Currently, the treatment of falciparum malaria is seriously compromise
d by spreading drug resistance. We studied the effects of camptothecin
, a potent and specific topoisomerase I inhibitor, on erythrocytic mal
aria parasites in vitro. In Plasmodium falciparum, camptothecin trappe
d protein-DNA complexes, inhibited nucleic acid biosynthesis, and was
cytotoxic. These results provide proof for the concept that topoisomer
ase I is a vulnerable target for new antimalarial drug development. (C
) 1998 Elsevier Science Inc.