The effect of endurance training and zinc supplementation on glutathione peroxidase activity and total antioxidant capacity of skeletal muscle of male wistar rats

Considering the role of zinc in activating antioxidant enzymes, the aim of the present study was to investigate the effect of eight weeks of endurance training and zinc supplementation on glutathione peroxidase activity and total antioxidant capacity in the skeletal muscle of male Wistar rats.

Thirty two mature male Wistar rats, were randomly divided into four groups (each group was included eight rats) as control, endurance training, zinc supplementation and endurance training+supplement. The training protocol consisted of running on a treadmill for eight weeks (five days/week) with ad libitum access to water and food. In the zinc supplemented and endurance training+zinc groups, 227 mg of zinc sulfate were used per 100 ml of consumed water for eight weeks period. Then, 48 hours after the last exercise session and after eight hours of fasting, tissue samples of gastrocnemius muscle were collected and enzyme activity of glutathione peroxidase (GPX) and total antioxidant capacity (TAC) in gastrocnemius muscle was measured by spectrophotometric method. Data were analyzed using one-way analysis of variance and Tukey’s post hoc tests at the significant level p≤0.05.

The results showed that after eight weeks of endurance training along with zinc supplementation there was a significant increase in GPX of gastrocnemius muscle compared to the endurance training group (p=0.001). In addition, eight weeks of endurance training showed a significant decrease in GPX of gastrocnemius muscle compared to the control group (p=0.03). Moreover, endurance training along with zinc supplementation also showed a significant increase in TAC of gastrocnemius muscle as compared to supplement (p=0.008) and training (p=0.001) groups.

Considering the effect of zinc supplementation along with endurance training on increasing of GPX and TAC, zinc supplementation will probably prevent the reduction of antioxidant enzymes and complications caused by strenuous endurance training.