Simaomicin α: Effects on the cell cycle of synchronized, cultured Plasmodium falciparum

Abstract

Simaomicin α shows potent antimalarial activity in vitro and is known to be a cell-cycle effector. As erythrocytic schizogony of Plasmodium correlates with cell cycle events, we investigated the effect of simaomicin α on stage development of the malaria parasite Plasmodium falciparum. Simaomicin ∞ interferes with normal parasite development in a time and concentration dependent manner. Parasites exposed to 2.5 nM simaomicin α at the ring stage or trophozoite stage showed disrupted development and immature schizont-like and segmenter-like forms were observed. However, schizont stage parasites were not affected by 2.5 nM simaomicin α. It is unclear whether mitosis involved in sequential parasite development occurred when parasites were exposed to simaomicin a at the ring or trophozoite stage. At a concentration of 5.0 nM, simaomicin α inhibited merozoite-trophozoite development. This concentration curtails p-LDH activity at all parasite stages, although its impact on the schizont stage is delayed for 24 hours. © Japan Antibiotics Research Association.