Antioxidant Defense System In Erythrocytes Research Articles

Protective role of vitamins C and E in diclorvos-induced oxidative stress in human erythrocytes in vitro

Organophosphate (OP) pesticides such as dichlorvos (DDVP) intoxication has been shown to produce oxidative stress due to the generation of free radicals, which alter the antioxidant defense system in erythrocytes. In this study, the effects of DDVP (1, 10, 100 µM) or DDVP + vitamin C (VC; 10 µM) or vitamin E (VE; 30 µM), on the levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities in human erythrocytes were examined in vitro. There were no statistical differences between all groups for 1 µM concentration of DDVP. Treatment with DDVP alone produced an increase in the level of MDA and decreased activities of antioxidant enzymes (P < 0.05). Groups treated with vitamins and DDVP showed protective effects of vitamins against DDVP-induced changes in antioxidant enzyme activity and lipid peroxidation (LPO) (10 µM). At 100 µM concentration of DDVP vitamins had no effect on DDVP-induced toxicity. The results show that administration of DDVP resulted in the induction of erythrocyte LPO and alterations in antioxidant enzyme activities, suggesting that reactive oxygen species (ROS) may be involved in the toxic effects of DDVP. Also the data show that the plasma level of VC and VE may ameliorate OP-induced oxidative stress by decreasing LPO in erythrocytes at certain doses of OP pesicides.

Oxidative Stress and Oxidative Damage in Male Rat Erythrocytes Associated with Prolonged Exposure to Smoke Pollution

Exposure of animals to different duration of smoke can result in a wide range of adverse clinical conditions. Toxicological consequences arising from prolonged exposure may not be totally enumerated. The present study was to evaluate the oxidative stress-inducing potential of a short and long-time exposure of male rat erythrocytes to environmentally relevant to public health. Male Wistar rats were exposed to open municipal land-fill smoke for 30 and/or 60 days. The oxidative stress in erythrocytes was evaluated by assessing the magnitude of malondialdehyde production and reduced glutathione (GSH) contents and the activities of superoxide dismutase (SOD), catalase (C) and glutathione reductase (GR) after 30 and/or 60 days of exposure. After 30 days there was no change in SOD, catalase and GR activities and no alterations in GSH and lipid peroxidation (LPO). After 60 days, the levels and activities of SOD (23.62%), catalase (5.24%), GR (14.87%) decreased. Overall, the study demonstrates that the chronic exposure of male rats to smoke results in induction of oxidative stress and simultaneous reduction in antioxidative defense system in erythrocytes at 60 days of exposure.

Antioxidant and anti-atherogenic activities of three Piper species on atherogenic diet fed hamsters

Atherogenic diet is known to induce high plasma lipid concentration, oxidative stress and early atherosclerosis. Antioxidants have potentials to counter the effect of atherogenic diet. The present research aims at evaluating the antioxidant and anti-atherosclerotic activities of three Piper species (Piper guineense, Piper nigrum and Piper umbellatum) on atherogenic diet fed hamsters. Hamsters divided into 8 groups: normal control, atherosclerotic control and six test groups. The normal animals fed normal rodent chow, the atherosclerotic control animals fed the same rodent chow supplemented with 0.2% cholesterol and 10% coconut oil (high cholesterol diet). The 6 test groups' animals fed same diet as the atherosclerotic control group but with additional supplementation of 2 graded doses (1 and 0.25 mg/kg body weight, o.p.) of plant extracts for 12 weeks. The atherogenic diet induced a collapse of the erythrocyte antioxidant defense system (significant decrease in superoxide dismutase, catalase and glutathione peroxidase activities). Atherogenic diet also induced an increase in plasma total cholesterol, triglyceride, thiobarbituric acid reactive substances (TBARS), oxidation of low density lipoprotein cholesterol (LDL) and accumulation of foam cells in the aorta a hall mark for atherosclerosis. Administration of the Piper species prevented the collapse of the antioxidant system and the increase of plasma parameters maintaining them towards normality. The Piper species also prevented LDL oxidation by increasing the time (lag time) for its oxidation. The results suggest that these Piper species have significant antioxidant and anti-atherogenic effect against atherogenic diet intoxication.

