Activity of extracts and isolated naphthoquinones from Kigelia pinnata against Plasmodium falciparum

Four naphthoquinoids from Kigelia pinnata rootbark were assessed in vitro against chloroquine-sensitive (T9-96) and -resistant (K1) Plasmodium falciparum strains and for cytotoxicity using KB cells. 2-(1-Hydroxyethyl)naphtho[2,3-b]furan-4,9-dione possessed good activity against both strains [IC50 values 627 nM (K1), 718 nM (T9-96)]. Isopinnatal, kigelinol, and isokigelinol exhibited lower activity against both strains.