The antileishmanial activity of extracts of Warburgia ugandensis (family Canellaceae), a known traditional therapy and one of the commonly used medicinal plants in Kenya was evaluated. Extracts of this plant were tested for possible antileishmanial activity in vitro. Different doses of hexane, dichloro-methane, Et acetate and methanol extracts of W. ugandensis were tested against Leishmania major and Leishmania donovani promastigotes and amastigotes. The hexane extract had the best activity against L. major promas-tigotes and amastigotes with IC50 value of 9.95 for promastigotes and 8.65 for amastigotes and min. inhibition concentrations of 62.5 μg/mL. The activity of the hexane extract on amastigotes was comparable (P > 0.05) to that of pentostam and amphotericin B. Similar results were obtained for L. donovani withIC50 values of 8.67 for promastigotes and 100-fold reduction of amastigotes in macrophage cultures. Warburgia ugandensis had lower levels of toxicities compared to pentostam and amphotericin B. This study scientifically demon-strates the potential of W. ugandensis in the treatment of leishmaniasis.
