Fig. 6.

Specificity of the PfENT1 inhibitors for the malaria transporter compared with the human RBC hENT1 transporter. (A) Inhibition of 50 nM [³H]adenosine uptake into RBC-free parasites (filled symbols) and uninfected human RBCs (open symbols) by compounds 5 and 7. Representative experiments are shown. (B) Ratio of IC₅₀ values for inhibition of radiolabeled purine uptake via hENT1 compared with the IC₅₀ values for inhibition of uptake into RBC-free 3D7 strain P. falciparum parasites. IC₅₀ values used to calculate the ratios were the average of at least three separate experiments. Activity of hENT1 measured using [³H]adenosine uptake into uninfected RBC. IC₅₀ values for inhibition of [³H]adenosine uptake into RBC-free P. falciparum parasites are from Frame et al. (2015b). Note that the y-axis is a log scale.