GSH Reductase Activity Research Articles

The Effects of Co-Exposure to Antifoulants and Microplastics on the Survival, Oxidative Status, and Cholinergic System of a Marine Mysid.

Antifoulants such as copper pyrithione (CuPT) and zinc pyrithione (ZnPT) are widespread and hazardous pollutants in aquatic environments. The presence of microplastics (MPs) introduces significant uncertainty regarding the toxicity of CuPT and ZnPT, as their effects can be influenced by MPs. There is a limited understanding of the toxic potential of CuPT and ZnPT when they coexist with MPs. Here, the marine mysid Neomysis awatchensis was treated using no observed effect concentration (NOEC) values of CuPT and ZnPT premixed with MPs (1 µm; 1-100 particles mL-1). The presence of MPs increased the toxicity of the antifoulants in juvenile and adult mysids over 96 h. The additive effect of the MPs varied by chemical; feeding was only reduced by CuPT with MPs, whereas no fluctuation in feeding was observed in response to ZnPT with MPs. Co-exposure to antifoulants and MPs increased malonaldehyde levels, but the response of antioxidant components varied by chemical. In mysids co-exposed to CuPT and MPs, the activity levels of catalase and superoxide dismutase were decreased, whereas their enzymatic activity levels were elevated by co-exposure to ZnPT and MPs. Similarly, depletion of glutathione (GSH) was observed in mysids co-exposed to CuPT and MPs, with significant reductions in GSH reductase (GR) and peroxidase (GPx). However, the GSH level was increased by co-exposure to ZnPT and MPs, with elevations in GR and GPx activity levels. Significant inhibition of acetylcholinesterase activity was only observed in response to CuPT and MPs. These results suggest that MPs can increase toxicity via additive and/or synergistic effects through oxidative imbalance, but these effects of MPs can vary with different chemicals.

Sex-specific interactions between stress axis and redox balance are associated with internalizing symptoms and brain white matter microstructure in adolescents

Adolescence is marked by the maturation of systems involved in emotional regulation and by an increased risk for internalizing disorders (anxiety/depression), especially in females. Hypothalamic-pituitary-adrenal (HPA)-axis function and redox homeostasis (balance between reactive oxygen species and antioxidants) have both been associated with internalizing disorders and may represent critical factors for the development of brain networks of emotional regulation. However, sex-specific interactions between these factors and internalizing symptoms and their link with brain maturation remain unexplored. We investigated in a cohort of adolescents aged 13–15 from the general population (n = 69) whether sex-differences in internalizing symptoms were associated with the glutathione (GSH)-redox cycle homeostasis and HPA-axis function and if these parameters were associated with brain white matter microstructure development. Female adolescents displayed higher levels of internalizing symptoms, GSH-peroxidase (GPx) activity and cortisol/11-deoxycortisol ratio than males. There was a strong correlation between GPx and GSH-reductase (Gred) activities in females only. The cortisol/11-deoxycortisol ratio, related to the HPA-axis activity, was associated with internalizing symptoms in both sexes, whereas GPx activity was associated with internalizing symptoms in females specifically. The cortisol/11-deoxycortisol ratio mediated sex-differences in internalizing symptoms and the association between anxiety and GPx activity in females specifically. In females, GPx activity was positively associated with generalized fractional anisotropy in widespread white matter brain regions. We found that higher levels of internalizing symptoms in female adolescents than in males relate to sex-differences in HPA-axis function. In females, our results suggest an important interplay between HPA-axis function and GSH-homeostasis, a parameter strongly associated with brain white matter microstructure.

Immobilized doxorubicin and ribociclib carbamate linkers encaged in surface modified cubosomes spatially target tumor reductive environment to enhance antitumor efficacy

In the present investigation, we have strategically synthesized Glutathione (GSH) stimuli-sensitive analogues using carbamate linkers (CL) of DOX (DOX-CL) and RB (RB-CL) which were then anchored to gold nanoparticles (Au-DOX-CL, Au-RB-CL) using mPEG as a spacer. It was observed that carbamate linkage (CL) with four carbon spacer is critical, to position the terminal thiol group, to access the carbamate group efficiently to achieve GSH-assisted release of DOX and RB in tumor-specific environment. When assessed for GSH reductase activity in MDA-MB 231 cell lines, Au-DOX-CL and Au-RB-CL showed nearly 4.18 and 3.13 fold higher GSH reductive activity as compared to the control group respectively. To achieve spatial tumor targeting with a high payload of DOX and RB, Au-DOX-CL and Au-RB-CL were encapsulated in the cell-penetrating peptide (CPP) modified liquid crystalline cubosomes i.e. CPP-Cu(Au@CL-DR). After internalization, the prototype nanocarriers release respective drugs at a precise GSH concentration inside the tumor tissues, amplifying drug concentration to a tune of five-fold. The drug concentrations remain within the therapeutic window for 72 h with a significant reduction of RB (7.8-fold) and DOX (6-fold) concentrations in vital organs, rendering reduced toxicity and improved survival. Overall, this constitutes a promising chemotherapeutic strategy against cancer and its potential application in the offing.

