Showing papers on "Glutathione published in 2010"
TL;DR: The biochemistry of ROS and their production sites, and ROS scavenging antioxidant defense machinery are described, which protects plants against oxidative stress damages.
8,259 citations
TL;DR: In this article, the effect of heavy metals exposure to plants and role of GSH and PCs in heavy metal stress tolerance were reviewed and genetic manipulations of both GSH levels and PC levels were presented.
1,276 citations
TL;DR: It is shown that the protective effects of CR on oxidative stress and damage are diminished in mice lacking SIRT3, a mitochondrial deacetylase, a major mitochondrial antioxidant enzyme.
1,123 citations
TL;DR: These findings suggest that Sirt3-dependent mitochondrial adaptations may be a central mechanism of aging retardation in mammals and suggest that CR reduces oxidative DNA damage in multiple tissues and prevents AHL in wild-type mice but fails to modify these phenotypes in mice lacking the mitochondrial deacetylase Sirt 3.
1,033 citations
TL;DR: The double-edged effects of dietary originating antioxidants with a focus on the most abundant compounds, especially polyphenols, vitamin C, vitamin E and carotenoids are examined, highlighting that antioxidants at physiological doses are generally safe, exhibiting interesting health beneficial effects.
Abstract: The balance between oxidation and antioxidation is believed to be critical in maintaining healthy biological systems. Under physiological conditions, the human antioxidative defense system including e.g., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH) and others, allows the elimination of excess reactive oxygen species (ROS) including, among others superoxide anions (O2(·-)), hydroxyl radicals (OH·), alkoxyl radicals (RO·) and peroxyradicals (ROO·). However, our endogenous antioxidant defense systems are incomplete without exogenous originating reducing compounds such as vitamin C, vitamin E, carotenoids and polyphenols, playing an essential role in many antioxidant mechanisms in living organisms. Therefore, there is continuous demand for exogenous antioxidants in order to prevent oxidative stress, representing a disequilibrium redox state in favor of oxidation. However, high doses of isolated compounds may be toxic, owing to prooxidative effects at high concentrations or their potential to react with beneficial concentrations of ROS normally present at physiological conditions that are required for optimal cellular functioning. This review aims to examine the double-edged effects of dietary originating antioxidants with a focus on the most abundant compounds, especially polyphenols, vitamin C, vitamin E and carotenoids. Different approaches to enrich our body with exogenous antioxidants such as via synthetic antioxidants, diets rich in fruits and vegetables and taking supplements will be reviewed and experimental and epidemiological evidences discussed, highlighting that antioxidants at physiological doses are generally safe, exhibiting interesting health beneficial effects.
873 citations
TL;DR: The mechanism occurs by a complex sequence of events including: (1) CYP metabolism to a reactive metabolite which depletes glutathione and covalently binds to proteins; (2) loss of glutathion with an increased formation of reactive oxygen and nitrogen species in hepatocytes undergoing necrotic changes; (3) increased oxidative stress, associated with alterations in calcium homeostasis and initiation of signal transduction responses, causing mitochondrial permeability transition; (4) mitochondrial membrane potential, and loss of the ability of the mitochondria to synthesize ATP; and
Abstract: Although considered safe at therapeutic doses, at higher doses, acetaminophen produces a centrilobular hepatic necrosis that can be fatal. Acetaminophen poisoning accounts for approximately one-half of all cases of acute liver failure in the United States and Great Britain today. The mechanism occurs by a complex sequence of events. These events include: (1) CYP metabolism to a reactive metabolite which depletes glutathione and covalently binds to proteins; (2) loss of glutathione with an increased formation of reactive oxygen and nitrogen species in hepatocytes undergoing necrotic changes; (3) increased oxidative stress, associated with alterations in calcium homeostasis and initiation of signal transduction responses, causing mitochondrial permeability transition; (4) mitochondrial permeability transition occurring with additional oxidative stress, loss of mitochondrial membrane potential, and loss of the ability of the mitochondria to synthesize ATP; and (5) loss of ATP which leads to necrosis. Associated with these essential events there appear to be a number of inflammatory mediators such as certain cytokines and chemokines that can modify the toxicity. Some have been shown to alter oxidative stress, but the relationship of these modulators to other critical mechanistic events has not been well delineated. In addition, existing data support the involvement of cytokines, chemokines, and growth factors in the initiation of regenerative processes leading to the reestablishment of hepatic structure and function.
