Preliminary studies on Piliostigma thonningii Schum leaf extract: Phytochemical screening and in vitro antimalarial activity

Different parts of Piliostigma thonningii Scum (Caesalpinioideae) have been used medicinally. The roots and twigs have been used locally in the treatment of dysentery, fever, respiratory ailments, snake bites, hookworm and skin infections in Eastern Nigeria. The leaf extracts has been used for various ethnomedicinal purposes including the treatment of malaria all over Eastern Nigeria. In this study, we have investigated the inhibitory effects of the crude ethanol and methanol extracts for in vitro antimalarial activity against chloroquine resistant Plamodium Falciparum clone (W2-Indo-China isolates). The aqueous screening using reported methodologies for phytochemical screening and in vitro test methods, revealed the presence of alkaloids, tannins, saponnins, steroid, terponoids, flavonoids, cardiac glycosides and anthroquinoes. The crude leaf extracts obtained were tested for in vitro antimalarial activity using chloroquine resistant strain of P. Falciparum clone (W2 -Indochina isolates). The 50% inhibitory concentrations (IC50) were evaluated after 48 - 72 h contacts between the extracts and the parasite culture. The 50% inhibitory concentration values for both the crude amide ethanolic extract and the partially purified methanolic extract ranged between 6.20 - 15.06 mu g/ml. While that of chloroquine was 0.316 mu g/ml. This study suggested that P. thonningii leaf extract possess a significant level of antimalarial activity.