Increase In Glutathione Reductase Activity Research Articles

Effect of CO2 exposure on the antioxidant enzymes activity and gill histology of adult zebrafish (Danio rerio)

Increase in carbon dioxide level is considered as a threat to all living organisms and in particular aquatic organisms are vulnerable. Although a number of studies were carried out to predict the effect of increased CO2 with marine organisms, fresh water fish were the least concerned ones. Therefore, the aim of this study was to study the effect of antioxidant enzymes in zebrafish exposed to acute concentration of CO2 (based on prediction for 2300). Three ranges of pH were selected below the range where no fatality was observed, 6.0 – 6.5, 5.5 – 6.0 and 5.0 – 5.5. Antioxidant enzyme analysis of superoxide dismutase (SOD), catalase (CAT), lipid peroxidation (LP), glutathione reductase (GR) and glutathione peroxidase (GPx) was performed for the tissues, liver, gills and muscles. Although a significant decrease in SOD activity was observed in all three tissues, only a slight variation in CAT activity was found in all the tissues. MDA content which is an indicator of lipid peroxidation showed an increasing pattern in all the tissues. A slight increase in GR activity was found in all the tissues; however, a significant decrease in GPx activity was noted. Further, the histology of gills exposed to CO2 showed marked damage and injury including lamellar fusion and necrosis. Our study concludes that exposure to CO2 has led to oxidative stress which has resulted in cellular injury and damage

Ecophysiological responses of two closely related epigean and hypogean Niphargus species to hypoxia and increased temperature: Do they differ?

Ecological performance of animals depends on physiological and biochemical processes that are adjusted to the environment. The responses to hypoxia or anoxia have been frequently studied in subterranean aquatic organisms in order to find potential adaptations to restrict oxygen conditions occurring in the underground habitats. However, some previous studies have compared phylogenetic distant epigean and hypogean species or the epigean and hypogean populations of the same species due to little chance to compare closely related epigean and hypogean species. Therefore, in this study, we compared the effects of exposure to hypoxia, followed by reoxygenation, and increased temperature on oxygen consumption, potential metabolic activity, and antioxidant activities in closely related epigean and hypogean species: Niphargus zagrebensis and N. stygius. Oxygen consumption of N. stygius increased similarly during post-hypoxic recovery at 10 and 20°C (approx. 5-times), while N. zagrebensis increased its oxygen consumption for 9.7 and 4.4-times at 10 and 20°C, respectively. We observed higher exploitation of metabolic potential for current oxygen consumption during reoxygenation in N. zagrebensis than N. stygius. Exposure to hypoxia and subsequent reoxygenation at 20°C increased catalase (CAT) activity in N. stygius, but not in N. zagrebensis. We observed increased glutathione reductase activity in both Niphargus species. We concluded that respiratory and antioxidant responses to severe hypoxia and increased temperature differed between closely related epigean and hypogean Niphargus species. Hypogean Niphargus species possess physiological and biochemical characteristics that are advantageous in temperature stable subterranean environments which support inhabiting of species that have low energetic demands, while epigean Niphargus species can successfully inhabit specific surface habitats.

Resveratrol Improves Hepatic Redox Status and Lipid Balance of Neonates with Intrauterine Growth Retardation in a Piglet Model.

