabolism, particularly in the proximal tubules. Additionally, the kidneys are potentially exposed to high concentrations of oxidants and reactive electrophiles. Renal cellular concentrations of GSH are maintained by both intracellular synthesis and transport from outside the cell. Although function of specific carriers has not been definitively demonstrated, it is likely that multiple carriers are responsible for plasma membrane transport of GSH. Data suggest that the organic anion transporters OAT1 and OAT3 and the sodium-dicarboxylate 2 exchanger (SDCT2 or NaDC3) mediate uptake across the basolateral plasma membrane (BLM) and that the organic anion transporting polypeptide OATP1 and at least one of the multidrug resistance proteins mediate efflux across the brush-border plasma membrane (BBM). BLM transport may be used pharmacologically to provide renal proximal tubular cells with exogenous GSH to protect against oxidative stress whereas BBM transport functions physiologically in turnover of cellular GSH. The mitochondrial GSH pool is derived from cytoplasmic GSH by transport into the mitochondrial matrix and is mediated by the dicarboxylate and 2-oxoglutarate exchangers. Maintenance of the mitochondrial GSH pool is critical for cellular and mitochondrial redox homeostasis and is important in determining susceptibility to chemically induced apoptosis. Hence, membrane transport processes are critical to regulation of renal cellular and subcellular GSH pools and are determinants of susceptibility to cytotoxicity induced by oxidants and electrophiles

Altered glycogen metabolism in cultured astrocytes from mice with chronic glutathione deficit; relevance for neuroenergetics in schizophrenia.

OpenAIRE

Lavoie, S.; Allaman, I.; Petit, J.M.; Do, K.Q.; Magistretti, P.J.

2011-01-01

Neurodegenerative and psychiatric disorders including Alzheimer's, Parkinson's or Huntington's diseases and schizophrenia have been associated with a deficit in glutathione (GSH). In particular, a polymorphism in the gene of glutamate cysteine ligase modulatory subunit (GCLM) is associated with schizophrenia. GSH is the most important intracellular antioxidant and is necessary for the removal of reactive by-products generated by the utilization of glucose for energy supply. Furthermore, gluco...

Influence of reduced glutathione on end-joining of DNA double-strand breaks: Cytogenetical and molecular approach

Energy Technology Data Exchange (ETDEWEB)

Ghoshal, Nitin [Molecular Genetics Laboratory, Department of Biotechnology & Bioinformatics, North-Eastern Hill University, Shillong, Meghalaya-793022 (India); Sharma, Sheetal [Department of Biochemistry, Indian Institute of Science, Bangalore, 560 012 (India); Banerjee, Atanu; Kurkalang, Sillarine [Molecular Genetics Laboratory, Department of Biotechnology & Bioinformatics, North-Eastern Hill University, Shillong, Meghalaya-793022 (India); Raghavan, Sathees C. [Department of Biochemistry, Indian Institute of Science, Bangalore, 560 012 (India); Chatterjee, Anupam, E-mail: chatterjeeanupam@hotmail.com [Molecular Genetics Laboratory, Department of Biotechnology & Bioinformatics, North-Eastern Hill University, Shillong, Meghalaya-793022 (India)

2017-01-15

Highlights: • DNA lesions induced by Blem and radiation interact well and form higher frequency of exchange aberrations. • Cellular level of glutathione does influence such interaction of DNA lesions. • Oligomer-based cell-free assay system demonstrated better end-joining efficiency at higher level of endogenous GSH. - Abstract: Radiation induced DNA double-strand breaks (DSB) are the major initial lesions whose misrejoining may lead to exchange aberrations. However, the role of glutathione (GSH), a major cellular thiol, in regulating cell’s sensitivity to DNA damaging agents is not well understood. Influence of endogenous GSH on the efficiency of X-rays and bleomycin (Blem) induced DNA DSBs end-joining has been tested here cytogenetically, in human lymphocytes and Hct116 cells. In another approach, oligomeric DNA (75 bp) containing 5′-compatible and non-compatible overhangs mimicking the endogenous DSB were for rejoining in presence of cell-free extracts from cells having different endogenous GSH levels. Frequency of aberrations, particularly exchange aberrations, was significantly increased when Blem was combined with radiation. The exchange aberration frequency was further enhanced when combined treatment was given at 4 °C since DNA lesions are poorly repaired at 4 °C so that a higher number of DNA breaks persist and interact when shifted from 4 °C to 37 °C. The exchange aberrations increased further when the combined treatment was given to Glutathione-ester (GE) pre-treated cells, indicating more frequent rejoining of DNA lesions in presence of higher cellular GSH. This is further supported by the drastic reduction in frequency of exchange aberrations but significant increase in incidences of deletions when combined treatment was given to GSH-depleted cells. End-joining efficiency of DNA DSBs with compatible ends was better than for non-compatible ends. End-joining efficiency of testicular and MCF7 cell extracts was better than that of lungs and

Degree of glutathione deficiency and redox imbalance depend on subtype of mitochondrial disease and clinical status.

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Gregory M Enns

Full Text Available Mitochondrial disorders are associated with decreased energy production and redox imbalance. Glutathione plays a central role in redox signaling and protecting cells from oxidative damage. In order to understand the consequences of mitochondrial dysfunction on in vivo redox status, and to determine how this varies by mitochondrial disease subtype and clinical severity, we used a sensitive tandem mass spectrometry assay to precisely quantify whole blood reduced (GSH and oxidized (GSSG glutathione levels in a large cohort of mitochondrial disorder patients. Glutathione redox potential was calculated using the Nernst equation. Compared to healthy controls (n = 59, mitochondrial disease patients (n = 58 as a group showed significant redox imbalance (redox potential -251 mV ± 9.7, p<0.0001 with an increased level of oxidation by ∼ 9 mV compared to controls (-260 mV ± 6.4. Underlying this abnormality were significantly lower whole blood GSH levels (p = 0.0008 and GSH/GSSG ratio (p = 0.0002, and significantly higher GSSG levels (p<0.0001 in mitochondrial disease patients compared to controls. Redox potential was significantly more oxidized in all mitochondrial disease subgroups including Leigh syndrome (n = 15, electron transport chain abnormalities (n = 10, mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (n = 8, mtDNA deletion syndrome (n = 7, mtDNA depletion syndrome (n = 7, and miscellaneous other mitochondrial disorders (n = 11. Patients hospitalized in metabolic crisis (n = 7 showed the greatest degree of redox imbalance at -242 mV ± 7. Peripheral whole blood GSH and GSSG levels are promising biomarkers of mitochondrial dysfunction, and may give insights into the contribution of oxidative stress to the pathophysiology of the various mitochondrial disorders. In particular, evaluation of redox potential may be useful in monitoring of clinical status or response to redox-modulating therapies in clinical trials.

Analysis of glutathione in supernatants and lysates of a human proximal tubular cell line from perfusion culture upon intoxication with cadmium chloride by HPLC and LC-ESI-MS

NARCIS (Netherlands)

Hahn, Hans; Huck, Christian W; Rainer, Matthias; Najam-ul-Haq, Muhammad; Bakry, Rania; Abberger, Thomas; Jennings, Paul; Pfaller, Walter; Bonn, Günther K

A simple and highly effective reversed-phase (RP) high-performance liquid chromatography (HPLC) method is described for analysing glutathione (GSH) and glutathione disulfide (GSSG) in out-flowing supernatants and lysates of perfusion cell cultures of human kidney cells (HK-2 cells) continuously

Organophosphorus insecticides chlorpyrifos and diazinon and oxidative stress in neuronal cells in a genetic model of glutathione deficiency

International Nuclear Information System (INIS)

Giordano, Gennaro; Afsharinejad, Zhara; Guizzetti, Marina; Vitalone, Annabella; Kavanagh, Terrance J.; Costa, Lucio G.

2007-01-01

Over the past several years evidence has been accumulating from in vivo animal studies, observations in humans, and in vitro studies, that organophosphorus (OP) insecticides may induce oxidative stress. Such effects may contribute to some of the toxic manifestations of OPs, particularly upon chronic or developmental exposures. The aim of this study was to investigate the role of oxidative stress in the neurotoxicity of two commonly used OPs, chlorpyrifos (CPF) and diazinon (DZ), their oxygen analogs (CPO and DZO), and their 'inactive' metabolites (TCP and IMP), in neuronal cells from a genetic model of glutathione deficiency. Cerebellar granule neurons from wild type mice (Gclm +/+) and mice lacking the modifier subunit of glutamate cysteine ligase (Gclm -/-), the first and limiting step in the synthesis of glutathione (GSH), were utilized. The latter display very low levels of GSH and are more susceptible to the toxicity of agents that increase oxidative stress. CPO and DZO were the most cytotoxic compounds, followed by CPF and DZ, while TCP and IMP displayed lower toxicity. Toxicity was significantly higher (10- to 25-fold) in neurons from Gclm (-/-) mice, and was antagonized by various antioxidants. Depletion of GSH from Gclm (+/+) neurons significantly increased their sensitivity to OP toxicity. OPs increased intracellular levels of reactive oxygen species and lipid peroxidation and in both cases the effects were greater in neurons from Gclm (-/-) mice. OPs did not alter intracellular levels of GSH, but significantly increased those of oxidized glutathione (GSSG). Cytotoxicity was not antagonized by cholinergic antagonists, but was decreased by the calcium chelator BAPTA-AM. These studies indicate that cytotoxicity of OPs involves generation of reactive oxygen species and is modulated by intracellular GSH, and suggest that it may involve disturbances in intracellular homeostasis of calcium

Identification of quinone imine containing glutathione conjugates of diclofenac in rat bile.

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Waldon, Daniel J; Teffera, Yohannes; Colletti, Adria E; Liu, Jingzhou; Zurcher, Danielle; Copeland, Katrina W; Zhao, Zhiyang

2010-12-20

High-resolution accurate MS with an LTQ-Orbitrap was used to identify quinone imine metabolites derived from the 5-hydroxy (5-OH) and 4 prime-hydroxy (4'-OH) glutathione conjugates of diclofenac in rat bile. The initial quinone imine metabolites formed by oxidation of diclofenac have been postulated to be reactive intermediates potentially involved in diclofenac-mediated hepatotoxicity; while these metabolites could be formed using in vitro systems, they have never been detected in vivo. This report describes the identification of secondary quinone imine metabolites derived from 5-OH and 4'-OH diclofenac glutathione conjugates in rat bile. To verify the proposed structures, the diclofenac quinone imine GSH conjugate standards were prepared synthetically and enzymatically. The novel metabolite peaks displayed the identical retention times, accurate mass MS/MS spectra, and the fragmentation patterns as the corresponding authentic standards. The formation of these secondary quinone metabolites occurs only under conditions where bile salt homeostasis was experimentally altered. Standard practice in biliary excretion experiments using bile duct-cannulated rats includes infusion of taurocholic acid and/or other bile acids to replace those lost due to continuous collection of bile; for this experiment, the rats received no replacement bile acid infusion. High-resolution accurate mass spectrometry data and comparison with chemically and enzymatically prepared quinone imines of diclofenac glutathione conjugates support the identification of these metabolites. A mechanism for the formation of these reactive quinone imine containing glutathione conjugates of diclofenac is proposed.

Experimental type 2 diabetes mellitus and acetaminophen toxic lesions: glutathione system indices changes

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Olga Furka

2017-11-01

Full Text Available Background. The goal of the research was to study the effect of acetaminophen on major glutathione part of antioxidant system indices in liver homogenate of rats with type 2 diabetes mellitus in time dynamics. Materials and methods. We conducted two series of experiments. In the first series toxic lesion was caused by a single intragastric administration of acetaminophen suspension in 2 % starch solution to animals in a dose of 1250 mg/kg (1/2 LD50. In the second series  the suspension of acetaminophen in 2 % starch solution in a dose of 55 mg/kg was given, which corresponds to the highest therapeutic dose during 7 days. Non-genetic form of experimental type 2 diabetes mellitus was modeled by Islam S., Choi H. method (2007. Activity of glutathione peroxidase (GPx and glutathione reductase (GR, and contents of reduced glutathione (GSH were determined in liver homogenate. Results. The obtained results have shown that GR and GPx activity actively decreased after acetaminophen administration in higher therapeutic doses to rats with type 2 DM. However, the changes were less pronounced than in rats with type 2 DM and acute acetaminophen toxic lesions. Conclusion. Results of the research have shown that acetaminophen administration to rats with type 2 DM causes a significant violation of compensatory mechanisms, especially of the enzyme and nonenzyme parts of antioxidant system.

Electrochemical determination of glutathione in plasma at carbon nanotubes based screen printed electrodes.

Science.gov (United States)

Turunc, Ezgi; Karadeniz, Hakan; Armagan, Guliz; Erdem, Arzum; Yalcin, Ayfer

2013-11-01

Glutathione (GSH) is a major endogenous antioxidant highly active in human tissues and plays a key role in controlling cellular thiol redox system, maintaining the immune and detoxification system. The determination of GSH levels in tissue is important to estimate endogenous defenses against oxidative stress. In our study, the multi-walled carbon nanotube modified screen-printed electrodes (MWCNT-SPEs) were used to determine the levels of GSH in trichloroacetic acid (TCA)-treated or untreated samples of rat plasma. It was found that the deproteinization of samples with TCA improved the electrochemical detection of GSH particularly in plasma. The oxidation of GSH was measured by using differential pulse voltammetry (DPV) method in combination with MWCNT-SPE (n=3), and the detection limit of GSH was found to be 0.47 µM (S/N=3). The GSH levels in plasma samples were also measured spectrophotometrically in order to compare the effectiveness of electrochemical method and we obtained a high correlation between the two methods (R(2)=0.976).

Depletion of liver glutathione levels in rats: a potential confound of nose-only inhalation.

Science.gov (United States)

Fechter, Laurence D; Nelson-Miller, Alisa; Gearhart, Caroline

2008-07-01

Nose-only inhalation exposure chambers offer key advantages to whole-body systems, particularly when aerosol or mixed aerosol-vapor exposures are used. Specifically, nose-only chambers provide enhanced control over the route of exposure and dose by minimizing the deposition of particles either on the subjects skin/fur or on surfaces of a whole-body exposure system. In the current series of experiments, liver, brain, and lung total glutathione (GSH) levels were assessed following either nose-only or whole-body exposures to either jet fuel or to clean, filtered air. The data were compared to untreated control subjects. Acute nose-only inhalation exposures of rats resulted in a significant depletion of liver GSH levels both in subjects that were exposed to clean, filtered air as well as those exposed to JP-8 jet fuel and to a synthetic jet fuel. Glutathione levels were not altered in lung or brain tissue. Whole-body inhalation exposure had no effect on GSH levels in any tissue for any of the treatment groups. A second experiment demonstrated that the loss of GSH did not occur if rats were anaesthetized prior to and during nose-only exposure to clean, filtered air or to mixed hydrocarbons. These data appear to be consistent with studies demonstrating depletion in liver GSH levels among rats subjected to restraint stress. Finally, the depletion of GSH that was observed in liver following a single acute exposure was reduced following five daily exposures to clean, filtered air, suggesting the possibility of habituation to restraint in the nose-only exposure chamber. The finding that placement in a nose-only exposure chamber per se yields liver GSH depletion raises the possibility of an interaction between this mode of toxicant exposure and the toxicological effects of certain inhaled test substances.

Antioxidant role of glutathione S-transferases: 4-Hydroxynonenal, a key molecule in stress-mediated signaling

International Nuclear Information System (INIS)

Singhal, Sharad S.; Singh, Sharda P.; Singhal, Preeti; Horne, David; Singhal, Jyotsana; Awasthi, Sanjay

2015-01-01

4-Hydroxy-2-trans-nonenal (4HNE), one of the major end products of lipid peroxidation (LPO), has been shown to induce apoptosis in a variety of cell lines. It appears to modulate signaling processes in more than one way because it has been suggested to have a role in signaling for differentiation and proliferation. It has been known that glutathione S-transferases (GSTs) can reduce lipid hydroperoxides through their Se-independent glutathione-peroxidase activity and that these enzymes can also detoxify LPO end-products such as 4HNE. Available evidence from earlier studies together with results of recent studies in our laboratories strongly suggests that LPO products, particularly hydroperoxides and 4HNE, are involved in the mechanisms of stress-mediated signaling and that it can be modulated by the alpha-class GSTs through the regulation of the intracellular concentrations of 4HNE. We demonstrate that 4HNE induced apoptosis in various cell lines is accompanied with c-Jun-N-terminal kinase (JNK) and caspase-3 activation. Cells exposed to mild, transient heat or oxidative stress acquire the capacity to exclude intracellular 4HNE at a faster rate by inducing GSTA4-4 which conjugates 4HNE to glutathione (GSH), and RLIP76 which mediates the ATP-dependent transport of the GSH-conjugate of 4HNE (GS-HNE). The balance between formation and exclusion promotes different cellular processes — higher concentrations of 4HNE promote apoptosis; whereas, lower concentrations promote proliferation. In this article, we provide a brief summary of the cellular effects of 4HNE, followed by a review of its GST-catalyzed detoxification, with an emphasis on the structural attributes that play an important role in the interactions with alpha-class GSTA4-4. Taken together, 4HNE is a key signaling molecule and that GSTs being determinants of its intracellular concentrations, can regulate stress-mediated signaling, are reviewed in this article. - Highlights: • GSTs are the major

Role of cellular antioxidants (glutathione and ascorbic acid) in the growth and development of wild carrot suspension cultures

International Nuclear Information System (INIS)

Earnshaw, B.A.

1986-01-01

Determinations of endogenous glutathione (GSH), glutathione disulfide (GSSG), ascorbic acid (AA) and dehydroascorbic acid (DHA) in proliferating and developing wild carrot cultures showed that lower levels of GSH and AA were associated with developing cultures. The GSSG and DHA levels did not account for the changes in the levels of antioxidants between proliferating and developing cultures. Studies were designed to test an observed auxin (2,4-Dichlorophenoxyacetic acid, 2,4-D)-antioxidant association. Two fractions (embryo and less developed) were obtained by screening developed cultures which were previously grown in the presence of 14 C-2, 4-D. The embryo fraction had a lower concentration of 14 C than the less developed fraction, supporting the association, since the two fractions showed this relationship with respect to GSH and AA concentrations. Determinations of GSH and AA levels of cells grown in various concentrations of 2,4-D showed the association, decreases in the 2,4-D concentration correlated with decreases in the GSH and AA concentrations. The existence of a respiratory pathway involving GSSG reductase, DHA reductase, and AA oxidase was investigated to test whether inhibition of AA oxidase by 2,4-D could explain the auxin-antioxidant association; however, AA oxidase activity was not detected

Effect of cellular glutathione content on the induction of DNA double strand breaks by 25 MeV electrons

Energy Technology Data Exchange (ETDEWEB)

Frankenberg, D.; Kistler, M.; Eckhardt-Schupp, F.

1987-08-01

The effect of endogenous glutathione (GSH) on the induction of DNA double strand breaks (dsb) by 25 MeV electrons was investigated using stationary haploid yeast cells defective in ..gamma..-glutamyl-cysteine-synthetase (gsh 1) containing less than 5 per cent of the normal GSH content. In gsh 1 cells the induction of dsb is increased by a factor of 1.5 under oxic and 1.8 under anoxic irradiation conditions whereas the oxygen enhancement ratio was only slightly decreased (1.9) compared to wild-type cells (2.4).

Effect of cellular glutathione content on the induction of DNA double strand breaks by 25 MeV electrons

International Nuclear Information System (INIS)

Frankenberg, D.; Kistler, M.; Eckhardt-Schupp, F.

1987-01-01

The effect of endogenous glutathione (GSH) on the induction of DNA double strand breaks (dsb) by 25 MeV electrons was investigated using stationary haploid yeast cells defective in γ-glutamyl-cysteine-synthetase (gsh 1) containing less than 5 per cent of the normal GSH content. In gsh 1 cells the induction of dsb is increased by a factor of 1.5 under oxic and 1.8 under anoxic irradiation conditions whereas the oxygen enhancement ratio was only slightly decreased (1.9) compared to wild-type cells (2.4). (author)

Effect of exogenous glutathione in medium fertilization to improve blastocyst rates of bovine embryos

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E Triwulaninngsih

2002-06-01

Full Text Available Glutathione (C10H17N3O6S is a tripeptide (γ-Glu-Cys-Gly widespread in living organism. Glutathione (GSH at the 5 mM concentration increased the motility and fertility of frozen-thawed sperm. Intracellulair glutathione improved the cleavage rate and embryo development to the blastocyst rate. Research on in vitro embryos production through the implementation of GSH during IVF (in vitro fertilization on embryo development has been conducted at the Laboratorium Reproductive of Physiology, Research Institute for Animal Production. Ovaries of beef cattle as source of oocytes were collected from the slaughterhouse in a thermo flask with 350C PBS as medium and transported to the laboratory. The oocytes were fertilized in vitro with selected motile sperm using Percoll gradient (90 and 45%. Ten COCs (cumulus oocytes complexes were transfered to 44 μl of fertilization medium (mTALP was performed with either 0; 0.25; 0.50; 0.75 and 1.00 mM of glutathione as treatment A, B, C, D and E respectively, and inseminated with 2 μl of capacitated sperm and added 2 μl of heparin and 2 μl of PHE (consisting of 20 μM penicillamine, 10 μM hypotaurine, 1 μM epinephrine. Incubation between sperm and oocytes in the 5% CO2 incubator and RH 90% in fertilization media (TALP for 20 hours. All zygotes were cultured in modification of CR1aa medium up to blastocyst and were fed serum 5 μl/50μl medium on day 6. Results of this experiment showed that the effect of concentration of glutathione (0, 0.25; 0.50; 0.75 and 1.00 mM on fertilization medium to the percentage of cleavage rates were 69.35 + 29.40; 79.07 + 13.17; 67.88 + 10.65; 98.10 + 3.30 and 82.62 + 24.19% not significant different (P>0.05 among treatments A, B, C, D dan E respectively.The precentages of morula and blastocyst for treatment D were 50.45 + 42.64% and 31.28 + 24.28%; while 36.55 + 24.13% and 17.74 + 17.86% for treatment E respectively.

The poplar phi class glutathione transferase: expression, activity and structure of GSTF1

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Henri ePégeot

2014-12-01

Full Text Available Glutathione transferases (GSTs constitute a superfamily of enzymes with essential roles in cellular detoxification and secondary metabolism in plants as in other organisms. Several plant GSTs, including those of the Phi class (GSTFs, require a conserved catalytic serine residue to perform glutathione (GSH-conjugation reactions. Genomic analyses revealed that terrestrial plants have around 10 GSTFs, 8 in the Populus trichocarpa genome, but their physiological functions and substrates are mostly unknown. Transcript expression analyses showed a predominant expression of all genes both in reproductive (female flowers, fruits, floral buds and vegetative organs (leaves, petioles. Here, we show that the recombinant poplar GSTF1 (PttGSTF1 possesses peroxidase activity towards cumene hydroperoxide and GSH-conjugation activity towards model substrates such as 2,4-dinitrochlorobenzene, benzyl and phenetyl isothiocyanate, 4-nitrophenyl butyrate and 4-hydroxy-2-nonenal but interestingly not on previously identified GSTF-class substrates. In accordance to analytical gel filtration data, crystal structure of PttGSTF1 showed a canonical dimeric organization with bound GSH or MES molecules. The structure of these protein-substrate complexes allowed delineating the residues contributing to both the G and H sites that form the active site cavity. In sum, the presence of GSTF1 transcripts and proteins in most poplar organs especially those rich in secondary metabolites such as flowers and fruits, together with its GSH-conjugation activity and its documented stress-responsive expression suggest that its function is associated with the catalytic transformation of metabolites and/or peroxide removal rather than with ligandin properties as previously reported for other GSTFs.

Both the concentration and redox state of glutathione and ascorbate influence the sensitivity of arabidopsis to cadmium

NARCIS (Netherlands)

Jozefczak, M.; Bohler, S.; Schat, H.; Horemans, N.; Guisez, Y.; Remans, T.; Vangronsveld, J.; Cuypers, A.

2015-01-01

Background and Aims Cadmium (Cd) is a non-essential trace element that elicits oxidative stress. Plants respond to Cd toxicity via increasing their Cd-chelating and antioxidative capacities. They predominantly chelate Cd via glutathione (GSH) and phytochelatins (PCs), while antioxidative defence is

CHARACTERIZATION OF DANSYLATED CYSTEINE, GLUTATHIONE DISULFIDE, CYSTEINE AND CYSTINE BY NARROW BORE LIQUID CHROMATOGRAPHY/ELECTROSPRAY IONIZATION MASS SPECTROMETRY

Science.gov (United States)

A method using reversed phase high performance liquid chromatography/electrospray ionization-mass spectrometric (RP-LC/ESI-MS) method has been developed to confirm the identity of dansylated derivatives of cysteine and glutathione, and their respective dimers. Cysteine, GSH, CSSC...

Study the interaction between CdTe-glutathione and human serum albumin

International Nuclear Information System (INIS)

Yang, Qing; Zhou, Xi-min; Zhu, Yi-shuo; Chen, Xing-guo

2013-01-01

In this paper, glutathione (GSH) modified CdTe quantum dots (CdTe-GSH QDs) were synthesized in an aqueous solution. Then, the binding of the CdTe-GSH QDs to human serum albumin (HSA) was studied using the fluorescence spectroscopy. The quenching mechanism was investigated in terms of the association constants and basic thermodynamic parameters. The fluorescence data revealed that CdTe-GSH QDs could quench the intrinsic fluorescence of human serum albumin by a static quenching mechanism. Furthermore, alteration of the secondary protein structure in the presence of the QDs was confirmed by synchronous fluorescence spectra. - Highlights: ► In this paper, the binding of the CdTe-GSH QDs to human serum albumin (HSA) was studied using a fluorescence spectroscopy. ► The quenching mechanism was investigated in terms of the association constants and basic thermodynamic parameters. ► Furthermore, alteration of the secondary protein structure in the presence of the QDs was confirmed by synchronous fluorescence spectra. ► The research can help us assess biological toxicity of QDs and further expand the application scope of QDs.

Phytoextraction of toxic metals: a central role for glutathione.

Science.gov (United States)

Seth, C S; Remans, T; Keunen, E; Jozefczak, M; Gielen, H; Opdenakker, K; Weyens, N; Vangronsveld, J; Cuypers, A

2012-02-01

Phytoextraction has a promising potential as an environmentally friendly clean-up method for soils contaminated with toxic metals. To improve the development of efficient phytoextraction strategies, better knowledge regarding metal uptake, translocation and detoxification in planta is a prerequisite. This review highlights our current understanding on these mechanisms, and their impact on plant growth and health. Special attention is paid to the central role of glutathione (GSH) in this process. Because of the high affinity of metals to thiols and as a precursor for phytochelatins (PCs), GSH is an essential metal chelator. Being an important antioxidant, a direct link between metal detoxification and the oxidative challenge in plants growing on contaminated soils is observed, where GSH could be a key player. In addition, as redox couple, oxidized and reduced GSH transmits specific information, in this way tuning cellular signalling pathways under environmental stress conditions. Possible improvements of phytoextraction could be achieved by using transgenic plants or plant-associated microorganisms. Joined efforts should be made to cope with the challenges faced with phytoextraction in order to successfully implement this technique in the field. © 2011 Blackwell Publishing Ltd.

Optimization of Reduced Glutathione Production by a Lactobacillus plantarum Isolate Using Plackett-Burman and Box-Behnken Designs.

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Al-Madboly, Lamiaa A; Khedr, Eman G; Ali, Safaa M

2017-01-01

In this work, we aim to optimize the production of reduced glutathione (GSH) synthesized intracellularly by a food-grade microorganism through a statistical approach. Using a colorimetric method, 25 Lactobacillus plantarum isolates were screened in an attempt to find a GSH-producing strain. It was found that 36% of the tested isolates showed positive result. Isolate (L 7 ) was found to produce 152.61 μM glutathione per gram which was the highest amount produced intracellularly. Accordingly, the later isolate was selected for the optimization process using Plackett-Burman and Box-Behnken designs. Temperature, amino acids, and urea were found to be the most significant independent variables. Following data analysis, the composition of the optimized medium was De Man-Sharp-Rogosa broth as a basal medium supplemented with NaCl (5%), H 2 O 2 (0.05%), sodium dodecyl sulfate (0.05%), amino acids (0.0281%), and urea (0.192%). The pH of the medium was adjusted to 8 and incubated for 24 h at 40°C. The GSH amount was increased by 10-fold (851%) using the optimized medium. Hence, our optimization design estimated the biotechnological potential of L. plantarum (L 7 ) for the production of GSH in the industry.

Optimization of Reduced Glutathione Production by a Lactobacillus plantarum Isolate Using Plackett–Burman and Box–Behnken Designs

Science.gov (United States)

Al-Madboly, Lamiaa A.; Khedr, Eman G.; Ali, Safaa M.

2017-01-01

In this work, we aim to optimize the production of reduced glutathione (GSH) synthesized intracellularly by a food-grade microorganism through a statistical approach. Using a colorimetric method, 25 Lactobacillus plantarum isolates were screened in an attempt to find a GSH-producing strain. It was found that 36% of the tested isolates showed positive result. Isolate (L7) was found to produce 152.61 μM glutathione per gram which was the highest amount produced intracellularly. Accordingly, the later isolate was selected for the optimization process using Plackett–Burman and Box–Behnken designs. Temperature, amino acids, and urea were found to be the most significant independent variables. Following data analysis, the composition of the optimized medium was De Man-Sharp-Rogosa broth as a basal medium supplemented with NaCl (5%), H2O2 (0.05%), sodium dodecyl sulfate (0.05%), amino acids (0.0281%), and urea (0.192%). The pH of the medium was adjusted to 8 and incubated for 24 h at 40°C. The GSH amount was increased by 10-fold (851%) using the optimized medium. Hence, our optimization design estimated the biotechnological potential of L. plantarum (L7) for the production of GSH in the industry. PMID:28536556

Comparison of plasma malondialdehyde, glutathione, glutathione peroxidase, hydroxyproline and selenium levels in patients with vitiligo and healthy controls

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Ozturk I

2008-01-01

Full Text Available Background: The etiology and pathophysiologic mechanism of vitiligo are still unclear. The relationship between increased oxidative stress due to the accumulation of radicals and reactive oxygen species and the associated changes in blood and epidermal component of vitiliginous skin have been reported many times. We investigated the possible changes of plasma malondialdehyde, glutathione, selenium, hydroxyproline and glutathione peroxidase activity levels in patients with vitiligo in order to evaluate the relationship between oxidative stress and etiopathogenesis of vitiligo. Materials and Methods: Plasma malondialdehyde, glutathione, hydroxyproline and glutathione peroxidase activity levels were measured by spectrophotometric methods, and HPLC was used for measurement of selenium concentrations. Results: Our results showed increased malondialdehyde, hydroxyproline and glutathione peroxidase activity levels in plasma of vitiligo group ( P < 0.05. Conclusion: Support of antioxidant system via nonenzymatic antioxidant compounds and antioxidant enzymes may be useful to prevent of melanocyte degeneration which occur due to oxidative damage in vitiligo.

Quantification of glutathione transverse relaxation time T2 using echo time extension with variable refocusing selectivity and symmetry in the human brain at 7 Tesla

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Swanberg, Kelley M.; Prinsen, Hetty; Coman, Daniel; de Graaf, Robin A.; Juchem, Christoph

2018-05-01

Glutathione (GSH) is an endogenous antioxidant implicated in numerous biological processes, including those associated with multiple sclerosis, aging, and cancer. Spectral editing techniques have greatly facilitated the acquisition of glutathione signal in living humans via proton magnetic resonance spectroscopy, but signal quantification at 7 Tesla is still hampered by uncertainty about the glutathione transverse decay rate T2 relative to those of commonly employed quantitative references like N-acetyl aspartate (NAA), total creatine, or water. While the T2 of uncoupled singlets can be derived in a straightforward manner from exponential signal decay as a function of echo time, similar estimation of signal decay in GSH is complicated by a spin system that involves both weak and strong J-couplings as well as resonances that overlap those of several other metabolites and macromolecules. Here, we extend a previously published method for quantifying the T2 of GABA, a weakly coupled system, to quantify T2 of the strongly coupled spin system glutathione in the human brain at 7 Tesla. Using full density matrix simulation of glutathione signal behavior, we selected an array of eight optimized echo times between 72 and 322 ms for glutathione signal acquisition by J-difference editing (JDE). We varied the selectivity and symmetry parameters of the inversion pulses used for echo time extension to further optimize the intensity, simplicity, and distinctiveness of glutathione signals at chosen echo times. Pairs of selective adiabatic inversion pulses replaced nonselective pulses at three extended echo times, and symmetry of the time intervals between the two extension pulses was adjusted at one extended echo time to compensate for J-modulation, thereby resulting in appreciable signal-to-noise ratio and quantifiable signal shapes at all measured points. Glutathione signal across all echo times fit smooth monoexponential curves over ten scans of occipital cortex voxels in nine

Endogenous salicylic acid is required for promoting cadmium tolerance of Arabidopsis by modulating glutathione metabolisms

International Nuclear Information System (INIS)

Guo, Bin; Liu, Chen; Li, Hua; Yi, Keke; Ding, Nengfei; Li, Ningyu; Lin, Yicheng; Fu, Qinglin

2016-01-01

Highlights: • The role of endogenous SA in mediating Cd tolerance was explored using sid2 mutants. • Cd stress induces SA accumulation in a SID2 dependent way. • Depletion of SA causes negative effects on Cd tolerance. • Endogenous SA is required for promoting Cd tolerance by modulating GSH metabolism. • Possible mode of SA signaling through GR/GSH pathway under Cd toxicity was discussed. - Abstract: A few studies with NahG transgenic lines of Arabidopsis show that depletion of SA enhances cadmium (Cd) tolerance. However, it remains some uncertainties that the defence signaling may be a result of catechol accumulation in NahG transgenic lines but not SA deficiency. Here, we conducted a set of hydroponic assays with another SA-deficient mutant sid2 to examine the endogenous roles of SA in Cd tolerance, especially focusing on the glutathione (GSH) cycling. Our results showed that reduced SA resulted in negative effects on Cd tolerance, including decreased Fe uptake and chlorophyll concentration, aggravation of oxidative damage and growth inhibition. Cd exposure significantly increased SA concentration in wild-type leaves, but did not affect it in sid2 mutants. Depletion of SA did not disturb the Cd uptake in either roots or shoots. The reduced Cd tolerance in sid2 mutants is due to the lowered GSH status, which is associated with the decreased expression of serine acetyltransferase along with a decline in contents of non-protein thiols, phytochelatins, and the lowered transcription and activities of glutathione reductase1 (GR1) which reduced GSH regeneration. Finally, the possible mode of SA signaling through the GR/GSH pathway during Cd exposure is discussed.

Endogenous salicylic acid is required for promoting cadmium tolerance of Arabidopsis by modulating glutathione metabolisms

Energy Technology Data Exchange (ETDEWEB)

Guo, Bin, E-mail: ndgb@163.com [Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Geological Research Center For Agricultural Applications, China Geological Survey, Hangzhou (China); Liu, Chen; Li, Hua [Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Geological Research Center For Agricultural Applications, China Geological Survey, Hangzhou (China); Yi, Keke [Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou (China); Ding, Nengfei; Li, Ningyu; Lin, Yicheng [Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Geological Research Center For Agricultural Applications, China Geological Survey, Hangzhou (China); Fu, Qinglin, E-mail: fuql161@yahoo.com.cn [Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Geological Research Center For Agricultural Applications, China Geological Survey, Hangzhou (China)

2016-10-05

Highlights: • The role of endogenous SA in mediating Cd tolerance was explored using sid2 mutants. • Cd stress induces SA accumulation in a SID2 dependent way. • Depletion of SA causes negative effects on Cd tolerance. • Endogenous SA is required for promoting Cd tolerance by modulating GSH metabolism. • Possible mode of SA signaling through GR/GSH pathway under Cd toxicity was discussed. - Abstract: A few studies with NahG transgenic lines of Arabidopsis show that depletion of SA enhances cadmium (Cd) tolerance. However, it remains some uncertainties that the defence signaling may be a result of catechol accumulation in NahG transgenic lines but not SA deficiency. Here, we conducted a set of hydroponic assays with another SA-deficient mutant sid2 to examine the endogenous roles of SA in Cd tolerance, especially focusing on the glutathione (GSH) cycling. Our results showed that reduced SA resulted in negative effects on Cd tolerance, including decreased Fe uptake and chlorophyll concentration, aggravation of oxidative damage and growth inhibition. Cd exposure significantly increased SA concentration in wild-type leaves, but did not affect it in sid2 mutants. Depletion of SA did not disturb the Cd uptake in either roots or shoots. The reduced Cd tolerance in sid2 mutants is due to the lowered GSH status, which is associated with the decreased expression of serine acetyltransferase along with a decline in contents of non-protein thiols, phytochelatins, and the lowered transcription and activities of glutathione reductase1 (GR1) which reduced GSH regeneration. Finally, the possible mode of SA signaling through the GR/GSH pathway during Cd exposure is discussed.

Reaction between nitracrine and glutathione: implications for hypoxic cell radiosensitization and cytotoxicity

International Nuclear Information System (INIS)

Wilson, W.R.; Anderson, R.F.

1989-01-01

Nitracrine (NC) is an electron affinic DNA intercalating agent and a potent hypoxia-selective cytotoxin and radiosensitizer in cell culture. Although NC is too cytotoxic and too rapidly metabolized to provide hypoxic cell radiosensitization in tumors, it is of mechanistic interest as an example of a DNA affinic radiosensitizer. We have observed a rapid chemical reaction between NC and reduced glutathione (GSH), which suggests that the observed potent in vitro cytotoxicity and radiosensitization might be dependent on thiol depletion by the large extracellular reservoir of drug. However, no GSH depletion was observed under conditions providing radiosensitization or rapid cell killing, and prior depletion of GSH by buthionine sulphoximine had no effect on cytotoxicity or formation of macromolecular adducts. Further, the intracellular reaction of NC with GSH is slower than predicted on the basis of the measured second order rate constant and the total intracellular concentrations of both species. The results are consistent with a role for DNA binding in protecting NC from reaction with GSH, and in improving the efficiency with which reduced electrophilic metabolites react with DNA in preference to GSH

Analysis of manganese superoxide dismutase (MnSOD: Ala-9Val and glutathione peroxidase (GSH-Px: Pro 197 Leu gene polymorphisms in mood disorders.

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Birgül Elbozan Cumurcu

2013-05-01

Full Text Available We investigated the etiopathogenetic role of manganese superoxide dismutase (MnSOD (Ala-9Val and glutathione peroxidase (GSH-Px (Pro 197 Leu gene polymorphisms in patients diagnosed with major depressive disorder (MDD and bipolar I disorder (BD. Eighty patients with MDD, 82 patients with BD (total 162 patients and 96 healthy controls were enrolled in this study and genotyped using a Real Time-Quantitative Polymer Chain Reaction (RT-qPCR-based method. The patients with BD and MDD and the controls had a similar distribution of the genotypes and alleles in the Ala-9Val MnSOD gene polymorphism. Comparison of the MDD group and control group regarding the Pro197 Leu GSH-Px gene polymorphism revealed similar genotype distribution but different allele distribution. The BD group and control group were similar both for genotypes and for alleles when compared regarding the Pro 197 Leu GSH-Px gene polymorphism. The combined analysis (MDD plus BD also failed to find any association between the Ala-9Val MnSOD and Pro 197 Leu GSH-Px gene polymorphism. Although small statistical power of the current study the significant difference between patients with depression and the control group for the Pro 197 Leu GSH-Px polymorphism indicates that the distribution of these alleles may have a contribution in the physiopathogenesis of depression. One of the limitation of the current study is that the sample size is too small. Understanding of the exact role of Pro 197 LeuGSH-Px polymorphism in the development of depression needs to further studies with more sample size and high statistical power.

Effect of rosemary (Rosmarinus officinalis) extracts and glutathione antioxidants on bull semen quality after cryopreservation

Energy Technology Data Exchange (ETDEWEB)

Daghigh-Kia, H.; Olfati-Karaji, R.; Hoseinkhani, A.; Ashrafi, I.

