Significant Increase In Glutathione Peroxidase Activity Research Articles

Enzymatic responses reveal different physiological strategies employed by eurytolerant fish during extreme hot and cold cycling acclimation temperatures

Heat waves and cold snaps are projected to rise in magnitude, duration, interval, and harshness in the coming years. The current literature examining thermal impacts on the physiology of organisms rarely uses chronic, variable thermal acclimations despite the fact that climate change predictions project a more variable environment. If we are to determine species’ susceptibility to climate change, chronic and variable lab acclimations should be prioritized. Here, we acclimated the eurytolerant sheepshead minnow (Cyprinodon variegatus) to two extreme cycling thermal regimes: one warm [resting 27 °C with a spike to 33 °C for 8 h daily], one cold [resting 6.5 °C with a spike to 12 °C for 8 h daily], and three chronically stable conditions (10, 22, and 30 °C) for comparison. We measured enzymatic antioxidants (catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx)), total antioxidant capacity, lipid peroxidation (LPO) damage, and citrate synthase (CS) activity in white epaxial muscle. Of particular note, we found significant increases in log CAT activity and SOD concentration in the warm cycling temperatures, and significant increases in GPx activity in the cold cycling temperatures. We found no significant accumulation of LPO damage in any of our thermal acclimation treatments. Thus, sheepshead minnows demonstrate two particularly different mechanisms towards dealing with thermal variation in low and high temperatures. The enzymatic differences between low and high cycling temperatures may define pathways of eurytolerant organisms and how they may survive predicted variability in thermal regimes.

Plasma lipids, lipid peroxides and antioxidant system in osteoarthritic patients underwent spa therapy

Objective: The molecular processes underlying degenerative cartilage disease ''osteoarthritis, OA'' are not fully known.. Although oxidative stress causes cell damage in various tissues, there is not enough evidence for the involvement of oxidative stress in degenerative joint diseases. On the other hand, various spa therapies such as balneotherapy, mud, mineral water, and sulfur bath have long been used for treating osteoarthritis. This study aimed to investigate the effect of spa therapy with balneotherapy on oxidant/antioxidant status and lipid levels. Material and Methods: This prospective cross-sectional study was conducted on 28 osteoarthritis patients who had spa therapy at Bursa Military Hospital, Turkey. Osteoarthritis patients between 45-70 years who had no contraindications to spa therapy were eligible for inclusion in the study. Spa therapy included balneotherapy with acratothermal water, physical therapy modalities, and mild exercise for 15 days. Blood samples were obtained before and after the treatment cycle to determine the patients' possible changes in oxidant/antioxidant status and lipid profiles. Serum malondialdehyde (MDA), total thiol (T-SH) levels, total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx) activity, and plasma lipids were measured. Results: We found a statistically nonsignificant decrease in MDA levels and a significant increase in GPx activity. Whereas plasma lipids, T-SH levels, TAC, and SOD activity remained unchanged. Conclusion: We may suggest that different mechanisms may play a role in the beneficial effects of spa therapy with balneotherapy in OA besides stimulation of GPx activity.

Extraction and Identification of Two Flavonoids in Phlomoides hyoscyamoides as an Endemic Plant of Iran: The Role of Quercetin in the Activation of the Glutathione Peroxidase, the Improvement of the Hydroxyproline and Protein Oxidation in Bile Duct-Ligated Rats.

