Antidiabetic and Antioxidant Activities of Zizyphus lotus L Aqueous Extracts in Wistar Rats

Objectives: Zizyphus lotus L. is a medicinal plant, used in traditional medicine for its multiple therapeutic properties. The aim of the present study was to determine the antidiabetic and antioxidant effects of aqueous extracts of different parts of Zizyphus lotus in diabetic Wistar rats. Research methods and procedures: The male Wistar rats were rendered diabetic by intraperitoneal (i.p.) injection of streptozotocin (40 mg/kg body weight). Aqueous extracts from different parts, i.e, root, leaf, and seed of Zizyphus lotus L. were prepared and administrated orally to the animals at the dose of 300 mg/kg for 21 days. Blood glucose level was measured, and antioxidant status was assessed by determining oxygen radical absorbance capacity (ORAC) and the activities of enzymes like catalase, glutathione reductase and peroxidase in pancreas, liver, and erythrocytes. Vitamin C levels were determined by precipitating with 10% trichloroacetic acid. Vitamins A and E concentrations were measured by HPLC. Results: The leaf and root, but not seed, extracts exerted the glucose lowering effect on 21st day of postadministration. The leaf and root extracts corrected antioxidant status of diabetic animals in pancreas, liver and erythrocytes. The concentrations of different vitamins (vitamin A, C and E) in diabetic rats were also modulated by leaf and root, but not seed, extracts. Conclusion(s): Our study shows that oral administration of Zizyphus lotus L. extracts from roots and leaves exerted antidiabetic and antioxidant effects in diabetic rats. Z. lotus L. seems to be a good candidate to lower, in addition to conventional antidiabetic drugs, the hyperglycaemia in diabetic subjects.