Selenite Bioremediation by Food-Grade Probiotic Lactobacillus casei ATCC 393: Insights from Proteomics Analysis.

Microorganisms capable of converting toxic selenite into elemental selenium (Se0) are considered an important and effective approach for bioremediation of Se contamination. In this study, we investigated the mechanism of reducing selenite to Se0 and forming Se nanoparticles (SeNPs) by food-grade probiotic Lactobacillus casei ATCC 393 (L. casei ATCC 393) through proteomics analysis. The results showed that selenite added during the exponential growth period of bacteria has the highest reduction efficiency, and 4.0 mM selenite decreased by nearly 95% within 72 h and formed protein-capped-SeNPs. Proteomics analysis revealed that selenite induced a significant increase in the expression of glutaredoxin, oxidoreductase, and ATP binding cassette (ABC) transporter, which can transport glutathione (GSH) and selenite. Selenite treatment significantly increased the CydC and CydD (putative cysteine and glutathione importer, ABC transporter) mRNA expression level, GSH content, and GSH reductase activity. Furthermore, supplementation with an additional GSH significantly increased the reduction rate of selenite, while GSH depletion significantly inhibited the reduction of selenite, indicating that GSH-mediated Painter-type reaction may be the main pathway of selenite reduction in L. casei ATCC 393. Moreover, nitrate reductase also participates in the reduction process of selenite, but it is not the primary factor. Overall, L. casei ATCC 393 effectively reduced selenite to SeNPs by GSH and nitrate reductase-mediated reduction pathway, and the GSH pathway played the decisive role, which provides an environmentally friendly biocatalyst for the bioremediation of Se contamination. IMPORTANCE Due to the high solubility and bioavailability of selenite, and its widespread use in industrial and agricultural production, it is easy to cause selenite to accumulate in the environment and reach toxic levels. Although the bacteria screened from special environments have high selenite tolerance, their safety has not been fully verified. It is necessary to screen out strains with selenite-reducing ability from nonpathogenic, functionally known, and widely used strains. Herein, we found food-grade probiotic L. casei ATCC 393 effectively reduced selenite to SeNPs by GSH and nitrate reductase-mediated reduction pathway, which provides an environmentally friendly biocatalyst for the bioremediation of Se contamination.

Physiological and Antioxidant Response to Different Water Deficit Regimes of Flag Leaves and Ears of Wheat Grown under Combined Elevated CO2 and High Temperature.

Triticum aestivum L. cv. Gazul is a spring wheat widely cultivated in Castilla y León (Spain). Potted plants were grown in a scenario emulating the climate change environmental conditions expected by the end of this century, i.e., with elevated CO2 and high temperature under two water deficit regimes: long (LWD) and terminal (TWD). Changes in biomass and morphology, the content of proline (Pro), ascorbate (AsA) and glutathione (GSH), and enzymatic antioxidant activities were analyzed in flag leaves and ears. Additionally, leaf gas exchange was measured. LWD caused a decrease in biomass and AsA content but an increase in Pro content and catalase and GSH reductase activities in flag leaves, whereas TWD produced no significant changes. Photosynthesis was enhanced under both water deficit regimes. Increase in superoxide dismutase activity and Pro content was only observed in ears under TWD. The lack of a more acute effect of LWD and TWD on both organs was attributed to the ROS relieving effect of elevated CO2. Gazul acted as a drought tolerant variety with anisohydric behavior. A multifactorial analysis showed better adaptation of ears to water deficit than flag leaves, underlining the importance of this finding for breeding programs to improve grain yield under future climate change.

Deficiency in glutathione synthesis and reduction contributes to the pathogenesis of colitis-related liver injury.

