title: Platycodin D from Platycodonis Radix enhances the anti-proliferative effects of doxorubicin on breast cancer MCF-7 and MDA-MB-231 cells.
abstract: BACKGROUND
  It has been demonstrated that platycodin D (PD) exhibits anti-cancer activities. This study aims to investigate the anti-proliferative effects of the combination of PD and doxorubicin (DOX) on human breast cancer cells (MCF-7 and MDA-MB-231 cells).
  
  
  METHODS
  The anti-proliferative effects of different dosages of PD, DOX, and PD + DOX on MCF-7 and MDA-MB-231 cells were determined by the MTT assay. The 10 μM PD, 5 μM DOX, and 10 μM PD + 5 μM DOX induced-protein expression of apoptosis-related molecules on MCF-7 and MDA-MB-231 cells were detected by western blot. The 10 μM PD, 5 μM DOX and 10 μM PD + 5 μM DOX-induced mitochondrial membrane potential changes on MCF-7 and MDA-MB-231 cells were stained with JC-1 before visual determination. The intracellular accumulations of DOX, induced by 10 μM PD, 5 μM DOX and 10 μM PD + 5 μM DOX, were detected by flow cytometry.
  
  
  RESULTS
  PD enhanced anti-cancer activities of DOX were observed in both MCF-7 and MDA-MB-231 cell lines. Compared with mono treatment, the combined treatment increased the protein expression of cleaved poly (ADP-ribose) polymerase and decreased the mitochondrial membrane potential. The combined treatment with PD did not obviously increase the accumulation of DOX in MCF-7 cells (1.66 ± 0.13 in DOX-treated group, and 1.69 ± 0.06 in PD + DOX-treated group, P = 0.76), but it significantly increased the accumulation of DOX in MDA-MB-231 cells (1.76 ± 0.17 in DOX-treated group, 2.09 ± 0.02 in PD + DOX-treated group, P = 0.027).
  
  
  CONCLUSIONS
  The combined treatment of DOX and PD exhibited stronger anti-proliferative effects on MCF-7 and MDA-MB-231 cells than DOX and PD treatment did.
authors: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors: Zheng-Hai
authors: ZH
authors: Tang
authors: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors: Ting
authors: T
authors: Li
authors: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors: Hong-Wei
authors: HW
authors: Gao
authors: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors: Wen
authors: W
authors: Sun
authors: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors: Xiu-Ping
authors: XP
authors: Chen
authors: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors: Yi-Tao
authors: YT
authors: Wang
authors: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors: Jin-Jian
authors: JJ
authors: Lu