Abnormal lipid metabolism, oxidative stress (OS), and inflammation play a pivotal role in the increased susceptibility to neonatal fatty liver diseases associated with intrauterine growth retardation (IUGR). This study was firstly conducted to investigate whether resveratrol could alleviate IUGR-induced hepatic lipid accumulation, alteration of redox and immune status in a sucking piglet model and explore the possible mechanisms at transcriptional levels. A total of 36 pairs of 7 d old male normal birth weight (NBW) and IUGR piglets were orally fed with either 80 mg resveratrol/kg body weight/d or 0.5% carboxymethylcellulose sodium for a period of 14 days, respectively. Compared with the NBW piglets, the IUGR piglets displayed compromised growth performance and liver weight, reduced plasma free fatty acid (FFA) level, increased hepatic OS, abnormal hepatic lipid accumulation and weakened hepatic immune function, and hepatic aberrant transcriptional expression of some genes such as heme oxygenase 1, superoxide dismutase 1, sterol regulatory element-binding protein 1c, stearoyl-CoA desaturase 1, liver fatty acid-binding proteins 1, toll-like receptor 4, and tumor necrosis factor alpha (TNF-α). Oral administration of resveratrol to piglets decreased the levels of FFA and total triglycerides (TG) in the plasma and hepatic TNF-α concentration, and increased glutathione reductase activity and reduced glutathione level in the liver. Resveratrol restored the increased alanine aminotransferase activity in the plasma of IUGR piglets. Treatment with resveratrol ameliorated the increased hepatic malondialdehyde, protein carbonyl, TG, and FFA concentrations induced by IUGR. Resveratrol treatment alleviated the reduced lipoprotein lipase activity and its mRNA expression as well as TNF-α gene expression in the liver of IUGR piglets. Hepatic glutathione peroxidase 1 and monocyte chemotactic protein 1 genes expression of piglets was upregulated by oral resveratrol administration. In conclusion, resveratrol administration plays a beneficial role in hepatic redox status and lipid balance of the IUGR piglets.

Effects of Long-Term Supplementation with Aluminum or Selenium on the Activities of Antioxidant Enzymes in Mouse Brain and Liver

The aim of this study was to investigate the effects of aluminum (Al) or selenium (Se) on the “primary” antioxidant defense system enzymes (superoxide dismutase, catalase, and glutathione reductase) in cells of mouse brain and liver after long-term (8-week) exposure to drinking water supplemented with AlCl3 (50 mg or 100 mg Al/L in drinking water) or Na2SeO3 (0.2 mg or 0.4 mg Se/L in drinking water). Results have shown that a high dose of Se increased the activities of superoxide dismutase and catalase in mouse brain and liver. Exposure to a low dose of Se resulted in an increase in catalase activity in mouse brain, but did not show any statistically significant changes in superoxide dismutase activity in both organs. Meanwhile, the administration of both doses of Al caused no changes in activities of these enzymes in mouse brain and liver. The greatest sensitivity to the effect of Al or Se was exhibited by glutathione reductase. Exposure to both doses of Al or Se resulted in statistically significant increase in glutathione reductase activity in both brain and liver. It was concluded that 8-week exposure to Se caused a statistically significant increase in superoxide dismutase, catalase and glutathione reductase activities in mouse brain and/or liver, however, these changes were dependent on the used dose. The exposure to both Al doses caused a statistically significant increase only in glutathione reductase activity of both organs.

Effects of chronic exposure of waterborne copper on the antioxidant system and tissue accumulation in golden trout (Oncorhynchus mykiss aguabonita).

We assessed the acute and chronic effects of copper (Cu2+) on the antioxidant system in golden trout (Oncorhynchus mykiss aguabonita). The median lethal concentration after 96h was determined as 0.24mgL-1. We then used 0.06 (L) and 0.12mgL-1 (H) Cu2+ to assess the responses of the antioxidant system to long-term exposure. The activities of superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase, glutathione reductase, reduced glutathione, and oxidized glutathione were measured in gill and liver tissue after 24 and 72h and 7, 14, 21, and 28days of exposure, as well as after 16days of recovery in Cu2+-free water. Cu2+ accumulated to a greater extent in the liver than in the gill (0.61-0.75mgkg-1 vs. 24.0-69.9mgkg-1 in L group and 0.98-1.47mgkg-1 vs. 33.3-66.03mgkg-1 in H group). In the gill, we observed increases in the activities of superoxide dismutase, catalase, and glutathione peroxidase, as well as in the concentrations of reduced glutathione and oxidized glutathione. In the liver of L group, we observed increases in glutathione reductase activity and in the levels of reduced glutathione and oxidized glutathione. In L group, the activity of superoxide dismutase and reduced glutathione content increased after 24h and then decreased over time, while catalase and glutathione reductase activity and oxidized glutathione levels increased. Data from the recovery period indicated that higher concentrations of Cu2+ may induce irreversible oxidative damage to the gill of golden trout.

