Erythrocyte Antioxidant Enzyme Activities Research Articles

Erythrocyte antioxidant enzyme activities and lipid peroxidation in the erythrocyte membrane of stainless-steel welders exposed to welding fumes and gases

The erythrocyte antioxidant system (superoxide dismutase, SOD; catalase, CAT) and lipid peroxidation (malondialdehyde, MDA) in the erythrocyte membrane were studied in workers continously exposed to welding fumes and gases, which are thought to be oxidant pollutants. Thirty-five welders using the manual metal arc method on stainless steel and 30 controls were studied. Plasma chromium (Cr), manganese (Mn), and cupper (Cu) levels were determined by atomic absorption spectrophotometer (AAS). The erythrocyte antioxidant system activity and lipid peroxidation in the erythrocyte membrane were evaluated. Not only the possible effects of welding fumes but also the effects of smoking were considered. The plasma concentrations of Cr, Mn, and Cu for the exposed welders were significantly higher compared to the control subjects ( p<0.001, p<0.01, p<0.001, respectively,). The erythrocyte CAT ( p<0.05) and SOD ( p<0.05) enzyme activities were significantly higher in the welders but there were not any significant changes in the MDA levels which reflect the lipid peroxidation in the erythrocyte membrane ( p>0.05). Smoking has increased the SOD activity in both controls ( p<0.05) and welders ( p<0.01) and increased the CAT activity in control subjects ( p<0.05). Moreover, regardless of smoking, there were some significant correlations between the duration of the exposure to welding fumes and antioxidant defence system (SOD: p<0.05; CAT: p<0.05). The synergistic effects of smoking and other risk factors (welding fumes and gasses), which had been shown previously by some clinical data should also be taken into account. As a consequence, the welders should be warned and informed of the synergistic effects of smoking on the adverse effect of welding fumes and gases.

Multivitamin-Mineral Supplementation Prevents Lipid Peroxidation during “The Marathon des Sables”

Objective: We investigated the effect of a moderate mutivitamin and mineral supplementation containing mainly vitamin C (150.0 mg.day−1), vitamin E (24.0 mg.day−1) and β-carotene (4.8 mg.day−1) prior to and during an extreme running competition -the Marathon des Sables (MDS)- that consisted of six long races in the desert.Methods: Seventeen athletes participated in our double blind, placebo-controlled study. Blood samples were collected prior to the supplementation i.e. three weeks before the competition (D-21), two days prior to the MDS (D-2), after the third race (D3) and at the end of the competition (D7). Erythrocyte antioxidant enzyme activity (glutathione peroxidase (GPx), superoxide dismutase (SOD)), erythrocyte glutathione level (GSH), plasma non-enzymatic antioxidant status (uric acid, vitamin C, α-tocopherol, retinol, β-carotene), markers of plasma lipid peroxidation (thiobarbituric reactive substances (TBARS)), reactive carbonyl derivatives (RCD) and membrane damage (creatine kinase and lactate dehydrogenase activities) were measured.Results: In both groups, GSH levels, uric acid levels and membrane damage significantly increased during the competition while SOD activity significantly decreased. In Supplemented group, plasma α-tocopherol, β-carotene and retinol levels significantly increased after three weeks of supplementing. In contrast to Placebo group, α-tocopherol, vitamin C and retinol levels were significantly affected by the competition in Supplemented group. Moreover, no increase in TBARS was observed in Supplemented group during the competition, whereas TBARS significantly increased at D3 in the placebo group.Conclusion: The moderate multivitamin-mineral supplementation prevented the transient increase in TBARS levels during this extreme competition.

