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Goodson WH, Lowe L, Gilbertson M, Carpenter DO. Testing the low dose mixtures hypothesis from the Halifax project. REVIEWS ON ENVIRONMENTAL HEALTH 2020; 35:333-357. [PMID: 32833669 DOI: 10.1515/reveh-2020-0033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/02/2020] [Indexed: 05/24/2023]
Abstract
In 2013, 60 scientists, representing a larger group of 174 scientists from 26 nations, met in Halifax, Nova Scotia to consider whether - using published research - it was logical to anticipate that a mixture of chemicals, each thought to be non-carcinogenic, might act together in that mixture as a virtual carcinogen. The group identified 89 such chemicals, each one affecting one or more Hallmark(s) - collectively covering all Hallmarks of Cancer - confirming the possibility that a chemical mixture could induce all the Hallmarks and function as a virtual carcinogen, thereby supporting the concern that chemical safety research that does not evaluate mixtures, is incomplete. Based on these observations, the Halifax Project developed the Low-Dose Carcinogenesis Hypothesis which posits "…that low-dose exposures to [mixtures of] disruptive chemicals that are not individually carcinogenic may be capable of instigating and/or enabling carcinogenesis." Although testing all possible combinations of over 80,000 chemicals of commerce would be impractical, prudence requires designing a methodology to test whether low-dose chemical mixtures might be carcinogenic. As an initial step toward testing this hypothesis, we conducted a mini review of published empirical observations of biological exposures to chemical mixtures to assess what empirical data exists on which to base future research. We reviewed studies on chemical mixtures with the criteria that the studies reported both different concentrations of chemicals and mixtures composed of different chemicals. We found a paucity of research on this important question. The majority of studies reported hormone related processes and used chemical concentrations selected to facilitate studying how mixtures behave in experiments that were often removed from clinical relevance, i.e., chemicals were not studied at human-relevant concentrations. New research programs must be envisioned to enable study of how mixtures of small doses of chemicals affect human health, starting, when at all possible, from non-malignant specimens when studies are done in vitro. This research should use human relevant concentrations of chemicals, expand research beyond the historic focus on endocrine endpoints and endocrine related cancers, and specifically seek effects that arise uniquely from exposure to chemical mixtures at human-relevant concentrations.
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Affiliation(s)
- William H Goodson
- Department of Surgery, California Pacific Medical Center Research Institute, San Francisco, CA, 94115, USA
| | - Leroy Lowe
- Getting to Know Cancer (NGO), Truro, NS, B2N 1X5, Canada
| | - Michael Gilbertson
- Occupational and Environmental Health Research Group, University of Stirling, Stirling, Scotland
| | - David O Carpenter
- Institute for Health and the Environment, University at Albany, Rensselaer, NY, 12144, USA
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Fallahi S, Mlnaříková M, Alvord C, Alendal G, Frøysa HG, Lundh T, Celander MC. New Conceptual Toxicokinetic Model to Assess Synergistic Mixture Effects between the Aromatic Hydrocarbon β-Naphthoflavone and the Azole Nocodazole on the CYP1A Biomarker in a Fish Cell Line. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:13748-13758. [PMID: 33054185 PMCID: PMC7884012 DOI: 10.1021/acs.est.0c04839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/19/2020] [Accepted: 10/01/2020] [Indexed: 06/11/2023]
Abstract
Toxicokinetic interactions with catabolic cytochrome P450 (CYP) enzymes can inhibit chemical elimination pathways and cause synergistic mixture effects. We have created a mathematical bottom-up model for a synergistic mixture effect where we fit a multidimensional function to a given data set using an auxiliary nonadditive approach. The toxicokinetic model is based on the data from a previous study on a fish cell line, where the CYP1A enzyme activity was measured over time after exposure to various combinations of the aromatic hydrocarbon β-naphthoflavone and the azole nocodazole. To describe the toxicokinetic mechanism in this pathway and how that affects the CYP1A biomarker, the model uses ordinary differential equations. Local sensitivity and identifiability analyses revealed that all the 10 parameters estimated in the model were identified uniquely while fitting the model to the data for measuring the CYP1A enzyme activity. The model has a good prediction power and is a promising tool to test the synergistic toxicokinetic interactions between different chemicals.
