Hypoglycaemic activity and cardiac autonomic neuropathy amelioration of neem in alloxan-induced diabetic Wistar rats

Introduction: Diabetes-related complications encompass injury to blood vessels, renal system, integuments, feet and nerves resulting from hyperglycaemia. As herbal remedy, the effects of aqueous extract of Azadirachta indica (Neem) leaves on hyperglycaemia and Cardiac Autonomic Neuropathy (CAN) in rats were assessed. Methods: Thirty-five Wistar rats (both sexes) used in this study were assigned into two phases of three groups in each phase and a common control group; - Control (C), Diabetic group (DG), Glibenclamide group (AG), and Neem group (AN) with five rats in each group. All the groups in phase 1 except control were rendered diabetic by injection of 2% solution of alloxan monohydrate, intraperitoneally at 150 mg/kg. AG and AN rats were immediately given Glibenclamide (0.5mg/kg) and Neem extract (500mg/kg) respectively. The control group received 0.5ml of normal saline daily for 2 weeks. In phase 2, after injection of 2% alloxan monohydrate, rats were left till we confirmed that they were diabetic using glucometer before Neem and Glibenclamide were introduced to the corresponding groups. This was done at 48 hours when all rats were confirmed diabetic. At two weeks, Electrocardiography (ECG) was recorded. Results: There were signs of Cardiac Autonomic Neuropathy (CAN) in the DG groups during both phases such as increased heart rate, myocardial infarction, increased R and T amplitudes, Atrial fibrillation and flutter. Significance: It could be concluded that Neem reversed alloxan-induced hyperglycaemia but could not totally ameliorate the cardiovascular effects of CAN in diabetic rats once it is fully established.