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Grgic D, Novak B, Varga E, Marko D. Estrogen receptor α interaction of zearalenone and its phase I metabolite α-zearalenol in combination with soy isoflavones in hERα-HeLa-9903 cells. Mycotoxin Res 2024; 40:97-109. [PMID: 37847468 PMCID: PMC10834624 DOI: 10.1007/s12550-023-00506-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 09/10/2023] [Accepted: 10/05/2023] [Indexed: 10/18/2023]
Abstract
Risk assessment primarily relies on toxicological data of individual substances, with limited information on combined effects. Recent in vitro experiments using Ishikawa cells, an endometrial carcinoma cell line expressing both estrogen receptor isoforms, demonstrated interactive effects of phyto- and mycoestrogens. The mycoestrogens, zearalenone (ZEN), and α-zearalenol (α-ZEL) exhibited significantly enhanced estrogenic responses in the presence of isoflavones (ISF), depending on substance ratios and concentrations. This study investigated the impact of phyto- and mycoestrogen combinations on estrogenic response following OECD guideline 455, utilizing hERα-HeLa-9903 cells. Test substances included mycoestrogens (ZEN and α-ZEL) and isoflavones (genistein (GEN), daidzein (DAI), and S-equol (EQ), a gut microbial metabolite of DAI). Mycoestrogens were tested in the range of 0.001 to 100 nM, while isoflavones were used at concentrations 1000 times higher based on relevant occurrence ratios. Results showed that ZEN and α-ZEL induced ERα-dependent luciferase expression in concentrations above 1 nM and 0.01 nM, respectively. However, ISF caused a superinduction of the luciferase signal above 1 µM. A superinduction is characterized by an unusually strong or heightened increase in the activity of the luciferase enzyme. This signal is not affected by the estrogen receptor antagonist 4-hydroxytamoxifen (4-OH-TAM), which was additionally used to verify whether the increase of signal is a true reflection of receptor activation. This superinduction was observed in all combinations of ZEN and α-ZEL with ISFs. Contrary to the luciferase activity findings, RT-qPCR experiments and a stability approach revealed lower real ERα activation by ISFs than measured in the ONE-Glo™ luciferase test system. In conclusion, the OECD protocol 455 appears unsuitable for testing ISFs due to their superinduction of luciferase and interactions with the test system, resulting in experimental artifacts. Further studies are necessary to explore structure-activity relationships within polyphenols and clarify the test system's applicability.
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Affiliation(s)
- Dino Grgic
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, Währinger Str. 38-40, 1090, Vienna, Austria
- University of Vienna, Doctoral School in Chemistry, Währinger Str. 38-42, 1090, Vienna, Austria
| | - Barbara Novak
- dsm-firmenich, ANH R&D center, Technopark 1, 3430, Tulln, Austria
| | - Elisabeth Varga
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, Währinger Str. 38-40, 1090, Vienna, Austria.
- Present address: Unit Food Hygiene and Technology, Institute of Food Safety, Food Technology and Veterinary Public Health, University of Veterinary Medicine, Vienna, Veterinärplatz 1, 1210, Vienna, Austria.
