Investigation of antihyperglycaemic activity of banana (Musa sp. var. Nanjangud rasa bale) pseudostem in normal and diabetic rats.

ABSTRACT

BACKGROUND: Postprandial hyperglycaemia in diabetes could be ameliorated by inhibiting intestinal α-glucosidases, responsible for starch hydrolysis and its absorption. Different parts of banana have been in use in conventional medicinal formulations since ancient times. Its role as an antihyperglycaemic agent has also been studied. This study was aimed at explaining the mechanism of hypoglycaemic effect by ethanol extract of banana pseudostem (EE). Additionally, studies on the active components involved in the effect have also been attempted. RESULTS: EE significantly inhibited mammalian intestinal α-glucosidases and yeast α-glucosidase (IC50 , 8.11 ± 0.10 µg mL(-1) ). The kinetic studies showed that EE inhibited sucrase, maltase and and p-nitrophenyl-α-d-glucopyranoside hydrolysis by mixed-type inhibition. Further, in vivo studies identified that the oral administration (100-200 mg kg(-1) body weight) of EE significantly suppressed the maltose/glucose-induced postprandial plasma glucose elevation and wielded an antihyperglycaemic effect in normal and alloxan-induced diabetic rats. GC-MS analysis of EE revealed high levels of ß-sitosterol (29.62%), stigmasterol (21.91%), campesterol (10.85%) and other compounds. CONCLUSION: These findings suggest that EE might exert an anti-diabetic effect by inhibition of α-glucosidases from the intestine, in turn suppressing the carbohydrate absorption into the bloodstream. Hence the results extend a foundation to the future prospects of the food-derived enzyme inhibitors in treatment of diabetes.