Article

Phytoestrogens and mycoestrogens bind to the rat uterine estrogen receptor.

Division of Genetic and Reproductive Toxicology, Jefferson Laboratories, National Center for Toxicological Research, Jefferson, AR 72079, USA.
Journal of Nutrition (impact factor: 3.92). 05/2002; 132(4):658-64. pp.658-64
Source: PubMed

ABSTRACT Consumption of phytoestrogens and mycoestrogens in food products or as dietary supplements is of interest because of both the potential beneficial and adverse effects of these compounds in estrogen-responsive target tissues. Although the hazards of exposure to potent estrogens such as diethylstilbestrol in developing male and female reproductive tracts are well characterized, less is known about the effects of weaker estrogens including phytoestrogens. With some exceptions, ligand binding to the estrogen receptor (ER) predicts uterotrophic activity. Using a well-established and rigorously validated ER-ligand binding assay, we assessed the relative binding affinity (RBA) for 46 chemicals from several chemical structure classes of potential phytoestrogens and mycoestrogens. Although none of the test compounds bound to ER with the affinity of the standard, 17beta-estradiol (E(2)), ER binding was found among all classes of chemical structures (flavones, isoflavones, flavanones, coumarins, chalcones and mycoestrogens). Estrogen receptor relative binding affinities were distributed across a wide range (from approximately 43 to 0.00008; E(2) = 100). These data can be utilized before animal testing to rank order estimates of the potential for in vivo estrogenic activity of a wide range of untested plant chemicals (as well as other chemicals) based on ER binding.

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Keywords

46 chemicals
 
adverse effects
 
chemical structure classes
 
chemical structures
 
diethylstilbestrol
 
estrogen receptor
 
Estrogen receptor relative binding affinities
 
estrogen-responsive target tissues
 
female reproductive tracts
 
food products
 
ligand binding
 
potential beneficial
 
potential phytoestrogens
 
rank order estimates
 
relative binding affinity
 
rigorously validated ER-ligand binding assay
 
test compounds
 
untested plant chemicals
 
uterotrophic activity
 
vivo estrogenic activity