ABSTRACT
This study investigated the effects of Azadiracta Indica seed extract on blood glucose levels of streptozocin-induced diabetic and normoglycemic Wistar rats. An acute toxicity studies of the extract Azadiracta Indica was done, the result of the acute toxicity study showed that the extract had an LD50 3000mg/kg bodyweight via intraperitoneal route in Wistar rats. A preliminary phytochemical screening was done which revealed the presence of flavonoids tannins, glycerin, cholesterol, steroids alkaloids saponin, triterpenoid and reducing sugar. After which the three doses (500mg/kg, 1000mg/kg and 1500mg/kg bodyweight) of the extract were administered to streptozocin-induced diabetic and normoglycemic Wistar rats. The effects of the extract on blood glucose levels of the animal were compared with untreated control and Biphasic Isophane Insulin treated groups. In the streptozocin-induced diabetic groups, there was no significant change in the blood glucose levels after 1 hour of extract treatment in all the groups given different doses. After 3 hours there was a significant decrease (P<0.05) in the group when given 1000mg/kg bodyweight of the extract compared to the untreated control. After 5 and 7 hours there was a significant decrease (P<0.05) in the groups given 500 and 1000mg/kg bodyweight of extract when compared to untreated control. However after 1 and 3 hours there was no significant change in the blood glucose levels when compared to the insulin- treated group. After 5 and 7 hours there was only significant increase (P<0.05) in the group given 1500mg/kg bodyweight of the extract when compared to insulin- treated group . In the normoglycemic groups there was no significant change in the blood glucose levels for all the groups that were given different doses, after 1 hour of extract administration compared to the control. After 3 hours there was a significant decrease in group given 500mg/kg of extract when compared to control group. However after 5 and 7 hours there was a significant decrease in the groups given 500 and 1000mg/kg bodyweight of extract when compared to the control group. In regard to group given 1500mg/kg bodyweight of the extract all the results revealed no significant change in the blood glucose levels when compared to control untreated. However after 1hour there was a significant increase (P<0.05) in the groups given 1000mg/kg of the extract when compared to the insulin-treated group. After 3 hours there was a significant increase in the group given 500 and 1000mg/kg bodyweight when compared to insulin group. However after 5 and 7 hours there was a highly significant increase (P<0.001) in all the groups given the three doses when compared to insulin-treated group . The histopathological effects on the pancreas of the streptozocininduced diabetic Wistar rats revealed focal areas of necrosis and degenerated pancreatic cells, while the livers revealed congested blood vessel of the hepatic cells. In the normoglycemic groups, there were no any observable microscopic lesion in the pancreas These results show that the extract of Azadiracta Indica has a blood glucose lowering effects in both streptozocin-treated and normoglycemic Wistar rats. This may be due to insulin like action of the extract of Azadiracta Indica seed on the peripheral tissues as well as stimulation of the β-cell.