Inhibitory effect of banana (Musa sp. var. Nanjangud rasa bale) flower extract and its constituents Umbelliferone and Lupeol on α-glucosidase, aldose reductase and glycation at multiple stages

摘要

Postprandial hyperglycaemia is characterized as the ear\udliest symptom of diabetes and its management attenuates\udseveral of the associated secondary complications. In this context, we investigated the role of ethanol extract of ba-\udnana\udfl\udower (EF) for its antihyperglycaemic effect\uds. The EF showed a strong inhibition towards\udα\ud-glucosidase and\udpancreatic amylase which play a vital role in clinical mana\udgement of postprandial hyperglycaemia. The major active\udcompounds present in EF were identi\udfi\uded as Umbelliferone (C1) and Lupeol (C2) using various spectroscopic\udmethods. C1 (IC\ud50\ud:7.08±0.17\udμ\udg/ml) and C2 (IC\ud50\ud:7.18±0.14\udμ\udg/ml) were found to inhibit\udα\ud-glucosidase in a\udnon-competitive mode of inhibition, with low K\udi\udvalues. Further,\udin vitro\udglycation assays showed that EF and its\udcompounds prevented each stage of protein glycation and formation of its intermediary compounds. EF, C1 and\udC2 also exhibited a potent inhibition on aldose reductase with IC\ud50\udvalues of 2.25 ± 0.29, 1.32 ± 0.22 & 1.53 ±\ud0.29\udμ\udg/ml respectively. Our results suggest that, the observed potential of EF in antihyperglycaemic activity\udvia\udinhibition of\udα\ud-glucosidase and in antidiabetogenic effect by inh\udibition of polyol pathway and protein glycation is\udmore likely to be attributed to the presence of C1 and C2