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Affiliation(s)
- Shirin Fallahi
- Department
of Mathematics, University of Bergen, P.O. Box 7803, Bergen N 5020, Norway
| | - Marie Mlnaříková
- Department
of Biological and Environmental Sciences, University of Gothenburg, P.O. 463, Gothenburg SE 405 30, Sweden
| | - Charlotte Alvord
- Department
of Biological and Environmental Sciences, University of Gothenburg, P.O. 463, Gothenburg SE 405 30, Sweden
| | - Guttorm Alendal
- Department
of Mathematics, University of Bergen, P.O. Box 7803, Bergen N 5020, Norway
| | - Håvard G. Frøysa
- Department
of Mathematics, University of Bergen, P.O. Box 7803, Bergen N 5020, Norway
| | - Torbjörn Lundh
- Mathematical
Sciences, Chalmers University of Technology
and the University of Gothenburg, Gothenburg SE 412 96, Sweden
| | - Malin C. Celander
- Department
of Biological and Environmental Sciences, University of Gothenburg, P.O. 463, Gothenburg SE 405 30, Sweden
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Dairkee SH, Luciani-Torres G, Moore DH, Jaffee IM, Goodson WH. A Ternary Mixture of Common Chemicals Perturbs Benign Human Breast Epithelial Cells More Than the Same Chemicals Do Individually. Toxicol Sci 2019; 165:131-144. [PMID: 29846718 PMCID: PMC6135635 DOI: 10.1093/toxsci/kfy126] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
As a continuous source of hormonal stimulation, environmentally ubiquitous estrogenic chemicals, ie, xenoestrogens (XEs), are a potential risk factor for breast carcinogenesis. Given their wide distribution in the environment and the fact that bisphenol-A (BPA), methylparaben (MP), and perfluorooctanoic acid (PFOA) are uniformly detected in unselected body fluid samples, it must be assumed that humans are simultaneously exposed to these chemicals almost daily. We studied the effects of a ternary mixture of BPA, MP, and PFOA on benign breast epithelial cells at the range of concentrations observed for single chemicals in human samples. Measurements of exposure impact relevant to the breast were based on endpoints associated with “hallmarks” of cancer and “key characteristics” of carcinogens. These included modulation of total estrogen receptor (ER)α, phosphorylated ERα (pERα), total ERβ, S-phase induction, and apoptotic evasion. Data from live cell measurements were fit to a log-linear dose-response model. Concentration-dependent reduction of ERβ and apoptosis evasion was observed concurrently with the induction of ERα, pERα, and S-phase fraction, and an increased rate of cell proliferation. Beyond additive effects predicted by the sum of individual test XEs, mixture treatment demonstrated synergism for the ERβ and apoptosis suppression phenotypes (p > .001). Nonmalignant breast cells were more sensitive than commonly used breast cancer lines to XE treatment in 3 of 5 endpoints. All observations were validated with cells isolated from the normal breast tissue of 14 individuals. At relatively low concentrations, a chemical mixture has striking effects on normal cell function that are missed by evaluation of single components.
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Affiliation(s)
| | | | - Dan H Moore
- California Pacific Medical Center Research Institute
| | - Ian M Jaffee
- Department of Pathology, California Pacific Medical Center, San Francisco, California 94107
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Johansson HKL, Svingen T, Fowler PA, Vinggaard AM, Boberg J. Environmental influences on ovarian dysgenesis - developmental windows sensitive to chemical exposures. Nat Rev Endocrinol 2017; 13:400-414. [PMID: 28450750 DOI: 10.1038/nrendo.2017.36] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A woman's reproductive health and ability to have children directly affect numerous aspects of her life, from personal well-being and socioeconomic standing, to morbidity and lifespan. In turn, reproductive health depends on the development of correctly functioning ovaries, a process that starts early during fetal life. Early disruption to ovarian programming can have long-lasting consequences, potentially manifesting as disease much later in adulthood. A growing body of evidence suggests that exposure to chemicals early in life, including endocrine-disrupting chemicals, can cause a range of disorders later in life, such as those described in the ovarian dysgenesis syndrome hypothesis. In this Review, we discuss four specific time windows during which the ovary is particularly sensitive to disruption by exogenous insults: gonadal sex determination, meiotic division, follicle assembly and the first wave of follicle recruitment. To date, most evidence points towards the germ cell lineage being the most vulnerable to chemical exposure, particularly meiotic division and follicle assembly. Environmental chemicals and pharmaceuticals, such as bisphenols or mild analgesics (including paracetamol), can also affect the somatic cell lineages. This Review summarizes our current knowledge pertaining to environmental chemicals and pharmaceuticals, and their potential contributions to the development of ovarian dysgenesis syndrome. We also highlight knowledge gaps that need addressing to safeguard female reproductive health.
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Affiliation(s)
- Hanna Katarina Lilith Johansson
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kemitorvet, Building 202, DK-2800 Kgs. Lyngby, Denmark
| | - Terje Svingen
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kemitorvet, Building 202, DK-2800 Kgs. Lyngby, Denmark
| | - Paul A Fowler
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Anne Marie Vinggaard
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kemitorvet, Building 202, DK-2800 Kgs. Lyngby, Denmark
| | - Julie Boberg
- Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kemitorvet, Building 202, DK-2800 Kgs. Lyngby, Denmark
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Tubbs CW, Moley LA, Ivy JA, Metrione LC, LaClaire S, Felton RG, Durrant BS, Milnes MR. Estrogenicity of captive southern white rhinoceros diets and their association with fertility. Gen Comp Endocrinol 2016; 238:32-38. [PMID: 27167501 DOI: 10.1016/j.ygcen.2016.05.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 04/26/2016] [Accepted: 05/06/2016] [Indexed: 11/30/2022]
Abstract
The captive southern white rhinoceros (SWR) population is not currently self-sustaining, primarily due to poor or absent reproduction of captive-born (F1+) females. In this study, we investigate the role of dietary phytoestrogens in this reproductive phenomenon by characterizing activation of SWR estrogen receptors (ESRs) 1 and 2 by diet items from nine North American institutions and comparing female SWR fertility to total diet estrogenicity. Of the diet items tested, alfalfa hay and soy and alfalfa-based commercial pellets were found to be the most potent activators of SWR ESRs. In contrast, most grass hays tested were not estrogenic. The estrogenicity of total diets varied across the institutions surveyed and the degree of diet estrogenicity was positively associated with the percentage of the total diet comprised by pellets. Comparisons of fertility records of the institutions surveyed showed no significant relationship between diet estrogenicity and fertility for female SWR conceived or born in the wild (F0). However, for F1+ females, there was a significant negative relationship between institutional diet estrogenicity and fertility. Taken together, these data suggest that developmental exposure to phytoestrogens may be the cause of poor fertility in captive-born female SWR. Whether the low fertility of the current population of captive-born female SWR is permanent or can be reversed by removing phytoestrogens from the diet remains unclear. However, our findings suggest that in order for the SWR population to become self-sustaining, the development and feeding of low phytoestrogen diets should be strongly considered.
