Reduction In Glutathione Reductase Research Articles

Antibacterial, antibiofilm, and antivirulence effects of nanoparticles synthesized from Colletotrichum gloeosporioides in pathogenic E.coli

Antimicrobial resistance is a global problem and antibiotics are becoming ineffective due to the resistance developed by bacteria. In this current research, silver nanoparticles were synthesized from aqueous extract of endophytic fungi Colletotrichum gloeosporioides (CgAgNPs) and characterized by various methods. CgAgNPs efficacy was analyzed by performing antimicrobial assays in Escherichia coli ATCC 25922 and antibiotic resistant pathogenic strains. Upon treatment with CgAgNPs biofilm formation was reduced in all E.coli strains. In vitro cytotoxicity assays revealed that CgAgNPs were able to increase the membrane permeability and induced leakage of sugars and proteins. CgAgNPs induced oxidative stress in E. coli strains led to lipid peroxidation and release of malonaldehyde. The CgAgNPs were able to modulate the anti-oxidant system of cells hence there was a reduction in Glutathione reductase, Catalase and Superoxide dismutase enzymes activities. Analysis of expression of gene encoding CTX-M-15 showed the down regulation upon treatment with ampicillin and CgAgNPs. Overall, the results suggest that CgAgNPs control growth, biofilm formation in E. coli through induction of oxidative stress, interference with antioxidant enzymes, cell content leakage and finally downregulating the virulence gene by interfering with transcription and translation in E. coli. In future, CgAgNPs can be incorporated in formulations to break antibiotic resistance in antibiotic resistant pathogenic E. coli.

Effect of Plant Growth-Promoting Bacteria on Biometrical Parameters and Antioxidant Enzymatic Activities of Lupinus albus var. Orden Dorado Under Mercury Stress.

Heavy metal contamination of soils is a large-scale environmental problem. It leads to significant disqualification of the territory, in addition to being a source of the potential risk to human health. The exposure of plants to mercury (Hg) generates responses in its growth and their oxidative metabolism. The impact of increasing concentrations of Hg on the development of Lupinus albus var. Orden Dorado seedlings has been studied, as well as the plant’s response to the maximum concentration of Hg that allows its development (16 μg ml–1). The result shows that only the inoculum with plant growth promoting bacteria (PGPB) allows the biometric development of the seedling (root length, weight, and number of secondary roots) and prevents the toxic effects of the heavy metal from aborting the seedlings. Specifically, treatments with strains 11, 20 (Bacillus toyonensis), 48 (not determined), and 76 (Pseudomonas syringae) are interesting candidates for further PGPB-assisted phytoremediation trials as they promote root biomass development, through their PGPB activities. The plant antioxidant response has been analyzed by quantifying the catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR) enzyme activity in the root, under 16 μg ml–1 of HgCl2 and different PGPB treatments. Results show that, although Hg stress generally induces enzyme activity, strains 31 and 69I (Pseudomonas corrugata) and 18 and 43 (Bacillus toyonensis) can keep SOD and APX levels close to those found in control without Hg (p < 0.01). Strain 18 also shows a significant reduction of GR to control levels without Hg. The present work demonstrates the benefit of PGPB treatments in situations of high Hg stress. These findings may be a good starting point to justify the role of PGPB naturally isolated from bulk soil and the rhizosphere of plants subjected to high Hg pressure in plant tolerance to such abiotic stress conditions. More studies will be needed to discover the molecular mechanisms behind the phytoprotective role of the strains with the best results, to understand the complex plant-microorganism relationships and to find effective and lasting symbioses useful in bioremediation processes.

Thioredoxin system activation is associated with the progression of experimental pulmonary arterial hypertension

In addition to being an antioxidant, thioredoxin (Trx) is known to stimulate signaling pathways involved in cell proliferation and to inhibit apoptosis. The aim of this study was to explore the role of Trx in some of these pathways along the progression of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). Male rats were first divided into two groups: monocrotaline (MCT - 60 mg/kg i.p.) and control (received saline), that were further divided into three groups: 1, 2, and 3 weeks. Animals were submitted to echocardiographic analysis. Right and left ventricles were used for the measurement of hypertrophy, through morphometric and histological analysis. The lung was prepared for biochemical and molecular analysis. One week after MCT injection, there was an increase in thioredoxin reductase (TrxR) activity, a reduction in glutathione reductase (GR) activity, and an increase in Trx-1 and vitamin D3 up-regulated protein-1 (VDUP-1) expression. Two weeks after MCT injection, there was an increase in VDUP-1, Akt and cleaved caspase-3 activation, and a decrease in Trx-1 and Nrf2 expression. PAH-induced by MCT promoted a reduction in Nrf2 and Trx-1 expression as well as an increase in Akt and VDUP-1 expression after three weeks. The increase in pulmonary vascular resistance was accompanied by increased TrxR activity, suggesting an association between the Trx system and functional changes in the progression of PAH. It seems that Trx-1 activation was an adaptive response to MCT administration to cope with pulmonary remodeling and disease progression, suggesting a potential new target for PAH therapeutics.

