<i>In Vitro</i> Antiprotozoal and Cytotoxic Activity of the Aqueous Extract, the 80% Methanol Extract and Its Fractions from the Seeds of <i>Brucea sumatrana</i> Roxb. (Simaroubaceae) Growing in Democratic Republic of Congo

Abstract

The in vitro antiprotozoal and cytotoxic activity of the aqueous extract, the 80% methanol extract, and its different soluble fractions and subfractions from Brucea sumatrana seeds were assessed against two Trypanosoma ( T. cruzi and T. brucei brucei ), Leishmania infantum and chloroquine and pyrimethanine-resistant K1strain of P. falciparum and against MRC-5 cell-lines respectively. Results indicated that the 80% methanol extract showed a cytotoxic effect against MRC-5 cell lines with CC 50 value of 0.54 μg/ml. It however exhibited pronounced and non selective activity against T. cruzi (IC 50 = 1.52 μg/ml, SI = 0.03) and L. infantum (IC 50 = 2.41 μg/ml, SI = 0.22). It however displayed pronounced and selective effect against T. brucei brucei (IC 50 < 0.25, SI > 2.16) and chloroquine and pyrimethamine-resistant K1 strain of P. falciparum (IC 50 < 0.25 μg/ml, SI > 2.16). All soluble fractions and subfractions from the partition of the 80% methanol extract were found to exhibit an antiprotozoal activity with IC 50 values ranging from <0.25 to 30 μg/ml. The most active was the alkaline aqueous soluble fraction exhibiting pronounced antiprotozoal activity against T .cruzi , T. b. brucei , L. infantum and chloroquine and pyrimethamine-resistant K1 strain of P. falciparum with IC 50 values of 0.33, <0.25, 0.25, <0.25 μg/ml respectively resulting in high selective index values of 61.36, > 81, 81 and >81 respectively. The chloroform soluble fraction rich in alkaloid was cytotoxic against MRC-5 cell lines (CC 50 = 27.09 μg/ml) and showed good activity against T. b. brucei (IC 50 = 8.36 and SI = 3.24) and moderate activity against T. cruzi , L. infantum and chloroquine-pyrimethane-resistant K1 strain of P. falciparum (20 < IC 50 < 30 μg/ml). Although the aqueous extract (decoction) and the total alkaloids extract showed a cytotoxic effect against MRC-5 cell lines (CC 50 = 1.55 and 0.43 μg/ml respectively), they however displayed pronounced antiprotozoal activity against T. cruzi , T. b. brucei and chloroquine and pyrimethamine-resistant K1 strain of P. falciparum with IC 50 values ranging from < 0.25 to 0.6 μg/ml with only a selective action against chloroquine and pyrimethamine-resistant K1 strain of P. falciparum (SI = >6.2 and >1.72 respectively). These extracts however showed good and low activity respectively against L. infantum (IC 50 = 24.05 and 6.82 μg/ml respectively).