MORPHOLOGIC EFFECTS OF ARTEMISININ IN PLASMODIUM-FALCIPARUM

Ultrastructural changes induced in Plasmodium falciparum by artemisini n were studied in vitro. Electron microscopic autoradiography was perf ormed on infected erythrocytes that were exposed in vitro to H-3-dihyd roartemisinin and C-14-artemisinin. These drugs consistently were loca ted in food vacuoles and mitochondria. Two hours after administration, changes were observed in parasite mitochondria, rough endoplasmic ret iculum, and nuclear envelope. At four hours, in addition to the earlie r changes, nuclear membranes and, to a lesser extent, some plasma memb ranes formed myelin figures. In addition, there was a disappearance of ribosomes, and a destruction of food vacuole membranes. These changes may lead to the total disorganization of the parasites. Approximately 30% of the parasites manifested these alterations.