Figure 8. Life cycle-dependent sensitivities of P. falciparum to methyl sterculate throughout asexual blood stage growth.

(A) Stage-specific MeSter IC₅₀ value. This value was determined using a range of MeSter concentrations at each stage, following 6 hrs of parasite exposure to the drug. The medium was then removed, cells were washed twice, and fresh medium was added. Viability was determined after 52 hrs by measuring the parasite ability to incorporate [³H]-hypoxanthine for a further 18 hrs. Results are expressed as the mean of 2 independent experiments. (B) Time-course of parasite growth inhibition by MeSter. The upper panel is a schematic representation of the experimental protocol. Drug was added at each developmental stage for the indicated times. The medium was then removed, cells were washed twice, and fresh medium was added. Viability was determined after 52 hrs by measuring the ability of the parasites to incorporate [³H]-hypoxanthine for a further 18 hrs. The graph in the lower panel illustrates the sensitivity of each parasite stage to MeSter as a function of the duration of exposure to compound. Results are expressed as the percent [³H]-hypoxanthine incorporation compared to non-treated parasites, and reflect the mean of 2 independent experiments.