The antifungal activity of methanol and ether extracts of the leaves of <i>Leonotis nepetaefolia</i>

Abstract

A survey done on Rwandese traditional healers revealed that Leonotis nepetaefolia has got many therapeutic uses in Rwanda. This research was carried out on the leaves of this plant to verify its efficacy in the treatment of antifungal diseases. Preliminary phytochemical analysis of leaves of the plant indicated the presence of tannins, flavones, quinones and saponins. The antifungal test of the crude methanol and the crude ether extracts was realized and revealed that crude methanol extract was more active than crude ether extract on Candida albicans and Malassezia fulfur growth. The minimum inhibitor concentration (MIC) of the crude methanol extract were 4.12 mg/ml and 2.38 mg/ml respectively for the growth of C. albicans and M. fulfur while those obtained from crude ether extract were 4.95 mg/ml and 3.7 mg /ml respectively for C. albicans and M. fulfur. Phytochemical screening, physical and biological methods were used to partially characterize the antifungal products contained in the crude methanol extract. Open column chromatography was used to fractionate these compounds and led to seven separated fractions and to the test of each fraction for antifungal activity. Fractions F3 and F7 inhibited completely the growth of C. albicans and M. furfur. The MIC of F3 were found at 1.45 mg/ml and 2.38 mg/ml respectively for C. albicans and M. fulfur while those of F7 were 1.92 mg/ml and 1.45 mg/ml respectively for C. albicans and M. fulfur. Phytochemical screening revealed that tannins and quinones compounds are responsible of this activity.

Key words:Leonotis nepetaefolia , leaves, natural products, phytochemical screening, chromatography, Candida albicans, Malassezia fulfur, antifungal activity.