Effect of Allium porrum L. on insulin release from pancreatic beta cells in streptozotocin-induced diabetic rats

Allium porrum L. (Leek) has been widely used in Persian foods as a flavor component and in Iranian folk medicine for treatment of gastrointestinal and infectious complaints. In the present study, effect of hydro-ethanol extract of the leaves was investigated for releasing insulin from the pancreatic beta cells in streptozotocin-induced diabetic rats. Rats were injected (i.p.) with streptozotocin 70 mg/kg. The hydroethanolic extract was administered at doses 50, 100, 150 and 200 mg/kg for 16 days, intraperitoneally. After administration period, the animals were anaesthetized by diethyl ether. Blood samples were drawn from the heart. Serum glucose levels were determined by the glucose oxidase method. To determine the insulin releasing activity, the pancreas was excised, fixed in 10 percent formaldehyde and embedded in paraffin for sectioning. Pancreatic sections of 5 micron were processed for examination of insulin-releasing activity using an immunocytochemistry kit. The results showed that administration of the hydroethanolic extract exhibited a significant reduction in serum glucose. Administration of streptozotocin decreased the number of active Langerhan’s islet in comparison with normal rats. Treatment with the Allium porrum leaves extract increased significantly the active Langerhan’s islet in comparison with the diabetic control rats. So, the plant has hypoglycaemic effect by increase insulin secretion.