ABSTRACT:
Recently, polyphenols have gained more attention, owing to their antioxidant capacity. Theobroma cocoa is rich in polyphenols particularly in catechins and procyanidins. The antioxidative, metal chelating and free radial scavenging property of polyphenols can benefit humans in health and diseases. Nephrotoxicity is the major cause of morbidity and mortality in diabetes mellitus and it is the leading cause of end stage renal disease. Hyperglycemia induced oxygen free radicals acts as mediator in worsening the diabetic complications as it leads to oxidative stress and subsequent oxidative damages, leading cell and tissue injury. Hence it was proposed to evaluate the antioxidant activity of methanolic extract of Theobroma cocoa in long-term diabetic complications such as diabetic nephrotoxicity. Sprague-Dawley rats of both sexes were divided into 4 groups, Control, Diabetic control, Diabetic + methanolic extract of Theobroma cocoa, and Diabetic + Vit E group. Blood urea, serum creatinine and serum uric acid as well as plasma malondialdehyde, superoxide dismutase, catalase, reduced glutathione were estimated and histopathological studies of kidneys were performed. Alloxan at the dose of 120mg/kg i.p, for 2 months at the interval of 14 days, induced diabetes. This prolonged diabetes increased oxidative stress and caused an increase in the levels of serum creatinine, urea, uric acid and plasma malondialdehyde while there were decrease in the levels of superoxide dismutase, catalase and reduced glutathione in diabetic group as compared to normal control group. Histopathological examination also revealed hemorrhage, necrosis, and infiltration of leukocytes around the glomerulus and interstitial spaces. Co-administration of methanolic extract of Theobroma cocoa orally, daily for 2 months in diabetic-induced rats caused decreased in the levels of serum creatinine, urea, uric acid and plasma malondialdehyde. Increased levels of superoxide dismutase, catalase and reduced glutathione were also found, indicating significant changes in oxidative parameters as well as kidney function tests. Thus the study revealed protective antioxidant free radical scavenging activity of Theobroma cocoa in diabetic nephrotoxicity.