Figure 2.

Inhibition of calcein-AM transport. BacMam P-gp baculovirus-transduced HeLa cells were assayed for calcein-AM transport (A) in the presence of selected derivatives at 10 μM and (B) in the presence of increasing concentrations of 11, 12, 14, and 28. (A) Representative histograms show low, moderate, and high P-gp inhibitory activity of selected thiazole derivatives. Tariquidar (1 μM), a known inhibitor of P-gp, was used for comparison. The values shown are the average of two independent experiments each done in triplicate. (B) Concentration-dependent inhibition of calcein-AM efflux by selected derivatives was studied. The average values from two independent experiments each done in triplicate were plotted and the IC₅₀ values for compounds 11 (filled squares), 12 (filled diamonds), 14 (filled triangles), and 28 (filled circles) are 2.5, 6.5, 16, and 1 μM, respectively.