Bioassay guided isolation of active phytochemicals from hyphaenethebaica (L) mart fruit pulp methanol extract responsible for hypoglycaemic activity

Abstract

Active phytochemical responsible for hypoglycaemicactivily from Hyphaenethebaica (L) Mart were separated using Bioassay guided fractionation. Methodology: Five hundred grams (500g) methanolic fruit extract of H. thebaicawas suspended in water, filtered and sequentially partitioned with hexane, chloroform, ethyl acetate and n-butanol. The n-butanol fraction was subjected to column chromatography, sub-fraction A, B, C, D, E, F and G were obtained. Further separation using preparative TLC of fraction C afforded sub-fraction C, C, and 1 2 C. Finally, C gaveRF value. Diabetes was induced to albino rats of both sexes by intra muscular 3 1 injection of 120mg/kg Alloxan monohydrate. The diabetic rats were grouped according to the number of fractions and sub-fractions with 3 rats each. Each fraction was tested for hypoglycaemic activity. The one with highest activity was used for next study and phytochemical constituents analysed. Results: The phytochemical screening of70% methanol extract of Hyphaenethebaicafruit pulp were reported to contain saponins, tannins, terpenoids, cardiac glycosides with the exception of alkaloid, combined anthraquinone, free anthraquinone and soluble starch. The n-butanol portion showed hypoglycaemic activity (66.37±1.03% reduction) compared to other fractions at 400mg/kg. The n-butanol portion similarly contained phytochemicals found in crude extract except forsaponins which is absent. The column fraction C of the n-butanol portion has maximum reduction (45.33± 2.80%) of fasting blood glucose of diabetic rats at a lower dose of 200 mg/kg. Sub-fraction C has more hypoglycaemic activity of 1 60.50%while phytochemical evaluation showed the presence of flavonoids. Conclusion: Flavonoids may be responsible for the observed hypoglyceamic effect of H. thebaicsfruit pulp.