Abstract: AimTo determine the effects of azide methyl anthraquinone derivative (AMAD) on growth inhibition and inducing apoptosis of multidrug resistant (MDR) KBv200 cells and parental drug-sensitive KB cells. MethodsCytotoxicity was determined by tetrazolium (MTT) assay. Reactive oxygen species (ROS) levels and mitochondrial membrane potential (ΔΨ_m) in cells were labeled with DCFH-DA and DiOC₆ and tested by flow cytometry. Annexin V stain and DNA ladder were used to examine the apoptosis of KB and KBv200 cells induced by AMAD. ResultsAMAD was shown to inhibit the growth of KB and KBv200 cells significantly in a concentration-dependent manner, with mean IC₅₀ of 0.36 and 0.45 μmol·L^-1, respectively. The generation of ROS increased obviously after the cells were treated with AMAD for 12 h, up to the peak in 24 h, meanwhile the levels of ΔΨ_m were time-dependently decreased. DNA fragmentation appeared on the agarose gel. Annexin V stain showed AMAD induced apoptosis of KB and KBv200 cells also in a concentration-dependent manner. ConclusionAMAD showed inhibitory effect on both MDR KBv200 cells and parental drug-sensitive KB cells. The mechanism of action was associated with the increase of the cellular ROS level and the decrease of the mitochondrial membrane potential induced by AMAD, which result in cell apoptosis.