Effect of photo-irradiated curcumin treatment against oxidative stress in streptozotocin-induced diabetic rats

Increasing evidence in both experimental and clinical studies suggests that oxidative stress plays a major role in the pathogenesis of diabetes mellitus. Although phenolic compounds attenuate oxidative stress-related damage, there are concerns over toxicity of synthetic phenolic antioxidants, and this has considerably stimulated interest in investigating the role of natural phenolics in medicinal application. In the present study, we examined the effect of photo-irradiated curcumin in experimental diabetes to evaluate the anti-hyperglycemic properties of this compound on streptozotocin (40 mg/kg of body weight)-induced diabetes. Photo-irradiated curcumin was given at a dose of 10 or 30 mg/kg of body weight. The level of blood glucose was elevated in diabetic animals. Circulatory lipid peroxidation, vitamin C, vitamin E, and enzymic antioxidants such as superoxide dismutase and catalase were analyzed. The antioxidant status decreased in diabetic animals. Oral administration of photo-irradiated curcumin for 45 days resulted in a significant decrease in the levels of blood glucose along with near-normalization of the enzymic activities and the levels of lipid peroxidative markers. The most effective results were obtained on treatment with 30 mg/kg of body weight of photo-irradiated curcumin.