| | - Doris Marko
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, Währinger Str. 38-40, 1090, Vienna, Austria
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Eze CT, Otitoloju AA, Eze OO, Ugochukwu TE, Onodugo C, Ali AM, Lyche JL, Karlsen OA, Goksøyr A. West African e-waste-soil assessed with a battery of cell-based bioassays. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159068. [PMID: 36179844 DOI: 10.1016/j.scitotenv.2022.159068] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 09/17/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
Soil samples randomly taken from major e-waste sites in West Africa (Nigeria, Benin and Ghana) were examined for an extensive range of organic contaminants. Cytotoxicity measurements and assessment of activation of xeno-sensing receptors from fish (Atlantic cod) were employed as a battery of in vitro biological assays to explore the quality and toxicity profile of West African e-waste soil. The concentrations of the measured contaminants of emerging concerns (CECs) and persistent organic pollutants (POPs) in the e-waste soil differs significantly from the reference soil with chemical profiles typically dominated by legacy polybrominated diphenyl ethers (PBDEs) (405.8 μgkg-1) and emerging organophosphate ester flame retardant tris (1-chloro-2-propyl) phosphate (TCPP) (404 μgkg-1), in addition to the short chain perfluorobutane sulfonate (PFBS) (275.3 μgkg-1) and perfluorobutanoate (PFBA) (16 μgkg-1). The study revealed that perfluorooctanoic acid (PFOA) occurred only in e-waste soil from Ghana and ranged from 2.6 to 5.0 μgkg-1. Overall, non-polar e-waste soil-derived extracts had a stronger effect on COS-7 cell viability than the polar extracts and elutriates. The highest receptor activation was observed with single polar and non-polar extracts from the Nigeria and Benin sites, indicating hotspots with Er-, PPARa- and Ahr-agonist activities. Thus, the results obtained with our battery of in vitro biological assays underscored these e-waste sites as remarkably polluted spots with complex toxicity profiles of great concern for human and environmental health.
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Affiliation(s)
- Chukwuebuka ThankGod Eze
- Department of Biochemistry, Federal University Oye-Ekiti, Ekiti State, Nigeria; Department of Zoology, University of Lagos, Akoka-Yaba, Lagos State, Nigeria; Department of Biological Sciences, University of Bergen, Bergen, Norway.
| | | | | | | | - Chinemelum Onodugo
- Department of Biochemistry, Federal University Oye-Ekiti, Ekiti State, Nigeria
| | - Aasim Musa Ali
- Section of Contaminants and Biohazards, Institute of Marine Research (IMR), P.O 1870 Nordnes, NO-5817 Bergen, Norway
| | - Jan Ludvig Lyche
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, Norway
| | - Odd André Karlsen
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Anders Goksøyr
- Department of Biological Sciences, University of Bergen, Bergen, Norway
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3
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Fang J, Wang D, Kramer NI, Rietjens IMCM, Boogaard PJ, Kamelia L. The role of receptor-mediated activities of 4- and 5-ring unsubstituted and methylated polycyclic aromatic hydrocarbons (PAHs) in developmental toxicity. J Appl Toxicol 2022; 43:845-861. [PMID: 36585251 DOI: 10.1002/jat.4428] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 12/11/2022] [Accepted: 12/22/2022] [Indexed: 01/01/2023]
Abstract
The present study evaluated the aryl hydrocarbon receptor (AhR), estrogen receptor-α (ER-α), and retinoic acid receptor (RAR) mediated activities of nine 4- and 5-ring unsubstituted and monomethylated polycyclic aromatic hydrocarbons (PAHs) using a series of Chemical-Activated LUciferase gene eXpression (CALUX) assays. The potential role of these aforementioned receptors in relation to the developmental toxicity of these PAHs was further assessed in the zebrafish embryotoxicity test (ZET). The results show that all nine tested PAHs were AhR agonists, benz[a]anthracene (BaA) and 8-methyl-benz[a]anthracene (8-MeBaA) were ER-α agonists, and none of the tested PAHs induced ER-α antagonistic or RAR (ant)agonistic activities. In the AhR CALUX assay, all the methylated PAHs showed higher potency (lower EC50) in activating the AhR than their respective unsubstituted PAHs, implying that the addition of a methyl substituent on the aromatic ring of PAHs could enhance their AhR-mediated activities. Co-exposure of zebrafish embryos with each individual PAH and an AhR antagonist (CH223191) counteracted the observed developmental retardations and embryo lethality to a certain extent, except for 8-methyl-benzo[a]pyrene (8-MeBaP). Co-exposure of zebrafish embryos with either of the two estrogenic PAHs (i.e., BaA and 8-MeBaA) and an ER-α antagonist (fulvestrant) neutralized embryo lethality induced by 50 μM BaA and the developmental retardations induced by 15 μM 8-MeBaA. Altogether, our findings suggest that the observed developmental retardations in zebrafish embryos by the PAH tested may partially be AhR- and/or ER-α-mediated, whereas the RAR seems not to be relevant for the PAH-induced developmental toxicity in the ZET.