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Affiliation(s)
- Christopher W Tubbs
- San Diego Zoo Global, Institute for Conservation Research, 15600 San Pasqual Valley Road, Escondido, CA 92027, United States.
| | - Laura A Moley
- San Diego Zoo Global, Institute for Conservation Research, 15600 San Pasqual Valley Road, Escondido, CA 92027, United States
| | - Jamie A Ivy
- San Diego Zoo Global, Life Sciences, P.O. Box 120551, San Diego, CA 92112, United States
| | - Lara C Metrione
- South-East Zoo Alliance for Reproduction and Conservation, 581705 White Oak Road, Yulee, FL 32097, United States
| | - Sydney LaClaire
- San Diego Zoo Global, Institute for Conservation Research, 15600 San Pasqual Valley Road, Escondido, CA 92027, United States
| | - Rachel G Felton
- San Diego Zoo Global, Institute for Conservation Research, 15600 San Pasqual Valley Road, Escondido, CA 92027, United States
| | - Barbara S Durrant
- San Diego Zoo Global, Institute for Conservation Research, 15600 San Pasqual Valley Road, Escondido, CA 92027, United States
| | - Matthew R Milnes
- Mars Hill University, P.O. Box 6671, 100 Athletic Street, Mars Hill, NC 28754, United States
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Interaction Effects between Organochlorine Pesticides and Isoflavones In Vitro and In Vivo. BIOMED RESEARCH INTERNATIONAL 2016; 2016:6861702. [PMID: 27597971 PMCID: PMC5002470 DOI: 10.1155/2016/6861702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/25/2016] [Accepted: 06/16/2016] [Indexed: 12/25/2022]
Abstract
Organochlorine pesticides (OCPs) have caused increasing global concern due to their high toxicity, persistence, bioaccumulation, and significant adverse effects on human health. This study was to explore the interaction effects between OCPs and isoflavones. Six kinds of OCPs and 2 kinds of isoflavones-genistein and daidzein were included to study their effect on MCF-7 cells in vitro. Eighty-one female Sprague-Dawley rats were randomized to 9 groups according to factorial design to study the interaction effect between isoflavones and γ-HCH. Compared to organochlorine pesticides alone group, proliferation rate of MCF-7 cells was lower in 100 μmol/L genistein + organochlorine pesticides and 100 μmol/L daidzein + organochlorine pesticides group (p < 0.05). In vivo study showed that there are interaction effects on kidney weight and liver weight when treated with isoflavones and γ-HCH. The changes in uterine morphology and positive expression of ERα showed inhibition effects between isoflavones and γ-HCH. In conclusion, the data suggests that there are interactions between isoflavones and OCPs in vitro and in vivo.
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Shappell NW, Flythe MD, Aiken GE. The Effects of Steroid Implant and Dietary Soybean Hulls on Estrogenic Activity of Sera of Steers Grazing Toxic Endophyte-Infected Tall Fescue Pasture. Front Vet Sci 2015; 2:30. [PMID: 26664959 PMCID: PMC4672223 DOI: 10.3389/fvets.2015.00030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 08/21/2015] [Indexed: 11/13/2022] Open
Abstract
Soybean hulls (SBHs) have been fed to cattle pasturing on endophyte-infected tall fescue in attempts to increase rate of gain. Literature reports indicated some symptoms associated with fescue toxicosis were ameliorated by the use of steroidal implants containing estradiol (E2) and progesterone [implantation (IMP)], feeding SBHs, or the combination of the two. While the mechanism for amelioration was unclear, the SBHs were postulated as acting as a diluent of the toxic factors of the fescue. Alternatively, estradiol and phytoestrogens of SBHs might be acting through relaxation of the persistent vasoconstriction found in animals ingesting ergot alkaloids of endophyte-infected fescue. If so, estrogenic activity of serum of steers receiving SBHs, IMP, or a combination of the two should be elevated. Using the cellular proliferation assay of estrogenicity (E-Screen), estradiol equivalents (E2Eqs) were determined on both SBHs and the serum of steers from a previously reported study. Range of SBHs was 5.0–8.5 ng Eqs g−1 DM (mean 6.5, n = 4 from different commercial sources of SBHs). At the rate fed, theoretically calculated blood E2Eq could be physiologically relevant (~80 pg mL−1, based on 2.3 kg SBHs d−1, 300 kg steer, 5.7% blood volume, and 10% absorption). Serum E2Eqs did increase in steers (P ≤ 0.05) with steroidal implants or fed SBHs by 56 and 151% over control, respectively, and treatments were additive (211% increase). Serum prolactin was also greatest for the SBH + IMP group (188 ng mL−1, P < 0.05), concentrations comparable to values reported for steers grazing endophyte-free fescue. Prolactin in the SBH group was higher than IMP or control groups (146 versus 76 and 60 ng mL−1, respectively). Still unknown is if additional E2Eqs from dietary phytoestrogens or exogenous sources of estradiol can further reduce symptoms of fescue toxicosis. The E-Screen assay was an effective tool in monitoring serum for estrogenic effects of dietary supplementation with SBHs or estrogenic implants.