754 citations
TL;DR: Results demonstrated that as a unique p53 target gene, GLS2 is a mediator of p53’s role in energy metabolism and antioxidant defense, which can contribute to its role in tumor suppression.
Abstract: Whereas cell cycle arrest, apoptosis, and senescence are traditionally thought of as the major functions of the tumor suppressor p53, recent studies revealed two unique functions for this protein: p53 regulates cellular energy metabolism and antioxidant defense mechanisms. Here, we identify glutaminase 2 (GLS2) as a previously uncharacterized p53 target gene to mediate these two functions of the p53 protein. GLS2 encodes a mitochondrial glutaminase catalyzing the hydrolysis of glutamine to glutamate. p53 increases the GLS2 expression under both nonstressed and stressed conditions. GLS2 regulates cellular energy metabolism by increasing production of glutamate and α-ketoglutarate, which in turn results in enhanced mitochondrial respiration and ATP generation. Furthermore, GLS2 regulates antioxidant defense function in cells by increasing reduced glutathione (GSH) levels and decreasing ROS levels, which in turn protects cells from oxidative stress (e.g., H2O2)-induced apoptosis. Consistent with these functions of GLS2, the activation of p53 increases the levels of glutamate and α-ketoglutarate, mitochondrial respiration rate, and GSH levels and decreases reactive oxygen species (ROS) levels in cells. Furthermore, GLS2 expression is lost or greatly decreased in hepatocellular carcinomas and the overexpression of GLS2 greatly reduced tumor cell colony formation. These results demonstrated that as a unique p53 target gene, GLS2 is a mediator of p53’s role in energy metabolism and antioxidant defense, which can contribute to its role in tumor suppression.
707 citations
TL;DR: H(2)S enhances the transport of cysteine to increase GSH production more than cystine transport and to redistribute the localization of GSH to mitochondria and provides a new mechanism of neuroprotection from oxidative stress by H( 2)S.
Abstract: Hydrogen sulfide (H(2)S) is a synaptic modulator as well as a neuroprotectant in the brain. We recently showed that H(2)S protects neurons from oxidative stress by increasing the levels of glutathione (GSH), a major cellular antioxidant, by more than twice that of a control through enhancing the cystine transport. Here we show that H(2)S enhances the transport of cysteine to increase GSH production more than cystine transport and to redistribute the localization of GSH to mitochondria. The efficiency of GSH production enhanced by H(2)S is even greater by fourfold under oxidative stress by glutamate. H(2)S reinstated GSH levels in the fetal brain decreased by ischemia/reperfusion in utero. In addition, Neuro2a cells expressing a mitochondrial H(2)S-producing enzyme, 3-mercaptopyruvate sulfurtransferase (3MST), along with cysteine aminotransferase (CAT), showed significant resistance to oxidative stress. The present study shows that H(2)S protects cells from oxidative stress by two mechanisms. It enhances the production of GSH by enhancing cystine/cysteine transporters and redistributes GSH to mitochondria. H(2)S produced in mitochondria also may directly suppress oxidative stress. It provides a new mechanism of neuroprotection from oxidative stress by H(2)S.
596 citations
TL;DR: The results provide evidence for a unique metabolic role for p53, linking glutamine metabolism, energy, and ROS homeostasis, which may contribute to p53 tumor suppressor function.
