[Synergistic effect of beta-elemene injection combined paclitaxel injection on human breast cancer MB-468 cells: an in vitro study].
OBJECTIVE
To observe the synergistic effect of beta-elemene Injection (betaI) combined Paclitaxel Injection (PI) on breast cancer MB-468 cells and to study possible mechanisms.


METHODS
Breast cancer MB-468 cells were treated with betaI (2.5, 5.0, 10.0, 20.0, 40.0, 80.0, 160.0, 320.0, and 640.0 microg/mL), PI (0.00100, 0.00200, 0.00400, 0.00800, 0.01600, 0.03125, 0.06250, 0.12500, and 0.25000 microg/mL), and betaI combined PI for 24 h and 48 h respectively. Cell proliferation was determined using SRB assay. Cell apoptosis and cell cycle phase distribution were detected using flow cytometry. The post-intervention expressions of cell cycle proteins [cyclin-dependent kinase (CDK1), cyclin-B1, P21(cip1), and P27(kip1)] were detected by Western blot.


RESULTS
Beta-elemene or paclitaxel inhibited the growth of MB-468 cell line. The IC50 and IC20 values treated with beta-elemene for 24 h were 34.20 and 52.59 microg/mL and for 48 h were 10.15 and 17.81 microg/mL respectively, while the IC50 values treated with paclitaxel for 24 h and 48 h were 2.449 and 1.698 microg/mL respectively. Beta-elemene (20 and 40 microg/mL respectively) and Paclitaxel (0.016 and 0.008 microg/mL respectively) synergistically inhibited cell proliferation of MB-468 cells, with Q value > 1.15. Beta-elemene alone (52.59 microg/mL) apparently decreased the expression of cyclin-B1 protein. The expression of cyclin-B1 protein in the combined group was also lower than that in the PI group (1.698 microg/mL). The expression of P27(kip1) was up-regulated when compared with that in the betaI group or the PI group.


CONCLUSIONS
Beta-elemene had synergistic effect with Paclitaxel, and its possible mechanism might be correlated with down-regulating the cell cycle protein cyclin-B1 expression and up-regulating the P27(kip1) expression.
Department of Oncology, Fourth People's Hospital of Wuxi City, Jiangsu 214062, China. cdy19761108@yahoo.com.cn
Dong-Yan
DY
Cai
Xiang
X
Gao
Xiao-Hong
XH
Wu
Ting-Ting
TT
Hong
D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D004357:Drug Synergism; D005260:Female; D006801:Humans; D017239:Paclitaxel / Q000008:administration & dosage / Q000494:pharmacology*; D012717:Sesquiterpenes / Q000008:administration & dosage / Q000494:pharmacology*
D000972:Antineoplastic Agents, Phytogenic; D018797:Cell Cycle Proteins; D012717:Sesquiterpenes; C445979:beta-elemene; D017239:Paclitaxel