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Affiliation(s)
- Jing Fang
- Division of Toxicology, Wageningen University and Research, Wageningen, 6708 WE, The Netherlands
| | - Danlei Wang
- Division of Toxicology, Wageningen University and Research, Wageningen, 6708 WE, The Netherlands
| | - Nynke I Kramer
- Division of Toxicology, Wageningen University and Research, Wageningen, 6708 WE, The Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University and Research, Wageningen, 6708 WE, The Netherlands
| | - Peter J Boogaard
- Division of Toxicology, Wageningen University and Research, Wageningen, 6708 WE, The Netherlands
| | - Lenny Kamelia
- Shell Global Solutions International B.V., The Hague, The Netherlands
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Kornhuber M, Dunst S, Schönfelder G, Oelgeschläger M. The E-Morph Assay: Identification and characterization of environmental chemicals with estrogenic activity based on quantitative changes in cell-cell contact organization of breast cancer cells. ENVIRONMENT INTERNATIONAL 2021; 149:106411. [PMID: 33549916 DOI: 10.1016/j.envint.2021.106411] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/11/2021] [Accepted: 01/18/2021] [Indexed: 06/12/2023]
Abstract
Adverse health effects that are caused by endocrine disrupting chemicals (EDCs) in the environment, food or consumer products are of high public concern. The identification and characterization of EDCs including substances with estrogenic activity still necessitates the use of animal testing as most of the approved alternative test methods only address single mechanistic events of endocrine activity. Therefore, novel human-relevant in vitro assays covering more complex functional endpoints of adversity, including hormone-related tumor formation and progression, are needed. This study describes the development and evaluation of a novel high-throughput screening-compatible assay called "E-Morph Assay". This image-based phenotypic screening assay facilitates robust predictions of the estrogenic potential of environmental chemicals using quantitative changes in the cell-cell contact morphology of human breast cancer cells as a novel functional endpoint. Based on a classification model, which was developed using six reference substances with known estrogenic activity, the E-Morph Assay correctly classified an additional set of 11 reference chemicals commonly used in OECD Test Guidelines and the U.S. EPA ToxCast program. For each of the tested substances, a relative ER bioactivity score was derived that allowed their grouping into four main categories of estrogenic activity, i.e. 'strong' (>0.9; four substances, i.e. natural hormones or pharmaceutical products), 'moderate' (0.9-0.6; six substances, i.e. phytoestrogens and Bisphenol AF), 'weak' (<0.6; three substances, i.e Bisphenol S, B, and A), and 'negative' (0.0; four substances). The E-Morph Assay considerably expands the portfolio of test methods providing the possibility to characterize the influence of environmental chemicals on estrogen-dependent tumor progression.
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Affiliation(s)
- Marja Kornhuber
- German Federal Institute for Risk Assessment (BfR), German Centre for the Protection of Laboratory Animals (Bf3R), 10589 Berlin, Germany; Freie Universität Berlin, 14195 Berlin, Germany
| | - Sebastian Dunst
- German Federal Institute for Risk Assessment (BfR), German Centre for the Protection of Laboratory Animals (Bf3R), 10589 Berlin, Germany
| | - Gilbert Schönfelder
- German Federal Institute for Risk Assessment (BfR), German Centre for the Protection of Laboratory Animals (Bf3R), 10589 Berlin, Germany; Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany
| | - Michael Oelgeschläger
- German Federal Institute for Risk Assessment (BfR), German Centre for the Protection of Laboratory Animals (Bf3R), 10589 Berlin, Germany.