Influence of Dietary Astaxanthin on the Hepatic Oxidative Stress Response Caused by Episodic Hyperoxia in Rainbow Trout.

A 13-week feeding trial was carried out with juvenile rainbow trout to test two diets: a control diet without astaxanthin (AX) supplementation (CTRL diet), and a diet supplemented with 100 mg/kg of synthetic AX (ASTA diet). During the last week of the feeding trial, fish were exposed to episodic hyperoxia challenge for 8 consecutive hours per day. Episodic hyperoxia induced physiological stress responses characterized by a significant increase in plasma cortisol and hepatic glycogen and a decrease in plasma glucose levels. The decrease of plasma glucose and the increase of hepatic glycogen content due to episodic hyperoxia were emphasized with the ASTA diet. Hyperoxia led to an increase in thiobarbituric acid-reactive substances in the muscle, diminished by dietary AX supplementation in both liver and muscle. Muscle and liver AX were increased and decreased respectively after 7-day episodic hyperoxia, leading to an increase in flesh redness. This augment of muscle AX could not be attributed to AX mobilization, since plasma AX was not affected by hyperoxia. Moreover, hyperoxia decreased most of antioxidant enzyme activities in liver, whereas dietary AX supplementation specifically increased glutathione reductase activity. A higher mRNA level of hepatic glutathione reductase, thioredoxin reductase, and glutamate-cysteine ligase in trout fed the ASTA diet suggests the role of AX in glutathione and thioredoxin recycling and in de novo glutathione synthesis. Indeed, dietary AX supplementation improved the ratio between reduced and oxidized glutathione (GSH/GSSG) in liver. In addition, the ASTA diet up-regulated glucokinase and glucose-6-phosphate dehydrogenase mRNA level in the liver, signaling that dietary AX supplementation may also stimulate the oxidative phase of the pentose phosphate pathway that produces NADPH, which provides reducing power that counteracts oxidative stress. The present results provide a broader understanding of the mechanisms by which dietary AX is involved in the reduction of oxidative status.

EVALUATION OF GLUTATHIONE REDUCTASE (GR) ACTIVITY IN LIVER OF FISH, CHANNA PUNCTATUS (BLOCH, 1793) EXPOSED TO HEXAVALENT CHROMIUM

Antioxidant defence system is known to be a sensitive biomarker of metal exposure widely employed in predicting toxicity after sub-lethal exposure of Cr6+in fish. The present study conducted to assess the impact of Cr6+on Glutathione reductase (GR) activity in liver of fish, Channa punctatus. Fish were exposed to two different sub-lethal concentrations of Cr6+viz.,3.93 mg/L (5% of 96h LC50) (T1) and 7.85 mg/L (10% of 96h LC50) (T2) along with one control group without any toxicant exposure, for 15, 30 and 45 d. Results showa significant (p <0.05) increase in GR activity with an increase in dose and exposure period. This study emphasized the role of GR in monitoring of metal toxicity in aquatic regimes as an early warning tool.

Prior exercise protects against oxidative stress and motor deficit in a rat model of Parkinson's disease.

This study investigated if a prior long-term physical exercise protocol protects the substantia nigra and the striatum against oxidative stress and motor deficits in a Parkinson Disease model induced by 6-hydroxydopamine. Three animal treatment groups were included in the study: sham; 6-hydroxydopamine and 6-hydroxydopamine/exercise. Previously to the intrastriatal lesion by 6-hydroxydopamine, rats in the exercise groups performed a swimming program for 18weeks. The rats were submitted to behavioral tests before and after intrastriatal 6-hydroxydopamine injection. The oxidative stress was analyzed by Thiobarbituric Acid Reactive Substances and Glutathione reductase activity methods. The exercise decreased lipid peroxidation and increased glutathione reductase activity in the substantia nigra. In contrast, in the striatum, exercise increased lipid peroxidation and decreased glutathione reductase activity. Exercise increased contralateral rotations and reduces immobility levels at 14days post lesion. The exercise prior to 6-OHDA lesion had protective action only in substantia nigra against oxidative stress.

