SITOSTEROL-3-O-β-D GLUCOSIDE FROM Acanthus montanus LEAVES EXTRACT AND ITS CONTRACTILE ACTIVITY

Abstract

Based on its ethnomedicinal importance and previous report, leaves extract of Acanthus montanus was investigated in vitro for its contractile activity. The powdered plant leaves were extracted with methanol in a soxhlet apparatus. The crude extract was concentrated in a rotary evaporator at 50oC. Phytochemical screening was conducted according to standard methods and contractile activity was determined using non-pregnant female albino rats with the aid of Ugo Basile Data Capsule Calibrated channel recorder (model 4050). Alkaloids, saponin, glycosides, eugenols and steroids were present while phenolics were absent. The uterine contractile results revealed that the methanol extract of A. montanus produced a significant (p<0.05) decrease in both oxytocin and acetylcholine-induced contractions of the rat uterus. The activity of the extract was comparable to that of salbutamol and atropine; two positive controls that significantly (p<0.05) relaxed the uterus. The most active methanol extract was further separated using vacuum liquid chromatography. Collected fractions were monitored via thin layer chromatography (TLC) and similar fractions were combined. Combined fractions Am3 (A. montanus methanol fraction) gave a white powder with molecular weight of 576.859g/mol (C35H60O6) and a melting point of 264 - 273.50C. Comparison of 1H-NMR, 13C-NMR, IR, UV, MS and Melting Point with that of literature report led to the conclusion that this solid was characteristics of Sitosterol-3-O-β-D-glucoside. The contractile study of this work justifies and supports the traditional use of Acanthus montanus in the treatment and management of threatened abortion and uterine pain by herbal practitioners.  Keywords: contractile, glycoside; 1H NMR; sitosterol; Acanthus montanus.