Antimalarials

Antimalarials are used to treat malaria, a disease caused by protozoan parasites of the Plasmodium genus, which are transmitted by female Anopheles mosquitoes. Most of these compounds target the erythrocytic stage of the infection. Quinoline derivatives such as a chloroquine and mefloquine act by accumulating in the parasite food vacuole and inhibiting the biocrystallization of hemozoin, a breakdown product of hemoglobin, resulting in accumulation of cytotoxic heme. The action of Artemisinin, a Chinese herb, and its derivatives appears to involve the heme-mediated cleavage of endoperoxide bridges to produce free radicals.