Planta Med 2006; 72(13): 1200-1206
DOI: 10.1055/s-2006-947225
Original Paper
Pharmacology
© Georg Thieme Verlag KG Stuttgart · New York

Actein and a Fraction of Black Cohosh Potentiate Antiproliferative Effects of Chemotherapy Agents on Human Breast Cancer Cells

Linda Saxe Einbond1 , Masahito Shimizu1 , Paiboon Nuntanakorn2 , Colette Seter1 , Rong Cheng1 , Bei Jiang1 , Fredi Kronenberg1 , Edward J. Kennelly2 , I. Bernard Weinstein1
  • 1Columbia University College of Physicians and Surgeons, New York, NY, USA
  • 2Lehman College in the Graduate Center, The City University of New York, Bronx, NY, USA
Further Information

Publication History

Received: August 1, 2005

Accepted: June 20, 2006

Publication Date:
20 September 2006 (online)

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Abstract

The purpose of this study was to determine whether the triterpene glycosides present in black cohosh enhance the growth inhibitory effects of specific breast cancer chemotherapy agents. Black cohosh roots and rhizomes were extracted with methanol (MeOH)/water (H2O) and fractionated by solvent-solvent partitioning to yield three fractions: hexane, ethyl acetate (EtOAc) and water. The EtOAc fraction is enriched in triterpene glycosides, including the compound actein. Actein and the EtOAc fraction were then tested, alone and in combination with chemotherapy agents, for growth inhibition of the ER- Her2 overexpressing breast cancer cell line MDA-MB-453. We found that actein exerted a synergistic effect on growth inhibition when combined with doxorubicin or 5-flourouracil. Synergy was also obtained when the EtOAc fraction was combined with doxorubicin. Actein increased the percent of cells in the G1 phase of the cell cycle and had a similar effect when combined with 5-flourouracil or doxorubucin. Actein enhanced the induction of apoptosis by paclitaxel, 5-flourouracil or doxorubicin. Our results indicate that relatively low concentrations of actein or the EtOAc fraction of black cohosh can cause synergistic inhibition of human breast cancer cell proliferation when combined with different classes of chemotherapy agents.

Abbreviations

CI:Combination Index

DOX:Doxorubicin

DMEM:Dulbecco's Modified Eagle's medium

FBS:Fetal Bovine Serum

5-FU:5-Fluorouracil

TAX:Paclitaxel