Antioxidant and membrane-protective properties of an extract from the brown alga Laminaria japonica

This paper presents comparative data on the antioxidant and membrane-protective activities of an extract from the brown seaweed Laminaria japonica and the commercial drug Legalon. It was shown that intoxication with carbon tetrachloride was accompanied by the exhaustion of the antioxidant defense system of erythrocytes, an increase in their dimensional characteristics, and a change in the phospholipids to neutral lipids ratio. The Laminaria extract appeared to be more efficient than Legalon in the restoration of the lipid component of erythrocyte membranes and the removal of toxic stress.

갈대순분말이 고지방을 급여한 마우스의 지질대사 및 적혈구 항산화방어계에 미치는 영향

본 연구는 고지방을 급여한 마우스의 체내 지질개선 및 항산화 방어계에 미치는 갈대순의 영향을 구명하고자 하였다. 4주령의 ICR마우스(n=24)를 1주일간 적응시킨 후 정상식이를 급여한 정상군, 고지방을 급여한 고지방군, 고지방-갈대순분말 급여군으로 나누어 8주간 사육하였다. 갈대순분말은 사람이 하루에 3잔의 차를 마시는 양을 고려하여 식이에 1% 수준이 되도록 첨가?조제하여 급여하였다. 갈대순 분말군의 체중, 일일 식이섭취량과 에너지섭취량은 고지방군에 비하여 감소하는 경향이었다. 갈대순분말 급여 시 혈장의 총 콜레스테롤 함량은 고지방군에 비하여 19% 감소되었고 중성지질 함량은 36% 유의적인 감소를 보였다. 갈대순분말은 고지방식이로 축적된 간 조직의 중성지질 함량 변화에는 영향을 미치지 않았으나 콜레스테롤 함량은 고지방군에 비하여 유의적으로 낮추었다. 심장조직의 중성지질과 콜레스테롤 함량 역시 정상군에 비하여 고지방군이 각각 145%, 112%의 유의적인 증가를 나타내었으나 갈대순분말 급여로 중성지질 함량은 감소경향을 보였으며 콜레스테롤 함량은 정상군과 유사한 수준으로 개선되었다. 갈대순분말은 고지 방군에 비하여 분변으로의 중성지질과 콜레스테롤 배설을 각각 27%와 28% 유의적으로 증가시켰다. 갈대순분말은 간조직의 지방산 산화에는 영향을 미치지 않았고 지방산 합성 효소 활성을 유의적으로 억제하였다. 간 조직 중의 HMGCoA reductase와 ACAT 활성도 역시 갈대순급여군이 고지방군에 비하여 유의적으로 낮았다. 적혈구 중의 SOD와 CAT 활성은 정상군에 비하여 고지방식이 급여 시 유의적인 증가를 보였으나 GSH-Px 활성은 고지방식이로 인한 변화가 관찰되지 않았다. 반면, 갈대순분말 급여는 적혈구의 SOD와 CAT 활성과 지질과산화물 함량을 고지방군에 비하여 유의적으로 낮추었다. 이와 같이 갈대순분말은 고지방식 이를 급여한 마우스의 간 조직에서의 지방산과 콜레스테롤 합성을 저해하고 분변으로의 지질배설을 증가시킴으로써 혈장 지질개선에 효과적이었으며 적혈구의 항산화 효소활성도와 지질과산화물 함량도 개선하는 것으로 나타났다.

