Phytochemical screening and antimicrobial evaluation of the methanol extract and fractions of the leaves of <i>Piper umbellatum</i> Linn (Piperaeceae)

Abstract

Piper umbellatum is widely distributed tropical plant species. The plant has been reported to possess an array activity including anti-inflammatory, antioxidant, antifungal, analgesic and skin protection. It is consumed as a vegetable and used ethnomedicinally in the treatment of stomach pain in Edo state, Nigeria. The antimicrobial property of the plant is being advocated. This present study aims at evaluating the phytochemistry of the methanol extract of P. umbellatum including analytical thin layer chromatography of the extract. This study evaluated the antimicrobial activity of the methanol extract of P. umbellatum as well as the n-butanol; n-hexane and chloroform fractions of the extract obtained by partitioning the methanol extract using clinical isolates in agar dilution technique. This study also went further to determine the minimum inhibitory concentration (MIC) of the methanol extract and the n-hexane fraction of the extract. Phytochemical screening of the dry leaves indicated the presence of carbohydrates, cardiac glycosides, saponins, tannins and alkaloids. TLC revealed that a non-polar solvent system is preferable for isolation. The methanol extract, n-hexane fraction and n-butanol fractions inhibited all the test microorganisms at the doses used. The MIC for both the methanol extract and n-hexane fraction were found to be <25mg/ml. This study therefore confirms the antimicrobial activity of Piper umbellatum.

Keywords: Piper umbellatum; Methanol extract; Antimicrobial activity; Phytochemistry; Chromatography