Cholestatic liver disease, a serious chronic condition that develops progressive hepatic degeneration through free radicals. The present study was designed to extract and identify two flavonoids in Phlomoides hyoscyamoides plant, native to Iran and evaluate the role of quercetin identified on the liver injury among bile ductligated rats. This study was conducted on 25 male Wistar rats within three groups of sham control, mere bile duct-ligated, and bile duct-ligated with quercetin. The bile duct-ligated animals received quercetin at a dose of 50 mg/kg/day for 10 days, followed by biochemical tests, oxidative stress markers, activity of antioxidant enzymes and hematoxylin and eosin staining. Molecular docking was used to explore the interactive behavior of quercetin with glutathione peroxidase. According to analyses of the obtained extract, two main active ingredients of P. hyoscyamoides were rutin and quercetin. Bile duct-ligated group showed a significant liver necrosis, a clear increase in plasma and tissue oxidative stress parameters, and a decrease in glutathione peroxidase activity as compared to sham control group. Quercetin injection in bile duct-ligated rats resulted in significant decrease in hydroxyproline, protein carbonyl and histopathologic indexes and significant increase in glutathione peroxidase activity (P-value≤0.05). Based on the molecular docking, the quercetin was able to regulate the glutathione peroxidase activity. The quercetin acts as an enzyme inducer by renewing the glutathione peroxidase activity and inhibiting the oxidation of proteins and hence decreases the oxidative stress. These results could be a sign of confirming the positive role of quercetin in attenuating the liver damage and degeneration.

Hydrotherapy in the evaluation of enzymatic antioxidants in an elderly population

Abstract Introduction Oxidative stress is the imbalance between reactive species produced in the body during metabolic reactions and antioxidant agents that have the ability to neutralize or prevent the formation of these species. One of the effects of oxidative stress is the normal and physiological process of cell aging that arises from the accumulation of tissue damage caused by free radicals. Objectives To assess whether the activity of enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GR) are influenced by the hydrotherapy sessions. Methodology 37 subjects aged 60 years old and above, of both genders, were divided into two groups (experimental and control). The experimental group underwent 15 hydrotherapy sessions supervised by a physical therapist. Two peripheral venous blood samples were collected at two different times: T0, instant before the intervention and T1, instant after the last session. The activity of SOD, GPx and GR enzymes were determined, respectively, with the Ransod superoxide dismutase, Ransel glutathione peroxidase and glutathione reductase commercial kits, from Randox Laboratories Limited, United Kingdom. The assay was performed as described in the kits and the sample results were obtained by spectrophotometric reading. Results SOD activity at T1 tended to decrease slightly compared to T0 (1437.64 ± 593.46 vs 1421.41 ± 705.39 U/g Hb). At T1, there was a statistically significant increase in GPx activity (48.14 ± 17.22 vs 57.72 ± 19.99 U/g Hb) and in GR activity (78.44 ± 21.26 vs 100.18 ± 30.85 U/L). Regarding gender, both genders tended to have higher values of GPx and GR at T1. Conclusion According to the obtained results, we conclude that the practice of hydrotherapy presents as a positive stimulus in the antioxidant activity of aged individuals suggesting that a regular and moderate practice of exercise induces a higher quality of life.

The Effect of Persistent Heavy Metal Exposure on Some Antioxidant Enzyme Activities and Lipid Peroxidation of the Freshwater snail, Lymnaea natalensis

This study investigated the effect of persistent heavy metal exposure on the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) of the freshwater snail, Lymnaea natalensis. Malondialdehyde (MDA) levels were also measured as an index of lipid peroxidation. The snails were exposed to cadmium, copper, lead and mercury for a total of 28days at 0.1mg/L, 0.1mg/L, 0.2mg/L and 0.1mg/L respectively. Samples were collected at 1, 7, 14, 21 and 28days intervals. Analysis of SOD showed significant initial increases in enzyme activity following exposure to copper, lead and mercury, while cadmium exposures caused increases from Day 14 onwards. Copper, cadmium and lead caused significant initial increases in CAT activity and mercury caused an increase only on Day 28. Copper caused a significant increase in GPx activity on Day 28 while MDA levels diminished significantly at Days 7-28. Similarly, cadmium caused significant increases of GPx activity on Day 28 whereas MDA levels were significantly reduced. Lead also caused a significant increase in GPx activity on Days 14-28 whilst no significant changes occurred in MDA levels. Mercury exposures caused significant increases in GPx activity on Days 7 and 21, whilst MDA levels were significantly reduced on Days 7 and 14. These findings suggest that persistent exposure of snails to heavy metals induces the antioxidant defence system, and decreases lipid peroxidation.

Powders with small microparticle size from Hedera helix and Scrophularia nodosa exhibited high preventive antioxidant activity against H2O2-induced oxidative stress in mouse primary spleen cells.