Changes in the Blood Antioxidant Defense Capacity During a 24 Hour Run

Changes in the Blood Antioxidant Defense Capacity During a 24 Hour Run The objective of this study was to determine whether running a 24-h race would cause oxidative damage and changes in the blood antioxidant defense capacity in endurance-trained athletes. Fourteen male amateur runners (mean age 43.0±10.8 y, body weight 64.3±7.2 kg height 171±5 cm, weekly covered distance 81±43 km, training history 8±9 y) who participated in a 24-hr ultra-marathon and volunteered to give blood samples during the race were enrolled for this study. Blood samples were taken before the run, after completing the marathon distance (42.217 km), after 12 h and at the conclusion of the race. The capacity of erythrocyte antioxidant defense system was evaluated by measuring the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), glutathione reductase (GR), concentrations of non-enzymatic antioxidants (uric acid and glutathione-GSH), and selected biomarkers of oxidative stress (i.e., plasma level of malondialdehyde (MDA) and plasma antioxidant capacity by FRAP ("ferric-reducing ability of plasma")). Moreover, in order to elucidate between-group differences in the total capacity of the blood antioxidant defense system, an index of antioxidant potential (POTAOX) was calculated as a sum of standardized values of activities of antioxidant enzymes (SOD, CAT, GPX, GR) and non-enzymatic antioxidants (uric acid, GSH). A progressive decline was observed in activities of SOD and CAT with the distance covered during the race, while the opposite trend was found in activities of GPX and GR that tended to increase. A significant decrease was recorded in GSH content after completing the marathon distance, which tended toward slightly higher values, without reaching the baseline level, at the finish of the race. Plasma concentration of uric acid (UA) was not significantly affected, except for the value recorded after 12 h of running that was significantly (p&lt;0.05) lower, while both markers of oxidative stress (FRAP and MDA) increased significantly after completing the marathon distance. Comparison of the calculated values of the POTAOX index recorded pre-race and throughout the competition implies that the most drastic decline in the total antioxidant capacity occurred at mid-race (i.e. after 12 h of running).

포도씨열수추출물이 고지방식이로 유도한 비만마우스의 지질대사와 적혈구 항산화 방어계에 미치는 영향

This study was investigate the effect of grape seed water extract (GSW) on lipid profiles, lipid metabolism and erythrocyte antioxidant defense system in high-fat diet-induced obese mice. Three groups of male C57BL/6 mice were fed different diets for 6 weeks: normal diet (Normal), high-fat diet (HF control; 37% calorie from fat) and high-fat diet supplemented with GSW (HF-GSW; 1% wt/wt). Supplementation of GSW did not affect the body weight, food intake, daily energy intake, white adipose tissue weights and plasma leptin level in high-fat fed mice. Plasma and hepatic cholesterol and triglyceride contents were significantly higher in the HF control group than in the Normal group; however, GSW supplement significantly lowered plasma triglyceride and hepatic cholesterol concentrations compared to the HF control group. GSW supplement significantly increased fecal excretion of triglyceride in high-fat fed mice. Hepatic carnitine palmitoyl transferase activity was significantly higher in the HF-GSW group than in the HF control group, while fatty acid -oxidation tended to be lowered by GSW supplement. Erythrocyte superoxide dismutase activity was also significantly higher in the HF-GSW group than in the HF control group and glutathione peroxidase activity tended to be lowered in HF-GSW group. The GSW supplement significantly lowered erythrocyte lipid peroxidation level compared to the HF control group. Accordingly, these results suggest that GSW can be considered as a lipid-lowering agent and as being effective for enhancing erythrocyte antioxidant defense system in high-fat diet-induced obese mice.

