Fig. 4.

Effect of varying concentrations of compounds on the growth of Toxoplasma gondii in human foreskin fibroblasts (HFF) cells. Equal amounts (500) of T. gondii tachyzoites constitutively expressing yellow fluorescent protein (YFP) were used to infect confluent monolayers of HFF cells and immediately (solid lines) or 2 h (dashed lines) after infection treated with varying concentrations of compound JS-1-09 (A), JS-2-49 (B), JS-2-35 (C), or JS-2-20 (D). Infected cells without compound-treatment, but with DMSO equivalent to volumes used in compound-treated cells were set as negative controls (DMSO h p.i.). After 48 h, the cultures were analyzed for parasite proliferation by measuring the parasite YFP fluorescence by fluorescence microscopy. The fluorescence generated by T. gondii was quantified and is shown on the Y-axis representing the parasite load. The data shown represent the means from three independent experiments with standard error bars, and levels of statistical significance depicted by asterisks (*, P < 0.05).