Effects of α-Tocopherol and Mixed Tocopherol Supplementation on Markers of Oxidative Stress and Inflammation in Type 2 Diabetes

Vitamin E isomers may protect against atherosclerosis. The aim of this study was to compare the effects of supplementation with either alpha-tocopherol (alphaT) or mixed tocopherols rich in gamma-tocopherol (gammaT) on markers of oxidative stress and inflammation in patients with type 2 diabetes. In a double-blind, placebo-controlled trial, 55 patients with type 2 diabetes were randomly assigned to receive (500 mg/day) (a) alphaT, (b) mixed tocopherols, or (c) placebo for 6 weeks. Cellular tocopherols, plasma and urine F(2)-isoprostanes, erythrocyte antioxidant enzyme activities, plasma inflammatory markers, and ex vivo assessment of eicosanoid synthesis were analyzed pre- and postsupplementation. Neutrophil alphaT and gammaT increased (both P <0.001) with mixed tocopherol supplementation, whereas alphaT (P <0.001) increased and gammaT decreased (P <0.005) after alphaT supplementation. Both alphaT and mixed tocopherol supplementation resulted in reduced plasma F(2)-isoprostanes (P <0.001 and P = 0.001, respectively) but did not affect 24-h urinary F(2)-isoprostanes or erythrocyte antioxidant enzyme activities. Neither alphaT nor mixed tocopherol supplementation affected plasma C-reactive protein, interleukin 6, tumor necrosis factor-alpha, or monocyte chemoattractant protein-1. Stimulated neutrophil leukotriene B(4) production decreased significantly in the mixed tocopherol group (P = 0.02) but not in the alphaT group (P = 0.15). The ability of tocopherols to reduce systemic oxidative stress suggests potential benefits of vitamin E supplementation in patients with type 2 diabetes. In populations with well-controlled type 2 diabetes, supplementation with either alphaT or mixed tocopherols rich in gammaT is unlikely to confer further benefits in reducing inflammation.

The effects of diazinon on lipid peroxidation and antioxidant enzymes in rat erythrocytes: role of vitamins E and C

Reactive oxygen species caused by organophosphates may be involved in the toxicity of various pesticides. Therefore, in this study, we aimed to investigate the effects of acute exposure to organophosphate insecticide diazinon (DI) and possible ameliorating role of vitamins E and C, with the following parameters: lipid peroxidation (LPO) and the activity of the glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) in rat erythrocytes. The experimental groups were arranged as control group, DI-treated group (DI) and DI + vitamin E + vitamin C-treated group (DI + Vit). DI + Vit groups were treated orally with a single dose of 335 mg/kg DI body weight. Vitamins E and C were injected at doses of 150 mg/kg body weight intramuscular (in) and 200 mg/kg body weight intraperitoneal (ip), respectively, 30 min after the treatment of DI in DI + Vit group. Blood samples were taken 24 h after the DI. The results showed that DI administration caused to increase in LPO and the activities of SOD and GSH-Px enzymes in erythrocytes. Also, the combination of vitamins E and C decreased LPO and the activities of GSH-Px and SOD compared with the DI group. In conclusion, although treating rats with single dose DI increases LPO and antioxidant enzyme activities in erythrocytes, vitamins C and E combination can reduce LPO caused by DI.

Oxidative Stress in Half and Full Ironman Triathletes

Ultraendurance athletes who maintain a very high volume of exercise may, as a result of greater production of reactive oxygen species (ROS), be particularly susceptible to oxidative damage. This study sought to examine and compare pre- and postrace markers of oxidative stress in ultraendurance athletes training for, and competing in, either a half or a full Ironman triathlon. Resting and postexercise blood was sampled from 16 half Ironman triathletes, 29 full Ironman triathletes, and age-matched, relatively inactive controls. Blood was analyzed for markers of oxidative stress (malondialdehyde (MDA) concentration) and antioxidant status (glutathione peroxidase (GPX), catalase (CAT), and superoxide dismutase (SOD) activities). Compared with controls, the half Ironman triathletes had significantly (P < 0.001) higher erythrocyte GPX activity at rest, whereas the Ironman triathletes had significantly (P < 0.05) lower resting plasma MDA and significantly (P < 0.05) greater resting activities of GPX and CAT compared with controls. As a result of the half Ironman triathlon, there was a significant (P < 0.05) increase in MDA and significant (P < 0.05) decreases in erythrocyte GPX, SOD, and CAT activities. These changes also occurred in response to the Ironman triathlon; MDA significantly (P < 0.05) increased, and there were significant (P < 0.001) decreases in GPX, CAT, and SOD activities. Users of antioxidant supplements in both the half and full Ironman races had significantly (P < 0.05) elevated MDA after races compared with nonsupplementers. The present investigation indicates that training for and competing in half and full Ironman triathlons has different effects on erythrocyte antioxidant enzyme activities and oxidative stress.

