Phytochemistry and antidiabetogenic property of aqueous extract of Azadirachta indica leaf in streptozotocin-induced diabetic rats

Abstract

Aim: This study was carried out to determine the phytochemicals and the antidiabetogenic property of Azadirachta indica leaf in streptozotocin-induced diabetic male rats. Methodology: The quantitative phytochemical analysis and the glucose levels were checked using standard methods. Different group of rats were pre-treated for seven, fourteen, twenty-one and twenty-eight days before the induction of diabetes to know the extent of protection the extract will have on the rats by preventing the onset of diabetes. At the end of each treatment period diabetes was induced intraperitoneally using 50mg/kg bodyweight of Streptozotocin. Results: The percentage composition of the phytochemicals in the leaves of Azadirachta indica was as follows: Alkaloids (11.36%), cardiac glycosides (6.19%), flavonoid (5.34%), heamaglutinin (6.331%), oxalate (0.0204%), phenol (4.312%), phytate (4.600%), saponin (12.55%), steroid (0.2566) and tannin (6.17%). The result obtained revealed that there was a better protection for the group of rats pretreated for a period of three weeks and four weeks. The percentage decrease in weight after the induction of diabetes for the groups pre-treated for a period of twenty-one days at varying doses of 100, 200 and 400 mg/kg bodyweight was 6.67%, 6.05% and 4.69% respectively which was significantly (p<0.05) different from the normal untreated group (9.90%). The percentage decrease in weight after the induction of diabetes for the groups pre-treated for a period of twenty-one days at varying doses of 100, 200 and 400 mg/kg bw is 7.04%, 5.97% and 2.50% respectively which was significantly (p<0.05) different from the normal untreated group (10.8%). The percentage increase in the fasting blood glucose level for the groups pretreated for a period of twenty-one days at varying doses of 100, 200 and 400 mg/kg bw was 65.4%, 76.3% and 72.4% respectively which is significantly (p<0.05) different from that of the normal untreated group (82.7%) and the group pre-treated with metformin at a dose of 100 mg/kg bw (84.5%). The percentage increase in the fasting blood glucose level for the groups pre-treated for a period of twenty-eight days at varying doses of 100, 200 and 400 mg/kg bw was 73.5%, 68.5% and 64.4% respectively which was significantly (p<0.05) different from that of the normal untreated group (83.3%) and the group pre-treated with metformin at a dose of 100 mg/kg bw (85.5%). The longer the period of pre-treatment, the better the reduction in the blood glucose levels recorded after the induction of diabetes. Conclusion: These results suggest that the aqueous extract of A. indica leaf has antidiabetogenic effect and could be used in the prevention as well as delaying the onset of diabetes mellitus.