The interaction of artemisinin with red cell membranes.

Artemisinin (qinghaosu) and its derivatives are endoperoxide-containing compounds that are an important new class of antimalarial drugs. Tritiated dihydroartemisinin is taken up and concentrated by isolated red cell membranes but not by intact erythrocytes. More than half of the membrane-associated drug can be released by treatment with phospholipase A2 followed by extraction with ethyl acetate. The remaining drug appears to be bound to the major red cell membrane proteins. There is no association of the drug with either the membrane or cytoplasm of intact red cells. Thus dihydroartemisinin appears to be taken up by isolated membranes, where it associates with proteins but not via intact red cells.