Phytochemical Evaluation and Anti-inflammatory Activity of the Leaf, Stem and Root bark Extracts of Strophanthus sarmentosus DC.

Abstract

Strophanthus sarmentosus DC commonly called arrow poison or spider tresses is a very popular plant among traditional medical practitioners in Africa and is used to treat arthritis and wound infections. This study was carried out to qualitatively and quantitatively determine the phytochemical composition and the antiinflammatory activities of different solvent extracts of S. sarmentosus.The anti inflammatory activity was studied using egg albumin-induced inflammation of rat paw oedema. The crude extracts of the leaf, root bark and stem extracts obtained using n-hexane, dichloromethane and methanol were administered at concentrations of 200 and 400 mg/kg body weight of the animals. The phytochemical analysis revealed the presence of alkaloids, flavonoids, saponins, tannins, terpenoids and glycosides in varying proportions. The anti-inflammatory activity of all the extracts revealed significant (p > 0.05) anti-inflammatory effect with maximum suppression occurring at the fifth hour. The root bark extract had the highest mean % inhibition at both concentration of 200 and 400 mg / kg body weight of the animals, with 63.59 and 79.30 mean % inhibitions, although at the highest dose of 400 mg / kg, the extracts were found to be lethal to the animals. Of the three partitioned stem fractions, the n-hexane fraction had the highest mean % inhibition and a 100% inhibition at the fifth hour. From their mean % inhibitions, all the extracts had increased suppression of inflammation with increase in the concentration of administered dose from 200 to 400 mg/kg body weight. There was no noticeable suppression observed for the methanol fraction of the stem extract. The marked inhibitory effect on paw oedema shows that Strophanthus sarmentosus possesses significant anti-inflammatory activity, thus justifying the use of the plant in the treatment of various inflammatory diseases by traditional medical practitioners.