Aim: To investigate the possible mechanism of 20(S)-protopanaxadiol[20(S)-PPD] which could induce apoptosis of breast cancer MCF-7 cells via regulating miRNA-19b. Methods: MCF-7 cells were treated with 30,40,50,60,70,80 μmol/L 20( S)-PPD for 48 h and the cell viability was detected by MTT method. MCF-7 cells were treated with 30,50,80 μmol/L 20( S)-PPD for 48 h,the expression level of miRNA-19b was detected by real-time PCR,and DNMT activity assay kit was used to detect the DNMT activity. MCF-7 cells were d...