In vitro α-amylase inhibitory activity and in vivo hypoglycemic effect of methanol extract of Citrus macroptera Montr.fruit

Objective:To investigate the therapeutic effects of methanol extract of Citrus macroptera Montr,fruit inα-amylase inhibitory activity(in vitro)and hypoglycemic activity in normal and glucose induced hyperglycemic rats(in vivo).Methods:Fruits of Citrus macroptera without rind was extracted with pure methanol following cold extraction and tested for presence of phytochemical constituents,α-amylase inhibitory activity,and hypoglycemic effect in normal rats and glucose induced hyperglycemic rats.Results:Presence of saponin,steroid and terpenoid were identified in the extract.The results showed that fruit extract had moderateα-amylase inhibitory activity[ICvalue=(3.638±0.190)mg/mL]as compared to acarbose.Moreover at 500 mg/kg and 1000 mg/kg doses fruit extract significantly(P<0.05 and P<0.01 respectively)reduced fasting blood glucose level in normal rats as compared to glibenclamide(5 mg/kg).In oral glucose tolerance test,500 mg/kg dose significantly reduced blood glucose level(P<0.05)at 2 h but 1000 mg/kg dose significantly reduced blood glucose level at 2 h and 3 h(P<0.05 and P<0.01 respectively)whereas glibenclamide(5 mg/kg)significantly reduced glucose level at every hour after administration.Overall time effect is also considered extremely significant with F value=23.83 and P value=0.0001 in oral glucose tolerance test.Conclusion:These findings suggest that the plant may be a potential source for the development of new oral hypoglycemic agent.