The effects of N-MPP treatment on P falciparum growth. (A) Parasite growth inhibition with increasing concentrations of N-MPP. Assays were conducted using P falciparum strains 3D7, K1, and W2-mef. Parasites, synchronized at the trophozoite stage, were treated with N-MPP at the indicated concentrations and growth determined relative to an untreated control after 48-hour incubation. Data (±SEM) represent the mean of 2 independent assays for 3D7 and 1 assay for K1 and W2-mef (each concentration was assayed in triplicate). Respective IC50 values (nM ± SE) were: 49.7 ± 2.67, 459 ± 89.2, and 199 ± 43.3. (B) Titration of PPIX against N-MPP treatment. Assays were conducted using P falciparum 3D7 parasites. Parasite cultures were treated with or without 50 μM N-MPP. Growth inhibition was determined relative to an untreated control after 48-hour incubation. Data (±SEM) represents mean of 2 independent assays (each concentration was assayed in triplicate). *P < .05, **P < .01, ***P < .001 compared with untreated cells. SEM, standard error of the mean.
