Antimalarial and Antiplasmodial Activity of Leaf Extract of Alchornea Laxiflora

Alchornea laxiflora leaf extracts and their fractions used traditionally in the treatment of malaria by Nigerian tribal populations were investigated for antimalarial activity against Plasmodium berghei using a rodent malaria model and in vitro activity against chloroquine-sensitive (Pf 3D7) and -resistant (Pf INDO) strains of P. falciparum using the SYBR green assay method. Determination of median lethal dose and cytotoxic activities against HeLa and HEKS cells were carried out. The most active extract fraction was analyzed by gas chromatography-mass spectrometry (GC-MS). The leaf extract (200–600 mg.kg−1, p.o.) with LD50 of 2,236 mg.kg−1 were antimalarial against P. berghei infection in suppressive, prophylactive, and curative tests. The crude extract and the fractions exerted prominent activity against both chloroquine-sensitive (Pf 3D7) and -resistant (Pf INDO) strains of P. falciparum. The ethyl acetate fraction exerted the highest activity, with IC50 values of 9.92 ± 0.28 μg.mL−1 (Pf 3D7) and 7.51±0.24 μg.mL−1 (Pf INDO). The crude ethanol extract and ethyl acetate fraction were cytotoxic to the two cell lines tested with TC50 of 1.41–42.04 μg.mL−1 against HeLa and HEKS cell lines.