Oxidative stress and changes in antioxidative defense system in erythrocytes of preeclampsia in women

The present study was designed to investigate whether oxidative stress occurred to erythrocytes in preeclampsia and was related to disease. Indicative markers of oxidative stress and changes in antioxidant defense system were assayed in the erythrocytes of 22 healthy pregnant and 20 women with preeclampsia. Results of our work indicated high concentration of hydrogen peroxide, nitrite, peroxynitrite and lipid peroxides in preeclampsia compared to healthy pregnant women. Concentration of superoxide anion was lower in preeclamptic women. There were no differences in concentrations of vitamin E, reduced glutathione and oxidized glutathione. Activity of glutathione- S-transferase (GST) was higher while activities of superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) were lower in preeclamptic women. There were no differences in glutathione peroxidase (GSH-Px) activity between the two investigated groups. These results suggest that preeclampsia was characterized by oxidative stress and alteration of antioxidative defense system by disbalance in oxidative/antioxidative status of erythrocytes.

Effect of Selenium and α-Tocopherol on the Antioxidant Defense System of Goat Erythrocytes and the Hemic System

ABSTRACTThe effect of sodium selenite, α-tocopherol, and their combination was studied in the hemic system of goat. Incubation of goat blood with selenium and vitamin E for 24 h resulted in a decrease in hemoglobin concentrations in Se-and vitamin E-treated groups, whereas no change in the osmotic fragility was observed. In plasma the levels of albumin did not show any significant change in all the treatment groups. The acute phase protein (total protein) was found to be increased in the group treated with Se at a concentration of 10 μg, and ceruloplasmin in the plasma was significantly increased in the group supplemented with Se at a concentration of 20 μg. The catalase was found to be increased in both the Se treatment groups and the group that received vitamin E at a concentration of 10 μg. However, the effects on lipid peroxidation, acetylcholinesterase, and antioxidant enzymes such as superoxide dismutase are not significant. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) pattern of the proteins did not show any alteration. Also, no effect was observed in the membrane permeability and physicochemical alteration of erythrocytes in the presence of Se and vitamin E.

Induction of Oxidative Stress in Erythrocytes of Male Rats Subchronically Exposed to a Mixture of Eight Metals Found as Groundwater Contaminants in Different Parts of India

Exposure of animals and humans to different metal components through contaminated drinking water can result in a wide range of adverse clinical conditions. Toxicological consequences arising from the concurrent repeated exposure to multiple metal contaminants are not known. The purpose of the present study was to evaluate the oxidative stress-inducing potential of a mixture of eight metals (arsenic, cadmium, lead, mercury, chromium, nickel, manganese, iron), representative of groundwater contamination in different areas of India, in erythrocytes of male rats subchronically exposed to environmentally relevant doses via drinking water. The selection of these metals, as determined by literature survey of groundwater contamination in India, was primarily based on the frequency of their occurrence and contamination level above World Health Organization maximum permissible limit (MPL) in drinking water. Male albino Wistar rats were exposed to the metal mixture at 0, 1, 10, and 100 times the mode concentrations (the most frequently occurring concentration) of the individual metals in drinking water for 90 days. In addition, one group of rats was also exposed to the mixture at a concentration equal to the MPL of individual components. The oxidative stress in erythrocytes was evaluated by assessing the magnitude of malondialdehyde production and reduced glutathione (GSH) content and the activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glutathione reductase (GR) after 30, 60, and 90 days of exposure. MPL and 1x dose levels did not cause any changes. The mixture at 10x and 100x doses caused dose- and time-dependent effects. After 30 days, the 10x dose did not cause any changes except increase in SOD activity. The 100x dose increased the activities of SOD, catalase and GR and the GSH level, but caused no alterations in lipid peroxidation (LPO) and GPx activity. After 60 days, the 10x dose did not cause any changes. The 100x dose increased LPO and decreased all the antioxidant parameters, except GSH. After 90 days, both 10x and 100x levels elevated LPO. The 10x dose decreased GSH level and activities of SOD and catalase, but not of GPx and GR, whereas the 100x dose decreased all the antioxidative systems. Overall, the present study demonstrates that the subchronic exposure of male rats to the mixture of metals via drinking water results in induction of oxidative stress and concomitant reduction in antioxidative defense system in erythrocytes at 10 and 100 times the mode concentrations of the individual metals in contaminated groundwater.

