In vitro antiplasmodial and cytotoxicity activities of 14 medicinal plants from Kenya

Organic and aqueous extracts obtained from 14 Kenyan medicinal plants were screened for their antimalarial properties on two strains of Plasmodium falciparum (K1 chloroquine resistant and NF54 chloroquine sensitive). Dichloromethane extracts had the highest activities with IC50 ranging from 1.4 to 35.2 μg/ml. These extracts together with methanol extract of Turraea robusta were tested for their cytotoxicity properties in vitro on mammalian L6 cell line. The cytotoxicities ranged from > 90 to 0.34 μg/ml. Selectivity index (IC50 L6 cells/IC50P. falciparum) was also determined. Vernonia lasiopus had the highest selectivity index (SI) of greater than 10 while Warbugia ugandensis had the lowest SI of 0.24. This study suggests that V. lasiopus has a high potential for exploitation as a source of antimalarial agents.