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Dahlin JL, Auld DS, Rothenaigner I, Haney S, Sexton JZ, Nissink JWM, Walsh J, Lee JA, Strelow JM, Willard FS, Ferrins L, Baell JB, Walters MA, Hua BK, Hadian K, Wagner BK. Nuisance compounds in cellular assays. Cell Chem Biol 2021; 28:356-370. [PMID: 33592188 PMCID: PMC7979533 DOI: 10.1016/j.chembiol.2021.01.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 01/02/2021] [Accepted: 01/27/2021] [Indexed: 12/17/2022]
Abstract
Compounds that exhibit assay interference or undesirable mechanisms of bioactivity ("nuisance compounds") are routinely encountered in cellular assays, including phenotypic and high-content screening assays. Much is known regarding compound-dependent assay interferences in cell-free assays. However, despite the essential role of cellular assays in chemical biology and drug discovery, there is considerably less known about nuisance compounds in more complex cell-based assays. In our view, a major obstacle to realizing the full potential of chemical biology will not just be difficult-to-drug targets or even the sheer number of targets, but rather nuisance compounds, due to their ability to waste significant resources and erode scientific trust. In this review, we summarize our collective academic, government, and industry experiences regarding cellular nuisance compounds. We describe assay design strategies to mitigate the impact of nuisance compounds and suggest best practices to efficiently address these compounds in complex biological settings.
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Affiliation(s)
- Jayme L Dahlin
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA.
| | - Douglas S Auld
- Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA
| | - Ina Rothenaigner
- Assay Development and Screening Platform, Helmholtz Zentrum Muenchen, 85764 Neuherberg, Germany
| | - Steve Haney
- Indiana Biosciences Research Institute, Indianapolis, IN 46202, USA
| | - Jonathan Z Sexton
- Department of Internal Medicine, Gastroenterology, Michigan Medicine at the University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Jarrod Walsh
- Hit Discovery, Discovery Sciences, R&D, AstraZeneca, Alderley Park SK10 4TG, UK
| | | | | | | | - Lori Ferrins
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA
| | - Jonathan B Baell
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia; School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing 211816, People's Republic of China
| | - Michael A Walters
- Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, MN 55414, USA
| | - Bruce K Hua
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA 02140, USA; Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02140, USA
| | - Kamyar Hadian
- Assay Development and Screening Platform, Helmholtz Zentrum Muenchen, 85764 Neuherberg, Germany
| | - Bridget K Wagner
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA 02140, USA
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6
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Rooney J, Ryan N, Liu J, Houtman R, van Beuningen R, Hsieh JH, Chang G, Chen S, Christopher Corton J. A Gene Expression Biomarker Identifies Chemical Modulators of Estrogen Receptor α in an MCF-7 Microarray Compendium. Chem Res Toxicol 2021; 34:313-329. [PMID: 33405908 PMCID: PMC10683854 DOI: 10.1021/acs.chemrestox.0c00243] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Identification of chemicals that affect hormone-regulated systems will help to predict endocrine disruption. In our previous study, a 46 gene biomarker was found to be an accurate predictor of estrogen receptor (ER) α modulation in chemically treated MCF-7 cells. Here, potential ERα modulators were identified using the biomarker by screening a microarray compendium consisting of ∼1600 gene expression comparisons representing exposure to ∼1200 chemicals. A total of ∼170 chemicals were identified as potential ERα modulators. In the Connectivity Map 2.0 collection, 75 and 39 chemicals were predicted to activate or suppress ERα, and they included 12 and six known ERα agonists and antagonists/selective ERα modulators, respectively. Nineteen and eight of the total number were also identified as active in an ERα transactivation assay carried out in an MCF-7-derived cell line used to screen the Tox21 10K chemical library in agonist or antagonist modes, respectively. Chemicals predicted to modulate ERα in MCF-7 cells were examined further using global and targeted gene expression in wild-type and ERα-null cells, transactivation assays, and cell-free ERα coregulator interaction assays. Environmental chemicals classified as weak and very weak agonists were confirmed to activate ERα including apigenin, kaempferol, and oxybenzone. Novel activators included digoxin, nabumetone, ivermectin, and six progestins. Novel suppressors included emetine, mifepristone, niclosamide, and proscillaridin. Our strategy will be useful to identify environmentally relevant ERα modulators in future high-throughput transcriptomic screens.
