Hypoglycemic effect of extract of Juglans regia L. leaves on alloxan-induced diabetic rats

Diabetes is a metabolic disorder characterized by hyperglycemia resulting from defects in insulin secretion, insulin action or both. Juglans regia L. (Juglandaceae) has been used in Iranian traditional medicine in diabetes treatment. In this study the blood glucose and lowering effects of hydroalcoholic extract of walnut leaves have been investigated in Wistar rats. In this research 18 white male rats, with 180-220 g weight were randomly allocated into three groups with six rats each group: group 1)nondiabetic control (group 2) diabetic control (group 3)diabetic rats treated with hydro-alcoholic extract of walnut leaves (200 mgkg-1 BW). Before the blood sampling, rats had been fasted for 16h, and then fasting blood samples were collected in tubes with heparin. Sampling was performed from the orbital sinus for estimation of blood glucose and others factors. After the blood sampling at the end of experimental period, pancreatic tissue removed from rat body. Then some sections were made and size of islets was investigated. The results indicated significant reduction in serum glucose and glycosylated haemoglobin levels in the third group (P<0.05). Histomorphological investigation of pancreatic islets showed that the size of pancreatic islets is different among the experimental groups. The average of pancreatic islets size indicated significant reduction in diabetic group compared to other groups (P<0.05). This research showed that using walnut extract could be effective on regeneration of injured pancreatic islets in diabetic rats. Probably this effect related to antioxidant compounds in extract. It seems that increase in islet size is the result of remainder cells proliferation.