Dietary fiber and fiber-bound polyphenols of grape peel powder promote GSH recycling and prevent apoptosis in the colon of rats with TNBS-induced colitis

Abstract Ulcerative colitis (UC) is a chronic inflammatory bowel disease that reduces glutathione (GSH) levels. We aimed to investigate the effect of dietary supplementation with grape peel powder (GPP) on the GSH system in a rat model of colitis induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) and to identify the role of grape bioactive fractions, namely soluble phenolics (EP), fiber-bound polyphenols (NEP-F), and dietary fiber (F). Colitis reduced colonic GSH levels and glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST) activities. NEP-F completely restored GR and GPx, while all diets restored GST activities. Colitis increased the mRNA expression of both subunits of glutamate-cysteine ligase and induced apoptosis in the colon. The reestablishment of GSH levels promoted by GPP was associated with the recycling of oxidized glutathione by increased GR activity instead of GSH synthesis. NEP-F and F fractions were responsible for the protective effect of GPP against apoptosis.

The influence of apocynin, lipoic acid and probiotics on antioxidant enzyme levels in the pulmonary tissues of obese asthmatic mice

Bronchial asthma and obesity are common health problems. Obesity is already responsible for 300,000 deaths per year. AimsThe aim of the present study was to assess whether apocynin, alpha lipoic acid and probiotic administration in combination with low-fat diet supplementation influences the levels of antioxidant enzymes in the pulmonary tissues of obese asthmatic mice. Main methodsThe study was performed on male C57/BL6 mice divided into 10 groups: (I) control; (II) asthma; (III) obesity; (IV) asthma + obesity; (V) asthma + obesity + apocynin p.o. 15 mg/kg/day for 12 weeks; (VI) asthma + obesity + low-fat diet for 12 weeks; (VII) asthma + obesity + low-fat diet for 12 weeks with apocynin p.o. 15 mg/kg/day; (VIII) asthma + obesity + low-fat diet with probiotics for 12 weeks; (IX) asthma + obesity + low-fat diet for 12 weeks with lipoic acid p.o. 100 mg/kg/day for 12 weeks; (X) asthma + obesity + standard diet with probiotics for 12 weeks. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) activity were examined. The administration of apocynin alone and apocynin in combination with a low-fat diet resulted in a significant increase in SOD values (respectively p < 0.001; p = 0.010). Application of probiotics resulted in a decrease in CAT activity (p = 0.037) and an increase in GPx activity (p < 0.001) compared to obese asthmatic mice. The administration of lipoic acid resulted in an increase in GR activity (p = 0.024 vs. control). Key findingsSupplementation containing apocynin, lipoic acid and probiotics has a positive influence on the antioxidant capacity of the pulmonary tissues of obese asthmatic mice. SignificanceThese results may contribute to the development of new therapeutic approaches.

LcSABP2, a salicylic acid binding protein 2 gene from Lycium chinense, confers resistance to triclosan stress in Nicotiana tabacum

The triclosan (TCS) is one of the most commonly detected organic pollutants in the sewage sludge. TCS could induce phytotoxicity in plants. Salicylic acid (SA) is a phenolic compound capable of enhancing plant growth and development. It is well documented that abiotic stress tolerance could be enhanced by exogenous application of SA. However, the regulatory mechanisms for functions of endogenous SA in plants' responses to xenobiotics stress remains unclear. Our results indicated that TCS suppressed plant growth by restricting photosynthesis, decreasing chlorophyll contents and inducing over production of reactive oxygen species (ROS). Interestingly, SA or glutathione (GSH) application could significantly improve plant tolerance to TCS. Moreover, endogenous SA and the expression of a SA binding protein 2 (SABP2) gene were found to be elevated in tobacco under TCS treatment. The overexpression of LcSABP, a SABP2-like gene cloned from the leaves of Lycium chinense, markedly enhanced the SA content in the transgenic plants under TCS stress. The LcSABP-overexpressing plants presented higher photosynthesis rate, chlorophyll content, glutathione reductase (GR) and glutathione-S-transferase (GST) enzymes activities, GSH content and lower O2−•, H2O2 and malondialdehyde (MDA) content in comparison with WT tobacco with TCS treatment. One of the GSH synthesis-related gene, NtGSHS, also showed higher expression level in the transgenic tobacco in comparison with control plants with TCS stress treatment. These results indicated that SABP2 played a positive regulatory role in plant response to TCS stress via increasing the endogenous SA levels. The increased SA content might then increase the GSH content, probably through an increase in GR activity and GSHS gene expression, thus inducing the antioxidant and xenobiotics detoxification systems, which promoted TCS stress tolerance in tobacco plants.