2014-06-01

The present study determined the effects of the addition of rosemary extract (ROM), glutathione (GSH), and their combination (ROM + GSH) to freezing extender on the quality of bull semen after cryopreservation. Before cryoperservation, the samples were diluted in a tris-egg yolk (TEY) extender containing 5 mM GSH (treatment I), 5 or 10 g L{sup -}1 ROM (treatments II and III), and ROM with GSH (5 mM GSH with 5 or 10 g L{sup -}1 of ROM) (treatments IV and V). An extender containing no antioxidants (non-ROM/GSH-treated) served as control group. Kinematic parameters were evaluated by means of a computer-assisted semen analysis (CASA). The viability and membrane integrity of the sperm were assessed using eosin-nigrosin stain and the hypo-osmotic swelling test (HOST) at 0 and 2 h after freezethawing. Lipooxidative parameters, superoxide dismutase, and glutathione peroxidase (GPx) activity were assessed after thawing. Treatment III showed positive effects for total motility (TM) (p < 0.01), average path velocity (VAP) (p < 0.001), viability (p < 0.01) and HOST (p < 0.01); however, lipid peroxidation (LPO) decreased (p < 0.05) and GPx activity increased (p < 0.05) immediately after thawing compared to the control. The TM (p < 0.01), VAP (p < 0.01), viability (p < 0.01), HOST (p < 0.01) decreased in LPO (p < 0.01) and GPx activity (p < 0.05) for treatment V and the viability and GPx activity (p < 0.05) for treatment I were significantly higher than for the control group at 2 h after thawing. It was concluded that the inclusion of ROM and its combination with GSH improves the post-thaw quality of bull semen. (Author)

Acute effects of heavy metals on the expression of glutathione-related antioxidant genes in the marine ciliate Euplotes crassus

International Nuclear Information System (INIS)

Kim, Se-Hun; Kim, Se-Joo; Lee, Jae-Seong; Lee, Young-Mi

2014-01-01

Highlights: • Significant higher increases in the relative ROS and total GSH levels were observed after exposure to heavy metals. • Real-time PCR data showed expression levels of GPx and GR mRNA were sensitively modulated within 8 h of exposure to heavy metals. • E. crassus GPx and GR genes may be involved in cellular defense mechanisms against heavy metal-induced oxidative stress. • E. crassus GPx and GR genes will be useful as potential molecular markers for monitoring heavy metal contamination. - Abstract: Euplotes crassus, a single-celled eukaryote, is directly affected by environmental contaminants. Here, exponentially cultured E. crassus were exposed to cadmium, copper, lead, and zinc and then the reactive oxygen species (ROS) and total glutathione (GSH) levels were measured. Subsequently, the transcriptional modulation of glutathione peroxidase (GPx) and glutathione reductase (GR) were estimated by quantitative RT-PCR. After an 8-h exposure, significantly higher increases in the relative ROS and total GSH levels were observed in exposed group, compared to the controls. Real-time PCR data revealed that the expression levels of GPx and GR mRNA were sensitively modulated within 8 h of exposure to all heavy metals. These findings suggest that these genes may be involved in cellular defense mechanisms by modulating their gene expression against heavy metal-induced oxidative stress. Thus, they may be useful as potential molecular biomarkers to assess sediment environments for contaminants

Glutathione S-Transferases: Role in Combating Abiotic Stresses Including Arsenic Detoxification in Plants

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Smita Kumar

2018-06-01

Full Text Available Arsenic (As, naturally occurring metalloid and a potential hazardous material, is found in low concentrations in the environment and emerges from natural sources and anthropogenic activities. The presence of As in ground water, which is used for irrigation, is a matter of great concern since it affects crop productivity and contaminates food chain. In plants, As alters various metabolic pathways in cells including the interaction of substrates/enzymes with the sulfhydryl groups of proteins and the replacement of phosphate in ATP for energy. In addition, As stimulates the generation of free radicals and reactive oxygen species (ROS, resulting in oxidative stress. Glutathione S-transferases (GSTs quench reactive molecules with the addition of glutathione (GSH and protect the cell from oxidative damage. GSTs are a multigene family of isozymes, known to catalyze the conjugation of GSH to miscellany of electrophilic and hydrophobic substrates. GSTs have been reported to be associated with plant developmental processes and are responsive to multitude of stressors. In past, several studies suggested involvement of plant GST gene family in As response due to the requirement of sulfur and GSH in the detoxification of this toxic metalloid. This review provides updated information about the role of GSTs in abiotic and biotic stresses with an emphasis on As uptake, metabolism, and detoxification in plants. Further, the genetic manipulations that helped in enhancing the understanding of the function of GSTs in abiotic stress response and heavy metal detoxification has been reviewed.

The Comparison of One-Session Intensive Aerobic Exercise Effects on Glutathione Redox State of Red Blood Cells in Professional, Recreational Athletes and Nonathletes

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Farnaz Seifi-Skishahr

2015-04-01

Full Text Available Background & objectives: The “redox” state represents the oxidation/reduction potential within the cell in a way that more “redox” is the marker of health, while the more oxidized reflects predisposition to diseases. Different types of exercise training may change the thiol/disulfide ratio of redox couples such as glutathione and represent a shift in redox balance. This study was assessed the influence of high-intensity aerobic exercise on glutathione redox state in red blood cells in professional, recreational athletes and nonathletes.   Methods: Ten voluntary well trained (WT, moderately trained (MT and untrained men subjectswere randomly selected for this semi-experimental study (mean ages of 21.10±1.72 21.70±1.88 and 20.10±1.44, respectively. Blood samples were collected before, immediately, 10 min and 30 min after acute aerobic exercise with 75%VO2max. The levels of reduced glutathione (GSH, oxidized glutathione (GSSG and (GSH/GSSG in red blood cells (RBCs as well as serum levels of cortisol and creatine kinase (CK were measured.   Results: The results showed reduction, elevation and no changes in RBCs GSH/GSSG ratio in UT, MT and WT groups, respectively. The lowest levels of GSH/GSSG ratio in RBCs and the highest one were detected in the WT and MT groups, respectively. The serum levels of cortisol and creatine kinase were increased following the exercise in three groups.   Conclusion: It is concluded that acute aerobic exercise with high intensity does not change redox balance in well trained subjects, however it is capable to shift redox balance towards more reducing environment in moderately trained subjects and also to more oxidizing one in untrained subjects.

The evolution of glutathione metabolism in phototrophic microorganisms

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Fahey, R. C.; Buschbacher, R. M.; Newton, G. L.

1987-01-01

Of the many roles ascribed to glutathione (GSH) the one most clearly established is its role in the protection of higher eucaryotes against oxygen toxicity through destruction of thiol-reactive oxygen byproducts. If this is the primary function of GSH then GSH metabolism should have evolved during or after the evolution of oxygenic photosynthesis. That many bacteria do not produce GSH is consistent with this view. In the present study we have examined the low-molecular-weight thiol composition of a variety of phototrophic microorganisms to ascertain how evolution of GSH production is related to evolution of oxygenic photosynthesis. Cells were extracted in the presence of monobromobimane (mBBr) to convert thiols to fluorescent derivatives, which were analyzed by high-pressure liquid chromatography. Significant levels of GSH were not found in the green bacteria (Chlorobium thiosulfatophilum and Chloroflexus aurantiacus). Substantial levels of GSH were present in the purple bacteria (Chromatium vinosum, Rhodospirillum rubrum, Rhodobacter sphaeroides, and Rhodocyclus gelatinosa), the cyanobacteria [Anacystis nidulans, Microcoleus chthonoplastes S.G., Nostoc muscorum, Oscillatoria amphigranulata, Oscillatoria limnetica, Oscillatoria sp. (Stinky Spring, Utah), Oscillatoria terebriformis, Plectonema boryanum, and Synechococcus lividus], and eucaryotic algae (Chlorella pyrenoidsa, Chlorella vulgaris, Euglena gracilis, Scenedesmus obliquus, and Chlamydomonas reinhardtii). Other thiols measured included cysteine, gamma-glutamylcysteine, thiosulfate, coenzyme A, and sulfide; several unidentified thiols were also detected. Many of the organisms examined also exhibited a marked ability to reduce mBBr to syn-(methyl,methyl)bimane, an ability that was quenched by treatment with 2-pyridyl disulfide or 5,5'-bisdithio-(2-nitrobenzoic acid) prior to reaction with mBBr. These observations indicate the presence of a reducing system capable of electron transfer to mBBr and reduction of

Heterogeneous role of the glutathione antioxidant system in modulating the response of ESFT to fenretinide in normoxia and hypoxia.

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Tapiwanashe Magwere

Full Text Available Glutathione (GSH is implicated in drug resistance mechanisms of several cancers and is a key regulator of cell death pathways within cells. We studied Ewing's sarcoma family of tumours (ESFT cell lines and three mechanistically distinct anticancer agents (fenretinide, doxorubicin, and vincristine to investigate whether the GSH antioxidant system is involved in the reduced sensitivity to these chemotherapeutic agents in hypoxia. Cell viability and death were assessed by the trypan blue exclusion assay and annexin V-PI staining, respectively. Hypoxia significantly decreased the sensitivity of all ESFT cell lines to fenretinide-induced death, whereas the effect of doxorubicin or vincristine was marginal and cell-line-specific. The response of the GSH antioxidant system in ESFT cell lines to hypoxia was variable and also cell-line-specific, although the level of GSH appeared to be most dependent on de novo biosynthesis rather than recycling. RNAi-mediated knockdown of key GSH regulatory enzymes γ-glutamylcysteine synthetase or glutathione disulfide reductase partially reversed the hypoxia-induced resistance to fenretinide, and increasing GSH levels using N-acetylcysteine augmented the hypoxia-induced resistance in a cell line-specific manner. These observations are consistent with the conclusion that the role of the GSH antioxidant system in modulating the sensitivity of ESFT cells to fenretinide is heterogeneous depending on environment and cell type. This is likely to limit the value of targeting GSH as a therapeutic strategy to overcome hypoxia-induced drug resistance in ESFT. Whether targeting the GSH antioxidant system in conjunction with other therapeutics may benefit some patients with ESFT remains to be seen.

Mechanistic insights into EgGST1, a Mu class glutathione S-transferase from the cestode parasite Echinococcus granulosus.

Science.gov (United States)

Arbildi, Paula; Turell, Lucía; López, Verónica; Alvarez, Beatriz; Fernández, Verónica

2017-11-01

Glutathione transferases (GSTs) comprise a major detoxification system in helminth parasites, displaying both catalytic and non-catalytic activities. The kinetic mechanism of these enzymes is complex and depends on the isoenzyme which is being analyzed. Here, we characterized the kinetic mechanism of rEgGST1, a recombinant form of a cytosolic GST from Echinococcus granulosus (EgGST1), which is related to the Mu-class of mammalian enzymes, using the canonical substrates glutathione (GSH) and 1-chloro-2,4-dinitrobenzene (CDNB). Initial rate and product inhibition studies were consistent with a steady-state random sequential mechanism, where both substrates are bound to the enzyme before the products are released. Kinetic constants were also determined (pH 6.5 and 30 °C). Moreover, rEgGST1 lowered the pK a of GSH from 8.71 ± 0.07 to 6.77 ± 0.08, and enzyme-bound GSH reacted with CDNB 1 × 10 5 times faster than free GSH at pH 7.4. Finally, the dissociation of the enzyme-GSH complex was studied by means of intrinsic fluorescence, as well as that of the complex with the anthelminth drug mebendazole. This is the first report on mechanistic issues related to a helminth parasitic GST. Copyright © 2017 Elsevier Inc. All rights reserved.

Role of glutathione in immunity and inflammation in the lung

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Pietro Ghezzi

2011-01-01

Full Text Available Pietro GhezziBrighton and Sussex Medical School, Trafford Centre, Falmer, Brighton, UKAbstract: Reactive oxygen species and thiol antioxidants, including glutathione (GSH, regulate innate immunity at various levels. This review outlines the redox-sensitive steps of the cellular mechanisms implicated in inflammation and host defense against infection, and describes how GSH is not only important as an antioxidant but also as a signaling molecule. There is an extensive literature of the role of GSH in immunity. Most reviews are biased by an oversimplified picture where “bad” free radicals cause all sorts of diseases and “good” antioxidants protect from them and prevent oxidative stress. While this may be the case in certain fields (eg, toxicology, the role of thiols (the topic of this review in immunity certainly requires wearing scientist’s goggles and being prepared to accept a more complex picture. This review aims at describing the role of GSH in the lung in the context of immunity and inflammation. The first part summarizes the history and basic concepts of this picture. The second part focuses on GSH metabolism/levels in pathology, the third on the role of GSH in innate immunity and inflammation, and the fourth gives 4 examples describing the importance of GSH in the response to infections.Keywords: antioxidants, oxidative stress, sepsis, infection, cysteine

Evaluation of the photophysicochemical properties and photodynamic therapy activity of nanoconjugates of zinc phthalocyanine linked to glutathione capped Au and Au3Ag1 nanoparticles

CSIR Research Space (South Africa)

Oluwole, DA

2018-03-01

Full Text Available , Charles Maphanga, Saturnin Ombinda-Lemboumba, Patience Mthunzi-Kufa, Tebello Nyokong ABSTRACT: We report on the synthesis of glutathione capped gold (AuNPs–GSH) and gold– silver (Au3Ag1NPs–GSH) nanoparticles and their covalent attachment to Zn...

A review of the evidence concerning hepatic glutathione depletion and susceptibility to hepatotoxicity after paracetamol overdose

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Kalsi SS

2011-12-01

there have been few studies which have specifically investigated whether there is an association between reduced intrahepatic glutathione concentrations and increased risk of paracetamol-related hepatotoxicity, in our opinion, it is likely that the above conditions that are associated with reduced glutathione concentrations, will be associated with an increased risk of paracetamol-related hepatotoxicity.Keywords: glutathione, GSH, paracetamol, acetaminophen, hepatotoxicity, NAPQI

Glutathione aerosol suppresses lung epithelial surface inflammatory cell-derived oxidants in cystic fibrosis.

Science.gov (United States)

Roum, J H; Borok, Z; McElvaney, N G; Grimes, G J; Bokser, A D; Buhl, R; Crystal, R G

1999-07-01

Cystic fibrosis (CF) is characterized by accumulation of activated neutrophils and macrophages on the respiratory epithelial surface (RES); these cells release toxic oxidants, which contribute to the marked epithelial derangements seen in CF. These deleterious consequences are magnified, since reduced glutathione (GSH), an antioxidant present in high concentrations in normal respiratory epithelial lining fluid (ELF), is deficient in CF ELF. To evaluate the feasibility of increasing ELF GSH levels and enhancing RES antioxidant protection, GSH aerosol was delivered (600 mg twice daily for 3 days) to seven patients with CF. ELF total, reduced, and oxidized GSH increased (P < 0.05, all compared with before GSH therapy), suggesting adequate RES delivery and utilization of GSH. Phorbol 12-myristate 13-acetate-stimulated superoxide anion (O2-.) release by ELF inflammatory cells decreased after GSH therapy (P < 0.002). This paralleled observations that GSH added in vitro to CF ELF inflammatory cells suppressed O2-. release (P < 0.001). No adverse effects were noted during treatment. Together, these observations demonstrate the feasibility of using GSH aerosol to restore RES oxidant-antioxidant balance in CF and support the rationale for further clinical evaluation.

Role of glutathione biosynthesis in endothelial dysfunction and fibrosis.

Science.gov (United States)

Espinosa-Díez, Cristina; Miguel, Verónica; Vallejo, Susana; Sánchez, Francisco J; Sandoval, Elena; Blanco, Eva; Cannata, Pablo; Peiró, Concepción; Sánchez-Ferrer, Carlos F; Lamas, Santiago

2018-04-01

Glutathione (GSH) biosynthesis is essential for cellular redox homeostasis and antioxidant defense. The rate-limiting step requires glutamate-cysteine ligase (GCL), which is composed of the catalytic (GCLc) and the modulatory (GCLm) subunits. To evaluate the contribution of GCLc to endothelial function we generated an endothelial-specific Gclc haplo-insufficient mouse model (Gclc e/+ mice). In murine lung endothelial cells (MLEC) derived from these mice we observed a 50% reduction in GCLc levels compared to lung fibroblasts from the same mice. MLEC obtained from haplo-insufficient mice showed significant reduction in GSH levels as well as increased basal and stimulated ROS levels, reduced phosphorylation of eNOS (Ser 1177) and increased eNOS S-glutathionylation, compared to MLEC from wild type (WT) mice. Studies in mesenteric arteries demonstrated impaired endothelium-dependent vasodilation in Gclc(e/+) male mice, which was corrected by pre-incubation with GSH-ethyl-ester and BH 4 . To study the contribution of endothelial GSH synthesis to renal fibrosis we employed the unilateral ureteral obstruction model in WT and Gclc(e/+) mice. We observed that obstructed kidneys from Gclc(e/+) mice exhibited increased deposition of fibrotic markers and reduced Nrf2 levels. We conclude that the preservation of endothelial GSH biosynthesis is not only critical for endothelial function but also in anti-fibrotic responses. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Active biomonitoring of a subtropical river using glutathione-S ...

African Journals Online (AJOL)

Active biomonitoring of a subtropical river using glutathione-S-transferase (GST) and heat shock proteins (HSP 70) in. Oreochromis niloticusas surrogate biomarkers of metal contamination. Victor Kurauone Muposhi1, Beaven Utete1*, Idah Sithole-Niang2 and Stanley Mukangenyama2. 1Wildlife Ecology and Conservation, ...

Reduced repair of potentially lethal radiation damage in glutathione synthetase-deficient human fibroblasts after X-irradiation

International Nuclear Information System (INIS)

Midander, J.; Revesz, L.; Deschavanne, P.J.; Debieu, D.; Malaise, E.P.

1986-01-01

Using a human fibroblast strain deficient in glutathione synthetase and a related proficient control strain, the role of glutathione (GSH) in repair of potentially lethal damage (PLD) has been investigated in determining survival by plating cells immediately or 24 h after irradiation. After oxic or hypoxic irradiation, both cell strains repair radiation-induced damage. However, under hypoxic conditions, the proficient cells repair PLD as well as under oxic conditions while the deficient cells repair less PLD after irradiation under hypoxic than under oxic conditions. Therefore, the oxygen enhancement ratio (o.e.r.) for proficient cells is similar whether the cells are plated immediately or 24 h later (2.0 and 2.13, respectively). In contrast, the o.e.r. for deficient cells is lower when the cells are plated 24 h after irradiation than when they are plated immediately thereafter (1.16 as compared to 1.55). The results indicate that GSH is involved in PLD repair and, in particular, in the repair of damage induced by radiation delivered under hypoxic conditions. (author)

Study the interaction between CdTe-glutathione and human serum albumin

Energy Technology Data Exchange (ETDEWEB)

Yang, Qing; Zhou, Xi-min; Zhu, Yi-shuo [National Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen, Xing-guo, E-mail: chenxg@lzu.edu.cn [National Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China)

2013-03-15

In this paper, glutathione (GSH) modified CdTe quantum dots (CdTe-GSH QDs) were synthesized in an aqueous solution. Then, the binding of the CdTe-GSH QDs to human serum albumin (HSA) was studied using the fluorescence spectroscopy. The quenching mechanism was investigated in terms of the association constants and basic thermodynamic parameters. The fluorescence data revealed that CdTe-GSH QDs could quench the intrinsic fluorescence of human serum albumin by a static quenching mechanism. Furthermore, alteration of the secondary protein structure in the presence of the QDs was confirmed by synchronous fluorescence spectra. - Highlights: Black-Right-Pointing-Pointer In this paper, the binding of the CdTe-GSH QDs to human serum albumin (HSA) was studied using a fluorescence spectroscopy. Black-Right-Pointing-Pointer The quenching mechanism was investigated in terms of the association constants and basic thermodynamic parameters. Black-Right-Pointing-Pointer Furthermore, alteration of the secondary protein structure in the presence of the QDs was confirmed by synchronous fluorescence spectra. Black-Right-Pointing-Pointer The research can help us assess biological toxicity of QDs and further expand the application scope of QDs.

L-cysteine supplementation upregulates glutathione (GSH) and vitamin D binding protein (VDBP) in hepatocytes cultured in high glucose and in vivo in liver, and increases blood levels of GSH, VDBP, and 25-hydroxy-vitamin D in Zucker diabetic fatty rats.

Science.gov (United States)

Jain, Sushil K; Kanikarla-Marie, Preeti; Warden, Cassandra; Micinski, David

2016-05-01

Vitamin D binding protein (VDBP) status has an effect on and can potentially improve the status of 25(OH) vitamin D and increase the metabolic actions of 25(OH) vitamin D under physiological and pathological conditions. Diabetes is associated with lower levels of glutathione (GSH) and 25(OH) vitamin D. This study examined the hypothesis that upregulation of GSH will also upregulate blood levels of VDBP and 25(OH) vitamin D in type 2 diabetic rats. L-cysteine (LC) supplementation was used to upregulate GSH status in a FL83B hepatocyte cell culture model and in vivo using Zucker diabetic fatty (ZDF) rats. Results show that LC supplementation upregulates both protein and mRNA expression of VDBP and vitamin D receptor (VDR) and GSH status in hepatocytes exposed to high glucose, and that GSH deficiency, induced by glutamate cysteine ligase knockdown, resulted in the downregulation of GSH, VDBP, and VDR and an increase in oxidative stress levels in hepatocytes. In vivo, LC supplementation increased GSH and protein and mRNA expression of VDBP and vitamin D 25-hydroxylase (CYP2R1) in the liver, and simultaneously resulted in elevated blood levels of LC and GSH, as well as increases in VDBP and 25(OH) vitamin D levels, and decreased inflammatory biomarkers in ZDF rats compared with those in placebo-supplemented ZDF rats consuming a similar diet. LC supplementation may provide a novel approach by which to raise blood levels of VDBP and 25(OH) vitamin D in type 2 diabetes. © 2016 The Authors. Molecular Nutrition & Food Research Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Intracellular Glutathione Depletion by Oridonin Leads to Apoptosis in Hepatic Stellate Cells

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Liang-Mou Kuo

2014-03-01

Full Text Available Proliferation of hepatic stellate cells (HSCs plays a key role in the pathogenesis of liver fibrosis. Induction of HSC apoptosis by natural products is considered an effective strategy for treating liver fibrosis. Herein, the apoptotic effects of 7,20-epoxy-ent-kaurane (oridonin, a diterpenoid isolated from Rabdosia rubescens, and its underlying mechanisms were investigated in rat HSC cell line, HSC-T6. We found that oridonin inhibited cell viability of HSC-T6 in a concentration-dependent manner. Oridonin induced a reduction in mitochondrial membrane potential and increases in caspase 3 activation, subG1 phase, and DNA fragmentation. These apoptotic effects of oridonin were completely reversed by thiol antioxidants, N-acetylcysteine (NAC and glutathione monoethyl ester. Moreover, oridonin increased production of reactive oxygen species (ROS, which was also inhibited by NAC. Significantly, oridonin reduced intracellular glutathione (GSH level in a concentration- and time-dependent fashion. Additionally, oridonin induced phosphorylations of extracellular signal-regulated kinase (ERK, c-Jun N-terminal kinase (JNK, and p38 mitogen-activated protein kinase (MAPK. NAC prevented the activation of MAPKs in oridonin-induced cells. However, selective inhibitors of MAPKs failed to alter oridonin-induced cell death. In summary, these results demonstrate that induction of apoptosis in HSC-T6 by oridonin is associated with a decrease in cellular GSH level and increase in ROS production.

Membrane accessibility of glutathione

DEFF Research Database (Denmark)

Garcia, Almudena; Eljack, N., D.; Sani, ND

2015-01-01

Regulation of the ion pumping activity of the Na(+),K(+)-ATPase is crucial to the survival of animal cells. Recent evidence has suggested that the activity of the enzyme could be controlled by glutathionylation of cysteine residue 45 of the β-subunit. Crystal structures so far available indicate...... that this cysteine is in a transmembrane domain of the protein. Here we have analysed via fluorescence and NMR spectroscopy as well as molecular dynamics simulations whether glutathione is able to penetrate into the interior of a lipid membrane. No evidence for any penetration of glutathione into the membrane...

Thiol-Disulfide Exchange between Glutaredoxin and Glutathione

DEFF Research Database (Denmark)

Iversen, Rasmus; Andersen, Peter Anders; Jensen, Kristine Steen

2010-01-01

Glutaredoxins are ubiquitous thiol-disulfide oxidoreductases which catalyze the reduction of glutathione-protein mixed disulfides. Belonging to the thioredoxin family, they contain a conserved active site CXXC motif. The N-proximal active site cysteine can form a mixed disulfide with glutathione ...... has been replaced with serine. The exchange reaction between the reduced protein and oxidized glutathione leading to formation of the mixed disulfide could readily be monitored by isothermal titration calorimetry (ITC) due to the enthalpic contributions from the noncovalent interactions...

Sodium nitroprusside induces autophagic cell death in glutathione-depleted osteoblasts.

Science.gov (United States)

Son, Min Jeong; Lee, Seong-Beom; Byun, Yu Jeong; Lee, Hwa Ok; Kim, Ho-Shik; Kwon, Oh-Joo; Jeong, Seong-Whan

2010-01-01

Previous studies reported that high levels of nitric oxide (NO) induce apoptotic cell death in osteoblasts. We examined molecular mechanisms of cytotoxic injury induced by sodium nitroprusside (SNP), a NO donor, in both glutathione (GSH)-depleted and control U2-OS osteoblasts. Cell viability was reduced by much lower effective concentrations of SNP in GSH-depleted cells compared to normal cells. The data suggest that the level of intracellular GSH is critical in SNP-induced cell death processes of osteoblasts. The level of oxidative stress due to SNP treatments doubled in GSH-depleted cells when measured with fluorochrome H2DCFDA. Pretreatment with the NO scavenger PTIO preserved the viability of cells treated with SNP. Viability of cells treated with SNP was recovered by pretreatment with Wortmannin, an autophagy inhibitor, but not by pretreatment with zVAD-fmk, a pan-specific caspase inhibitor. Large increases of LC3-II were shown by immunoblot analysis of the SNP-treated cells, and the increase was blocked by pretreatment with PTIO or Wortmannin; this implies that under GSH-depleted conditions SNP induces different molecular signaling that lead to autophagic cell death. The ultrastructural morphology of SNP-treated cells in transmission electron microscopy showed numerous autophagic vacuoles. These data suggest NO produces oxidative stress and cellular damage that culminate in autophagic cell death of GSH-depleted osteoblasts. Copyright 2010 Wiley Periodicals, Inc.

Susceptibility of human head and neck cancer cells to combined inhibition of glutathione and thioredoxin metabolism.

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Arya Sobhakumari

Full Text Available Increased glutathione (GSH and thioredoxin (Trx metabolism are mechanisms that are widely implicated in resistance of cancer cells to chemotherapy. The current study determined if simultaneous inhibition of GSH and Trx metabolism enhanced cell killing of human head and neck squamous cell carcinoma (HNSCC cells by a mechanism involving oxidative stress. Inhibition of GSH and Trx metabolism with buthionine sulfoximine (BSO and auranofin (AUR, respectively, induced significant decreases in clonogenic survival compared to either drug alone in FaDu, Cal-27 and SCC-25 HNSCC cells in vitro and in vivo in Cal-27 xenografts. BSO+AUR significantly increased glutathione and thioredoxin oxidation and suppressed peroxiredoxin activity in vitro. Pre-treatment with N-acetylcysteine completely reversed BSO+AUR-induced cell killing in FaDu and Cal-27 cells, while catalase and selenium supplementation only inhibited BSO+AUR-induced cell killing in FaDu cells. BSO+AUR decreased caspase 3/7 activity in HNSCC cells and significantly reduced the viability of both Bax/Bak double knockout (DKO and DKO-Bax reconstituted hematopoietic cells suggesting that necrosis was involved. BSO+AUR also significantly sensitized FaDu, Cal-27, SCC-25 and SQ20B cells to cell killing induced by the EGFR inhibitor Erlotinib in vitro. These results support the conclusion that simultaneous inhibition of GSH and Trx metabolism pathways induces oxidative stress and clonogenic killing in HNSCCs and this strategy may be useful in sensitizing HNSCCs to EGFR inhibitors.

Detection of glutathione based on MnO2 nanosheet-gated mesoporous silica nanoparticles and target induced release of glucose measured with a portable glucose meter.

Science.gov (United States)

Tan, Qingqing; Zhang, Ruirui; Kong, Rongmei; Kong, Weisu; Zhao, Wenzhi; Qu, Fengli

2017-12-08

The authors describe a novel method for the determination of glutathione (GSH). Detection is based on target induced release of glucose from MnO 2 nanosheet-gated aminated mesoporous silica nanoparticles (MSNs). In detail, glucose is loaded into the pores of MSNs. Negatively charged MnO 2 nanosheets are assembled on the MSNs through electrostatic interactions. The nanosheets are reduced by GSH, and this results in the release of glucose which is quantified by using a commercial electrochemical glucose meter. GSH can be quantified by this method in the 100 nM to 10 μM concentration range, with a 34 nM limit of detection. Graphical abstract Glucose is loaded into the pores of mesoporous silica nanoparticles (MSNs). MnO 2 nanosheets are assembled on MSNs through electrostatic interactions. Glutathione (GSH) can reduce the nanosheets, and this results in the release of glucose which is quantified by using a commercial glucose meter.

Human glutathione S-transferase-mediated glutathione conjugation of curcumin and efflux of these conjugates in Caco-2 cells

NARCIS (Netherlands)

Usta, M.; Wortelboer, H.M.; Vervoort, J.J.M.; Boersma, M.G.; Rietjens, I.M.C.M.; Bladeren, van P.J.; Cnubben, N.H.P.

2007-01-01

Curcumin, an alpha,beta-unsaturated carbonyl compound, reacts with glutathione, leading to the formation of two monoglutathionyl curcumin conjugates. In the present study, the structures of both glutathione conjugates of curcumin were identified by LC-MS and one- and two-dimensional H-1 NMR

The role of BCL-2 and glutathione in an antioxidant pathway to prevent radiation-induced apoptosis

International Nuclear Information System (INIS)

Vlachaki, Maria T.; Meyn, Raymond E.

1997-01-01

Objective: The expression of the bcl-2 gene has been associated with resistance to radiation induced apoptosis. There is evidence that the bcl-2 protein acts in the antioxidant pathways to block the effects of reactive oxygen spieces that mediate apoptosis possibly by increasing the levels of intracellular glutathione. Our hypothesis is that pretreatment of radiation-sensitive cells, known to lack bcl-2 expression, with antioxidants will reduce radiation-induced apoptosis. For this purpose, the apoptotic response to radiation and the intracellular levels of glutathione were tested before and after pretreatment with antioxidants in two murine lymphoma cell lines, a radiation resistant-bcl-2 expressing (Ly-ar) line and a radiation sensitive (Ly-as) line. Methods and Materials: Ly-ar and Ly-as cells were irradiated at 0,1,2,3 and 4 hours before collection. The intracellular levels of reduced (GSH) and oxidized (GSSG) glutathione were determined by the use of the fluorescent dye ophthalaldehyde. Ly-as cells were pretreated with dihydrolipoic acid and lipoamide for 1 hour before irradiation. Apoptosis response was measured by the DNA fragmentation assay. The radiation dose was 2.5 Gy. Results: After irradiation, the apoptotic rate of Ly-ar and Ly-as cells is 11-19% and 66-87% respectively. Ly-ar cells have higher intracellular GSH and GSSG levels compared to Ly-as cells by 69.9% and 91.9% respectively and the GSH/GSSG ratio in Ly-ar and Ly-as cells is 17.09 and 15.09 respectively (a difference of 13.25%). GSH levels do not change during the first three hours after irradiation; however there is a 46% reduction at four hours after irradiation, a time at which the Ly-as cells have already fragmented their DNA. Pretreatment of cells with dihydrolipoic acid or lipoamide at concentrations of 4mM and 2mM respectively was toxic and resulted in cell death in the absence of irradiation. Conclusions: GSH and GSSG levels are elevated in radiation-resistant murine lymphoma cells

Levels of glutathione and 2,3-diphosphoglycerate in the red blood cells of Australian Aborigines.

Science.gov (United States)

Agar, N S

1980-01-01

There were no significant differences in packed cell volume (PCV) and red cell 2,3-diphosphoglycerate (2,3-DPG) levels in Australian Aborigines and Caucasians. A highly significant negative correlation was found between PCV and 2,3-DPG in both Aborigines (r = 0.251; n = 231) and Caucasians (r = 0.435; n = 227). Levels of reduced glutathione (GSH) in the red blood cells of Aborigines were significantly lower (P < 0.001) compared to those of Caucasians. There was a significant negative correlation between PCV and GSH in both the groups; (Aborigines r = -0.637, n = 115; Caucasians r = 0.388, n = 111).

Highly selective detection of glutathione using a NIP/Cu2+ complex fluorescent probe

International Nuclear Information System (INIS)

Liang Wenrui; Zhao Zhi; Zhang Yang; Wang Qiusheng; Zhao Xin; Ouyang Jie

2012-01-01

A novel fluorescent compound, 4-(trimethyl ammonium chloride)acetamide-2-(1H-naphtho[2,3-d]imidazol-2-yl)phenol (TMACA-NIP), was synthesized and used as a fluorescent probe for detecting glutathione reduced (GSH). The new NIP-based probe exhibited high fluorescence in water, which was quenched during the presence of copper (II) due to the complexation between TMACA-NIP and Cu 2+ . But after adding GSH into the TMACA-NIP and Cu 2+ system, the fluorescence of TMACA-NIP was recovered because the binding force between GSH and Cu 2+ is stronger than that between TMACA-NIP and Cu 2+ , which destroys the equilibrium between NIP and copper (II) ions and releases the fluorescence probe of TMACA-NIP. This three-component competing system of NIP/Cu 2+ /GSH can be used to detect GSH simply and rapidly. - Highlights: ► A novel fluorescence probe was developed to detect GSH that operates in aqueous solution. ► TMACA-NIP was synthesized and employed as “read-out” units of NIP/Cu 2+ /GSH. ► NIP-based probe shows high selectivity over other sulfhydryl compounds.

Human glutathione S-transferase-mediated glutathione conjugation of curcumin and efflux of these conjugates in caco-2 cells

NARCIS (Netherlands)

Usta, M.; Wortelboer, H.M.; Vervoort, J.; Boersma, M.G.; Rietjens, I.M.C.M.; Bladeren, P.J. van; Cnubben, N.H.P.

2007-01-01

Curcumin, an α,β-unsaturated carbonyl compound, reacts with glutathione, leading to the formation of two monoglutathionyl curcumin conjugates. In the present study, the structures of both glutathione conjugates of curcumin were identified by LC-MS and one- and two-dimensional 1H NMR analysis, and

Effects of reduced glutathione on acrosin activity in frozen-thawed boar spermatozoa.

Science.gov (United States)

Estrada, Efrén; Rodríguez-Gil, Joan E; Rivera Del Álamo, Maria M; Peña, Alejandro; Yeste, Marc

2017-02-01

In pigs, acrosin activity in extended semen is correlated with reproductive performance and has recently been identified as a freezability marker. Reduced glutathione (GSH) is known to decrease sperm cryodamage and increase the reproductive performance of frozen-thawed boar spermatozoa. However, the effects of GSH on the acrosin activity of good and poor freezability ejaculates (GFE and PFE, respectively) is yet to be examined. The present study investigated how supplementing cryopreservation media with GSH affected acrosin activity in GFE and PFE, as well as the relationship between acrosin activity and reproductive performance in frozen-thawed boar spermatozoa. In addition, we examined whether the increase in fertility rates and litter sizes observed after the addition of 2mM GSH to cryopreservation extenders was related to acrosin activity. Supplementing freezing media with 2mM GSH partially counteracted the cryopreservation-related decrease in acrosin activity in GFE but not PFE. Acrosin activity was found to be significantly correlated with in vivo reproductive performance of frozen-thawed boar semen. In conclusion, the effects of adding GSH to freezing extenders on the acrosin activity of frozen-thawed boar spermatozoa rely on the intrinsic freezability of the ejaculate. Furthermore, the maintenance of proper acrosin activity could contribute to the increase in reproductive performance mediated by GSH.

Aggravation of brain infarction through an increase in acrolein production and a decrease in glutathione with aging.

Science.gov (United States)

Uemura, Takeshi; Watanabe, Kenta; Ishibashi, Misaki; Saiki, Ryotaro; Kuni, Kyoshiro; Nishimura, Kazuhiro; Toida, Toshihiko; Kashiwagi, Keiko; Igarashi, Kazuei

2016-04-29

We previously reported that tissue damage during brain infarction was mainly caused by inactivation of proteins by acrolein. This time, it was tested why brain infarction increases in parallel with aging. A mouse model of photochemically induced thrombosis (PIT) was studied using 2, 6, and 12 month-old female C57BL/6 mice. The size of brain infarction in the mouse PIT model increased with aging. The volume of brain infarction in 12 month-old mice was approximately 2-fold larger than that in 2 month-old mice. The larger brain infarction in 12 month-old mice was due to an increase in acrolein based on an increase in the activity of spermine oxidase, together with a decrease in glutathione (GSH), a major acrolein-detoxifying compound in cells, based on the decrease in one of the subunits of glutathione biosynthesizing enzymes, γ-glutamylcysteine ligase modifier subunit, with aging. The results indicate that aggravation of brain infarction with aging was mainly due to the increase in acrolein production and the decrease in GSH in brain. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluating Superoxide Dismutase (SOD, Glutathione (GSH, Malondialdehyde (MDA and the Histological Changes of the Lung Tissue after γ-Irradiation in Rats

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Abolhasan Rezaeyan

2016-09-01

Full Text Available Background & Objective: The lung is a radiosensitive organ and its damage is a dose-limiting factor in radiotherapy. Different side effects such as pneumonia and lung fibrosis are found in patients with thorax irradiation. The objective of the present study is to evaluate the effects of γ-irradiation on acute and chronic injuries of lung tissue in rats. Materials & Methods: 32 rats were divided into two groups. Control group consisted of 14 rats that underwent shame irradiation. In radiation group, 18 rats underwent γ-irradiation. The rats were exposed to γ-irradiation 18 Gy using a single fraction cobalt-60 unit. Eight rats in each group were sacrificed 24 hours after radiotherapy for determining Superoxide Dismutase (SOD, Glutathione (GSH, Malondialdehyde (MDA, and histopathological evaluations. Remained animals were sacrificed eight weeks after radiotherapy for histopathological evaluation. Results: Compared to control group, the level of SOD and GSH significantly decreased and MDA level significantly increased in radiation group 24 hours following irradiation, (p=0.001, p<0.001, p=0.001 respectively. Early histopathological results after 24 hours showed that radiation increases neutrophil, macrophage, and inflammation incidence compared to control group (p<0.05. Late histopathological evaluation after eight weeks revealed significant increase in factors including mast cells, pulmonary edema, vascular thickness, vascular damage, and also inflammation and fibrosis incidence in case group compared to radiation group  (p<0.05. Conclusion: Localized chest radiation with dose of 18 Gy induces changes in oxidative stress indices and histopathological lung tissue damage in short and long term.

The thiol compounds glutathione and homoglutathione differentially affect cell development in alfalfa (Medicago sativa L.).

Science.gov (United States)

Pasternak, Taras; Asard, Han; Potters, Geert; Jansen, Marcel A K

2014-01-01

Glutathione (GSH) is an important scavenger of Reactive Oxygen Species (ROS), precursor of metal chelating phytochelatins, xenobiotic defence compound and regulator of cell proliferation. Homoglutathione (hGSH) is a GSH homologue that is present in several taxa in the family of Fabaceae. It is thought that hGSH performs many of the stress-defence roles typically ascribed to GSH, yet little is known about the potential involvement of hGSH in controlling cell proliferation. Here we show that hGSH/GSH ratios vary across organs and cells and that these changes in hGSH/GSH ratio occur during dedifferentiation and/or cell cycle activation events. The use of a GSH/hGSH biosynthesis inhibitor resulted in impaired cytokinesis in isolated protoplasts, showing the critical importance of these thiol-compounds for cell division. However, exposure of isolated protoplasts to exogenous GSH accelerated cytokinesis, while exogenous hGSH was found to inhibit the same process. We conclude that GSH and hGSH have distinct functional roles in cell cycle regulation in Medicago sativa L. GSH is associated with meristemic cells, and promotes cell cycle activation and induction of somatic embryogenesis, while hGSH is associated with differentiated cells and embryo proliferation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Randomized, single blind, controlled trial of inhaled glutathione vs placebo in patients with cystic fibrosis.

Science.gov (United States)

Calabrese, C; Tosco, A; Abete, P; Carnovale, V; Basile, C; Magliocca, A; Quattrucci, S; De Sanctis, S; Alatri, F; Mazzarella, G; De Pietro, L; Turino, C; Melillo, E; Buonpensiero, P; Di Pasqua, A; Raia, V

2015-03-01

In cystic fibrosis (CF) the defective CF transmembrane conductance regulator protein may be responsible for the impaired transport of glutathione (GSH), the first line defense of the lung against oxidative stress. The aim of this single-blind, randomized, placebo-controlled trial was to evaluate the effect of inhaled GSH in patients with CF. 54 adult and 51 pediatric patients were randomized to receive inhaled GSH or placebo twice daily for 12 months. Twelve month treatment with inhaled GSH did not achieve our predetermined primary outcome measure of 15% improvement in FEV1%. Only in patients with moderate lung disease, 3, 6 and 9 months therapy with GSH resulted in a statistically significant increase of FEV1 values from the baseline. Moreover GSH therapy improved 6-minute walking test in pediatric population. GSH was well tolerated by all patients. Inhaled GSH has slight positive effects in CF patients with moderate lung disease warranting further study. ClinicalTrials.gov; No.: NCT01450267; URL: www.clinicaltrialsgov. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

The Incomplete Glutathione Puzzle: Just Guessing at Numbers and Figures?

