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Journal ArticleDOI

Estrogenic Activities of 517 Chemicals by Yeast Two-Hybrid Assay

TL;DR: A simple and rapid screening method using the yeast two-hybrid system based on the ligand-dependent interaction of nuclear hormone receptors with coactivators to test the estrogenic activity of chemicals.
Abstract: One of the urgent tasks in understanding endocrine disruptors (EDs) is to compile a list of suspected substances among the huge number of chemicals by using the screening test method. We developed a simple and rapid screening method using the yeast two-hybrid system based on the ligand-dependent interaction of nuclear hormone receptors with coactivators. To date, we have tested the estrogenic activity of more than 500 chemicals including natural substances, medicines, pesticides, and industrial chemicals. 64 compounds were evaluated as positive, and most of these demonstrated a common structure; phenol with a hydrophobic moiety at the para-position without bulky groups at the ortho-position. These results are expected to facilitate further risk assessment of chemicals.

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Journal ArticleDOI
TL;DR: A fast and reliable method was developed for simultaneous trace determination of nine odorous and estrogenic chloro- and bromo-phenolic compounds in water samples using solid-phase extraction coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS).
Abstract: A fast and reliable method was developed for simultaneous trace determination of nine odorous and estrogenic chloro- and bromo-phenolic compounds (CPs and BPs) in water samples using solid-phase extraction (SPE) coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS). For sample preparation, the extraction efficiencies of two widely applied cartridges Oasis HLB and Sep-Pak C18 were compared, and the Oasis HLB cartridge showed much better extraction performance; pH of water sample also plays important role on extraction, and pH = 2–3 was found to be most appropriate. For separation of the target compounds, small addition of ammonium hydroxide can obviously improve the detection sensitivity, and the optimized addition concentration was determined as 0.2%. The developed efficient method was validated and showed excellent linearity (R 2 > 0.995), low limit of detection (LOD, 1.9–6.2 ng/L), and good recovery efficiencies of 57–95% in surface and tap water with low relative standard deviation (RSD, 1.3–17.4%). The developed method was finally applied to one tap and one surface water samples and most of these nine targets were detected, but all of them were below their odor thresholds, and their estrogen equivalent (EEQ) were also very low.

29 citations


Cites methods from "Estrogenic Activities of 517 Chemic..."

  • ...The MS/MS experimental conditions were – not available; [1] Olsen et al. 2002; [2] Nishihara et al. 2000; [3] Schummer et al. 2009 optimized by injection of both individual standard solution and a mixed solution of all the target compounds, and the optimized parameters are shown in Table 2....

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Journal ArticleDOI
TL;DR: In this article, the authors evaluated the estrogenic activity of phytoestrogens (such as daidzin, genistin, daidzein, genistein, coumestrol and equol) and the feed diets for experimental animals, such as fish, amphibians and reptiles, towards human estrogen receptors α (hER-α) and β (hERG-β).
Abstract: Phytoestrogens, such as daidzein and genistein in plants are suspected as endocrine-disrupting chemicals (EDCs), because their chemical structures are similar to natural or synthetic estrogens, and have estrogenic activity in vitro and in vivo. An EDC study was carried out on the diets of various animals in vivo. However, many of these diets include phytoestrogens and may already possess estrogenic activity. In this study, we evaluated the estrogenic activity of phytoestrogens (such as daidzin, genistin, daidzein, genistein, coumestrol and equol) and the feed diets for experimental animals, such as fish, amphibians and reptiles, towards human estrogen receptors α (hER-α) and β (hER-β), and the genistein and daidzein content in these diets from HPLC analysis. Coumestrol showed the highest estrogenic activity for hER-α and -β in the -S9 test. Equol showed the highest estrogenic activity for hER-α in the +S9 test. The estrogenic activities of coumestrol, equol and genistein were approximately one hundred to two thousand times higher than that of daidzein. Many of these compounds showed higher compatibility with hER-β than with hER-α. A diet for fish from soybean was indicated to contain the highest amounts of genistein and daidzein. Moreover, this fish diet had the highest estrogenic activity for hER-α and -β. The estrogenic activity was found with hydrolysis by β-glucuronidase, showing higher compatibility with hER-β than with hER-α. In addition, correlation between the contents of genistein and estrogenic activities in the diets was found, with the exception of part of the diet. Therefore, this indicates that the genistein content contributes to the estrogenic activity of the diets. These results suggest that in vivo estrogenic activity might be caused by the diet provided to an experimental animal, indicating the necessity for more careful selection of the feeding diet and measurement of estrogenic substances when performing an in vivo screening assay for EDCs.