Effect of protein hydrolysates from carp (Cyprinus carpio) skin gelatine on oxidative stress biomarkers and other blood parameters in healthy rats

Abstract Carp skin gelatine hydrolysates can be a potential source of bioactive peptides with strong antioxidant properties tested in vitro, but there is no information on in vivo activity. Therefore, the objective of this study was to determine the ability of an antioxidant carp skin gelatine hydrolysate to attenuate plasma/serum levels of some oxidative stress markers in healthy adult Wistar rats. Analysis of hydrolysate included safety in an animal organism (haematological blood parameters, CRP, hepatic and kidney function), biological value (BV, TD, NPU), evaluation of the lipid profile (TC, LDL-C, HDL-C, TAG) and antioxidant blood status (TAS, MDA, GSR, HO-1). The results indicate that fish protein hydrolysates are safe for laboratory animals, but have very low biological value. An increase in glutathione reductase activity in the blood serum of healthy animals fed with carp skin gelatine hydrolysate supplements is a promising indicator of its antioxidant in vivo properties.

Oxidative stress in electrohypersensitivity self‑reporting patients: Results of a prospective invivo investigation with comprehensive molecular analysis.

A total of 32 electrohypersensitivity (EHS) self-reporting patients were serially included in the present prospective study for oxidative stress and antioxidative stress response assessment. All thiobarbituric acid-reactive substances (TBARs) were measured in the plasma, particularly malondialdehyde (MDA) for lipid peroxidation; additional measurements included total thiol group molecules, reduced glutathione (GSH), oxidized glutathione (GSSG) for oxidative stress assessment and nitrotyrosine, a marker of peroxynitrite-induced oxidative/nitrosative stress. In addition, the activity of Cu-Zn superoxide dismutase (SOD1) was measured in red blood cells (RBCs) and glutathione reductase (GR) and glutathione peroxidase (GPx) in RBCs and plasma. Depending of the biomarker considered, 30–50% of EHS self-reporting patients presented statistically significantly increased TBARs, MDA, GSSG and NTT mean plasmatic level values in comparison with normal values obtained in healthy controls (P<0.0001). By contrast, there were no plasmatic level values above the upper normal limits for GSH, GSH/GSSG ratio, total glutathione (GluT) and GSH/GluT ratio, and values for these GSH-associated biomarkers were statistically significantly decreased in 20–40% of the patients (P<0.0001). Furthermore, in RBCs, mean SOD1 and GPx activities were observed to be statistically significantly increased in ~60% and 19% (P<0.0001) of the patients, respectively, while increased GR activity in RBCs was observed in only 6% of the patients. The present study reports for the first time, to the best of our knowledge, that overall ~80% of EHS self-reporting patients present with one, two or three detectable oxidative stress biomarkers in their peripheral blood, meaning that these patients-as is the case for cancer, Alzheimer's disease or other pathological conditions-present with a true objective new pathological disorder.

