EFFECT OF LEAF EXTRACT AND PHENOL RICH FRACTION OF MILLETTIA ABOENSIS ON ORAL GLUCOSE TOLERANCE AND CARBOHYDRATE METABOLIZING ENZYME

M. aboensis is rich in bioactive compounds, including flavonoids, phenolics, alkaloids, and terpenoids which has a long history of traditional medicinal use, particularly for treating diabetes and related metabolic disorders. This study evaluated the effect of leaf extract and phenol rich fraction of Millettia aboensis on oral glucose tolerance and carbohydrate metabolizing enzyme. The plant was extracted by cold maceration method using methanol and was fractionated with n-hexane, ethyl acetate and butanol in increasing order of polarity and concentrated. Phytochemical, total phytoestrogen and total phenolic content was carried out from the extracts and fractions obtained. The acute toxicity study was conducted with a limit test at 2000 mg/kg and oral glucose tolerance was conducted by giving 2 g of starch and M. aboensis extract in different concentration at 200 mg/kg, 400 mg/kg, and 800 mg/kg. Graded doses of phenol-rich fraction (ethyl acetate) was tested for its ability to inhibit alpha-amylase activity. The ethyl acetate fraction has highest phytoestrogen content of 115 mg GenesteinEq/g and highest phenolic content of 485.93 mgGAE/g. Acute toxicity revealed no death in all animals throughout the 14 days duration of study but an increase in locomotor activity was observed after the first 24 hours. Compared to basal blood glucose level (0h), significant (P < 0.05) increase in blood glucose was recorded from 15 – 90 minutes post starch administration in the 200 and 400 mg/kg ethyl acetate fraction treated group. In vitro testing showed that phenol-rich fraction had moderate α-amylase inhibitory activity. In the light of finding of acute toxicity studies, it can be concluded that the plant may be relatively safe after acute oral administration. In conclusion, the ethyl acetate fraction showed inhibition of alpha amylase and improved glucose tolerance which may be beneficial in the management of diabetes. This may be attributed to the phytoestrogen and phenolic constituent present.