Science.gov (United States)

Deponte, Marcel

2017-11-20

Glutathione metabolism is comparable to a jigsaw puzzle with too many pieces. It is supposed to comprise (i) the reduction of disulfides, hydroperoxides, sulfenic acids, and nitrosothiols, (ii) the detoxification of aldehydes, xenobiotics, and heavy metals, and (iii) the synthesis of eicosanoids, steroids, and iron-sulfur clusters. In addition, glutathione affects oxidative protein folding and redox signaling. Here, I try to provide an overview on the relevance of glutathione-dependent pathways with an emphasis on quantitative data. Recent Advances: Intracellular redox measurements reveal that the cytosol, the nucleus, and mitochondria contain very little glutathione disulfide and that oxidative challenges are rapidly counterbalanced. Genetic approaches suggest that iron metabolism is the centerpiece of the glutathione puzzle in yeast. Furthermore, recent biochemical studies provide novel insights on glutathione transport processes and uncoupling mechanisms. Which parts of the glutathione puzzle are most relevant? Does this explain the high intracellular concentrations of reduced glutathione? How can iron-sulfur cluster biogenesis, oxidative protein folding, or redox signaling occur at high glutathione concentrations? Answers to these questions not only seem to depend on the organism, cell type, and subcellular compartment but also on different ideologies among researchers. A rational approach to compare the relevance of glutathione-dependent pathways is to combine genetic and quantitative kinetic data. However, there are still many missing pieces and too little is known about the compartment-specific repertoire and concentration of numerous metabolites, substrates, enzymes, and transporters as well as rate constants and enzyme kinetic patterns. Gathering this information might require the development of novel tools but is crucial to address potential kinetic competitions and to decipher uncoupling mechanisms to solve the glutathione puzzle. Antioxid. Redox Signal

Cytoplasmic glutathione redox status determines survival upon exposure to the thiol-oxidant 4,4'-dipyridyl disulfide

DEFF Research Database (Denmark)

López-Mirabal, H Reynaldo; Thorsen, Michael; Kielland-Brandt, Morten C

2007-01-01

Dipyridyl disulfide (DPS) is a highly reactive thiol oxidant that functions as electron acceptor in thiol-disulfide exchange reactions. DPS is very toxic to yeasts, impairing growth at low micromolar concentrations. The genes TRX2 (thioredoxin), SOD1 (superoxide dismutase), GSH1 (gamma-glutamyl-c......Dipyridyl disulfide (DPS) is a highly reactive thiol oxidant that functions as electron acceptor in thiol-disulfide exchange reactions. DPS is very toxic to yeasts, impairing growth at low micromolar concentrations. The genes TRX2 (thioredoxin), SOD1 (superoxide dismutase), GSH1 (gamma...... antioxidant pools of glutathione (GSH) and thioredoxin are required for resistance to DPS. We found that DPS-sensitive mutants display increases in the disulfide form of GSH (GSSG) during DPS exposure that roughly correlate with their more oxidizing GSH redox potential in the cytosol and their degree of DPS...

Epalrestat increases intracellular glutathione levels in Schwann cells through transcription regulation

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Keisuke Sato

2014-01-01

Full Text Available Epalrestat (EPS, approved in Japan, is the only aldose reductase inhibitor that is currently available for the treatment of diabetic neuropathy. Here we report that EPS at near-plasma concentration increases the intracellular levels of glutathione (GSH, which is important for protection against oxidative injury, through transcription regulation. Treatment of Schwann cells with EPS caused a dramatic increase in intracellular GSH levels. EPS increased the mRNA levels of γ-glutamylcysteine synthetase (γ-GCS, the enzyme catalyzing the first and rate-limiting step in de novo GSH synthesis. Nuclear factor erythroid 2-related factor 2 (Nrf2 is a key transcription factor that plays a central role in regulating the expression of γ-GCS. ELISA revealed that EPS increased nuclear Nrf2 levels. Knockdown of Nrf2 by siRNA suppressed the EPS-induced GSH biosynthesis. Furthermore, pretreatment with EPS reduced the cytotoxicity induced by H2O2, tert-butylhydroperoxide, 2,2'-azobis (2-amidinopropane dihydrochloride, and menadione, indicating that EPS plays a role in protecting against oxidative stress. This is the first study to show that EPS induces GSH biosynthesis via the activation of Nrf2. We suggest that EPS has new beneficial properties that may prevent the development and progression of disorders caused by oxidative stress.

The effects of cellular glutathione elevation on the oxygen enhancement ratio

International Nuclear Information System (INIS)

Mitchell, J.B.; Russo, A.

1984-01-01

It has recently been demonstrated for Chinese hamster and human A549 cells that depletion of cellular glutathione (GSH) by buthionine sulfoximine sensitizes both aerated and hypoxic cells to X-rays. While the extent of sensitization was minimal for both conditions, there was no overall reduction in the oxygen enhancement ratio (OER). The authors have investigated the effect of cellular GSH elevation on the OER by treating cells for 2 hours with 10 mM L-2-oxothiazolidine-4-carboxylate (OTZ) or face 24 hours with 0.06 mM cobalt chloride (CoCl/sub 2/) in complete medium. These treatments resulted in cellular concentrations of GSH to approximately 150-250% for OTZ and 150-300% for CoCl/sub 2/ when compared to controls. X-ray survival curves were determined following these treatments for aerated and hypoxic conditions. Hypoxia was induced by metabolic utilization of oxygen at high cell densities (10/sup 8//ml) in glass syringes. For both methods of GSH elevation, there was no protection observed for either aerated or hypoxic cells and consequently no change in the OER when compared to controls. These data are discussed in the context of the radical-scavenging hypothesis involving chemical repair following X-rays of compounds such as GSH

Alleviation of isoproturon toxicity to wheat by exogenous application of glutathione.

Science.gov (United States)

Nemat Alla, Mamdouh M; Hassan, Nemat M

2014-06-01

Treatment with the recommended field dose of isoproturon to 7-d-old wheat seedlings significantly decreased shoot height, fresh and dry weights during the subsequent 15days. Meanwhile contents of carotenoids, chlorophylls and anthocyanin as well as activities of δ-aminolevulinate dehydratase (ALA-D), phenylalanine ammonia lyase (PAL) and tyrosine ammonia lyase (TAL) were significantly inhibited. On the other hand, the herbicide significantly increased malondialdehyde (MDA), a naturally occurring product of lipid peroxidation and H2O2, while it significantly decreased the contents of glutathione (GSH) and ascorbic acid (AsA) and reduced the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX). These findings indicate an induction of a stress status in wheat seedlings following isoproturon treatment. However, exogenous GSH appeared to limit the toxic effects of isoproturon and seemed to overcome this stress status. Most likely, contents of pigment and activities of enzymes were raised to approximate control levels. Moreover, antioxidants were elevated and the oxidative stress indices seemed to be alleviated by GSH application. These results indicate that exogenous GSH enhances enzymatic and nonenzymatic antioxidants to alleviate the effects of isoproturon. Copyright © 2014 Elsevier Inc. All rights reserved.

Short communication: Protection of lyophilized milk starter Lactobacillus casei Zhang by glutathione.

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Zhang, Juan; Liu, Qian; Chen, Wei; Du, Guocheng; Chen, Jian

2016-03-01

Lyophilization is considered an effective way to preserve the activity of milk starters, such as lactic acid bacteria, in which proper protective agents play key roles. In this study, Lactobacillus casei Zhang, a probiotic bacterium applied as a milk starter in China, was used to investigate the effects of various cryoprotectants according to cell survival rate and physiological characteristics. The result showed a significant survival improvement to 86.6% when glutathione (GSH) was added as an ideal cryoprotectant. Further study revealed that GSH plays a key role on maintaining higher unsaturation ratio of cell membrane and shorter chain length of saturated fatty acids. In this case, the intact cell structure can be obtained. These findings will contribute not only to deepen the understanding of cells during lyophilization but also to improve the industrial performance of certain milk starters such as L. casei Zhang by application of GSH as cryoprotectant. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

L-cysteine efflux in erythrocytes as a function of human age: correlation with reduced glutathione and total anti-oxidant potential.

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Kumar, Prabhanshu; Maurya, Pawan Kumar

2013-06-01

Thiol compounds such as cysteine (Cys) and reduced glutathione (GSH) play an important role in human aging and age-related diseases. In erythrocytes, GSH is synthesized by glutamic acid, cysteine, and glycine, but the rate of GSH synthesis is determined only by the availability of L-cysteine. Cysteine supplementation has been shown to ameliorate several parameters that are known to degenerate during human aging. We have studied L-cysteine efflux in vitro in human erythrocytes as a function of age by suspending cells in solution containing 10 mM L-cysteine for uptake; later cells were re-suspended in phosphate-buffered saline (PBS)-glucose to allow efflux. Change in the free sulfhydryl (-SH) concentration was then measured to calculate the rate of efflux. The GSH/oxidized glutathione (GSSG) ratio was taken as a control to study the oxidation/reduction state of the erythrocyte. The total anti-oxidant potential of plasma was measured in terms of ferric reducing ability of plasma (FRAP) values. We have shown a significant (pL-cysteine in erythrocytes during human aging, and the GSH/GSSG ratio decreases as a function of human age. The decline in L-cysteine efflux during aging correlates with the decrease in GSH and the FRAP value. This finding may help to explain the shift in the redox status and low GSH concentration that might determine the rate of L-cysteine efflux observed in erythrocytes and an important factor in the development of oxidative stress in erythrocytes during aging.

The influence of single application of paracetamol and/or N-acetylcysteine on rats in subchronic exposition to trichloroethylene vapours. II. Effect on hepatic glutathione level

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Danuta Plewka

2012-09-01

Full Text Available Background: Feature of modern existing hazards both environmental and occupational is cumulative exposure often leading to unexpected response of the organism resulting, among other things, in interactions with cytochrome P450 system involved in biotransformation of trichloroethylene and paracetamol. Hepatotoxity of paracetamol is closely connected with hepatic glutathione level. „In therapy of acute paracetamol poisoning application of N-acetylcysteine as a factor, which protects GSH level in cells, is recommended.” Materials and method: Tests were performed on rats which were treated with trichloroethylene, paracetamol and/or N-acetylcysteine. In rat liver total level of glutathione was determined i.e. reduced and oxidized form. Results: Paracetamol just after completion of the exposure affected the glutathione level. Trichloroethylene throughout the period of observation stimulated growth of glutathione level in liver. N-acetylcysteine didn’t have any influence on the level of investigated tripeptyde. Conclusions: N-acetylcysteine removes negative effect of paracetamol especially when it’s applied with 2-hour delay. After exposure for trichloethylene immediate application of N-acetylcysteine caused noticeable lowering of glutathione level. Cumulative exposure for three xenobiotics had positive influence for glutathione level in rat liver.

Cadmium-Induced Hydrogen Accumulation Is Involved in Cadmium Tolerance in Brassica campestris by Reestablishment of Reduced Glutathione Homeostasis.

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Wu, Qi; Su, Nana; Chen, Qin; Shen, Wenbiao; Shen, Zhenguo; Xia, Yan; Cui, Jin

2015-01-01

Hydrogen gas (H2) was recently proposed as a therapeutic antioxidant and signaling molecule in clinical trials. However, the underlying physiological roles of H2 in plants remain unclear. In the present study, hydrogen-rich water (HRW) was used to characterize the physiological roles of H2 in enhancing the tolerance of Brassica campestris against cadmium (Cd). The results showed that both 50 μM CdCl2 and 50%-saturated HRW induced an increase of endogenous H2 in Brassica campestris seedlings, and HRW alleviated Cd toxicity related to growth inhibition and oxidative damage. Seedlings supplied with HRW exhibited increased root length and reduced lipid peroxidation, similar to plants receiving GSH post-treatment. Additionally, seedlings post-treated with HRW accumulated higher levels of reduced glutathione (GSH) and ascorbic acid (AsA) and showed increased GST and GPX activities in roots. Molecular evidence illustrated that the expression of genes such as GS, GR1 and GR2, which were down-regulated following the addition of Cd, GSH or BSO, could be reversed to varying degrees by the addition of HRW. Based on these results, it could be proposed that H2 might be an important regulator for enhancing the tolerance of Brassica campestris seedlings against Cd, mainly by governing reduced glutathione homeostasis.

Analysis of MTHFR, CBS, Glutathione, Taurine, and Hydrogen Sulfide Levels in Retinas of Hyperhomocysteinemic Mice.

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Cui, Xuezhi; Navneet, Soumya; Wang, Jing; Roon, Penny; Chen, Wei; Xian, Ming; Smith, Sylvia B

2017-04-01

Hyperhomocysteinemia (Hhcy) is implicated in certain retinal neurovascular diseases, although whether it is causative remains uncertain. In isolated ganglion cells (GCs), mild Hhcy induces profound death, whereas retinal phenotypes in Hhcy mice caused by mutations in remethylation (methylene tetrahydrofolatereductase [Mthfr+/-]) or transsulfuration pathways (cystathionine β-synthase [Cbs+/-]) demonstrate mild GC loss and mild vasculopathy. The current work investigated compensation in vivo of one pathway for the other, and, because the transsulfuration pathway yields cysteine necessary for formation of glutathione (GSH), taurine, and hydrogen sulfide (H2S), they were analyzed also. Retinas isolated from wild-type (WT), Mthfr+/-, and Cbs+/- mice (12 and 22 weeks) were analyzed for methylene tetrahydrofolate reductase (MTHFR), cystathionine-β-synthase (CBS), and cystathionase (CTH) RNA/protein levels. Retinas were evaluated for levels of reduced:oxidized GSH (GSH:GSSG), Slc7a11 (xCT), taurine, taurine transporter (TAUT), and H2S. Aside from decreased CBS RNA/protein levels in Cbs+/- retinas, there were minimal alterations in remethylation/transsulfuration pathways in the two mutant mice strains. Glutathione and taurine levels in Mthfr+/- and Cbs+/- retinas were similar to WT, which may be due to robust levels of xCT and TAUT in mutant retinas. Interestingly, levels of H2S were markedly increased in retinas of Mthfr+/- and Cbs+/- mice compared with WT. Ganglion cell loss and vasculopathy observed in Mthfr+/- and Cbs+/- mouse retinas may be milder than expected, not because of compensatory increases of enzymes in remethylation/transsulfuration pathways, but because downstream transsulfuration pathway products GSH, taurine, and H2S are maintained at robust levels. Elevation of H2S is particularly intriguing owing to neuroprotective properties reported for this gasotransmitter.

Glutathione-capped CdTe nanocrystals as probe for the determination of fenbendazole

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Li, Qin; Tan, Xuanping; Li, Jin; Pan, Li; Liu, Xiaorong

2015-04-01

Water-soluble glutathione (GSH)-capped CdTe quantum dots (QDs) were synthesized. In pH 7.1 PBS buffer solution, the interaction between GSH-capped CdTe QDs and fenbendazole (FBZ) was investigated by spectroscopic methods, including fluorescence spectroscopy, ultraviolet-visible absorption spectroscopy, and resonance Rayleigh scattering (RRS) spectroscopy. In GSH-capped CdTe QDs solution, the addition of FBZ results in the fluorescence quenching and RRS enhancement of GSH-capped CdTe QDs. And the quenching intensity (enhanced RRS intensity) was proportional to the concentration of FBZ in a certain range. Investigation of the interaction mechanism, proved that the fluorescence quenching and RRS enhancement of GSH-capped CdTe QDs by FBZ is the result of electrostatic attraction. Based on the quenching of fluorescence (enhancement of RRS) of GSH-capped CdTe QDs by FBZ, a novel, simple, rapid and specific method for FBZ determination was proposed. The detection limit for FBZ was 42 ng mL-1 (3.4 ng mL-1) and the quantitative determination range was 0-2.8 μg mL-1 with a correlation of 0.9985 (0.9979). The method has been applied to detect FBZ in real simples and with satisfactory results.

Pathological and biochemical changes in rat eyes exposed to gamma irradiation and benzo(A) pyrene and the protective role of glutathione and oltipraze

International Nuclear Information System (INIS)

Abd Elmaguid, A.; Naguib, N.I.; Saad, T.M.M.

2007-01-01

This study aims to evaluate the effect of exposure to carcinogenic compounds as benzo(a)pyrene in combination with other risk factor which is gamma irradiation on different eye tissues. The study was also conducted to evaluate the protective role of antioxidants such as glutathione and oltipraze before and during exposure to the risk factors. The first group of rats was kept as normal untreated control group. The second group was treated with oltipraze and glutathione for 14 days (positive control group). The third group was injected (i.p) with benzo(a)pyrene in three successive doses parallel with exposure to whole body gamma irradiation of 6 Gy divided in three successive doses ( 2 Gy/ day). The fourth group was treated with oltipraze and glutathione for 14 days then injected (i.p) with benzo(a)pyrene in the last 3 days of treatment in three successive doses parallel with exposure to the same whole body gamma irradiation as third group (6 Gy). Rat eyes were examined clinically every week. For histopathological and biochemical examinations, all groups were sacrificed at 1 month and 2 months after irradiation exposure and the eye tissues were examined by light microscope. The biochemical parameters such as lipid peroxides, SOD, GSH, GSH reductase and GSH peroxidase were estimated in blood and lens. Soluble and insoluble proteins were measured in lens only.The results showed that i.p injection of rats with benzo(a)pyrene and exposure to gamma irradiation caused alterations in eyes of rats clinically, histologically and biochemically. Animals that received glutathione and oltipraze and subjected to benzo(a)pyrene and radiation showed noticeable amelioration in the assayed parameters indicating their protective role as promising agents

21 CFR 864.7375 - Glutathione reductase assay.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Glutathione reductase assay. 864.7375 Section 864.7375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7375 Glutathione...

Molecularly imprinted solid-phase extraction of glutathione from urine samples

International Nuclear Information System (INIS)

Song, Renyuan; Hu, Xiaoling; Guan, Ping; Li, Ji; Zhao, Na; Wang, Qiaoli

2014-01-01

Molecularly imprinted polymer (MIP) particles for glutathione were synthesized through iniferter-controlled living radical precipitation polymerization (IRPP) under ultraviolet radiation at ambient temperature. Static adsorption, solid-phase extraction, and high-performance liquid chromatography were carried out to evaluate the adsorption properties and selective recognition characteristics of the polymers for glutathione and its structural analogs. The obtained IRPP-MIP particles exhibited a regularly spherical shape, rapid binding kinetics, high imprinting factor, and high selectivity compared with the MIP particles prepared using traditional free-radical precipitation polymerization. The selective separation and enrichment of glutathione from the mixture of glycyl-glycine and glutathione disulfide could be achieved on the IRPP-MIP cartridge. The recoveries of glutathione, glycyl-glycine, and glutathione disulfide were 95.6% ± 3.65%, 29.5% ± 1.26%, and 49.9% ± 1.71%, respectively. The detection limit (S/N = 3) of glutathione was 0.5 mg·L −1 . The relative standard deviations (RSDs) for 10 replicate detections of 50 mg·L −1 of glutathione were 5.76%, and the linear range of the calibration curve was 0.5 mg·L −1 to 200 mg·L −1 under optimized conditions. The proposed approach was successfully applied to determine glutathione in spiked human urine samples with recoveries of 90.24% to 96.20% and RSDs of 0.48% to 5.67%. - Highlights: • Imprinted polymer particles were prepared by IRPP at ambient temperature. • High imprinting factor, high selectivity, and rapid binding kinetics were achieved. • Selective solid-phase extraction of glutathione from human urine samples

Impact of uranium (U) on the cellular glutathione pool and resultant consequences for the redox status of U.

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Viehweger, Katrin; Geipel, Gerhard; Bernhard, Gert

2011-12-01

Uranium (U) as a redox-active heavy metal can cause various redox imbalances in plant cells. Measurements of the cellular glutathione/glutathione disulfide (GSH/GSSG) by HPLC after cellular U contact revealed an interference with this essential redox couple. The GSH content remained unaffected by 10 μM U whereas the GSSG level immediately increased. In contrast, higher U concentrations (50 μM) drastically raised both forms. Using the Nernst equation, it was possible to calculate the half-cell reduction potential of 2GSH/GSSG. In case of lower U contents the cellular redox environment shifted towards more oxidizing conditions whereas the opposite effect was obtained by higher U contents. This indicates that U contact causes a consumption of reduced redox equivalents. Artificial depletion of GSH by chlorodinitrobenzene and measuring the cellular reducing capacity by tetrazolium salt reduction underlined the strong requirement of reduced redox equivalents. An additional element of cellular U detoxification mechanisms is the complex formation between the heavy metal and carboxylic functionalities of GSH. Because two GSH molecules catalyze electron transfers each with one electron forming a dimer (GSSG) two UO(2) (2+) are reduced to each UO(2) (+) by unbound redox sensitive sulfhydryl moieties. UO(2) (+) subsequently disproportionates to UO(2) (2+) and U(4+). This explains that in vitro experiments revealed a reduction to U(IV) of only around 33% of initial U(VI). Cellular U(IV) was transiently detected with the highest level after 2 h of U contact. Hence, it can be proposed that these reducing processes are an important element of defense reactions induced by this heavy metal.

Effect of glutathione on phytochelatin synthesis in tomato cells. [Lycopersicon esculentum

Energy Technology Data Exchange (ETDEWEB)

Mendum, M.L.; Gupta, S.C.; Goldsbrough, P.B. (Purdue Univ., West Lafayette, IN (USA))

1990-06-01

Growth of cell suspension cultures of tomato, Lycopersicon esculentum Mill. cv VFNT-Cherry, in the presence of cadmium is inhibited by buthionine sulfoximine, an inhibitor of glutathione synthesis. Cell growth and phytochelatin synthesis are restored to cells treated with buthionine sulfoximine by the addition of glutathione to the medium. Glutathione stimulates the accumulation of phytochelatins in cadmium treated cells, indicating that availability of glutathione can limit synthesis of these peptides. Exogenous glutathione causes a disproportionate increase in the level of smaller phytochelatins, notably ({gamma}-Glu-Cys){sub 2}-Gly. In the presence of buthionine sulfoximine and glutathione, phytochelatins that are produced upon exposure to cadmium incorporate little ({sup 35}S)cysteine, indicating that these peptides are probably not synthesized by sequential addition of cysteine and glutamate to glutathione.

Mechanism-based biomarker gene sets for glutathione depletion-related hepatotoxicity in rats

International Nuclear Information System (INIS)

Gao Weihua; Mizukawa, Yumiko; Nakatsu, Noriyuki; Minowa, Yosuke; Yamada, Hiroshi; Ohno, Yasuo; Urushidani, Tetsuro

2010-01-01

Chemical-induced glutathione depletion is thought to be caused by two types of toxicological mechanisms: PHO-type glutathione depletion [glutathione conjugated with chemicals such as phorone (PHO) or diethyl maleate (DEM)], and BSO-type glutathione depletion [i.e., glutathione synthesis inhibited by chemicals such as L-buthionine-sulfoximine (BSO)]. In order to identify mechanism-based biomarker gene sets for glutathione depletion in rat liver, male SD rats were treated with various chemicals including PHO (40, 120 and 400 mg/kg), DEM (80, 240 and 800 mg/kg), BSO (150, 450 and 1500 mg/kg), and bromobenzene (BBZ, 10, 100 and 300 mg/kg). Liver samples were taken 3, 6, 9 and 24 h after administration and examined for hepatic glutathione content, physiological and pathological changes, and gene expression changes using Affymetrix GeneChip Arrays. To identify differentially expressed probe sets in response to glutathione depletion, we focused on the following two courses of events for the two types of mechanisms of glutathione depletion: a) gene expression changes occurring simultaneously in response to glutathione depletion, and b) gene expression changes after glutathione was depleted. The gene expression profiles of the identified probe sets for the two types of glutathione depletion differed markedly at times during and after glutathione depletion, whereas Srxn1 was markedly increased for both types as glutathione was depleted, suggesting that Srxn1 is a key molecule in oxidative stress related to glutathione. The extracted probe sets were refined and verified using various compounds including 13 additional positive or negative compounds, and they established two useful marker sets. One contained three probe sets (Akr7a3, Trib3 and Gstp1) that could detect conjugation-type glutathione depletors any time within 24 h after dosing, and the other contained 14 probe sets that could detect glutathione depletors by any mechanism. These two sets, with appropriate scoring

Rational design of reversible fluorescent probes for live-cell imaging and quantification of fast glutathione dynamics

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Umezawa, Keitaro; Yoshida, Masafumi; Kamiya, Mako; Yamasoba, Tatsuya; Urano, Yasuteru

2017-03-01

Alterations in glutathione (GSH) homeostasis are associated with a variety of diseases and cellular functions, and therefore, real-time live-cell imaging and quantification of GSH dynamics are important for understanding pathophysiological processes. However, existing fluorescent probes are unsuitable for these purposes due to their irreversible fluorogenic mechanisms or slow reaction rates. In this work, we have successfully overcome these problems by establishing a design strategy inspired by Mayr's work on nucleophilic reaction kinetics. The synthesized probes exhibit concentration-dependent, reversible and rapid absorption/fluorescence changes (t1/2 = 620 ms at [GSH] = 1 mM), as well as appropriate Kd values (1-10 mM: within the range of intracellular GSH concentrations). We also developed FRET-based ratiometric probes, and demonstrated that they are useful for quantifying GSH concentration in various cell types and also for real-time live-cell imaging of GSH dynamics with temporal resolution of seconds.

One-electron oxidation of diclofenac by human cytochrome P450s as a potential bioactivation mechanism for formation of 2'-(glutathion-S-yl)-deschloro-diclofenac.

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Boerma, Jan Simon; Vermeulen, Nico P E; Commandeur, Jan N M

2014-01-25

Reactive metabolites have been suggested to play a role in the idiosyncratic hepatotoxicity observed with diclofenac (DF). By structural identification of the GSH conjugates formed after P450-catalyzed bioactivation of DF, it was shown that three types of reactive intermediates were formed: p-benzoquinone imines, o-imine methide and arene-oxide. Recently, detection of 2'-(glutathion-S-yl)-deschloro-diclofenac (DDF-SG), resulting from chlorine substitution, suggested the existence of a fourth type of P450-dependent reactive intermediate whose inactivation by GSH is completely dependent on presence of glutathione S-transferase. In this study, fourteen recombinant cytochrome P450s and three flavin-containing monooxygenases were tested for their ability to produce oxidative DF metabolites and their corresponding GSH conjugates. Concerning the hydroxymetabolites and their GSH conjugates, results were consistent with previous studies. Unexpectedly, all tested recombinant P450s were able to form DDF-SG to almost similar extent. DDF-SG formation was found to be partially independent of NADPH and even occurred by heat-inactivated P450. However, product formation was fully dependent on both GSH and glutathione-S-transferase P1-1. DDF-SG formation was also observed in reactions with horseradish peroxidase in absence of hydrogen peroxide. Because DDF-SG was not formed by free iron, it appears that DF can be bioactivated by iron in hemeproteins. This was confirmed by DDF-SG formation by other hemeproteins such as hemoglobin. As a mechanism, we propose that DF is subject to heme-dependent one-electron oxidation. The resulting nitrogen radical cation, which might activate the chlorines of DF, then undergoes a GST-catalyzed nucleophilic aromatic substitution reaction in which the chlorine atom of the DF moiety is replaced by GSH. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Exogenous Glutathione Enhances Mercury Tolerance by Inhibiting Mercury Entry into Plant Cells

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Kim, Yeon-Ok; Bae, Hyeun-Jong; Cho, Eunjin; Kang, Hunseung

2017-01-01

Despite the increasing understanding of the crucial roles of glutathione (GSH) in cellular defense against heavy metal stress as well as oxidative stress, little is known about the functional role of exogenous GSH in mercury (Hg) tolerance in plants. Here, we provide compelling evidence that GSH contributes to Hg tolerance in diverse plants. Exogenous GSH did not mitigate the toxicity of cadmium (Cd), copper (Cu), or zinc (Zn), whereas application of exogenous GSH significantly promoted Hg tolerance during seed germination and seedling growth of Arabidopsis thaliana, tobacco, and pepper. By contrast, addition of buthionine sulfoximine, an inhibitor of GSH biosynthesis, severely retarded seed germination and seedling growth of the plants in the presence of Hg. The effect of exogenous GSH on Hg specific tolerance was also evident in the presence of other heavy metals, such as Cd, Cu, and Zn, together with Hg. GSH treatment significantly decreased H2O2 and O2- levels and lipid peroxidation, but increased chlorophyll content in the presence of Hg. Importantly, GSH treatment resulted in significantly less accumulation of Hg in Arabidopsis plants, and thin layer chromatography and nuclear magnetic resonance analysis revealed that GSH had much stronger binding affinity to Hg than to Cd, Cu, or Zn, suggesting that tight binding of GSH to Hg impedes Hg uptake, leading to low Hg accumulation in plant cells. Collectively, the present findings reveal that GSH is a potent molecule capable of conferring Hg tolerance by inhibiting Hg accumulation in plants. PMID:28507557

Exogenous Glutathione Enhances Mercury Tolerance by Inhibiting Mercury Entry into Plant Cells

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Yeon-Ok Kim

2017-05-01

Full Text Available Despite the increasing understanding of the crucial roles of glutathione (GSH in cellular defense against heavy metal stress as well as oxidative stress, little is known about the functional role of exogenous GSH in mercury (Hg tolerance in plants. Here, we provide compelling evidence that GSH contributes to Hg tolerance in diverse plants. Exogenous GSH did not mitigate the toxicity of cadmium (Cd, copper (Cu, or zinc (Zn, whereas application of exogenous GSH significantly promoted Hg tolerance during seed germination and seedling growth of Arabidopsis thaliana, tobacco, and pepper. By contrast, addition of buthionine sulfoximine, an inhibitor of GSH biosynthesis, severely retarded seed germination and seedling growth of the plants in the presence of Hg. The effect of exogenous GSH on Hg specific tolerance was also evident in the presence of other heavy metals, such as Cd, Cu, and Zn, together with Hg. GSH treatment significantly decreased H2O2 and O2- levels and lipid peroxidation, but increased chlorophyll content in the presence of Hg. Importantly, GSH treatment resulted in significantly less accumulation of Hg in Arabidopsis plants, and thin layer chromatography and nuclear magnetic resonance analysis revealed that GSH had much stronger binding affinity to Hg than to Cd, Cu, or Zn, suggesting that tight binding of GSH to Hg impedes Hg uptake, leading to low Hg accumulation in plant cells. Collectively, the present findings reveal that GSH is a potent molecule capable of conferring Hg tolerance by inhibiting Hg accumulation in plants.

Mechanisms of radiosensitization and protection studied with glutathione-deficient human cell lines

International Nuclear Information System (INIS)

Revesz, L.; Edgren, M.

1982-01-01

Glutathione-deficient fibroblasts and lymphoblastoid cells, derived from patients with an inborn error of glutathione synthetase activity, and glutathione-proficient cells, derived from clinically healthy individuals, were used to investigate the importance of glutathione for radiosensitization by misonidazole. With single-strand DNA breaks as an end point, misonidazole as well as oxygen was found to lack any sensitizing effect on cells deficient in glutathione. The post-irradiation repair of single-strand breaks induced by hypoxic irradiation of misonidazole treated cells was found to be a great extent glutathione dependent, like the repair of breaks induced by oxic irradiation. Naturally occurring aminothiols in glutathione-deficient cells appeared to be in efficient as substitutes for glutatione. Artificial aminothiols, such as cysteamine or dithiothreitol, were found to effectively replace glutathione

Glutathione, cell proliferation and differentiation | Ashtiani | African ...

African Journals Online (AJOL)

All organisms require an equivalent source for living. Reduced glutathione is the most abundant thiol containing protein in mammalian cells and organs. Glutathione was discovered by Hopkins in 1924 who published his findings in JBC. It is a three peptide containing glutamic acid, cystein and glycin and is found in reduced ...

A role for glutathione, independent of oxidative stress, in the developmental toxicity of methanol

International Nuclear Information System (INIS)

Siu, Michelle T.; Shapiro, Aaron M.; Wiley, Michael J.; Wells, Peter G.

2013-01-01

Oxidative stress and reactive oxygen species (ROS) have been implicated in the teratogenicity of methanol (MeOH) in rodents, both in vivo and in embryo culture. We explored the ROS hypothesis further in vivo in pregnant C57BL/6J mice. Following maternal treatment with a teratogenic dose of MeOH, 4 g/kg via intraperitoneal (ip) injection on gestational day (GD) 12, there was no increase 6 h later in embryonic ROS formation, measured by 2′,7′-dichlorodihydrofluorescin diacetate (DCFH-DA) fluorescence, despite an increase observed with the positive control ethanol (EtOH), nor was there an increase in embryonic oxidatively damaged DNA, quantified as 8-oxo-2′-deoxyguanosine (8-oxodG) formation. MeOH teratogenicity (primarily ophthalmic anomalies, cleft palate) also was not altered by pre- and post-treatment with varying doses of the free radical spin trapping agent alpha-phenyl-N-tert-butylnitrone (PBN). In contrast, pretreatment with L-buthionine-(S,R)-sulfoximine (BSO), an inhibitor of glutathione (GSH) synthesis, depleted maternal hepatic and embryonic GSH, and enhanced some new anomalies (micrognathia, agnathia, short snout, fused digits, cleft lip, low set ears), but not the most common teratogenic effects of MeOH (ophthalmic anomalies, cleft palate) in this strain. These results suggest that ROS did not contribute to the teratogenic effects of MeOH in this in vivo mouse model, in contrast to results in embryo culture from our laboratory, and that the protective effect of GSH in this model may arise from its role as a cofactor for formaldehyde dehydrogenase in the detoxification of formaldehyde. - Highlights: • In vivo, a free radical scavenger did not block methanol (MeOH) teratogenesis. • MeOH did not increase embryonic reactive oxygen species formation or DNA oxidation. • MeOH teratogenesis was enhanced by glutathione (GSH) depletion. • GSH may protect as the cofactor for formaldehyde dehydrogenase (ADH3). • Formaldehyde may be a ROS

Glutathione regulation-based dual-functional upconversion sensing-platform for acetylcholinesterase activity and cadmium ions.

Science.gov (United States)

Fang, Aijin; Chen, Hongyu; Li, Haitao; Liu, Meiling; Zhang, Youyu; Yao, Shouzhuo

2017-01-15

A dual-functional platform for the sensing of acetylcholinesterase (AChE) activity and cadmium ions (Cd 2+ ) was developed based on the fluorescence resonance energy transfer (FRET) between NaYF 4 :Yb,Er upconversion nanoparticles (UCNPs) and gold nanoparticles (AuNPs) via glutathione regulation. The detection mechanism is based on the fact that AuNPs can quench the fluorescence of UCNPs. AChE catalyzes the hydrolysis of acetylthiocholine (ATC) into thiocholine which reacts with AuNPs by S-Au conjunction and results the aggregation of AuNPs and change in fluorescence of UCNPs. Therefore, the AChE activity can be detected through the changes of the color of solution and fluorescence recovery of UCNPs. However, the presence of glutathione (GSH) can protect AuNPs from aggregation and enlarge the inter-particle distance between AuNPs and UCNPs. When Cd 2+ is added into the stable mixture of AuNPs, GSH and AChE/ATC, Cd 2+ could interact with GSH to form a spherical shaped (GSH) 4 Cd complex, which decreases the free GSH on the surface of AuNPs to weaken the stability of AuNPs and lead to the easily aggregation of them in the system. The aggregated-AuNPs are released from the surface of UCNPs, which results in the fluorescence of UCNPs gradually recovered. Under the optimized conditions, the detection limits of AChE activity and Cd 2+ are estimated to be 0.015mU/mL and 0.2µM, respectively. The small molecules regulated dual-functional platform based on UCNPs/AuNPs is a simple, label-free method and can be applied for the turn-on fluorescence detection of AChE activity in human serum and Cd 2+ in real water samples. The present work demonstrates a general strategy for the design of small molecules regulated multifunctional platform and will be expanded for different areas in the future. Copyright © 2016 Elsevier B.V. All rights reserved.

A role for glutathione, independent of oxidative stress, in the developmental toxicity of methanol

Energy Technology Data Exchange (ETDEWEB)

Siu, Michelle T.; Shapiro, Aaron M. [Division of Biomolecular Sciences, Faculty of Pharmacy, University of Toronto, Toronto, Ontario (Canada); Wiley, Michael J. [Division of Anatomy, Faculty of Medicine, University of Toronto, Toronto, Ontario (Canada); Wells, Peter G., E-mail: pg.wells@utoronto.ca [Division of Biomolecular Sciences, Faculty of Pharmacy, University of Toronto, Toronto, Ontario (Canada); Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, Ontario (Canada)

2013-12-15

Oxidative stress and reactive oxygen species (ROS) have been implicated in the teratogenicity of methanol (MeOH) in rodents, both in vivo and in embryo culture. We explored the ROS hypothesis further in vivo in pregnant C57BL/6J mice. Following maternal treatment with a teratogenic dose of MeOH, 4 g/kg via intraperitoneal (ip) injection on gestational day (GD) 12, there was no increase 6 h later in embryonic ROS formation, measured by 2′,7′-dichlorodihydrofluorescin diacetate (DCFH-DA) fluorescence, despite an increase observed with the positive control ethanol (EtOH), nor was there an increase in embryonic oxidatively damaged DNA, quantified as 8-oxo-2′-deoxyguanosine (8-oxodG) formation. MeOH teratogenicity (primarily ophthalmic anomalies, cleft palate) also was not altered by pre- and post-treatment with varying doses of the free radical spin trapping agent alpha-phenyl-N-tert-butylnitrone (PBN). In contrast, pretreatment with L-buthionine-(S,R)-sulfoximine (BSO), an inhibitor of glutathione (GSH) synthesis, depleted maternal hepatic and embryonic GSH, and enhanced some new anomalies (micrognathia, agnathia, short snout, fused digits, cleft lip, low set ears), but not the most common teratogenic effects of MeOH (ophthalmic anomalies, cleft palate) in this strain. These results suggest that ROS did not contribute to the teratogenic effects of MeOH in this in vivo mouse model, in contrast to results in embryo culture from our laboratory, and that the protective effect of GSH in this model may arise from its role as a cofactor for formaldehyde dehydrogenase in the detoxification of formaldehyde. - Highlights: • In vivo, a free radical scavenger did not block methanol (MeOH) teratogenesis. • MeOH did not increase embryonic reactive oxygen species formation or DNA oxidation. • MeOH teratogenesis was enhanced by glutathione (GSH) depletion. • GSH may protect as the cofactor for formaldehyde dehydrogenase (ADH3). • Formaldehyde may be a ROS

Glutathione Metabolism and Parkinson’s Disease

OpenAIRE

Smeyne, Michelle; Smeyne, Richard Jay

2013-01-01

It has been established that oxidative stress, defined as the condition when the sum of free radicals in a cell exceeds the antioxidant capacity of the cell, contributes to the pathogenesis of Parkinson’s disease. Glutathione is a ubiquitous thiol tripeptide that acts alone, or in concert with enzymes within cells to reduce superoxide radicals, hydroxyl radicals and peroxynitrites. In this review, we examine the synthesis, metabolism and functional interactions of glutathione, and discuss how...

Cyclic voltammetric study of the redox system of glutathione using the disulfide bond reductant tris(2-carboxyethyl)phosphine

Czech Academy of Sciences Publication Activity Database

Kizek, René; Vacek, Jan; Trnková, L.; Jelen, František

2004-01-01

Roč. 63, 1-2 (2004), s. 19-24 ISSN 1567-5394 R&D Projects: GA AV ČR IAA1163201; GA ČR GA203/02/0422 Institutional research plan: CEZ:AV0Z5004920 Keywords : voltammetry * hanging mercury drop electrode (HMDE) * glutathione (GSH, GSSG) Subject RIV: BO - Biophysics Impact factor: 2.261, year: 2004

Effect of Vitamin C on Glutathione Peroxidase Activities in Pregnant ...

African Journals Online (AJOL)

Glutathione peroxidase is one of the most important antioxidant enzymes in humans. We studied the relationship between serum glutathione peroxidase activity and vitamin C ingestion during normal pregnancy in women attending antenatal clinic in the University of Ilorin Teaching Hospital, Ilorin. Glutathione peroxidase ...

Compartment specific importance of glutathione during abiotic and biotic stress

Directory of Open Access Journals (Sweden)

Bernd eZechmann

2014-10-01

Full Text Available The tripeptide thiol glutathione (γ-L-glutamyl-L-cysteinyl-glycine is the most important sulfur containing antioxidant in plants and essential for plant defense against abiotic and biotic stress conditions. It is involved in the detoxification of reactive oxygen species, redox signaling, the modulation of defense gene expression and important for the regulation of enzymatic activities. Even though changes in glutathione contents are well documented in plants and its roles in plant defense are well established, still too little is known about its compartment specific importance during abiotic and biotic stress conditions. Due to technical advances in the visualization of glutathione and the redox state of plants through microscopical methods some progress was made in the last few years in studying the importance of subcellular glutathione contents during stress conditions in plants. This review summarizes the data available on compartment specific importance of glutathione in the protection against abiotic and biotic stress conditions such as high light stress, exposure to cadmium, drought, and pathogen attack (Pseudomonas, Botrytis, Tobacco Mosaic Virus. The data will be discussed in connection with the subcellular accumulation of ROS during these conditions and glutathione synthesis which are both highly compartment specific (e.g. glutathione synthesis takes place in chloroplasts and the cytosol. Thus this review will reveal the compartment specific importance of glutathione during abiotic and biotic stress conditions.