ОСОБЛИВОСТІ РЕАКЦІЇ ГЛУТАТІОНОВОЇ СИСТЕМИ ВНУТРІШНІХ ОРГАНІВ НА ТЛІ ЕКСПЕРИМЕНТАЛЬНОЇ ПОЛІТРАВМИ

Nowadays stop the bleeding and fight against its consequences determines further success in the survival and rehabilitation of the victim. It is extremely important to find ways to improve the ischemic metabolism as a result of overlaying a tissue turnstile. Enzymes of the glutathione system are actively involved in combating the effects of hypoxia, therefore, the experimental detection of critical periods of depression of this protectional link is the basis for the further search for effective methods of correction and condition stabilization of the affected organism.The aim of the study – to determine the role of glutathione system of the liver and kidneys in the pathogenesis of experimental ischemia-reperfusion (EIR) in the early and remote post-traumatic periods.Materials and Methods. The object of the study – 196 males of white male rats with a body weight 220–240 g, divided into 4 groups, 10 individuals in each. Animals of the control group were withdrawn from the study without surgical intervention, while in the experimental groups, injuries were simulated: a hemostatic tourniquet on the thigh (J) over two hours; isolated blood loss from the femoral vein (40%) – (K); two-hour ischemia, combined with blood loss (J + K) and two-hour ischemia, combined with blood loss and mechanical trauma (J + K + P). The animals were withdrawn from the experiment at 1, 3, 7 and 14 days after the intervention by total bleeding from the heart.Results and Discussion. According to the activation of the lipid peroxidation, which was represented by the growth of the concentration of malonic dialdehyde, diene and trienic conjugates, an active response from the glutathione system was detected: the activation of glutathioneperoxidase activity, an increase of glutathionereductase activity against the decrease restored glutathione concentration. But in the kidney tissue the activity of glutathione system enzymes was somewhat lower, herewith in some periods, conversly, they exceeded liver parameters. These results, in our opinion, indicate that the reason of such their dividing, mainly, it is total debilitation of the glutathione system in the posttraumatical period. It was 1 and 3 days after trauma and partly depended of the injury severity. At the same time, even an isolated overlay of the hemostatic tourniquet led to significant changes of the glutathione system and was represented by response to the activation of lipid peroxidation. This confirms the necessity to continue the series of experiments.Conclusions. The obtained results of the experiments revealed a significant inhibition of the reduced glutathione concentration in the liver, and no so expressed in the kidneys. Especially depression of its activity was on the background of bleeding associated with ischemia, and bleeding associated with ischemia and mechanical trauma. Decrease of glutathioneperoxidase and glutathionereductase activity coincided with increase of lipid peroxidation.

Silicon promotes growth and root yield of Glycyrrhiza uralensis under salt and drought stresses through enhancing osmotic adjustment and regulating antioxidant metabolism

Silicon promotes beneficial effects that improve plant tolerance to salt and drought stresses though the mechanisms that cause these effects remain poorly understood. Glycyrrhiza uralensis Fisch. ex DC. (G. uralensis) is an important Chinese herb plant of the family Leguminosa. In this study, pot experiments were conducted to investigate the long-term effects of silicon on growth and physio-biochemical characteristics of two-year-old G. uralensis subjected to salt and drought stresses. The results showed that all stress treatments decreased G. uralensis growth and this adverse effect was reversed by addition of silicon. Added silicon also affected physio-biochemical characteristics of G. uralensis, and these effects varied depending on levels of salt and drought stresses and the developmental stages of the studied plants. Silicon reduced Na+ content and correspondingly increased K+/Na+ ratio. Silicon also increased soluble sugar and proline contents under salt combined drought stress respectively at 110 days and increased soluble protein content under all stress treatments at 70 days. Silicon increased catalase and ascorbate peroxidase activities under all stress treatments. Silicon also increased glutathione reductase activity, which was accompanied by increasing glutathione content under salt combined drought stress. These changes caused decrease of reactive oxygen species, malondialdehyde content and membrane permeability correspondingly. In sum, silicon benefited alleviation of osmotic and oxidative stresses induced by salt and drought stresses on G. uralensis mediated by regulating osmolytes to improve water status and antioxidants to maintain membrane stability.