Lambda-cyhalothrin-induced changes in oxidative stress biomarkers in rabbit erythrocytes and alleviation effect of some antioxidants

Erythrocytes are a convenient model to understand the membrane oxidative damage induced by various xenobiotic-prooxidants. This study was designed to investigate (1) the possibility of lambda-cyhalothrin (LC), a type II pyrethroid, to induce oxidative stress response in rabbit erythrocytes in vitro and its effect on selected antioxidant enzymes and (2) the role of vitamin C (VC; 20 mM) and vitamin E (VE; 2 mM) in alleviating the cytotoxic effects of LC. Erythrocytes were divided into three groups. The first group, previously prepared erythrocytes was incubated for 4 h at 37 °C with different concentrations (0, 0.1, 0.5, 1, 2.5, 5 mM) of LC. The second and third groups were preincubated with VC or VE, respectively for 20 min and followed by LC incubation for 4 h. Following in vitro exposure, LC caused a significant induction of oxidative damage in erythrocytes at different concentrations as evidenced by increased thiobarbituric acid reactive substances (TBARS) levels. However, a significant decrease in the content of sulfhydryl groups (SH-groups), and the activities of acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) were observed. The response was concentration dependent. VC or VE pretreated erythrocytes showed a significant protection against the cytotoxic effects induced by LC on the studied parameters. In conclusion, antioxidant vitamins especially VE could be able to ameliorate LC-induced oxidative stress by decreasing lipid peroxidation and altering antioxidant defense system in erythrocytes.

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.

Erythrocyte Antioxidant Defense System in Patients with Chronic Renal Failure According to the Hemodialysis Conditions

Patients suffering from chronic renal failure (CRF) are exposed to increased oxidative stress generated by uremic toxins, factors connected with hemodialysis, chronic inflammatory state, lack of vitamins A, E and selenium, advanced age, and parenteral iron administration. Their antioxidative system is inefficient. In erythrocytes, hexosemonophosphate (HMP) cycle does not assure an adequate amount of reductive equivalents (NADPH) necessary to restore reduced glutathione (GSH), an important free radical scavenger. Hemodialysis treatment also causes a large loss of glucose, which is the basic substrate for that metabolic pathway. The object of the research was to establish the influence of glucose present in dialysate on antioxidant defense system in red blood cells. A group of 51 patients undergoing regular hemodialysis using glucose (26 subjects, GL+ HD) or non-glucose fluid (25 subjects, GL- HD) was studied. The GSH concentration, glucose-6-phosphate dehydrogenase (G-6-P DH) and glutathione reductase (GSSG-R) activities were determined. Glucose concentration before and after the hemodialysis session was also measured. The activity of G-6-P DH was significantly higher in GL+ HD both before (p = 0.000) and after (p = 0.0002) the dialysis treatment compared to GL- HD, respectively, and to the healthy subjects (p = 0.000). The hemodialysis session caused a decrease in the activity of the enzyme in GL+ HD from 4.91 +/- 1.53 to 4.42 +/- 1.40 U/g Hb (p = 0.004) as well as in GL- HD from 3.97 +/- 1.00 to 3.59 +/- 0.87 U/g Hb (p = 0.007). The GSSG-R showed an increase in activity in CRF patients before HD (in GL+ HD to 2.57 +/- 0.76 and in GL- HD to 2.82 +/- 0.98 U/gHb). After dialysis, lower values were observed, particularly in GL+ HD (2.05 +/- 0.59 U/g Hb, p = 0.004). GSH concentrations in the examined group were higher (in GL+ HD 0.0205 +/- 0.008 and in GL- HD 0.0196 +/- 0.008 mmol/g Hb) than in controlled subjects (0.0142 +/- 0.002 mmol/g Hb) and decreased during dialysis treatment (considerably only in GL- HD to 0.0183 +/- 0.007 mmol/g Hb, p = 0.056). Glucose concentrations in GL+ HD were significantly higher compared to GL- HD (p < 0.002). Glucose presence in dialyzing fluid improves the HMP cycle activity as well as glutathione system reactions and determines a better antioxidant status of erythrocytes. It limits hemolysis and improves the hematological parameters in CRF.

