nonylphenol (np) is a well-known compound as having the potential to mimic the natural hormone 17β-estradiol (e2) and disrupt the endocrine system in a wide range of organisms. however, the ability of different isomers of this compound is different in exerting estrogenic effects. the objectives of this study were to estimate the effects of a straight side-chain np isomer (4-n-np) on the vitello...

This study reports on the development and application of a fish-specific estrogen-responsive reporter gene assay. The assay is based on the rainbow trout (Oncorhynchus mykiss) gonad cell line RTG-2 in which an acute estrogenic response is created by cotransfecting cultures with an expression vector containing rainbow trout estrogen receptor a complementary DNA (rtERalpha cDNA) in the presence o...

Human activity has spread trace amounts of chemically stable endocrine-disrupting pollutants throughout the biosphere. These compounds have generated a background level of estrogenic activity that needs to be assessed. Fish are adequate sentinels for feminization effects as male specimens are more sensitive than humans to exogenous estrogenic compounds. High mountain lakes, the most distant env...

in the present study, plumbago zeylanica linn. (plumbaginaceae) , one of the folk medicinal plants commonly used as antifertility agent was evaluated for its antifertility effect. five successive solvent extracts, petroleum ether, chloroform, acetone, ethanol and water extracts, of the stems of p. zeylanica were studied on estrous cycle at two dose levels, 200 and 400 mg/kg respectively.   of t...

Concern that the reproductive health of humans is being affected by exposure to xenoestrogens has led to the development of various in vitro and in vivo screening assays for the identification of suspected xenoestrogens. However, the estrogenic activity of a chemical determined in vitro may not necessarily predict its activity in vivo if the chemical is metabolized during the assay and/or in vi...

Breast cancer is the most frequently diagnosed cancer in women and systematic therapy is an essential component of disease. Hormonal therapy, cytotoxic chemotherapy and the more recently introduced biological therapies are routinely employed in the vast majority of patients. Several pharmaceuticals that affect the estrogenic pathways have been studied as chemopreventive agents. Tamoxifen is an ...

We have previously reported that royal jelly (RJ) from honeybees (Apis mellifera) has weak estrogenic activity mediated by interaction with estrogen receptors that leads to changes in gene expression and cell proliferation. In this study, we isolated four compounds from RJ that exhibit estrogenic activity as evaluated by a ligand-binding assay for the estrogen receptor (ER) beta. These compound...

The genus Cyclopia, an indigenous South African fynbos plant used to prepare honeybush tea, contains phytoestrogenic compounds. An extract from C. subternata, SM6Met, displays three desirable estrogenic attributes for future development of a phytoestrogenic nutraceutical, namely, ERα antagonism, ERβ agonism, and also antagonism of E2-induced breast cancer cell proliferation. Activity-guided fra...

The increased cancer risk associated with hormone therapies has encouraged many women to seek non-hormonal alternatives including botanical supplements such as hops (Humulus lupulus) and licorice (Glycyrrhiza spec.) to manage menopausal symptoms. Previous studies have shown estrogenic properties for hops, likely due to the presence of 8-prenylnarigenin, and chemopreventive effects mainly attrib...