Vitamin E improved redox homeostasis in heart and aorta of hypothyroid rats

Abstract

Objectives. Th e objective of this study was to evaluate the eff ect of Vitamin E on the oxidative stress parameters and antioxidant defense enzymes in the heart and aorta of 6-n-propylthiouracil (PTU)-induced hypothyroid rats. Methods. Th e animals were divided into 4 experimental groups: Group 1 (Euthyroid) received tap water, Group 2 (Hypothyroid) received 0.05 % of PTU in dissolved in their drinking water, Group 3 (PTU+Vit E) hypothyroid rats treated with Vitamin E, and Group 4 (Euthyroid+Vit E). Vitamin E was injected daily (20 mg/kg) to groups 3 and 4 via daily gavage for 6 weeks. Malondialdehyde (MDA) levels, total thiol levels, and the activities of Cu, Zn-superoxide dismutase (SOD) and catalase (CAT) were evaluated in the aortic and cardiac tissues. Results. A signifi cant decrease of thyroxine (T4) serum levels confi rmed hypothyroidism in rats, which received PTU. Th e MDA level increased and total thiol level decreased in the hypothyroid group compared to control group (p<0.001). Th e activities of SOD and CAT signifi cantly decreased in the hypothyroid rats in comparison to the control. Vitamin E treatment resulted in increased levels of total thiol, SOD, and CAT within aortic and cardiac tissues and decreased levels of MDA in comparison with the hypothyroid group (p<0.01-p<0.001). Conclusions. PTU-induced hypothyroidism resulted in oxidative stress. Chronic administration of Vitamin E to hypothyroid rats decreased the oxidative stress markers in the aortic and cardiac tissues.