Laportea aestuans has folkloric application in African herbal remedies for the treatment of inflammatory conditions. Over the years this medicinal plant has been traditionally used in Africa ethnomedicine in the treatment of several diseases associated with pains, fever and inflammation but without much scientific fractionation and characterization of biomolecular constituents and therefore, the rationale behind this research. The crude ethanol extract has demonstrated anti-inflammatory potential, the specific bioactive fractions and their phytochemical constituents remain uncharacterized. To fractionate and characterize the phytochemical principles of solvent fractions of ethanol leaf extract of Laportea aestuans and determine their anti-inflammatory activity using animal models, crude ethanol extract of L. aestuans leaves was fractionated into n-hexane, dichloromethane, ethyl acetate, and aqueous ethanol fractions. Phytochemical analysis of each fraction was conducted and evaluated on animal models. Anti-inflammatory activity was assessed using carrageenan-induced paw edema model in Wistar rats. Standard drug aspirin (10 mg/kg) was used and compared with the various fractions of the solvents. The statistical analysis was conducted using one-way ANOVA. Phytochemical screening revealed differential distribution of bioactive compounds across fractions. Flavonoids and alkaloids were most abundant in the ethyl acetate and dichloromethane fractions. The dichloromethane and ethyl acetate fractions exhibited significant (p<0.05) inhibition of paw edema, with the ethyl acetate fraction showing activity comparable to standard drug; aspirin. Solvent partitioning enhanced identification of active fractions of L. aestuans responsible for its anti-inflammatory activity. The characterisation and structural elucidation of the ethyl acetate fraction was carried-out with Gas Chromatography-Mass Spectrometry (GC-MS). The GC-MS analysis of the ethyl acetate fraction of Laportea aestuans identified 9, 12- Octadecadienoic acid, 9, 12, 15- Octadecatrienoic acid, Tetradecanoic acid, Oleic acid methyl ester, Dodecanoic acid and other methyl ester and alkanes. These bioactive principles possess anti-inflammatory properties and thus, provided insight into the mechanisms of action.

Keywords: Laportea aestuans, solvent fractions, anti-inflammatory activity, characterisation, carrageenan model.