Superoxide radical (O2-) reactivity with respect to glutathione

International Nuclear Information System (INIS)

Sekaki, A.; Gardes-Albert, M.; Ferradini, C.

1984-01-01

Influence of superoxide radicals formed during gamma irradiation of glutathione in aerated aqueous solutions is examined. Solutions are buffered at pH7 and contain sodium formate for capture of H and OH radicals which are transformed in COO - radicals and then O 2 - radicals. G value of glutathione disparition vs glutathione concentration are given with and without enzyme or catalase. Reaction mechanism are interpreted [fr

Binding of Glutathione to Enterovirus Capsids Is Essential for Virion Morphogenesis

Science.gov (United States)

Thibaut, Hendrik Jan; Thys, Bert; Canela, María-Dolores; Aguado, Leire; Wimmer, Eckard; Paul, Aniko; Pérez-Pérez, María-Jesús; van Kuppeveld, Frank J. M.; Neyts, Johan

2014-01-01

Enteroviruses (family of the Picornaviridae) cover a large group of medically important human pathogens for which no antiviral treatment is approved. Although these viruses have been extensively studied, some aspects of the viral life cycle, in particular morphogenesis, are yet poorly understood. We report the discovery of TP219 as a novel inhibitor of the replication of several enteroviruses, including coxsackievirus and poliovirus. We show that TP219 binds directly glutathione (GSH), thereby rapidly depleting intracellular GSH levels and that this interferes with virus morphogenesis without affecting viral RNA replication. The inhibitory effect on assembly was shown not to depend on an altered reducing environment. Using TP219, we show that GSH is an essential stabilizing cofactor during the transition of protomeric particles into pentameric particles. Sequential passaging of coxsackievirus B3 in the presence of low GSH-levels selected for GSH-independent mutants that harbored a surface-exposed methionine in VP1 at the interface between two protomers. In line with this observation, enteroviruses that already contained this surface-exposed methionine, such as EV71, did not rely on GSH for virus morphogenesis. Biochemical and microscopical analysis provided strong evidence for a direct interaction between GSH and wildtype VP1 and a role for this interaction in localizing assembly intermediates to replication sites. Consistently, the interaction between GSH and mutant VP1 was abolished resulting in a relocalization of the assembly intermediates to replication sites independent from GSH. This study thus reveals GSH as a novel stabilizing host factor essential for the production of infectious enterovirus progeny and provides new insights into the poorly understood process of morphogenesis. PMID:24722756

Binding of glutathione to enterovirus capsids is essential for virion morphogenesis.

Directory of Open Access Journals (Sweden)

Hendrik Jan Thibaut

2014-04-01

Full Text Available Enteroviruses (family of the Picornaviridae cover a large group of medically important human pathogens for which no antiviral treatment is approved. Although these viruses have been extensively studied, some aspects of the viral life cycle, in particular morphogenesis, are yet poorly understood. We report the discovery of TP219 as a novel inhibitor of the replication of several enteroviruses, including coxsackievirus and poliovirus. We show that TP219 binds directly glutathione (GSH, thereby rapidly depleting intracellular GSH levels and that this interferes with virus morphogenesis without affecting viral RNA replication. The inhibitory effect on assembly was shown not to depend on an altered reducing environment. Using TP219, we show that GSH is an essential stabilizing cofactor during the transition of protomeric particles into pentameric particles. Sequential passaging of coxsackievirus B3 in the presence of low GSH-levels selected for GSH-independent mutants that harbored a surface-exposed methionine in VP1 at the interface between two protomers. In line with this observation, enteroviruses that already contained this surface-exposed methionine, such as EV71, did not rely on GSH for virus morphogenesis. Biochemical and microscopical analysis provided strong evidence for a direct interaction between GSH and wildtype VP1 and a role for this interaction in localizing assembly intermediates to replication sites. Consistently, the interaction between GSH and mutant VP1 was abolished resulting in a relocalization of the assembly intermediates to replication sites independent from GSH. This study thus reveals GSH as a novel stabilizing host factor essential for the production of infectious enterovirus progeny and provides new insights into the poorly understood process of morphogenesis.

Targeting Aberrant Glutathione Metabolism to Eradicate Human Acute Myelogenous Leukemia Cells*

Science.gov (United States)

Pei, Shanshan; Minhajuddin, Mohammad; Callahan, Kevin P.; Balys, Marlene; Ashton, John M.; Neering, Sarah J.; Lagadinou, Eleni D.; Corbett, Cheryl; Ye, Haobin; Liesveld, Jane L.; O'Dwyer, Kristen M.; Li, Zheng; Shi, Lei; Greninger, Patricia; Settleman, Jeffrey; Benes, Cyril; Hagen, Fred K.; Munger, Joshua; Crooks, Peter A.; Becker, Michael W.; Jordan, Craig T.

2013-01-01

The development of strategies to eradicate primary human acute myelogenous leukemia (AML) cells is a major challenge to the leukemia research field. In particular, primitive leukemia cells, often termed leukemia stem cells, are typically refractory to many forms of therapy. To investigate improved strategies for targeting of human AML cells we compared the molecular mechanisms regulating oxidative state in primitive (CD34+) leukemic versus normal specimens. Our data indicate that CD34+ AML cells have elevated expression of multiple glutathione pathway regulatory proteins, presumably as a mechanism to compensate for increased oxidative stress in leukemic cells. Consistent with this observation, CD34+ AML cells have lower levels of reduced glutathione and increased levels of oxidized glutathione compared with normal CD34+ cells. These findings led us to hypothesize that AML cells will be hypersensitive to inhibition of glutathione metabolism. To test this premise, we identified compounds such as parthenolide (PTL) or piperlongumine that induce almost complete glutathione depletion and severe cell death in CD34+ AML cells. Importantly, these compounds only induce limited and transient glutathione depletion as well as significantly less toxicity in normal CD34+ cells. We further determined that PTL perturbs glutathione homeostasis by a multifactorial mechanism, which includes inhibiting key glutathione metabolic enzymes (GCLC and GPX1), as well as direct depletion of glutathione. These findings demonstrate that primitive leukemia cells are uniquely sensitive to agents that target aberrant glutathione metabolism, an intrinsic property of primary human AML cells. PMID:24089526

Nitric Oxide Ameliorates Zinc Oxide Nanoparticles Phytotoxicity in Wheat Seedlings: Implication of the Ascorbate–Glutathione Cycle

Science.gov (United States)

Tripathi, Durgesh K.; Mishra, Rohit K.; Singh, Swati; Singh, Samiksha; Vishwakarma, Kanchan; Sharma, Shivesh; Singh, Vijay P.; Singh, Prashant K.; Prasad, Sheo M.; Dubey, Nawal K.; Pandey, Avinash C.; Sahi, Shivendra; Chauhan, Devendra K.

2017-01-01

The present study investigates ameliorative effects of nitric oxide (NO) against zinc oxide nanoparticles (ZnONPs) phytotoxicity in wheat seedlings. ZnONPs exposure hampered growth of wheat seedlings, which coincided with reduced photosynthetic efficiency (Fv/Fm and qP), due to increased accumulation of zinc (Zn) in xylem and phloem saps. However, SNP supplementation partially mitigated the ZnONPs-mediated toxicity through the modulation of photosynthetic activity and Zn accumulation in xylem and phloem saps. Further, the results reveal that ZnONPs treatments enhanced levels of hydrogen peroxide and lipid peroxidation (as malondialdehyde; MDA) due to severely inhibited activities of the following ascorbate–glutatione cycle (AsA–GSH) enzymes: ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase and dehydroascorbate reductase, and its associated metabolites ascorbate and glutathione. In contrast to this, the addition of SNP together with ZnONPs maintained the cellular functioning of the AsA–GSH cycle properly, hence lesser damage was noticed in comparison to ZnONPs treatments alone. The protective effect of SNP against ZnONPs toxicity on fresh weight (growth) can be reversed by 2-(4carboxy-2-phenyl)-4,4,5,5-tetramethyl- imidazoline-1-oxyl-3-oxide, a NO scavenger, and thus suggesting that NO released from SNP ameliorates ZnONPs toxicity. Overall, the results of the present study have shown the role of NO in the reducing of ZnONPs toxicity through the regulation of accumulation of Zn as well as the functioning of the AsA–GSH cycle. PMID:28220127

Effect of rosella ( Hibiscus sabdariffa L ) extract on glutathione-S ...

African Journals Online (AJOL)

Purpose: To determine the effect of rosella (Hibiscus sabdariffa L) extract on glutathione-S-trasferase (GST) activity and its hepatoprotective effect. Methods: A total of 25 rats were divided randomly into 5 groups (5 rats per group). Group I served as the baseline, group II was the negative control group, while groups III, IV and ...

Physicochemical and Biological Analysis of 99mTc-Glutathione Radiopharmaceuticals

International Nuclear Information System (INIS)

ME- Sriyani; N- Zainuddin

2013-01-01

99m Tc-glutathion ( 99m Tc-GSH) radiopharmaceutical is available in the GSH lyophilized-kit in which ready to use directly after adding 99m Tc radionuclide. In nuclear medicine, 99m Tc-GSH diagnostic kit is a radiopharmaceutical commonly utilized for cancer diagnoses using imaging method. This paper described the physicochemical and biological characteristics as well as the quality of 99m Tc-GSH diagnostic kit prepared from the GSH lyophilized-kit. The radiochemical purity was determined with thin layer chromatography (TLC) method, performed on a TLC-SG stationary phase with a mobile phase of a dried acetone and 0,9% of NaCl solution. Studies on the effect of volume and radioactivity of Na 99m TcO 4 solution to the radiochemical purity of 99m Tc-GSH were carried out. The sterility of GSH-lyophilized kit and toxicity of 99m Tc-GSH were also investigated. The stability test on GSH lyophilized kit and 99m Tc-GSH in several storage conditions, as well as the plasma stability of 99m Tc-GSH was performed. The analysis result showed that the GSH lyophilized-kit was sterile; the 99m Tc-GSH was non toxic with 99.54 ± 0.01% of radiochemical purity and remained stable 5 hours either at room temperature or 4℃. The volume more than 4 mL of Na 99m TcO 4 solution on the labeling of GSH could decreased the 99m Tc-GSH radiochemical purity, while the radioactivity more than 20 mCi in 7 mL of volume extended the incubation time. In-vitro stability test of 99m Tc-GSH in plasma showed that in the two hours of storage, the radiochemical purity decreased to 51.84 ± 2.52%, and until 5 hours of storage it did not change significantly. From the result, it can be concluded that the GSH lyophilized-kit was remained stable after 13 month of storage either at room temperature or 4℃ with 99% of 99m Tc-GSH radiochemical purity. (author)

Glutathione Redox Control of Asthma: From Molecular Mechanisms to Therapeutic Opportunities

Science.gov (United States)

Jones, Dean P.; Brown, Lou Ann S.

2012-01-01

Abstract Asthma is a chronic inflammatory disorder of the airways associated with airway hyper-responsiveness and airflow limitation in response to specific triggers. Whereas inflammation is important for tissue regeneration and wound healing, the profound and sustained inflammatory response associated with asthma may result in airway remodeling that involves smooth muscle hypertrophy, epithelial goblet-cell hyperplasia, and permanent deposition of airway extracellular matrix proteins. Although the specific mechanisms responsible for asthma are still being unraveled, free radicals such as reactive oxygen species and reactive nitrogen species are important mediators of airway tissue damage that are increased in subjects with asthma. There is also a growing body of literature implicating disturbances in oxidation/reduction (redox) reactions and impaired antioxidant defenses as a risk factor for asthma development and asthma severity. Ultimately, these redox-related perturbations result in a vicious cycle of airway inflammation and injury that is not always amenable to current asthma therapy, particularly in cases of severe asthma. This review will discuss disruptions of redox signaling and control in asthma with a focus on the thiol, glutathione, and reduced (thiol) form (GSH). First, GSH synthesis, GSH distribution, and GSH function and homeostasis are discussed. We then review the literature related to GSH redox balance in health and asthma, with an emphasis on human studies. Finally, therapeutic opportunities to restore the GSH redox balance in subjects with asthma are discussed. Antioxid. Redox Signal. 17, 375–408. PMID:22304503

Intestinal glutathione: determinant of mucosal peroxide transport, metabolism, and oxidative susceptibility

International Nuclear Information System (INIS)

Aw, Tak Yee

2005-01-01

The intestine is a primary site of nutrient absorption and a critical defense barrier against dietary-derived mutagens, carcinogens, and oxidants. Accumulation of oxidants like peroxidized lipids in the gut lumen can contribute to impairment of mucosal metabolic pathways, enterocyte dysfunction independent of cell injury, and development of gut pathologies, such as inflammation and cancer. Despite this recognition, we know little of the pathways of intestinal transport, metabolism, and luminal disposition of dietary peroxides in vivo or of the underlying mechanisms of lipid peroxide-induced genesis of intestinal disease processes. This chapter summarizes our current understanding of the determinants of intestinal absorption and metabolism of peroxidized lipids. I will review experimental evidence from our laboratory and others (Table 1) supporting the pivotal role that glutathione (GSH) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) play in mucosal transport and metabolism of lipid hydroperoxides and how reductant availability can be compromised under chronic stress such as hypoxia, and the influence of GSH on oxidative susceptibility, and redox contribution to genesis of gut disorders. The discussion is pertinent to understanding dietary lipid peroxides and GSH redox balance in intestinal physiology and pathophysiology and the significance of luminal GSH in preserving the integrity of the intestinal epithelium

Alkylating agent induced NRF2 blocks endoplasmic reticulum stress-mediated apoptosis via control of glutathione pools and protein thiol homeostasis

Science.gov (United States)

Zanotto-Filho, Alfeu; Masamsetti, V. Pragathi; Loranc, Eva; Tonapi, Sonal S.; Gorthi, Aparna; Bernard, Xavier; Gonçalves, Rosângela Mayer; Moreira, José C. F.; Chen, Yidong; Bishop, Alexander J. R.

2016-01-01

Alkylating agents are a commonly used cytotoxic class of anticancer drugs. Understanding the mechanisms whereby cells respond to these drugs is key to identify means to improve therapy while reducing toxicity. By integrating genome-wide gene expression profiling, protein analysis and functional cell validation, we herein demonstrated a direct relationship between NRF2 and Endoplasmic Reticulum (ER) stress pathways in response to alkylating agents, which is coordinated by the availability of glutathione (GSH) pools. GSH is essential for both drug detoxification and protein thiol homeostasis within the ER, thus inhibiting ER stress induction and promoting survival; an effect independent of its antioxidant role. NRF2 accumulation induced by alkylating agents resulted in increased GSH synthesis via GCLC/GCLM enzyme, and interfering with this NRF2 response by either NRF2 knockdown or GCLC/GCLM inhibition with buthionine sulfoximine (BSO) caused accumulation of damaged proteins within the ER, leading to PERK-dependent apoptosis. Conversely, upregulation of NRF2, through KEAP1 depletion or NRF2-myc overexpression, or increasing GSH levels with N-acetylcysteine (NAC) or glutathione-ethyl-ester (GSH-E), decreased ER stress and abrogated alkylating agents-induced cell death. Based on these results, we identified a subset of lung and head-and-neck carcinomas with mutations in either KEAP1 or NRF2/NFE2L2 genes that correlate with NRF2 targets overexpression and poor survival. In KEAP1 mutant cancer cells, NRF2 knockdown and GSH depletion increased cell sensitivity via ER stress induction in a mechanism specific to alkylating drugs. Overall, we show that the NRF2-GSH influence on ER homeostasis implicates defects in NRF2-GSH or ER stress machineries as affecting alkylating therapy toxicity. PMID:27638861

Adduct formation of ionic and nanoparticular silver with amino acids and glutathione

International Nuclear Information System (INIS)

Blaske, Franziska; Stork, Lisa; Sperling, Michael; Karst, Uwe

2013-01-01

To investigate the interaction of ionic and nanoparticular silver with amino acids and small peptides, an electrospray ionization time-of-flight mass spectrometry method was developed. Monomeric and oligomeric silver adducts were formed with amino acids including cysteine (Cys), methionine, histidine, lysine, or the tripeptide glutathione (GSH). The obtained spectra for ionic silver show clusters in different ratios between Ag + and the reaction partners (X) including [Ag n X m − (n + 1)H] − (n = 1–4, m = 1–3). Regarding Cys, adduct clusters up to n = 5 and m = 4 were observed as well. Considering silver–GSH interactions, even doubly charged oligomers occur generating [Ag (a+1) GSH a − (a + 3)H] 2− (a = 5–7) and [Ag b GSH b − (b + 2)H] 2− (b = 4–8) ions. 1 H NMR data of free GSH compared to that after treatment with Ag + confirm sulfur–metal interactions due to changing chemical shifts for the protons located adjacent to the thiol group. Density functional theory calculations for silver–GSH clusters may explain the formation of experimentally recorded large clusters due to cooperative effects between silver and carboxylic acid side chains. Both sets of experiments indicate the presence of these adducts in the liquid phase. For silver nanoparticles, the respective data confirm the release of silver ions and the subsequent adduct formation

Adduct formation of ionic and nanoparticular silver with amino acids and glutathione

Science.gov (United States)

Blaske, Franziska; Stork, Lisa; Sperling, Michael; Karst, Uwe

2013-09-01

To investigate the interaction of ionic and nanoparticular silver with amino acids and small peptides, an electrospray ionization time-of-flight mass spectrometry method was developed. Monomeric and oligomeric silver adducts were formed with amino acids including cysteine (Cys), methionine, histidine, lysine, or the tripeptide glutathione (GSH). The obtained spectra for ionic silver show clusters in different ratios between Ag+ and the reaction partners (X) including [Ag n X m - ( n + 1)H]- ( n = 1-4, m = 1-3). Regarding Cys, adduct clusters up to n = 5 and m = 4 were observed as well. Considering silver-GSH interactions, even doubly charged oligomers occur generating [Ag( a + 1)GSH a - ( a + 3)H]2- ( a = 5-7) and [Ag b GSH b - ( b + 2)H]2- ( b = 4-8) ions. 1H NMR data of free GSH compared to that after treatment with Ag+ confirm sulfur-metal interactions due to changing chemical shifts for the protons located adjacent to the thiol group. Density functional theory calculations for silver-GSH clusters may explain the formation of experimentally recorded large clusters due to cooperative effects between silver and carboxylic acid side chains. Both sets of experiments indicate the presence of these adducts in the liquid phase. For silver nanoparticles, the respective data confirm the release of silver ions and the subsequent adduct formation.

Contribution of Arginine 13 to the Catalytic Activity of Human Class Pi Glutathione Transferase P1-1

International Nuclear Information System (INIS)

Kong, Ji Na; Jo, Dong Hyeon; Do, Hyun Dong; Lee, Jin Ju; Kong, Kwang Hoon

2010-01-01

Arg13 is a conserved active-site residue in all known Pi class glutathione S-transferases (GSTs) and in most Alpha class GSTs. To evaluate its contribution to substrate binding and catalysis of this residue, three mutants (R13A, R13K, and R13L) were expressed in Escherichia coli and purified by GSH affinity chromatography. The substitutions of Arg13 significantly affected GSH-conjugation activity, while scarcely affecting glutathione peroxidase or steroid isomerase activities. Mutation of Arg13 into Ala largely reduced the GSH-conjugation activity by approximately 85 - 95%, whereas substitutions by Lys and Leu barely affected activity. These results suggest that, in the GSH-conjugation activity of hGST P1-1, the contribution of Arg13 toward catalytic activity is highly dependent on substrate specificities and the size of the side chain at position 13. From the kinetic parameters, introduction of larger side chains at position 13 results in stronger affinity (Leu > Lys, Arg > Ala) towards GSH. The substitutions of Arg13 with alanine and leucine significantly affected k cat , whereas substitution with Lys was similar to that of the wild type, indicating the significance of a positively charged residue at position 13. From the plots of log (k cat /K m CDNB ) against pH, the pK a values of the thiol group of GSH bound in R13A, R13K, and R13L were estimated to be 1.8, 1.4, and 1.8 pK units higher than the pK a value of the wildtype enzyme, demonstrating the contribution of the Arg13 guanidinium group to the electrostatic field in the active site. From these results, we suggest that contribution of Arg13 in substrate binding is highly dependent on the nature of the electrophilic substrates, while in the catalytic mechanism, it stabilizes the GSH thiolate through hydrogen bonding

Variation of Se, Zn, Co, Fe and Rb distribution in rats upon sequence of injection with SeO2 and glutathione

International Nuclear Information System (INIS)

Czauderna, M.; Samochocka, K.; Kwiathkowska, J.

1984-01-01

The contents of Se, Zn, Co, Fe and Rb in several organs of Wistar rats were determined by instrumental neutron activation analysis (INAA) after injections of SeO 2 and glutathione (GSH). Se was incorporated in all the examined organs, and the efficiency of incorporation does not depend upon the sequence of injection with SeO 2 and GSH. The sequence of these injections affects the contents of the other elements in all the examined organs. (author)

Construction of a subtractive library from hexavalent chromium treated winter flounder (Pseudopleuronectes americanus) reveals alterations in non-selenium glutathione peroxidases

International Nuclear Information System (INIS)

Chapman, Laura M.; Roling, Jonathan A.; Bingham, Lacey K.; Herald, Matt R.; Baldwin, William S.

2004-01-01

Chromium is released during several industrial processes and has accumulated in some estuarine areas. Its effects on mammals have been widely studied, but relatively little information is available on its effects on fish. Gene expression changes are useful biomarkers that can provide information about toxicant exposure and effects, as well as the health of an organism and its ability to adapt to its surroundings. Therefore, we investigated the effects of Cr(VI) on gene expression in the sediment dwelling fish, winter flounder (Pseudopleuronectes americanus). Winter flounder ranging from 300 to 360 g were injected i.p. with Cr(VI) as chromium oxide at 25 μg/kg chromium in 0.15N KCl. Twenty-four hours following injections, winter flounder were euthanized with MS-222 and the livers were excised. Half of the livers were used to make cytosol and the other half were used to isolate mRNA for subtractive hybridization. Subtractive clones obtained were spotted onto nylon filters, which revealed several genes with potentially altered expression due to Cr(VI), including an α class GST, 1-Cys peroxiredoxin (a non-selenium glutathione peroxidase), a P-450 2X subfamily member, two elongation factors (EF-1 gamma and EF-2), and complement component C3. Semi-quantitative RT-PCR was performed and confirmed that Cr(VI) down-regulated complement component C3, an EST, and two potential glutathione peroxidases, GSTA3 and 1-Cys peroxiredoxin. In addition, cytosolic GSH peroxidase activity was reduced, and silver stained SDS-PAGE gels from glutathione-affinity purified cytosol demonstrated that a 27.1 kDa GSH-binding protein was down-regulated greater than 50%. Taken together, Cr(VI) significantly altered the expression of several genes including two potential glutathione peroxidases in winter flounder

Glutathione in Cellular Redox Homeostasis: Association with the Excitatory Amino Acid Carrier 1 (EAAC1

Directory of Open Access Journals (Sweden)

Koji Aoyama

2015-05-01

Full Text Available Reactive oxygen species (ROS are by-products of the cellular metabolism of oxygen consumption, produced mainly in the mitochondria. ROS are known to be highly reactive ions or free radicals containing oxygen that impair redox homeostasis and cellular functions, leading to cell death. Under physiological conditions, a variety of antioxidant systems scavenge ROS to maintain the intracellular redox homeostasis and normal cellular functions. This review focuses on the antioxidant system’s roles in maintaining redox homeostasis. Especially, glutathione (GSH is the most important thiol-containing molecule, as it functions as a redox buffer, antioxidant, and enzyme cofactor against oxidative stress. In the brain, dysfunction of GSH synthesis leading to GSH depletion exacerbates oxidative stress, which is linked to a pathogenesis of aging-related neurodegenerative diseases. Excitatory amino acid carrier 1 (EAAC1 plays a pivotal role in neuronal GSH synthesis. The regulatory mechanism of EAAC1 is also discussed.

Efficient reduction of Cys110 thiyl radical by glutathione in human myoglobin

OpenAIRE

Nagao, Satoshi; Asami, Osamu; Yasui, Hiroyuki; Hirota, Shun

2011-01-01

Human myoglobin (hMb) possesses a cysteine (Cys) residue which is rare among mammalian Mbs. To investigate the effects of this unique Cys residue at the amino acid position 110 (Cys110) on hMb reactions, we studied the reactions of wild type (WT) methMb and its alanine mutant at Cys110 (C110A) with H2O2, particularly in the presence of reduced glutathione (GSH) which is well known as a reducing agent. The formation rates of the ferryloxo (Fe(IV) = O) species by H2O2 under air were about the s...

Up-regulation of glutathione-related genes, enzyme activities and transport proteins in human cervical cancer cells treated with doxorubicin.

Science.gov (United States)

Drozd, Ewa; Krzysztoń-Russjan, Jolanta; Marczewska, Jadwiga; Drozd, Janina; Bubko, Irena; Bielak, Magda; Lubelska, Katarzyna; Wiktorska, Katarzyna; Chilmonczyk, Zdzisław; Anuszewska, Elżbieta; Gruber-Bzura, Beata

2016-10-01

Doxorubicin (DOX), one of the most effective anticancer drugs, acts in a variety of ways including DNA damage, enzyme inhibition and generation of reactive oxygen species. Glutathione (GSH) and glutathione-related enzymes including: glutathione peroxidase (GPX), glutathione reductase (GSR) and glutathione S-transferases (GST) may play a role in adaptive detoxification processes in response to the oxidative stress, thus contributing to drug resistance phenotype. In this study, we investigated effects of DOX treatment on expression and activity of GSH-related enzymes and multidrug resistance-associated proteins in cultured human cervical cancer cells displaying different resistance against this drug (HeLa and KB-V1). Determination of expression level of genes encoding GST isoforms and MRP proteins (GCS, GPX, GSR, GSTA1-3, GSTM1, GSTP1, ABCC1-3, MGST1-3) was performed using StellARray™ Technology. Enzymatic activities of GPX and GSR were measured using biochemical methods. Expression of MRP1 was examined by immunofluorescence microscopy. This study showed that native expression levels of GSTM1 and GSTA3 were markedly higher in KB-V1 cells (2000-fold and 200-fold) compared to HeLa cells. Resistant cells have also shown significantly elevated expression of GSTA1 and GSTA2 genes (200-fold and 50-fold) as a result of DOX treatment. In HeLa cells, exposure to DOX increased expression of all genes: GSTM1 (7-fold) and GSTA1-3 (550-fold, 150-fold and 300-fold). Exposure to DOX led to the slight increase of GCS expression as well as GPX activity in KB-V1 cells, while in HeLa cells it did not. Expression of ABCC1 (MRP1) was not increased in any of the tested cell lines. Our results indicate that expression of GSTM1 and GSTA1-3 genes is up-regulated by DOX treatment and suggest that activity of these genes may be associated with drug resistance of the tested cells. At the same time, involvement of MRP1 in DOX resistance in the given experimental conditions is unlikely

Technetium-99m sestamibi uptake in human breast carcinoma cell lines displaying glutathione-associated drug-resistance

International Nuclear Information System (INIS)

Kabasakal, L.; Oezker, K.; Hayward, M.; Akansel, G.; Griffith, O.; Isitman, A.T.; Hellman, R.; Collier, D.

1996-01-01

An in vitro study was designed to evaluate the uptake of sestamibi (MIBI) in P-glycoprotein (Pgp) and glutathione-associated (GSH) multidrug-resistant (MDR) cell lines. MIBI uptake was studied in various human breast carcinoma cell lines, i.e. in wild-type (MCF7/wt) cells, in adriamycin-resistant (MCF7/adr) cells which express Pgp and in melphalan-resistant (MCF7/mph) cells with increased levels of GSH. The effects of buthiomine sulphoximine (BSO) and verapamil on MIBI uptake were also studied in the MCF7/mph and MCF7/adr cells respectively. The cells were incubated for 1 h with a dose of 0.1 MBq thallium-201 and technetium-99m MIBI. Both BIBI and 201 Tl uptakes were higher for MCF7/mph cells than for the other cells studied. The mean MIBI uptake in MCF7/adr cells was significantly lower than that in MCF7/wt cells (1.9%±0.5% vs 3.1%.0.6%; P 0.1). This study suggests that the uptake of MIBI is not diminished by glutathione-associated drug resistance and that MIBI uptake in a tumour sample does not necessarly indicate that a cancer is sensitive to drugs. (orig.)

The antitumour activity of alkylating agents is not correlated with the levels of glutathione, glutathione transferase and O6-alkylguanine-DNA-alkyltransferase of human tumour xenografts. EORTC SPG and PAMM Groups.

Science.gov (United States)

D'Incalci, M; Bonfanti, M; Pifferi, A; Mascellani, E; Tagliabue, G; Berger, D; Fiebig, H H

1998-10-01

Twenty-three human xenografts, including five colon, five gastric, nine lung (three small cell lung cancer) and four breast carcinomas, were investigated for their sensitivity to nitrosoureas, dacarbazine (DTIC), cyclophosphamide (CTX) and cisplatin (DDP). In 12 cases, at least one of the drugs produced complete or partial remission, in 2, a minor regression was observed and in the other 9, treatment was ineffective. The level of sensitivity to each drug, using a score from 1 to 5, was correlated to three biochemical parameters reported to be involved in resistance to alkylating agents: glutathione (GSH), glutathione transferase (GST) and O6-alkylguanine-DNA-alkyltransferase (AGT). A wide variability was found in these parameters in the xenografts investigated. No correlation was found between any of the three parameters and sensitivity to the drugs used or between sensitivity to one drug and to any of the other drugs tested. These results illustrate the complexity of the question of resistance to alkylating agents and indicate that, at least in xenografts, the biochemical parameters examined are not predictive of response to alkylating agents.

A new metabolic pathway of arsenite: arsenic-glutathione complexes are substrates for human arsenic methyltransferase Cyt19

Energy Technology Data Exchange (ETDEWEB)

Hayakawa, Toru [National Institute for Environmental Studies, Environmental Health Sciences Division, Ibaraki (Japan); Chiba University, Faculty of Pharmaceutical Sciences, Chiba (Japan); Kobayashi, Yayoi; Cui, Xing; Hirano, Seishiro [National Institute for Environmental Studies, Environmental Health Sciences Division, Ibaraki (Japan)

2005-04-01

The metabolism of arsenic is generally accepted to proceed by repetitive reduction and oxidative methylation; the latter is mediated by arsenic methyltransferase (Cyt19). In human urine, the major metabolites of inorganic arsenicals such as arsenite (iAs{sup III}) and arsenate (iAs{sup V}) are monomethylarsonic acid (MMA{sup V}) and dimethylarsinic acid (DMA{sup V}). On the other hand, in rat bile, the major metabolites of iAs{sup III} have been reported to be arsenic-glutathione (As-GSH) complexes. In the present study we investigate whether these As-GSH complexes are substrates for arsenic methyltransferase by using human recombinant Cyt19. Analyses by high-performance liquid chromatography-inductively coupled plasma mass spectrometry suggested that arsenic triglutathione (ATG) was generated nonenzymatically from iAs{sup III} when GSH was present at concentrations 2 mM or higher. Human recombinant Cyt19 catalyzed transfer of a methyl group from S-adenosyl-l-methionine to arsenic and produced monomethyl and dimethyl arsenicals. The methylation of arsenic was catalyzed by Cyt19 only when ATG was present in the reaction mixture. Moreover, monomethylarsonic diglutathione (MADG) was a substrate of Cyt19 for further methylation to dimethylarsinic glutathione (DMAG). On the other hand, monomethylarsonous acid (MMA{sup III}), a hydrolysis product of MADG, was not methylated to dimethyl arsenical by Cyt19. These results suggest that As-GSH complexes such as ATG and MADG were converted by Cyt19 to MADG and DMAG, respectively. Both MADG and DMAG were unstable in solution when the GSH concentration was lower than 1 mM, and were hydrolyzed and oxidized to MMA{sup V} and DMA{sup V}, respectively. Metabolism of iAs{sup III} to methylated arsenicals by Cyt19 was via ATG and MADG rather than by oxidative methylation of iAs{sup III} and MMA{sup III}. (orig.)

Comparison of radiation-induced DNA-protein cross-links formed in oxic, hypoxic, and glutathione depleted cells

International Nuclear Information System (INIS)

Xue, L.; Friedman, L.R.; Chiu, S.; Ramakrishnan, N.; Oleinick, N.L.

1987-01-01

Treatment of cells with L-buthionine sulfoximine (BSO) inhibits the synthesis of glutathione (GSH). Subsequent metabolism depletes the cells of GSH. GSH-depletion sensitizes both oxic and hypoxic cells to the lethal effects of ionizing radiation. DNA-protein cross-links (DPC) are formed preferentially between DNA sequences active in transcription and a subset of proteins of the nuclear matrix. Thus, DPC may be an indicator lesion of damage in sensitive regions of the genome. The interrelationships between GSH level, oxic vs. hypoxic status, and the yield of DPC have been studied in terms of number of lesions and repair rate in Chinese hamster V79 and in human lung carcinoma A549 cells. The data suggest that elevated background levels of DPC are indicative of a reduced repair capacity, and greater radiation-induced yields of DPC in hypoxia may also be indicative of a compromised repair mechanism

Evaluation of cysteine ethyl ester as efficient inducer for glutathione overproduction in Saccharomyces spp.

Science.gov (United States)

Lorenz, Eric; Schmacht, Maximilian; Senz, Martin

2016-11-01

Economical yeast based glutathione (GSH) production is a process that is influenced by several factors like raw material and production costs, biomass production and efficient biotransformation of adequate precursors into the final product GSH. Nowadays the usage of cysteine for the microbial conversion into GSH is industrial state of practice. In the following study, the potential of different inducers to increase the GSH content was evaluated by means of design of experiments methodology. Investigations were executed in three natural Saccharomyces strains, S. cerevisiae, S. bayanus and S. boulardii, in a well suited 50ml shake tube system. Results of shake tube experiments were confirmed in traditional baffled shake flasks and finally via batch cultivation in lab-scale bioreactors under controlled conditions. Comprehensive studies showed that the usage of cysteine ethyl ester (CEE) for the batch-wise biotransformation into GSH led up to a more than 2.2 times higher yield compared to cysteine as inducer. Additionally, the intracellular GSH content could be significantly increased for all strains in terms of 2.29±0.29% for cysteine to 3.65±0.23% for CEE, respectively, in bioreactors. Thus, the usage of CEE provides a highly attractive inducing strategy for the GSH overproduction. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of glutathione aerosol on oxidant-antioxidant imbalance in idiopathic pulmonary fibrosis.

Science.gov (United States)

Borok, Z; Buhl, R; Grimes, G J; Bokser, A D; Hubbard, R C; Holroyd, K J; Roum, J H; Czerski, D B; Cantin, A M; Crystal, R G

1991-07-27

Idiopathic pulmonary fibrosis (IPF) is characterised by alveolar inflammation, exaggerated release of oxidants, and subnormal concentrations of the antioxidant glutathione in respiratory epithelial lining fluid (ELF). Glutathione (600 mg twice daily for 3 days) was given by aerosol to 10 patients with IPF. Total ELF glutathione rose transiently, ELF oxidised glutathione concentrations increased, and there was a decrease in spontaneous superoxide anion release by alveolar macrophages. Thus, glutathione by aerosol could be a means of reversing the oxidant-antioxidant imbalance in IPF.

Toxicity of isoproturon on Saccharomyces cerevisiae growing in mineral medium depends on glutathione-mediated antioxidant capacity.

OpenAIRE

Candeias, M; Alves-Pereira, I; Ferreira, Rui

2011-01-01

The results revealed an increase of viable cells, after 72 h of culture and an increase of antioxidant power mediated by GSH and GR activity in S. cerevisiae UE-ME3. The adaptive response of UE-ME3 strain to isoproturon, determined in MB, was clearly higher than observed in IGC-3507 strain. So, we presume that the extent of the toxic effect of isoproturon in both yeast strains depends on glutathione-mediated antioxidant capacity.

Gold nanoparticles-immobilized, hierarchically ordered, porous TiO2 nanotubes for biosensing of glutathione

Directory of Open Access Journals (Sweden)

Sheen Mers SV

2015-10-01

Full Text Available SV Sheen Mers,1,2 Elumalai Thambuswamy Deva Kumar,1 V Ganesh1,2 1Electrodics and Electrocatalysis (EEC Division, Council of Scientific and Industrial Research–Central Electrochemical Research Institute (CSIR–CECRI, Karaikudi, Tamil Nadu, India; 2Academy of Scientific and Innovative Research (AcSIR, New Delhi, India Abstract: Glutathione (GSH is vital for several functions of our human body such as neutralization of free radicals and reactive oxygen compounds, maintaining the active forms of vitamin C and E, regulation of nitric oxide cycle, iron metabolism, etc. It is also an endogenous antioxidant in most of the biological reactions. Given the importance of GSH, a simple strategy is proposed in this work to develop a biosensor for quantitative detection of GSH. This particular biosensor comprises of gold nanoparticles (Au NPs-immobilized, hierarchically ordered titanium dioxide (TiO2 porous nanotubes. Hexagonally arranged, honeycomb-like nanoporous tubular TiO2 electrodes are prepared by using a simple electrochemical anodization process by applying a constant potential of 30 V for 24 hours using ethylene glycol consisting of ammonium fluoride as an electrolytic medium. Structural morphology and crystalline nature of such TiO2 nanotubes are analyzed using field emission scanning electron microscope (FESEM and X-ray diffraction (XRD. Interestingly, nanocomposites of TiO2 with Au NPs is prepared in an effort to alter the intrinsic properties of TiO2, especially tuning of its band gap. Au NPs are prepared by a well-known Brust and Schiffrin method and are immobilized onto TiO2 electrodes which act as a perfect electrochemical sensing platform for GSH detection. Structural characterization and analysis of these modified electrodes are performed using FESEM, XRD, and UV-visible spectroscopic studies. GSH binding events on Au NPs-immobilized porous TiO2 electrodes are monitored by electrochemical techniques, namely, cyclic voltammetry (CV and

Total cysteine and glutathione determination in hemolymph of individual adult D. melanogaster

Energy Technology Data Exchange (ETDEWEB)

Borra, Srivani, E-mail: sborra3@uic.edu [Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, 4323 SES, MC 111, Chicago, IL 60607 (United States); Featherstone, David E., E-mail: def@uic.edu [Department of Biological Sciences, University of Illinois at Chicago, 840 West Taylor Street, SEL 4311, M/C 067, Chicago, IL 60607 (United States); Laboratory of Integrative Neuroscience, University of Illinois at Chicago, 840 West Taylor Street, SEL 4311, M/C 067, Chicago, IL 60607 (United States); Shippy, Scott A., E-mail: sshippy@uic.edu [Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, 5417 SES, MC 111, Chicago, IL 60607 (United States); Laboratory of Integrative Neuroscience, University of Illinois at Chicago, 840 West Taylor Street, SEL 4311, M/C 067, Chicago, IL 60607 (United States)

2015-01-01

Highlights: • Method for highly volume variant, nL sample assay of biological relevant thiols. • Defined capillary lengths used to deliver nL sample and reagent volumes. • Optimized reagent concentrations, reaction times and temperatures for thiol assay. • Total cysteine and glutathione measured from hemolymph of individual fruit flies. - Abstract: Determination of thiols, glutathione (GSH) and cysteine (Cys) are important due to their roles in oxidative stress and aging. Oxidants such as soluble O{sub 2} and H{sub 2}O{sub 2} promote oxidation of thiols to disulfide (-S-S-) bonded dimers affecting quantitation accuracy. The method presented here reduces disulfide-bonded species followed by fluorescence labelling of the 29.5 (±18.2) nL hemolymph volumes of individual adult Drosophila Melanogaster. The availability of only tens of nanoliter (nL) samples that are also highly volume variant requires efficient sample handling to improve thiol measurements while minimizing sample dilution. The optimized method presented here utilizes defined lengths of capillaries to meter tris(2-carboxyethyl)phosphine reducing reagent and monobromobimane derivatizing reagent volumes enabling Cys and GSH quantitation with only 20-fold dilution. The nL assay developed here was optimized with respect to reagent concentrations, sample dilution, reaction times and temperatures. Separation and identification of the nL thiol mixtures were obtained with capillary electrophoresis-laser induced fluorescence. To demonstrate the capability of this method total Cys and total GSH were measured in the hemolymph collected from individual adult D. Melanogaster. The thiol measurements were used to compare a mutant fly strain with a non-functional cystine–glutamate transporter (xCT) to its background control. The mutant fly, genderblind (gb), carries a non-functional gene for a protein similar to mammalian xCT whose function is not fully understood. Average concentrations obtained for mutant

Alkylating Agent-Induced NRF2 Blocks Endoplasmic Reticulum Stress-Mediated Apoptosis via Control of Glutathione Pools and Protein Thiol Homeostasis.