The effects of charcoal-broiled meat consumption on antioxidant defense system of erythrocytes and antioxidant vitamins in plasma

With the aim of studying the effect of oral exposure to polycyclic aromatic hydrocarbons (PAH) on the antioxidant defence system of erythrocytes and antioxidant vitamins in plasma, the effect of consumption of charcoal-broiled beefburger was examined. PAH contents in charcoal-broiled beefburgers (CBB) prepared for study subjects were determined by HPLC. A total of 24 healthy men (mean age 21 years, range 20–22 years) were used in the present investigation. All were nonsmokers and had no occupational exposure to PAH. They volunteered to consume two CBB per day (mean weight of each, 70 g) at lunchtime over 28 consecutive days. Blood samples were collected from each subject 7, 14, 21, and 28 days before, during, and after the CBB consumption period. The hematological analysis for all subjects indicated that activities of antioxidant enzymes, glutathione peroxidase, superoxide dismutase, and catalase measured in the erythrocytes of all subjects were significantly lower during CBB consumption period compared with those of before CBB consumption period. Levels of thiobarbituric acid reactive substances in plasma were also higher significantly during CBB consumption period. All of the enzyme activities decreased to near baseline levels, before CBB consumption period, by 4 weeks after charcoal-broiled meat consumption ended; in contrast, however, levels of thiobarbituric acid reactive substances still increased. The same behavior was observed for the antioxidant vitamins measured in plasma including A, C, and E. All of these findings suggest that in studies of environmental and occupational exposure to PAH, the effects of dietary exposure should be taken into consideration.

Lipid peroxidation and resistance to oxidation in patients with type 2 diabetes mellitus.

We investigated lipid peroxidation, resistance of plasma and red blood cells to oxidation, and antioxidant defense system in erythrocytes and sera in patients with type 2 diabetes mellitus. One group included newly diagnosed 20 patients and the other included 20 patients treated with oral antidiabetic agents (OAD). Twenty healthy subjects served as controls. Serum and red blood cell malondialdehyde (MDA), glutathione (GSH), resistance to oxidation, and plasma thiol (total -SH) levels were measured. In addition, glycated hemoglobin, serum fructosamine, uric acid, total protein, total cholesterol, triglyceride and glucose levels were determined. Although newly diagnosed patients had higher serum and erythrocyte MDA levels than those of controls, the highest levels of MDA were determined in patients treated with OAD. MDA levels after exposing to oxidation increased in OAD group more than in newly diagnosed patients. Total -SH and erythrocyte GSH levels of the both diabetic groups were lower than controls. These results show that serum and erythrocyte lipid peroxidation was increased in diabetic patients. The sera of the patients showed a decreased resistance against oxidation. We therefore suggest that the effect of increased free radicals may be prevented by antioxidant systems in early stages of type 2 diabetes but in advanced stages this relationship is impaired owing to decreased antioxidant activity. Decreased red blood cell GSH and serum total -SH levels may be due to a compensation mechanism of the antioxidants.

