title: Cytotoxicity enhancement in MDA-MB-231 cells by the combination treatment of tetrahydropalmatine and berberine derived from Corydalis yanhusuo W. T. Wang.
abstract: OBJECTIVE
  Our previous works have demonstrated that Chinese herb medicine yanhusuo (Corydalis yanhusuo W. T. Wang) has strong anti-cancer proliferation effect in MDA-MB-231 cells. The goal of this study was to find out the synergic cytotoxicity effect of three natural compounds, tetrahydropalmatine (THP), berberine (Ber), and dehydrocorydaline (DHC), isolated from C. yanhusuo W. T. Wang.
  
  
  METHODS
  The IC50 of THP Ber and DHC in single use, as well as in combination use at fixed ratios and doses was measured by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. Isobologram, combination index and modified coefficient of drug interaction (CDI) methods were used for evaluation the combination effects of THF! Ber, and DHC in different ratio and concentration.
  
  
  RESULTS
  The results indicated that the combination of THP and Ber shown the strongest anti-cancer cell proliferation effect at the ratio of 2:3 (Ber: THF the average CDI value was 0.5795). DHC and THP have additive cytotoxicity in MDA-MB-231 cells. However, there wasn't any synergistic effect between Ber and DHC, and it even exhibited antagonistic effect when the percentage of DHC was >50%.
  
  
  CONCLUSIONS
  Our findings suggested that the combination of THP and Ber might be beneficial for anti-proliferation of MDA-MB-231 breast cancer cells through a significant synergy effect.
authors.affiliation: Zhejiang Chinese Medical University, Binjiang, Hangzhou, Zhejiang, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Zhejiang Chinese Medical University, Binjiang, Hangzhou, Zhejiang, China.
authors.forename: Jian-Li
authors.initials: JL
authors.lastname: Gao
authors.affiliation: Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Ji
authors.affiliation: Zhejiang Chinese Medical University, Binjiang, Hangzhou, Zhejiang, China.
authors.forename: Min
authors.initials: M
authors.lastname: Gao
authors.affiliation: Zhejiang Chinese Medical University, Binjiang, Hangzhou, Zhejiang, China.
authors.forename: Qiao-Shan
authors.initials: QS
authors.lastname: Yin
authors.affiliation: Zhejiang Chinese Medical University, Binjiang, Hangzhou, Zhejiang, China.
authors.forename: Qiao-Li
authors.initials: QL
authors.lastname: Qiu
authors.affiliation: Zhejiang Chinese Medical University, Binjiang, Hangzhou, Zhejiang, China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Wang
authors.affiliation: Zhejiang Chinese Medical University, Binjiang, Hangzhou, Zhejiang, China.
authors.forename: Shu-Zhan
authors.initials: SZ
authors.lastname: Chen
authors.affiliation: Zhejiang Chinese Medical University, Binjiang, Hangzhou, Zhejiang, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Xu
authors.affiliation: Zhejiang Chinese Medical University, Binjiang, Hangzhou, Zhejiang, China.
authors.forename: Ren-Shang
authors.initials: RS
authors.lastname: Liang
authors.affiliation: Zhejiang Chinese Medical University, Binjiang, Hangzhou, Zhejiang, China.
authors.forename: Yan-Zi
authors.initials: YZ
authors.lastname: Cai
authors.affiliation: Zhejiang Chinese Medical University, Binjiang, Hangzhou, Zhejiang, China.
authors.forename: Xia-Fei
authors.initials: XF
authors.lastname: Wang
keywords: Coefficient of drug interaction; Corydalis Yanhusuo W. T. Wang; combination effect; natural products