Antiplasmodial activity of plant extracts used-in west African traditionalmedicine

Five plants originating from Ivory Coast were selected after an ethnobotani cal survey, Alchornea cordifolia, Mitragyna inermis, Nauclea diderrichii, P terocarpus santalinoides, and Terminalia glaucescens. Traditional healers f or the treatment of malaria commonly used these plants. Extracts of these p lants were tested on three strains of Plasmodium falciparum, FcB1-Colombia and FcM29-Cameroon (chloroquine-resistant strains) and a Nigerian chloroqui ne-sensitive strain. Extracts were obtained by preparing decoction in water of the powdered plant, the technique used by most of the traditional heale rs. A radioactive micromethod allowed the evaluation of the in vitro activi ty of the extracts on P. falciparum. Concentrations inhibiting 50% of the p arasite growth (IC50) ranged from 2.34 to more than 500 mug/ml according to the plant. For the most active plants(A. cordifolia and T. glaucescens) et hanol and pentane extracts were made and tested. The IC50 values obtained f or these extracts ranged from 0.35 to 43.40 mug/ml. The stage specificity o f the ethanol extracts of A. cordifolia and T. glaucescens and pentane extr act of T. glaucescens on the parasite erythrocytic cycle were determined. T he ethanol extract of T. glaucescens showed its highest activity at the tra nsition from the trophozoite to the schizont stages. Cytotoxicity was estim ated on human fibroblasts (HeLa) cells and a cytotoxicity/antiplasmodial in dex was calculated, it ranged between: 5 and 21, and the best:antiplasmodia l extract (T, glaucescens ethanol extract) had the higher index (>20). (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.