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Affiliation(s)
- John Rooney
- Center for Computational Toxicology and Exposure, US-EPA, Research Triangle Park, NC 27711
- Present address: Integrated Lab Services, Research Triangle Park, NC
| | - Natalia Ryan
- Center for Computational Toxicology and Exposure, US-EPA, Research Triangle Park, NC 27711
- Present address: Bayer Crop Science, Research Triangle Park, NC
| | - Jie Liu
- Center for Computational Toxicology and Exposure, US-EPA, Research Triangle Park, NC 27711
| | - René Houtman
- PamGene International B.V., Den Bosch, The Netherlands
- Present address: Precision Medicine Lab, Oss, The Netherlands
| | | | - Jui-Hua Hsieh
- Kelly Government Solutions, Research Triangle Park, North Carolina
| | - Gregory Chang
- Department of Cancer Biology, Beckman Research Institute of the City of Hope, Duarte,California 91010
| | - Shiuan Chen
- Department of Cancer Biology, Beckman Research Institute of the City of Hope, Duarte,California 91010
| | - J. Christopher Corton
- Center for Computational Toxicology and Exposure, US-EPA, Research Triangle Park, NC 27711
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Comparative genotoxic potential of 27 polycyclic aromatic hydrocarbons in three human cell lines. Toxicol Lett 2020; 326:99-105. [DOI: 10.1016/j.toxlet.2020.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 02/27/2020] [Accepted: 03/09/2020] [Indexed: 12/31/2022]
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Wang Q, Spenkelink B, Boonpawa R, Rietjens IMCM, Beekmann K. Use of Physiologically Based Kinetic Modeling to Predict Rat Gut Microbial Metabolism of the Isoflavone Daidzein to S-Equol and Its Consequences for ERα Activation. Mol Nutr Food Res 2020; 64:e1900912. [PMID: 32027771 PMCID: PMC7154660 DOI: 10.1002/mnfr.201900912] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 11/06/2019] [Indexed: 12/13/2022]
Abstract
SCOPE To predict gut microbial metabolism of xenobiotics and the resulting plasma concentrations of metabolites formed, an in vitro-in silico-based testing strategy is developed using the isoflavone daidzein and its gut microbial metabolite S-equol as model compounds. METHODS AND RESULTS Anaerobic rat fecal incubations are optimized and performed to derive the apparent maximum velocities (Vmax ) and Michaelis-Menten constants (Km ) for gut microbial conversion of daidzein to dihydrodaidzein, S-equol, and O-desmethylangolensin, which are input as parameters for a physiologically based kinetic (PBK) model. The inclusion of gut microbiota in the PBK model allows prediction of S-equol concentrations and slightly reduced predicted maximal daidzein concentrations from 2.19 to 2.16 µm. The resulting predicted concentrations of daidzein and S-equol are comparable to in vivo concentrations reported. CONCLUSION The optimized in vitro approach to quantify kinetics for gut microbial conversions, and the newly developed PBK model for rats that includes gut microbial metabolism, provide a unique tool to predict the in vivo consequences of daidzein microbial metabolism for systemic exposure of the host to daidzein and its metabolite S-equol. The predictions reveal a dominant role for daidzein in ERα-mediated estrogenicity despite the higher estrogenic potency of its microbial metabolite S-equol.