Abstract: We identified a p53 target gene, phosphate-activated mitochondrial glutaminase (GLS2), a key enzyme in conversion of glutamine to glutamate, and thereby a regulator of glutathione (GSH) synthesis and energy production. GLS2 expression is induced in response to DNA damage or oxidative stress in a p53-dependent manner, and p53 associates with the GLS2 promoter. Elevated GLS2 facilitates glutamine metabolism and lowers intracellular reactive oxygen species (ROS) levels, resulting in an overall decrease in DNA oxidation as determined by measurement of 8-OH-dG content in both normal and stressed cells. Further, siRNA down-regulation of either GLS2 or p53 compromises the GSH-dependent antioxidant system and increases intracellular ROS levels. High ROS levels following GLS2 knockdown also coincide with stimulation of p53-induced cell death. We propose that GLS2 control of intracellular ROS levels and the apoptotic response facilitates the ability of p53 to protect cells from accumulation of genomic damage and allows cells to survive after mild and repairable genotoxic stress. Indeed, overexpression of GLS2 reduces the growth of tumor cells and colony formation. Further, compared with normal tissue, GLS2 expression is reduced in liver tumors. Thus, our results provide evidence for a unique metabolic role for p53, linking glutamine metabolism, energy, and ROS homeostasis, which may contribute to p53 tumor suppressor function.
568 citations
TL;DR: It is shown that eNOS S-glutathionylation in endothelial cells, with loss of NO and gain of O2•− generation, is associated with impaired endothelium-dependent vasodilation and is a pivotal switch providing redox regulation of cellular signalling, endothelial function and vascular tone.
Abstract: Endothelial nitric oxide synthase (eNOS) is critical in the regulation of vascular function, and can generate both nitric oxide (NO) and superoxide (O(2)(•-)), which are key mediators of cellular signalling In the presence of Ca(2+)/calmodulin, eNOS produces NO, endothelial-derived relaxing factor, from l-arginine (l-Arg) by means of electron transfer from NADPH through a flavin containing reductase domain to oxygen bound at the haem of an oxygenase domain, which also contains binding sites for tetrahydrobiopterin (BH(4)) and l-Arg In the absence of BH(4), NO synthesis is abrogated and instead O(2)(•-) is generated While NOS dysfunction occurs in diseases with redox stress, BH(4) repletion only partly restores NOS activity and NOS-dependent vasodilation This suggests that there is an as yet unidentified redox-regulated mechanism controlling NOS function Protein thiols can undergo S-glutathionylation, a reversible protein modification involved in cellular signalling and adaptation Under oxidative stress, S-glutathionylation occurs through thiol-disulphide exchange with oxidized glutathione or reaction of oxidant-induced protein thiyl radicals with reduced glutathione Cysteine residues are critical for the maintenance of eNOS function; we therefore speculated that oxidative stress could alter eNOS activity through S-glutathionylation Here we show that S-glutathionylation of eNOS reversibly decreases NOS activity with an increase in O(2)(•-) generation primarily from the reductase, in which two highly conserved cysteine residues are identified as sites of S-glutathionylation and found to be critical for redox-regulation of eNOS function We show that eNOS S-glutathionylation in endothelial cells, with loss of NO and gain of O(2)(•-) generation, is associated with impaired endothelium-dependent vasodilation In hypertensive vessels, eNOS S-glutathionylation is increased with impaired endothelium-dependent vasodilation that is restored by thiol-specific reducing agents, which reverse this S-glutathionylation Thus, S-glutathionylation of eNOS is a pivotal switch providing redox regulation of cellular signalling, endothelial function and vascular tone
482 citations
TL;DR: Oxidative stress was more localized to the synapses, with levels increasing in a disease-dependent fashion, which implicate an involvement of oxidative stress in Alzheimer disease-related synaptic loss.
Abstract: We investigated oxidative stress in human postmortem frontal cortexfrom individuals characterized as mild cognitive impairment (n= 8), mild/moderate Alzheimer disease (n = 4), and late-stage Alzheimer disease (n = 9). Samples from subjects with no cognitive impairment (n = 10) that were age- and postmortem interval-matched with these cases were used as controls. The short postmortem intervalbrain samples were processed for postmitochondrial supernatant, nonsynaptic mitochondria, and synaptosome fractions. Samples were analyzed for several antioxidants (glutathione, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, glucose-6-phosphate dehydrogenase, superoxide dismutase, catalase) and the oxidative marker, thiobarbituric acid reactive substances. The tissue was also analyzed for possible changes in protein damage using neurochemical markers for protein carbonyls, 3-nitrotyrosine, 4-hydroxynonenal, andacrolein. All 3 neuropil fractions (postmitochondrial supernatant, mitochondrial, and synaptosomal) demonstrated significant disease-dependent increases in oxidative markers. The highest changes were observed in the synaptosomal fraction. Both mitochondrial and synaptosomal fractions had significant declines in antioxidants (glutathione, glutathione peroxidase, glutathione-S-transferase, and superoxide dismutase). Levels of oxidative markers significantly correlated with Mini-Mental Status Examination scores. Oxidative stress was more localized to the synapses, with levels increasing in a disease-dependent fashion. These correlations implicate an involvement of oxidative stress in Alzheimer disease-related synaptic loss.