Liver disease is the most common extra-intestinal manifestation of ulcerative colitis (UC), but the underlying pathogenesis is still not clarified. It is well accepted that the occurrence of UC-related liver disease has close correlation with immune activation, intestinal bacterial liver translocation, inflammatory cytokine storm, and the disturbance of bile acid circulation. The occurrence of UC-related liver disease makes the therapy difficult, therefor study on the pathogenesis of UC-related liver injury is of great significance for its prevention and treatment. Glutathione (GSH) shows multiple physiological activities, such as free radical scavenging, detoxification metabolism and immune defense. The synthesis and the oxidation-reduction all contribute to GSH antioxidant function. It is reported that the deficiency in hepatic GSH antioxidant function participates in multiple liver diseases, but whether it participates in the pathogenesis of UC-related liver injury is still not clear. This study aims to investigate the feature and underlying mechanism of GSH synthesis and oxidation-reduction function during the development of UC, which will provide useful information for the pathogenesis study on UC-related liver injury. UC model was induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS)-ethanol solution (5 mg/0.8 mL per rat, 50% ethanol) via intra-colonic administration in rats, and the samples of serum, liver, and colon tissue of rats were collected at the 3rd, 5th, and 7th days post TNBS. The severity degree of colitis was evaluated by measuring the disease activity index, colonic myeloperoxidase activity, and histopathological score, and the degree of liver injury was evaluated by histopathological score and the serum content of alanine aminotransferase. Spearman correlation analysis was also conducted between the degree of colonic lesions and index of hepatic histopathological score as well as serum aspartate aminotransferase level to clarify the correlation between liver injury and colitis. To evaluate the hepatic antioxidant function of GSH in UC rats, hepatic GSH content, enzyme activity of GSH peroxidase (GSH-Px), and GSH reductase (GR) were determined in rats at the 3rd, 5th, and 7th days post TNBS, and the protein expressions of glutamine cysteine ligase (GCL), GSH synthase, GSH-Px, and GR in the liver of UC rats were also examined by Western blotting. Compared with the control, the disease activity index, colonic myeloperoxidase activity, and histopathological score were all significantly increased at the 3rd, 5th, and 7th days post TNBS (all P<0.01), the serum aspartate aminotransferase level and hepatic histopathologic score were also obviously elevated at the 7th day post TNBS (all P<0.05). There was a significant positive correlation between the degree of liver injury and the severity of colonic lesions (P=0.000 1). Moreover, compared with the control, hepatic GSH content and the activity of GSH-Px and GR were all significantly decreased at the 3rd and 5th days post TNBS (P<0.05 or P<0.01), and the protein expressions of GCL, GSH-Px, and GR were all obviously down-regulated at the 3rd, 5th, and 7th days post TNBS (P<0.05 or P<0.01). There is a significant positive correlation between the degree of liver injury and the severity of colonic lesions, and the occurrence of reduced hepatic GSH synthesis and decreased GSH reduction function is obviously earlier than that of the liver injury in UC rats. The reduced hepatic expression of enzymes that responsible for GSH synthesis and reduction may contribute to the deficiency of GSH synthesis and oxidation-reduction function, indicating that the deficiency in GSH antioxidant function may participate in the pathogenesis of UC related liver injury.

Coaction of hepatic thioredoxin and glutathione systems in iron overload-induced oxidative stress.

In the present study, we demonstrate the coaction of thioredoxin and glutathione (GSH) systems in mouse liver against iron overload-induced oxidative stress (OS). Mice were injected intraperitoneally with an iron dextran solution twice a week for 3 weeks. Iron accumulation in mouse liver was demonstrated spectroscopically. To confirm the iron overload model in the liver, the increased gene expression levels of hepcidin (Hamp), ferroportin (Fpn1), and ferritin (Fth1), which regulate iron trafficking, were observed by a quantitative polymerase chain reaction. In the case of iron overload, the GSHlevel and the reduced glutathione/oxidized glutathioneratio, which represents a marker of OS, decreased significantly. An increase in the malondialdehyde level, one of the final products of the lipid peroxidation process, was observed. The gene expression of the thioredoxin system, including thioredoxin (Trx1) and thioredoxin reductase (TrxR1), was examined. ThoughTrxR1 expression decreased, no changes were observed in Trx1. The enzyme activity and semiquantitative protein expression of TRXR1 increased. The activity of GSHreductase and GSH peroxidase increased in the iron overload group. The gene and protein expressions of thioredoxininteracting protein, which is an indicator of the commitment of the cell to apoptosis, were elevated significantly. The increased protein expression of Bcl-2-related X protein and CASPASE-3, which is an indicator of apoptosis, increased significantly. In conclusion, excess iron accumulation in mouse liver tissue causes OS, which affects the redox state of the thioredoxin and GSH systems, inducing cell apoptosis and also ferroptosis due to increased lipid peroxidation and the depletion of GSH level.

Attenuation of the Na/K‑ATPase/Src/ROS amplification signaling pathway by astaxanthin ameliorates myocardial cell oxidative stress injury.

