Hypoglycaemic and hypolipidaemic effects of crude extracts and chromatographic fractions of Morinda morindoides root bark in diabetic rats

Abstract

Hypoglycaemic and hypolipidaemic effects of different extracts and fractions of root bark from the plantMorinda morindoides(Baker) Milne-Redh of the familyRubiaceaewere evaluated in alloxan-induced diabetic rats. The aqueous and methanolic extracts were administered to 48 rats orally at a dose of 400 mg·kg-1for 21 days.Fractions (hydromethanol, hexane, chloroform and ethyl acetate) from bio-activity guided fractionation and chromatographic sub fractions (CsF) A-F from accelerated gradient chromatography were also evaluated in 45 rats for the hypoglycaemic activity at doses of 400 mg·kg-1, 200 mg·kg-1and 100 mg·kg-1of solvent fractions and (CsF) A-F, respectively. Glibenclamide was used as positive control. Polyoxyethylene sorbitan monooleate and distilled water administered to rats were used as negative controls. The dose of 400 mg·kg-1of aqueous and methanolic extracts and 100 mg·kg-1of chloroformCsFB ofMorinda morindoidescaused (62.8%, 56% and 74%, respectively) reductions in blood glucose level (BGL). The aqueous extract caused significant (P< 0.05) decreases in the values of serum cholesterol (133.48 ± 1.1) mg·dl-1, low density lipoprotein (66.38 ± 2.5) mg·dl-1and significant (P< 0.05) increase in the value of high density lipoprotein (51.03 ± 3.0) mg·dl-1when compared to the control. These results confirm the folkloric claim of the hypoglycaemic and hypolipidaemic activities ofMorinda morindoidesroot bark.