Time-relative changes in the erythrocyte antioxidant enzyme activities and their relationship with glasgow coma scale scores in severe head injury patients in the 21-day posttraumatic study period

Reactive oxygen species are indicated to play a prime role in the pathophysiology of brain damage following a severe head injury (SHI). The current study was designed to understand the time-relative changes and relationship between erythrocyte antioxidant enzyme activities and Glasgow Coma Scale (GCS) scores of SHI patients in the 21-day posttraumatic study period. The study included 24 SHI patients and 25 age- and sex-matched normal controls (NC). Activities of superoxide dismutase (SOD), glutathione reductase (GR) and glutathione peroxidase (GSH-Px) were assayed in these patients and controls. The GCS scores of these patients were also recorded for the comparative study. Venous blood samples were collected on day 7 (D7) and D21 from SHI patients and NC for the assay of SOD, GR and GSH-Px activities. These changes were correlated with age and changes in GCS scores of patients. A one-way analysis of variance (ANOVA) was used to compare mean values of each parameter between group 1 (NC), group 2 (D7 changes in SHI patients) and group 3 (D21 changes in SHI patients). ANOVA was followed by Bonferroni post hoc tests. The Pearson correlation was applied to correlate between the antioxidant parameters and age and GCS scores of these patients. A significant increase in erythrocyte SOD and GSH-Px activities was observed in group 3 as compared to groups 1 and 2. The increase in GSH-Px activity was significant in group 2 as compared to group 1. Although not significant, there was an increase in mean GR activity in groups 2 and 3 as compared to group 1. These findings indicate that SHI patients have shown significantly enhanced erythrocyte SOD and GSH-Px activities during the 21-day posttraumatic study period.

Effect of Intravenous Iron Sucrose on Oxidative Stress in Peritoneal Dialysis Patients

Aim. Intravenous iron therapy is an accepted treatment for patients receiving hemodialysis and continuous ambulatory peritoneal dialysis (CAPD). Studies have found enhanced oxidative stress in hemodialysis patients receiving intravenous iron, but there are no clinical data for CAPD patients. The aim of the current study was to investigate the effect of 100 mg of intravenous iron-sucrose on the erythrocyte (RBC) antioxidant enzymes (namely, superoxide dismutase [SOD], catalase [CAT], and glutathione peroxidase [GSHPx]) and plasma malondialdehyde (MDA), an oxidant molecule, in CAPD patients. Methods. Twelve CAPD patients receiving maintenance intravenous iron-sucrose were recruited. After a 12-hour fast, blood samples were taken for hemoglobin, iron, ferritin, and high-sensitivity C-reactive protein (hsCRP), and for baseline activities of erythrocyte antioxidant enzymes (i.e., SOD, CAT, GSHPx) and the plasma oxidant molecule, MDA. 100 mg iron-sucrose was infused over 30 minutes. Blood samples taken during (i.e., 15 minutes after commencement of infusion) and after (i.e., at 30 minutes, 60 minutes, and 6 hours after commencement) the infusion were taken for measurement of plasma iron, ferritin, TSAT, RBC SOD, CAT, GSHPx, and plasma MDA. Results. Plasma iron and transferrin saturation elevated significantly during infusion (p < 0.05). There was no significant change in erythrocyte SOD, CAT, GSHPx, or in MDA activities. There was a reduction of GSHPx activity at the 30th minute (from 153.69 ± 66.69 to 123.68 ± 25.50 mU/mL), but it was not statistically significant. The patients were grouped according to baseline ferritin (100–400 and 400–800 ng/mL); 60th-minute MDA was significantly higher in the latter group (p < 0.05). There was no correlation between hsCRP and oxidant-antioxidant balance. No correlation was noted between RBC antioxidant enzymes or plasma oxidant molecule and ferritin levels. Conclusion. There are no acute deteriorating effects from a 100 mg of intravenous iron-sucrose in CAPD patients with optimal iron stores. This dose may be applied safely in CAPD patients.

