title: Kalanchoe tubiflora extract inhibits cell proliferation by affecting the mitotic apparatus.
abstract: BACKGROUND
  Kalanchoe tubiflora (KT) is a succulent plant native to Madagascar, and is commonly used as a medicinal agent in Southern Brazil. The underlying mechanisms of tumor suppression are largely unexplored.
  
  
  METHODS
  Cell viability and wound-healing were analyzed by MTT assay and scratch assay respectively. Cell cycle profiles were analyzed by FACS. Mitotic defects were analyzed by indirect immunofluoresence images.
  
  
  RESULTS
  An n-Butanol-soluble fraction of KT (KT-NB) was able to inhibit cell proliferation. After a 48 h treatment with 6.75 μg/ml of KT, the cell viability was less than 50% of controls, and was further reduced to less than 10% at higher concentrations. KT-NB also induced an accumulation of cells in the G2/M phase of the cell cycle as well as an increased level of cells in the subG1 phase. Instead of disrupting the microtubule network of interphase cells, KT-NB reduced cell viability by inducing multipolar spindles and defects in chromosome alignment. KT-NB inhibits cell proliferation and reduces cell viability by two mechanisms that are exclusively involved with cell division: first by inducing multipolarity; second by disrupting chromosome alignment during metaphase.
  
  
  CONCLUSIONS
  KT-NB reduced cell viability by exclusively affecting formation of the proper structure of the mitotic apparatus. This is the main idea of the new generation of anti-mitotic agents. All together, KT-NB has sufficient potential to warrant further investigation as a potential new anticancer agent candidate.
authors.affiliation: Department of Molecular Biology and Human Genetics, Tzu Chi University, No. 701, Zhongyang Rd., Sec, 3, Hualien, 97004, Taiwan.
authors.forename: Yi-Jen
authors.initials: YJ
authors.lastname: Hsieh
authors.forename: Ming-Yeh
authors.initials: MY
authors.lastname: Yang
authors.forename: Yann-Lii
authors.initials: YL
authors.lastname: Leu
authors.forename: Chinpiao
authors.initials: C
authors.lastname: Chen
authors.forename: Chin-Fung
authors.initials: CF
authors.lastname: Wan
authors.forename: Meng-Ya
authors.initials: MY
authors.lastname: Chang
authors.forename: Chih-Jui
authors.initials: CJ
authors.lastname: Chang
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D031962:Kalanchoe / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D008941:Spindle Apparatus / Q000187:drug effects*
chemical_list: D000970:Antineoplastic Agents; D010936:Plant Extracts