TL;DR: The hepatotoxicity of AgNPs was assessed in the liver of adult zebrafish, and data suggest that oxidative stress and apoptosis are associated with AgNP toxicity in the Liver of adultZebrafish.
TL;DR: The critical role of Nrf2 has been demonstrated by various animal studies showing that mice with a targeted disruption of the nrf2 gene are prone to develop lesions in response to environmental toxicants/carcinogens, drugs, and inflammatory insults and the potential pleiotropic effects of NRF2 activation of indirect antioxidants.
Abstract: Oxidative stress causes damage to multiple cellular components such as DNA, proteins, and lipids, and is implicated in various human diseases including cancer, neurodegeneration, inflammatory diseases, and aging. In response to oxidative attack, cells have developed an antioxidant defense system to maintain cellular redox homeostasis and to protect cells from damage. The thiol-containing small molecules (e.g. glutathione), reactive oxygen species-inactivating enzymes (e.g. glutathione peroxidase), and phase 2 detoxifying enzymes (e.g. NAD(P)H: quinine oxidoreductase 1 and glutathione-S-transferases) are members of this antioxidant system. NF-E2-related factor 2 (Nrf2) is a CNC-bZIP transcription factor which regulates the basal and inducible expression of a wide array of antioxidant genes. Following dissociation from the cytosolic protein Keap1, a scaffolding protein which binds Nrf2 and Cul3 ubiquitin ligase for proteasome degradation, Nrf2 rapidly accumulates in the nucleus and transactivates the antioxidant response element in the promoter region of many antioxidant genes. The critical role of Nrf2 has been demonstrated by various animal studies showing that mice with a targeted disruption of the nrf2 gene are prone to develop lesions in response to environmental toxicants/carcinogens, drugs, and inflammatory insults. In this review, we discuss the role of the Nrf2 system, with particular focus on Nrf2-controlled target genes and the potential pleiotropic effects of Nrf2 activation of indirect antioxidants.
TL;DR: The amino acid composition and antioxidant activities of peptide fractions obtained from HPLC separation of a pea protein hydrolysate (PPH) were studied and glutathione had significantly higher (p < 0.05) ability to inhibit linoleic acid oxidation and chelate metals.
Abstract: The amino acid composition and antioxidant activities of peptide fractions obtained from HPLC separation of a pea protein hydrolysate (PPH) were studied. Thermolysin hydrolysis of pea protein isolate and ultrafiltration (3 kDa molecular weight cutoff membrane) yielded a PPH that was separated into five fractions (F1−F5) on a C18 reverse phase HPLC column. The fractions that eluted later from the column (F3−F5) contained higher contents hydrophobic and aromatic amino acids when compared to fractions that eluted early or the original PPH. Fractions F3−F5 also exhibited the strongest radical scavenging and metal chelating activities; however, hydrophobic character did not seem to contribute to reducing power of the peptides. In comparison to glutathione, the peptide fractions had significantly higher (p < 0.05) ability to inhibit linoleic acid oxidation and chelate metals. In contrast, glutathione had significantly higher (p < 0.05) free radical scavenging properties than the peptide fractions.
TL;DR: This review summarizes recent findings in the field to address the potential mechanism whereby oxidative stress mediates fibrogenesis induced by TGF-beta and the potential therapeutic value of antioxidant treatment in fibrotic diseases.
TL;DR: Delayed treatment with GSH and NAC protect against APAP overdose by dual mechanisms—that is, by enhancing hepatic and mitochondrial GSH levels (scavenging of reactive oxygen and peroxynitrite)—and by supporting the mitochondrial energy metabolism.
