Abstract

The methanol extract of the stem bark of Nauclea latifolia was evaluated for its bioactive constituents and antiplasmodial properties.The extract was investigated against chloroquine sensitive plasmodium berghei berghei infection in 90 albino mice. The antiplasmodial activity during prophylactic, early and established infections were investigated. Films made from tail blood of each mouse were used to access the level of parasitaemia of the mice. The extract dose dependently reduced parasitaemia induced by the plasmodium infection in prophylactic, suppressive and curative models in mice.  Phytochemical analysis revealed that the extract contain alkaloids, cardiac glycosides, terpenes, polyphenols, saponins, flavonoids, carbohydrates, phlobatannins and anthraquinones,  Balsams and resins .  The toxicity study revealed that the extract has an LD₅₀. of 3.7mg/kg.  At a dose of 1110mg/kg the  extract reduced parasitaemia from 17.55±0.14 to 4.33±0.54 compared to control translating to 75.32% chemosuppression.  Artesunate, a standard antimalarial drug (positive control) reduced the parasitaemia to 2.59±0.66 translating to 85.24% chemosuppression. These reductions were statistically significant at P<0.05. The extract also improved the mean survival time from 10 to 23 days compared to control (PNauclea latifolia is active against Plasmodium berghei berghei and by extension can be used in the treatment of malaria.    The bioactive constituents present in the extract could be responsible for the antiplasmodial activity.