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Affiliation(s)
- Nancy W Shappell
- USDA-ARS Animal Metabolism-Agricultural Chemicals Research , Fargo, ND , USA
| | - Michael D Flythe
- USDA-ARS Forage-Animal Production Research Unit , Lexington, KY , USA
| | - Glen E Aiken
- USDA-ARS Forage-Animal Production Research Unit , Lexington, KY , USA
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8
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Kumar D, Thakur MK. Perinatal exposure to bisphenol-A impairs spatial memory through upregulation of neurexin1 and neuroligin3 expression in male mouse brain. PLoS One 2014; 9:e110482. [PMID: 25330104 PMCID: PMC4201550 DOI: 10.1371/journal.pone.0110482] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 09/21/2014] [Indexed: 11/19/2022] Open
Abstract
Bisphenol-A (BPA), a well known endocrine disruptor, impairs learning and memory in rodents. However, the underlying molecular mechanism of BPA induced impairment in learning and memory is not well known. As synaptic plasticity is the cellular basis of memory, the present study investigated the effect of perinatal exposure to BPA on the expression of synaptic proteins neurexin1 (Nrxn1) and neuroligin3 (Nlgn3), dendritic spine density and spatial memory in postnatal male mice. The pregnant mice were orally administered BPA (50 µg/kgbw/d) from gestation day (GD) 7 to postnatal day (PND) 21 and sesame oil was used as a vehicle control. In Morris water maze (MWM) test, BPA extended the escape latency time to locate the hidden platform in 8 weeks male mice. RT-PCR and Immunoblotting results showed significant upregulation of Nrxn1 and Nlgn3 expression in both cerebral cortex and hippocampus of 3 and 8 weeks male mice. This was further substantiated by in-situ hybridization and immunofluorescence techniques. BPA also significantly increased the density of dendritic spines in both regions, as analyzed by rapid Golgi staining. Thus our data suggest that perinatal exposure to BPA impairs spatial memory through upregulation of expression of synaptic proteins Nrxn1 and Nlgn3 and increased dendritic spine density in cerebral cortex and hippocampus of postnatal male mice.
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Affiliation(s)
- Dhiraj Kumar
- Biochemistry and Molecular Biology Laboratory, Brain Research Centre, Department of Zoology, Banaras Hindu University, Varanasi, India
| | - Mahendra Kumar Thakur
- Biochemistry and Molecular Biology Laboratory, Brain Research Centre, Department of Zoology, Banaras Hindu University, Varanasi, India
- * E-mail:
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Ramirez T, Buechse A, Dammann M, Melching-Kollmuß S, Woitkowiak C, van Ravenzwaay B. Effect of estrogenic binary mixtures in the yeast estrogen screen (YES). Regul Toxicol Pharmacol 2014; 70:286-96. [DOI: 10.1016/j.yrtph.2014.07.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 05/31/2014] [Accepted: 07/06/2014] [Indexed: 11/26/2022]
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Lee DH, Porta M, Jacobs DR, Vandenberg LN. Chlorinated persistent organic pollutants, obesity, and type 2 diabetes. Endocr Rev 2014; 35:557-601. [PMID: 24483949 PMCID: PMC5393257 DOI: 10.1210/er.2013-1084] [Citation(s) in RCA: 296] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Persistent organic pollutants (POPs) are lipophilic compounds that travel with lipids and accumulate mainly in adipose tissue. Recent human evidence links low-dose POPs to an increased risk of type 2 diabetes (T2D). Because humans are contaminated by POP mixtures and POPs possibly have nonmonotonic dose-response relations with T2D, critical methodological issues arise in evaluating human findings. This review summarizes epidemiological results on chlorinated POPs and T2D, and relevant experimental evidence. It also discusses how features of POPs can affect inferences in humans. The evidence as a whole suggests that, rather than a few individual POPs, background exposure to POP mixtures-including organochlorine pesticides and polychlorinated biphenyls-can increase T2D risk in humans. Inconsistent statistical significance for individual POPs may arise due to distributional differences in POP mixtures among populations. Differences in the observed shape of the dose-response curves among human studies may reflect an inverted U-shaped association secondary to mitochondrial dysfunction or endocrine disruption. Finally, we examine the relationship between POPs and obesity. There is evidence in animal studies that low-dose POP mixtures are obesogenic. However, relationships between POPs and obesity in humans have been inconsistent. Adipose tissue plays a dual role of promoting T2D and providing a relatively safe place to store POPs. Large prospective studies with serial measurements of a broad range of POPs, adiposity, and clinically relevant biomarkers are needed to disentangle the interrelationships among POPs, obesity, and the development of T2D. Also needed are laboratory experiments that more closely mimic real-world POP doses, mixtures, and exposure duration in humans.
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Affiliation(s)
- Duk-Hee Lee
- Department of Preventive Medicine (D.-H.L.), School of Medicine, Kyungpook National University, Daegu 700-422, Korea; BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science (D.-H.L.), Kyungpook National University, Korea; Hospital del Mar Institute of Medical Research (M.P.), School of Medicine, Universitat Autonoma de Barcelona, and Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública, Barcelona 08193, Spain; Division of Epidemiology (D.R.J.), School of Public Health, University of Minnesota, Minneapolis, Minnesota 55455; Department of Nutrition (D.R.J.), University of Oslo, 0313 Oslo, Norway; and University of Massachusetts-Amherst (L.N.V.), School of Public Health, Division of Environmental Health Sciences, Amherst, Massachusetts 01003
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Huang X, Huang J, Zhang L, Zhu Y, Li Y. A novel ERα-mediated reporter gene assay for screening estrogenic/antiestrogenic chemicals based on LLC-MK2 cells. Toxicol Mech Methods 2014; 24:627-32. [PMID: 25045971 DOI: 10.3109/15376516.2014.945107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Low concentration of endocrine-disrupting chemicals (EDCs) may lead to serious consequences in animals and human, so it is essential to develop an effective assay for EDCs detection. In this study, we developed a novel ERα-mediated reporter gene assay based on the LLC-MK2 cells by co-transfecting pERE-sv40-Luc, hERα-pcDNA3.1, and pRL-tk. Then we determined 17β-estradiol (E2) and some estrogenic/antiestrogenic chemicals to verify the validity of this assay. Data showed that the assay possesses a concentration-dependent responses to E2 and diethylstilbestrol (DES) from 10(-12 )M to 10(-8 )M with EC(50) 3.4 × 10(-10 )M and 5.9 × 10(-10 )M, and ICI 182,780 completely blocks the luciferase activity induced by 10(-9 )M E2. Bisphenol A (BPA), nonylphenol (NP), genistein (GS), and tamoxifen (TAM) also showed corresponding estrogenic or antiestrogenic activity at test concentrations. All evidences proved that the LLC-MK2 reporter gene assay was specific and sensitive to estrogen receptor (ER) agonistic and antagonistic chemicals.
