The Effect of 12 Weeks of Aerobic Exercise on Cardiac Antioxidant Enzymes in the Hypercholesterolemic Male Wistar Rats

Obesity has become a global problem today. Obesity can be caused by sedentary lifestyle and a high-cholesterol diet. This condition increases oxidative stress and decreases the activity of oxidative enzymes, resulting in many complications, including cardiovascular disorders. Aerobic exercise and avoidance of high-fat diets are used as a non-pharmacological intervention to increase antioxidant capacity; however, the exact mechanisms of this on the cardiovascular system have not yet been fully identified. The aim of this study was to evaluate the effect of 12 weeks of aerobic exercise on cardiac antioxidant enzymes in mice fed high cholesterol diet. Thirty-two laboratory Wistar rats (191.2 ± 19 g), age 6-8 weeks were randomly assigned to four groups after the hypercholesterolemia induction of half of the rats (adding 1% cholesterol to the food of the rats and sampling the tails of the rats). These four groups comprised of the aerobic exercise-normal nutrition group (n=8), hypercholesterolemic group (n=8), aerobic exercise- hypercholesterolemic group (n=8) and normal nutrition group (n=8). Each endurance exercise training session was held five days a week for 12 weeks. Twenty-four hours after the last training session, the rats were killed and the cardiomyocytes were removed. Moreover, the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) enzymes was evaluated by specific kits. The results showed that increasing blood cholesterol had a statistically significant effect on reducing SOD, CAT, and GPX in heart tissue (p=0.001). Furthermore, it was found that aerobic exercise significantly increases the activity of antioxidant enzymes in cardiomyocytes (p=0.001). The highest decrease in the level of antioxidant enzymes was related to the hypercholesterolemic group and the highest increase was related to the aerobic exercise-normal nutrition group. Cholesterol-rich diets reduce the activity of antioxidants in the heart. Although aerobic exercise increases the heart’s antioxidant activity, it seems that avoiding a high-cholesterol diet can play a more effective role.