The oxygen concentration in cultures modulates protein expression and enzymatic antioxidant responses in Metarhizium lepidiotae conidia

Conidia from Metarhizium spp. are used for integrated pest control; however, environmental factors diminish the effectivity of these programs. Several approaches tried to improve conidia resistance to overcome this limitation, although little is known about the mechanisms involved in this effect. Here we measured the activity of antioxidant enzymes and conidia virulence, comparing the proteomic profiles of Metarhiziumlepidiotae CP-OAX conidia produced under normal (21% O2) and high oxygen atmospheres (pulses with 30% O2). We detected a higher virulence against Tenebrio molitor larvae, in addition to an increase in ultraviolet light tolerance in conidia produced under 30% O2, which correlates with increased glutathione reductase activity. Two-dimensional gel electrophoresis (2D SDS–PAGE) of proteins extracted in conidia harvested from both experimental conditions revealed a group of proteins that was observed only in conidia from oxidant atmospheres. Some of those proteins were directly involved in oxidative stress responses, whereas others were involved in conidial virulence, thermo-tolerance, and the central metabolism. Thus, a high atmospheric oxygen concentration (30%) activates antioxidant defence and general stress response mechanisms involved in conidia resistance to adverse environmental factors, which can ultimately translate into higher effectivity for the use of entomopathogenic fungi conidia in pest control.

Multi-omics analyses of red blood cell reveal antioxidation mechanisms associated with hemolytic toxicity of gossypol.

Gossypol is an antiproliferative drug with limited use due to its hemolytic toxicity. In this study, accelerated hemolysis was observed in the cows treated with gossypol. Comparative metabolomics were used to gain responsive pathways in the red blood cell (RBC) to the treatment, which were crossly validated by parallel iTRAQ-based proteomic analysis and enzyme activity assay. We found that gossypol treatment appeared to considerably activate pentose phosphate pathway (PPP) with an increased key product of ribose-5-phosphate and the increased abundance and activity of several key enzymes such as 6-phosphogluconate dehydrogenase, flavin reductase, and ribose-phosphate pyrophesphokinase. Meanwhile, a decreased glycolysis metabolism was observed, as many input metabolites of glycolysis were reduced in the gossypol group, whereas its distal metabolites were unchanged, along with decreased abundance of triosephosphate isomerase and increased abundance of enzymes catalyzing several distal glycolytic steps. Oxidative reduction pathways were also remarkably affected as we found a decreased substrate of flavin reductase, glutathione disulfide, increased glutathione reductase activity, and increased abundance and activity of glutathione S-transferase with the increase of its catalytic product, cysteine. Our results demonstrated that glycolysis, PPP, and oxidative reduction pathways of RBC were all involved in RBC’s response to the hemolytic toxicity of gossypol.

The evaluation of the changes in enzymatic antioxidant reserves and lipid peroxidation in chosen parts of the brain in an animal model of Parkinson disease.

Parkinson's disease is a progressive neurodegenerative disorder, characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta. The causes of Parkinson's disease are not fully understood; however, increasing evidence implicates oxidative stress. The study was aimed at assessing the nature of the changes in the oxidation-antioxidant balance in the cerebral cortex, striatum, hippocampus, thalamus, and cerebellum in a rat model of Parkinson's disease (PD). Sixteen male Wistar rats were divided into 2 groups: Icontrol, IIParkinson's disease. The 8-weeks-old animals were decapitated, their brains removed and the following structures dissected and then frozen for further biochemical assays: cerebral cortex, striatum, hippocampus, thalamus and cerebellum. The activities of: the catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione S-transferase (GST), superoxide dismutase (SOD) and the isoenzymes: Cu/ZnSOD and MnSOD; together with the malondialdehyde (MDA) and the total oxidative status (TOS) concentrations were measured in each structure. A significantly increased activities of SOD, Cu/ZnSOD, GST and reduced GR activity and an increase of MDA concentration were observed in the striatum of PD rats, comparing to the control group, combined with a significantly reduced activities of GR,SOD, Cu/ZnSOD and an increased GPX activity and MDA concentration in the hippocampus, a significantly lower GR, SOD, MnSOD, Cu/ZnSOD, and GST activities in the cerebral cortex. A significantly lower GR activity, higher CAT activity and MDA concentration in the thalamus and a significantly increased GR activity in the cerebellum were observed in PD rats compared to the corresponding control group. Oxidative stress in PD involves many brain structures and various antioxidant enzymes and oxidative status parameters become dysfunctional, depending on the area of the brain, which might reflect the complexity of the clinical symptoms of PD.