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Affiliation(s)
- Xiaoming Huang
- Department of Nutrition and Food Hygiene, West China School of Public Health, Sichuan University , Chengdu, Sichuan , PR China and
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Becker RA, Hays SM, Kirman CR, Aylward LL, Wise K. Interpreting Estrogen Screening Assays in the Context of Potency and Human Exposure Relative to Natural Exposures to Phytoestrogens. ACTA ACUST UNITED AC 2014; 101:114-24. [DOI: 10.1002/bdrb.21085] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 11/08/2013] [Indexed: 01/11/2023]
Affiliation(s)
| | | | | | | | - Kimberly Wise
- American Chemistry Council Washington District of Columbia
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13
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Schilirò T, Porfido A, Longo A, Coluccia S, Gilli G. The E-screen test and the MELN gene-reporter assay used for determination of estrogenic activity in fruits and vegetables in relation to pesticide residues. Food Chem Toxicol 2013; 62:82-90. [DOI: 10.1016/j.fct.2013.07.067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 07/22/2013] [Accepted: 07/24/2013] [Indexed: 12/14/2022]
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Nohynek GJ, Borgert CJ, Dietrich D, Rozman KK. Endocrine disruption: fact or urban legend? Toxicol Lett 2013; 223:295-305. [PMID: 24177261 DOI: 10.1016/j.toxlet.2013.10.022] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Revised: 10/02/2013] [Accepted: 10/21/2013] [Indexed: 10/26/2022]
Abstract
Endocrine disruptors (EDs) are substances that cause adverse health effects via endocrine-mediated mechanisms in an intact organism or its progeny or (sub) populations. Purported EDCs in personal care products include 4-MBC (UV filter) or parabens that showed oestrogenic activity in screening tests, although regulatory toxicity studies showed no adverse effects on reproductive endpoints. Hormonal potency is the key issue of the safety of EDCs. Oestrogen-based drugs, e.g. the contraceptive pill or the synthetic oestrogen DES, possess potencies up to 7 orders of magnitude higher than those of PCP ingredients; yet, in utero exposure to these drugs did not adversely affect fertility or sexual organ development of offspring unless exposed to extreme doses. Additive effects of EDs are unlikely due to the multitude of mechanisms how substances may produce a hormone-like activity; even after uptake of different substances with a similar mode of action, the possibility of additive effects is reduced by different absorption, metabolism and kinetics. This is supported by a number of studies on mixtures of chemical EDCs. Overall, despite of 20 years of research a human health risk from exposure to low concentrations of exogenous chemical substances with weak hormone-like activities remains an unproven and unlikely hypothesis.
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deCatanzaro D, Berger RG, Guzzo AC, Thorpe JB, Khan A. Perturbation of male sexual behavior in mice (Mus musculus) within a discrete range of perinatal bisphenol-A doses in the context of a high- or low-phytoestrogen diet. Food Chem Toxicol 2013; 55:164-71. [DOI: 10.1016/j.fct.2012.12.046] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 12/24/2012] [Accepted: 12/27/2012] [Indexed: 12/19/2022]
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16
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Jašarević E, Williams SA, Vandas GM, Ellersieck MR, Liao C, Kannan K, Roberts RM, Geary DC, Rosenfeld CS. Sex and dose-dependent effects of developmental exposure to bisphenol A on anxiety and spatial learning in deer mice (Peromyscus maniculatus bairdii) offspring. Horm Behav 2013; 63:180-9. [PMID: 23051835 PMCID: PMC3540128 DOI: 10.1016/j.yhbeh.2012.09.009] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 09/27/2012] [Accepted: 09/28/2012] [Indexed: 02/02/2023]
Abstract
Bisphenol A (BPA) is a widely produced, endocrine disrupting compound that is pervasive in the environment. Data suggest that developmental exposure to BPA during sexual differentiation of the brain leads to later behavioral consequences in offspring. Outbred deer mice (Peromyscus maniculatus bairdii) are an excellent animal model for such studies as they exhibit well-defined sex- and steroid-dependent behaviors. Here, dams during gestation and lactation were fed with a phytoestrogen-free control diet, the same diet supplemented with either ethinyl estradiol (0.1 ppb), or one of the three doses of BPA (50 mg, 5 mg, 50 μg/kg feed weight). After weaning, the pups were maintained on control diet until they reached sexual maturity and then assessed for both spatial learning capabilities and anxiety-like and exploratory behaviors. Relative to controls, males exposed to the two upper but not the lowest dose of BPA demonstrated similar impairments in spatial learning, increased anxiety and reduced exploratory behaviors as ethinyl estradiol-exposed males, while females exposed to ethinyl estradiol, but not to BPA, consistently exhibited masculinized spatial abilities. We also determined whether dams maintained chronically on the upper dose of BPA contained environmentally relevant concentrations of BPA in their blood. While serum concentrations of unconjugated BPA in controls were below the minimum level of detection, those from dams on the BPA diet were comparable (5.48±2.07 ng/ml) to concentrations that have been observed in humans. Together, these studies demonstrate that developmental exposure to environmentally relevant concentrations of BPA can disrupt adult behaviors in a dose- and sex-dependent manner.