The purpose of this study was to examine the effects of powder particle size on the cytoprotective and antioxidant activity of Hedera helix (HH) and Scrophularia nodosa (SN), two medicinal plants more commonly known as ivy and figwort, against H2O2-induced oxidative stress in mouse primary spleen cells. Thus, the preventive effects of powders of 3 different granulometric classes (50-100μm, 100-180μm and 180-315μm) and those of the hydroethanolic (HE) extract from HH and SN on oxidative stress were compared by monitoring reactive oxygen species (ROS) formation, malondialdehyde (MDA) production, and the activity of enzymatic antioxidants including catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx). Results showed that pretreatment with the 3 fine powders from both plants generally offered to H2O2-exposed spleen cells, a protection against oxidative stress, highlighted by a significant decrease of both ROS formation and the level of MDA (p<0.001), and a significant increase of GPx activity (p<0.05). The two superfine powders (i.e. 50-100μm and 100-180μm), at 250μg/mL, were more effective in modulating all oxidative stress markers studied than both HE extracts (p<0.01), and the powder with the highest particular size (i.e., 180-315μm) (p<0.01). Compared to untreated cells, our results suggest that pretreatment with powders, in particular the superfine fractions, has relatively restored the levels of antioxidant-related enzymes including GPx, CAT and SOD. In summary, our results suggest differential effects between the 3 different fine powders studied, with the best cytoprotective and antioxidant activities being in favor of the superfine powders.

The association between follicle stimulating hormone and glutathione peroxidase activity is dependent on abdominal obesity in postmenopausal women.

Menopause is frequently associated with an increase in visceral fat, thus modifying redox status by promoting oxidative damage and decreasing antioxidant defense systems. It is known that at higher concentrations estradiol has some antioxidant properties, while its decline in postmenopause is associated with pro-oxidant effects. However, the role of follicle stimulating hormone (FSH) in antioxidant defense in postmenopausal women is still not well elucidated. Therefore, we aimed to evaluate the potential complex association between visceral obesity, FSH and enzymatic antioxidant defense as measured by glutathione peroxidase (GPx) in postmenopausal women. A total of 150 postmenopausal women (mean age 56.6±4.8years), among them 50 normal weight and 100 overweight/obese, were included. GPx activity, FSH, luteinizing hormone, estradiol, total testosterone, cardiometabolic and anthropometric parameters, were determined. With increasing tertiles of serum FSH levels, significant increase in GPx activity (P=0.005) was found. Also, the highest number of overweight/obese subjects were in the group with the lowest FSH values (χ 2=14.9, P<0.001). After multiple linear regression analysis, the relationship between GPx and FSH disappeared, whereas only higher waist circumference (β=-0.218, P=0.045) predicted lower FSH level (adjusted R 2=0.227). Higher GPx activity is associated with higher FSH level, but abdominal obesity may be the underlying determinant of this relationship.

The protective role of curcumin on testicular tissue after hindlimb ischemia reperfusion in rats.

The aim of this study was to investigate the role of curcumin in remote testicular injury caused by hindlimb ischemia reperfusion (IR). Forty male Wistar rats were allocated to four groups: sham (G1), sham + curcumin (G2), IR (G3) and IR + curcumin (G4). Curcumin 200 mg/kg was administered intraperitoneally 2 h prior to IR induction. Lower extremities were subjected to IR induced by infrarenal aortic occlusion for 2 h, followed by 6 h of reperfusion. The rats were euthanized and the testes were removed. Glutathione peroxidase (GPx), superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT) and myeloperoxidase (MPO) activities and histopathological damage scores were determined in right testicular tissues. Left testes were used for wet/dry weight ratio measurement. Activities of SOD and CAT in testicular tissues were significantly decreased by IR, but curcumin pretreatment increased these levels (P < 0.05). MPO activity in testicular tissues in the G3 was significantly higher than in the G4 (P < 0.05). Significantly increased MDA levels in testicular tissues by IR were decreased by curcumin pretreatment (P < 0.05). Testis tissues showed a significant increase in GPx activity compared to the IR group when curcumin was applied. The wet/dry weight ratio of testicular tissues in the G3 was significantly higher than in the other groups (P < 0.05). In addition, specimens from the G3 had a significantly greater histological injury than those from the G4 (P < 0.05). There were no significant differences in tissue MDA, MPO, SOD, CAT and GPx activities, histological changes and wet/dry weight ratio between the G1, G2 and G4. According to the findings, we conclude that curcumin has preventive effects in the testicular injury induced by hindlimb IR in rats.