The 3S, 3′S-ASTaxanthin (3S, 3′S-AST) isomer has strong antioxidant activity; however, its protective roles and potential mechanisms against oxidative stress damage in cardiomyocytes have not been investigated. Na+/K+-ATPase (NKA)/Src signal activation has an important role in increasing reactive oxygen species (ROS) production. The aim of the present study was to investigate the protective effects and mechanism of 3S, 3′S-AST on hydrogen peroxide (H2O2)-induced oxidative stress injury in H9c2 myocardial cells. The protective effects of 3S, 3′S-AST on H2O2-induced H9c2 cell injury was observed by measuring lactate dehydrogenase and creatine kinase myocardial band content, cell viability and nuclear morphology. The antioxidant effect was investigated by analyzing ROS accumulation and malondialdehyde, glutathione (GSH) peroxidase, GSH and glutathione reductase activity levels. The protein expression levels of Bax, Bcl-2, caspase-3 and cleaved caspase-3 were analyzed using western blotting to determine cardiomyocyte apoptosis. Western blot analysis of the phosphorylation levels of Src and Erk1/2 were also performed to elucidate the molecular mechanism involved. The results showed that 3S, 3′S-AST reduced the release of LDH and promoted cell viability, and attenuated ROS accumulation and cell apoptosis induced by H2O2. Furthermore, 3S, 3′S-AST also restored apoptosis-related Bax and Bcl-2 protein expression levels in H2O2-treated H9c2 cells. The phosphorylation levels of Src and Erk1/2 were significantly higher in the H2O2 treatment group, whereas 3S, 3′S-AST pretreatment significantly decreased the levels of phosphorylated (p)-Src and p-ERK1/2. The results provided evidence that 3S, 3′S-AST exhibited a cardioprotective effect against oxidative stress injury by attenuating NKA/Src/Erk1/2-modulated ROS amplification.

A stepwise control strategy for glutathione synthesis in Saccharomyces cerevisiae based on oxidative stress and energy metabolism.

A stepwise control strategy for enhancing glutathione (GSH) synthesis in yeast based on oxidative stress and energy metabolism was investigated. First, molasses and corn steep liquor were selected and fed as carbon source mixture at a flow rate of 1.5g/L/h and 0.4g/L/h, respectively, for increasing cell density in a 10 L fermenter. When the biomass reached 90g/L, the KMnO4 sustained-release particles, composed of 1.5% KMnO4, 3% stearic acid, 2% polyethylene glycol and 3% agar powder, were prepared and added to the fermentation broth for maintaining the oxidative stress. The results showed that the maximum GSH accumulation of the group fed KMnO4 sustained-release particles was 39.0% higher than that of KMnO4-fed group. In addition to the improved average GSH productivity and average specific production rate, the activities of GSH peroxidase, γ-glutamylcysteine synthetase and GSH reductase, enzymes taking part in GSH metabolism, were also significantly enhanced by KMnO4 sustained-release particles feeding. Finally, 6g/L sodium citrate fed as an energy adjuvant elevated the intracellular ATP level for further enhancing GSH production. Through the above stepwise strategy, the GSH accumulation reached 5.76g/L, which was 2.84-fold higher than that of the control group. The stepwise control strategy based on oxidative stress and energy metabolism significantly improved GSH accumulation in yeast.

The Effect of Turmeric Extract (Curcuma zedoria) on Antioxidant Enzymes Activity

Background: Indonesia is a country that has diversity of spices and types of cuisine. In the early 70s, the use of MSG (monosodium glutamate) as a flavor enhancer began to be popular in Indonesia. It replaces natural flavor such as sugar, salt or spices because its affordable price compared to natural flavor. MSG as food additive is added to foods that exceed limits and may cause a negative effect to the body. One of the effects is the increasing of free radicals that can lead to various degenerative diseases such as blood vessel disorders and others. White turmeric is a common spice that widely used by Indonesian. Several studies have reported the benefits of white turmeric as an antifungal, antimicrobial and so on. The objective of this research is to find the effects of white turmeric extract in improving endogenous antioxidants to suppress the free radical effects because of the excessive use of MSG.Materials and Method: We measured the activity of SOD, catalase and GSHreductase as endogenous antioxidants in mice treated with MSG and white turmeric. The subjects of this study used 24 Sprague Dawley male rats aged 2-6 months; weight 100-150 grams, which were randomly divided into 6 groups. The control group did not receive any treatment. The MSG group was given MSG (4800mg / kg/ day). Groups 3 and 4 were given MSG and white turmeric extract, respectively (100 mg / kg / day and 200 mg / kg / day). Groups 5 and 6 were given MSG and vitamin C respectively (250 mg / kg / day and 500 mg / kg/ day) after 14 days of treatment; the activity of enzyme measured by Abcam Enzyme Kit and detected by Spectrophotometer Thermo Scientific Multi-scan Go.Result: The administration of white turmeric extracts will increase SOD and Catalase activity, and reduce GSH-reductase activity.Conclusion: White turmeric extract will help the work of endogenous antioxidant enzymes in counteracting free radicals produced from MSG metabolism.International Journal of Human and Health Sciences Vol. 05 No. 01 January’21 Page: 31-34

