Androgen receptor expression in the rat prostate is down-regulated by dietary phytoestrogens

Trent D Lund¹ , Daniel J Munson¹ , Herman Adlercreutz² , Robert J Handa¹ and Edwin D Lephart³

¹Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA

²Institute for Preventive Medicine, Nutrition, and Cancer Folkhälsan Research Center, and Division of Clinical Chemistry, Biomedicum, University of Helsinki, Finland

³The Neuroscience Center and Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, USA

author email corresponding author email

Reproductive Biology and Endocrinology 2004, 2:5doi:10.1186/1477-7827-2-5


Published:	16 January 2004

Abstract

Background

It is well established that the growth of the prostate gland is a hormone-dependent phenomenon involving both androgenic and estrogenic control. Proliferation of prostate cells is, at least in part, under control of estrogen receptor beta (ER-beta). Phytoestrogens bind ER-beta with high affinity and therefore may have antiproliferative effects in the prostate.

Methods

The prostates of male Long-Evans rats fed a diet high in phytoestrogens (Phyto-600) or very low levels of phytoestrogens (Phyto-free) were analyzed to determine the impact of dietary phytoestrogens on prostate weight and androgen receptor (AR) expression in the prostate.

Results

Dietary phytoestrogens significantly decreased post-pubertal prostate weight gain in Phyto-600 vs Phyto-free fed males. Additionally, dietary phytoestrogens (Phyto-600) decreased AR expression in the prostate as determined by in situ hybridization.

Conclusions

Soy phytoestrogens, present in diet, alter prostate growth presumably by binding ER-beta and subsequently reducing AR expression within the prostate.