Antimicrobial activity of extract and topical cream formulation of Mitracapus villosus (Rubiaceae)

Abstract

Crushed leaves of Mitracapus villosus is used in traditional medicine practice for the treatment of skin diseases and its ethnomedicinal use has been established. This study therefore investigated the antimicrobial activities of the crude extract and the cream formulation of Mitracapus villosus aerial parts (leaves, inflorescences and stem) by agar diffusion against four reference bacteria (Staphylococcus aureus, Proteus vulgaris, Escherichia coli and Klebsiella sp.) and reference fungi (Candida albicans). The minimum inhibitory concentration (MIC) obtained for the crude extract was 4 % both for C. albicans and Staph. aureus and 20 % for Klebsiella sp. While E. coli and Proteus vulgaris showed a high degree of resistance to concentrations > 20 %. The MIC for the cream formulations were 5 % for both C. albicans and Staph. aureus, while Klebsiella sp did not show any inhibition even at concentrations > 20 %. The zones of inhibition ranged from 3-22 mm at 4-50 % w/v for the extract (i.e., C. albicans, Staph. aureus and Klebsiella sp) and that for the cream was 3 – 13 mm (i.e C. albicans and Staph. aureus). However, the other organisms did not display any zone of inhibition at all. The results indicate that Mitracapus villosus extract can be formulated into creams for topical application in treating infections caused by susceptible organisms.

Keywords: Mitracapus villosus, topical cream, extraction, antimicrobial activity