Effect of thymoquinone on cyclophosphamide-induced injury in the rat urinary bladder

IntroductionCyclophosphamide (CP) is a chemotherapeutic agent used to treat neoplastic diseases, but its side effects include hemorrhagic cystitis. Thymoquinone (TQ) is an active ingredient of Nigella sativa with healing potential. This study examined the protective effect of TQ against CP-induced oxidative injury in rat urinary bladder.Material and methodsSixty rats were divided into 6 equal groups: untreated control (group A), TQ-treated with 10 mg/kg/day TQ for 10 days (group B1), TQ-treated with 100 mg/kg/day TQ for 5 days (group B2), toxicity control where 100 mg/kg CP was administered for 2 days (group C), CP + TQ-treated with the same TQ treatment as group B1 and 100 mg/kg CP for 2 days (group D1), and CP + TQ-treated with the same TQ treatment as group B2 and 100 mg/kg CP for 2 days (group D2). Rat urinary bladders were assessed histopathologically via hematoxylin and eosin (H&amp;E) and Masson’s trichrome stains and were evaluated for oxidative stress and cell death markers.ResultsCP demonstrated significant reduction in glutathione reductase, and increased malondialdehyde levels and protein carbonylation (both p &lt; 0.05). CP also induced cell death as measured by caspase-3 activation. Pretreatment with TQ (group D2) reduced CP-induced oxidative stress and apoptosis.ConclusionsTQ may ameliorate CP-induced oxidative injury in rat urinary bladder, via its antioxidant and antiapoptotic effects.

Evaluation of oxidative stress induced by cadmium and comparative antioxidant effects of Shirazi thyme (Zataria multiflora Boiss) and vitamin E in common carp (Cyprinus carpio)

Shirazi thyme is an active phytobiotc contains phenolic compounds and flavonoids which have strong antioxidant properties. This study was conducted to investigate the potential protective effects of Shirazi thyme compared to that of vitamin E against cadmium toxicity. Common carp juveniles (34±3 g) were divided into four groups and fed by three different diets including commercial diet without any additive (for control and metal only group) and supplemented with either 1% ground Shirazi thyme or 100 mg/kg vitamin E. All treatments except the control were exposed to sublethal concentration of waterborne cadmium (1.5 mg/L free ion) for 15 d and liver, kidney and gill were sampled 3, 7, 10 and 15 days after the metal exposure. Results showed that treatment of the fish with cadmium for 15 days resulted in a significant reduction in glutathione reductase (GR), glutathione-S-transferase (GST) and catalase (CAT) and led to liver, kidney and gills dysfunction. On the other hand, the level of malondialdehyde (MDA) significantly increased during metal exposure. Supplementation of diets with Shirazi thyme and vitamin E led to a significant protection against metal exposure in different tissues. Moreover, Shirazi thyme was found to be as effective as vitamin E. The current finding can provide a useful reference for stress protective effects of thyme and its beneficial role in aquaculture.

Morphofunctional characteristics of the glutathione cycle in peripheral blood erythrocytes of pregnant women with a history of cytomegalovirus infection exacerbation during gestation.

We studied factors influencing peripheral blood erythrocytes of pregnant women with exacerbation of cytomegalovirus infection during gestation. Cytomegalovirus infection was associated with a decrease in the content of reduced glutathione in erythrocytes and glutathione peroxidase, which leads to H2O2 accumulation in the blood. Exacerbation of cytomegalovirus infection was associated with reduction of glutathione reductase and SOD activities. Erythrocyte antioxidant function and the peripheral blood discocyte count decreased. Accumulation of degenerative erythrocytes is fraught with the risk of anemia in pregnant women.

