Protective effect of crocin and voluntary exercise against oxidative stress in the heart of high-fat diet-induced type 2 diabetic rats

Background: Oxidative stress plays a critical role in the pathogenesis and progression of type 2 diabetes and diabetic-associated cardiovascular complications. This study investigated the impact of crocin combined with voluntary exercise on heart oxidative stress indicator in high-fat diet-induced type 2 diabetic rats. Materials and methods: Rats were divided into four groups: diabetes, diabetic-crocin, diabetic-voluntary exercise, diabetic-crocin-voluntary exercise. Type 2 diabetes was induced by high-fat diet (4 weeks) and injection of streptozotocin (intraperitoneally, 35 mg/kg). Animals received crocin orally (50 mg/kg); voluntary exercise was performed alone or combined with crocin treatment for 8 weeks. Finally, malondialdehyde (MDA), activity of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were measured spectrophotometrically. Results: Treatment of diabetic rats with crocin and exercise significantly decreased the levels of MDA (p < 0.001) and increased the activity of SOD, GPx, and CAT compared with the untreated diabetic group. In addition, combination of exercise and crocin amplified their effect on antioxidant levels in the heart tissue of type 2 diabetic rats. Conclusion: We suggest that a combination of crocin with voluntary exercise treatment may cause more beneficial effects in antioxidant defense system of heart tissues than the use of crocin or voluntary exercise alone.