TL;DR: Inhibition of AChE showed that RD acts as a contaminant with anti-AChE action, which stimulated the biotransformation pathway, with increased GST, but interfered on the antioxidant defenses, with reduction of SOD and GPx activity, leading to the occurrence of lipid peroxidation.
TL;DR: It is proposed that KEAP1 intermolecular disulfide formation via Cys151 underlies the activation of NRF2 by reactive oxygen and nitrogen species.
TL;DR: It is suggested that both betaine and proline provide a protective action against Cd-induced oxidative stress by reducing H2O2 and lipid peroxidation levels and by increasing the antioxidant defense and MG detoxification systems.
Abstract: The present study investigates the possible mediatory role of exogenously applied glycinebetaine (betaine) and proline on reactive oxygen species (ROS) and methylglyoxal (MG) detoxification systems in mung bean seedlings subjected to cadmium (Cd) stress (1 mM CdCl2, 48 h). Cadmium stress caused a significant increase in glutathione (GSH) and glutathione disulfide (GSSG) content, while the ascorbate (AsA) content decreased significantly with a sharp increase in hydrogen peroxide (H2O2) and lipid peroxidation level (MDA). Ascorbate peroxidase (APX), glutathione S-transferase (GST), glutathione peroxidase (GPX), and glyoxalase I (Gly I) activities were increased in response to Cd stress, while the activities of catalase (CAT), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR) and glyoxalase II (Gly II) were sharply decreased. Exogenous application of 5 mM betaine or 5 mM proline resulted in an increase in GSH and AsA content, maintenance of a high GSH/GSSG ratio and increased the activities of APX, DHAR, MDHAR, GR, GST, GPX, CAT, Gly I and Gly II involved in ROS and MG detoxification system as compared to the control and mostly also Cd-stressed plants, with a concomitant decrease in GSSG content, H2O2 and lipid peroxidation level. These findings together with our earlier findings suggest that both betaine and proline provide a protective action against Cd-induced oxidative stress by reducing H2O2 and lipid peroxidation levels and by increasing the antioxidant defense and MG detoxification systems.
TL;DR: It is concluded that GR1 plays a crucial role in daylength-dependent redox signaling and that this function cannot be replaced by the second Arabidopsis GR gene or by thiol systems such as the thioredoxin system.
Abstract: Glutathione is a major cellular thiol that is maintained in the reduced state by glutathione reductase (GR), which is encoded by two genes in Arabidopsis (Arabidopsis thaliana; GR1 and GR2). This study addressed the role of GR1 in hydrogen peroxide (H(2)O(2)) responses through a combined genetic, transcriptomic, and redox profiling approach. To identify the potential role of changes in glutathione status in H(2)O(2) signaling, gr1 mutants, which show a constitutive increase in oxidized glutathione (GSSG), were compared with a catalase-deficient background (cat2), in which GSSG accumulation is conditionally driven by H(2)O(2). Parallel transcriptomics analysis of gr1 and cat2 identified overlapping gene expression profiles that in both lines were dependent on growth daylength. Overlapping genes included phytohormone-associated genes, in particular implicating glutathione oxidation state in the regulation of jasmonic acid signaling. Direct analysis of H(2)O(2)-glutathione interactions in cat2 gr1 double mutants established that GR1-dependent glutathione status is required for multiple responses to increased H(2)O(2) availability, including limitation of lesion formation, accumulation of salicylic acid, induction of pathogenesis-related genes, and signaling through jasmonic acid pathways. Modulation of these responses in cat2 gr1 was linked to dramatic GSSG accumulation and modified expression of specific glutaredoxins and glutathione S-transferases, but there is little or no evidence of generalized oxidative stress or changes in thioredoxin-associated gene expression. We conclude that GR1 plays a crucial role in daylength-dependent redox signaling and that this function cannot be replaced by the second Arabidopsis GR gene or by thiol systems such as the thioredoxin system.
TL;DR: The present study suggested that naringenin may be beneficial in ameliorating the cadmium-induced oxidative damage in the liver of rats.