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Affiliation(s)
- Qianrui Wang
- Division of ToxicologyWageningen University and ResearchWageningen6708 WEThe Netherlands
| | - Bert Spenkelink
- Division of ToxicologyWageningen University and ResearchWageningen6708 WEThe Netherlands
| | - Rungnapa Boonpawa
- Faculty of Natural Resources and Agro‐IndustryKasetsart University Chalermphrakiat Sakon Nakhon Province CampusSakon Nakhon47000Thailand
| | | | - Karsten Beekmann
- Division of ToxicologyWageningen University and ResearchWageningen6708 WEThe Netherlands
- Present address:
Wageningen Food Safety ResearchP. O. Box 2306700 AEWageningenThe Netherlands
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Gramec Skledar D, Tvrdý V, Kenda M, Zega A, Pour M, Horký P, Mladěnka P, Sollner Dolenc M, Peterlin Mašič L. Applicability of the OECD 455 in-vitro assay for determination of hERa agonistic activity of isoflavonoids. Toxicol Appl Pharmacol 2019; 386:114831. [PMID: 31756431 DOI: 10.1016/j.taap.2019.114831] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/30/2019] [Accepted: 11/16/2019] [Indexed: 12/12/2022]
Abstract
The Organisation for Economic Co-operation and Development (OECD)-validated transactivation assay using the human estrogen receptor alpha (hERα) Hela9903 cell line is used for activity evaluation of hERα agonists and antagonists. Due to many advantages, this assay is broadly used as an initial screening process. However, response significantly higher from that of 17-β estradiol (E2) was observed with phytoestrogens for concentrations commonly above 1 μM in previous studies. The main aim of this study was thus to ascertain the applicability of OECD protocol 455 for evaluation of estrogenic activity of natural flavonoids, including known phytoestrogens. The estrogenic activities of aglycones as well as of O-methylated and glycosylated flavonoids were evaluated. Supra-maximal luciferase activity was seen for most of the flavonoids tested at concentrations even below 1 μM. hERα-mediated luciferase expression was confirmed with the competition assay specified in OECD protocol 455. However, at concentrations above 1 μM, non-specific interactions were also observed. Instead of EC50 values, which could not be determined for most of the isoflavonoids tested, the concentrations corresponding to 10% (PC10) and 50% (PC50) of the maximum activity of the positive control, E2, were used for quantitative determination of estrogenic activities. Appropriate evaluation of the data obtained with the current OECD protocol 455 validated assay represents a valuable tool for initial screening of natural flavonoids for estrogenic activity.
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Affiliation(s)
- Darja Gramec Skledar
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Václav Tvrdý
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Charles University, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Maša Kenda
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Anamarija Zega
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Milan Pour
- Department of Organic and Bioorganic Chemistry, Faculty of Pharmacy, Charles University, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Pavel Horký
- Department of Organic and Bioorganic Chemistry, Faculty of Pharmacy, Charles University, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Přemysl Mladěnka
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Charles University, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | | | - Lucija Peterlin Mašič
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia.