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Affiliation(s)
- Eldin Jašarević
- Interdisciplinary Neuroscience Program, Center for Translational Neuroscience, University of Missouri, Columbia MO 65211
- Department of Psychological Sciences, University of Missouri, Columbia MO 65211
- Thompson Center for Autism and Neurodevelopmental Disorders, University of Missouri, Columbia MO 65211
| | - Scott A. Williams
- Division of Biological Sciences, University of Missouri, Columbia MO 65211
- Bond Life Sciences Center, University of Missouri, Columbia MO 65211
| | - Gregory M. Vandas
- Division of Biological Sciences, University of Missouri, Columbia MO 65211
- Bond Life Sciences Center, University of Missouri, Columbia MO 65211
| | - Mark R. Ellersieck
- College of Agriculture Food and Nutritional Resources-Statitician, University of Missouri, Columbia MO 65211
| | - Chunyang Liao
- Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Albany, NY
| | - Kurunthachalam Kannan
- Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Albany, NY
| | - R. Michael Roberts
- Bond Life Sciences Center, University of Missouri, Columbia MO 65211
- Department of Animal Sciences, University of Missouri, Columbia MO 65211
- Department of Biochemistry, University of Missouri, Columbia MO 65211
| | - David C. Geary
- Interdisciplinary Neuroscience Program, Center for Translational Neuroscience, University of Missouri, Columbia MO 65211
- Department of Psychological Sciences, University of Missouri, Columbia MO 65211
| | - Cheryl S. Rosenfeld
- Bond Life Sciences Center, University of Missouri, Columbia MO 65211
- Department of Biomedical Sciences, University of Missouri, Columbia MO 65211
- Corresponding author: Biomedical Sciences and Bond Life Sciences Center, University of Missouri, 440F Bond Life Sciences Center, 1201 E. Rollins Rd., Columbia, MO 65211. , phone: (573) 882-5132, and fax: (573) 884-9395.
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Crawford BR, Decatanzaro D. Disruption of blastocyst implantation by triclosan in mice: impacts of repeated and acute doses and combination with bisphenol-A. Reprod Toxicol 2012; 34:607-13. [PMID: 23059059 DOI: 10.1016/j.reprotox.2012.09.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 08/20/2012] [Accepted: 09/11/2012] [Indexed: 01/31/2023]
Abstract
Triclosan is an antimicrobial additive in many personal care and household products, and evidence indicates that it can be estrogenic. As estrogen elevations can disrupt blastocyst implantation, we examined the influence of triclosan on implantation in inseminated mice. Doses of 18 and 27 mg/animal/day (about 523 and 785 mg/kg/day) on gestational days (GD) 1-3 reduced the number of implantation sites on GD 6. Single doses on GD 2 or 3 also reduced implantation sites. Subsequently, we examined triclosan in combination with bisphenol-A (BPA), which also can disrupt implantation. Although doses of 4 mg BPA (122 mg/kg) and 9 mg triclosan (262 mg/kg) on GD 1-3 were individually ineffective, in combination they reduced the number of implantation sites and also increased gestation length. All of these effects mimicked stronger effects of 17β-estradiol. These data are consistent with potential estrogenic properties of triclosan, and show that it can act together with BPA.
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Affiliation(s)
- Brent R Crawford
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada
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Schilirò T, Gorrasi I, Longo A, Coluccia S, Gilli G. Endocrine disrupting activity in fruits and vegetables evaluated with the E-screen assay in relation to pesticide residues. J Steroid Biochem Mol Biol 2011; 127:139-46. [PMID: 21397020 DOI: 10.1016/j.jsbmb.2011.03.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 01/25/2011] [Accepted: 03/02/2011] [Indexed: 11/19/2022]
Abstract
Food is likely to be one of the most important routes of human exposure to endocrine disrupting compounds (EDCs). In the present study, we evaluated the total estrogenic activity of fruits and vegetables, which was calculated using the human breast cancer cell line (MCF-7 BUS) proliferation assay (E-screen), in relation to pesticide residues. We analysed 44 food samples, 30 fruits and 14 vegetables. Of these samples, 10 did not contain any pesticide residues. The other 34 samples contained from 1 to 7 pesticide residues in concentrations ranging from 0.03 to 1.91 ppm. Estrogenic activity was detected in the 59% of samples tested. The positive controls used were 17-β-estradiol (E2), the phytoestrogen genistein and the pesticide endosulfan. The average value of estradiol equivalency quantity (EEQ) for all positive samples was 0.15±0.32 μg/100g. A low correlation was found between the concentration of pesticide residues and the EEQ values (Spearman correlation r=0.376 and p=0.012). Using values obtained from the literature, we compared the estrogenic activity of food samples with the intrinsic content of phytoestrogens, but we found no correlations. Our results also suggested that the calculated intake of dietary EDCs might represent a concentration comparable to the normal endogenous estrogen concentration in human blood.
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Affiliation(s)
- T Schilirò
- Department of Public Health and Microbiology, University of Torino, Torino, Italy.