Science.gov (United States)

Zanotto-Filho, Alfeu; Masamsetti, V Pragathi; Loranc, Eva; Tonapi, Sonal S; Gorthi, Aparna; Bernard, Xavier; Gonçalves, Rosângela Mayer; Moreira, José C F; Chen, Yidong; Bishop, Alexander J R

2016-12-01

Alkylating agents are a commonly used cytotoxic class of anticancer drugs. Understanding the mechanisms whereby cells respond to these drugs is key to identify means to improve therapy while reducing toxicity. By integrating genome-wide gene expression profiling, protein analysis, and functional cell validation, we herein demonstrated a direct relationship between NRF2 and Endoplasmic Reticulum (ER) stress pathways in response to alkylating agents, which is coordinated by the availability of glutathione (GSH) pools. GSH is essential for both drug detoxification and protein thiol homeostasis within the ER, thus inhibiting ER stress induction and promoting survival, an effect independent of its antioxidant role. NRF2 accumulation induced by alkylating agents resulted in increased GSH synthesis via GCLC/GCLM enzyme, and interfering with this NRF2 response by either NRF2 knockdown or GCLC/GCLM inhibition with buthionine sulfoximine caused accumulation of damaged proteins within the ER, leading to PERK-dependent apoptosis. Conversely, upregulation of NRF2, through KEAP1 depletion or NRF2-myc overexpression, or increasing GSH levels with N-acetylcysteine or glutathione-ethyl-ester, decreased ER stress and abrogated alkylating agents-induced cell death. Based on these results, we identified a subset of lung and head-and-neck carcinomas with mutations in either KEAP1 or NRF2/NFE2L2 genes that correlate with NRF2 target overexpression and poor survival. In KEAP1-mutant cancer cells, NRF2 knockdown and GSH depletion increased cell sensitivity via ER stress induction in a mechanism specific to alkylating drugs. Overall, we show that the NRF2-GSH influence on ER homeostasis implicates defects in NRF2-GSH or ER stress machineries as affecting alkylating therapy toxicity. Mol Cancer Ther; 15(12); 3000-14. ©2016 AACR. ©2016 American Association for Cancer Research.

Docosahexaenoic acid prevents paraquat-induced reactive oxygen species production in dopaminergic neurons via enhancement of glutathione homeostasis

Energy Technology Data Exchange (ETDEWEB)

Lee, Hyoung Jun; Han, Jeongsu; Jang, Yunseon; Kim, Soo Jeong; Park, Ji Hoon; Seo, Kang Sik [Department of Biochemistry, College of Medicine, Chungnam National University, Daejeon (Korea, Republic of); Jeong, Soyeon; Shin, Soyeon; Lim, Kyu [Department of Biochemistry, College of Medicine, Chungnam National University, Daejeon (Korea, Republic of); Infection Signaling Network Research Center, Chungnam National University, Daejeon (Korea, Republic of); Heo, Jun Young, E-mail: junyoung3@gmail.com [Brainscience Institute, Chungnam National University, Daejeon (Korea, Republic of); Kweon, Gi Ryang, E-mail: mitochondria@cnu.ac.kr [Department of Biochemistry, College of Medicine, Chungnam National University, Daejeon (Korea, Republic of); Infection Signaling Network Research Center, Chungnam National University, Daejeon (Korea, Republic of)

2015-01-30

Highlights: • DHA prevents PQ-induced dopaminergic neuronal loss via decreasing of excessive ROS. • DHA increases GR and GCLm derivate GSH pool by enhancement of Nrf2 expression. • Protective mechanism is removal of PQ-induced ROS via DHA-dependent GSH pool. • DHA may be a good preventive strategy for Parkinson’s disease (PD) therapy. - Abstract: Omega-3 polyunsaturated fatty acid levels are reduced in the substantia nigra area in Parkinson’s disease patients and animal models, implicating docosahexaenoic acid (DHA) as a potential treatment for preventing Parkinson’s disease and suggesting the need for investigations into how DHA might protect against neurotoxin-induced dopaminergic neuron loss. The herbicide paraquat (PQ) induces dopaminergic neuron loss through the excessive production of reactive oxygen species (ROS). We found that treatment of dopaminergic SN4741 cells with PQ reduced cell viability in a dose-dependent manner, but pretreatment with DHA ameliorated the toxic effect of PQ. To determine the toxic mechanism of PQ, we measured intracellular ROS content in different organelles with specific dyes. As expected, all types of ROS were increased by PQ treatment, but DHA pretreatment selectively decreased cytosolic hydrogen peroxide content. Furthermore, DHA treatment-induced increases in glutathione reductase and glutamate cysteine ligase modifier subunit (GCLm) mRNA expression were positively correlated with glutathione (GSH) content. Consistent with this increase in GCLm mRNA levels, Western blot analysis revealed that DHA pretreatment increased nuclear factor-erythroid 2 related factor 2 (Nrf2) protein levels. These findings indicate that DHA prevents PQ-induced neuronal cell loss by enhancing Nrf2-regulated GSH homeostasis.

Docosahexaenoic acid prevents paraquat-induced reactive oxygen species production in dopaminergic neurons via enhancement of glutathione homeostasis

International Nuclear Information System (INIS)

Lee, Hyoung Jun; Han, Jeongsu; Jang, Yunseon; Kim, Soo Jeong; Park, Ji Hoon; Seo, Kang Sik; Jeong, Soyeon; Shin, Soyeon; Lim, Kyu; Heo, Jun Young; Kweon, Gi Ryang

2015-01-01

Highlights: • DHA prevents PQ-induced dopaminergic neuronal loss via decreasing of excessive ROS. • DHA increases GR and GCLm derivate GSH pool by enhancement of Nrf2 expression. • Protective mechanism is removal of PQ-induced ROS via DHA-dependent GSH pool. • DHA may be a good preventive strategy for Parkinson’s disease (PD) therapy. - Abstract: Omega-3 polyunsaturated fatty acid levels are reduced in the substantia nigra area in Parkinson’s disease patients and animal models, implicating docosahexaenoic acid (DHA) as a potential treatment for preventing Parkinson’s disease and suggesting the need for investigations into how DHA might protect against neurotoxin-induced dopaminergic neuron loss. The herbicide paraquat (PQ) induces dopaminergic neuron loss through the excessive production of reactive oxygen species (ROS). We found that treatment of dopaminergic SN4741 cells with PQ reduced cell viability in a dose-dependent manner, but pretreatment with DHA ameliorated the toxic effect of PQ. To determine the toxic mechanism of PQ, we measured intracellular ROS content in different organelles with specific dyes. As expected, all types of ROS were increased by PQ treatment, but DHA pretreatment selectively decreased cytosolic hydrogen peroxide content. Furthermore, DHA treatment-induced increases in glutathione reductase and glutamate cysteine ligase modifier subunit (GCLm) mRNA expression were positively correlated with glutathione (GSH) content. Consistent with this increase in GCLm mRNA levels, Western blot analysis revealed that DHA pretreatment increased nuclear factor-erythroid 2 related factor 2 (Nrf2) protein levels. These findings indicate that DHA prevents PQ-induced neuronal cell loss by enhancing Nrf2-regulated GSH homeostasis

Supramolecular interactions of oxidative stress biomarker glutathione with fluorone black

Science.gov (United States)

Hepel, Maria; Stobiecka, Magdalena

2018-03-01

Oxidative stress biomarkers, including glutathione (GSH) and related compounds, are involved in a variety of interactions enabling redox potential maintenance in living cells and protection against radicals. Since the oxidative stress is promoting and, in many cases, inducing serious illnesses, monitoring of GSH levels can aid in diagnostics and disease prevention. Herein, we report on the discovery of the formation of a supramolecular ensemble of GSH with fluorone black (9-phenyl fluorone, FB) which is optically active and enables sensitive determination of GSH by resonance elastic light scattering (RELS). We have found that supramolecular interactions of GSH with FB can be probed with spectroscopic, RELS, and electrochemical methods. Our investigations show that RELS intensity for FB solutions increases with GSH concentration while fluorescence emission of FB is not affected, as quenching begins only above 0.8 mM GSH. The UV-Vis difference spectra show a positive peak at 383 nm and a negative peak at 458 nm, indicating a higher-energy absorbing complex in comparison to the non-bonded FB host. Supramolecular interactions of FB with GSH have also been corroborated by electrochemical measurements involving two configurations of FB-GSH ensembles on electrodes: (i) an inverted orientation on Au-coated quartz crystal piezoelectrode (Au@SG-FB), with strong thiolate bonding to gold, and (ii) a non-inverted orientation on glassy carbon electrode (GCE@FB-GS), with weak π-π stacking attachment and efficient charge mediation through the ensemble. The formation of a supramolecular ensemble with hydrogen bonding has also been confirmed by quantum mechanical calculations. The discovery of supramolecular FB-GSH ensemble formation enables elucidating the mechanisms of strong RELS responses, changes in UV-Vis absorption spectra, and the electrochemical reactivity. Also, it provides new insights to the understanding of the efficient charge-transfer in redox potential homeostasis

Supramolecular interactions of oxidative stress biomarker glutathione with fluorone black.

Science.gov (United States)

Hepel, Maria; Stobiecka, Magdalena

2018-03-05

Oxidative stress biomarkers, including glutathione (GSH) and related compounds, are involved in a variety of interactions enabling redox potential maintenance in living cells and protection against radicals. Since the oxidative stress is promoting and, in many cases, inducing serious illnesses, monitoring of GSH levels can aid in diagnostics and disease prevention. Herein, we report on the discovery of the formation of a supramolecular ensemble of GSH with fluorone black (9-phenyl fluorone, FB) which is optically active and enables sensitive determination of GSH by resonance elastic light scattering (RELS). We have found that supramolecular interactions of GSH with FB can be probed with spectroscopic, RELS, and electrochemical methods. Our investigations show that RELS intensity for FB solutions increases with GSH concentration while fluorescence emission of FB is not affected, as quenching begins only above 0.8mM GSH. The UV-Vis difference spectra show a positive peak at 383nm and a negative peak at 458nm, indicating a higher-energy absorbing complex in comparison to the non-bonded FB host. Supramolecular interactions of FB with GSH have also been corroborated by electrochemical measurements involving two configurations of FB-GSH ensembles on electrodes: (i) an inverted orientation on Au-coated quartz crystal piezoelectrode (Au@SG-FB), with strong thiolate bonding to gold, and (ii) a non-inverted orientation on glassy carbon electrode (GCE@FB-GS), with weak π-π stacking attachment and efficient charge mediation through the ensemble. The formation of a supramolecular ensemble with hydrogen bonding has also been confirmed by quantum mechanical calculations. The discovery of supramolecular FB-GSH ensemble formation enables elucidating the mechanisms of strong RELS responses, changes in UV-Vis absorption spectra, and the electrochemical reactivity. Also, it provides new insights to the understanding of the efficient charge-transfer in redox potential homeostasis

Glutathione requirement for the rejoining of radiation-induced DNA breaks in misonidazole-treated cells

International Nuclear Information System (INIS)

Edgren, M.; Revesz, L.

1985-01-01

The role of glutathione (GSH) in the rejoining of radiation-induced single-strand DNA breaks (ssb) was studied in human fibroblast cultures sensitized to radiation by a 30 min treatment with 1 mM misonidazole (MISO). Hypoxically irradiated cells, deficient in GSH, either inherently, or due to a 16 h incubation with 1 mM buthionine sulphoximine (BSO), rejoined the breaks after MISO treatment at a lower rate and to a lesser extent than did GSH-proficient cells. Without MISO treatment, the hypoxically induced ssb were rejoined in the GSH-deficient cells as effectively as in the proficient cells. It is concluded that a large proportion of the breaks which arise after hypoxic irradiation in the presence of MISO are of a different type to those which arise in the absence of the drug, and require a particular GSH-dependent, enzymatic repair system. This requirement for rejoining in hypoxically irradiated, MISO-treated cells is similar to that seen earlier in MISO-untreated, oxically irradiated cells, and suggests that the ssb induced by radiation in the presence of MISO or oxygen are of a similar nature. (author)

Effects of hepatocyte growth factor on glutathione synthesis, growth, and apoptosis is cell density-dependent

International Nuclear Information System (INIS)

Yang Heping; Magilnick, Nathaniel; Xia Meng; Lu, Shelly C.

2008-01-01

Hepatocyte growth factor (HGF) is a potent hepatocyte mitogen that exerts opposing effects depending on cell density. Glutathione (GSH) is the main non-protein thiol in mammalian cells that modulates growth and apoptosis. We previously showed that GSH level is inversely related to cell density of hepatocytes and is positively related to growth. Our current work examined whether HGF can modulate GSH synthesis in a cell density-dependent manner and how GSH in turn influence HGF's effects. We found HGF treatment of H4IIE cells increased cell GSH levels only under subconfluent density. The increase in cell GSH under low density was due to increased transcription of GSH synthetic enzymes. This correlated with increased protein levels and nuclear binding activities of c-Jun, c-Fos, p65, p50, Nrf1 and Nrf2 to the promoter region of these genes. HGF acts as a mitogen in H4IIE cells under low cell density and protects against tumor necrosis factor α (TNFα)-induced apoptosis by limiting JNK activation. However, HGF is pro-apoptotic under high cell density and exacerbates TNFα-induced apoptosis by potentiating JNK activation. The increase in cell GSH under low cell density allows HGF to exert its full mitogenic effect but is not necessary for its anti-apoptotic effect

Glutathione-dependent responses of plants to drought: a review

Directory of Open Access Journals (Sweden)

Mateusz Labudda

2014-02-01

Full Text Available Water is a renewable resource. However, with the human population growth, economic development and improved living standards, the world’s supply of fresh water is steadily decreasing and consequently water resources for agricultural production are limited and diminishing. Water deficiency is a significant problem in agriculture and increasing efforts are currently being made to understand plant tolerance mechanisms and to develop new tools (especially molecular that could underpin plant breeding and cultivation. However, the biochemical and molecular mechanisms of plant water deficit tolerance are not fully understood, and the data available is incomplete. Here, we review the significance of glutathione and its related enzymes in plant responses to drought. Firstly, the roles of reduced glutathione and reduced/oxidized glutathione ratio, are discussed, followed by an extensive discussion of glutathione related enzymes, which play an important role in plant responses to drought. Special attention is given to the S-glutathionylation of proteins, which is involved in cell metabolism regulation and redox signaling in photosynthetic organisms subjected to abiotic stress. The review concludes with a brief overview of future perspectives for the involvement of glutathione and related enzymes in drought stress responses.

Photoaffinity labelling of the active site of the rat glutathione transferases 3-3 and 1-1 and human glutathione transferase A1-1.

OpenAIRE

Cooke, R J; Björnestedt, R; Douglas, K T; McKie, J H; King, M D; Coles, B; Ketterer, B; Mannervik, B

1994-01-01

The glutathione transferases (GSTs) form a group of enzymes responsible for a wide range of molecular detoxications. The photoaffinity label S-(2-nitro-4-azidophenyl)glutathione was used to study the hydrophobic region of the active site of the rat liver GST 1-1 and 2-2 isoenzymes (class Alpha) as well as the rat class-Mu GST 3-3. Photoaffinity labelling was carried out using a version of S-(2-nitro-4-azidophenyl)glutathione tritiated in the arylazido ring. The labelling occurred with higher ...

Characterization of glutathione transferases involved in the pathogenicity of Alternaria brassicicola.

Science.gov (United States)

Calmes, Benoit; Morel-Rouhier, Mélanie; Bataillé-Simoneau, Nelly; Gelhaye, Eric; Guillemette, Thomas; Simoneau, Philippe

2015-06-18

Glutathione transferases (GSTs) represent an extended family of multifunctional proteins involved in detoxification processes and tolerance to oxidative stress. We thus anticipated that some GSTs could play an essential role in the protection of fungal necrotrophs against plant-derived toxic metabolites and reactive oxygen species that accumulate at the host-pathogen interface during infection. Mining the genome of the necrotrophic Brassica pathogen Alternaria brassicicola for glutathione transferase revealed 23 sequences, 17 of which could be clustered into the main classes previously defined for fungal GSTs and six were 'orphans'. Five isothiocyanate-inducible GSTs from five different classes were more thoroughly investigated. Analysis of their catalytic properties revealed that two GSTs, belonging to the GSTFuA and GTT1 classes, exhibited GSH transferase activity with isothiocyanates (ITC) and peroxidase activity with cumene hydroperoxide, respectively. Mutant deficient for these two GSTs were however neither more susceptible to ITC nor less aggressive than the wild-type parental strain. By contrast mutants deficient for two other GSTs, belonging to the Ure2pB and GSTO classes, were distinguished by their hyper-susceptibility to ITC and low aggressiveness against Brassica oleracea. In particular AbGSTO1 could participate in cell tolerance to ITC due to its glutathione-dependent thioltransferase activity. The fifth ITC-inducible GST belonged to the MAPEG class and although it was not possible to produce the soluble active form of this protein in a bacterial expression system, the corresponding deficient mutant failed to develop normal symptoms on host plant tissues. Among the five ITC-inducible GSTs analyzed in this study, three were found essential for full aggressiveness of A. brassicicola on host plant. This, to our knowledge is the first evidence that GSTs might be essential virulence factors for fungal necrotrophs.

Metabolic requirements associated with GSH synthesis during in vitro maturation of cattle oocytes.

Science.gov (United States)

Furnus, C C; de Matos, D G; Picco, S; García, P Peral; Inda, A M; Mattioli, G; Errecalde, A L

2008-12-01

Glutathione (GSH) concentration increases in bovine oocytes during in vitro maturation (IVM). The constitutive amino acids involved in GSH synthesis are glycine (Gly), glutamate (Glu) and cysteine (Cys). The present study was conducted to investigate the effect of the availability of glucose, Cys, Gly and Glu on GSH synthesis during IVM. The effect of the amino acid serine (Ser) on intracellular reduced/oxidized glutathione (GSH/GSSG) content in both oocytes and cumulus cells was also studied. Cumulus-oocyte complexes (COC) of cattle obtained from ovaries collected from an abattoir were matured in synthetic oviduct fluid (SOF) medium containing 8 mg/ml bovine serum albumin-fatty acid-free (BSA-FAF), 10 microg/ml LH, 1 microg/ml porcine FSH (pFSH) and 1 microg/ml 17 beta-estradiol (17beta-E2). GSH/GSSG content was measured using a double-beam spectrophotometer. The COC were cultured in SOF supplemented with 1.5mM or 5.6mM glucose (Exp. 1); with or without Cys+Glu+Gly (Exp. 2); with the omission of one constitutive GSH amino acid (Exp. 3); with 0.6mM Cys or Cys+Ser (Exp. 4). The developmental capacity of oocytes matured in IVM medium supplemented with Cys and the cell number per blastocyst were determined (Exp. 5). The results reported here indicate (1) no differences in the intracellular GSH/GSSG content at any glucose concentrations. Also, cumulus cell number per COC did not differ either before or after IVM (Exp. 1). (2) Glutathione content in oocytes matured in SOF alone were significantly different from oocytes incubated with SOF supplemented with Cys+Glu+Gly (Exp. 2). (3) Addition of Cys to maturation medium, either with or without Gly and Glu supplementation resulted in an increase of GSH/GSSG content. However, when Cys was omitted from the IVM medium intracellular GSH in oocytes or cumulus cells was less but not significantly altered compared to SOF alone (Exp. 3). (4) Glutathione content in both oocytes and cumulus cells was significantly reduced by

Ajoene restored behavioral patterns and liver glutathione level in morphine treated C57BL6 mice.

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Yun, Jaesuk; Oliynyk, Sergiy; Lee, Yeonju; Kim, Jieun; Yun, Kyunghwa; Jeon, Raok; Ryu, Jae-Ha; Oh, Seikwan

2017-01-01

Oxidative stress exacerbates drug dependence induced by administration of opiate analgesics such as morphine-induced tolerance and physical dependence associated with the reduction in hepatic glutathione (GSH) level. Ajoene obtained from garlic (Allium sativum L.) has been reported for anti-tumorigenic, anti-oxidative and neuroprotective properties, however, little is known about its effect on morphine-induced dependence. Therefore, this study aimed at the effect of ajoene on physical and/or psychological dependence and liver GSH content in morphine-treated mice. Conditioned place preference (CPP) test and measurement of morphine withdrawal syndrome were performed in C57BL6 mice for behavioral experiments. Thereafter, mice were sacrificed for measurement of serum and liver GSH levels. Ajoene restored CPP and naloxone-precipitated jumping behavior in mice exposed to morphine. Moreover, the reduced level of liver GSH content in morphine treated mice was back to normal after ajoene administration. Taken together, ajoene improved behavioral patterns in mice exposed to morphine suggesting its potential therapeutic benefit against morphine-induced dependence.

Adduct formation of ionic and nanoparticular silver with amino acids and glutathione

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Blaske, Franziska; Stork, Lisa; Sperling, Michael; Karst, Uwe, E-mail: uk@uni-muenster.de [University of Muenster, Institute of Inorganic and Analytical Chemistry (Germany)

2013-09-15

To investigate the interaction of ionic and nanoparticular silver with amino acids and small peptides, an electrospray ionization time-of-flight mass spectrometry method was developed. Monomeric and oligomeric silver adducts were formed with amino acids including cysteine (Cys), methionine, histidine, lysine, or the tripeptide glutathione (GSH). The obtained spectra for ionic silver show clusters in different ratios between Ag{sup +} and the reaction partners (X) including [Ag{sub n}X{sub m} - (n + 1)H]{sup -} (n = 1-4, m = 1-3). Regarding Cys, adduct clusters up to n = 5 and m = 4 were observed as well. Considering silver-GSH interactions, even doubly charged oligomers occur generating [Ag{sub (a+1)}GSH{sub a} - (a + 3)H]{sup 2-} (a = 5-7) and [Ag{sub b}GSH{sub b} - (b + 2)H]{sup 2-} (b = 4-8) ions. {sup 1}H NMR data of free GSH compared to that after treatment with Ag{sup +} confirm sulfur-metal interactions due to changing chemical shifts for the protons located adjacent to the thiol group. Density functional theory calculations for silver-GSH clusters may explain the formation of experimentally recorded large clusters due to cooperative effects between silver and carboxylic acid side chains. Both sets of experiments indicate the presence of these adducts in the liquid phase. For silver nanoparticles, the respective data confirm the release of silver ions and the subsequent adduct formation.

Oxygen enhancement ratios for glutathione-deficient human fibroblasts determined from the frequency of radiation induced micronuclei

International Nuclear Information System (INIS)

Midander, J.

1982-01-01

The yield of micronuclei (MN) was determined to study the radiosensitizing effect of oxygen on three human fibroblast strains, characterized by genetically defined differences in their glutathione (GSH) level. Cells were irradiated in paired experiments with x-ray doses of 2.66 and 6.65 gy in their exponential growth phase in a monolayer under oxic and anoxic conditions. Results indicated a reduced oxygen effect for the GSH deficient cells, the reduction of o.e.r. being most pronounced in the case of GSHsup(-/-) cells, when it was close to unity. The o.e.r. value was intermediate for the GSHsup(+/-) in comparison with the two other cell strains. It is concluded that the data indicate a correlation between the cellular content of GSH and the oxygen enhancement of the formation of micronuclei after irradiation. (U.K.)

Glutathione provides a source of cysteine essential for intracellular multiplication of Francisella tularensis.

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Khaled Alkhuder

2009-01-01

Full Text Available Francisella tularensis is a highly infectious bacterium causing the zoonotic disease tularemia. Its ability to multiply and survive in macrophages is critical for its virulence. By screening a bank of HimarFT transposon mutants of the F. tularensis live vaccine strain (LVS to isolate intracellular growth-deficient mutants, we selected one mutant in a gene encoding a putative gamma-glutamyl transpeptidase (GGT. This gene (FTL_0766 was hence designated ggt. The mutant strain showed impaired intracellular multiplication and was strongly attenuated for virulence in mice. Here we present evidence that the GGT activity of F. tularensis allows utilization of glutathione (GSH, gamma-glutamyl-cysteinyl-glycine and gamma-glutamyl-cysteine dipeptide as cysteine sources to ensure intracellular growth. This is the first demonstration of the essential role of a nutrient acquisition system in the intracellular multiplication of F. tularensis. GSH is the most abundant source of cysteine in the host cytosol. Thus, the capacity this intracellular bacterial pathogen has evolved to utilize the available GSH, as a source of cysteine in the host cytosol, constitutes a paradigm of bacteria-host adaptation.

Hemoglobin-catalyzed fluorometric method for the determination of glutathione

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Wang, Ruiqiang; Tang, Lin; Li, Hua; Wang, Yi; Gou, Rong; Guo, Yuanyuan; Fang, Yudong; Chen, Fengmei

2016-01-01

A new spectrofluorometric method for the determination of glutathione based on the reaction catalyzed by hemoglobin was reported. The reaction product gave a highly fluorescent intensity with the excitation and emission wavelengths of 320.0 nm and 413.0 nm, respectively. The optimum experimental conditions were investigated. Results showed that low concentration glutathione enhanced the fluorescence intensity significantly. The line ranges were 1.0 × 10-6-1.0 × 10-5 mol L-1 of glutathione and 6.0 × 10-10 mol L-1-1.0 × 10-8 mol L-1, respectively. The detection limit was calculated to be 1.1 × 10-11 mol L-1. The recovery test by the standard addition method gave values in the range of 90.78%-102.20%. This method was used for the determination of glutathione in synthetic and real samples with satisfactory results.

Extraction of glutathione from EFB fermentation waste using methanol with sonication process

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Muryanto, Muryanto; Alvin, Nurdin, Muhammad; Hanifah, Ummu; Sudiyani, Yanni

2017-11-01

Glutathione is important compound on the human body. Glutathione have a widely use at pharmacy and cosmetics as detoxification, skin whitening agent, antioxidant and many other. This study aims to obtain glutathione from Saccharomyces cerevisiae in fermentation waste of second generation bioethanol. The remaining yeast in the empty fruit bunch (EFB) fermentation was separated from the fermentation solution use centrifugation process and then extracted using a methanol-water solution. The extraction process was done by maceration which was assisted by sonication process. Solvent concentration and time of sonication were varied to see its effect on glutathione concentration. The concentration of glutathione from the extraction process was analyzed using alloxan method with UV-Vis spectrophotometer. The results show that the highest glutathione concentration was approximately 1.32 g/L obtained with methanol solvent at 90 minutes of maceration following with 15 minutes sonication.

Albumin-gold-glutathione is a probable auranofin metabolite

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Shaw, C.F. III; Coffer, M.; Isab, A.A.

1989-01-01

The newly licensed gold drug, auranofin ((2,3,4,6-tetra-O-acetyl-β-1-D-gluco-pyranosato-S-)triethylphoshine-gold(I)) crosses cell membranes and enters cells which are inaccessible to parenteral gold drugs. In vivo, the triethylphosphine ligand and gold of auranofin, but not the thio-sugar moiety, accumulate in and subsequently efflux from red blood cells (RBCs). Extracellular albumin increases in the extent of gold efflux and acts as a gold binding site. The rate of efflux is first-order in RBC gold concentration. Studies using RBCs in which labelled [ 14 C]-glutathione is generated in situ incorporation of [ 14 C]- glycine demonstrate that glutathione also effluxes from the RBCs and forms a gold-glutathione-albumin complex. This may be the immunopharmacologically active complex

Expression of Glutathione Peroxidase and Glutathione Reductase and Level of Free Radical Processes under Toxic Hepatitis in Rats

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Igor Y. Iskusnykh

2013-01-01

Full Text Available Correlation between intensity of free radical processes estimated by biochemiluminesce parameters, content of lipoperoxidation products, and changes of glutathione peroxidase (GP, EC 1.11.1.9 and glutathione reductase (GR, EC 1.6.4.2 activities at rats liver injury, after 12, 36, 70, 96, 110, and 125 hours & tetrachloromethane administration have been investigated. The histological examination of the liver sections of rats showed that prominent hepatocytes with marked vacuolisation and inflammatory cells which were arranged around the necrotic tissue are more at 96 h after exposure to CCl4. Moreover maximum increase in GR and GP activities, 2.1 and 2.5 times, respectively, was observed at 96 h after exposure to CCl4, what coincided with the maximum of free radical oxidation processes. Using a combination of reverse transcription and real-time polymerase chain reaction, expression of the glutathione peroxidase and glutathione reductase genes (Gpx1 and Gsr was analyzed by the determination of their respective mRNAs in the rat liver tissue under toxic hepatitis conditions. The analyses of Gpx1 and Gsr expression revealed that the transcript levels increased in 2.5- and 3.0-folds, respectively. Western blot analysis revealed that the amounts of hepatic Gpx1 and Gsr proteins increased considerably after CCl4 administration. It can be proposed that the overexpression of these enzymes could be a mechanism of enhancement of hepatocytes tolerance to oxidative stress.

Novel substrate specificity of glutathione synthesis enzymes from Streptococcus agalactiae and Clostridium acetobutylicum

International Nuclear Information System (INIS)

Kino, Kuniki; Kuratsu, Shoko; Noguchi, Atsushi; Kokubo, Masahiro; Nakazawa, Yuji; Arai, Toshinobu; Yagasaki, Makoto; Kirimura, Kohtaro

2007-01-01

Glutathione (GSH) is synthesized by γ-glutamylcysteine synthetase (γ-GCS) and glutathione synthetase (GS) in living organisms. Recently, bifunctional fusion protein, termed γ-GCS-GS catalyzing both γ-GCS and GS reactions from gram-positive firmicutes Streptococcus agalactiae, has been reported. We revealed that in the γ-GCS activity, S. agalactiae γ-GCS-GS had different substrate specificities from those of Escherichia coli γ-GCS. Furthermore, S. agalactiae γ-GCS-GS synthesized several kinds of γ-glutamyltripeptide, γ-Glu-X aa -Gly, from free three amino acids. In Clostridium acetobutylicum, the genes encoding γ-GCS and putative GS were found to be immediately adjacent by BLAST search, and had amino acid sequence homology with S. agalactiae γ-GCS-GS, respectively. We confirmed that the proteins expressed from each gene showed γ-GCS and GS activity, respectively. C. acetobutylicum GS had broad substrate specificities and synthesized several kinds of γ-glutamyltripeptide, γ-Glu-Cys-X aa . Whereas the substrate specificities of γ-GCS domain protein and GS domain protein of S. agalactiae γ-GCS-GS were the same as those of S. agalactiae γ-GCS-GS

Shikonin protects dopaminergic cell line PC12 against 6-hydroxydopamine-mediated neurotoxicity via both glutathione-dependent and independent pathways and by inhibiting apoptosis.

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Esmaeilzadeh, Emran; Gardaneh, Mossa; Gharib, Ehsan; Sabouni, Farzaneh

2013-08-01

We have investigated the mechanism of shikonin function on protection of dopaminergic neurons against 6-OHDA-induced neurotoxicity. Treatment of rat pheochromocytoma cell line PC12 by serial dilutions of shikonin determined 10 μM of the compound as its optimum concentration for protection saving nearly 70 % of the cells against toxicity. Reverse transcription-PCR analysis of shikonin-treated cells showed threefold increase in mRNA levels of glutathione peroxidase-1 (GPX-1) as a representative component of the intracellular anti-oxidant defense system. To elucidate shikonin-GPX1 relationships and maximize protection, we transduced PC12 cells using recombinant lentivirus vectors that harbored GPX-1 coding sequence. This change upregulated GPX-1 expression, increased peroxidase activity and made neuronal cells resistant to 6-OHDA-mediated toxicity. More importantly, addition of shikonin to GPX1-overexpressing PC12 cells augmented GPX-1 protein content by eightfold leading to fivefold increase of enzymatic activity, 91 % cell survival against neurotoxicity and concomitant increases in intracellular glutathione (GSH) levels. Depletion of intracellular GSH rendered all cell groups highly susceptible to toxicity; however, shikonin was capable of partially saving them. Subsequently, GSH-independent superoxide dismutase mRNA was found upregulated by shikonin. As signs of apoptosis inhibition, the compound upregulated Bcl-2, downregulated Bax, and prevented cell nuclei from undergoing morphological changes typical of apoptosis. Also, a co-staining method demonstrated GPX-1 overexpression significantly increases the percent of live cells that is maximized by shikonin treatment. Our data indicate that shikonin as an antioxidant compound protects dopaminergic neurons against 6-OHDA toxicity and enhances their survival via both glutathione-dependent and direct anti-apoptotic pathways.

Antioxidant role of glutathione S-transferases: 4-Hydroxynonenal, a key molecule in stress-mediated signaling.

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Singhal, Sharad S; Singh, Sharda P; Singhal, Preeti; Horne, David; Singhal, Jyotsana; Awasthi, Sanjay

2015-12-15

4-Hydroxy-2-trans-nonenal (4HNE), one of the major end products of lipid peroxidation (LPO), has been shown to induce apoptosis in a variety of cell lines. It appears to modulate signaling processes in more than one way because it has been suggested to have a role in signaling for differentiation and proliferation. It has been known that glutathione S-transferases (GSTs) can reduce lipid hydroperoxides through their Se-independent glutathione-peroxidase activity and that these enzymes can also detoxify LPO end-products such as 4HNE. Available evidence from earlier studies together with results of recent studies in our laboratories strongly suggests that LPO products, particularly hydroperoxides and 4HNE, are involved in the mechanisms of stress-mediated signaling and that it can be modulated by the alpha-class GSTs through the regulation of the intracellular concentrations of 4HNE. We demonstrate that 4HNE induced apoptosis in various cell lines is accompanied with c-Jun-N-terminal kinase (JNK) and caspase-3 activation. Cells exposed to mild, transient heat or oxidative stress acquire the capacity to exclude intracellular 4HNE at a faster rate by inducing GSTA4-4 which conjugates 4HNE to glutathione (GSH), and RLIP76 which mediates the ATP-dependent transport of the GSH-conjugate of 4HNE (GS-HNE). The balance between formation and exclusion promotes different cellular processes - higher concentrations of 4HNE promote apoptosis; whereas, lower concentrations promote proliferation. In this article, we provide a brief summary of the cellular effects of 4HNE, followed by a review of its GST-catalyzed detoxification, with an emphasis on the structural attributes that play an important role in the interactions with alpha-class GSTA4-4. Taken together, 4HNE is a key signaling molecule and that GSTs being determinants of its intracellular concentrations, can regulate stress-mediated signaling, are reviewed in this article. Copyright © 2015 Elsevier Inc. All rights

Protection of HepG2 cells against acrolein toxicity by 2-cyano-3,12-dioxooleana-1,9-dien-28-imidazolide via glutathione-mediated mechanism.

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Shah, Halley; Speen, Adam M; Saunders, Christina; Brooke, Elizabeth A S; Nallasamy, Palanisamy; Zhu, Hong; Li, Y Robert; Jia, Zhenquan

2015-10-01

Acrolein is an environmental toxicant, mainly found in smoke released from incomplete combustion of organic matter. Several studies showed that exposure to acrolein can lead to liver damage. The mechanisms involved in acrolein-induced hepatocellular toxicity, however, are not completely understood. This study examined the cytotoxic mechanisms of acrolein on HepG2 cells. Acrolein at pathophysiological concentrations was shown to cause apoptotic cell death and an increase in levels of protein carbonyl and thiobarbituric acid reactive acid substances. Acrolein also rapidly depleted intracellular glutathione (GSH), GSH-linked glutathione-S-transferases, and aldose reductase, three critical cellular defenses that detoxify reactive aldehydes. Results further showed that depletion of cellular GSH by acrolein preceded the loss of cell viability. To further determine the role of cellular GSH in acrolein-mediated cytotoxicity, buthionine sulfoximine (BSO) was used to inhibit cellular GSH biosynthesis. It was observed that depletion of cellular GSH by BSO led to a marked potentiation of acrolein-mediated cytotoxicity in HepG2 cells. To further assess the contribution of these events to acrolein-induced cytotoxicity, triterpenoid compound 2-cyano-3,12-dioxooleana-1,9-dien-28-imidazolide (CDDO-Im) was used for induction of GSH. Induction of GSH by CDDO-Im afforded cytoprotection against acrolein toxicity in HepG2 cells. Furthermore, BSO significantly inhibited CDDO-Im-mediated induction in cellular GSH levels and also reversed cytoprotective effects of CDDO-Im in HepG2 cells. These results suggest that GSH is a predominant mechanism underlying acrolein-induced cytotoxicity as well as CDDO-Im-mediated cytoprotection. This study may provide understanding on the molecular action of acrolein which may be important to develop novel strategies for the prevention of acrolein-mediated toxicity. © 2014 by the Society for Experimental Biology and Medicine.

Over-expression of bacterial gamma-glutamylcysteine synthetase (GSH1) in plastids affects photosynthesis, growth and sulphur metabolism in poplar (Populus tremula x Populus alba) dependent on the resulting gamma-glutamylcysteine and glutathione levels.

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Herschbach, Cornelia; Rizzini, Luca; Mult, Susanne; Hartmann, Tanja; Busch, Florian; Peuke, Andreas D; Kopriva, Stanislav; Ensminger, Ingo

2010-07-01

We compared three transgenic poplar lines over-expressing the bacterial gamma-glutamylcysteine synthetase (GSH1) targeted to plastids. Lines Lggs6 and Lggs12 have two copies, while line Lggs20 has three copies of the transgene. The three lines differ in their expression levels of the transgene and in the accumulation of gamma-glutamylcysteine (gamma-EC) and glutathione (GSH) in leaves, roots and phloem exudates. The lowest transgene expression level was observed in line Lggs6 which showed an increased growth, an enhanced rate of photosynthesis and a decreased excitation pressure (1-qP). The latter typically represents a lower reduction state of the plastoquinone pool, and thereby facilitates electron flow along the electron transport chain. Line Lggs12 showed the highest transgene expression level, highest gamma-EC accumulation in leaves and highest GSH enrichment in phloem exudates and roots. This line also exhibited a reduced growth, and after a prolonged growth of 4.5 months, symptoms of leaf injury. Decreased maximum quantum yield (F(v)/F(m)) indicated down-regulation of photosystem II reaction centre (PSII RC), which correlates with decreased PSII RC protein D1 (PsbA) and diminished light-harvesting complex (Lhcb1). Potential effects of changes in chloroplastic and cytosolic GSH contents on photosynthesis, growth and the whole-plant sulphur nutrition are discussed for each line.

Novel function of glutathione transferase in rat liver mitochondrial membrane: Role for cytochrome c release from mitochondria

International Nuclear Information System (INIS)

Lee, Kang Kwang; Shimoji, Manami; Hossain, Quazi Sohel; Sunakawa, Hajime; Aniya, Yoko

2008-01-01

Microsomal glutathione transferase (MGST1) is activated by oxidative stress. Although MGST1 is found in mitochondrial membranes (mtMGST1), there is no information about the oxidative activation of mtMGST1. In the present study, we aimed to determine whether mtMGST1 also undergoes activation and about its function. When rats were treated with galactosamine/lipopolysaccharide (GalN/LPS), mtMGST1 activity was significantly increased, and the increased activity was reduced by the disulfide reducing agent dithiothreitol. In mitochondria from GalN/LPS-treated rats, disulfide-linked mtMGST1 dimer and mixed protein glutathione disulfides (glutathionylation) were detected. In addition, cytochrome c release from mitochondria isolated from GalN/LPS-treated rats was observed, and the release was inhibited by anti-MGST1 antibodies. Incubation of mitochondria from control rats with diamide and diamide plus GSH in vitro resulted in dimer- and mixed disulfide bond-mediated activation of mtMGST1, respectively. The activation of mtMGST1 by diamide plus GSH caused cytochrome c release from the mitochondria, and the release was prevented by treatment with anti-MGST1 antibodies. In addition, diamide plus GSH treatment caused mitochondrial swelling accompanied by cytochrome c release, which was inhibited by cyclosporin A (CsA) and bongkrekic acid (BKA), inhibitors of the mitochondrial permeability transition (MPT) pore. Furthermore, mtMGST1 activity was also inhibited by CsA and BKA. These results indicate that mtMGST1 is activated through mixed disulfide bond formation that contributes to cytochrome c release from mitochondria through the MPT pore

Coupling gold nanoparticles to silica nanoparticles through disulfide bonds for glutathione detection

International Nuclear Information System (INIS)

Shi Yupeng; Zhang Heng; Zhang Zhaomin; Yi Changqing; Yue Zhenfeng; Teng, Kar-Seng; Li Meijin; Yang Mengsu

2013-01-01

Advances in the controlled assembly of nanoscale building blocks have resulted in functional devices which can find applications in electronics, biomedical imaging, drug delivery etc. In this study, novel covalent nanohybrid materials based upon [Ru(bpy) 3 ] 2+ -doped silica nanoparticles (SiNPs) and gold nanoparticles (AuNPs), which could be conditioned as OFF–ON probes for glutathione (GSH) detection, were designed and assembled in sequence, with the disulfide bonds as the bridging elements. The structural and optical properties of the nanohybrid architectures were characterized using transmission electron microscopy, UV–vis spectroscopy and fluorescence spectroscopy, respectively. Zeta potential measurements, x-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were employed to monitor the reaction processes of the SiNPs–S–S–COOH and SiNPs–S–S–AuNPs synthesis. It was found that the covalent nanohybrid architectures were fluorescently dark (OFF state), indicating that SiNPs were effectively quenched by AuNPs. The fluorescence of the OFF–ON probe was resumed (ON state) when the bridge of the disulfide bond was cleaved by reducing reagents such as GSH. This work provides a new platform and strategy for GSH detection using covalent nanohybrid materials. (paper)

Effects of N-acetyl-cysteine treatment on glutathione depletion and a short-term spatial memory deficit in 2-cyclohexene-1-one-treated rats.