TL;DR: Measuring the GSH/GSSG ratio in pathological tissues and experimental models thereof in comparison to the results in controls is an excellent way to assess potential therapeutics efficacy in maintaining cellular redox potential.
Abstract: Glutathione (GSH) is the most abundant antioxidant in aerobic cells, present in micromolar (microM)-concentrations in bodily fluids and in millimolar (mM) concentrations in tissue. GSH is critical for protecting the brain from oxidative stress, acting as a free radical scavenger and inhibitor of lipid peroxidation. GSH also participates in the detoxification of hydrogen peroxide by various glutathione peroxidases. The ratio of reduced GSH to oxidized GSH (GSSG) is an indicator of cellular health, with reduced GSH constituting up to 98% of cellular GSH under normal conditions. However, the GSH/GSSG ratio is reduced in neurodegenerative diseases, such as Parkinson's disease (PD) and Alzheimer's disease (AD). Measuring the GSH/GSSG ratio in pathological tissues and experimental models thereof in comparison to the results in controls is an excellent way to assess potential therapeutics efficacy in maintaining cellular redox potential. The availability of UV/Visible instruments equipped with 96-well plate readers as common laboratory equipment has made measuring the GSH/GSSG ratio on multiple samples a manageable procedure.
TL;DR: This study shows that these pathways interfere with auxin transport and metabolism, defining a link between redox regulation and auxin signaling, and associates TRX reductases (ntra ntrb) and glutathione biosynthesis (cad2) mutations with these two thiol reduction pathways.
Abstract: Intracellular redox status is a critical parameter determining plant development in response to biotic and abiotic stress. Thioredoxin (TRX) and glutathione are key regulators of redox homeostasis, and the TRX and glutathione pathways are essential for postembryonic meristematic activities. Here, we show by associating TRX reductases (ntra ntrb) and glutathione biosynthesis (cad2) mutations that these two thiol reduction pathways interfere with developmental processes through modulation of auxin signaling. The triple ntra ntrb cad2 mutant develops normally at the rosette stage, undergoes the floral transition, but produces almost naked stems, reminiscent of the phenotype of several mutants affected in auxin transport or biosynthesis. In addition, the ntra ntrb cad2 mutant shows a loss of apical dominance, vasculature defects, and reduced secondary root production, several phenotypes tightly regulated by auxin. We further show that auxin transport capacities and auxin levels are perturbed in the mutant, suggesting that the NTR-glutathione pathways alter both auxin transport and metabolism. Analysis of ntr and glutathione biosynthesis mutants suggests that glutathione homeostasis plays a major role in auxin transport as both NTR and glutathione pathways are involved in auxin homeostasis.
TL;DR: Investigation of gold(I) complexes with benzimidazole derived N-heterocyclic carbene (NHC) ligands represent a promising class of gold coordination compounds with a good stability against the thiol glutathione.
Abstract: Gold(I) complexes such as auranofin have been used for decades to treat symptoms of rheumatoid arthritis and have also demonstrated a considerable potential as new anticancer drugs. The enzyme thioredoxin reductase (TrxR) is considered as the most relevant molecular target for these species. The here investigated gold(I) complexes with benzimidazole derived N-heterocyclic carbene (NHC) ligands 1a−4a represent a promising class of gold coordination compounds with a good stability against the thiol glutathione. TrxR was selectively inhibited by 1a−4a in comparison to the closely related enzyme glutathione reductase, and all complexes triggered significant antiproliferative effects in cultured tumor cells. More detailed studies on a selected complex (2a) revealed a distinct pharmacodynamic profile including the high increase of reactive oxygen species formation, apoptosis induction, strong effects on cellular metabolism (related to cell surface properties, respiration, and glycolysis), inhibition of mitochon...
TL;DR: A scheme for the mechanism of the conversion is proposed in which the formation of PGE1 as well as that of the byproducts is assumed to occur on the enzyme in concerted reactions via peroxy-radicals and a cyclic peroxide as mentioned in this paper.
Abstract: In the biosynthesis of prostaglandin E1 (PGE1) with an enzyme fraction of sheep vesicular glands glutathione and a moderate amount of antioxidant are required to obtain maximum yield; two oxygen molecules are consumed per mole PGE1 formed. By altering the incubation conditions, besides PGE1 various other products can be obtained.
