Effects of S-equol and natural S-equol supplement (SE5-OH) on the growth of MCF-7 in vitro and as tumors implanted into ovariectomized athymic mice

Atsuko Onoda, Tomomi Ueno, Shigeto Uchiyama, Shin ichi Hayashi, Kiyoko Kato, Norio Wake

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

Hormone replacement therapy (HRT) for treatment of menopausal symptoms is controversial because of reported breast cancer resulting from estrogen treatment and consequent estrogenic stimulation. S-equol, a natural metabolite of the soy isoflavone daidzein produced by intestinal bacteria, has been shown to ameliorate menopausal symptoms, with relatively low concomitant estrogenic receptor stimulation. Although synthesis of equol produces the racemate, the S-isomer may be produced in commercial amounts by bacterial fermentation of soy germ, during the production of the supplement SE5-OH. This study aims to investigate the effects of S-equol and SE5-OH on the growth of MCF-7 in vitro and in vivo. In vitro, purified S-equol, and the isoflavonoid mixture present in SE5-OH stimulated estrogenic transcriptional activity and proliferation of MCF-7-E10 cells, similar to that observed for genistein (another soy isoflavone), but at concentrations from 10 4-fold to 10 6-fold higher than seen with 17β-estradiol (E2).Ovariectomized (OVX) mice implanted with MCF-7-E10 cells were fed diets containing 250 or 500. ppm of purified S-equol, isoflavonoid mixture, or genistein. There were no significant differences in tumor growth between the treatment groups and control group. These results suggest that S-equol and natural S-equol in the supplement (SE5-OH), do not promote the progression of breast cancer.

Original languageEnglish
Pages (from-to)2279-2284
Number of pages6
JournalFood and Chemical Toxicology
Volume49
Issue number9
DOIs
Publication statusPublished - Sep 2011

All Science Journal Classification (ASJC) codes

  • Food Science
  • Toxicology

Fingerprint Dive into the research topics of 'Effects of S-equol and natural S-equol supplement (SE5-OH) on the growth of MCF-7 in vitro and as tumors implanted into ovariectomized athymic mice'. Together they form a unique fingerprint.

  • Cite this