The in vitro activities of the aqueous and ethanolic extracts of the leaves, root bark and stem bark of Khaya senegalensis on Trypanosoma evansi were evaluated. The ethanolic extract of the stem bark was found to possess the highest in vitro activity among the six extracts tested; as it eliminated the parasites within 5 min post incubation at concentrations of 0.5 and 1 mg/ml. This extract was therefore used to treat rats experimentally infected with T. evansi at concentrations of 20, 40 and 80 mg/kg body weight, beginning 7 days post infection (p.i). At the termination of the experiment on day 13 p.i, the stem bark ethanolic extract significantly (P < 0.05) kept the parasitemia lower than was observed in the untreated infected rats, whereas the parasites were eliminated from the bloodstream of Diminal-treated rats at day 9 p.i. All the infected animals developed anaemia whose severity could not be ameliorated by the extract treatment. It was therefore concluded that the stem bark ethanolic extract of K. senegalensis possessed both in vitro and in vivo anti-T. evansi activity but could not prevent the disease –induced anaemia.

 

Key words: Khaya senegalensis, Trypanosoma evansi, anti – trypanosomal.