Effects of Calcitonin, Risedronate, and Raloxifene on Erythrocyte Antioxidant Enzyme Activity, Lipid Peroxidation, and Nitric Oxide in Postmenopausal Osteoporosis

The aims of this study were to compare erythrocyte antioxidant enzyme activities, lipid peroxidation, and nitric oxide levels (NO) in women with postmenopausal osteoporosis (PMO) and non-porotic postmenopausal healthy controls and to assess the relationship between bone mineral density and these oxidant/antioxidant parameters. Additionally, in vivo effects of three different anti-osteoporotic drugs, calcitonin, risedronate and raloxifene, on the erythrocyte oxidant-antioxidant status in women with PMO were also assessed. Postmenopausal women aged 40-65 years and without previous diagnosis or treatment for osteoporosis and independent in activities of daily living were included. Bone mineral density was measured at the lumbar spine and proximal femur using DXA. Erythrocyte enzyme activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and lipid peroxidation end-product malondialdehyde (MDA) and nitrite/nitrate levels, by product of NO, were assessed. Fifty-nine women with PMO were included (mean age 56.7 years), 44 completed course of therapy and were analyzed. Twenty-two non-porotic healthy women (mean age 55.8 years) were included as controls. Patients had significantly lower CAT and GSH-Px enzyme activity and higher levels of MDA and NO than non-porotic healthy controls. Proximal femur BMD measurements significantly correlated with NO levels. QUALEFFO scores improved in different levels with these short-term treatments. In all treatment groups, erythrocyte MDA levels significantly decreased; moreover, risedronate reduced NO levels and raloxifene enhanced CAT enzyme activity. Oxidative stress plays an important role in the pathogenesis of PMO. Studied drugs had ultimate effects on reducing lipid peroxidation. Raloxifene also had potent effects in the enhancement of antioxidant defense system.

Protective role of l-ascorbic acid on antioxidant defense system in erythrocytes of albino rats exposed to nickel sulfate

In this experimental study, we investigated whether L-ascorbic acid has any influence on the blood antioxidant defense system, lipid peroxidation and hematological parameters of the albino rats exposed to nickel sulfate(NiSO4). Twenty four adult rats were divided into four groups of six animals in each group. The control rats were untreated and comprised Group I. Group II rats were administered nickel sulfate (2.0 mg/100 g b.wt.; intraperitonially, i.p.). Group II rats were treated orally L-ascorbic acid (50 mg/100 g b.wt.) and Group IV rats were given both nickel sulfate and L-ascorbic acid simultaneously on alternate days until the tenth dose. The hematological parameters were assessed: red blood corpuscle counts, packed cell volume %, hemoglobin concentration, white blood corpuscle counts and platelets count decreased significantly and clotting time increased significantly in nickel treated rats. We also observed increase malondialdehyde (MDA) and decrease glutathione level (GSH) in erythrocytes of nickel treated rats. The activities of erythrocyte antioxidant enzymes like superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) were significantly increased in rats treated with nickel sulfate. Simultaneously treatment of L-ascorbic acid exhibited a possible protective role on the toxic effect of nickel sulfate on the hematological values, erythrocyte MDA and GSH concentrations as well as antioxidant enzymatic defense system.

