RÉSUMÉ
To find out the mechanism of action of Azadirachta indica aqueous leaf extract (ALE) as hypoglycaemic agent. Materials and Methods: Overnight fasted albino rats of Wister strain of either sex were divided into 3 groups-a) Control (5% aqueous gum acacia suspension 5ml/kg, PO), b) Test (ALE-500mg/kg, PO) and c) Standard (glibenclamide 0.5mg/kg, PO). Blood glucose was estimated before administration of drugs and at 30min, 60min & 120min after the administration of drugs. For glycogen estimation also different animals were taken and divided into similar groups and after 1h of administration of drugs, the animals were killed and glycogen concentration from the liver, skeletal muscle and cardiac muscle were estimated. Results: The ALE produces a marked decrease in blood glucose level in normal rats. The glycogen content of liver, skeletal muscle and cardiac muscle was increased significantly (p<0.001) after 1h of administration of ALE as compare to control. Conclusion: ALE decreases blood glucose level and increases glycogen concentration in liver, skeletal muscle and cardiac muscle significantly. Increased glycogen synthesis is one of the important mechanisms responsible for its hypoglycemic action.