Anti-onchocercal and antibacterial Activities of crude extracts and Secondary Metabolites from the Rhizome of Anchomanes difformis (Araceae)

Abstract

The methanol (MeOH) extract of Anchomanes difformis(Araceae) was fractionated by column chromatography and some pure compounds were obtained whose structures were determined by ¹H and ¹³C-NMR spectroscopy. The extract was tested in vitro for anti-onchocercal activity against O. ochengi, a close relative of O. vulvolus. The MeOH extract showed 100% inhibition of O. ochengi microfilarial activity. Compounds 1, 2 and 3 which were identified as (Z)-12-heptadecenoic acid (1), hexadecanoic acid (2) and â-stigmasterol (3) showed no anti-onchocercal activity against the microfilariae, but 1 and 2 showed weak antibacterial activity against E. coli with erythromycin included as reference.The present study constitutes the first report on the antifilarial activity of Anchomanes difformis and lends credence to the traditional use of juice from the rhizome in the management of river blindness.

Key words: Anchomanes difformis, Onchocerciasis, Antibacterial, Antifilarial