Protective Effect of White-Skinned Sweet Potato (Ipomoea batatas L.) against Renal Damage in Streptozotocin-Induced Diabetic Rats

Abstract

White-skinned sweet potato (Ipomoea batatas L.) has been traditionally used for diabetes treatment and management in many countries. In this experiment, methanol extract of white-skinned sweet potato (WSPMe) at a dose of 100 or 200 mg/kg body weight was tested to evaluate its effect on renal damage in streptozotocin (STZ)-induced diabetic rats. Its efficacy was compared with that of insulin secre-togogue, glimepiride (50 μg/kg body weight). Experimental diabetes was induced by a single dose of STZ (45 mg/kg, i.p.) injection. The WSPMe and glimepiride were administered orally for 14 days and the effects on glucose, renal markers including blood urea nitrogen (BUN), creatinine and lactate dehydrogenase (LDH), lipid peroxide (LPO) level, antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathion-S-transferase (GST) activities in kidney were studied. An increase in BUN, creatinine, LDH, glucose, LPO levels and decrease in SOD, CAT, GPx and GST features were observed in diabetic control rats. Administration of WSPMe at a dose of 200 mg/kg body weight caused a significant improvement in blood glucose, LPO level, renal markers, lipid peroxidation markers and increased antioxidant levels in diabetic kidney. In conclusion, the WSPMe was found to be effective in reducing oxidative stress, thus confirming the ethnopharmacological use of I. batatas L. in protecting diabetes and its complications.