Fig. 4.

Intracellular Dox fluorescent intensity after applying different Dox formulations with or without P-gp inhibitor (verapamil). Bel7402 cells or Bel7402/5-FU MDR cells were treated with equivalent Dox concentration of 5 µg/ml for 4 h at 37 °C and then measured under flow cytometry. Data were expressed as mean ± SD (n = 3). **P < 0.01.