Evaluation of hypoglycemic activity of opuntia dillenii haw fruit juice in streptozotocin-induced diabetic rats

ABSTRACT

Opuntia dillenii Haw fruit is used in folk medicine as an antidiabetic agent. The aim of this study was to evaluate the possible curative role of O. dillenii fruit juice using the streptozotocin [STZ]-induced diabetic rats. The nutritive value of the edible portion of the fruit was also assessed. The results showed that O. dillenii fruit is a rich source of fiber, carbohydrates, vitamins B[1], B[2] and C, in addition to the minerals, Fe, Zn, Cu, Cr, Mn; Ca, and Mg. Biological results showed that intraperitoneal injection with STZ caused highly significant reduction in body weight gain%, highly significant elevation in blood glucose concentration accompanied by significant reduction in liver glycogen cotent as compared with control group. Diabetic rats also revealed significant elevation in lipid peroxide [MDA] level, highly significant elevation in total cholesterol [TC], triacylglycerols [TAG], low-density lipoprotein cholesterol [LDL-C] and very low-density lipoprotein cholesterol [VLDL-C] concurrent with highly significant reduction in high-density lipoprotein cholesterol [HDL-C] as compared with control group. Oral administration of O. dillenii juice had no effect on normal rats. Meanwhile, oral administration of O. dillenii juice to diabetic rats induced siginficant improvement in body weight gain% and lipid profile, it reduced significantly blood glucose and MDA levels as compared with non treated diabetic group. Histopathological investigation of the pancreatic tissue of STZ-diabetic rats represented the presence of necrosis, edema and congested blood vessels in the islets of Langerhans cells. O. dillenii fruit juice treatment overcome the previous changes, the majority of the cells tend to be normal.The improvement in the cells of Langerhans islets may explain the antidiabetic effect of the fruit juice under study/It also may improve the insulin receptors of beta-cells. It could be concluded that O. dillenii fruit juice had a potent hypoglycemic activity, this effect may be attributed to its antioxidant activity and its high content of chromium which was proved in this study. Therefore, it could be recommended that O. dillenii should be ingested as fresh fruit to diabetic and hypercholesterolemic patients beside the usual therapy