Morphological effects of pyronaridine on malarial parasites.

The ultrastructural changes caused by a new antimalarial drug, pyronaridine, were investigated using mice infected with erythrocytic forms of Plasmodium berghei and P. falciparum cultivated in vitro in human erythrocytes. The first changes observed in both parasites after exposure to pyronaridine occurred in the food vacuoles. This suggests that the target organelle of this drug may be the food vacuole of malarial parasites. In addition, rapid alterations were also noted within the pellicular complex of both plasmodia.