FIG. 4.
Dose-dependent synergistic effect of cysteamine on artemisinin efficacy against replication of Plasmodium chabaudi in vivo. Groups (n = 6) of female A/J mice were infected with P. chabaudi (107 pRBC, i.v.) and treated for 4 days (days 0, 1, 2, and 3) with increasing doses (indicated) of artesunate (C) and/or cysteamine (A and B) given i.p. Blood parasitemia was determined at days 4 and 5 postinfection, and the inhibitory effects of the different drug treatments on blood-stage P. chabaudi replication were calculated for each animal compared to the mean of PBS-treated controls (expressed as a percentage). The presence or absence of drug is indicated by a plus or minus, respectively, and all doses are in mg/kg. Errors bars represent standard error of the mean.