Cardioprotective potential of melatonin, quercetin and resveratrol in an experimental model of diabetes.

Oxygen radicals participate in the pathogenesis of heart damage. Diabetes accelerates the formation of reactive oxygen species (ROS). We investigated the effects of the antioxidants, melatonin, quercetin and resveratrol, on cardiomyopathy and apoptosis in rats with streptozotocin (STZ) induced diabetes mellitus (DM). Rats were divided into five groups of seven: control, DM, DM + melatonin, DM + quercetin and DM + resveratrol. All treatments were begun with a single dose of STZ to induce diabetes and experimental treatments were continued daily for 30 days. Morphologic and apoptotic changes were analyzed by histological assessment. The heart tissue of the control group exhibited normal histology, whereas the heart tissue of the DM group exhibited vacuolization, necrosis, congestion, infiltration and myofibril loss. The DM group exhibited significantly increased apoptosis compared to the control group. Differences in anti-apoptotic effects were statistically significant for all three antioxidant treatment groups; the anti-apoptotic effects of quercetin and resveratrol were similar. Melatonin, resveratrol and quercetin exhibited protective effects against diabetic heart damage.