Efficacy of selected treadmill training programme on oxidative stress in adolescents with Down syndrome

The aim of this study was to assess the efficacy of an electronic treadmill exercise training programme on malondialdehyde (MDA) as a marker for lipid peroxidation and the antioxidant enzyme glutathione peroxidase (GPx) in adolescents with Down syndrome. The study was carried out on 30 adolescent males with Down syndrome, ranging in age from 15 to 18 years, with 30 healthy subjects as a control group. Clinical examination, anthropometric measurements and determination of GPx activity and MDA before and after exercise were done. A treadmill training programme was performed for 12 weeks. Our data showed a significant increase in GPx activity and decrease in serum level of MDA in Down syndrome individuals after treadmill exercise for 3 months. Exercise promotion for adolescents with Down syndrome requires attention to motivators and facilitators of exercise adherence as it may limit risk of increased neurological consequences associated with oxidative stress and improve quality of life.

Antioxidative system in the erythrocytes of preterm neonates with sepsis: the effects of vitamin E supplementation

Vitamin E is routinely supplemented to preterm babies, including those with neonatal sepsis. Our aim was to examine the effects of neonatal sepsis and vitamin E on antioxidative system (AOS) in the blood. A prospective, randomized, open label study involved 65 preterm neonates (control/sepsis - 34/31), which were divided into two subgroups - non-supplemented and supplemented with vitamin E (25 IU/day for 60 days). The activities of superoxide dismutase, catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) were determined in erythrocytes at days 0, 30, and 60, following sepsis diagnosis. There was no difference in the activity of AOS between controls and neonates with ongoing sepsis. At 60 days, septic neonates showed higher CAT activity compared to controls (P = 0.027), and lower GPx activity compared to 0 days (P = 0.022). The later was mitigated by vitamin E, which on the other hand provoked lower GPx activity at 30 days, compared to untreated septic neonates (P = 0.014). In addition, vitamin E suppressed GR activity in septic neonates (P = 0.025 and P = 0.017 at 30 and 60 days). Finally, vitamin E supplementation in control neonates provoked a significant increase of GPx activity (P = 0.015 at 60 days). The absence of altered redox settings in the blood of neonates during sepsis episode, and vitamin E-provoked decrease in the activity of some components of AOS, suggest that the supplementation of vitamin E in these patients might not be rational.

Effect of Light at Night on oxidative stress markers in Golden spiny mice (Acomys russatus) liver

Light at Night (LAN) suppresses melatonin (MLT) production, and effects metabolism, hormone secretion, gene expression and enzyme activity. Changes in antioxidant enzymes glutathione peroxidase (GPx) and superoxide dismutase (SOD), can be used as an indication for oxidative stress level. We assayed activity and expression of these enzymes in the liver of Acomys russatus exposed to LAN and treated with MLT. Short day (SD)-acclimated A. russatus, was exposed to 30min of LAN for two, seven or 21 nights. MLT impact was assessed simultaneously with two and seven nights of LAN exposure. GPx and SOD activities were measured. Gpx1 expression was evaluated by RT-PCR. There was a significant increase in GPx activity following LAN exposure for all acclimation durations, GPx activity was elevated after two nights of LAN and MLT treatment, Gpx1 expression was elevated by MLT after seven nights of LAN. SOD activity increased after two nights of LAN in MLT-treated A. russatus, GPx activity increased with the duration of LAN acclimation, indicating changes in liver redox status. Our results suggest that LAN is a stressor that influences oxidative stress. As in the other studies, MLT increases antioxidant activities, presumably attenuating stress response, in order to restore homeostasis.

