Effect of Ethanolic leaf extract of Elaeocarpus tectorius (Lour.) Poir. on Retinal Oxidative Stress in Streptozotocin-nicotinamide Induced Diabetic rats

Abstract

Oxidative stress plays a crucial role in the pathogenesis of diabetic retinopathy and causes loss of vision. Elaeocarpus tectorius (Lour.) Poir. is a tree species that bears edible fruits and is traditionally used to treat diabetes. The study is aimed to investigate the ameliorative effect of ethanolic leaf extract of E. tectorius on retinal oxidative stress and aldose reductase levels in STZ-NIC-induced diabetic rats. The leaf extract was orally administered to diabetic rats once a day for about 28 days at doses of 200 and 400 mg/kg b.w. Fasting blood glucose levels were determined at regular intervals during the treatment period and retinal superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, lipid peroxidation levels and aldose reductase activity were assessed at the end of the experiment. Oral administration of E. tectorius leaf extract caused a significant decrease in the fasting blood glucose levels of diabetic rats. The extract also improved the retinal antioxidant status by increasing the levels of superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione. The rate of lipid peroxidation was lowered in diabetic rats as a result of treatment with the leaf extract. The diabetic rats treated with the leaf extracts also had lower retinal aldose reductase activity when compared to the untreated diabetic rats. This study suggests that Elaeocarpus tectorius leaf extracts exhibit protective effects and improve the antioxidant status of the retina under diabetic conditions helping in the prevention and management of diabetic retinopathy.