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Papadi G, Wesseling S, Troganis AN, Vervoort J, Rietjens IMCM. Induction of EpRE-mediated gene expression by a series of mediterranean botanicals and their constituents. JOURNAL OF ETHNOPHARMACOLOGY 2019; 240:111940. [PMID: 31071423 DOI: 10.1016/j.jep.2019.111940] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 05/04/2019] [Accepted: 05/05/2019] [Indexed: 06/09/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE A variety of Mediterranean plant species, traditionally used for the prevention and treatment of several health conditions, contain ingredients with potential biological activity of which many remain unexplored. Among the beneficial health effects of bioactive phytochemicals is the activation of cellular defense mechanisms involving the activation of EpRE (electrophile responsive element) - mediated changes in gene expression. AIM OF THE STUDY The present study aimed to identify botanicals and their active constituents able to activate the EpRE mediated gene expression within a series of Mediterranean plant species known for their hepatoprotective and/or cardioprotective properties. MATERIALS AND METHODS Methanolic extracts of 18 botanicals were prepared and tested for their ability to induce gene expression in EpRE-LUX reporter cells. Subsequently, LC-MS (Liquid Chromatography Mass Spectrometry) analysis combined with MAGMa (MS Annotation based on in silico Generated Metabolites) software for automated compound annotation was used to facilitate tentative identification of the active constituents within two of the active extracts. Selected annotated compounds were tested in the EpRE-LUX reporter gene assay followed by definite identification of the most active ones. RESULTS It appeared that 9 of the 18 extracts were able to activate EpRE-mediated gene expression. Many active ingredients of the methanolic extracts from Juglans regia and Rhamnus frangula were revealed. Among them, chrysophanol and aloe-emodin were confirmed to be active EpRE inducing ingredients and were definitely identified in the Rhamnus Frangula extract. CONCLUSIONS The protective effect of half of the tested botanical varieties via the activation of EpRE-mediated gene expression was confirmed. The study also provided an example of how in vitro bioassays can be combined with LC-MS and the automated chemical annotation software MAGMa, to identify biologically active constituents in complex botanical extracts.
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Affiliation(s)
- Georgia Papadi
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708, WE, Wageningen, The Netherlands; Department of Biological Applications & Technology, University of Ioannina, 45110, Ioannina, Greece.
| | - Sebastiaan Wesseling
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708, WE, Wageningen, The Netherlands.
| | - Anastassios N Troganis
- Department of Biological Applications & Technology, University of Ioannina, 45110, Ioannina, Greece.
| | - Jacques Vervoort
- Laboratory of Biochemistry, Wageningen University and Research, Stippeneng 4, 6708, WE, Wageningen, The Netherlands.
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708, WE, Wageningen, The Netherlands.
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11
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García-Herranz V, Valdehita A, Navas J, Fernández-Cruz M. Cytotoxicity against fish and mammalian cell lines and endocrine activity of the mycotoxins beauvericin, deoxynivalenol and ochratoxin-A. Food Chem Toxicol 2019; 127:288-297. [DOI: 10.1016/j.fct.2019.01.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/10/2019] [Accepted: 01/29/2019] [Indexed: 12/15/2022]
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12
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Stable cellular models of nuclear receptor PXR for high-throughput evaluation of small molecules. Toxicol In Vitro 2018; 52:222-234. [PMID: 29933105 DOI: 10.1016/j.tiv.2018.06.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 05/28/2018] [Accepted: 06/18/2018] [Indexed: 12/11/2022]
Abstract
Pregnane & Xenobiotic Receptor (PXR) is one of the 48 members of the ligand-modulated transcription factors belonging to nuclear receptor superfamily. Though PXR is now well-established as a 'xenosensor', regulating the central detoxification and drug metabolizing machinery, it has also emerged as a key player in several metabolic disorders. This makes PXR attractive to both, researchers and pharmaceutical industry since clinical success of small drug molecules can be pre-evaluated on PXR platform. At the early stages of drug discovery, cell-based assays are used for high-throughput screening of small molecules. The future success or failure of a drug can be predicted by this approach saving expensive resources and time. In view of this, we have developed human liver cell line-based, dual-level screening and validation protocol on PXR platform having application to assess small molecules. We have generated two different stably transfected cell lines, (i) a stable promoter-reporter cell line (HepXREM) expressing PXR and a commonly used CYP3A4 promoter-reporter i.e. XREM-luciferase; and (ii) two stable cell lines integrated with proximal PXR-promoter-reporter (Hepx-1096/+43 and Hepx-497/+43). Employing HepXREM, Hepx-1096/+43 and Hepx-497/+43 stable cell lines > 25 anti-cancer herbal drug ingredients were screened for examining their modulatory effects on a) PXR transcriptional activity and, b) PXR-promoter activity. In conclusion, the present report provides a convenient and economical, dual-level screening system to facilitate the identification of superior therapeutic small molecules.