Correlation Between Mastitis Pathogenic Bacteria and Glutathione Peroxidase Activity in Cows Milk

Antioxidant activity of milk is due to the presence of antioxidant anzymes such as catalase, lactoperoxidase, glutathione-peroxidase, xanthin/oxidase, or vitamins and provitamins such as retinoils and carotenoids, tocopherols and ascorbic acid. The aim of this study was to establish a correlation between pathogenic bacteria type involved in cows mastitis and glutathione-peroxidase activity in milk. Determination of the enzyme activity was performed on milk samples, before and after germs inoculation with various dilutions of Streptoccocus spp., Staphylococcus spp. Pseudomonas spp. Escherichia spp. Candida spp. To show the glutathione-peroxidase activity during milk bacteria multiplication, an in vitro protocol for germs development in liquid medium (Muller Hinton agar with milk) was performed. Glutathione peroxidase activity in milk samples was performed on skimmed milk, using a commercial kit (Ransel, Randox Laboratories) and semiautomatic biochemistry analyzer MasterPlus Screen. We observe the fact that development of the pathogenic bacteria in milk is accompanied by a significant increase of glutathione-peroxidase activity. The level of enzyme activity depends on the type of bacteria. The highest values were in milk samples inoculated with Escherichia coli, values that exceeded 10 times the values of normal milk samples. For Streptococcus viridians, Pseudomonas aeruginosa and Candida spp. were established modest results, the lowest values being registered from samples containing Staphylococcus aureus.

Influence of flavonoid extracts from celery on oxidative stress induced by dichlorvos in rats

The present work was to investigate the effects of flavonoid extracts from celery on oxidative stress induced by dichlorvos (DIC) in male Wistar rats maintained on a normal diet. The rats were given DIC through intragastric administration by the dose of 7.2 mg/kg·body weight (bw)/day and additionally added 5% flavonoid extracts to the diet for 4 weeks continuously. The activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione-S-transferase (GST) and the content of malondialdehyde (MDA) in livers of rats were measured at the end of the experiment. Under the influence of DIC, there were significant decrease in the activities of SOD, CAT and GST and significant increase in GPx activity and MDA content. The results also showed that the activities of SOD, GST and CAT in the DIC-treated group declined significantly when compared with the flavonoid extracts group and the DIC + flavonoid extracts group, respectively. With regard to GPx activity and MDA content, significant increase were showed in the DIC-treated group in comparison to those in the flavonoid extracts group and the DIC + flavonoid extracts group, respectively. The observations presented lead us to conclude the harmful effects of DIC during the exposure and the protective role of flavonoids in minimizing these effects.

Zofenopril in the treatment of patients with arterial hypertension and stable coronary heart disease: effects on oxidative stress and flowdependent vasodilatation

Aim. To compare the effects of ACE inhibitors zofenopril and perindopril on endothelial function and oxidative stress (OS) in patients with stable CHD and AH. Material and methods. In total, 40 patients with stable CHD (Functional Class II-III effort angina) and Stage 1-2 AH received zofenopril (7,5-30 mg/d; mean dose 18,6±8,8 mg/d; n=17) or perindopril (2-8 mg/d; mean dose 4,1±2,1 mg/d; n=23) for 12 weeks. At baseline and in the end of the study, all patients underwent reactive hyperemia test (RHT), to assess flow-dependent vasodilatation of brachial artery, and the measurement of OS parameters (malone dialdehyde, MDA, in low-density lipoproteins, MDALDL) and antioxidant parameters (superoxide dismutase (SOD) and glutathione peroxidase (GPO) activity in erythrocytes).Results. In both groups, a similar reduction in systolic and diastolic blood pressure levels was observed. In the zofenopril group, a significant elevation in brachial artery diameter increase during RHT, a significant increase in GPO activity, and some reduction in MDALDL levels were observed, which points to antioxidant system (AOS) activation and OS reduction. No similar changes of these parameters were observed in the perindopril group. Conclusion. In patients with stable CHD and AH, zofenopril, but not perindopril, reduced OS severity and increased AOS system activity, which was associated with improved endothelial-dependent vasodilatation.

