helianthus annuus leaf ameliorates postprandial hyperglycaemia by inhibiting carbohydrate hydrolyzing enzymes associated with type-2 diabetes

background: diabetes mellitus is a chronic disease. decreasing postprandial hyperglycemia by retarding glucose absorption through inhibiting carbohydrates digesting enzymes (α-amylase and α-glucosidase) is one of many approaches used for the management of this disease. this study was aimed at evaluating the normoglycaemic potential of helianthus annuus leaf. methods: the effect of the in vitro inhibitory of different extracts (acetone, ethyl acetate and hexane) of the plant was assessed on the activities of diabetes-related enzymes (α-amylase and α-glucosidase). results: the hexane extract of h. annuus leaf displayed the best inhibitory activity against α-amylase and α-glucosidase as indicated by the ic50 values (3.92 ± 0.02 mg ml-1) and (3.29 ± 0.12 mg ml-1), respectively. lineweaver-burk plot of inhibition of α-amylase and α-glucosidase by this extract showed that it was competitive and non-competitive mode, respectively. conclusion: h. annuus leaf possesses hypoglycaemic potential which may be due to the inhibition of pancreatic α-amylase and intestinal α-glucosidase.