Antiprotozoal and cytotoxic activities, and the acute toxicity of extracts from of Brucea sumatrana Roxb. (Simaroubaceae) leaves collected in Mai-Ndombe, Democratic Republic of Congo

Abstract

Results from the in vitro evaluation of the antiprotozoal activity of the aqueous extract, the 80% methanol extract and its fractions from the leaves of Brucea sumatrana against Trypanosoma brucei brucei, Trypanosoma cruzi, Lesihmania infantum, the multidrug-resistant K1 and chloroquine-sensitive NF54 strains of Plasmodium falciparum indicated that all samples from the leaves extract presented interesting antiprotozoal activity at different extents. The 80% methanol extract, its chloroform acid, petroleum ether and 80% methanol soluble fractions and the aqueous extract exhibited strong activity against Trypanosoma b. brucei, T. cruzi, L. infantum and the multidrug-resistant K1 strain of P. falciparum with IC50 values from < 0.25 to 4.35 µg/ml as well as against chloroquine-sensitive NF54 strain of P. falciparum with IC50 values ranging from < 0.02 to 2.0.4 µg/ml. Most samples were cytotoxic against MRC-5 cell lines (0.2 < cytotoxic concentration 50 (CC50) < 24.5 µg/ml) and showed good selective effect against all tested parasites. In acute toxicity, the aqueous extract was found to be non-toxic and its LD50 was estimated to be greater than 5 g/kg. In addition, it did not significantly modify the concentration levels of some evaluated biochemical and hematological parameters in rats. These results constitute a scientific validation supporting and justifying the traditional use of the leaves of B. sumatrana for the treatment of malaria, sleeping sickness and at some extent Chaga disease. Key words: Brucea sumatrana, Simaroubaceae, leaves, extracts, antiprotozoal activity, cytotoxic activity, acute toxicity.