Methods: Thirty-six Sprague-Dawley rats, weighing between 220 and 280 g, were included in this study and were randomly assigned to three groups with 12 rats in each group. While rats in the control group (Group 1) were fed standard rat chow diet, those in group 2 (High cholesterol diet group) and group 3 (100 mg/kg/day diosmin-hesperidin group) were fed high-cholesterol diet for three months. After the study period, the levels of total cholesterol, low-density lipoprotein (LDL) cholesterol, highdensity lipoprotein (HDL) cholesterol and triglycerides were measured in serum. Malondialdehyde (MDA), glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase levels were measured in serum and heart tissue samples.

Results: The levels of total cholesterol, LDL-cholesterol and triglyceride were not significantly different between the groups. High-density lipoprotein cholesterol level was found to be significantly higher in group 3 than that in groups 1 and 2. Malondialdehyde levels were not significantly different between the groups. Glutathione peroxidase and SOD levels were found to be significantly higher in group 3 than those in groups 1 and 2. There were no significant differences between the groups with respect to catalase levels. Intracardiac measurements of MDA, GPX, SOD and catalase were not found significantly different between the groups.

Conclusion: Diosmin-hesperidin administration to high-cholesterol diet-fed rats significantly increased HDL-cholesterol levels but did not significantly affect other lipid parameters. Positive changes occurred in oxidative-antioxidative balance and administration of diosmin-hesperidin significantly increased the levels of GPX and SOD.