Background and Objective: Previous studies have distinctly illustrated the decreasing effects of lemon and garlic extracts on blood glucose and cholesterol. In the present study, the anti-diabetic, anti-atherosclerotic and antioxidant effects of combined lemon and garlic extract were evaluated in diabetic rats fed with high cholesterol diet.

Materials and Methods: The experiment was performed in five groups of rats (N=40); control, diabetic, diabetic plus high-cholesterol, diabetic plus extract and diabetic plus high-cholesterol plus extract. Diabetes was induced by an intravenous injection of streptozotocin (37mg/kg). High-cholesterol diet was prepared by adding 4% cholesterol and 1% colic acid to standard food. Treated groups received lemon and garlic extract orally (1ml, twice a day) for 60 days. At the end, the heart malondialdehyde (MDA) and histopathological changes of aorta were assessed.

Results: Blood glucose significantly increased in diabetic groups (>200mg/dl) and blood cholesterol significantly increased in diabetic plus high-cholesterol rats (187±15mg/dl). Combined extract significantly decreased the blood glucose of diabetic plus extract group (147±7mg/dl) compared to diabetic group (P<0.05). Also, this extract meaningfully decreased the blood cholesterol of diabetic plus high-cholesterol plus extract group (102±10mg/dl) compared to diabetic plus high-cholesterol group (P<0.05). The MDA content of the heart were high in diabetic and diabetic plus high-cholesterol groups plus combined extract decreased the level of MDA in both treated groups. Finally, damage to aorta and atherosclerosis was only observed in diabetic& high- cholesterol group.

Conclusion: Based on our findings, combined extract of lemon and garlic was able to prevent atherosclerosis formation and damage of aorta probably by reduction of tissue oxidative stress, blood glucose and cholesterol in diabetic rats fed with high cholesterol diet.