Bio-Assay Guided Fractionation and Isolation Of Anti-inflammatory Compound from Crataevaadansonii Stem Bark Extract

Abstract

This study is aimed at fractionating and isolation of the anti-inflammatory bioactive compound of Crataevaadansonii stem bark extract. The stem bark powder (7.147 kg) was extracted with 1:1 (v/v) mixture of dichloromethane/methanol in a soxhlet apparatus (60°C). The extract obtained was successively fractionated with n-hexane, ethylacetate, dichloromethane and methanol (100%). The extract and fractions were subjected to biological activity-guide studies for anti-inflammatory activity using the egg-albumin induced rat hind paw edema method as activity-guide. Ethylacetate fraction, the most active was subjected to further separation in silica gel column eluted with graded mixtures of n-hexane and ethylacetate which afforded different ethylacetate sub-fractions. Standing EF2 sub-fraction under reduced temperature (4°C) yielded a white crystalline solid (C.adansonii Compound; CA1 identified as triterpene). The extract was further subjected to formaldehyde-induced chronic inflammation tests in rats. The stem bark powder, extract, and fractions were subjected to qualitative and quantitative phytochemical analyses using standard protocols. The extract at a lower dose exhibited stronger reduction on the global edematous response due to arthritis.