Plasmodium falciparum: Activity of artemisinin against Plasmodium falciparum cultured in sickle trait hemoglobin AS and normal hemoglobin AA red blood cells.

The presence of sickle hemoglobin causes accumulation of hemoglobin degradative products that favor oxidative reaction in erythrocytes. Artemisinin derivatives exert antiparasite effects through oxidative reactions within infected erythrocytes. Using [(3)H]-hypoxanthine incorporation, we therefore did an in vitro comparison of IC(50) values for artemisinin in Plasmodium falciparum-infected erythrocytes from sickle cell trait (AS) and normal (AA) individuals. IC(50) values for chloroquine served as control. Without drugs, parasite growth was similar in AA and AS erythrocytes. Gender, age and blood group of donors had no significant effects on parasite growth. IC(50) value for artemisinin was 27+/-14nM in AS (N=22) compared to 24+/-9nM (N=27) in AA erythrocytes (P=0.4). IC(50) values for chloroquine were also similar in AA (22+/-8nM) and AS (20+/-11nM) erythrocytes. These results show no evidence of elevated artemisinin activity on P. falciparum in AS erythrocytes in vitro.