Kalanchoe tubiflora extract inhibits cell proliferation by affecting the mitotic apparatus
1 Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, 97004, Taiwan
2 Department of Molecular Biology and Human Genetics, Tzu Chi University, No. 701, Zhongyang Rd., Sec. 3, Hualien, 97004, Taiwan
3 Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan
4 Graduate Institute of Natural Products, Chang Gung University, Taoyuan, Taiwan
5 Department of Chemistry, National Dong-Hwa University, Hualien, Taiwan
6 School of Applied Chemistry, Chung Shan Medical University, No.110,Sec.1,Jianguo N.Road, Taichung City, 40201, Taiwan
7 Institute of NanoEngineering and MicroSystems, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan
8 Department of Medical Research, Buddhist Tzu-Chi General Hospital, Hualien, Taiwan
BMC Complementary and Alternative Medicine 2012, 12:149 doi:10.1186/1472-6882-12-149Published: 10 September 2012
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.
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.
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.
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.