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Choy, Kwok Ho Christopher; Dean, Olivia; Berk, Michael; Bush, Ashley I; van den Buuse, Maarten

2010-12-15

Glutathione (GSH) is the primary antioxidant in the body and is present in high levels in the brain. Levels of GSH and other antioxidants are significantly altered in major psychiatric illnesses, such as schizophrenia. Recent clinical trials have demonstrated that chronic treatment with N-acetyl-l-cysteine (NAC), a GSH precursor, improved symptoms in individuals with this illness. We previously showed in rats and mice that depletion of GSH by treatment with 2-cyclohexene-1-one (CHX) induced short-term spatial memory deficits in the Y-maze test. The aim of present study was to characterise the effect of NAC in this CHX-induced glutathione depletion model. Consistent with our previous studies, CHX treatment induced approximately 50% reduction of GSH levels in striatum, hippocampus and frontal cortex tissue. GSH depletion was significantly rescued by either 1.2 g/kg or 1.6 g/kg of NAC administration, with a full recovery observed in the frontal cortex after the high dose of NAC. CHX treatment also induced a disruption in short-term spatial recognition memory in Y-maze test, as measured by the duration of time spent in the novel arm. This disruption was reversed by treatment with 1.6 g/kg of NAC. In conclusion, this study suggests that rescue of depleted levels of GSH in the brain restores cognitive deficits, as measured by the Y-maze. These effects appear to be dose-dependent and region-specific. These results may be relevant to the understanding and management of the cognitive symptoms of schizophrenia and bipolar disorder. Copyright © 2010 Elsevier B.V. All rights reserved.

Studies on the effects of lead toxicity on glutathione metabolism in the chick

International Nuclear Information System (INIS)

McGowan, C.

1985-01-01

Studies were performed to investigate certain aspects of lead toxicity in the chick. In the first study, the mechanism of the Pb-induced changes in glutathione (GSH) metabolism was examined by comparing changes in organ non-protein thiol concentrations during the administration of Pb by intraperitoneal injection (acute) or in the diet (chronic). The synthesis of GSH in the liver was increased by both acute and chronic Pb administration when evaluated in terms of the rate of incorporation of [I 14 C]-glycine into hepatic GSH. Total nonprotein sulfhydryl (NPSH) concentrations were also increased by both acute and chronic Pb. However, that portion of NPSH which is GSH was increased only by prolonged (chronic) exposure to Pb. The administration of buthionine sulfoximine (BSO), an inhibitor of GSH synthesis, decreased hepatic HPDH and GSH concentrations both in the presence and absence of injected Pb and inhibited the effects of dietary Pb on hepatic NPSH and GSH concentrations. The data suggested an immediate release of NPSH compounds into blood plasma following acute PB injection. Thus, the interorgan translocation system for GSH may be important in acute Pb intoxication in that it facilitates an immediate response to maintain cellular GSH levels being depleted by detoxification reactions by increasing the rate of GSH turnover. The antagonistic relationship between Pb and Se was investigated in terms of chick body weight gain and changes in organ non-protein thiol concentrated when administered with diets containing deficient adequate, and excess amounts of Se. Growth depression by 2000 ppm dietary Pb was observed with diets that were either deficient or adequate in dietary Se

Role of glutathione in tolerance to arsenite in Salvinia molesta, an aquatic fern

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Adinan Alves da Silva

2017-09-01

Full Text Available ABSTRACT In many plant species, tolerance to toxic metals is highly dependent on glutathione, an essential metabolite for cellular detoxification. We evaluated the responses of glutathione metabolism to arsenite (AsIII in Salvinia molesta, an aquatic fern that has unexplored phytoremediation potential. Plants were exposed to different AsIII concentrations in nutrient solution for 24 h. AsIII caused cell membrane damage to submerged leaves, indicating oxidative stress. There was an increase in the glutathione content and ϒ-glutamylcysteine synthetase enzyme activity in the submerged and floating leaves. The glutathione peroxidase and glutathione sulfotransferase enzymes also showed increased activity in both plant parts, whereas glutathione reductase only showed increased activity in the submerged leaves. These findings suggest an important role for glutathione in the protection of S. molesta against the toxic effects of AsIII, with more effective tolerance responses in the floating leaves.

Implications of Glutathione Levels in the Plasmodium berghei Response to Chloroquine and Artemisinin.

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Joel Vega-Rodríguez

Full Text Available Malaria is one of the most devastating parasitic diseases worldwide. Plasmodium drug resistance remains a major challenge to malaria control and has led to the re-emergence of the disease. Chloroquine (CQ and artemisinin (ART are thought to exert their anti-malarial activity inducing cytotoxicity in the parasite by blocking heme degradation (for CQ and increasing oxidative stress. Besides the contribution of the CQ resistance transporter (PfCRT and the multidrug resistant gene (pfmdr, CQ resistance has also been associated with increased parasite glutathione (GSH levels. ART resistance was recently shown to be associated with mutations in the K13-propeller protein. To analyze the role of GSH levels in CQ and ART resistance, we generated transgenic Plasmodium berghei parasites either deficient in or overexpressing the gamma-glutamylcysteine synthetase gene (pbggcs encoding the rate-limiting enzyme in GSH biosynthesis. These lines produce either lower (pbggcs-ko or higher (pbggcs-oe levels of GSH than wild type parasites. In addition, GSH levels were determined in P. berghei parasites resistant to CQ and mefloquine (MQ. Increased GSH levels were detected in both, CQ and MQ resistant parasites, when compared to the parental sensitive clone. Sensitivity to CQ and ART remained unaltered in both pgggcs-ko and pbggcs-oe parasites when tested in a 4 days drug suppressive assay. However, recrudescence assays after the parasites have been exposed to a sub-lethal dose of ART showed that parasites with low levels of GSH are more sensitive to ART treatment. These results suggest that GSH levels influence Plasmodium berghei response to ART treatment.

Effects of glutathione depletion by buthionine sulfoximine on radiosensitization by oxygen and misonidazole in vitro

International Nuclear Information System (INIS)

Shrieve, D.C.; Denekamp, J.; Minchinton, A.I.

1985-01-01

Buthionine sulfoximine (BSO) has been used to deplete glutathione (GSH) in V79-379A cells in vitro, and the effect on the efficiency of oxygen and misonidazole (MISO) as radiosensitizers has been determined. Treatment with 50 or 500 μM BSO caused a rapid decline in GSH content to less than 5% of control values after 10 hr of exposure. Removal of BSO resulted in a rapid regeneration of GSH after 50 μM BSO, but little regeneration was observed over the subsequent 10-hr period after 500 μM. Cells irradiated in monolayer on glass had an oxygen enhancement ratio (OER) of 3.1. After 10-14 hr pretreatment with 50 μM BSO, washed cells were radiosensitized by GSH depletion at all oxygen tensions tested. The OER was reduced to 2.6, due to greater radiosensitization of hypoxic cells than aerated ones by GSH depletion. In similar experiments performed with MISO, an enhancement ratio of 2.0 could be achieved with 0.2 mM MISO in anoxic BSO-pretreated cells, compared to 2.7 mM MISO in non-BSO-treated cells. These apparent increases in radiosensitizer efficiency in GSH-depleted cells could be explained on the basis of radiosensitization of hypoxic cells by GSH depletion alone. These results are consistent with hypoxic cell radiosensitization by GSH depletion and by MISO or oxygen acting by separate mechanisms

Uranyl complexes of glutathione

Energy Technology Data Exchange (ETDEWEB)

Marzotto, A [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi

1977-01-01

Dioxouranium(VI) complexes of the tripeptide glutathione having different molar ratios were prepared and studied by IR, PMR, electronic absorption and circular dichroism spectra. The results indicate that coordination occurs at the carboxylato groups, acting as monodentate ligands, whereas no significant interaction with the amino and sulfhydrylic groups takes place.

Aqueous synthesis of highly luminescent glutathione-capped Mn{sup 2+}-doped ZnS quantum dots

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Kolmykov, Oleksii [Université de Lorraine, Laboratoire Réactions et Génie des Procédés (LRGP), UMR 7274, CNRS, 1 rue Grandville, BP 20451, 54001 Nancy Cedex (France); Coulon, Joël [Université de Lorraine, Laboratoire de Chimie Physique et Microbiologie pour l' Environnement (LCPME), UMR 7564, CNRS, Faculté de Pharmacie, 5 rue Albert Lebrun, 54000 Nancy (France); Lalevée, Jacques [Institut de Science des Matériaux de Mulhouse (IS2M), UMR 7361, CNRS, 15 rue Jean Starcky, 68093 Mulhouse (France); Alem, Halima; Medjahdi, Ghouti [Université de Lorraine, Institut Jean Lamour (IJL), UMR 7198, CNRS, BP 70239, 54506 Vandoeuvre-lès-Nancy Cedex (France); Schneider, Raphaël, E-mail: raphael.schneider@univ-lorraine.fr [Université de Lorraine, Laboratoire Réactions et Génie des Procédés (LRGP), UMR 7274, CNRS, 1 rue Grandville, BP 20451, 54001 Nancy Cedex (France)

2014-11-01

In this paper, an aqueous-based route has been developed to prepare highly luminescent glutathione (GSH)-capped Mn-doped ZnS quantum dots (QDs). The dots obtained have an average diameter of 4.3 nm and exhibit the Mn{sup 2+}-related orange luminescence with very low surface defect density. The highest photoluminescence was observed for a Mn{sup 2+} to Zn{sup 2+} molar ratio of 3%. Consecutive overcoating of the Mn:ZnS@GSH QDs by a ZnS shell was done, and the core/shell structured QDs exhibit a PL quantum yield of 23%. Transmission electron microscopy, X-ray powder diffraction, electron spin resonance, X-ray photoelectron spectroscopy, UV–visible spectroscopy and spectrofluorometry have been used to characterize the crystal structure, the doping status, and the optical properties of the doped-QDs. Our systematic investigation shows that Mn:ZnS/ZnS@GSH QDs are highly promising fluorescent labels in biological applications.

Improved stress tolerance and productivity in transgenic rice plants constitutively expressing the Oryza sativa glutathione synthetase OsGS under paddy field conditions.

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Park, Seong-Im; Kim, Young-Saeng; Kim, Jin-Ju; Mok, Ji-Eun; Kim, Yul-Ho; Park, Hyang-Mi; Kim, Il-Sup; Yoon, Ho-Sung

2017-08-01

Reactive oxygen species, which increase under various environmental stresses, have deleterious effects on plants. An important antioxidant, glutathione, is used to detoxify reactive oxygen species in plant cells and is mainly produced by two enzymes: gamma-glutamylcysteine synthetase (γ-ECS) and glutathione synthetase (GS). To evaluate the functional roles of the glutathione synthetase gene (OsGS) in rice, we generated four independent transgenic rice plants (TG1-TG4) that overexpressed OsGS under the control of the constitutively expressed OsCc1 promoter. When grown under natural paddy field conditions, the TG rice plants exhibited greater growth development, higher chlorophyll content, and higher GSH/GSSH ratios than control wild-type (WT) rice plants. Subsequently, the TG rice plants enhanced redox homeostasis by preventing hydroperoxide-mediated membrane damage, which improved their adaptation to environmental stresses. As a result, TG rice plants improved rice grain yield and total biomass following increases in panicle number and number of spikelets per panicle, despite differences in climate during the cultivation periods of 2014 and 2015. Overall, our results indicate that OsGS overexpression improved redox homeostasis by enhancing the glutathione pool, which resulted in greater tolerance to environmental stresses in the paddy fields. Copyright © 2017. Published by Elsevier GmbH.

Reduced glutathione as a persistence indicator of alien plants of the Amelancheir family

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L. G. Dolgova

2009-04-01

Full Text Available It was proved that glutathione is an important indicator of the vegetation condition and persistence. According to the amount of glutathione the studied mespilus species are adapted to the environmental conditions. Increase of the glutathione amount is caused by some abiotic factors, e.g. temperature. Some differences of the glutathione content may be explained by the plants species patterns.

Mathematical modeling of glutathione status in type 2 diabetics with vitamin B12 deficiency

Directory of Open Access Journals (Sweden)

Varun eKaramshetty

2016-03-01

Full Text Available Deficiencies in vitamin B12 and glutathione (GSH are associated with anumber of diseases including type 2 diabetes mellitus. We tested newly diag-nosed Indian diabetic patients for correlation between their vitamin B12 andGSH, and found it to be weak. Here we seek to examine the theoreticaldependence of GSH on vitamin B12 with a mathematical model of 1-carbonmetabolism due to Reed and co-workers. We study the methionine cycleof the Reed-Nijhout model by developing a simple ‘stylized model’ that cap-tures its essential topology and whose kinetics are analytically tractable. Theanalysis shows – somewhat counter-intuitively – that the flux responsible forthe homeostasis of homocysteine is, in fact, peripheral to the methioninecycle. Elevation of homocysteine arises from reduced activity of methioninesynthase, a vitamin B12-dependent enzyme, however, this does not increaseGSH biosynthesis. The model suggests that the lack of vitamin B12–GSHcorrelation is explained by suppression of activity in the trans-sulfurationpathway that limits the synthesis of cysteine and GSH from homocysteine.We hypothesize this ‘cysteine-block’ is an essential consequence of vitaminB12 deficiency. It can be clinically relevant to appreciate that these secondaryeffects of vitamin B12 deficiency could be central to its pathophysiology.

Glutathione level and its relation to radiation therapy in patients with cancer of uterine cervix

International Nuclear Information System (INIS)

Mukundan, H.; Bahadur, A.K.; Kumar, A.; Sardana, S.; Naik, S.L.D.; Ray, A.; Sharma, B.K.

1999-01-01

Glutathione functions as an important antioxidant in the destruction of hydrogen peroxide and lipid peroxides by providing substrate for the glutathione peroxidase and also promotes the ascorbic acid. Glutathione plays a vital role in detoxification of xenobiotics, carcinogens, free radicals and maintenance of immune functions. The study was aimed to determine plasma glutathione as well as erythrocyte glutathione and glutathione peroxidase in patients with invasive cervical carcinoma (n=30) before initiation and after completion of radiotherapy and subsequently, at the time of first three monthly follow-up visit. The levels of plasma glutathione, erythrocyte glutathione and glutathione peroxidase activity were found to be lower in all cervical cancer patients as compared to age matched normal control women. The study indicates a change in antioxidant status in relation with the glutathione system among patients with invasive carcinoma of the uterine cervix. This study also demonstrates the effect of radiation therapy on this antioxidant system. (author)

Effects of imidacloprid on detoxifying enzyme glutathione S-transferase on Folsomia candida (Collembola).

Science.gov (United States)

Sillapawattana, Panwad; Schäffer, Andreas

2017-04-01

Chemical analyses of the environment can document contamination by various xenobiotics, but it is also important to understand the effect of pollutants on living organisms. Thus, in the present work, we investigated the effect of the pesticide imidacloprid on the detoxifying enzyme glutathione S-transferase (GST) from Folsomia candida (Collembola), a standard test organism for estimating the effects of pesticides and environmental pollutants on non-target soil arthropods. Test animals were treated with different concentrations of imidacloprid for 48 h. Changes in steady-state levels of GST messenger RNA (mRNA) and GST enzyme activity were investigated. Extracted proteins were separated according to their sizes by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the resolved protein bands were detected by silver staining. The size of the glutathione (GSH) pool in Collembola was also determined. A predicted protein sequence of putative GSTs was identified with animals from control group. A 3-fold up-regulation of GST steady-state mRNA levels was detected in the samples treated with 5.0 mg L -1 imidacloprid compared to the control, while a 2.5- and 2.0- fold up-regulation was found in organisms treated with 2.5 and 7.5 mg L -1 imidacloprid, respectively. GST activity increased with increasing imidacloprid amounts from an initial activity of 0.11 μmol min -1  mg -1 protein in the control group up to 0.25 μmol min -1  mg -1 protein in the sample treated with the 5.0 mg L -1 of pesticide. By contrast, the total amount of GSH decreased with increasing imidacloprid concentration. The results suggest that the alteration of GST activity, steady-state level of GST mRNA, and GSH level may be involved in the response of F. candida to the exposure of imidacloprid and can be used as biomarkers to monitor the toxic effects of imidacloprid and other environmental pollutants on Collembola.

Effect of acrolein and glutathione depleting agents on thioredoxin

International Nuclear Information System (INIS)

Yang Xianmei; Wu Xuli; Choi, Young Eun; Kern, Julie C.; Kehrer, James P.

2004-01-01

Acrolein is a widespread environmental pollutant that reacts rapidly with nucleophiles, especially cellular thiols. In addition to glutathione (GSH), thioredoxin (Trx) and thioredoxin reductase (TR) contain thiol groups and may react with electrophiles. In the present study, A549 cells treated with 5-25 μM acrolein for 30 min lost cellular Trx activity in a dose-dependent fashion. Over 90% of Trx activity was lost at concentrations of 25 μM or greater. In contrast, Trx protein content, as assessed by western blotting, was not altered immediately after the 30 min acrolein treatment. Both Trx activity and protein levels increased 4 h after the acrolein treatment. However, Trx activity remained below control levels at 24 h. A similar dose-response relationship was seen with TR in A549 cells exposed to acrolein. There was, however, a rapid recovery of TR activity such that it attained normal levels by 4 h after doses ≤75 μM acrolein. Diethyl maleate (DEM), a common but not highly specific, agent used to deplete GSH, also inactivated Trx. A 2 h exposure of A549 cells to 1 mM DEM depleted cellular GSH by ∼50% and diminished Trx activity by over 67%. Lower DEM doses (0.125 mM and 0.25 mM) for 1 h had no significant effect on GSH but significantly decreased Trx activity 12 and 23%, respectively. Similar to immediately after acrolein exposure, DEM did not affect Trx protein levels. A Trx-1-GFP fusion protein was transfected into A549 cells. While the fusion protein was expressed, the Trx component was inactive by the insulin reducing assay. In summary, Trx and TR are inactivated by acrolein. In addition, the GSH depleting agent DEM inactivates Trx somewhat more effectively than it depletes GSH. The Trx-1-GFP fusion protein, while readily expressed, appears to have little or no activity, perhaps because the small size of Trx-1 (12 kDa) is affected by the larger GFP

l-glutamine and l-alanine supplementation increase glutamine-glutathione axis and muscle HSP-27 in rats trained using a progressive high-intensity resistance exercise.

Science.gov (United States)

Leite, Jaqueline Santos Moreira; Raizel, Raquel; Hypólito, Thaís Menezes; Rosa, Thiago Dos Santos; Cruzat, Vinicius Fernandes; Tirapegui, Julio

2016-08-01

In this study we investigated the chronic effects of oral l-glutamine and l-alanine supplementation, either in their free or dipeptide form, on glutamine-glutathione (GLN-GSH) axis and cytoprotection mediated by HSP-27 in rats submitted to resistance exercise (RE). Forty Wistar rats were distributed into 5 groups: sedentary; trained (CTRL); and trained supplemented with l-alanyl-l-glutamine, l-glutamine and l-alanine in their free form (GLN+ALA), or free l-alanine (ALA). All trained animals were submitted to a 6-week ladder-climbing protocol. Supplementations were offered in a 4% drinking water solution for 21 days prior to euthanasia. Plasma glutamine, creatine kinase (CK), myoglobin (MYO), and erythrocyte concentration of reduced GSH and glutathione disulfide (GSSG) were measured. In tibialis anterior skeletal muscle, GLN-GSH axis, thiobarbituric acid reactive substances (TBARS), and the expression of heat shock factor 1 (HSF-1), 27-kDa heat shock protein (HSP-27), and glutamine synthetase were determined. In CRTL animals, high-intensity RE reduced muscle glutamine levels and increased GSSG/GSH rate and TBARS, as well as augmented plasma CK and MYO levels. Conversely, l-glutamine-supplemented animals showed an increase in plasma and muscle levels of glutamine, with a reduction in GSSG/GSH rate, TBARS, and CK. Free l-alanine administration increased plasma glutamine concentration and lowered muscle TBARS. HSF-1 and HSP-27 were high in all supplemented groups when compared with CTRL (p alanine, in both a free or dipeptide form, improve the GLN-GSH axis and promote cytoprotective effects in rats submitted to high-intensity RE training.

The glutathione synthesis inhibitor buthionine sulfoximine synergistically enhanced melphalan activity against preclinical models of multiple myeloma

International Nuclear Information System (INIS)

Tagde, A; Singh, H; Kang, M H; Reynolds, C P

2014-01-01

Melphalan (L-PAM) has been an integral part of multiple myeloma (MM) treatment as a conditioning regimen before stem cell transplant (SCT). After initial response, most treated patients experience relapse with an aggressive phenotype. Increased glutathione (GSH) in MM may mediate resistance to L-PAM. We demonstrated that the GSH synthesis inhibitor buthionine sulfoximine (BSO) synergistically enhanced L-PAM activity (inducing 2–4 logs of cell kill) against nine MM cell lines (also in the presence of marrow stroma or cytokines) and in seven primary MM samples (combination indices <1.0). In MM cell lines, BSO significantly (P<0.05) depleted GSH, increased L-PAM-induced single-strand DNA breaks, mitochondrial depolarization, caspase cleavage and apoptosis. L-PAM depleted GSH, but GSH rapidly recovered in a L-PAM-resistant MM cell line unless also treated with BSO. Treatment with N-acetylcysteine antagonized BSO+L-PAM cytotoxicity without increasing GSH. In human MM xenografted into beige-nude-xid mice, BSO significantly depleted MM intracellular GSH and significantly increased apoptosis compared with L-PAM alone. BSO+L-PAM achieved complete responses (CRs) in three MM xenograft models including maintained CRs >100 days, and significantly increased the median event-free survival relative to L-PAM alone. Combining BSO with L-PAM warrants clinical testing in advanced MM

Interactions of [alpha,beta]-unsaturated carbonyl compounds with the glutathione-related biotransformation system

NARCIS (Netherlands)

Iersel, van M.L.P.S.

1998-01-01

Introduction
Modulation of glutathione-related biotransformation steps may play a role in important phenomena as anticarcinogenicity and multidrug resistance. Glutathione-related biotransformation comprises three main aspects i.e. glutathione, the

Multiscale modelling approach combining a kinetic model of glutathione metabolism with PBPK models of paracetamol and the potential glutathione-depletion biomarkes ophthalmic acid and 5-oxoproline in humans and rats

NARCIS (Netherlands)

Geenen, S.; Yates, J.W.T.; Kenna, J.G.; Bois, F.Y.; Wilson, I.D.; Westerhoff, H.V.

2014-01-01

A key role of the antioxidant glutathione is detoxification of chemically reactive electrophilic drug metabolites within the liver. Therefore glutathione depletion can have severe toxic consequences. Ophthalmic acid and 5-oxoproline are metabolites involved in glutathione metabolism, which can be

Methyl vinyl ketone, a toxic ingredient in cigarette smoke extract, modifies glutathione in mouse melanoma cells.

Science.gov (United States)

Horiyama, Shizuyo; Takahashi, Yuta; Hatai, Mayuko; Honda, Chie; Suwa, Kiyoko; Ichikawa, Atsushi; Yoshikawa, Noriko; Nakamura, Kazuki; Kunitomo, Masaru; Date, Sachiko; Masujima, Tsutomu; Takayama, Mitsuo

2014-01-01

Cigarette smoke contains many harmful chemicals, which contribute to the pathogenesis of smoking-related diseases such as chronic obstructive pulmonary disease, cancer and cardiovascular disease. The cytotoxicity of cigarette smoke is well documented, but the definitive mechanism behind its toxicity remains unknown. Ingredients in cigarette smoke are known to deplete intracellular glutathione (GSH), the most abundant cellular thiol antioxidant, and to cause oxidative stress. In the present study, we investigated the mechanism of cigarette smoke extract (CSE)-induced cytotoxicity in B16-BL6 mouse melanoma (B16-BL6) cells using liquid chromatography-tandem mass spectrometry. CSE and ingredients in cigarette smoke, methyl vinyl ketone (MVK) and crotonaldehyde (CA), reduced cell viability in a concentration-dependent manner. Also, CSE and the ingredients (m/z 70, each) irreversibly reacted with GSH (m/z 308) to form GSH adducts (m/z 378) in cells and considerably decreased cellular GSH levels at concentrations that do not cause cell death. Mass spectral data showed that the major product formed in cells exposed to CSE was the GSH-MVK adduct via Michael-addition and was not the GSH-CA adduct. These results indicate that MVK included in CSE reacts with GSH in cells to form the GSH-MVK adduct, and thus a possible reason for CSE-induced cytotoxicity is a decrease in intracellular GSH levels.

Glutathione transferases are structural and functional outliers in the thioredoxin fold.

Science.gov (United States)

Atkinson, Holly J; Babbitt, Patricia C

2009-11-24

Glutathione transferases (GSTs) are ubiquitous scavengers of toxic compounds that fall, structurally and functionally, within the thioredoxin fold suprafamily. The fundamental catalytic capability of GSTs is catalysis of the nucleophilic addition or substitution of glutathione at electrophilic centers in a wide range of small electrophilic compounds. While specific GSTs have been studied in detail, little else is known about the structural and functional relationships between different groupings of GSTs. Through a global analysis of sequence and structural similarity, it was determined that variation in the binding of glutathione between the two major subgroups of cytosolic (soluble) GSTs results in a different mode of glutathione activation. Additionally, the convergent features of glutathione binding between cytosolic GSTs and mitochondrial GST kappa are described. The identification of these structural and functional themes helps to illuminate some of the fundamental contributions of the thioredoxin fold to catalysis in the GSTs and clarify how the thioredoxin fold can be modified to enable new functions.

Andrographolide suppresses preadipocytes proliferation through glutathione antioxidant systems abrogation.

Science.gov (United States)

Chen, Wei; Su, Hongming; Feng, Lina; Zheng, Xiaodong

2016-07-01

Oxidative stress is considered to play a profound role in lipid storage and whole-body energy homeostasis. Inhibition of preadipocytes proliferation by natural products is one of the strategies to prevent obesity. Andrographolide, a small molecule, has been reported to possess versatile bioactivities. However, molecular mechanism underlying the potential effect of andrographolide on preadipocytes proliferation remains obscure. In the present study, 3T3-L1 preadipocytes were employed to determine whether andrographolide could affect the proliferation of preadipocytes. Our results demonstrated andrographolide suppressed 3T3-L1 preadipocytes proliferation. The casual relationship analysis indicated that andrographolide (10 and 20μg/ml) appeared to exert the proliferation inhibitory effect through suppression of glutathione peroxidase 1 (GPX1) activity and depleting GSH by promoting its efflux in 3T3-L1 preadipocytes, which subsequently resulted in 2.06-2.41 fold increase in ROS accumulation. Excessive ROS eruption could account for oxidative damage to mitochondrial membranes as well as ultimately inhibition of cell proliferation. Taken together, our study reveals that suppression of GPX1 and GSH depletion by andrographolide seems to play a critical role in the inhibition of 3T3-L1 preadipocytes proliferation, which might have implication for obesity prevention and treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

Targeting of the Glutathione, Thioredoxin, and Nrf2 Antioxidant Systems in Head and Neck Cancer.

Science.gov (United States)

Roh, Jong-Lyel; Jang, Hyejin; Kim, Eun Hye; Shin, Daiha

2017-07-10

The glutathione (GSH), thioredoxin (Trx), and Nrf2 systems represent a major defense against reactive oxygen species (ROS), the cellular imbalance of which in cancer promotes growth and therapeutic resistance. This study investigated whether targeting the GSH, Trx, and Nrf2 antioxidant systems effectively eliminated head and neck cancer (HNC). At high concentrations, auranofin, but not buthionine sulfoximine (BSO) alone, decreased the viability of HNC, whereas even at low concentrations, auranofin plus BSO synergized to kill HNC cells. Dual silencing of the genes for GCLM and TrxR1 induced GSH depletion, Trx activity inhibition, and ROS accumulation, synergistically killing HNC cells. Inhibition of the GSH and Trx systems resulted in activation of the Nrf2-antioxidant response element (ARE) pathway, which may result in suboptimal GSH and Trx inhibition where HNC is resistant. Genetic inhibition of Nrf2 and/or HO-1 or trigonelline enhanced growth suppression, ROS accumulation, and cell death from GSH and Trx inhibition. The in vivo effects of GSH, Trx, and Nrf2 system inhibition were confirmed in a mouse HNC xenograft model by achieving growth inhibition >60% compared with those of control. Innovations: This study is the first to show that triple inhibition of GSH, Trx, and Nrf2 pathways could be an effective method to overcome the resistance of HNC. Inhibition of the Nrf2-ARE pathway in addition to dual inhibition of the GSH and Trx antioxidant systems can effectively eliminate resistant HNC. Antioxid. Redox Signal. 27, 106-114.

The pulmonary inflammatory response to multiwalled carbon nanotubes is influenced by gender and glutathione synthesis

Directory of Open Access Journals (Sweden)

Megan M. Cartwright

2016-10-01

Full Text Available Inhalation of multiwalled carbon nanotubes (MWCNTs during their manufacture or incorporation into various commercial products may cause lung inflammation, fibrosis, and oxidative stress in exposed workers. Some workers may be more susceptible to these effects because of differences in their ability to synthesize the major antioxidant and immune system modulator glutathione (GSH. Accordingly, in this study we examined the influence of GSH synthesis and gender on MWCNT-induced lung inflammation in C57BL/6 mice. GSH synthesis was impaired through genetic manipulation of Gclm, the modifier subunit of glutamate cysteine ligase, the rate-limiting enzyme in GSH synthesis. Twenty-four hours after aspirating 25 µg of MWCNTs, all male mice developed neutrophilia in their lungs, regardless of Gclm genotype. However, female mice with moderate (Gclm heterozygous and severe (Gclm null GSH deficiencies developed significantly less neutrophilia. We found no indications of MWCNT-induced oxidative stress as reflected in the GSH content of lung tissue and epithelial lining fluid, 3-nitrotyrosine formation, or altered mRNA or protein expression of several redox-responsive enzymes. Our results indicate that GSH-deficient female mice are rendered uniquely susceptible to an attenuated neutrophil response. If the same effects occur in humans, GSH-deficient women manufacturing MWCNTs may be at greater risk for impaired neutrophil-dependent clearance of MWCNTs from the lung. In contrast, men may have effective neutrophil-dependent clearance, but may be at risk for lung neutrophilia regardless of their GSH levels.

Intracellular drug delivery nanocarriers of glutathione-responsive degradable block copolymers having pendant disulfide linkages.

Science.gov (United States)

Khorsand, Behnoush; Lapointe, Gabriel; Brett, Christopher; Oh, Jung Kwon

2013-06-10

Self-assembled micelles of amphiphilic block copolymers (ABPs) with stimuli-responsive degradation (SRD) properties have a great promise as nanotherapeutics exhibiting enhanced release of encapsulated therapeutics into targeted cells. Here, thiol-responsive degradable micelles based on a new ABP consisting of a pendant disulfide-labeled methacrylate polymer block (PHMssEt) and a hydrophilic poly(ethylene oxide) (PEO) block were investigated as effective intracellular nanocarriers of anticancer drugs. In response to glutathione (GSH) as a cellular trigger, the cleavage of pendant disulfide linkages in hydrophobic PHMssEt blocks of micellar cores caused the destabilization of self-assembled micelles due to change in hydrophobic/hydrophilic balance. Such GSH-triggered micellar destabilization changed their size distribution with an appearance of large aggregates and led to enhanced release of encapsulated anticancer drugs. Cell culture results from flow cytometry and confocal laser scanning microscopy for cellular uptake as well as cell viability measurements for high anticancer efficacy suggest that new GSH-responsive degradable PEO-b-PHMssEt micelles offer versatility in multifunctional drug delivery applications.

Glutathione delays varies as-tocopherol oxidation and subsequent lipid peroxidation in rat liver microsomes

International Nuclear Information System (INIS)

Robey, S.; Mavis, R.

1986-01-01

A method has been developed for in vitro trace radiolabeling of rat liver microsomes with 3 H-α-tocopherol (αT*) which allows virtually complete oxidation of the αT* under oxidizing conditions. The supernatant of a 16,000 xg centrifugation of homogenized rat liver, containing the cytosolic rat liver vitamin E (VE) transfer protein, was incubated with an ethanolic solution of αT* for 10 minutes at 37 0 C. Labeled microsomes were collected in the washed 100,000 xg pellet. Microsomes were then incubated with 30 μM Fe 2+ in an NADPH-generating system, and both production of malondialdehyde (MDA) (a product of lipid peroxidation) and oxidation of αT* were monitored over a time course in the presence and absence of glutathione (GSH). The results indicate virtually complete oxidation of αT* precedes significant membrane lipid peroxidation, and that addition of 5 mM GSH delays both αT* oxidation and subsequent MDA production. This suggests that the previously observed VE-dependent heat labile inhibition of microsomal lipid peroxidation by GSH involves maintaining membrane levels of α-tocopherol

Molecular identification and functional delineation of a glutathione reductase homolog from disk abalone (Haliotis discus discus): Insights as a potent player in host antioxidant defense.

Science.gov (United States)

Herath, H M L P B; Wickramasinghe, P D S U; Bathige, S D N K; Jayasooriya, R G P T; Kim, Gi-Young; Park, Myoung Ae; Kim, Chul; Lee, Jehee

2017-01-01

Glutathione reductase (GSR) is an enzyme that catalyzes the biochemical conversion of oxidized glutathione (GSSG) into the reduced form (GSH). Since the ratio between the two forms of glutathione (GSH/GSSG) is important for the optimal function of GSH to act as an antioxidant against H 2 O 2 , the contribution of GSR as an enzymatic regulatory agent to maintain the proper ratio is essential. Abalones are marine mollusks that frequently encounter environmental factors that can trigger the overproduction of reactive oxygen species (ROS) such as H 2 O 2 . Therefore, we conducted the current study to reveal the molecular and functional properties of a GSR homolog in the disk abalone, Haliotis discus discus. The identified cDNA sequence (2325 bp) has a 1356 bp long open reading frame (ORF), coding for a 909 bp long amino acid sequence, which harbors a pyridine nucleotide-disulfide oxidoreductase domain (171-246 aa), a pyridine nucleotide-disulfide oxidoreductase dimerization domain, and a NAD(P)(+)-binding Rossmann fold superfamily signature domain. Four functional residues: the FAD binding site, glutathione binding site, NADPH binding motif, and assembly domain were identified to be conserved among the other species. The recombinant abalone GSR (rAbGSR) exhibited detectable activity in a standard glutathione reductase activity assay. The optimum pH and optimal temperature for the reaction were found to be 7.0 and 50 °C, respectively, while the ionic strength of the medium had no effect. The enzymatic reaction was vastly inhibited by Cu +2 and Cd +2 ions. A considerable effect of cellular protection was detected with a disk diffusion assay conducted with rAbGSR. Moreover, an MTT assay and flow cytometry confirmed the significance of the protective role of rAbGSR in cell function. Furthermore, AbGSR was found to be ubiquitously distributed in different types of abalone tissues. AbGSR mRNA expression was significantly upregulated in response to three immune challenges

Microwave-assisted synthesis of L-glutathione capped ZnSe QDs and its interaction with BSA by spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Ding, Ling, E-mail: linda0911@163.com [College of Chemical Engineering and Technology, Wuhan University of Science and Technology, Wuhan 430081 (China); College of Resource and Environmental Sciences, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan 430079 (China); Zhou, Pei-Jiang, E-mail: zhoupj@whu.edu.cn [College of Resource and Environmental Sciences, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan 430079 (China); Zhan, Hong-Ju [College of Resource and Environmental Sciences, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan 430079 (China); Jingchu University of Technology, Jingmen 448000 (China); Chen, Chi [College of Resource and Environmental Sciences, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan 430079 (China); Hu, Wei [Wuhan Humanwell Pharmaceutical Co. Ltd, Wuhan 430064 (China); Zhou, Teng-Fei; Lin, Chao-Wang [College of Resource and Environmental Sciences, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan 430079 (China)

2013-10-15

Stable, water-soluble and biologically compatible ZnSe quantum dots (QDs) with L-glutathione (GSH) as a capping agent were synthesized in aqueous medium by microwave irradiation. The GSH/Zn/Se molar ratios, reaction temperature, time and pH are the crucial factors for properties of QDs. Fluorescence (FL) spectra, absorption spectra, transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR) spectra studies showed that the optical properties of QDs were strong, shape of QDs was similar to spherical and the particle size was about 2–3 nm. The 42% quantum yield (QY) of QDs can be achieved without any post-preparative treatment. The interaction of QDs bioconjugated to bovine serum albumin (BSA) was also studied by absorption and FL spectra experiments. With addition of QDs, the FL intensity of BSA was largely quenched, which can be explained by static mechanism. The results suggested the QDs-BSA binding reaction was a static quenching. -- Highlights: • L-glutathione-capped ZnSe quantum dots were synthesized by microwave assisted in aqueous. • The facile synthesis of ZnSe QDs presented is simple and cost-effective. • Findings suggest the QDs possess highly quantum yield and narrow FWHM without any post-treatment. • The interaction mechanism between QDs and BSA is a static quenching.

Glutathione mediation of papain inactivation by hydrogen peroxide and hydroxyl radicals

International Nuclear Information System (INIS)

Lin, W.S.; Armstrong, D.A.

1977-01-01

Glutathione reacts with papainCys 25 SOH, formed by the reaction of papain with hydrogen peroxide, to give papainCys 25 SSG. Subsequent reaction of this mixed disulfide with glutathione is slow (k -1 sec -1 ). However, at 30 0 C it is readily cleaved by cysteine to form active papain, i.e., papainCys 25 SH. Glutathione resembles cysteine in protecting papain by the scavenging of .OH radicals, but, unlike cysteine, glutathione gave no evidence for the repair of enzyme radical lesions or for the conversion of papainCys 25 S. radicals to repairable derivatives. Its overall effectiveness for reducing the radiation inactivation of papain in aqueous solution is much less than that of cysteine

Hepatic and erythrocytic glutathione peroxidase activity in liver diseases.

Science.gov (United States)

Cordero, R; Ortiz, A; Hernández, R; López, V; Gómez, M M; Mena, P

1996-09-01

Hepatic and erythrocytic glutathione peroxidase activity, together with malondialdehyde levels, were determined as indicators of peroxidation in 83 patients from whom liver biopsies had been taken for diagnostic purposes. On histological study, the patients were classified into groups as minimal changes (including normal liver), steatosis, alcoholic hepatitis, hepatic cirrhosis, light to moderately active chronic hepatitis, and severe chronic active hepatitis. The glutathione peroxidase activity in erythrocytes showed no significant changes in any liver disease group. In the hepatic study, an increased activity was observed in steatosis with respect to the minimal changes group, this increased activity induced by the toxic agent in the initial stages of the alcoholic hepatic disease declining as the hepatic damage progressed. There was a negative correlation between the levels of hepatic malondialdehyde and hepatic glutathione peroxidase in subjects with minimal changes. This suggested the existence of an oxidative equilibrium in this group. This equilibrium is broken in the liver disease groups as was manifest in a positive correlation between malondialdehyde and glutathione peroxidase activity.

Alterations of energy metabolism and glutathione levels of HL-60 cells induced by methacrylates present in composite resins.