Effects of acute physical exercise on oxidative stress and inflammatory status in young, sedentary obese subjects.

Circulating oxidative stress and pro-inflammatory markers change after regular physical exercise; however, how a short session of acute physical activity affects the inflammatory status and redox balance in sedentary individuals is still unclear. Aim of this study is to assess antioxidant and inflammatory parameters, both at rest and after acute exercise, in sedentary young men with or without obesity. Thirty sedentary male volunteers, aged 20–45 (mean age 32 ± 7 years), were recruited, divided into 3 groups (normal weight: BMI < 25 kg/m2; overweight to moderate obesity: 25–35 kg/m2; severe obesity: 35–40 kg/m2), and their blood samples collected before and after a 20-min run at ~ 70% of their VO2max for the measurement of Glutathione Reductase, Glutathione Peroxidase, Superoxide Dismutase, Total Antioxidant Status (TAS) and cytokines (IL-2, IL-4, IL-6, IL-8, IL-10, IL-1α, IL-1β, TNFα, MCP-1, VEGF, IFNγ, EGF). Inter-group comparisons demonstrated significantly higher Glutathione Reductase activity in severely obese subjects in the post-exercise period (P = 0.036), and higher EGF levels in normal weight individuals, either before (P = 0.003) and after exercise (P = 0.05). Intra-group comparisons showed that the acute exercise stress induced a significant increase in Glutathione Reductase activity in severely obese subjects only (P = 0.007), a significant decrease in MCP-1 in the normal weight group (P = 0.02), and a decrease in EGF levels in all groups (normal weight: P = 0.025, overweight/moderate obesity: P = 0.04, severe obesity: P = 0.018). Altogether, these findings suggest that in sedentary individuals with different ranges of BMI, Glutathione Reductase and distinct cytokines are differentially involved into the adaptive metabolic changes and redox responses induced by physical exercise. Therefore, these biomarkers may have the potential to identify individuals at higher risk for developing diseases pathophysiologically linked to oxidative stress.

Salidroside as a Novel Protective Agent to Improve Red Blood Cell Cryopreservation.

Glycerol and trehalose have been widely examined as protective agents in the cryopreservation of red blood cells (RBCs). However, the effectiveness of these reagents alone on cell viability is moderate. Here, the addition of salidroside attenuated oxidative damage of sheep RBCs prior to and post cryostorage. The supplementation of salidroside to the cryopreservation media containing 10% glycerol improved RBC survival by approximately 61.1±4.8% vs 37.9±4.6%. A smaller effect was seen in RBCs cryopreserved in 300 mM trehalose where the addition of salidroside improved survival by 7.6±0.3%. Furthermore, the addition of salidroside to cold storage solution demonstrated a significant reduction of haemolysis after 4 days for RBCs loaded with either glycerol or trehalose, compared to cells incubated without salidroside. RBCs survival was 2-fold greater following freezing in trehalose, compared with glycerol. After 10 days, salidroside enabled a lower haemolysis of 16.7±1.3% compared to 29.0±8.4% for cells incubated without salidroside. However, salidroside had no effect on RBCs which had been frozen in glycerol as the resulting haemolysis rate by day 10 was approximately 60%. Salidroside increased glutathione reductase activity and decreased lactate dehydrogenase activity. Furthermore, it led to reduced carbonylation of proteins in both glycerol and trehalose loaded cells. Finally, no effect on lipid peroxidation was found in the glycerol loaded RBCs although this was reduced in RBCs loaded with trehalose and salidroside. The present findings confirm the potential use of salidroside as a novel protective agent in cryopreservation and refrigerated storage of sheep RBCs.