Phytochemical investigation, in vitro antimalarial and cytotoxicity assessment of ethanol leaf extract of Sabicea gigantistipula

Phytochemical, in vitro antimalarial and cytotoxicity assessment of ethanol leaf extract of Sabicea gigantistipula (Schum) was investigated on the basis of the usage of the leaves of the plant in traditional medicine by Idoma tribe in Otukpo Benue State and other parts of Northern Nigeria to treat malaria disease. Crude ethanol leaf extract obtained from the plant was fractionated and screened for their antiplasmodial activity (in vitro), existence of bioactive secondary metabolites and for activities in the Artemia salina Leah (Brine Shrimp) lethality assay for cytotoxicity profile. In the phytoconstituents screening, ethanol leaf extract shows the presence of saponins, tannins, flavonoids, alkaloids and steroids. At the maximum test dose of 5000 µg/ml, ethanol extract and its fractions revealed antiplasmodial suppression activity in the range of 85.25% - 91.80% while at the minimum dose of 500 µg/ml, the extract and fractions exhibited malaria parasites percentage elimination activity in the range of 64.75 % - 77.00% showing that the extract and fractions under investigation were less active when compared with the percentage parasitic inhibition of the standard drug at highest concentration of 5000 µg/ml (93.44%) and at the least dosage of 500 µg/ml (81.97%). Interestingly, extract and its fractions were non-cytotoxic as they all exhibited LC50 values > 1000 µg/ml since an extract or its fractions is considered non-cytotoxic if its LC50 value is greater than 1000 µg/ml. The findings of this research supports the continuous use of the extract from the leaves of Sabicea gigantistipula to cure malaria infection (as an antimalarial herb) as it has wide range of safety at relatively low/moderate dose and not at unregulated high dosage. Also, studies on the in vivo antiplasmodial and cytotoxicity of the extract/compounds from the leaf of the crude extract are worthy of further investigations.