Antifungal activity of selected species of Terminalia, Pteleopsis and Combretum (Combretaceae) collected in Tanzania

Thirty-five crude extracts of 5 species of Terminalia, 10 species of Combretum (Loefl.) and Pteleopsis myrtifolia (Laws.) Engl. & Diels. collected in Tanzania were investigated for their antifungal activity against 5 species of Candida and Cryptococcus neoformans. An agar diffusion method was used for the antifungal screening, and species of Terminalia (L.) and Combretum were chosen according to their uses in Tanzanian traditional medicine. Candida glabrata and Cryptococcus neoformans were the most sensitive organisms in this antifungal screening, and the root extracts of Terminalia sambesiaca Engl. & Diels., T sericea Burch. ex DC., T kaiserana E Hoffm., Combretum padoides Engl. & Diels., and C. molle G. Don. showed significant inhibition of the growth of these two fungi. The best screening results were obtained with root extracts of T sambesiaca, T kaiserana, and T sericea, which gave low MIC-values against Candida glabrata and Cryptococcus neoformans. A root extract of T sericea gave nearly as low MIC values (0.78 mg/ml) as amphotericin B (0.20 mg/ml) against Candida glabrata. This investigation encourages us to search for antifungally active compounds from among the most active species of Terminalia and Combretum.