Neuroprotective effect of compounds isolated from Euonymus alatus on glutamate-induced oxidative stress in HT22 hippocampal cells

Background: Euonymus alatus is used to treat diabetes in China. It is also known to have antioxidant and anti-inflammatory effects. Objectives: In this study, we isolated 10 compounds from E. alatus and confirmed that compounds whether protected neuroral cell (HT22) against glutamate induced toxicity. Materials and Methods: The n -hexane fraction of E. alatus was significantly protected HT22 cells injured by the excitotoxic amino acid, L-glutamate. We isolated ten compounds from n-hexane fraction of E. alatus , and they were identified as moretenone (1), moretenol (2), friedelanol (3), lupenone (4), β-sitosterol (5), betulin (6), undecanoic acid, 1,2-phenylene ester (7), glycerol 1-tetracosanoate (8), methyl hydrogen tetradecanedioate (9), and 10,13-nonadecadienoic acid, methyl ester (10) by spectroscopic data such as UV, IR, NMR, Mass spectroscopy. Results: Their neuroprotective activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Betulin (6) and methyl hydrogen tetradecanedioate (9) had significant neuroprotective activity against glutamate-injured HT22 cells. Furthermore, reactive oxygen species level and intracellular Ca2+ was decresed by betulin (6) and methyl hydrogen tetradecanedioate (9) and these compounds increased mitochondrial membrane potential, total glutathione (GSH) level, GSH reductase activity and GSH peroxidase activity. Conclusion: Our results suggest that betulin (6) and methyl hydrogen tetradecanedioate (9) significantly protect HT22 cells against glutamate-induced oxidative stress, through anti-oxidative activities.

Dietary glutathione supplementation enhances antioxidant activity and protects against lipopolysaccharide-induced acute hepatopancreatic injury and cell apoptosis in Chinese mitten crab, Eriocheir sinensis

Eriocheir sinensis (E. sinensis) is an important aquaculture species in China. However, deteriorating water environments lead to oxidative stress in these crabs, which subsequently reduces their quality and yield. Glutathione (GSH) is an endogenous antioxidant that is used to mitigate oxidative stress. However, whether dietary GSH can enhance the resistance of E. sinensis to oxidative stress remains unclear. Herein, crabs were fed dietary GSH (the basal diet was supplemented with 0, 300, 600, 900, and 1200 mg/kg diet weight of GSH) for up to 3 weeks and, then, challenged with lipopolysaccharide (LPS; 400 μg/kg body weight). After 6 h, their hepatopancreas were sampled. Diet supplementation with 600 and 900 mg/kg diet weight GSH not only increased the content of GSH in the hepatopancreas, but also enhanced the activities and mRNA expressions of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glutathione-S-transferase (GST) (P < 0.05), compared to that in control crabs challenged with LPS alone. Diet supplementation with 600 or 900 mg/kg GSH also significantly increased the enzyme activities of GSH reductase and γ-glutamyl cysteine synthetase (γ-GCS) in LPS-treated crabs. Haematoxylin-eosin (HE) staining, electron microscopy, and flow cytometry were used to examine the structure and subcellular structure of and apoptosis in the hepatopancreas. The histopathology and sub-microstructure analysis results also showed that diet supplementation with 600 or 900 mg/kg GSH significantly alleviated damage in crabs challenged with LPS and decreased reactive oxygen species (ROS) levels and cell apoptosis ratios in the hepatopancreas, compared to the LPS-treated crabs. To further understand the effect of dietary GSH on LPS-induced apoptosis, the activities and gene or protein expressions of apoptosis-related factors were evaluated. As a result, diet supplementation with 600 or 900 mg/kg GSH significantly decreased the activities of caspases-3, -8, and -9 and inhibited the relative expression of caspase-3 and -8 but increased the expression of B-cell lymphoma-2 (bcl-2) and B-cell lymphoma-2-associated X inhibitor (bax inhibitor) in crabs challenged with LPS. This treatment further significantly downregulated the relative protein levels of caspase-3, -8, -9 and Bax and upregulated those of Bcl-2 in crabs challenged with LPS. However, treatment with 1200 mg/kg GSH caused the opposite effects. Overall, our results reveal that appropriate diets supplemented with 600 or 900 mg/kg GSH could enhance the antioxidant capacity and anti-apoptotic mechanisms in crabs after LPS injection, thereby providing a theoretical basis for the application of dietary GSH in E. sinensis.

