Antifungal Activity of Traditionally Used Tanzanian Plants

Objectives: The purpose of this study was to identify and obtain information on the plants that are used by traditional healers in the management of fungal infections and determine their in-vitro antifungal activities against Candida species, Cryptococcus neoformans and Aspergillus fumigatus. Methods: Using the ethnobotanical approach, some Tanzanian plants reported to be used by traditional healers for the treatment of oral candidiasis and skin fungal infections were collected and screened for their antifungal activity against Candida albicans, C. glabrata, C. tropicalis, C. parapsilosis, C. krusei, C. neoformans and A. fumigatus. A total of 65 crude methanol extracts belonging to 56 plant species and 38 families were screened using the broth microdilution method, according to the guidelines of the Clinical and Laboratory Standard Institute (CLSI) (Formely, National Committee for Laboratory Standards) (NCCLS, 2002). Results: Among the tested extracts, 40% (25 species) showed antifungal activity against one or more of the test fungi. None of the tested plant extract was active against A. fumigatus. The most susceptible yeasts were C.neoformans, followed by C.krusei, C.tropicalis, and C. parapsilosis. C.albicans and C. glabrata were the least susceptible. Strong antifungal activity was exhibited by extracts of Clausena anisata Oliv, Sclerocariya birrea Sond, Turraea holstii Gurk, Sterculia africana (Lour) Fiori, Acacia robusta subsp Usambarensis (Taub) Brenan, Cyphosterma hildebrandti (Gilg), Desc, Elaeodendron buchannanii (Lows), Acacia nilotica (L) Wild ex Del, Jatropha multifida L, and Pteridium aquilinum (L.) Kuhn. Conclusions: Results of the present study suggest a fairly good correlation between traditional therapeutic use and the invitro antifungal activity and corroborate the importance of ethnobotanical surveys for screening plants as a potential source for bioactive compounds. Hence these could result in discovery of novel antifungal agents. Further bio-guided fractionation will be conducted for the active plants to identify the active compounds.