Lipid peroxidation and antioxidant enzymes in children on maintenance dialysis

End-stage renal disease (ESRD) is associated with numerous complications, which may partly result from excessive amounts of reactive oxygen species and/or decreased antioxidant activity. The aim of the study was to evaluate lipid peroxidation (LP) in plasma and erythrocytes, erythrocyte antioxidant enzyme activity (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GSH-Px), and concentrations of Cu and Zn as cofactors of SOD and Se as a cofactor of GSH-Px in erythrocytes, plasma and in dialysis fluid in children with ESRD. In particular, we analyzed whether the modality of dialysis could modify oxidative stress parameters in children. To determine the influence of hemodialysis (HD) on oxidative stress, the measurements were also performed on HD children 20 min after the beginning of the dialysis session. Thirty-one patients participated in the study: group I with 10 children on continuous ambulatory peritoneal dialysis (CAPD), and group II with 21 on HD. The erythrocyte malondialdehyde concentrations (E-MDA), plasma MDA (P-MDA) and plasma organic hydroperoxide (OHP) in children from both groups were higher than in controls. E-MDA and P-MDA in HD before the session was lower compared to the values after 20 min of HD session (time T20). The activity of SOD, GSH-Px, CAT, concentrations of erythrocyte and plasma Se, Cu, Zn were lower in children with ESRD than in controls. In the HD group, the activity of GSH-Px, CAT, and levels of trace elements in erythrocytes and in plasma were diminished at time T20. In conclusion, increased oxidative stress occurs in children on maintenance dialysis, independent of dialysis modality. The activity of the enzymatic antioxidant defence system is highly reduced in red blood cells of pediatric dialysis patients. Children with ESRD exhibit lower trace element (Se, Cu, Zn) levels in plasma and erythrocytes as compared to healthy subjects. Oxidative stress is aggravated during every single HD session in children.

Association between dietary fat and antioxidant status of Tunisian type 2 diabetic patients

Background The antioxidant enzymes: superoxide dismutase (Cu/Zn SOD) and glutathione peroxidase (GSH-Px) provide a defense against the damage of cells by reactive oxygen species, which increased in diabetic state. It was demonstrated that dietary treatment could improve the antioxidant status in patients with type 2 diabetes mellitus. This study was undertaken to determine if erythrocyte Cu/Zn SOD and GSH-Px activities correlate with dietary nutrients in 35 selected type 2 diabetic patients (21 women and 14 men) without diabetic complications. Results We found that erythrocyte Cu/Zn SOD was diminished in patients with poor controlled diabetes and GSH-Px activity was significantly decreased in obese compared with non-obese type 2 diabetic patients (1.07±0.87 and 2.36±1.99 U/ml, respectively; P=0.024). Both erythrocyte Cu/Zn SOD and GSH-Px activities were positively correlated to erythrocyte ω3-polyunsaturated fatty acids (PUFA). In non-obese diabetic patients, only GSH-Px activity was correlated negatively to the fraction of linoleic acid (18:2 ω6) and arachidonic acid (20:4 ω6) in erythrocytes phospholipids. Conclusions The data of this study reveal that activities of erythrocyte antioxidant enzymes were altered in type 2 diabetic patients. Further studies are needed to determine if diet supplemented with ω3-PUFA is required to improve antioxidant defense system in diabetic state.

Correlation between glutathione peroxidase activity and anthropometrical parameters in adolescents with Down syndrome

Since we have recently found that regular exercise increased erythrocyte antioxidant enzyme activities such as glutathione peroxidase (GPX) in adolescents with Down syndrome, these programs may be recommended. This study was designed to assess the role of anthropometrical parameters as easy, economic and non-invasive biomarkers of GPX. Thirty-one adolescents with Down syndrome performed a 12-week training program. Three days after its ending, GPX activity and anthropometrical parameters were assessed. Pearson's correlation coefficient showed negative but significant association ( r = 0.49, p = 0.022) between GPX activity and waist circumference (WC). Body mass index (BMI) and waist-to-hip ratio (WHR) were not significant. We may conclude that anthropometrical parameters such as WC are easy to perform but not strongly associated to GPX activity. Further studies concerning other variables are needed.

