Skip Navigation


Carcinogenesis Advance Access originally published online on May 18, 2006
Carcinogenesis 2006 27(10):1970-1979; doi:10.1093/carcin/bgl028
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
27/10/1970    most recent
bgl028v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (2)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Manjanatha, M.
Right arrow Articles by Aidoo, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Manjanatha, M.
Right arrow Articles by Aidoo, A.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Published by Oxford University Press 2006

Dietary effects of soy isoflavones daidzein and genistein on 7,12-dimethylbenz[a]anthracene-induced mammary mutagenesis and carcinogenesis in ovariectomized Big Blue transgenic rats

Mugimane Manjanatha*, Sharon Shelton, Michelle Bishop, Lascelles Lyn-Cook and Anane Aidoo

U.S. FDA National Center for Toxicological Research, Genetic Toxicology Rockville, MD 20857, USA

*To whom correspondence should be addressed. Email: mmanjanatha{at}nctr.fda.gov, mugimane{at}yahoo.com

The major constituents of isoflavones daidzein (DZ) and genistein (GE) interact with the and estrogen receptors in several tissues including mammary tissues. In this study, we used ovariectomy (OVX) to model menopause and determined the effects of DZ, GE or 17ß-estradiol (E2) exposures on chemically induced mutagenesis and carcinogenesis in the mammary glands of female Big Blue transgenic rats. The rats were fed control diet containing the isoflavones and E2 and treated with a single oral dose of 7,12-dimethylbenz[a]anthracene (DMBA) at PND50. Animals were euthanized at 16 or 20 weeks post-carcinogen treatment to assess mutant frequencies (MFs) and histopathological parameters, respectively. The isoflavones or E2 supplementation alone resulted in the lac I MFs that were not significantly different from the MFs measured in rats fed the control diet alone. DMBA exposure, however, induced significant increases in the lac I MFs in the mammary tissues of both OVX and INT rats and Hprt MFs in spleen lymphocytes (P < 0.01). In general, feeding the isoflavones or E2 did not cause any significant changes in DMBA-induced mutagenicity in the mammary tissues. However, feeding the isoflavone mixture (daidzein + genistein; DZG) resulted in a significant reduction in the DMBA-induced lac I MFs (P < 0.05). Cell proliferation as measured by PCNA immunohistochemistry was increased in both OVX and INT rats exposed to DMBA as compared with rats fed control diet (P < 0.05). Mammary histology indicated that hyperplasia was induced in most of the treatment groups including control. Although DMBA did not induce mammary tumors in the OVX rats, adenoma and adenocarcinoma were detected in the mammary glands of INT rats.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.