Effect of emodin combined with various amount of rhodamine 123 or verapamil on inhibition of P-gp.

<p>K562/ADM cells were incubated with emodin (0.25–20 μM), together with 1, 3, 10 μM of rhodamine 123, respectively (A); The <i>K</i>_<i>i</i> of emodin was calculated and plotted against the concentrations of rhodamine 123 (B). K562/ADM cells were incubated with emodin (0.25–20 μM) with 0.5, 1, 2 μM of verapamil and 1 μM of rhodamine 123 (C). The calculated values of <i>K</i>_<i>i</i> for emodin were plotted against the concentrations of verapamil (D). Data were represented as the mean ± S.D of three independent experiments.