N-3 Fatty acids modulate antioxidant status in diabetic rats and their macrosomic offspring

We investigated the role of dietary n-3 polyunsaturated fatty acids (n-3 PUFA) in the modulation of total antioxidant status in streptozotocin (STZ)-induced diabetic rats and their macrosomic offspring. Female wistar rats, fed on control diet or n-3 PUFA diet, were rendered diabetic by administration of five mild doses of STZ on day 5 and were killed on days 12 and 21 of gestation. The macrosomic (MAC) pups were killed at the age of 60 and 90 days. Lipid peroxidation was measured as the concentrations of plasma thiobarbituric acid reactive substances (TBARS), and the total antioxidant status was determined by measuring (i) plasma oxygen radical absorbance capacity (ORAC), (ii) plasma vitamin A, E and C concentrations, and (iii) antioxidant enzymes activities in erythrocytes. The plasma lipid concentrations and fatty acid composition were also determined. Diabetes increased plasma triglyceride and cholesterol concentrations, whereas macrosomia was associated with enhanced plasma cholesterol and triglyceride levels, which diminished by feeding n-3 PUFA diet. N-3 PUFA diet also reduced increased plasma TBARS and corrected the decreased ORAC values in diabetic rats and their macrosomic offspring. EPAX diet increased the diminished vitamin A levels in diabetic mothers and vitamin C concentrations in macrosomic pups. Also, this diet improved the decreased erythrocyte superoxide dismutase and glutathione peroxidase activities in diabetic and macrosomic animals. Diabetes and macrosomia were associated with altered lipid metabolism, antioxidant enzyme activities and vitamin concentrations. N-3 PUFA diet improved hyperlipidemia and restored antioxidant status in diabetic dams and MAC offspring.

Reactive oxidant species in asthma

This overview summarizes some recent studies on the balance of oxidants to antioxidants in patients with asthma. The aim of the review is to compare studies on the changes in oxidants/antioxidants in stable asthma or in acute exacerbation of asthma. Our review of the recent literature in this field seems to indicate conflicting findings. Increased release of reactive oxygen species such as superoxide anion and hydrogen peroxide has been reported in exhaled breath condensates and from circulating granulocytes, and from the bronchoalveolar lavage cells of patients with asthma. In asthma, bronchial obstruction is associated with an increased spontaneous and stimulus-induced production of oxygen free radicals. The primary defense against reactive oxygen species is endogenous antioxidants, which are found to be altered in asthma. A marked decrease in plasma antioxidant capacity occurs. Superoxide dismutase activity is higher in erythrocytes and serum of asthmatic than in normal subjects and is diminished in cells from lavage and brushing samples of patients with asthma. Higher level of erythrocyte catalase activity has only been found in Chinese asthmatic patients while decreased glutathione peroxidase activity has been well documented. Since there are considerable discrepancies in erythrocyte or plasma antioxidant enzyme activity in patients with asthma, the problem at this time is attempting to sort out these conflicting results and to find their roles in the pathogenesis of asthma. There is good evidence that antioxidant compounds may have a potential role in the treatment of asthma, especially of asthma exacerbation.

Response of blood cell antioxidant enzyme defences to antioxidant diet supplementation and to intense exercise

Exhaustive exercise induces oxidative stress. The cellular antioxidant defence systems have demonstrated great adaptation to chronic exercise. To establish the influence of the antioxidant diet supplementation on the erythrocyte and lymphocyte antioxidant enzyme activities in athletes at basal and post-exercise levels. Fifteen amateur trained male athletes were randomly distributed in two groups: control and antioxidant supplemented (90 days' diet supplementation with 500 mg/day vitamin E and 30 mg/day beta-carotene, and the last 15 days also with 1 g/day vitamin C). The study was double blind. Maximal and submaximal exercise tests were performed after three months of diet supplementation. The study was developed during the training and competition season. The sportsmen of the supplemented group presented significantly higher plasmatic final levels of vitamin C, vitamin E and beta-carotene. Erythrocyte glutathione reductase activity significantly decreased in the placebo group but was maintained in the supplemented group after the three months studied. The erythrocyte superoxide dismutase activity increased after the training/competition period in the placebo group. Lymphocyte catalase and glutathione peroxidase activities increased significantly in the supplemented group after the supplementation period but were maintained in the placebo group. No effects of the antioxidant supplementation were observed in the erythrocyte antioxidant enzyme response to the exercise tests. The antioxidant supplementation induced a better adaptation of lymphocyte catalase after submaximal test. Lymphocytes showed higher sensibility to antioxidant supplementation, improving the response of antioxidant enzymes to training and to acute exercise. In erythrocytes the training adaptations were more important than the antioxidant supplementation effects.