29 citations

Journal ArticleDOI
TL;DR: The risk for the three DWTPs studied to produce drinking water with significant level of estrogenic substances appears to be low, and among the 10 chlorination by-products tested, only 2-chlorophenol was found to be weakly estrogenic at concentrations up to 1mg/L.

29 citations

Journal ArticleDOI
TL;DR: Results differ from previous studies showing NP as being more lethal to nematodes than BPA, but there was a slight increase in the attainment level of nematode treated with 1 μM NP.
Abstract: We observed and evaluated the feeding behavior of the free-living nematode Caenorhabditis elegans (C. elegans) after exposure to bisphenol A (BPA) and nonylphenol (NP). Exposed organisms were transferred to chemical-free culture medium and their attainment levels (the number of worms reaching the food source divided by the total number of worms on the Petri plate) were recorded after 2, 4, 6, 8, and 24 hr. Results showed a significant decrease in the attainment level of worms exposed to 10 μM and 0.1 μM BPA. However, there was a slight increase in the attainment level of nematodes treated with 1 μM NP. These results differ from previous studies showing NP as being more lethal to nematodes than BPA.

28 citations

Journal ArticleDOI
TL;DR: An effective method based on automated online headspace solid phase microextraction (HS-SPME) followed by on-fiber derivatization coupled with gas chromatography-mass spectrometry (GC-MS) for simultaneous determination of eleven estrogenic and odorous chloro- and bromo-phenolic compounds was developed.
Abstract: An effective method based on automated online headspace solid-phase microextraction (HS-SPME) followed by on-fiber derivatization coupled with gas chromatography-mass spectrometry (GC-MS) for simultaneous determination of eleven estrogenic and odorous chloro- and bromo-phenolic compounds was developed. The target chemicals included seven chlorophenols (CPs): 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2-chloro-4-methyl phenol (2-C-4-MP), 4-chloro-2-methyl phenol (4-C-2-MP), 4-chloro-3-methyl phenol (4-C-3-MP), 2,6-dichlorophenol (2,6-DCP), and 2,4,5-trichlorophenol (2,4,5-TCP) and four bromophenols (BPs): 2-bromophenol (2-BP), 2,6-dichlorophenol (2,6-DBP), 2,4-dichlorophenol (2,4-DBP), and 2,4,6-tribromophenol (2,4,6-TBP). The extraction temperature, extraction time, derivatization time, salt concentration and pH of sample solution were optimized and determined in this study. The developed method using the optimized conditions was validated with respect to the linearity (R2 > 0.991), low limit of detection (LOD, 8.8–42.9 ng L−1), and excellent recoveries (69–108%) with a low relative standard deviation (RSD, 1.5–18.6%). This method provides an effective online extraction and derivatization process with good sensitivity in GC-MS, and can be applied for the efficient determination of chloro- and bromo-phenolic compounds in surface water.

28 citations

References
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Book
01 Jan 1996
TL;DR: The cause of disruptions in animal breeding cycles, accompanied by increases in birth defects, sexual abnormalities and reproductive failure, is traced to the pervasive presence in the environment of chemicals that mimic hormones and trick the reproductive system.
Abstract: For years, scientists have noticed disruptions in animal breeding cycles, accompanied by increases in birth defects, sexual abnormalities and reproductive failure. Humans are not immune either, with sperm counts dropping by as much as 50% in recent decades and with women seeing a rise in hormone-related cancers, endometriosis and other disorders. This book traces the cause of these aberrations and diseases to the pervasive presence in the environment of chemicals that mimic hormones and trick the reproductive system. The conclusions are as obvious as they are inescapable - unless we make vital changes in the way we manufacture and employ the artefacts of our "good life", there will be no life at all.

917 citations