Effects of Crude Extract of Neem Bark on the Pancreas of Streptozotocin Induced Diabetic Wistar Rats

This study investigated the histological and serum enzymatic activities of Azadirachta indica, an Indian medicinal plant, on the pancreas in streptozotocin induced diabetic adult wstar rats.

Forty six adult wistar rats weighing 100 g to 220 g were randomly separated into four groups; Group A was regarded as the control , while group B was the diabetic group, C and diabetic – extract treated group. The control group received distilled water throughout the experiment; the remaining three groups were induced with streptozotocin intra-peritoneally to induced diabetes in the wistar rats. After some days, the animals were confirmed diabetic with the help of a measuring glucometer. Thereafter, group B diabetic rats remained untreated while Group C and D were treated with a low dose (250 mg/kg) of the crude neem bark extract and a high dose (500 mg/kg) of the extract respectively for 42 days. The aqueous neem bark extract was suspended in the drinking water of the treated animals for the period of 42 days. The body weights of the animals were weighed weekly and likewise the measurement of the blood glucose level was taken. The animals were sacrificed at the end of 42 days by cervical dislocation and the pancreas was removed and weighed immediately using sensitive weighing balance. The blood samples were collected from the sacrificed animals into EDTA bottle for serum enzymatic analysis. The organ pancreas was fixed in a 10% formol saline, processed and stained with Heamatoxylin and Eosin for general histological study.

The microscopic examination of diabetic group showed some degenerative and necrotic cells which made the pancreatic tissue distorted compared with the control that appeared normal. The diabetic group C and D rats treated with the extract showed ameliorative potentials of the extract with improvement in histo-architecture of the pancreatic tissue following recovery from damage. Analysis of the blood serum level showed that the aqueous neem bark extract has ameliorative effect on the enzymatic activities in serum of the treated rats. The alanine amino transferase, aspartate amino transferase and alkaline phosphatase levels were significantly reduced (P<0.05) in the crude extract- treated animals compared with the untreated group B and control group A with significantly increased ( P<0.05 ) enzymatic activities in wistar rats in these groups. The antioxidant status was compromised in diabetic group B with significantly increased (P<0.05) LPO, reduced SOD and GSH compared with significantly reduced (P<0.05) LPO, increased (P<0.05) SOD and GSH in group A- control and Group C and D diabetic-extract treated Wistar rats.

Similarly, the blood glucose level increased significantly (P<0.05) in group B diabetic group compared with significantly reduced (P<0.05) blood glucose level in group A control as well as C and D extract-treated rats. The study concluded that crude extract of neem has ameliorative potentials on streptozotocin-induced diabetic wistar rats characterized by oxidative damage which reveals improvement in tissue morphology.