title: Cytotoxicity of Chinese motherwort (YiMuCao) aqueous ethanol extract is  non-apoptotic and estrogen receptor independent on human breast cancer cells.
abstract: BACKGROUND
  Motherwort has been used as medicinal herb for many years in both China and Europe. In particular, Chinese motherwort has been commonly used to treat disorders of mammary gland in Chinese traditional medicine (TCM). Chinese motherwort aqueous extract (MAE)was previously reported to have anti-cancer activity in breast cancer cells with low potency (IC50s in a range of 8-40 mg/mL). However, treatment of motherwort ethanol extract in vivo markedly suppressed the development of uterine adenomyosis and mammary cancers in mice. Therefore, anti-cancer activity of Chinese motherwort, especially in a form of ethanol extract, needs to be confirmed further at cellular level.
  
  
  METHODS
  Aerial part of Chinese motherwort (Leonurus japonicus Houtt) dry powder is extracted with 70% ethanol and the chemical components were characterized with HPLC finger print as well as mass spectrometry. Cytotoxicity of the motherwort aqueous ethanol extract (MAEE) was analyzed with MTT assay on ER negative MDA-MB-231 and ER positive MCF-7 human breast cancer cell lines. Hoechst 33342 staining and flow cytometry were used to verify whether the cell death induced by MAEE is apoptosis in nature. Cell cycle status of MAEE treated cells were analyzed with flow cytometry.
  
  
  RESULTS
  Our results showed that MAEE caused cell death in a dose-dependent and time-dependent fashion in both ER positive and negative breast cancer cells. Morphology, Hoechst 33342 staining and flow cytometry evidence all indicated the cell death is not in an apoptotic nature. Furthermore, low concentrations of MAEE caused cell cycle arrest at G2/M phase.
  
  
  CONCLUSIONS
  These data suggest that Chinese motherwort aqueous ethanol extract may effectively inhibit the proliferation of breast cancer cells through mechanisms of both cytotoxicity and cell cycle arrest. The cellular effects of MAEE are non-apoptotic and ER independent on breast cancer cells.
authors.affiliation: Department of General Dentistry, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Tao
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Guoyu
authors.initials: G
authors.lastname: Liu
authors.forename: Hang
authors.initials: H
authors.lastname: Yan
authors.forename: Xuexian
authors.initials: X
authors.lastname: Bu
authors.forename: Zhongjun
authors.initials: Z
authors.lastname: Ma
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.forename: Guomin
authors.initials: G
authors.lastname: Wang
authors.forename: William
authors.initials: W
authors.lastname: Jia