Lipoic acid increases glutathione peroxidase, Na+, K+-ATPase and acetylcholinesterase activities in rat hippocampus after pilocarpine-induced seizures?

In the present study we investigated the effects of lipoic acid (LA) on acetylcholinesterase (AChE), glutathione peroxidase (GPx) and Na+, K+-ATPase activities in rat hippocampus during seizures. Wistar rats were treated with 0.9% saline (i.p., control group), lipoic acid (20 mg/kg, i.p., LA group), pilocarpine (400 mg/kg, i.p., P400 group), and the association of pilocarpine (400 mg/kg, i.p.) plus LA (20 mg/kg, i.p.), 30 min before of administration of P400 (LA plus P400 group). After the treatments all groups were observed for 1 h. In P400 group, there was a significant increase in GPx activity as well as a decrease in AChE and Na+, K+-ATPase activities after seizures. In turn, LA plus P400 abolished the appearance of seizures and reversed the decreased in AChE and Na+, K+-ATPase activities produced by seizures, when compared to the P400 seizing group. The results from the present study demonstrate that preadministration of LA abolished seizure episodes induced by pilocarpine in rat, probably by increasing AChE and Na+, K+-ATPase activities in rat hippocampus.

Red blood cell antioxidant levels in Wuchereria bancrofti infection

The elimination of microfilariae of Wuchereria bancrofti is probably mediated by free radicals. Red cell catalase (C), glutathione peroxidase (GPX), and superoxide dismutase (SOD) activity levels were measured as an indirect method of assessing blood oxidant status in 29 asymptomatic microfilaraemics, 29 “endemic normals”, and 29 controls living in a non-endemic area. Changes in the activity of these enzymes were also compared over a one month period in 22 asymptomatic microfilaraemics randomised to receive either single dose or 14 day treatment with diethyl carbamazine citrate (DEC). Red cell GPX activity levels were significantly higher in “endemic normals” when compared to mf positive cases and non-endemic controls. An early and significant increase in GPX activity (on days 3, 7 and 14 compared to pretreatment levels, p<0.01) was observed after DEC in both treatment groups. Increases in the activity of catalase and SOD became significant only on days 14 and 30 respectively. The percentage reduction in microfilaraemia correlated significantly with the percentage increase in GPX activity levels ( R 2=0.58, p=0.6×10 −5 ). Our results may suggest a role for GPX related oxidant species in the elimination of microfilariae.

α-Melanocyte-stimulating Hormone Reduces Impact of Proinflammatory Cytokine and Peroxide-generated Oxidative Stress on Keratinocyte and Melanoma Cell Lines

We have previously shown that alpha-melanocyte-stimulating hormone (alpha-MSH) can oppose tumor necrosis factor alpha activation of NF-kappaB (1-2 h) and intercellular adhesion molecule 1 up-regulation (mRNA by 3 h and protein by 24 h) in melanocytes and melanoma cells. The present study reports on the ability of four MSH peptides to control intracellular peroxide levels and glutathione peroxidase (GPx) activity in pigmentary and nonpigmentary cells. In human HBL melanoma and HaCaT keratinocytes tumor necrosis factor alpha and H(2)O(2) both activated GPx in a time- and concentration-dependent manner (by 30-45 min). alpha-MSH peptides were found to inhibit the stimulated GPx activity and had biphasic dose-response curves. MSH 1-13 and MSH [Nle(4)-d-Phe(7)] achieved maximum inhibition at 10(-10) and 10(-12) m, respectively. Higher concentrations (10-100 fold) of MSH 4-10 and MSH 11-13 were required to produce equivalent levels of inhibition. alpha-MSH was also capable of reducing peroxide accumulation within 15 min, and again this inhibition was biphasic. The data support a role of alpha-MSH in acute protection of cells to oxidative/cytokine action that precedes NF-kappaB and GPx activation. The rapidity and potency of the response to alpha-MSH in pigmentary and nonpigmentary cells suggest this to be a central role of this peptide in cutaneous cells.