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Kelce WR, Borgert CJ. In vitro detection of estrogen activity in plastic products using a sensitive bioassay: failure to acknowledge limitations. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:a378-a379. [PMID: 21885376 PMCID: PMC3230411 DOI: 10.1289/ehp.1103894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Silva E, Rajapakse N, Scholze M, Backhaus T, Ermler S, Kortenkamp A. Joint Effects of Heterogeneous Estrogenic Chemicals in the E-Screen—Exploring the Applicability of Concentration Addition. Toxicol Sci 2011; 122:383-94. [DOI: 10.1093/toxsci/kfr103] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Marty MS, Carney EW, Rowlands JC. Endocrine Disruption: Historical Perspectives and Its Impact on the Future of Toxicology Testing. Toxicol Sci 2010; 120 Suppl 1:S93-108. [DOI: 10.1093/toxsci/kfq329] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Fernández M, Bourguignon N, Lux-Lantos V, Libertun C. Neonatal exposure to bisphenol a and reproductive and endocrine alterations resembling the polycystic ovarian syndrome in adult rats. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:1217-22. [PMID: 20413367 PMCID: PMC2944080 DOI: 10.1289/ehp.0901257] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Accepted: 04/22/2010] [Indexed: 05/20/2023]
Abstract
BACKGROUND Bisphenol A (BPA), an endocrine disruptor, is a component of polycarbonate plastics, epoxy resins, and polystyrene. Several studies have reported potent in vivo effects, because BPA behaves as an estrogen agonist and/or antagonist and as an androgen and thyroid hormone antagonist. OBJECTIVES We investigated the effects of neonatal exposure to BPA on the reproductive axis in adult female Sprague-Dawley rats. METHODS Female rats were injected subcutaneously, daily from postnatal day 1 (PND1) to PND10 with BPA in castor oil at 500 microg/50 microL [BPA500; approximately 10-4 M, a dose higher than the lowest observed adverse effect level (LOAEL) of 50 mg/kg], 50 microg/50 microL (BPA50), or 5 microg/50 microL (both BPA50 and BPA5 are doses lower than the LOAEL), or castor oil vehicle alone. In adults we studied a) the release of gonadotropin-releasing hormone (GnRH) from hypothalamic explants, b) serum sex hormone levels, and c) ovarian morphology, ovulation, and fertility. RESULTS Neonatal exposure to BPA was associated with increased serum testosterone and estradiol levels, reduced progesterone in adulthood, and altered in vitro GnRH secretion. Animals exposed to BPA500 had altered ovarian morphology, showing a large number of cysts. Animals exposed to BPA50 had reduced fertility without changes in the number of oocytes on the morning of estrus, whereas animals exposed to BPA500 showed infertility. CONCLUSIONS Exposure to high doses of BPA during the period of brain sexual differentiation altered the hypothalamic-pituitary-gonadal axis in female Sprague-Dawley rats. These results have the potential to link neonatal exposure to high doses of BPA in rats with the development of polycystic ovarian syndrome. Studies of doses and routes of administration more consistent with human exposures are needed to determine the relevance of these findings to human health.
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Affiliation(s)
- Marina Fernández
- Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina
- Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Nadia Bourguignon
- Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina
| | | | - Carlos Libertun
- Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina
- Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
- Address correspondence to C. Libertun, IByME-CONICET, Vuelta de Obligado 2490, (C1428ADN) Buenos Aires, Argentina. Telephone: 54-11-4783-2869. Fax: 54-11-4786-2564. E-mail:
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Sahambi SK, Pelland A, Cooke GM, Schrader T, Tardif R, Charbonneau M, Krishnan K, Haddad S, Cyr DG, Devine PJ. Oral p-tert-octylphenol exposures induce minimal toxic or estrogenic effects in adult female Sprague-Dawley rats. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2010; 73:607-622. [PMID: 20391140 DOI: 10.1080/15287390903566682] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Contamination of the environment with endocrine-disrupting chemicals (EDC) has raised concerns about potential health hazards for humans and wildlife. Human and wildlife exposure to one such ubiquitous chemical, p-tert-octylphenol (OP), are likely, due to its persistence in the environment and its presence in food, water, and items of daily use. OP is reported to bind to the estrogen receptor (ER) and alter expression of estrogen-responsive genes. Detrimental effects of OP exposures on the reproductive system have been observed in most, but not all, in vivo experiments. This study examined estrogenic effects of oral exposures of adult female rats to OP. In vitro, OP bound weakly to human ER and a co-activator protein, and accelerated proliferation of MCF-7 cells. Adult Sprague-Dawley rats were given OP by gavage daily for 35 d (25, 50, or 125 mg/kg/d). Body and organ weights and ovarian follicle populations were not significantly altered in OP-exposed adult rats, despite detectable levels of OP in reproductive organs. The estrous cycle of rats was slightly altered, but there were no significant estrogen-like changes in histomorphology or gene expression of the uterus. Prepubertal rats given 125 or 250 mg/kg OP by gavage for 3 d had reduced body weight compared to vehicle-exposed rats but failed to show any uterotrophic response, although 17alpha-ethinyl estradiol (EE, 10 microg/kg/d, ip) induced a threefold increase in uterine weight. Overall, results suggest that toxicity will occur before estrogenic effects with oral exposures to OP. Relevant environmental exposures likely pose little risk for estrogenic effects.
