Effect of Exercise on Blood Antioxidant Status and Erythrocyte Lipid Peroxidation: Role of Dietary Supplementation of Vitamin E

We tested the effects of moderate physical exercise on the blood antioxidant capacity and erythrocyte lipid peroxidation in 21 Wistar albino rats. Erythrocyte superoxide dismutase (SOD) activity increased significantly (p<0.05) in control exercised animals (C-Ex), but catalase activity did not change. SOD activity was decreased by dietary supplementation of vitamin E (p<0.05). In vitamin E supplemented group (E-Ex), catalase activity was reduced in comparision to C-Ex group. Total glutathione (total GSH) level was unaffected by the exercise. However, significant reduction was observed in reduced glutathione (GSH), whereas oxidized glutathione (GSSG) increased (p<0.01 and p<0.001, respectively). In E-Ex animals, total GSH and GSH were increased in comparison to C-Ex group. GSH/GSSG ratio decreased abnormally in both exercised groups (p<0.001). Serum cholesterol and uric acid levels increased significantly after exercise (p<0.05). The susceptibility of eryhrocytes to in vitro peroxidation increased in C-Ex and EEx animals (p<0.001 and p<0.01, respectively). Elevated malondialdehyde (MDA) concentrtaion in serum attained statistical significance after exercise. However, this elevation was prevented by vitamin E supplementation. Our results indicated that moderate intensive treadmill running exercise was sufficient to result in muscle damage and increases in the susceptibility of erythrocytes to in vitro peroxidation. In addition, dietary supplementation of vitamin E is able to minimize oxidative damage caused by exercise.