Physiological plasticity of Dictyota kunthii (Phaeophyceae) to copper excess

The brown alga Dictyota kunthii is one of the dominant species in the coastal areas of northern Chile affected by copper enrichment due to accumulated mining wastes. To assess its physiological plasticity in handling copper-mediated oxidative stress, 4-days copper exposure (ca. 100μg/L) experiments were conducted with individuals from a copper impacted area and compared with the responses of plants from a non-impacted site. Several biochemical parameters were then evaluated and compared between populations. Results showed that individuals from the copper-impacted population normally displayed higher levels of copper content and antioxidant enzymes activity (catalase (CAT), ascorbate peroxidase (AP), dehydroascorbate reductase (DHAR), glutathione peroxidase (GP) and peroxiredoxins (PRX)). After copper exposure, antioxidant enzyme activity increased significantly in plants from the two selected sites. In addition, we found that copper-mediated oxidative stress was associated with a reduction of glutathione reductase (GR) activity. Moreover, metabolic profiling of extracellular metabolites from both populations showed a significant change after plants were exposed to copper excess in comparison with controls, strongly suggesting a copper-induced release of metabolites. The copper-binding capacity of those exudates was determined by anodic stripping voltammetry (ASV) and revealed an increased ligand capacity of the medium with plants exposed to copper excess. Results indicated that D. kunthii, regardless their origin, counteracts copper excess by various mechanisms, including metal accumulation, activation of CAT, AP, DHAR, GP and PRX, and an induced release of Cu binding compounds. Thus, plasticity in copper tolerance in D. kunthii seems constitutive, and the occurrence of a copper-tolerant ecotype seems unlikely.

Insecticides and Bio-insecticides Modulate the Glutathione-related Antioxidant Defense System of Cowpea Storage Bruchid (Callosobruchus maculatus).

The possible cellular involvements of cowpea storage bruchid (Callosobruchus maculatus (Fab.) [Coleoptera: Chrysomelidae]) glutathione and its related enzymes system in the cellular defense against insecticides (Cypermethrin and λ-cyhalothrin) and bio-insecticides (ethanolic extract of Tithonia diversifolia, Cyperus rotundus, Hyptis suavolens leaves, and Jatropha curcas seed) were investigated. The results showed that the effect of insecticides and bio-insecticides on the C. maculatus is a function of oxidative and nitrosative stresses generated in vivo. A significant (p < 0.05) increase in carbonyl protein (CP) and lipid peroxidation (LPO) contents in bio-insecticides and insecticides exposed groups compared to the control indicates the extent of vital organs damage. These stresses caused similar and significant increase of glutathione peroxidase and glutathione synthetase in response to insecticides and bio-insecticide exposure in a dose-dependent manner. There was no post-translational modification of glutathione transferases expression induced. The alterations of the insect glutathione-dependent antioxidant enzyme activities reflect the presence of a functional defense mechanism against the oxidative and nitrosative stress and are related firmly to the glutathione demands and metabolism but appear inadequate by the significant reduction in glutathione reductase (GR) activity to prevent the damages. Exogenous application of reduced glutathione (GSH), to complement the in vivo demand, could not protect against the onslaught.

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

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

Oxidative Stress Peripheral Biomarkers in Mild Cognitive Impairment and Alzheimer's Disease

It is well established that oxidative stress is associated with aging and neurodegenerative processes, such as Alzheimer's disease (AD). Our aim was to determine plasma malondialdehyde (MDA), a lipid peroxidation marker, and to measure the activity of five erythrocytary antioxidant enzymes: catalase, superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and gluthatione S-transferase (GST) on healthy aged subjects and in individuals with mild cognitive impairment (MCI) and AD. MCI is usually seen as an intermediate condition between healthy aging and AD. Twenty eight healthy subjects (60-81 years), 35 patients with MCI (61-87 years) and 32 with AD (68-90 years) were included in this study. Blood (20 mL) was collected in heparin tubes and centrifuged at 700-1000g (10 min/4°C). Plasma was separated and stored at -80°C. Erythrocytes were washed three times with saline solution and stored at -80°C. Enzymatic colorimetric methods were used to evaluate enzymatic activities. MDA levels were measured by HPLC by UV/Vis detection. No differences in SOD and GST activities were detected among AD, MCI and healthy controls. MDA levels, as well catalase and GPx activities, were similar in MCI and healthy individuals and higher in AD. Finally, GR activity was lower in MCI and AD patients than in healthy aged subjects. Additionally, healthy controls have a significantly higher GR/GPx ratio, when compared with MCI; the same occurred when the group of MCI individuals was compared with the AD patients. Reduction of GR seems to be a hallmark of cognitive decline, but GR/GPx ratio was more strongly associated with progression of cognitive decline, being higher in healthy subjects, intermediate in MCI and lower in AD subjects. A reduced capacity to restore glutathione (GSH) levels might be the main source of increased oxidative stress status in cognitive decline. Supported by FAPESP

Effects of BDE-99 on hormone homeostasis and biochemical parameters in adult male rats

