Abstract: 　Objective To investigate the in vitro antimalarial effect of daphnetin relating to its iron-chelating activity. Methods Schizontocidal activity of daphnetin and desferrioxamine B was tested through an in vitro assay based on the routine in vitro cultivation of Plasmodium faciparum FCC1 strain. The iron-chelating ability of each was measured by the fluorescent probe calcein. Results Daphnetin exhibited a modest iron-chelating ability compared with the powerful iron-chelator desferrioxamine B. In vitro test at the range of 0-12 μmol/L daphnetin showed a dose-dependent schizontocidal activity which could be inhibited if mixed with Fe 2+ in a ratio of 2∶1. Conclusion The dose-dependent antimalarial activity of daphnetin is related to its iron-chelating activity.

Key words: Plasmodium falciparum, daphnetin, desferrioxamine B, calcein