title: Novel cycloartane triterpenoid from Cimicifuga foetida (Sheng ma) induces mitochondrial apoptosis via inhibiting Raf/MEK/ERK pathway and Akt phosphorylation in human breast carcinoma MCF-7 cells.
abstract: BACKGROUND
  Cycloartane triterpenoids exhibited anticancer effects. This study aims to identify any potential novel anticancer cycloartane triterpenoids from Cimicifuga foetida L. rhizome (Sheng ma) and the mode of actions.
  
  
  METHODS
  Cycloartane triterpenoids were isolated from the C. foetida rhizome by a series of column chromatography and identified by IR, MS and NMR. Their anticancer effects on several human cancer cell lines, MCF-7, HepG2, HepG2/ADM, HeLa, and PC3, and normal human mammary epithelial cells MCF10A were investigated by colony formation and MTT assays. Morphological analysis of apoptosis induction was performed by acridine orange/ethidium bromide dual-staining and Hoechst 33258 nuclear staining. The cell-cycle profile and annexin V staining were evaluated by flow cytometry. Apoptosis were investigated by measuring changes in mitochondrial membrane potential and analyzing expression of cell cycle- and apoptosis-related proteins in MCF-7 cells by Western blotting.
  
  
  RESULTS
  A novel cycloartane triterpenoid, 25-O-acetyl-7,8-didehydrocimigenol-3-O-β-d-(2-acetyl)xylopyranoside (ADHC-AXpn), together with the known 7,8-didehydrocimigenol-3-O-β-d-xylopyranoside (DHC-Xpn) were isolated. MCF-7 growth was significantly inhibited by ADHC-AXpn in a dose- and time-dependent manner (IC50: 27.81 µM at 48 h; P = 0.004 vs. control at 25 μM for 48 h treatment), and ADHC-AXpn was selectively cytotoxic for cancerous cells (MCF-7, HepG2/ADM, HepG2 and HELA cells) based on its higher IC50 values for normal cells MCF10A (IC50: 78.63 µM at 48 h) than for tumor cells. In MCF-7 cells, ADHC-AXpn induced G2/M cell cycle arrest by mediating cyclin-B1, and CDK1 and its phosphorylation; and induced apoptosis through the mitochondrial-mediated apoptotic pathway, with inhibition of Akt activation. As ADHC-AXpn suppressed phosphorylation of ERK1/2, Raf and Akt proteins in MCF-7 cells, its apoptotic effect might be associated with Raf/MEK/ERK signaling and Akt activation.
  
  
  CONCLUSIONS
  ADHC-AXpn significantly suppressed the growth of MCF-7 cells, induced mitochondrial apoptosis and cell-cycle arrest, and inhibited Raf/MEK/ERK signaling pathway and Akt phosphorylation.
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China ; State Key Laboratory of Chinese Medicine and Molecular Pharmacology, Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Chinese Medicine and Molecular Pharmacology, Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Bei-Bei
authors.initials: BB
authors.lastname: Liu
authors.affiliation: College of Pharmacy, Jinan University, Guangzhou, China.
authors.forename: Jian-Yang
authors.initials: JY
authors.lastname: Hu
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors.forename: Li-Jia
authors.initials: LJ
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Chinese Medicine and Molecular Pharmacology, Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Shun-Wan
authors.initials: SW
authors.lastname: Chan
authors.affiliation: State Key Laboratory of Chinese Medicine and Molecular Pharmacology, Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Chi-On
authors.initials: CO
authors.lastname: Chan
authors.affiliation: State Key Laboratory of Chinese Medicine and Molecular Pharmacology, Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Daniel K W
authors.initials: DK
authors.lastname: Mok
authors.affiliation: College of Pharmacy, Jinan University, Guangzhou, China.
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Zhang
authors.affiliation: College of Pharmacy, Jinan University, Guangzhou, China.
authors.forename: Wen-Cai
authors.initials: WC
authors.lastname: Ye
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China ; State Key Laboratory of Chinese Medicine and Molecular Pharmacology, Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Si-Bao
authors.initials: SB
authors.lastname: Chen