In this study, we evaluated the effects of BDE-99 on hormone homeostasis, as well as in urinary and serum biochemical parameters of adult male rats. Animals (10 per group) received BDE-99 by gavage at single doses of 0, 0.6 and 1.2 mg/kg. Forty-five days after BDE-99 exposure, urine and serum samples were collected for hormonal and biochemical analysis. Oxidative stress (OS) markers in erythrocytes, plasma and urine were also evaluated. Urinary excretion of total protein significantly increased following BDE-99 exposure, while lactate dehydrogenase (LDH), γ-glutamil transferase (GGT), and N-acetylglucosaminidase (NAG) activities significantly decreased. Liver toxicity was evidenced by elevated serum activities of the enzymes glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT) and alkaline phosphatase (ALP). Following BDE-99 administration, OS markers in erythrocytes showed an increase in superoxide dismutase (SOD) activity, and a reduction in glutathione reductase (GR) activity. In urine, isoprostane levels increased after BDE-99 exposure. The hormonal analysis showed a significant decrease in testosterone and progesterone levels. These results support the hypothesis that BDE-99 interacts with hormonal response. Moreover, BDE-99 administration to adult male rats showed signs of renal and hepatic toxicity.

Biochemical alterations in juvenile carp (Cyprinus carpio) exposed to zinc: Glutathione reductase as a target

The aim of this study was to investigate biochemical changes in juvenile carp (Cyprinus carpio) exposed to zinc chloride (10, 30 and 100 microM) for a period of 48 h. Zinc exposure caused a concentration-dependent reduction in glutathione reductase (GR) activity in gills, liver and brain. Gill glutathione S-transferase (GST) was reduced when animals were exposed to the highest concentration of 100 microM zinc. The phosphorylation of p38(MAPK) increased in the brain of fish exposed to zinc 100 microM, while phosphorylation of the extracellular signal-regulated protein kinase 1/2 (ERK1/2) and c-Jun N-terminal protein kinase 1/2 (JNK1/2) remained unchanged. Expression of proteins HSP60 and HSP70 were not affected by zinc exposure. Considering the significant concentration-dependent inhibition of GR in all tissues analyzed, this enzyme could be a potential biomarker of exposure to zinc, which has to be confirmed.

Antioxidant defenses and lipid peroxidation in the cerebral cortex and hippocampus following acute exposure to malathion and/or zinc chloride

This study investigates the effects of acute exposure to organophosphate insecticide malathion (250 mg/kg, i.p.) and/or ZnCl2 (5 mg/kg, i.p.), with the following parameters: lipid peroxidation and the activity of acetylcholinesterase (AChE), glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPx), glucose-6-phosphate dehydrogenase (G6PDH), and the levels of total glutathione (GSH-t) in the hippocampus and cerebral cortex of female rats. Malathion exposure elicited lipid peroxidation and reduced AChE activity in the cerebral cortex and hippocampus. It also reduced the activity of GR and GST, and increased G6PDH activity in the cerebral cortex, without changing the levels of GSH-t and GPx activity. ZnCl2 exposure reduced AChE activity and caused a mild pro-oxidative effect, since lipid peroxidation was increased in the hippocampus. ZnCl2, individually or in combination with malathion, caused a reduction in GR and GST activity in the cerebral cortex. Malathion and/or ZnCl2 did not change the GSH-t levels. Moreover, ZnCl2 prevented the increase in G6PDH activity caused by malathion. It showed that ZnCl2 had little effect against the changes induced by malathion. In fact, zinc itself produced pro-oxidant action, such as the reduction in the activity of the antioxidant enzymes GR and GST.

Drought and air pollution affect nitrogen cycling and free radical scavenging inPinus halepensis(Mill.)

Fumigation of Aleppo pines with episodes of O3 (up to 110 nl l–) causes immediate depressions of in vivo nitrate reductase (NaR) activities, slightly delayed reductions in the rates of ethene emissions (typical of O3 plants), steady accumulations of total polyamines (although putrescine declines), and increases in pool sizes of reduced glutathione (GSH) and ascorbate in current year needles. Severe droughting produces smaller plants with reduced stomatal conductance and CO2 assimilation rates as well as lower protein contents. Their roots have low rates of nitrate uptake but virtually no root NaR activities, while levels of shoot activities and NaR-associated proteins are unaffected although they have no substrate. Less severe droughting allows a restricted uptake of nitrate which is still reflected in reduced NaR activities, protein and total N contents, but the additional presence of O3 (up to 120 nl l–1) has no interactive effect on N cycling. Drought and O3 together, however, depress CO2 assimilation still further, which can not be accounted for by additional stomatal closure, but the interactive effects of drought and air pollution reduce levels of total phenols, GSH and ascorbate which, combined with a 12-fold reduction in glutathione reductase-(GR)-associated proteins, point to an increased susceptibility of Aleppo pines to photoinhibition as a reason for their current decline in Mediterranean areas.