Protective effect of vitamin E in dimethoate and malathion induced oxidative stress in rat erythrocytes

Organophosphate (OP) pesticides such as dimethoate and malathion intoxication has been shown to produce oxidative stress due to the generation of free radicals and alter the antioxidant defense system in erythrocytes. It is possible that vitamin E being present at the cell membrane site may prevent OP-induced oxidative damage. In the present study, rats were pretreated orally with vitamin E (250 mg/kg body wt, twice a week for 6 weeks) prior to oral administration of a single low dose of dimethoate and/or malathion (0.01% LD 50). The result showed that treatment with OP increased lipid peroxidation (LPO) in erythrocytes, however, vitamin E pretreated rats administered OP’s showed decreased LPO in erythrocytes. The increase in the activities of superoxide dismutase (SOD) and catalase (CAT) and total-SH content in erythrocytes from dimethoate and/or malathion treated rats as compared to control appears to be a response towards increased oxidative stress. Vitamin E pretreated animals administered OP’s showed a lowering in these parameters as compared to OP treated rats which indicates that vitamin E provide protection against OP-induced oxidative stress. The glutathione-S-transferase (GST) activity in erythrocytes was inhibited in OP intoxicated rats which partially recovered in vitamin E pretreated animals administered OP’s. Inhibition in erythrocyte and serum acetylcholinesterase (AChE) activity was not relieved in vitamin E pretreated rats administered OP’s probably due to the competitive nature of enzyme inhibition by OP’s. The results show that vitamin E may amelierate OP-induced oxidative stress by decreasing LPO and altering antioxidant defense system in erthrocytes.

Interaction of ascorbate and α-tocopherol enhances antioxidant reserve of erythrocytes during anemia in visceral leishmaniasis

Visceral leishmaniasis (V.L.) is associated with enhanced lipid peroxidation along with impaired function of antioxidant defense system in erythrocytes. The effect of chronic treatment with ascorbate and α-tocopherol was studied on erythrocytes in hamsters infected with Leishmania donovani. Combination treatment with both antioxidants proved to be a potential suppressor of lipid hydroperoxide formation as well as hypotonic osmotic lysis during the leishmanial infection. Positive correlations between the depleted levels of erythrocyte ascorbate, GSH and α-tocopherol exhibit proportionate alterations in the nonenzymatic antioxidant levels at different stages of infection. Indirect measurement of transmembrane electron transfer as ferricyanide reduction suggests an active participation of endogenous contents of ascorbate and α-tocopherol in the protection against oxidative damage of membrane lipids. Cooperative behavior of both antioxidants in the ferricyanide reducing capacity was further evinced by resealing the ghosts in presence of exogenous ascorbate and α-tocopherol. Furthermore, intravesicular ascorbate serves in the defense of extravesicular ferricyanide induced oxidation of endogenous α-tocopherol. The results suggest an interacting role of ascorbate and α-tocopherol in maintaining the antioxidant reserve of erythrocytes during anemia in V.L.

Antioxidant metabolism during blood storage and its relationship to posttransfusion red cell survival.

The status of the erythrocyte antioxidant defense system and its relationship to posttransfusion red cell survival were determined in erythrocytes stored for 35 or 42 days in CPD-A1 anticoagulant with a saline-adenine-glucose additive. As storage progressed, there was a significant increase in incubated Heinz body formation (P less than .001) and a significant decrease in reduced glutathione (GSH) stability (P less than .001). Stimulated pentose phosphate shunt activity also declined during storage (P less than .06), while unstimulated shunt activity remained unchanged. The increase in Heinz body formation was associated with decreased GSH stability (r = -.77, P less than .001), which in turn was associated with the decline in stimulated pentose shunt activity (r = .67, P less than .001). The changes in Heinz body formation (r = -.85), GSH stability (r = .83), and stimulated pentose shunt activity (r = .54) were all significantly (P less than .001) related to the decline in adenosine triphosphate (ATP) content of the erythrocyte. Red cell survival 24 hours after transfusion was significantly related to the GSH stability (r = .80, P less than .001) and to the ATP concentration (r = .76, P less than .005) on the day of transfusion. Thus, dysfunction of the erythrocyte antioxidant defense system occurs during blood storage and appears to be related, in part, to ATP depletion. The ability to maintain a normal reduced glutathione concentration during oxidant stress appears to be an important determinant of red cell survival in the peritransfusion period.