Abstract

The ethanolic extract of Chromolaena odorata was fractionated with solvent-solvent extraction technique using the following solvents successively, n-hexane, dichloromethane, ethyl acetate, n-butanol and water. The fractions were evaluated for analgesic, anti-inflammatory and antipyretic activities using standard experimental models which includes; hot plate and formalin paw licking tests for analgesic activities, carrageenan paw oedema and cotton pellet granuloma for anti-inflammatory activities and Brewer’s yeast induced pyrexia for antipyretic tests. The dichloromethane (DCF), n-butanol (nBF) and ethyl acetate (EAF) fractions were analyzed using analytical thin-layer chromatography (TLC), and preparative thin-layer chromatography (PTLC). Spectral studies were carried out using ultra-violet (UV) and infra-red (IR) spectroscopy. Phytochemical screening was carried out on the isolated compounds and the R_f  values were determined. The result shows that the DCF produced consistent analgesic, anti-inflammatory and antipyretic activities followed by the nBF and EAF. Spectroscopic and phytochemical analyses revealed the presence of flavonoid in DCF. Flavonoids were also detected in nBF and EAF. The biological activities of the extract can therefore be attributed to the presence of flavonoids in the fractions.

Key words: Analgesic, anti-inflammatory, antipyretic, Chromolaena odorata, flavonoids, fractions.