Effect of 8 weeks of Endurance Training and Hydroalcoholic Extract of Olive Leaf on Coronary Vascular Bed Endothelial Disorder and Lipid Profile in Diabetic Male Rats

Background and purpose: Due to the high rate of diabetes in the community and the importance of herbal supplements and exercise in its treatment, the present study aimed at evaluating the effects of hydroalcoholic extract of olive leaf on coronary artery function in streptozotocin-induced diabetic male rats with and without exercise training. Materials and methods: In this experimental study, 50 male Wistar rats (250-300 g) were randomly divided into five groups (n=10 per group): 1. Healthy control (CO), 2. Diabetic control (DC), 3. Diabetic control + Exercise training (DC+EX), 4. Diabetic control + Olea europaea L. (D+OIL), 5. Diabetic + exercise training + Olea europaea L. (DC+EX+OIL). Diabetes was induced by intraperitoneal injection of nicotinamide-streptozotocin. The rats in D+OIL and DC+EX+OIL groups performed submaximal exercise on treadmill for 5 days a week/ 8 weeks and received 200 mg/kgbw Olea europaea L. extract by gavage at 8 AM daily for 8 weeks. Twenty-four hours after the last training session, Isolated hearts were perfused using the Langendorff method and hemodynamic parameters were assessed. Then, levels of antioxidant enzymes and lipoproteins in the blood were measured. Results: Olive leaf extract with 8 weeks of exercise training led to increased activity of superoxide- dismutase and catalaseenzymes and increased lipoprotein levels of LDL and HDL in diabetic rats but it had no effect on improving LDL levels. It also prevented increased response to coronary artery stenosis due to diabetes and increased response to coronary artery dilator. Conclusion: Current study could be helpful in increasing the tendency to use exercise and olive leaf extract in treatment of diabetic patients and preventing cardiovascular complications including coronary artery endothelial disorders in these patients.