Kanem Journal of Medical Sciences (Jan 2018)
BIOASSAY GUIDED ISOLATION OF ACTIVE PHYTOCHEMICALS FROM HYPHAENETHEBAICA (L) MART FRUIT PULP METHANOL EXTRACT RESPONSIBLE FOR HYPOGLYCAEMIC ACTIVITY
Abstract
Background: Active phytochemical responsible for hypoglycaemic activity from Hyphaenethebaica (L) Mart were separated using Bioassay guided fractionation. Methodology: Five hundred grams (500g) methanolic fruit extract of H. thebaica was 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 C1, C2, and C3. Finally C1 gave RF value. Diabetes was induced to albino rats of both sexes by intramuscular 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 of 70% methanol extract of Hyphaenethebaica fruit 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 for saponins 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 C1 has more hypoglycaemic activity of 60.50% while phytochemical evaluation showed the presence of flavonoids. Conclusion: Flavonoids may be responsible for the observed hypoglycaemic effect of H. thebaica fruit pulp