Soybean glycinin caused NADPH-oxidase-regulated ROS overproduction and decreased ROS elimination capacity in the mid and distal intestine of juvenile grass carp (Ctenopharyngodon idella)

Soybean glycinin could increase reactive oxygen species (ROS) content and cause damage in the intestine of Jian carp. However, related mechanisms are largely unknown. To test the hypothesis that glycinin increases intestinal ROS content by increasing ROS generation and decreasing ROS elimination capacity, juvenile grass carp (Ctenopharyngodon idella) were distributed into 3 treatments, fed with control, 8% glycinin or 8% glycinin+1.2% glutamine diets for 7 weeks, and intestinal oxidative damage, ROS content, intestinal ROS generation and elimination parameters were measured. Compared with control treatment, fish fed with glycinin diet had higher ROS, protein carbonyl (PC) and malondialdehyde (MDA) in the mid intestine (MI) and distal intestine (DI) (P < 0.05) rather than proximal intestine (PI) (P ≥ 0.05). For ROS generation parameters, compared with control treatment, dietary glycinin increased NADPH oxidase (NOX) activities, NOX1 and NOX2 protein abundance, and NOX1, NOX2, NOX organizer (NOXO) 1b, NOX activator (NOXA) 1, p47phox and p67phox mRNA abundance (P < 0.05) of MI, increased NOX activities, NOX1 protein, NOXO1b, NOXA1 and p22phox mRNA abundance (P < 0.05) of DI, and decreased NOX activities and all the mRNA abundance of NOX family genes measured (P < 0.05) except NOX4, NOXO1a and p47phox in the PI (P ≥ 0.05). For ROS elimination parameters, compared with control treatment, dietary glycinin decreased total and nuclear Nrf2 protein abundance, total antioxidant capacity (T-AOC), anti-superoxide anion (ASA), anti-hydroxy radical (AHR), CuZn-SOD, catalase, glutathione (GSH) peroxidase (GPx), GSH-S-transferase (GST) and GSH reductase (GR) activities of MI (P < 0.05), total and nuclear Nrf2 protein abundance, T-AOC, ASA, AHR, CuZn-SOD, Mn-SOD, CAT, GPx and GST activities (P < 0.05) of DI and T-AOC, ASA, CuZn-SOD, Mn-SOD and catalase activities (P < 0.05) of PI. Compared with glycinin treatment, glycinin + glutamine treatment decreased ROS, PC and MDA of MI (P < 0.05) but neither in PI nor DI of grass carp (P ≥ 0.05). Concluded, this study showed that (1) glycinin increased ROS generation related to NOX signaling pathway and decreased ROS elimination capacity related to the Nrf2 translocation in the MI and DI, which lead to the increased ROS content; (2) glycinin decreased both ROS generation and ROS elimination capacity in the PI of fish, which lead to the unchanged ROS content; (3) Glutamine could protect glycinin-induced oxidative stress mainly in the MI.

Survival of glioblastoma cells in response to endogenous and exogenous oxidative challenges: possible implication of NMDA receptor-mediated regulation of redox homeostasis.

Cancer cells are highly metabolically active and produce high levels of reactive oxygen species (ROS). Drug resistance in cancer cells is closely related to their redox status. The role of ROS and its impact on cancer cell survival seems far from elucidation. The mechanisms through which glioblastoma cells overcome aberrant ROS and oxidative stress in a milieu of hypermetabolic state is still elusive. We hypothesize that the formidable growth potential of glioma cells is through manipulation of tumor microenvironment for its survival and growth, which can be attributed to an astute redox regulation through a nexus between activation of N-methyl-d-aspartate receptor (NMDAR) and glutathione (GSH)-based antioxidant prowess. Hence, we examined the NMDAR activation on intracellular ROS level, and cell viability on exposure to hydrogen peroxide (H2 O2 ), and antioxidants in glutamate-rich microenvironment of glioblastoma. The activation of NMDAR attenuated the intracellular ROS production in LN18 and U251MG glioma cells. MK-801 significantly reversed this effect. On evaluation of GSH redox cycle in these cells, the level of reduced GSH and glutathione reductase (GR) activity were significantly increased. NMDAR significantly enhanced the cell viability in LN18 and U251MG glioblastoma cells, by attenuating exogenous H2 O2 -induced oxidative stress, and significantly increased catalase activity, the key antioxidant that detoxifies H2 O2 . We hereby report an unexplored role of NMDAR activation induced protection of the rapidly multiplying glioblastoma cells against both endogenous ROS as well as exogenous oxidative challenges. We propose potentiation of reduced GSH, GR, and catalase in glioblastoma cells through NMDAR as a novel rationale of chemoresistance in glioblastoma.