Science.gov (United States)

Nocca, G; De Palma, F; Minucci, A; De Sole, P; Martorana, G E; Callà, C; Morlacchi, C; Gozzo, M L; Gambarini, G; Chimenti, C; Giardina, B; Lupi, A

2007-03-01

Methacrylic compounds such as 2-hydroxyethyl methacrylate (HEMA), triethylene glycol dimethacrylate (TEGDMA) and bisphenol A glycerolate (1 glycerol/phenol) dimethacrylate (Bis-GMA) are largely present in auto- or photopolymerizable composite resins. Since the polymerization reaction is never complete, these molecules are released into the oral cavity tissues and biological fluids where they could cause local adverse effects. The aim of this work was to verify the hypothesis that the biological effects of HEMA, TEGDMA and Bis-GMA - at a non-cytotoxic concentration - depend on the interaction with mitochondria and exert consequent alterations of energy metabolism, GSH levels and the related pathways in human promyelocytic cell line (HL-60). The biological effects of methacrylic monomers were determined by analyzing the following parameters: GSH concentration, glucose-6-phosphate dehydrogenase (G6PDH) and glutathione reductase (GR) activity, oxygen and glucose consumption and lactate production along with cell differentiation and proliferation. All monomers induced both cellular differentiation and decrease in oxygen consumption. Cells treated with TEGDMA and Bis-GMA showed a significant enhancement of glucose consumption and lactate production. TEGDMA and HEMA induced GSH depletion stimulating G6PDH and GR activity. All the monomers under study affect the metabolism of HL-60 cells and show differentiating activity. Since alterations in cellular metabolism occurred at compound concentrations well below cytotoxic levels, the changes in energy metabolism and glutathione redox balance could be considered as potential mechanisms for inducing clinical and sub-clinical adverse effects and thus providing useful parameters when testing biocompatibility of dental materials.

Subcellular distribution of glutathione and cysteine in cyanobacteria

OpenAIRE

Zechmann, Bernd; Tomašić, Ana; Horvat, Lucija; Fulgosi, Hrvoje

2010-01-01

Glutathione plays numerous important functions in eukaryotic and prokaryotic cells. Whereas it can be found in virtually all eukaryotic cells, its production in prokaryotes is restricted to cyanobacteria and proteobacteria and a few strains of gram-positive bacteria. In bacteria, it is involved in the protection against reactive oxygen species (ROS), osmotic shock, acidic conditions, toxic chemicals, and heavy metals. Glutathione synthesis in bacteria takes place in two steps out of cysteine,...

Depletion by styrene of glutathione in plasma and bronchioalveolar lavage fluid of non-Swiss albino (NSA) mice.

Science.gov (United States)

Carlson, Gary P

2010-01-01

Styrene is a widely used chemical, but it is known to produce lung and liver damage in mice. This may be related to oxidative stress associated with the decrease in the levels of reduced glutathione (GSH) in the target tissues. The purpose of this study was to investigate the effect of styrene and its primary metabolites R-styrene oxide (R-SO) and S-styrene oxide (S-SO) on GSH levels in the lung lumen, as determined by amounts of GSH in bronchioalveolar lavage fluid (BALF) and in plasma. When non-Swiss albino (NSA) mice were administered styrene (600 mg/kg, ip), there was a significant fall in GSH levels in both BALF and plasma within 3 h. These returned to control levels by 12 h. The active metabolite R-SO (300 mg/kg, ip) also produced significant decreases in GSH in both BALF and plasma, but S-SO was without marked effect. Since GSH is a principal antioxidant in the lung epithelial lining fluid, this fall due to styrene may exert a significant influence on the ability of the lung to buffer oxidative damage.

Clinical findings and effect of sodium hydrogen carbonate in patients with glutathione synthetase deficiency.

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Gündüz, Mehmet; Ünal, Özlem; Kavurt, Sumru; Türk, Emrecan; Mungan, Neslihan Önenli

2016-04-01

Glutathione synthetase (GS) deficiency is a rare inborn error of glutathione (GSH) metabolism manifested by severe metabolic acidosis, hemolytic anemia, neurological problems and massive excretion of pyroglutamic acid (5-oxoproline) in the urine. The disorder has mild, moderate, and severe clinical variants. We aimed to report clinical and laboratory findings of four patients, effect of sodium hydrogen carbonate treatment and long-term follow up of three patients. Urine organic acid analysis was performed with gas chromatography-mass spectrometry. Molecular genetic analysis was performed in three patients, mutation was found in two of them. Enzyme analysis was performed in one patient. Clinical and laboratory findings of four patients were evaluated. One patient died at 4 months old, one patient's growth and development are normal, two patients have developed intellectual disability and seizures in the long term follow up period. Three patients benefited from sodium hydrogen carbonate treatment. The clinical picture varies from patient to patient, so it is difficult to predict the prognosis and the effectiveness of treatment protocols. We reported long term follow up of four patients and demonstrated that sodium hydrogen carbonate is effective for treatment of chronic metabolic acidosis in GS deficieny.

MDA and GSH-Px activity in transition dairy cows under seasonal variations and their relationship with reproductive performance

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Colakoglu Hatice Esra

2017-12-01

Full Text Available Introduction: The purpose of the current study was to evaluate the blood glutathione peroxidase (GSH-Px and malondialdehyde (MDA levels under seasonal variations in dairy cows during transition period, and to assess the relationship between chosen reproductive parameters, GSH-Px, and MDA.

CdTe quantum dots linked to Glutathione as a bridge for protein crosslinking

International Nuclear Information System (INIS)

Beato-López, J.J.; Espinazo, M.L.; Fernández-Ponce, C.; Blanco, E.; Ramírez-del-Solar, M.; Domínguez, M.; García-Cózar, F.; Litrán, R.

2017-01-01

We have optimized a synthetic method for the preparation of water soluble CdTe quantum dots (QDs), capped with glutathione (GSH) molecules, chemically bound to the nanoparticle surface (GSH-CdTe QDs). These QDs have been prepared by a co-precipitation reaction, in the presence of GSH. Modulating the temperature (from 90 to 145 °C) and the heating time (from 1 to 9 hours) we have obtained QDs of different sizes with a narrow size distribution, high water solubility and a fluorescent emission of a relatively high quantum yield (QY). Absorption and position of the fluorescent emission band show a strong dependence on QD size. The percentage of GSH linked to the QD surface has been estimated from chemical analysis and confirmed by thermogravimetry. The capping using this peptide, via the thiol group, converts these QDs in powerful tools as biomarkers for selective, fast and sensitive imaging in Biomedicine. The ability of these QDs to be biofunctionalized with a protein (a fundamental step for their use as biological probes) has been demonstrated. Surface functionalization of QDs is the fundamental aspect in the design of QDs for biomedical applications. In this work, the GSH-CdTe QDs have been efficiently bioconjugated with a protein extract from Dermatophagoides pteronyssinus. We have demonstrated that the GSH capping is a valuable means for subsequent protein crosslinking. Based on our results, we can conclude that proteins from Dermatophagoides pteronyssinus can be linked to GSH-CdTe QDs terminal groups. These results reveal that these GSH-capped QD probes, with high fluorescent intensity and a well functionalized surface that can be crosslinked to proteins, can have potential applications in targeted cell imaging.

Low glutathione regulates gene expression and the redox potentials of the nucleus and cytosol in Arabidopsis thaliana.

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Schnaubelt, Daniel; Queval, Guillaume; Dong, Yingping; Diaz-Vivancos, Pedro; Makgopa, Matome Eugene; Howell, Gareth; De Simone, Ambra; Bai, Juan; Hannah, Matthew A; Foyer, Christine H

2015-02-01

Reduced glutathione (GSH) is considered to exert a strong influence on cellular redox homeostasis and to regulate gene expression, but these processes remain poorly characterized. Severe GSH depletion specifically inhibited root meristem development, while low root GSH levels decreased lateral root densities. The redox potential of the nucleus and cytosol of Arabidopsis thaliana roots determined using roGFP probes was between -300 and -320 mV. Growth in the presence of the GSH-synthesis inhibitor buthionine sulfoximine (BSO) increased the nuclear and cytosolic redox potentials to approximately -260 mV. GSH-responsive genes including transcription factors (SPATULA, MYB15, MYB75), proteins involved in cell division, redox regulation (glutaredoxinS17, thioredoxins, ACHT5 and TH8) and auxin signalling (HECATE), were identified in the GSH-deficient root meristemless 1-1 (rml1-1) mutant, and in other GSH-synthesis mutants (rax1-1, cad2-1, pad2-1) as well as in the wild type following the addition of BSO. Inhibition of auxin transport had no effect on organ GSH levels, but exogenous auxin decreased the root GSH pool. We conclude that GSH depletion significantly increases the redox potentials of the nucleus and cytosol, and causes arrest of the cell cycle in roots but not shoots, with accompanying transcript changes linked to altered hormone responses, but not oxidative stress. © 2013 John Wiley & Sons Ltd.

No net splanchnic release of glutathione in man during N-acetylcysteine infusion

DEFF Research Database (Denmark)

Poulsen, H E; Vilstrup, H; Almdal, T

1993-01-01

Glutathione and amino acid concentrations were measured in arterial and hepatic vein plasma in four healthy volunteers and two patients with cirrhosis. There was no significant splanchnic efflux of glutathione (95% confidence limits, -0.501 to 0.405 mumol/min). After infusion of N...... to 0.97 +/- 0.11 (mean +/- SEM; p amino acids corresponded to an increased load on hepatic metabolic N conversion and transamination among nonessential amino acids. Splanchnic uptake of serine, alanine, cystine, isoleucine, and phenylalanine increased...... after NAC compatible with stimulated hepatic glutathione synthesis. In contrast to the rat, plasma glutathione in man probably originates mainly from extrahepatic tissues....

Auranofin induces apoptosis and necrosis in HeLa cells via oxidative stress and glutathione depletion.

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You, Bo Ra; Shin, Hye Rim; Han, Bo Ram; Kim, Suhn Hee; Park, Woo Hyun

2015-02-01

Auranofin (Au), an inhibitor of thioredoxin reductase, is a known anti‑cancer drug. In the present study, the anti‑growth effect of Au on HeLa cervical cancer cells was examined in association with levels of reactive oxygen species (ROS) and glutathione (GSH). Au inhibited the growth of HeLa cells with an IC50 of ~2 µM at 24 h. This agent induced apoptosis and necrosis, accompanied by the cleavage of poly (ADP‑ribose) polymerase and loss of mitochondrial membrane potential. The pan‑caspase inhibitor, benzyloxycarbonyl‑Val‑Ala‑Asp‑fluoromethylketone, prevented apoptotic cell death and each of the assessed caspase inhibitors inhibited necrotic cell death induced by Au. With respect to the levels of ROS and GSH, Au increased intracellular O2•- in the HeLa cells and induced GSH depletion. The pan‑caspase inhibitor reduced the levels of O2•- and GSH depletion in Au‑treated HeLa cells. The antioxidant, N‑acetyl cysteine, not only attenuated apoptosis and necrosis in the Au‑treated HeLa cells, but also decreased the levels of O2•- and GSH depletion in the cells. By contrast, L‑buthionine sulfoximine, a GSH synthesis inhibitor, intensified cell death O2•- and GSH depletion in the Au‑treated HeLa cells. In conclusion, Au induced apoptosis and necrosis in HeLa cells via the induction of oxidative stress and the depletion of GSH.

Lack of oxygen effect in glutathione-deficient human cells in culture

International Nuclear Information System (INIS)

Edgren, M.; Larsson, A.; Nilsson, K.; Revesz, L.; Scott, O.C.A.

1980-01-01

The frequency of X-ray-induced DNA breaks was determined in human cell lines which are deficient in glutathione synthetase and have a greatly reduced glutathione content. Hydroxyapatite chromatography was used for the estimation of the DNA breaks in cell cultures, which were derived either from lymphoblasts transformed by infection with EB virus or from fibroblasts. The dose-effect relationship for the induction of breaks when radiation exposure was made in argon, was similar to that found when exposure was made in air. In control cultures with normal glutathione content, the induction of breaks was enhanced when irradiation was made under aerobic, instead of anaerobic, conditions. Treatment of the glutathione-deficient cells with the hypoxic radiosensitizer misonidazole did not enhance the induction of breaks by radiation delivered either in air or in argon. In control cultures, radiation induction of breaks was enhanced by misonidazole under anaerobic but not under aerobic conditions. When the glutathione-deficient cells were pretreated with cysteamine however, irradiation in the absence of oxygen resulted in a decreased frequency of DNA breaks. (author)

Effect of glutathione depletion on the aerobic radiation response of A549 human lung carcinoma cells

International Nuclear Information System (INIS)

Biaglow, J.E.; Clark, E.P.; Varnes, M.E.; Tuttle, S.W.; Epp, E.R.

1985-01-01

The authors demonstrated that depletion of glutathione (GSH) from cultured A549 cells to non-detectable levels, using L-buthionine sulfoximine (L-BSO), results in an increased aerobic radiation response. This response can be further increased if dimethylfumarate (DMF) is added concurrently with L-BSO. L-BSO is a relatively slow depletor of GSH compared to DMF, which acts by both spontaneous and enzyme catalysed reactions. The authors have studied: 1. the effect of continuous long-term exposure to 0.1 mM L-BSO on GSH levels and the subsequent radiation response and 2. the effect of GSH depletion on enzymes essential for radical detoxification. The results show an enhanced aerobic radiation response that increases with the time of exposure to L-BSO. For example surviving fraction (S.F.) after 5 Gy for cells exposed to L-BSO for 24 hrs is 0.004 and 0.08 for control cultures. Cells washed free of medium and irradiated in Hanks' show 0.0007 S.F. after 120 hr exposure to L-BSO and S.F. of 0.075 for the control cultures. The relationship between the chronic GSH depleted state, GSH peroxidase, and radiation induced lipid peroxidation is being investigated

Transcriptional regulation of the Hansenula polymorpha GSH2 gene in the response to cadmium ion treatment

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O. V. Blazhenko

2014-02-01

Full Text Available In a previous study we cloned GSH2 gene, encoding γ-glutamylcysteine synthetase (γGCS in the yeast Hansenula рolymorpha. In this study an analysis of molecular organisation of the H. рolymorpha GSH2 gene promoter was conducted and the potential binding sites of Yap1, Skn7, Creb/Atf1, and Cbf1 transcription factors were detected. It was established that full regulation of GSH2 gene expression in the response to cadmium and oxidative stress requires the length of GSH2 promoter to be longer than 450 bp from the start of translation initiation. To study the transcriptional regulation of H. polymorpha GSH2 gene recombinant strain, harbouring­ a reporter system, in which 1.832 kb regulatory region of GSH2 gene was fused to structural and terminatory regions of alcohol oxidase gene, was constructed. It was shown that maximum increase in H. polymorpha GSH2 gene transcription by 33% occurs in the rich medium under four-hour incubation with 1 μM concentration of cadmium ions. In the minimal medium the GSH2 gene expression does not correlate with the increased total cellular glutathione levels under cadmium ion treatment. We assume that the increased content of total cellular glutathione under cadmium stress in the yeast H. polymorpha probably is not controlled on the level of GSH2 gene transcription.

Plaque formation reduction with glutathione monoester in mice fed on atherogenic diet

International Nuclear Information System (INIS)

Iqbal, M.; Mehboobali, N.; Pervez, S.

2006-01-01

To determine the role of glutathione monoester on reducing the development of plaque formation in an animal model. Twenty-four Balb/c mice were divided into 3 equal groups. First group was fed on atherogenic diet alone, while the second group received atherogenic diet plus twice weekly injections of glutathione monoester. The third group was fed on normal diet for mice. After one year, the animals were sacrificed. Blood was analyzed for lipid levels, while liver, kidney, spleen, heart and aorta were removed to study morphological changes. Results: In the groups of mice receiving atherogenic diet (with and without glutathione monoesters), there was significant increase in levels of total cholesterol (p=0.011) and LDL cholesterol (p=0.001) compared to levels of these lipids in mice on normal diet. However, a significant decrease in levels of triglycerides (p=0.01) was observed in the group receiving atherogenic diet along with glutathione monoester. Supplementation with glutathione monoester had the most pronounced effect only on triglyceride levels. Atherosclerotic plaques were seen in heart and/or aorta of mice receiving atherogenic diet. However, such plaques were either totally absent or if seen in an animal, were extremely small and diffuse in the group receiving glutathione monoester along with atherogenic diet. Mice on normal diet had no evidence of any plaque formation. Cholesterol granuloma was seen in liver of mice on atherogenic diet alone. In mice receiving atherogenic diet plus glutathione monoester, no cholesterol granuloma was found in liver. There were no remarkable morphological changes in spleen and kidney in the three groups of mice. Glutathione monoester appears to inhibit or reduce the development of plaque formation in mice. (author)

Glutathione in the human brain: Review of its roles and measurement by magnetic resonance spectroscopy.

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Rae, Caroline D; Williams, Stephen R

2017-07-15

We review the transport, synthesis and catabolism of glutathione in the brain as well as its compartmentation and biochemistry in different brain cells. The major reactions involving glutathione are reviewed and the factors limiting its availability in brain cells are discussed. We also describe and critique current methods for measuring glutathione in the human brain using magnetic resonance spectroscopy, and review the literature on glutathione measurements in healthy brains and in neurological, psychiatric, neurodegenerative and neurodevelopmental conditions In summary: Healthy human brain glutathione concentration is ∼1-2 mM, but it varies by brain region, with evidence of gender differences and age effects; in neurological disease glutathione appears reduced in multiple sclerosis, motor neurone disease and epilepsy, while being increased in meningiomas; in psychiatric disease the picture is complex and confounded by methodological differences, regional effects, length of disease and drug-treatment. Both increases and decreases in glutathione have been reported in depression and schizophrenia. In Alzheimer's disease and mild cognitive impairment there is evidence for a decrease in glutathione compared to age-matched healthy controls. Improved methods to measure glutathione in vivo will provide better precision in glutathione determination and help resolve the complex biochemistry of this molecule in health and disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Thioredoxin and glutathione systems differ in parasitic and free-living platyhelminths

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Salinas Gustavo

2010-04-01

Full Text Available Abstract Background The thioredoxin and/or glutathione pathways occur in all organisms. They provide electrons for deoxyribonucleotide synthesis, function as antioxidant defenses, in detoxification, Fe/S biogenesis and participate in a variety of cellular processes. In contrast to their mammalian hosts, platyhelminth (flatworm parasites studied so far, lack conventional thioredoxin and glutathione systems. Instead, they possess a linked thioredoxin-glutathione system with the selenocysteine-containing enzyme thioredoxin glutathione reductase (TGR as the single redox hub that controls the overall redox homeostasis. TGR has been recently validated as a drug target for schistosomiasis and new drug leads targeting TGR have recently been identified for these platyhelminth infections that affect more than 200 million people and for which a single drug is currently available. Little is known regarding the genomic structure of flatworm TGRs, the expression of TGR variants and whether the absence of conventional thioredoxin and glutathione systems is a signature of the entire platyhelminth phylum. Results We examine platyhelminth genomes and transcriptomes and find that all platyhelminth parasites (from classes Cestoda and Trematoda conform to a biochemical scenario involving, exclusively, a selenium-dependent linked thioredoxin-glutathione system having TGR as a central redox hub. In contrast, the free-living platyhelminth Schmidtea mediterranea (Class Turbellaria possesses conventional and linked thioredoxin and glutathione systems. We identify TGR variants in Schistosoma spp. derived from a single gene, and demonstrate their expression. We also provide experimental evidence that alternative initiation of transcription and alternative transcript processing contribute to the generation of TGR variants in platyhelminth parasites. Conclusions Our results indicate that thioredoxin and glutathione pathways differ in parasitic and free-living flatworms and

Thioredoxin and glutathione systems differ in parasitic and free-living platyhelminths

Science.gov (United States)

2010-01-01

Background The thioredoxin and/or glutathione pathways occur in all organisms. They provide electrons for deoxyribonucleotide synthesis, function as antioxidant defenses, in detoxification, Fe/S biogenesis and participate in a variety of cellular processes. In contrast to their mammalian hosts, platyhelminth (flatworm) parasites studied so far, lack conventional thioredoxin and glutathione systems. Instead, they possess a linked thioredoxin-glutathione system with the selenocysteine-containing enzyme thioredoxin glutathione reductase (TGR) as the single redox hub that controls the overall redox homeostasis. TGR has been recently validated as a drug target for schistosomiasis and new drug leads targeting TGR have recently been identified for these platyhelminth infections that affect more than 200 million people and for which a single drug is currently available. Little is known regarding the genomic structure of flatworm TGRs, the expression of TGR variants and whether the absence of conventional thioredoxin and glutathione systems is a signature of the entire platyhelminth phylum. Results We examine platyhelminth genomes and transcriptomes and find that all platyhelminth parasites (from classes Cestoda and Trematoda) conform to a biochemical scenario involving, exclusively, a selenium-dependent linked thioredoxin-glutathione system having TGR as a central redox hub. In contrast, the free-living platyhelminth Schmidtea mediterranea (Class Turbellaria) possesses conventional and linked thioredoxin and glutathione systems. We identify TGR variants in Schistosoma spp. derived from a single gene, and demonstrate their expression. We also provide experimental evidence that alternative initiation of transcription and alternative transcript processing contribute to the generation of TGR variants in platyhelminth parasites. Conclusions Our results indicate that thioredoxin and glutathione pathways differ in parasitic and free-living flatworms and that canonical enzymes

Functional analysis and localisation of a delta-class glutathione S-transferase from Sarcoptes scabiei.

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Pettersson, Eva U; Ljunggren, Erland L; Morrison, David A; Mattsson, Jens G

2005-01-01

The mite Sarcoptes scabiei causes sarcoptic mange, or scabies, a disease that affects both animals and humans worldwide. Our interest in S. scabiei led us to further characterise a glutathione S-transferase. This multifunctional enzyme is a target for vaccine and drug development in several parasitic diseases. The S. scabiei glutathione S-transferase open reading frame reported here is 684 nucleotides long and yields a protein with a predicted molecular mass of 26 kDa. Through phylogenetic analysis the enzyme was classified as a delta-class glutathione S-transferase, and our paper is the first to report that delta-class glutathione S-transferases occur in organisms other than insects. The recombinant S. scabiei glutathione S-transferase was expressed in Escherichia coli via three different constructs and purified for biochemical analysis. The S. scabiei glutathione S-transferase was active towards the substrate 1-chloro-2,4-dinitrobenzene, though the positioning of fusion partners influenced the kinetic activity of the enzyme. Polyclonal antibodies raised against S. scabiei glutathione S-transferase specifically localised the enzyme to the integument of the epidermis and cavities surrounding internal organs in adult parasites. However, some minor staining of parasite intestines was observed. No staining was seen in host tissues, nor could we detect any antibody response against S. scabiei glutathione S-transferase in sera from naturally S. scabiei infected dogs or pigs. Additionally, the polyclonal sera raised against recombinant S. scabiei glutathione S-transferase readily detected a protein from mites, corresponding to the predicted size of native glutathione S-transferase.

Contribution of Fdh3 and Glr1 to Glutathione Redox State, Stress Adaptation and Virulence in Candida albicans.

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Anna T Tillmann

Full Text Available The major fungal pathogen of humans, Candida albicans, is exposed to reactive nitrogen and oxygen species following phagocytosis by host immune cells. In response to these toxins, this fungus activates potent anti-stress responses that include scavenging of reactive nitrosative and oxidative species via the glutathione system. Here we examine the differential roles of two glutathione recycling enzymes in redox homeostasis, stress adaptation and virulence in C. albicans: glutathione reductase (Glr1 and the S-nitrosoglutathione reductase (GSNOR, Fdh3. We show that the NADPH-dependent Glr1 recycles GSSG to GSH, is induced in response to oxidative stress and is required for resistance to macrophage killing. GLR1 deletion increases the sensitivity of C. albicans cells to H2O2, but not to formaldehyde or NO. In contrast, Fdh3 detoxifies GSNO to GSSG and NH3, and FDH3 inactivation delays NO adaptation and increases NO sensitivity. C. albicans fdh3⎔ cells are also sensitive to formaldehyde, suggesting that Fdh3 also contributes to formaldehyde detoxification. FDH3 is induced in response to nitrosative, oxidative and formaldehyde stress, and fdh3Δ cells are more sensitive to killing by macrophages. Both Glr1 and Fdh3 contribute to virulence in the Galleria mellonella and mouse models of systemic infection. We conclude that Glr1 and Fdh3 play differential roles during the adaptation of C. albicans cells to oxidative, nitrosative and formaldehyde stress, and hence during the colonisation of the host. Our findings emphasise the importance of the glutathione system and the maintenance of intracellular redox homeostasis in this major pathogen.

Reactivity of Biliatresone, a Natural Biliary Toxin, with Glutathione, Histamine, and Amino Acids.

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Koo, Kyung A; Waisbourd-Zinman, Orith; Wells, Rebecca G; Pack, Michael; Porter, John R

2016-02-15

In our previous work, we identified a natural toxin, biliatresone, from Dysphania glomulifera and D. littoralis, endemic plants associated with outbreaks of biliary atresia in Australian neonatal livestock. Biliatresone is a very rare isoflavonoid with an α-methylene ketone between two phenyls, 1,2-diaryl-2-propenone, along with methylenedioxy, dimethoxyl, and hydroxyl functional groups, that causes extrahepatic biliary toxicity in zebrafish. The toxic core of biliatresone is a methylene in the α-position relative to the ketone of 1,2-diaryl-2-propenone that serves as an electrophilic Michael acceptor. The α-methylene of biliatresone spontaneously conjugated with water and methanol (MeOH), respectively, via Michael addition in a reverse phase high-performance liquid chromatography (RP-HPLC) analysis. We here report the reactivity of biliatresone toward glutathione (GSH), several amino acids, and other thiol- or imidazole-containing biomolecules. LC-MS and HPLC analysis of the conjugation reaction showed the reactivity of biliatresone to be in the order histidine > N-acetyl-d-cysteine (D-NAC) = N-acetyl-l-cysteine (L-NAC) > histamine > glutathione ≥ cysteine ≫ glycine > glutamate > phenylalanine, while serine and adenine had no reactivity due to intramolecular hydrogen bonding in the protic solvents. The reactivity of ethyl vinyl ketone (EVK, 1-penten-3-one), an example of a highly reactive α,ß-unsaturated ketone, toward GSH gave a 6.7-fold lower reaction rate constant than that of biliatresone. The reaction rate constant of synthetic 1,2-diaryl-2-propen-1-one (DP), a core structure of the toxic molecule, was 10-fold and 1.5-fold weaker in potency compared to the reaction rate constants of biliatresone and EVK, respectively. These results demostrated that the methylenedioxy, dimethoxyl, and hydroxyl functional groups of biliatresone contribute to the stronger reactivity of the Michael acceptor α-methylene ketone toward nucleophiles compared to that of DP

Glutathione Depletion Induced by c-Myc Downregulation Triggers Apoptosis on Treatment with Alkylating Agents1

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Biroccio, Annamaria; Benassi, Barbara; Fiorentino, Francesco; Zupi, Gabriella

2004-01-01

Abstract Here we investigate the mechanism(s) involved in the c-Myc-dependent drug response of melanoma cells. By using three M14-derived c-Myc low-expressing clones, we demonstrate that alkylating agents, cisplatin and melphalan, trigger apoptosis in the c-Myc antisense transfectants, but not in the parental line. On the contrary, topoisomerase inhibitors, adriamycin and camptothecin, induce apoptosis to the same extent regardless of c-Myc expression. Because we previously demonstrated that c-Myc downregulation decreases glutathione (GSH) content, we evaluated the role of GSH in the apoptosis induced by the different drugs. In control cells treated with one of the alkylating agents or the others, GSH depletion achieved by l-buthionine-sulfoximine preincubation opens the apoptotic pathway. The apoptosis proceeded through early Bax relocalization, cytochrome c release, and concomitant caspase-9 activation, whereas reactive oxygen species production and alteration of mitochondria membrane potential were late events. That GSH was determining in the c-Myc-dependent drug-induced apoptosis was demonstrated by altering the intracellular GSH content of the c-Myc low-expressing cells up to the level of controls. Indeed, GSH ethyl ester-mediated increase of GSH abrogated apoptosis induced by cisplatin and melphalan by inhibition of Bax/cytochrome c redistribution. The relationship among c-Myc, GSH content, and the response to alkylating agent has been also evaluated in the M14 Myc overexpressing clones as well as in the melanoma JR8 c-Myc antisense transfectants. All together, these results demonstrate that GSH plays a key role in governing c-Myc-dependent drug-induced apoptosis. PMID:15153331

The pulmonary inflammatory response to multiwalled carbon nanotubes is influenced by gender and glutathione synthesis.

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Cartwright, Megan M; Schmuck, Stefanie C; Corredor, Charlie; Wang, Bingbing; Scoville, David K; Chisholm, Claire R; Wilkerson, Hui-Wen; Afsharinejad, Zahra; Bammler, Theodor K; Posner, Jonathan D; Shutthanandan, Vaithiyalingam; Baer, Donald R; Mitra, Somenath; Altemeier, William A; Kavanagh, Terrance J

2016-10-01

Inhalation of multiwalled carbon nanotubes (MWCNTs) during their manufacture or incorporation into various commercial products may cause lung inflammation, fibrosis, and oxidative stress in exposed workers. Some workers may be more susceptible to these effects because of differences in their ability to synthesize the major antioxidant and immune system modulator glutathione (GSH). Accordingly, in this study we examined the influence of GSH synthesis and gender on MWCNT-induced lung inflammation in C57BL/6 mice. GSH synthesis was impaired through genetic manipulation of Gclm, the modifier subunit of glutamate cysteine ligase, the rate-limiting enzyme in GSH synthesis. Twenty-four hours after aspirating 25µg of MWCNTs, all male mice developed neutrophilia in their lungs, regardless of Gclm genotype. However, female mice with moderate (Gclm heterozygous) and severe (Gclm null) GSH deficiencies developed significantly less neutrophilia. We found no indications of MWCNT-induced oxidative stress as reflected in the GSH content of lung tissue and epithelial lining fluid, 3-nitrotyrosine formation, or altered mRNA or protein expression of several redox-responsive enzymes. Our results indicate that GSH-deficient female mice are rendered uniquely susceptible to an attenuated neutrophil response. If the same effects occur in humans, GSH-deficient women manufacturing MWCNTs may be at greater risk for impaired neutrophil-dependent clearance of MWCNTs from the lung. In contrast, men may have effective neutrophil-dependent clearance, but may be at risk for lung neutrophilia regardless of their GSH levels. Copyright © 2016. Published by Elsevier B.V.

Selective effects of whey protein concentrate on glutathione levels and apoptosis in rats with mammary tumors.

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Cheng, Shih-Hsuan; Tseng, Yang-Ming; Wu, Szu-Hsien; Tsai, Shih-Meng; Tsai, Li-Yu

2017-09-01

Glutathione (GSH) plays an important role in antioxidant defense and regulation of apoptosis. GSH deficiency is related to many diseases, including cancer, and increased GSH levels in cancer cells are associated with chemotherapy resistance because of resistance to apoptosis. In this study, we investigated the effects of whey protein concentrate (WPC), a precursor of GSH, in rats with mammary tumors induced by treatment with 7,12-dimethylbenz(a)anthracene (DMBA). DMBA treatment results in cellular changes that mimic the initiation and promotion of carcinogenesis of breast tissue. We aimed to examine the possible preventive effects of diets containing whey protein on DMBA-induced mammary tumors in rats. The results indicate that WPC (0.334 g/kg) supplementation significantly increased the liver GSH levels by 92%, and were accompanied by low Bax/Bcl-2 ratio (from 5 to 3) and cleaved caspase-3/procaspase-3 ratio (from 2.4 to 1.2) in DMBA-treated rats. Furthermore, tumor GSH levels were decreased by 47% in WPC-supplemented rats, which resulted in increased Bax/Bcl-2 ratio (from 0.9 to 2) and cleaved caspase-3/procaspase-3 ratio (from 1.1 to 2.7). In conclusion, supplementation with WPC could selectively deplete tumor GSH levels and, therefore, WPC supplementation might be a promising strategy to overcome treatment resistance in cancer therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

The improving effect of reduced glutathione on boar sperm cryotolerance is related with the intrinsic ejaculate freezability.

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Yeste, Marc; Estrada, Efrén; Pinart, Elisabeth; Bonet, Sergi; Miró, Jordi; Rodríguez-Gil, Joan E

2014-04-01

Reduced glutathione (GSH) improves boar sperm cryosurvival and fertilising ability when added to freezing extenders. Poor freezability ejaculates (PFE) are known to present lower resistance than good freezability ejaculates (GFE) to cryopreservation procedures. So far, no study has evaluated whether the ability of GSH to counteract the cryopreservation-induced injuries depends on ejaculate freezability (i.e. GFE vs. PFE). For this reason, thirty boar ejaculates were divided into three equal volume fractions and cryopreserved with or without GSH at a final concentration of either 2 or 5mM in freezing media. Before and after freeze-thawing, sperm quality was evaluated through analysis of viability, motility, integrity of outer acrosome membrane, ROS levels, integrity of nucleoprotein structure, and DNA fragmentation. Ejaculates were classified into two groups (GFE or PFE) according to their post-thaw sperm motility and viability assessments in negative control (GSH 0mM), after running cluster analyses. Values of each sperm parameter were then compared between treatments (GSH 0mM, GSH 2mM, GSH 5mM) and freezability groups (GFE, PFE). In the case of GFE, GSH significantly improved boar sperm cryotolerance, without differences between 2 and 5mM. In contrast, PFE freezability was significantly increased when supplemented with 5mM GSH, but not when supplemented with 2mM GSH. In conclusion, PFE need a higher concentration of GSH than GFE to improve their cryotolerance. Copyright © 2014 Elsevier Inc. All rights reserved.

Glutathione as a radical scavenger and the biological consequences of thiyl radical production

International Nuclear Information System (INIS)

Winterbourn, C.C.

1996-01-01

A large number of compounds that have toxic effects can be metabolised to free radicals and secondary reactive oxygen species. These may be directly damaging or affect cell function by altering regulatory mechanisms through changing redox status. Protection is provided by an integrated system of antioxidant defenses. This includes reduced glutathione (GSH), one of the functions of which is as a free radical scavenger. For GSH to be an effective radical scavenging antioxidant, therefore, it must act in concert with superoxide dismutase to remove the superoxide so generated. Superoxide is produced in a variety of metabolic processes. It is also a secondary product of radicals reacting with oxygen either directly or through GSH. The biological reactivity of superoxide has been the subject of much debate ever since the discovery of superoxide dismutase in 1968. It has more recently become apparent that its rapid reaction with nitric oxide to give peroxynitrite, and its ability to reversibly oxidise and inactivate iron sulphur enzymes, contribute to the toxicity of superoxide. Another mechanism that could be important involves addition reactions of superoxide with other radicals to give organic peroxides. This reaction, to form a tyrosine peroxide, has come to authors attention through the study of the scavenging of tyrosyl radicals by GSH. It is also shown that a tyrosine peroxide is a major product of the oxidation of tyrosine by neutrophils

Stress hormones promote growth of B16-F10 melanoma metastases: an interleukin 6- and glutathione-dependent mechanism

OpenAIRE

Valles, Soraya L; Benlloch, Mar?a; Rodriguez, Mar?a L; Mena, Salvador; Pellicer, Jos? A; Asensi, Miguel; Obrador, Elena; Estrela, Jos? M

2013-01-01

[EN] Background: Interleukin (IL)-6 (mainly of tumor origin) activates glutathione (GSH) release from hepatocytes and its interorgan transport to B16-F10 melanoma metastatic foci. We studied if this capacity to overproduce IL-6 is regulated by cancer cell-independent mechanisms. Methods: Murine B16-F10 melanoma cells were cultured, transfected with red fluorescent protein, injected i.v. into syngenic C57BL/6J mice to generate lung and liver metastases, and isolated from metastatic f...

Single-bilayer graphene oxide sheet tolerance and glutathione redox system significance assessment in faba bean (Vicia faba L.)

International Nuclear Information System (INIS)

Anjum, Naser A.; Singh, Neetu; Singh, Manoj K.; Shah, Zahoor A.; Duarte, Armando C.; Pereira, Eduarda; Ahmad, Iqbal

2013-01-01

Adsorbents based on single-bilayer graphene oxide sheet (hereafter termed “graphene oxide”) are widely used in contaminated environments cleanup which may easily open the avenues for their entry to different environmental compartments, exposure to organisms and their subsequent transfer to human/animal food chain. Considering a common food crop—faba bean (Vicia faba L.) germinating seedlings as a model plant system, this study assesses the V. faba-tolerance to different concentrations (0, 100, 200, 400, 800, and 1600 mg L −1 ) of graphene oxide (0.5–5 μm) and evaluates glutathione (γ-glutamyl-cysteinyl-glycine) redox system significance in this context. The results showed significantly increased V. faba sensitivity under three graphene oxide concentrations (in order of impact: 1,600 > 200 > 100 mg graphene oxide L −1 ), which was accompanied by decreased glutathione redox (reduced glutathione-to-oxidized glutathione) ratio, reduced glutathione pool, as well as significant and equally elevated activities of glutathione-regenerating (glutathione reductase) and glutathione-metabolizing (glutathione peroxidase; glutathione sulfo-transferase) enzymes. Contrarily, the two graphene oxide concentrations (in order of impact: 800 > 400 graphene oxide mg L −1 ) yielded promising results; where, significant improvements in V. faba health status (measured as increased graphene oxide tolerance) were clearly perceptible with increased ratio of the reduced glutathione-to-oxidized glutathione, reduced glutathione pool and glutathione reductase activity but decreased activities of glutathione-metabolizing enzymes. It is inferred that V. faba seedlings-sensitivity and/or tolerance to graphene oxide concentrations depends on both the cellular redox state (reduced glutathione-to-oxidized glutathione ratio) and the reduced glutathione pool which in turn are controlled by a finely tuned modulation of the coordination between glutathione-regenerating and glutathione

Single-bilayer graphene oxide sheet tolerance and glutathione redox system significance assessment in faba bean (Vicia faba L.)

Energy Technology Data Exchange (ETDEWEB)

Anjum, Naser A. [University of Aveiro, Centre for Environmental and Marine Studies (CESAM) and Department of Chemistry (Portugal); Singh, Neetu; Singh, Manoj K. [University of Aveiro, Center for Mechanical Technology and Automation (TEMA) and Department of Mechanical Engineering (Portugal); Shah, Zahoor A. [University of Toledo, Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences (United States); Duarte, Armando C.; Pereira, Eduarda; Ahmad, Iqbal, E-mail: ahmadr@ua.pt [University of Aveiro, Centre for Environmental and Marine Studies (CESAM) and Department of Chemistry (Portugal)

2013-07-15

Adsorbents based on single-bilayer graphene oxide sheet (hereafter termed 'graphene oxide') are widely used in contaminated environments cleanup which may easily open the avenues for their entry to different environmental compartments, exposure to organisms and their subsequent transfer to human/animal food chain. Considering a common food crop-faba bean (Vicia faba L.) germinating seedlings as a model plant system, this study assesses the V. faba-tolerance to different concentrations (0, 100, 200, 400, 800, and 1600 mg L{sup -1}) of graphene oxide (0.5-5 {mu}m) and evaluates glutathione ({gamma}-glutamyl-cysteinyl-glycine) redox system significance in this context. The results showed significantly increased V. faba sensitivity under three graphene oxide concentrations (in order of impact: 1,600 > 200 > 100 mg graphene oxide L{sup -1}), which was accompanied by decreased glutathione redox (reduced glutathione-to-oxidized glutathione) ratio, reduced glutathione pool, as well as significant and equally elevated activities of glutathione-regenerating (glutathione reductase) and glutathione-metabolizing (glutathione peroxidase; glutathione sulfo-transferase) enzymes. Contrarily, the two graphene oxide concentrations (in order of impact: 800 > 400 graphene oxide mg L{sup -1}) yielded promising results; where, significant improvements in V. faba health status (measured as increased graphene oxide tolerance) were clearly perceptible with increased ratio of the reduced glutathione-to-oxidized glutathione, reduced glutathione pool and glutathione reductase activity but decreased activities of glutathione-metabolizing enzymes. It is inferred that V. faba seedlings-sensitivity and/or tolerance to graphene oxide concentrations depends on both the cellular redox state (reduced glutathione-to-oxidized glutathione ratio) and the reduced glutathione pool which in turn are controlled by a finely tuned modulation of the coordination between glutathione-regenerating and

Intracellular glutathione status regulates mouse bone marrow monocyte-derived macrophage differentiation and phagocytic activity

International Nuclear Information System (INIS)

Kim, Jin-Man; Kim, Hyunsoo; Kwon, Soon Bok; Lee, Soo Young; Chung, Sung-Chang; Jeong, Dae-Won; Min, Byung-Moo

2004-01-01

Although a redox shift can regulate the development of cells, including proliferation, differentiation, and survival, the role of the glutathione (GSH) redox status in macrophage differentiation remains unclear. In order to elucidate the role of a redox shift, macrophage-like cells were differentiated from the bone marrow-derived monocytes that were treated with a macrophage colony stimulating factor (M-CSF or CSF-1) for 3 days. The macrophagic cells were characterized by a time-dependent increase in three major symptoms: the number of phagocytic cells, the number of adherent cells, and the mRNA expression of c-fms, a M-CSF receptor that is one of the macrophage-specific markers and mediates development signals. Upon M-CSF-driven macrophage differentiation, the GSH/GSSG ratio was significantly lower on day 1 than that observed on day 0 but was constant on days 1-3. To assess the effect of the GSH-depleted and -repleted status on the differentiation and phagocytosis of the macrophages, GSH depletion by BSO, a specific inhibitor of the de novo GSH synthesis, inhibited the formation of the adherent macrophagic cells by the down-regulation of c-fms, but did not affect the phagocytic activity of the macrophages. To the contrary, GSH repletion by the addition of NAC, which is a GSH precursor, or reduced GSH in media had no effect on macrophage differentiation, and led to a decrease in the phagocytic activity. Furthermore, we observed that there is checkpoint that is capable of releasing from the inhibition of the formation of the adherent macrophagic cells according to GSH depletion by BSO. Summarizing, these results indicate that the intracellular GSH status plays an important role in the differentiation and phagocytosis of macrophages

Glutathione metabolism modelling: a mechanism for liver drug-robustness and a new biomarker strategy

NARCIS (Netherlands)

Geenen, S.; du Preez, F.B.; Snoep, J.L.; Foster, A.J.; Sarda, S.; Kenna, J.G.; Wilson, I.D.; Westerhoff, H.V.

