Inhibition of Plasmodium falciparum growth by a synthetic iron chelator

Abstract
The susceptibility of the chloroquine-resistant malaria parasite Plasmodium falciparum (FCR-3) to a pyridoxal-based iron chelator was tested. 10 μm of the chelator 1 [n-ethoxycarbonylmethyl-pyridoxylidenium]-2-[2′-pyridyl] hydrazine bromide (code name L2–9) effectively inhibited growth in vitro of the parasites. Presaturation of the chelator with either ferric or ferrous iron partially blocked the inhibitory effect. Two hours' exposure of parasites to 20 μm L2–9 was sufficient to inhibit their growth irreversibly. Desferrioxamine blocked the inhibitory effect of L2–9. It is suggested that the chelator may be acting by generating free radicals in complexing intracellular iron.