scholarly journals DIFFERENTIAL ESTROGENIC ACTIVITY OF PUERARIA MIRIFICA LEAVES DETERMINED BY YEAST ESTROGEN SCREEN HARBORED HUMAN ESTROGEN RECEPTOR-A AND-B

2012 ◽  
Vol 10 (2) ◽  
pp. 46-1
Author(s):  
Binar Asrining Dhiani ◽  
Jutarmas Jungsukcharoen ◽  
Chuenchit Boonchird ◽  
Wichai Cherdshewasart
Keyword(s):  
Estrogen Receptor ◽  
Estrogenic Activity ◽  
Pueraria Mirifica ◽  
Yeast Estrogen Screen ◽  
Human Estrogen Receptor

Phytoestrogens Induce Differential Estrogen Receptor Alpha- or Beta-Mediated Responses in Transfected Breast Cancer Cells

2005 ◽  
Vol 230 (8) ◽  
pp. 558-568 ◽  
Author(s):  
D. M. Harris ◽  
E. Besselink ◽  
S. M. Henning ◽  
V. L. W. Go ◽  
D. Heber
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Estrogen Receptor Alpha ◽  
Estrogenic Activity ◽  
Mammary Adenocarcinoma ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Human Estrogen Receptor ◽  
17Β Estradiol ◽  
Risk Of Cancer

Increased intake of phytoestrogens may be associated with a lower risk of cancer in the breast and several other sites, although there is controversy surrounding this activity. One of the mechanisms proposed to explain the activity of phytoestrogens is their ability to bind and activate human estrogen receptor a (ERα) and human estrogen receptor β (ERβ). Nine phytoestrogens were tested for their ability to transactivate ERα or ERβ at a range of doses. Mammary adenocarcinoma (MCF-7) cells were co-transfected with either ERα or ERβ, and an estrogen-response element was linked to a luciferase reporter gene. Dose-dependent responses were compared with the endogenous ligand 17β-estradiol. Purified genistein, daidzein, apigenin, and coumestrol showed differential and robust transactivation of ERα- and ERβ-induced transcription, with an up to 100-fold stronger activation of ERβ. Equol, naringenin, and kaempferol were weaker agonists. When activity was evaluated against a background of 0.5 nM 17β-estradiol, the addition of genistein, daidzein, and resveratrol superstimulated the system, while kaempferol and quercetin were antagonists at the highest doses. This transfection assay provides an excellent model to evaluate the activation of ERα and ERβ by different phytoestrogens in a breast cancer context and can be used as a screening bioassay tool to evaluate the estrogenic activity of extracts of herbs and foods.

Assessment of the Estrogenic Activity of Flue Gases from Burning Processes by Means of the Yeast Based Human Estrogen Receptor (hER) Bioassay

2002 ◽  
Vol 23 (3) ◽  
pp. 287-291 ◽  
Author(s):  
W. Muthumbi ◽  
P. De Boever ◽  
I. D'Haese ◽  
W. D'Hooge ◽  
E. M Top ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Estrogenic Activity ◽  
Flue Gases ◽  
Human Estrogen Receptor

scholarly journals Heterologous Expression of Arabidopsis UDP-Glucosyltransferases in Saccharomyces cerevisiae for Production of Zearalenone-4-O-Glucoside

2006 ◽  
Vol 72 (6) ◽  
pp. 4404-4410 ◽  
Author(s):  
Brigitte Poppenberger ◽  
Franz Berthiller ◽  
Herwig Bachmann ◽  
Doris Lucyshyn ◽  
Clemens Peterbauer ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Arabidopsis Thaliana ◽  
Estrogen Receptor ◽  
Estrogenic Activity ◽  
Infected Plant ◽  
Pathogenic Fungi ◽  
Plant Pathogenic Fungi ◽  
Genes Encoding ◽  
Human Estrogen Receptor ◽  
Plant Genes

ABSTRACT Zearalenone, a secondary metabolite produced by several plant-pathogenic fungi of the genus Fusarium, has high estrogenic activity in vertebrates. We developed a Saccharomyces cerevisiae bioassay strain that we used to identify plant genes encoding UDP-glucosyltransferases that can convert zearalenone into zearalenone-4-O-glucoside (ZON-4-O-Glc). Attachment of the glucose moiety to zearalenone prevented the interaction of the mycotoxin with the human estrogen receptor. We found that two of six clustered, similar UGT73C genes of Arabidopsis thaliana encode glucosyltransferases that can inactivate zearalenone in the yeast bioassay. The formation of glucose conjugates seems to be an important plant mechanism for coping with zearalenone but may result in significant amounts of “masked” zearalenone in Fusarium-infected plant products. Due to the unavailability of an analytical standard, the ZON-4-O-Glc is not measured in routine analytical procedures, even though it can be converted back to active zearalenone in the digestive tracts of animals. Zearalenone added to yeast transformed with UGT73C6 was converted rapidly and efficiently to ZON-4-O-Glc, suggesting that the cloned UDP-glucosyltransferase could be used to produce reference glucosides of zearalenone and its derivatives.

Estrogenic activity of dicofol with the human estrogen receptor: Isomer- and enantiomer-specific implications

Chemosphere ◽  
2006 ◽  
Vol 64 (1) ◽  
pp. 174-177 ◽  
Author(s):  
Paul F. Hoekstra ◽  
B. Kent Burnison ◽  
A. Wayne Garrison ◽  
Tannis Neheli ◽  
Derek C.G. Muir
Keyword(s):  
Estrogen Receptor ◽  
Estrogenic Activity ◽  
Human Estrogen Receptor
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