Increase in liver antioxidant enzyme activities in non‐alcoholic fatty liver disease

Steatosis may increase oxidative stress, which is counteracted by cellular enzymatic (cytosolic and mitochondrial superoxide dismutases (Cu/Zn-SOD and Mn-SOD), glutathione peroxidase (GPx), catalase) and non-enzymatic antioxidant systems. We aimed to determine, in patients with non-alcoholic fatty liver disease (NAFLD), the level of antioxidant defenses (1) in liver biopsies, to demonstrate the existence of oxidative stress; (2) in erythrocytes and plasma, to determine whether their antioxidant defenses reflect liver oxidative stress. Erythrocyte and plasma antioxidant defenses were prospectively studied in two groups of 16 patients: patients with NAFLD and controls. Liver biopsies were performed in eight NAFLD patients; liver antioxidant enzyme activities were measured and compared with those in 12 control livers used for transplantation. Cu/Zn-SOD, GPx and catalase activities were significantly higher in NAFLD livers than in controls whereas no significant differences were observed in Mn-SOD activity, and thiobarbituric acid-reactive substance (TBARS) concentration. No differences were observed in erythrocyte antioxidant enzyme activities (GPx, catalase, Cu/Zn-SOD), erythrocyte TBARS concentration, and plasma alpha-tocopherol concentration. Liver antioxidant enzyme activities were high in patients with NAFLD, reflecting an oxidative stress possibly involved in inflammation and fibrogenesis. However, erythrocyte and plasma antioxidant defenses did not reflect intrahepatic peroxidation.

Plasma total antioxidant capacity, lipid peroxidation, and erythrocyte antioxidant enzyme activities in patients with rheumatoid arthritis and osteoarthritis

Objectives: The metabolism of cells in inflammatory and noninflammatory arthritic joint diseases is subject to complex environmental controls. The aim of the present study was to investigate the total antioxidant capacity (TAC), levels of lipid peroxidation (LPO), and antioxidant enzyme activities in patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Design and methods: Plasma levels of TAC, malondialdehyde (MDA), the activities of some erythrocyte antioxidant enzymes, as well as erythrocyte sedimentation rates (ESR) were estimated in patients with RA and OA and compared with controls. Results: The plasma TAC levels were significantly lower in the RA group than the OA and control group ( P < 0.05). Plasma MDA concentrations were significantly higher in patients with RA than those with OA and healthy subjects ( P < 0.05). Erythrocyte GSH-Px and CAT activities were found to be significantly lower in patients with RA than those with OA and healthy subjects ( P < 0.05, P < 0.05, respectively). However, there were no significant differences in erythrocyte SOD activities between the groups ( P > 0.05). ESR were significantly higher in RA patients than in healthy subjects and patients with OA ( P < 0.01). Moreover, there were significant negative correlations between TAC vs. MDA, ESR vs. TAC, and a positive correlation between ESR vs. MDA in the RA group ( r = −0.398, P < 0.05; r = −0.422, P < 0.05; r = 0.530, P < 0.05, respectively). Conclusions: Our results demonstrated that levels of LPO are increased in patients with RA compared to patients with OA. In addition, plasma TAC levels are decreased in RA due to its inflammatory character. We conclude that detecting plasma TAC levels with this novel method may be used as a routine and rapid test to verify the levels of oxidative stress in RA. Furthermore, correlating TAC and LPO levels with acute phase reactants such as ESR may give some clues about disease activity in RA.

