In vitro antiplasmodial activity of Tithonia diversifolia and identification of its main active constituent:: Tagitinin C

The antimalarial properties of Tithonia diversifolia, an Asteraceae traditionally used to treat malaria, were investigated in vitro against three strains of Plasmodium falciparum. The ether extract from aerial parts of the plant collected in Sao Tome a Principe, demonstrated good antiplasmodial activity (IC50 on FCA strain: 0.75 mug/ml). A bioassay guided fractionation of this extract led to the isolation of the known sesquiterpene lactone tagitinin C as an active component against Plasmodium (IC50 on FCA strain: 0.33 mug/ml), but also possessing cytotoxic properties (IC50 on HTC-116 cells: 0.706 mug/ml).