EFFECTS OF ZINC-DESFERRIOXAMINE ON PLASMODIUM-FALCIPARUM IN CULTURE

The zinc-desferrioxamine (Zn-DFO) complex is considered to be more per meative into parasitized erythrocytes than is the metal-free DFO. The former may penetrate the cell and exchange its bound zinc for ferric i ons, rendering the iron unavailable for vital parasite functions. The effects of these compounds on the in vitro development of Plasmodium f alciparum are compared. The results indicate that Zn-DFO is superior t o DFO, especially at concentrations below 20 mu M, as shown by decreas ed levels of hypoxanthine incorporation, lower levels of parasitemia, and interference with the life cycle of the parasite. At low concentra tions, DFO even enhanced parasite growth. Such an enhancement was not observed following exposure to Zn-DFO. Experiments in which the compou nds were removed from the cultures indicated that parasites treated wi th Zn-DFO are less likely to recover at a later stage. Since DFO has a lready been used in humans for the treatment of malaria, its complex w ith zinc, which is more effective in vitro, should also be examined in vivo.