Effect of pentylenetetrazol-induced epileptic seizure on the antioxidant enzyme activities, glutathione and lipid peroxidation levels in rat erythrocytes and liver tissues

Objectives: In order to clarify whether oxidative stress accompanies epilepsy, we examined the effects of pentylenetetrazol (PTZ)-induced epilepsy on the lipid peroxidation and antioxidant enzyme activities in erythrocytes and liver tissues of adult Wistar rats. Materials and methods: The activities of antioxidative enzymes (glucose-6-phosphate dehydrogenase (G-6-PD)), copper, zinc-superoxide dismutase (Cu,Zn-SOD), catalase (CAT), selenium-dependent glutathione peroxidase (Se-GSH-Px) and the levels of reduced glutathione (GSH) and thiobarbituric acid-reactive substances (TBARS) were measured in erythrocytes and liver tissues of pentylenetetrazol (PTZ)-induced epileptic adult Wistar rats. Results: Single PTZ treatment in a convulsive dose of 50 mg/kg significantly reduced the erythrocyte Cu,Zn-SOD, CAT enzyme activities and GSH levels compared to controls ( P < 0.001, P < 0.001, P < 0.05, respectively). Erythrocyte and liver tissue TBARS levels in the epileptic group were significantly higher than controls ( P < 0.0001). There was a significant decrease in liver tissue Cu,Zn-SOD activity and GSH levels in the epileptic group ( P < 0.0001), whereas significantly higher activities of G-6-PD and Se-GSH-Px were found in the epileptic group. Conclusions: Our results demonstrate a generalized diminished antioxidant activity and increased TBARS level indicating enhanced oxidative stress in the liver and erythrocytes of epileptic rats. Increased oxidative stress in the liver of epileptic rats might be due to the activation of the recently found glutamate receptors in the liver. These findings suggest that the use of antioxidants with antiepileptic drugs and new drugs such as type-5 metabotropic glutamate receptor (mGlu5) antagonist (MPEP) might protect erythrocytes and liver tissue against anoxic damage and oxidative stress.

Preventive effect of vitamin E on iron-induced oxidative damage in rabbit

Although iron (Fe), plays an important role in different oxidative steps during the metabolism of the human body, it can cause free radical damage. Iron ions seem to play a major role in initiation and promotion reactions of intracellular lipid peroxidation. The aim of this study was to investigate if vitamin E has a protective effect on oxidative changes in erythrocytes induced by Fe treatment. Thirty male New Zealand white rabbits weighing 1400 +/- 50 g were used in the study. The animals were divided into three groups. The first group (n:10) was given 500 mg/kg iron-dextran through intraperitoneal (ip) injection. The second group was given 500 mg/kg iron-dextran+100 mg/kg vitamin E(ip). The third group constituted the control group and received a saline solution injection. The activities of erythrocyte antioxidant enzymes; Superoxide Dismutase (SOD), Glutatione peroxidase (GSH-Px), Catalase (CAT) and Malondialdehyde (MDA) level, an indicator of lipid peroxidation, were determined. Erythrocyte SOD, GSH-Px and CAT activities were decreased and MDA level was increased in iron-dextran treated animals compared to the control group (P < 0.05). The activities of the three antioxidant enzymes were increased and MDA level was decreased in iron-dextran and vitamin E treated group compared to the control group (P < 0.05). Our data indicate that lipid peroxidation occurs after iron overload in the blood. In the light of our findings, vitamin E administration can prevent the toxic oxidative effects induced by iron-dependent free radical damage in erythrocytes.

Superoxide anion radical, lipid peroxides and antioxidant status in the blood of patients with breast cancer

Background Reactive oxygen species (ROS), including superoxide anion radical (O 2 − ), plays an important role in carcinogenesis. The human body has developed different antioxidant systems to defend against free radical attacks. We investigated the changes of the antioxidant status in the blood of patients with breast cancer. Methods The O 2 − generation and the levels of malondialdehyde (MDA) were measured as an index of lipid peroxidation along with the examination of the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRx), the levels of reduced glutathione (GSH), oxidized glutathione (GSSG), and vitamins A, C, and E. Results The results showed that the levels of O 2 − and MDA, and the activities of antioxidant enzymes in the blood of the patients with breast cancer were significantly higher than the controls. However, the levels of vitamin C, GSH, GSSG and ratio of GSH/GSSG in the blood of the patients with breast cancer were significantly decreased compared to control subjects. Conclusions Oxidative stress may be involved in breast cancer. The increased activities of erythrocyte antioxidant enzymes may be a compensatory upregulation in response to the increased oxidative stress.