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Abstract Background and objective: Exposure of red blood cells to oxygen radicals can induce Lipid proxidation, hemoglobin damage and hemolysis of erythrocyte .The present study was designed to determine the alteration of plasma lipid peroxidation and erythrocyte Superoxide Dismutase and Glutathione Peroxidase enzyme activities in stored blood and to find out the quantitative alterations and the useful length of stored blood. Materials and Methods: First, the whole blood form 10 donors was taken. Then Red Blood Cells(RBC) were counted, the levels of Potassium(P) and lactate dehydrogenate activity(LDH) were measured to determine the amount of hemolysis, the plasma levels of malondialdehyde (MDA), erythrocyte Superoxide Dismutase(SOD) and Glutathione Peroxidase(GPx) were studied for determination of lipid peroxidation and antioxidant enzyme activities at the days of 0,1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33 and 35 of the storage. Results: upon storage time, the plasma levels of malondialdehyde (MDA) and Potassium and lactate dehydrogenate activity increased (P< 0.05) whereas erythrocyte Superoxide Dismutase and Glutathione Peroxidase enzyme activities and Red Blood Cells decreased (P< 0.05). The alterations of MDA, SOD, GPx, P, LDH and RBC in the measurement days were as follows: MDA, P and LDH significantly increased at the day of 9, 5 and 5 whereas SOD,
GPx and RBC decreased at the day of 11, 7 and 29 respectively. Conclusion: The results of this study showed that the increased level of MDA and decreased SOD and GPx in stored blood can cause the beginning of hemolysis of erythrocyte therefore, it is necessary to control these factors before storing the donated blood. Keywords: lipid peroxidation, Superoxide Dismutase, Glutathione Peroxidase

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Abstract Background and Objective: Flavonoids play an important role in non-enzymatic reaction against oxidative stress. These are polyphenolic compounds in tea structure that could be reacted with free radicals and neutralized them. In this study, we investigated the anti-oxidant impact of Camellia Sinesis on the liver of thioacetamide -injected male albino mice. Material and Methods: In this study, 40 male mice were categorized in five groups of eight. The first group was control. The second and the third group received 100mg/kg and 150mg/kg of thioacetamide, respectively. The fourth group received 100mg/kg thioacetamide followed by black tea (5 gr/100) and the fifth one received 150mg/kg thioacetamide followed by black tea (5 gr/100). Tioacetamide was given via intraperitoneal. After that, for 30 days, they were only fed on black tea (5 gr/100). At the end, catalase (CAT) and glutathione peroxidase (GPx) activity were measured. Results: Based on the results, catalase(CAT) and glutathione peroxidase(GPx) activity were significantly increased in the groups of Thioacetamide and black tea compared to those of only Thioacetamide groups (p<0.05). Conclusion: The increase of these enzymes in tea groups shows the anti-oxidant effect of black tea that can be caused by Catechin. Keywords: Antioxidant Thioacetamide Black Tea Glutathione Peroxidase Catalase

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Background and objectives: Endurance exercise causes fatigue due to mitochondrial dysfunction and oxidative stress. The present study was designed to investigate the effects of taurine supplementation on lipids peroxidation and antioxidant activity during endurance activities. 
Methods: Twenty-four male volunteers aged 27 ± 1.8 years and weighting 74.9 ± 5.9 kg were randomly divided into three groups: taurine supplementation (n=8), placebo (n=8), and control (n=8). The subjects completed a 28-day endurance training protocol. Biochemical parameters such as superoxide dismutase (SOD), glutathione peroxidase (GPX) activities, as well as malondialdehyde (MDA) concentrations (8 hours before the first session and 8 hours after the last session) and maximum rate of oxygen consumption, were measured to evaluate the antioxidant, lipid peroxidation, and VO₂ max status respectively. Finally, data were analyzed by SPSS software at a significance level of <0.05.
Results: Taurine supplementation significantly increased SOD (p=0.001) and GPX (p=0.001) but significantly decreased MDA (p=0.001). However, it had no significant effect on the VO₂ max. 
Conclusion: The results of the present study indicate that taurine has antioxidant effects against endurance exercise-induced oxidant stress and lipid peroxidation.