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Affiliation(s)
- Sukhdeep K Sahambi
- INRS-Institut Armand-Frappier, Institut national de la recherche scientifique, Laval, Québec, Canada
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Bolca S, Wyns C, Possemiers S, Depypere H, De Keukeleire D, Bracke M, Verstraete W, Heyerick A. Cosupplementation of isoflavones, prenylflavonoids, and lignans alters human exposure to phytoestrogen-derived 17beta-estradiol equivalents. J Nutr 2009; 139:2293-300. [PMID: 19864398 DOI: 10.3945/jn.109.113639] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The microbial metabolism of dietary phytoestrogens varies considerably among individuals and influences the final exposure to bioactive compounds. In view of the increasing number of food supplements combining several classes of phytoestrogens, the microbial potential to activate various proestrogens within an individual was evaluated in 3 randomized dietary crossovers. Treatment allocation was based on participants' eligibility (>45% in vitro bioactivation of >or=2 separate proestrogens by fecal cultures; n = 40/100). After a run-in of >or=4 d, participants were given soy-, hop-, and/or flax-based food supplements dosed either separately (SOY: 2.83 mg daidzein aglycone equivalents/supplement, HOP: 1.20 mg isoxanthohumol (IX)/supplement, or FLAX: 2.08 mg secoisolariciresinol (SECO) aglycone equivalents/supplement; reference intervention) or simultaneously (MIX; test intervention) 3 times/d for 5 d, followed by a wash-out period (>or=7 d) and the second intervention. Before and after each (co)supplementation, spot urine and serum were collected. In total, 22 equol, 19 8-prenylnaringenin (8-PN), and 21 enterolactone (ENL) producers completed the SOY+MIX, HOP+MIX, and FLAX+MIX trials, respectively. The microbial bioactivation of daidzein, IX, and SECO, generally decreased upon coincubation in vitro (equol: 4.4%, P = 0.164; 8-PN: 20.5%, P < 0.001; ENL: 44.3%, P < 0.001) and cosupplementation in vivo (equol: 28.3%, P = 0.009; 8-PN: 35.4%, P = 0.107; ENL: 35.9%, P = 0.003). Although the bioavailabilities of total isoflavones, prenylflavonoids, and lignans were not significantly affected upon coadministration, participants were exposed to lower phytoestrogen-derived 17beta-estradiol equivalents. In conclusion, the bioavailability of phytoestrogens, especially when given in mixtures, is subject to high interindividual variation. These findings support the importance of personalized screening when assessing the efficacy of such products and mixtures.
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Affiliation(s)
- Selin Bolca
- Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Rochester JR, Millam JR. Phytoestrogens and avian reproduction: Exploring the evolution and function of phytoestrogens and possible role of plant compounds in the breeding ecology of wild birds. Comp Biochem Physiol A Mol Integr Physiol 2009; 154:279-88. [PMID: 19559809 DOI: 10.1016/j.cbpa.2009.06.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 06/19/2009] [Accepted: 06/19/2009] [Indexed: 11/26/2022]
Abstract
Phytoestrogens are secondary plant compounds, which can act to mimic estrogen and cause the disruption of estrogenic responses in organisms. Although there is a substantial body of research studying phytoestrogens, including their mechanisms of estrogenic effects, evolution, and detection in biological systems, little is known about their ecological significance. There is evidence, however, that an ecological relationship involving phytoestrogens exists between plants and animals-plants may produce phytoestrogens to reduce fecundity of organisms that eat them. Birds and other vertebrates may also exploit phytoestrogens to regulate their own reproduction-there are well known examples of phytoestrogens inhibiting reproduction in higher vertebrates, including birds. Also, common plant stressors (e.g., high temperature) increase the production of secondary plant compounds, and, as evidence suggests, also induce phytoestrogen biosynthesis. These observations are consistent with the single study ever done on phytoestrogens and reproduction in wild birds [Leopold, A.S., Erwin, M., Oh, J., Browning, B., 1976. Phytoestrogens adverse effects on reproduction in California quail. Science 191, 98-100.], which found that drought stress correlated with increased levels of phytoestrogens in plants, and that increased phytoestrogen levels correlated with decreased young. This review discusses the hypothesis that plants may have an effect on the reproduction of avian species by producing phytoestrogens as a plant defense against herbivory, and that birds may "use" changing levels of phytoestrogens in the vegetation to ensure that food resources will support potential young produced. Evidence from our laboratory and others appear to support this hypothesis.
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What you see may not always be what you get – Bioavailability and extrapolation from in vitro tests. Toxicol In Vitro 2008; 22:1038-42. [DOI: 10.1016/j.tiv.2007.12.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2007] [Revised: 12/20/2007] [Accepted: 12/21/2007] [Indexed: 10/22/2022]
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Current World Literature. Curr Opin Obstet Gynecol 2007; 19:289-96. [PMID: 17495648 DOI: 10.1097/gco.0b013e3281fc29db] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
PURPOSE OF REVIEW Modern consumer needs have stimulated a vast expansion in the dietary supplement market, in an attempt to improve general well being and prevent, rather than cure, disease. Isoflavones form a large part of this market. Their oestrogenic properties are still largely unknown and must be thoroughly researched to ensure they cause no adverse effects, particularly on hormone-dependent reproductive physiology. RECENT FINDINGS As a result of the increasing availability of phytoestrogens, research into their actions now covers a very wide field, many of which impact on reproductive potential. Time of exposure is crucial, as is interaction with other dietary components. Their putative role as chemoprotective agents has been expanded in recent years which may have an indirect impact on fertility by decreasing mortality rates in both men and women. SUMMARY Phytoestrogens are still a current research topic in reproduction and fertility. Genistein is a putative therapeutic tool in cancer treatment although this must be considered along with evidence that it may cause DNA damage in sperm, depending on the concentration. The effects of phytoestrogen in the body are not limited to oestrogenic action. Much more epidemiological data are required to interpret current molecular studies, and those of previous years.
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