A scheme for the mechanism of the conversion is proposed in which the formation of PGE1 as well as that of the byproducts is assumed to occur on the enzyme in concerted reactions via peroxy-radicals and a cyclic peroxide.
TL;DR: Results suggest that both ascorbate and glutathione homeostasis can be considered as biomarkers for salt tolerance in Pokkali rice and status of reactive oxygen species and oxidative DNA damage can serve as a quick and sensitive biomarker for screening against salt and other abiotic stresses in crop plants.
Abstract: To identify biochemical markers for salt tolerance, two contrasting cultivars of rice (Oryza sativa L.) differing in salt tolerance were analyzed for various parameters. Pokkali, a salt-tolerant cultivar, showed considerably lower level of H(2)O(2) as compared to IR64, a sensitive cultivar, and such a physiology may be ascribed to the higher activity of enzymes in Pokkali, which either directly or indirectly are involved in the detoxification of H(2)O(2). Enzyme activities and the isoenzyme pattern of antioxidant enzymes also showed higher activity of different types and forms in Pokkali as compared to IR64, suggesting that Pokkali possesses a more efficient antioxidant defense system to cope up with salt-induced oxidative stress. Further, Pokkali exhibited a higher GSH/GSSG ratio along with a higher ratio of reduced ascorbate/oxidized ascorbate as compared to IR64 under NaCl stress. In addition, the activity of methylglyoxal detoxification system (glyoxalase I and II) was significantly higher in Pokkali as compared to IR64. As reduced glutathione is involved in the ascorbate-glutathione pathway as well as in the methylglyoxal detoxification pathway, it may be a point of interaction between these two. Our results suggest that both ascorbate and glutathione homeostasis, modulated also via glyoxalase enzymes, can be considered as biomarkers for salt tolerance in Pokkali rice. In addition, status of reactive oxygen species and oxidative DNA damage can serve as a quick and sensitive biomarker for screening against salt and other abiotic stresses in crop plants.
TL;DR: It can be concluded that concomitant administration of quercetin or curcumin with paracetamol may be useful in reversing the toxicity of the drug compared to N-acetylcysteine.
TL;DR: RES was found to be successful in upregulating the antioxidant status and lowering the dopamine loss, and the elevated level of thiobarbituric acid reactive substances (TBARS), protein carbonyl (PC), and activity of phospholipase A2 in 6-OHDA group was attenuated significantly in RES-pretreated group when compared with 6- OHDA-lesioned group.
TL;DR: E elevated intracellular GSH and stimulated APX (especially cAPX, sAPX and tAPX iosenzymes) and CAT activities play an important role in GSH-induced alleviation of oxidative stress.
TL;DR: A high level of GSH in the nucleus may not only have an immediate effect on gene expression patterns, but also contribute to how cells retain a memory of the cellular redox environment that is transferred through generations.
Abstract: The complex antioxidant network of plant and animal cells has the thiol tripeptide GSH at its centre to buffer ROS (reactive oxygen species) and facilitate cellular redox signalling which controls growth, development and defence GSH is found in nearly every compartment of the cell, including the nucleus Transport between the different intracellular compartments is pivotal to the regulation of cell proliferation GSH co-localizes with nuclear DNA at the early stages of proliferation in plant and animal cells Moreover, GSH recruitment and sequestration in the nucleus during the G1- and S-phases of the cell cycle has a profound impact on cellular redox homoeostasis and on gene expression For example, the abundance of transcripts encoding stress and defence proteins is decreased when GSH is sequestered in the nucleus The functions of GSHn (nuclear GSH) are considered in the present review in the context of whole-cell redox homoeostasis and signalling, as well as potential mechanisms for GSH transport into the nucleus We also discuss the possible role of GSHn as a regulator of nuclear proteins such as histones and PARP [poly(ADP-ribose) polymerase] that control genetic and epigenetic events In this way, a high level of GSH in the nucleus may not only have an immediate effect on gene expression patterns, but also contribute to how cells retain a memory of the cellular redox environment that is transferred through generations