Comparative antitrypanosomal screening of methanolic extracts of khaya senegalensis and <i>Moringa oleifera</i>

Abstract

The in vitro and in vivo activities of methanolic extracts of defatted leaves and stems of Khaya senegalensis and Moringa oleifera on Trypanosoma  brucei brucei were investigated and compared. The in vitro assessment involved incubating the parasite (in triplicate) in the presence of various extract concentrations in a 96-well microtitre plate against negative and  drug controls. The stem extract of Khaya senegalensis and Moringa  oleifera stem extract gave the highest and the least in vitro activities with per cent drop in parasite population of 43.76 and 29.46 respectively. The in vitro results compared well with that of Diminazine Aceturate, a standard trypanocides employed in the control well. Intraperitoneal treatment of T.  brucei brucei-infected mice using these stem extracts at 200 mg/kg b.w.  revealed complete elimination of the parasite from blood circulation in Moringa oleifera –treated animals and suppression of parasitaemia in  Khaya senegalensis-treated group, contrary to expectation raised by the in  vitro findings. Subinoculation experiment with various organ homogenates, however, showed residue of live parasite hidden within organs of infected animal whose parasites were cleared from systemic circulation. The  implications of these findings is discussed.

Keywords: Comparative, Antitrypanosomal activities, Khaya senegalensis, Moringa oleifera, Trypanosoma brucei brucei, Traditional medicine.