Ultrathin films of a metal-organic framework prepared from 2-methylimidazole, manganese(II) and cobalt(II) with strong oxidase-mimicking activity for colorimetric determination of glutathione and glutathione reductase activity.

Nanosheets (NSs; type ZIF-67) of a metal organic framework (MOF) that was prepared from 2-methylimidazole, manganese(II) and cobalt(II) were obtained by an ultrasonic hydrothermal method. Their Mn(II) doping reached as much as 11.3%. The NSs inherit high porosity, a large specific surface, and a large number of active sites. They display superior oxidase-mimicking activity and can catalyze the oxidation of tetramethylbenzidine (TMB) by molecular oxygen to form blue oxTMB. Glutathione (GSH) can reduce oxTMB, so that less blue oxTMB will be present. A simple and rapid method was established for the colorimetric determination of GSH and of the activity of GSH reductase (GR), best at a wavelength of 652nm. The response to GSH drops linearly in the 0.1-25μM concentration range. The activity of GR can be quantified in the 0.1 -3mU⋅mL-1 activity range. The respective detection limits are 0.07μM and 0.18mU⋅mL-1. Graphical abstract Schematic presentation of colorimetric detection of glutathione and glutathione reductase activity by theoxidase-mimicking activity of Mn-Co nanosheets in a metal organic framework.

Glutathione-redox status on hydro alcoholic root bark extract of Premna integrifolia Linn in high fat diet induced atherosclerosis model

BackgroundPremna integrifolia Linn. is a medicinal plant of an Ayurvedic importance and proved to have an anti-inflammatory, anti-diabetic, anti-microbial and hypo-lipidemic activity. Glutathione (GSH) redox status is an important parameter to assess the antioxidant activity of any neutraceuticals. ObjectiveIn order to assess the anti-oxidant potential of hydro alcoholic extract (HAE) of P. integrifolia, this study was aimed to evaluate the GSH redox status in high fat diet induced experimental atherosclerosis. Materials and methodsThe present study comprises sixty Wistar rats and they were divided into six groups: the first group served as control, the second group was fed with high fat diet and the third, fourth and fifth groups were fed with high fat diet along with various concentrations of HAE of 200, 400 and 500 g/kg.b.wt respectively and the sixth group was administered high fat diet along with 10 mg/kg b.wt of atorvastatin for 30 days. GSH-dependent enzymes like GSH-peroxidase (GPx), GSH-reductase (GR) and glucose 6-phosphate dehydrogenase (G6PD) were estimated in hemolysate, kidney, heart and liver of experimental rats. ResultsAnalysis of GSH levels showed a significant decrease in hemolysate, heart and kidney (p < 0.05) and liver (p < 0.01) in high fat-fed rats when compared to control. Activities of GPx, GR and G6PD in hemolysate and heart (p < 0.001), liver and kidney (p < 0.05) in high fat-fed rats when compared to control. Dose-dependent increase was observed in rats treated with various concentrations of HAE. ConclusionThe HAE of root bark of P. integrifolia is proved to have a protective role on antioxidant defense in high fat diet induced atherosclerosis model. As a whole P. integrifolia increases the GSH content in a dose-dependent manner and in turn altered the redox cycle.

Physiological responses of lavender (Lavandula angustifolia Mill.) towater deficit and recovery

Lavender (Lavandula angustifolia Mill.) plants were subjected to repeated water depletions and rehydration in order to evaluate the physiological responses to water deficit. The first cycle of water deprivation (WD) was induced by withholding water after sufficient irrigation; plants and soil samples were harvested 3 and 7 days after water deprivation (3 DAW and 7 DAW, respectively). The other half of the water-deprived plants were sufficiently re-watered once, and plants and soil samples were collected 3 and 10 days after re-watering (3 DAR and 10 DAR, respectively). WD produced strong decreases in leaf hydration and remarkable increases of H2O2 contents, and these changes were recovered after irrigation. Leaf hydration and hydrogen peroxide (H2O2) contents were linearly correlated to soil water contents. Abundance of δ13C gradually increased during the experiment, indicating stomatal closure. Shoot/root ratios decreased in response to WD, particularly during the second cycle of WD. Generally, total carbon (C)and total nitrogen (N)contents decreased along the experiment, whereas, total soluble sugar contents and C/N ratios kept unchanged. Total amino acid (TAA) content dramatically accumulated at the expense of soluble protein upon WD and both nitrogen fractions fully recovered after irrigation. Compared to glutathione (GSH) that slightly increased in response to WD, ascorbate contents and dehydroascorbate (DHA) reductase activities were significantly impaired by WD, but resumed after re-watering. WD and re-watering had less pronounced effects on DHA contents and GSH reductase activities. In conclusion, lavender plants responded strongly to water deficit and the physiological alterations largely recovered to previous levels after irrigation, with the exception of total C and total N contents. Thus, episodic drought events may impact growth and productivity even in plants with high resilience.

