Antiplasmodial and antipyretic studies on root extracts of Anthocleista djalonensis against Plasmodium berghei

ObjectiveTo evaluate the antimalarial activities of ethanolic root extract/fractions of Anthocleista djalonensis (A. djalonensis) in Plasmodium berghei (P. berghei) infected mice.MethodsA. djalonensis root extract (175–1 000 mg/kg) and fractions (chloroform, ethyl acetate and methanol; 250 and 500 mg/kg) were investigated for antiplasmodial activity against chloroquine-sensitive Plasmodium berghei infections in mice and for antipyretic activity against dinitrophenol, amphetamine and yeast-induced pyrexia. The antiplasmodial activity during early and established infections as well as prophylactic were investigated. Artesunate (5 mg/kg) and pyrimethamine (1.2 mg/kg) were used as positive controls. Antipyretic activity of the crude extract was also evaluated against dinitrophenol, amphetamine and yeast-induced pyrexia.ResultsThe extract and its fractions dose-dependently reduced parasitaemia induced by chloroquine sensitive Plasmodium berghei infection in prophylactic, suppressive and curative models in mice. These reductions were statistically significant (P<0.001). They also improved the mean survival time from 13 to 28 days relative to control (P<0.001). The activities of extract/fractions were comparable to that of the standard drugs used (chloroquine and pyrimethamine). On pyrexia induced by dinitrophenol, amphetamine and yeast, the extract inhibited significantly (P<0.05 – 0.001) and in a dose-dependent fashion temperature rise caused by these pyrogens.ConclusionsA. djalonensis root extract has antiplasmodial and antipyretic activities which may in part be mediated through the chemical constituents of the plant.