2013-01-01

Background Glutathione metabolism can determine an individual's ability to detoxify drugs. To increase understanding of the dynamics of cellular glutathione homeostasis, we have developed an experiment-based mathematical model of the kinetics of the glutathione network. This model was used to

Synthesis, characterization, and cytotoxicity of glutathione-PEG-iron oxide magnetic nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Haddad, Paula S.; Santos, Marconi C. [Universidade Federal de São Paulo, UNIFESP, Exact and Earth Sciences Department (Brazil); Guzzi Cassago, Carolina Aparecida de [Universidade Estadual de Campinas, UNICAMP, Department of Biochemistry and Tissue Biology, Institute of Biology (Brazil); Bernardes, Juliana S. [National Nanotechnology Laboratory (LNNano), National Center for Energy and Materials (CNPEM) (Brazil); Jesus, Marcelo Bispo de [Universidade Estadual de Campinas, UNICAMP, Department of Biochemistry and Tissue Biology, Institute of Biology (Brazil); Seabra, Amedea B., E-mail: amedea.seabra@ufabc.edu.br [Universidade Federal de São Paulo, UNIFESP, Exact and Earth Sciences Department (Brazil)

2016-12-15

Recently, increasing interest is spent on the synthesis of superparamagnetic iron oxide nanoparticles, followed by their characterization and evaluation of cytotoxicity towards tumorigenic cell lines. In this work, magnetite (Fe{sub 3}O{sub 4}) nanoparticles were synthesized by the polyol method and coated with polyethylene glycol (PEG) and glutathione (GSH), leading to the formation of PEG-Fe{sub 3}O{sub 4} and GSH-PEG-Fe{sub 3}O{sub 4} nanoparticles. The nanoparticles were characterized by state-of-the-art techniques: dynamic light scattering (DLS), atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and superconducting quantum interference device (SQUID) magnetic measurements. PEG-Fe{sub 3}O{sub 4} and GSH-PEG-Fe{sub 3}O{sub 4} nanoparticles have crystallite sizes of 10 and 5 nm, respectively, indicating compression in crystalline lattice upon addition of GSH on the nanoparticle surface. Both nanoparticles presented superparamagnetic behavior at room temperature, and AFM images revealed the regular spherical shape of the nanomaterials and the absence of particle aggregation. The average hydrodynamic sizes of PEG-Fe{sub 3}O{sub 4} and GSH-PEG-Fe{sub 3}O{sub 4} nanoparticles were 69 ± 37 and 124 nm ± 75 nm, respectively. The cytotoxicity of both nanoparticles was screened towards human prostatic carcinoma cells (PC-3). The results demonstrated a decrease in PC-3 viability upon treatment with PEG-Fe{sub 3}O{sub 4} or GSH-PEG-Fe{sub 3}O{sub 4} nanoparticles in a concentration-dependent manner. However, the cytotoxicity was not time-dependent. Due to the superparamagnetic behavior of PEG-Fe{sub 3}O{sub 4} or GSH-PEG-Fe{sub 3}O{sub 4} nanoparticles, upon the application of an external magnetic field, those nanoparticles can be guided to the target site yielding local toxic effects to tumor cells with minimal side effects to normal tissues, highlighting the promising uses of iron oxide nanoparticles in

Post-fermentative production of glutathione by baker's yeast (S. cerevisiae) in compressed and dried forms.

Science.gov (United States)

Musatti, Alida; Manzoni, Matilde; Rollini, Manuela

2013-01-25

The study was aimed at investigating the best biotransformation conditions to increase intracellular glutathione (GSH) levels in samples of baker's yeast (Saccharomyces cerevisiae) employing either the commercially available compressed and dried forms. Glucose, GSH precursors amino acids, as well as other cofactors, were dissolved in a biotransformation solution and yeast cells were added (5%dcw). Two response surface central composite designs (RSCCDs) were performed in sequence: in the first step the influence of amino acid composition (cysteine, glycine, glutamic acid and serine) on GSH accumulation was investigated; once their formulation was set up, the influence of other components was studied. Initial GSH content was found 0.53 and 0.47%dcw for compressed and dried forms. GSH accumulation ability of baker's yeast in compressed form was higher at the beginning of shelf life, that is, in the first week, and a maximum of 2.04%dcw was obtained. Performance of yeast in dried form was not found satisfactory, as the maximum GSH level was 1.18%dcw. When cysteine lacks from the reaction solution, yeast cells do not accumulate GSH. With dried yeast, the highest GSH yields occurred when cysteine was set at 3 g/L, glycine and glutamic acid at least at 4 g/L, without serine. Employing compressed yeast, the highest GSH yields occurred when cysteine and glutamic acid were set at 2-3 g/L, while glycine and serine higher than 2 g/L. Results allowed to set up an optimal and feasible procedure to obtain GSH-enriched yeast biomass, with up to threefold increase with respect to initial content. Copyright © 2012 Elsevier B.V. All rights reserved.

Antidepressant-like responses in the forced swimming test elicited by glutathione and redox modulation.

Science.gov (United States)

Rosa, Juliana M; Dafre, Alcir Luiz; Rodrigues, Ana Lúcia S

2013-09-15

Glutathione (GSH) displays a broad range of functions, among them a role as a neuromodulator with some neuroprotective properties. Taking into account that oxidative stress has been associated with depressive disorders, this study investigated the possibility that GSH, a major cell antioxidant, elicits an antidepressant-like effect in mice. Thus, GSH was administered by i.c.v. route to mice that were tested in the forced swimming test and in the tail suspension test, two predictive tests for antidepressant drug activity. In addition, GSH metabolism and the redox environment were modulated in order to study the possible mechanisms underlying the effects of GSH in the forced swimming test. The administration of GSH decreased the immobility time in the forced swimming test (300-3000nmol/site) and tail suspension test (100-1000nmol/site), consistent with an antidepressant-like effect. GSH depletion elicited by l-buthionine sulfoximine (3.2μmol/site, i.c.v.) did not alter the antidepressant-like effect of GSH, whereas the inhibition of extracellular GSH catabolism by acivicin (100nmol/site, i.c.v.) prevented the antidepressant-like effect of GSH. Moreover, a sub-effective dose (0.01nmol/site, i.c.v.) of the oxidizing agent DTNB (5,5'-dithiobis(2-nitrobenzoic acid)) potentiated the effect of GSH (100nmol/site, i.c.v.), while the pretreatment (25-100mg/kg, i.p.) with the reducing agent DTT (dl-dithiothreitol) prevented the antidepressant-like effect of GSH (300nmol/site, i.c.v.). DTNB (0.1nmol/site, i.c.v.), produced an antidepressant-like effect, per se, which was abolished by DTT (25mg/kg, i.p.). The results show, for the first time, that centrally administered GSH produces an antidepressant-like effect in mice, which can be modulated by the GSH metabolism and the thiol/disulfide reagents. The redox environment may constitute a new venue for future antidepressant-drug development. Copyright © 2013 Elsevier B.V. All rights reserved.

Newly identified protein Imi1 affects mitochondrial integrity and glutathione homeostasis in Saccharomyces cerevisiae.

Science.gov (United States)

Kowalec, Piotr; Grynberg, Marcin; Pająk, Beata; Socha, Anna; Winiarska, Katarzyna; Fronk, Jan; Kurlandzka, Anna

2015-09-01

Glutathione homeostasis is crucial for cell functioning. We describe a novel Imi1 protein of Saccharomyces cerevisiae affecting mitochondrial integrity and involved in controlling glutathione level. Imi1 is cytoplasmic and, except for its N-terminal Flo11 domain, has a distinct solenoid structure. A lack of Imi1 leads to mitochondrial lesions comprising aberrant morphology of cristae and multifarious mtDNA rearrangements and impaired respiration. The mitochondrial malfunctioning is coupled to significantly decrease the level of intracellular reduced glutathione without affecting oxidized glutathione, which decreases the reduced/oxidized glutathione ratio. These defects are accompanied by decreased cadmium sensitivity and increased phytochelatin-2 level. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

CHANGES IN THE GLUTATHIONE SYSTEM IN P19 EMBRYONAL CARCINOMA CELLS UNDER HYPOXIC CONDITIONS

Directory of Open Access Journals (Sweden)

D. S. Orlov

2015-01-01

Full Text Available Introduction. According to modern perceptions, tumor growth, along with oxidative stress formation, is accompanied by hypoxia. Nowadays studying the regulation of cellular molecular system functioning by conformational changes in proteins appears to be a topical issue. Research goal was to evaluate the state of the glutathione system and the level of protein glutathionylation in P19 embryonal carcinoma (EC cells under hypoxic conditions.Material and methods. P19 EC cells (mouse embryonal carcinoma cultured under normoxic and hypox-ic conditions served the research material.The concentration of total, oxidized, reduced and protein-bound glutathione, the reduced to oxidized thiol ratio as well as glutathione peroxidase and glutathione reductase activity were determined by spectropho-tometry.Results. Glutathione imbalance was accompanied by a decrease in P19 EC cell redox status under hypox-ic conditions against the backdrop of a rise in protein-bound glutathione.Conclusions. As a result of the conducted study oxidative stress formation was identified when modeling hypoxia in P19 embryonal carcinoma cells. The rise in the concentration of protein-bound glutathione may indicate the role of protein glutathionylation in regulation of P19 cell metabolism and functions un-der hypoxia. 

Impact of glutathione on the allergenicity of the peach lipid transfer protein Pru p 3.

Science.gov (United States)

Gómez-Casado, C; Tordesillas, L; Kinkel, J; Starkl, P; Cuesta-Herranz, J; Roth-Walter F; Díaz-Perales, A; Jensen-Jarolim, E

2015-01-01

The allergenic potential of proteins can be altered under various physicochemical conditions. Glutathione (GSH) is a reducing agent that is used as an antioxidant in food products. We aimed to characterize the natural folding of peach proteins and test the allergenicity of reduced and natural Pru p 3, the major peach allergen. Pru p 3 was purified from peach, and its conformation was analyzed by means of circular dichroism. Using a thiol fluorescent probe, reduced proteins were detected in fresh peach. GSH-reduced Pru p 3 was tested in vitro for T-cell proliferation and in vivo using skin prick testing. GSH-reduced Pru p 3 produced variable skin prick reactions in peach-allergic patients. The proliferative response of peripheral blood mononuclear cells from allergic patients to reduced Pru p 3 tended to be less intense, whereas secretion of the cytokines IFN-γ, IL-5, and IL-10 was comparable. In a pool of sera from peach-allergic patients, reduction hardly impaired IgE-binding. Moreover, the stability of reduced Pru p 3 to gastrointestinal digestion was similar to that of the natural form. GSH can at least transiently reduce Pru p 3. We found that the effect of reduction on the allergenicity of Pru p 3 varied. Therefore, as an additive, GSH does not seem to eliminate the risk of reactions for peach-allergic patients.

Glutathione and the Antioxidant Potential of Binary Mixtures with Flavonoids: Synergisms and Antagonisms

Directory of Open Access Journals (Sweden)

Patrícia Valentão

2013-07-01

Full Text Available Polyphenols are able to trap free radicals, which contributes to their known antioxidant capacity. In plant extracts, these secondary metabolites may act in concert, in a way that their combined activities will be superior to their individual effects (synergistic interaction. Several polyphenols have demonstrated clear antioxidant properties in vitro, and many of their biological actions have been attributed to their intrinsic reducing capabilities. As so, the intake of these compounds at certain concentrations in the diet and/or supplementation may potentiate the activity of reduced form glutathione (GSH, thus better fighting oxidative stress. The aim of this work was to predict a structure-antioxidant activity relationship using different classes of flavonoids and to assess, for the first time, possible synergisms and antagonisms with GSH. For these purposes a screening microassay involving the scavenging of DPPH• was applied. In general, among the tested compounds, those lacking the catechol group in B ring showed antagonistic behaviour with GSH. Myricetin displayed additive effect, while quercetin, fisetin, luteolin, luteolin-7-O-glucoside, taxifolin and (+-catechin demonstrated synergistic actions. Furthermore, adducts formed at C2′ and C5′ of the B ring seem to be more important for the antioxidant capacity than adducts formed at C6 and C8 of the A ring.

Investigation of glutathione peroxidase activity in chicken meat under different experimental conditions

Directory of Open Access Journals (Sweden)

Alexandre José Cichoski

2012-12-01

Full Text Available Due to the fact that previous studies on the enzymatic activity of Glutathione peroxidase (GSH-Px diverge widely in their methodology and results, this study aimed to investigate the influence of different analytical conditions on GSH-Px activity in chicken thighs from broilers that were fed different diets with different sources and concentrations of selenium. GSH-Px activity was evaluated six hours after slaughter and 120 days after frozen storage at -18 ºC. The different analytical conditions included time of pre-incubation (0, 10 and 30 minutes, reaction medium, types of substrate (H2O2 (0.72 mM, 7.2 mM, and 72 mM and Terc-butil hydroperoxide 15 mM, and different buffer concentrations (buffer 1, potassium phosphate 50 mM pH 7.0 + EDTA 1 mM + mercaptoethanol 1 mM, and buffer 2, tris-HCl 50 mM pH 7.6 + EDTA 1 mM + mercapthanol 5 mM. The results show that the highest GSH-Px activity was observed when enzyme and substrate were in contact at 22 ºC without any pre-incubation, and that, when used at concentrations above 0.72 mM, hydrogen peroxide saturated the GSH-Px enzyme and inhibited its activity. The enzyme presented higher affinity to hydrogen peroxide when compared to terc-butil peroxide, and the addition of a buffer containing mercaptoethanol did not increase GSH-Px enzymatic activity. The activity of GSH-Px was not influenced by the source and concentration of selenium in the diet either. The obtained results allowed the determination of the best temperature of contact between the enzyme and substrate (22 ºC, the optimum concentration, and the type of substrate and buffer to be used. This information is extremely useful for future studies on GSH-Px activity in meat due to the divergence and little information found in the literature.

Control of ascorbic acid synthesis and accumulation and glutathione by the incident light red/far red ratio in Phaseolus vulgaris leaves.

Science.gov (United States)

Bartoli, Carlos G; Tambussi, Eduardo A; Diego, Fanello; Foyer, Christine H

2009-01-05

The effects of red/far red (R/FR) ratios on leaf ascorbate (AA) and glutathione (GSH) accumulation were examined in common bean (Phaseolus vulgaris L.). Growth under low R/FR ratios resulted in a "shade" phenotype and much lower leaf AA and GSH contents than high (R/FR) ratios. Photosynthesis rates were unaffected by changes in the R/FR ratio but leaf respiration rates, pyridine nucleotide pools and antioxidant enzyme activities were decreased under the low R/FR regime. The GSH pool changed slowly in response to altered R/FR ratios but leaf ascorbate acclimated over a single photoperiod. We conclude that light quality signals, particularly R/FR ratios, are important regulators of antioxidant synthesis and accumulation. These acclimatory changes are an early response to changing light environment.

The effect of excimer laser keratectomy on corneal glutathione-related enzymes in rabbits.

Science.gov (United States)

Bilgihan, Ayşe; Bilgihan, Kamil; Yis, Ozgür; Yis, Nilgün Safak; Hasanreisoglu, Berati

2003-04-01

Glutathione related enzymes are involved in the metabolism and detoxification of cytotoxic and carcinogenic compounds as well as reactive oxygen species. Excimer laser is a very useful tool for the treatment of refractive errors and removing superficial corneal opacities. Previous studies have shown that excimer laser may initiate free radical formation in the cornea. In the present study, we evaluated the effect of excimer laser keratectomy on corneal glutathione-related enzyme activities in rabbits. Animals were divided into five groups, and all groups were compared with the controls (group 1), after epithelial scraping (group 2), transepithelial photorefractive keratectomy (PRK) (group 3), traditional PRK (group 4) and deep traditional PRK (group 5). Corneal glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR) activities were measured after 24h. Corneal GPx and GR activities significantly decreased only in group 5 (p < 0.05) but GST activities significantly decreased in all groups when compared with the control group (p < 0.05). In conclusion, excimer laser inhibits the glutathione dependent defense system in the cornea, this effect becomes more prominent after high doses of excimer laser energy and antioxidants may be useful to reduce free radical mediated complications.

Glutathione Preservation during Storage of Rat Lenses in Optisol-GS and Castor Oil

DEFF Research Database (Denmark)

Holm, Thomas; Brøgger-Jensen, Martin Rocho; Johnson, Leif

2013-01-01

Glutathione concentration in the lens decreases in aging and cataractous lenses, providing a marker for tissue condition. Experimental procedures requiring unfrozen lenses from donor banks rely on transportation in storage medium, affecting lens homeostasis and alterations in glutathione levels. ....... The aim of the study was to examine the effects of Optisol-GS and castor oil on lens condition, determined from their ability to maintain glutathione concentrations....

Effects of EGCG and Chlorpyrifos on the Mortality, AChE and GSH of Adult Zebrafish: Independent and Combination

Science.gov (United States)

Zhang, Rong; Zhang, Jian; Gao, Qian; Guo, Nichun

2018-01-01

Chlorpyrifos is a neurotoxic agent and also causes oxidative stress in the body. EGCG is a typical strong antioxidant and has been reported to be neuroprotective. Our study investigated the mortality, the activity of acetylcholinesterase (AChE) in the brain and glutathione (GSH) in the liver of the adult Zebrafish in present of Chlorpyrifos and EGCG independent and combination. The results indicated that after the addition of EGCG, the mortality of zebrafish induced by Chlorpyrifos was reduced and the activity of AChE and glutathione (GSH) inhibited by Chlorpyrifos in zebrafish was significantly increased, which demonstrated that EGCG inhibited the toxicity Chlorpyrifos to zebrafish. The inhibition was dependent on the concentration of EGCG and Chlorpyrifos, which was not shown a gradual change trend but a complex situation.

Combining reduced glutathione and ascorbic acid has supplementary beneficial effects on boar sperm cryotolerance.

Science.gov (United States)

Giaretta, Elisa; Estrada, Efrén; Bucci, Diego; Spinaci, Marcella; Rodríguez-Gil, Joan E; Yeste, Marc

2015-02-01

The main aim of this work was to evaluate how supplementing freezing and thawing media with reduced glutathione (GSH) and l-ascorbic acid (AA) affected the quality parameters of frozen-thawed boar spermatozoa. With this purpose, semen samples of 12 ejaculates coming from 12 boars were used. Each ejaculate was split into seven aliquots to which 5 mM of GSH and 100 μM of AA were added separately or together at two different steps of freeze-thawing. Various sperm parameters (levels of free cysteine residues in sperm nucleoproteins, sperm viability, acrosome membrane integrity, intracellular peroxide and superoxide levels [ROS], and total and progressive motility) were evaluated before freezing and at 30 and 240 minutes after thawing. Both GSH and AA significantly improved boar sperm cryotolerance when they were separately added to freezing and thawing media. However, the highest improvement was recorded when both freezing and thawing media were supplemented with 5 mM of GSH plus 100 μM of AA. This improvement was observed in sperm viability and acrosome integrity, sperm motility, and nucleoprotein structure. Although ROS levels were not much increased by freeze-thawing procedures, the addition of GSH and AA to both freezing and thawing extenders significantly decreased intracellular peroxide levels and had no impact on superoxide levels. According to our results, we can conclude that supplementation of freezing and thawing media with both GSH and AA has a combined, beneficial effect on frozen-thawed boar sperm, which is greater than that obtained with the separate addition of either GSH or AA. Copyright © 2015 Elsevier Inc. All rights reserved.

Non-canonical regulation of glutathione and trehalose biosynthesis characterizes non-Saccharomyces wine yeasts with poor performance in active dry yeast production

Directory of Open Access Journals (Sweden)

Esther Gamero-Sandemetrio

2018-01-01

Full Text Available Several yeast species, belonging to Saccharomyces and non-Saccharomyces genera, play fundamental roles during spontaneous must grape fermentation, and recent studies have shown that mixed fermentations, co-inoculated with S. cerevisiae and non-Saccharomyces strains, can improve wine organoleptic properties. During active dry yeast (ADY production, antioxidant systems play an essential role in yeast survival and vitality as both biomass propagation and dehydration cause cellular oxidative stress and negatively affect technological performance. Mechanisms for adaptation and resistance to desiccation have been described for S. cerevisiae, but no data are available on the physiology and oxidative stress response of non-Saccharomyces wine yeasts and their potential impact on ADY production. In this study we analyzed the oxidative stress response in several non-Saccharomyces yeast species by measuring the activity of reactive oxygen species (ROS scavenging enzymes, e.g., catalase and glutathione reductase, accumulation of protective metabolites, e.g., trehalose and reduced glutathione (GSH, and lipid and protein oxidation levels. Our data suggest that non-canonical regulation of glutathione and trehalose biosynthesis could cause poor fermentative performance after ADY production, as it corroborates the corrective effect of antioxidant treatments, during biomass propagation, with both pure chemicals and food-grade argan oil.

Activation of dihaloalkanes by glutathione conjugation and formation of DNA adducts

International Nuclear Information System (INIS)

Guengerich, F.P.; Peterson, L.A.; Cmarik, J.L.; Koga, N.; Inskeep, P.B.

1987-01-01

Ethylene dibromide (1,2-dibromoethane, EDB) can be activated to electrophilic species by either oxidative metabolism or conjugation with glutathione. Although conjugation is generally a route of detoxication, in this case it leads to genetic damage. The major DNA adduct has been identified as S-[2-(N 7 -guanyl)ethyl]glutathione, which is believed to arise via half-mustard and episulfonium ion intermediates. The adduct has a half-life of about 70 to 100 hr and does not appear to migrate to other DNA sites. Glutathione-dependent DNA damage by EDB was also demonstrated in human hepatocyte preparations. The possible relevance of this DNA adduct to genetic damage is discussed

Redox Signaling Mediated by Thioredoxin and Glutathione Systems in the Central Nervous System.

Science.gov (United States)

Ren, Xiaoyuan; Zou, Lili; Zhang, Xu; Branco, Vasco; Wang, Jun; Carvalho, Cristina; Holmgren, Arne; Lu, Jun

2017-11-01

The thioredoxin (Trx) and glutathione (GSH) systems play important roles in maintaining the redox balance in the brain, a tissue that is prone to oxidative stress due to its high-energy demand. These two disulfide reductase systems are active in various areas of the brain and are considered to be critical antioxidant systems in the central nervous system (CNS). Various neuronal disorders have been characterized to have imbalanced redox homeostasis. Recent Advances: In addition to their detrimental effects, recent studies have highlighted that reactive oxygen species/reactive nitrogen species (ROS/RNS) act as critical signaling molecules by modifying thiols in proteins. The Trx and GSH systems, which reversibly regulate thiol modifications, regulate redox signaling involved in various biological events in the CNS. In this review, we focus on the following: (i) how ROS/RNS are produced and mediate signaling in CNS; (ii) how Trx and GSH systems regulate redox signaling by catalyzing reversible thiol modifications; (iii) how dysfunction of the Trx and GSH systems causes alterations of cellular redox signaling in human neuronal diseases; and (iv) the effects of certain small molecules that target thiol-based signaling pathways in the CNS. Further study on the roles of thiol-dependent redox systems in the CNS will improve our understanding of the pathogenesis of many human neuronal disorders and also help to develop novel protective and therapeutic strategies against neuronal diseases. Antioxid. Redox Signal. 27, 989-1010.

Exploring the Lean Phenotype of Glutathione-Depleted Mice: Thiol, Amino Acid and Fatty Acid Profiles.

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Amany K Elshorbagy

Full Text Available Although reduced glutathione (rGSH is decreased in obese mice and humans, block of GSH synthesis by buthionine sulfoximine (BSO results in a lean, insulin-sensitive phenotype. Data is lacking about the effect of BSO on GSH precursors, cysteine and glutamate. Plasma total cysteine (tCys is positively associated with stearoyl-coenzyme A desaturase (SCD activity and adiposity in humans and animal models.To explore the phenotype, amino acid and fatty acid profiles in BSO-treated mice.Male C3H/HeH mice aged 11 weeks were fed a high-fat diet with or without BSO in drinking water (30 mmol/L for 8 weeks. Amino acid and fatty acid changes were assessed, as well as food consumption, energy expenditure, locomotor activity, body composition and liver vacuolation (steatosis.Despite higher food intake, BSO decreased particularly fat mass but also lean mass (both P<0.001, and prevented fatty liver vacuolation. Physical activity increased during the dark phase. BSO decreased plasma free fatty acids and enhanced insulin sensitivity. BSO did not alter liver rGSH, but decreased plasma total GSH (tGSH and rGSH (by ~70%, and liver tGSH (by 82%. Glutamate accumulated in plasma and liver. Urine excretion of cysteine and its precursors was increased by BSO. tCys, rCys and cystine decreased in plasma (by 23-45%, P<0.001 for all, but were maintained in liver, at the expense of decreased taurine. Free and total plasma concentrations of the SCD products, oleic and palmitoleic acids were decreased (by 27-38%, P <0.001 for all.Counterintuitively, block of GSH synthesis decreases circulating tCys, raising the question of whether the BSO-induced obesity-resistance is linked to cysteine depletion. Cysteine-supplementation of BSO-treated mice is warranted to dissect the effects of cysteine and GSH depletion on energy metabolism.

Astro research fellowship: the role of bcl-2 and glutathione in an antioxidant pathway to prevent radiation-induced apoptosis

International Nuclear Information System (INIS)

Vlachaki, Maria T.; Meyn, Raymond E.

1998-01-01

Purpose: The expression of the bcl-2 proto-oncogene has been associated with resistance to radiation-induced apoptosis. There is evidence that the bcl-2 protein acts in an antioxidant pathway to block the effects of reactive oxygen species that mediate apoptosis possibly by increasing the levels of intracellular glutathione. Our hypothesis is that pretreatment of radiation-sensitive cells, known to lack bcl-2 expression, with antioxidants will reduce radiation-induced apoptosis. For this purpose, the apoptotic response to radiation and the intracellular levels of GSH were tested before and after pretreatment with antioxidants in two murine lymphoma cell lines, a radiation-resistant, bcl-2- expressing (LY-ar) line and a radiation-sensitive, non-bcl-2-expressing (LY-as) line. Methods and Materials: LY-ar and LY-as cells were irradiated at 0,1,2,3, and 4 hours before collection. The intracellular levels of reduced (GSH) and oxidized (GSSG) glutathione were determined by the use of the fluorescent dye o-phthalaldehyde. LY-as cells were treated with GSH ethyl-ester for 1 and 2 hours after irradiation. Apoptotic response was measured by the DNA fragmentation assay. The radiation dose was 2.5 Gy. Results: After irradiation, the apoptotic rate of LY-ar and LY-as cells was 10-20% and 50-70% respectively. LY-ar cells had higher intracellular GSH and GSSG levels compared to LY-as cells by 69.9% and 91.9% respectively and the GSH/GSSG ratio in LY-ar and LY-as cells was 15.09 and 17.09 respectively. GSH levels did not change during the first 2 hours after irradiation; however, there was a 49% and 84% reduction at 3 and 4 hours after irradiation, respectively, times at which the LY-as cells have already fragmented their DNA. Treatment of LY-as cells with GSH ethyl-ester at a concentration of 7 mM for 1 and 2 hours resulted in 70% and 231% increases in the intracellular GSH levels respectively. Treatment of LY-as cells with GSH ethyl-ester for 1 and 2 hours also conferred a 25

Impaired cross-talk between the thioredoxin and glutathione systems is related to ASK-1 mediated apoptosis in neuronal cells exposed to mercury.

Science.gov (United States)

Branco, Vasco; Coppo, Lucia; Solá, Susana; Lu, Jun; Rodrigues, Cecília M P; Holmgren, Arne; Carvalho, Cristina

2017-10-01

Mercury (Hg) compounds target both cysteine (Cys) and selenocysteine (Sec) residues in peptides and proteins. Thus, the components of the two major cellular antioxidant systems - glutathione (GSH) and thioredoxin (Trx) systems - are likely targets for mercurials. Hg exposure results in GSH depletion and Trx and thioredoxin reductase (TrxR) are prime targets for mercury. These systems have a wide-range of common functions and interaction between their components has been reported. However, toxic effects over both systems are normally treated as isolated events. To study how the interaction between the glutathione and thioredoxin systems is affected by Hg, human neuroblastoma (SH-SY5Y) cells were exposed to 1 and 5μM of inorganic mercury (Hg 2+ ), methylmercury (MeHg) or ethylmercury (EtHg) and examined for TrxR, GSH and Grx levels and activities, as well as for Trx redox state. Phosphorylation of apoptosis signalling kinase 1 (ASK1), caspase-3 activity and the number of apoptotic cells were evaluated to investigate the induction of Trx-mediated apoptotic cell death. Additionally, primary cerebellar neurons from mice depleted of mitochondrial Grx2 (mGrx2D) were used to examine the link between Grx activity and Trx function. Results showed that Trx was affected at higher exposure levels than TrxR, especially for EtHg. GSH levels were only significantly affected by exposure to a high concentration of EtHg. Depletion of GSH with buthionine sulfoximine (BSO) severely increased Trx oxidation by Hg. Notably, EtHg-induced oxidation of Trx was significantly enhanced in primary neurons of mGrx2D mice. Our results suggest that GSH/Grx acts as backups for TrxR in neuronal cells to maintain Trx turnover during Hg exposure, thus linking different mechanisms of molecular and cellular toxicity. Finally, Trx oxidation by Hg compounds was associated to apoptotic hallmarks, including increased ASK-1 phosphorylation, caspase-3 activation and increased number of apoptotic cells

A novel plant glutathione S-transferase/peroxidase suppresses Bax lethality in yeast

DEFF Research Database (Denmark)

Kampranis, S C; Damianova, R; Atallah, M

2000-01-01

The mammalian inducer of apoptosis Bax is lethal when expressed in yeast and plant cells. To identify potential inhibitors of Bax in plants we transformed yeast cells expressing Bax with a tomato cDNA library and we selected for cells surviving after the induction of Bax. This genetic screen allows...... for the identification of plant genes, which inhibit either directly or indirectly the lethal phenotype of Bax. Using this method a number of cDNA clones were isolated, the more potent of which encodes a protein homologous to the class theta glutathione S-transferases. This Bax-inhibiting (BI) protein was expressed...... in Escherichia coli and found to possess glutathione S-transferase (GST) and weak glutathione peroxidase (GPX) activity. Expression of Bax in yeast decreases the intracellular levels of total glutathione, causes a substantial reduction of total cellular phospholipids, diminishes the mitochondrial membrane...

Cadmium induced changes in subcellular glutathione contents within glandular trichomes of Cucurbita pepo L.

Science.gov (United States)

Kolb, Dagmar; Müller, Maria; Zellnig, Günther; Zechmann, Bernd

2010-07-01

Plants cope with cadmium (Cd) stress by complexation with phytochelatins (Pc), metallothioneins and glutathione and sequestration within vacuoles. Especially glutathione was found to play a major role in Cd detoxification as Cd shows a high binding affinity towards thiols and as glutathione is a precursor for Pc synthesis. In the present study, we have used an immunohistochemical approach combined with computer-supported transmission electron microscopy in order to measure changes in the subcellular distribution of glutathione during Cd-stress in mesophyll cells and cells of different glandular trichomes (long and short stalked) of Cucurbita pepo L. subsp. pepo var. styriaca GREB: . Even though no ultrastructural alterations were observed in leaf and glandular trichome cells after the treatment of plants with 50 microM cadmium chloride (CdCl(2)) for 48 h, all cells showed a large decrease in glutathione contents. The strongest decrease was found in nuclei and the cytosol (up to 76%) in glandular trichomes which are considered as a major side of Cd accumulation in leaves. The ratio of glutathione between the cytosol and nuclei and the other cell compartments was strongly decreased only in glandular trichomes (more than 50%) indicating that glutathione in these two cell compartments is especially important for the detoxification of Cd in glandular trichomes. Additionally, these data indicate that large amounts of Cd are withdrawn from nuclei during Cd exposure. The present study gives a detailed insight into the compartment-specific importance of glutathione during Cd exposure in mesophyll cells and glandular trichomes of C. pepo L. plants.

Nrf2-mediated antioxidant response by ethanolic extract of Sida cordifolia provides protection against alcohol-induced oxidative stress in liver by upregulation of glutathione metabolism.

Science.gov (United States)

Rejitha, S; Prathibha, P; Indira, M

2015-03-01

Objective The study aimed to evaluate the antioxidant property of ethanolic extract of Sida cordifolia (SAE) on alcohol-induced oxidative stress and to elucidate its mechanism of action. Methods Male albino rats of the Sprague-Dawley strain were grouped into four: (1) control, (2) alcohol (4 g/kg body weight), (3) SAE (50 mg/100 g body weight), and (4) alcohol (4 g/kg body weight) + SAE (50 mg/100 g body weight). Alcohol and SAE were given orally each day by gastric intubation. The duration of treatment was 90 days. Results The activities of toxicity markers in liver and serum increased significantly in alcohol-treated rats and to a lesser extent in the group administered SAE + alcohol. The activity of alcohol dehydrogenase and the reactive oxygen species level were increased significantly in alcohol-treated rats but attenuated in the SAE co-administered group. Oxidative stress was increased in alcohol-treated rats as evidenced by the lowered activities of antioxidant enzymes, decreased level of reduced glutathione (GSH), increased lipid peroxidation products, and decreased expression of γ-glutamyl cysteine synthase in liver. The co-administration of SAE with alcohol almost reversed these changes. The activity of glutathione-S-transferase and translocation of Nrf2 from cytosol to nucleus in the liver was increased in both the alcohol and alcohol + SAE groups, but the maximum changes were observed in the latter group. Discussion The SAE most likely elicits its antioxidant potential by reducing oxidative stress, enhancing the translocation of Nrf2 to nucleus and thereby regulating glutathione metabolism, leading to enhanced GSH content.

A novel mitochondria-targeted two-photon fluorescent probe for dynamic and reversible detection of the redox cycles between peroxynitrite and glutathione.

Science.gov (United States)

Sun, Chunlong; Du, Wen; Wang, Peng; Wu, Yang; Wang, Baoqin; Wang, Jun; Xie, Wenjun

2017-12-16

Redox homeostasis is important for maintenance of normal physiological functions within cells. Redox state of cells is primarily a consequence of precise balance between levels of reducing equivalents and reactive oxygen species. Redox homeostasis between peroxynitrite (ONOO - ) and glutathione (GSH) is closely associated with physiological and pathological processes, such as prolonged relaxation in vascular tissues and smooth muscle preparations, attenuation of hepatic necrosis, and activation of matrix metalloproteinase-2. We report a two-photon fluorescent probe (TP-Se) based on water-soluble carbazole-based compound, which integrates with organic selenium, to monitor changes in ONOO - /GSH levels in cells. This probe can reversibly respond to ONOO - and GSH and exhibits high selectivity, sensitivity, and mitochondrial targeting. The probe was successfully applied to visualize changes in redox cycles during ONOO - outbreak and antioxidant GSH repair in cells. The probe will lead to significant development on redox events involved in cellular redox regulation. Copyright © 2017 Elsevier Inc. All rights reserved.

ENDURANCE TRAINING AND GLUTATHIONE-DEPENDENT ANTIOXIDANT DEFENSE MECHANISM IN HEART OF THE DIABETIC RATS

Directory of Open Access Journals (Sweden)

Mustafa Atalay

2003-06-01

Full Text Available Regular physical exercise beneficially influences cardiac antioxidant defenses in normal rats. The aim of this study was to test whether endurance training can strengthen glutathione-dependent antioxidant defense mechanism and decrease lipid peroxidation in heart of the streptozotocin-induced diabetic rats. Redox status of glutathione in blood of diabetic rats in response to training and acute exercise was also examined. Eight weeks of treadmill training increased the endurance in streptozotocin-induced diabetic rats. It did not affect glutathione level in heart tissue at rest and also after exercise. On the other hand, endurance training decreased glutathione peroxidase activity in heart, while glutathione reductase and glutathione S-transferase activities were not affected either by acute exhaustive exercise or endurance training. Reduced and oxidized glutathione levels in blood were not affected by either training or acute exercise. Conjugated dienes levels in heart tissue were increased by acute exhaustive exercise and also 8 weeks treadmill training. Longer duration of exhaustion in trained group may have contributed to the increased conjugated dienes levels in heart after acute exercise. Our results suggest that endurance type exercise may make heart more susceptible to oxidative stress. Therefore it may be wise to combine aerobic exercise with insulin treatment to prevent its adverse effects on antioxidant defense in heart in patients with diabetes mellitus

Study on the influence of Sempervivum tectorum and Melatonin on Glutathion protective effects in rats blood exposed to Aluminum sulphate

OpenAIRE

Corina Gravila; Florin Muselin; Camelia Tulcan; Mirela Ahmadi – Khoie; Ariana- Bianca Velciov; Georgeta- Sofia Pintilie

2014-01-01

The present study was carried out to investigate the influence of Sempervivum tectorum aqueous extract and melatonin on reduced glutathione (GSH) protective effect in Wistar albino rat blood exposed to aluminium sulphate- Al2(SO4)3. The rats were divided in one control group (C) and 7 experimental groups (E). The control group received tap water. The experimental rats were feed the following way: E1 group – aluminum sulphate, daily, for 3 months; : E2 group – Sempervivum tectorum, daily, for ...

Structures of a putative ζ-class glutathione S-transferase from the pathogenic fungus Coccidioides immitis

International Nuclear Information System (INIS)

Edwards, Thomas E.; Bryan, Cassie M.; Leibly, David J.; Dieterich, Shellie H.; Abendroth, Jan; Sankaran, Banumathi; Sivam, Dhileep; Staker, Bart L.; Van Voorhis, Wesley C.; Myler, Peter J.; Stewart, Lance J.

2011-01-01

The pathogenic fungus C. immitis causes coccidioidomycosis, a potentially fatal disease. Here, apo and glutathione-bound crystal structures of a previously uncharacterized protein from C. immitis that appears to be a ζ-class glutathione S-transferase are presented. Coccidioides immitis is a pathogenic fungus populating the southwestern United States and is a causative agent of coccidioidomycosis, sometimes referred to as Valley Fever. Although the genome of this fungus has been sequenced, many operons are not properly annotated. Crystal structures are presented for a putative uncharacterized protein that shares sequence similarity with ζ-class glutathione S-transferases (GSTs) in both apo and glutathione-bound forms. The apo structure reveals a nonsymmetric homodimer with each protomer comprising two subdomains: a C-terminal helical domain and an N-terminal thioredoxin-like domain that is common to all GSTs. Half-site binding is observed in the glutathione-bound form. Considerable movement of some components of the active site relative to the glutathione-free form was observed, indicating an induced-fit mechanism for cofactor binding. The sequence homology, structure and half-site occupancy imply that the protein is a ζ-class glutathione S-transferase, a maleylacetoacetate isomerase (MAAI)

Cosensitization Properties of Glutathione-Protected Au25 Cluster on Ruthenium Dye-Sensitized TiO2 Photoelectrode

Directory of Open Access Journals (Sweden)

Kazuya Nakata

2013-01-01

Full Text Available Cosensitization by glutathione-protected Au25 clusters on Ru complex, N719-sensitized TiO2 photoelectrodes is demonstrated. Glutathione-protected Au25 clusters showed no significant changes in properties after adsorption onto TiO2 particles, as confirmed by optical absorption spectroscopy, transmission electron microscopy, and laser desorption/ionization mass spectrometry. Adsorption property of the glutathione-protected Au25 clusters depends on the pH, which affects the incident photon-to-current conversion efficiency (IPCE of the TiO2 photoelectrode containing Au25 clusters. When pH 7. The IPCE of a TiO2 photoelectrode sensitized by both glutathione-protected Au25 clusters and N719 was increased compared with photoelectrodes containing either glutathione-protected Au25 clusters or N719, which suggests that glutathione-protected Au25 clusters act as a coadsorbent for N719 on TiO2 photoelectrodes. This is also supported by the results that the IPCE of N719-sensitized TiO2 photoelectrodes increased upon addition of glutathione. Furthermore, cosensitization by glutathione-protected Au25 clusters on N719-sensitized TiO2 photoelectrodes allows that wavelength of photoelectric conversion was extended to the near infrared (NIR region. These results suggest that glutathione-protected Au25 clusters act not only as a coadsorbent to increase IPCE but also as an NIR-active sensitizer.