BISPHENOL A DOSE- AND TIME-DEPENDENTLY INDUCES OXIDATIVE STRESS IN RAT LIVER MITOCHONDRIA EX VIVO

Objective: The probable toxic effects of bisphenol A (BPA) on different physiological functions have been reported in animal models. The role of BPA in mitochondrial oxidative stress has not been reported till date. The present study is aimed to elucidate dose- and time-dependent oxidative stress generation by BPA, respectively, in rat liver mitochondria in ex vivo model. Methods: The incubation mixture of BPA-treated groups containing mitochondria, 50 mM potassium phosphate buffer (pH 7.4), and different concentrations of BPA (20–160 μM/ml) (dissolved in 12% DMSO) in a final volume of 1.0 ml was incubated at 37°C in incubator for different time durations (30 min–2 h). Whereas, the incubation mixture of control group contained DMSO (12%), mitochondria and 50 mM potassium phosphatebuffer (pH 7.4).’ will be replaced by ‘Whereas, the incubation mixture of control group contained the same constituents except BPA. Result: We have observed significant decrease in mitochondrial intactness incubated with BPA in dose- and time-dependent manner under bright field and confocal microscopic study compared to control. Further, we have observed a decrease in mitochondrial reduced glutathione (GSH) content and increase in lipid peroxidation and protein carbonylation levels in dose- and time-dependent manner in BPA-exposed mitochondria. We have found a significant increase in the activity of Mn-superoxide dismutase and decrease in the activities of GSH peroxidase, GSH reductase, pyruvate dehydrogenase, and other three enzymes of Kreb’s cycle dose and time dependently in BPA-exposed mitochondria. The results indicate that exposure to BPA leads to decrease in intactness of mitochondria and increase in oxidative stress in mitochondria isolated from rat liver in a dose- and time-dependent manner. Conclusion: It can be concluded that the incubation of mitochondria isolated from rat liver with BPA, caused oxidative stress-mediated damages in mitochondria in both dose- and time-dependent manners.

Aberrant GSH reductase and NOX activities concur with defective CFTR to pro-oxidative imbalance in cystic fibrosis airways.

Cystic fibrosis (CF) is associated to impaired Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) channel also causing decreased glutathione (GSH) secretion, defective airway bacterial clearance and inflammation. Here we checked the main ROS-producing and ROS-scavenging enzymes as potential additional factors involved in CF pathogenesis. We found that CFBE41o-cells, expressing F508del CFTR, have increased NADPH oxidase (NOX) activity and expression level, mainly responsible of the increased ROS production, and decreased glutathione reductase (GR) activity, not dependent on GR protein level decrease. Furthermore, defective CFTR proved to cause both extracellular and intracellular GSH level decrease, probably by reducing the amount of extracellular GSH-derived cysteine required for cytosolic GSH synthesis. Importantly, we provide evidence that defective CFTR and NOX/GR activity imbalance both contribute to NADPH and GSH level decrease and ROS overproduction in CF cells.

Hyperhomocysteinemia Alters Retinal Endothelial Cells Barrier Function and Angiogenic Potential via Activation of Oxidative Stress

Hyperhomocysteinemia (HHcy) is associated with several human visual disorders, such as diabetic retinopathy (DR) and age-related macular degeneration (AMD). Breakdown of the blood-retinal barrier (BRB) is linked to vision loss in DR and AMD. Our previous work revealed that HHcy altered BRB in retinal endothelial cells in vivo. Here we hypothesize that homocysteine (Hcy) alters retinal endothelial cell barrier function and angiogenic potential via activation of oxidative stress. Human retinal endothelial cells (HRECs) treated with and without different concentrations of Hcy showed a reduction of tight junction protein expression, increased FITC dextran leakage, decreased transcellular electrical resistance and increased angiogenic potential. In addition, HRECs treated with Hcy showed increased production of reactive oxygen species (ROS). The anti-oxidant N-acetyl-cysteine (NAC) reduced ROS formation and decreased FITC-dextran leakage in Hcy treated HRECs. A mouse model of HHcy, in which cystathionine-β-synthase is deficient (cbs−/−), was evaluated for oxidative stress by dichlolorofluorescein (DCF), dihydroethidium (DHE) staining. There was a marked increase in ROS production and augmented GSH reductase and antioxidant regulator NRF2 activity, but decreased antioxidant gene expression in retinas of hyperhomocysteinemic mice. Our results suggest activation of oxidative stress as a possible mechanism of HHcy induced retinal endothelial cell dysfunction.