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Pěnčíková K, Svržková L, Strapáčová S, Neča J, Bartoňková I, Dvořák Z, Hýžďalová M, Pivnička J, Pálková L, Lehmler HJ, Li X, Vondráček J, Machala M. In vitro profiling of toxic effects of prominent environmental lower-chlorinated PCB congeners linked with endocrine disruption and tumor promotion. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 237:473-486. [PMID: 29518658 PMCID: PMC5908724 DOI: 10.1016/j.envpol.2018.02.067] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/20/2018] [Accepted: 02/20/2018] [Indexed: 05/18/2023]
Abstract
The mechanisms contributing to toxic effects of airborne lower-chlorinated PCB congeners (LC-PCBs) remain poorly characterized. We evaluated in vitro toxicities of environmental LC-PCBs found in both indoor and outdoor air (PCB 4, 8, 11, 18, 28 and 31), and selected hydroxylated metabolites of PCB 8, 11 and 18, using reporter gene assays, as well as other functional cellular bioassays. We focused on processes linked with endocrine disruption, tumor promotion and/or regulation of transcription factors controlling metabolism of both endogenous compounds and xenobiotics. The tested LC-PCBs were found to be mostly efficient anti-androgenic (within nanomolar - micromolar range) and estrogenic (at micromolar concentrations) compounds, as well as inhibitors of gap junctional intercellular communication (GJIC) at micromolar concentrations. PCB 8, 28 and 31 were found to partially inhibit the aryl hydrocarbon receptor (AhR)-mediated activity. The tested LC-PCBs were also partial constitutive androstane receptor (CAR) and pregnane X receptor (PXR) agonists, with PCB 4, 8 and 18 being the most active compounds. They were inactive towards other nuclear receptors, such as vitamin D receptor, thyroid receptor α, glucocorticoid receptor or peroxisome proliferator-activated receptor γ. We found that only PCB 8 contributed to generation of oxidative stress, while all tested LC-PCBs induced arachidonic acid release (albeit without further modulations of arachidonic acid metabolism) in human lung epithelial cells. Importantly, estrogenic effects of hydroxylated (OH-PCB) metabolites of LC-PCBs (4-OH-PCB 8, 4-OH-PCB 11 and 4'-OH-PCB 18) were higher than those of the parent PCBs, while their other toxic effects were only slightly altered or suppressed. This suggested that metabolism may alter toxicity profiles of LC-PCBs in a receptor-specific manner. In summary, anti-androgenic and estrogenic activities, acute inhibition of GJIC and suppression of the AhR-mediated activity were found to be the most relevant modes of action of airborne LC-PCBs, although they partially affected also additional cellular targets.
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Affiliation(s)
- Kateřina Pěnčíková
- Department of Chemistry and Toxicology, Veterinary Research Institute, Hudcova 70, 62100 Brno, Czech Republic
| | - Lucie Svržková
- Department of Chemistry and Toxicology, Veterinary Research Institute, Hudcova 70, 62100 Brno, Czech Republic
| | - Simona Strapáčová
- Department of Chemistry and Toxicology, Veterinary Research Institute, Hudcova 70, 62100 Brno, Czech Republic
| | - Jiří Neča
- Department of Chemistry and Toxicology, Veterinary Research Institute, Hudcova 70, 62100 Brno, Czech Republic
| | - Iveta Bartoňková
- Department of Cell Biology and Genetics, Faculty of Science, Šlechtitelů 11, Palacký University, 78371 Olomouc, Czech Republic
| | - Zdeněk Dvořák
- Department of Cell Biology and Genetics, Faculty of Science, Šlechtitelů 11, Palacký University, 78371 Olomouc, Czech Republic
| | - Martina Hýžďalová
- Department of Chemistry and Toxicology, Veterinary Research Institute, Hudcova 70, 62100 Brno, Czech Republic; Department of Cytokinetics, Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 61265 Brno, Czech Republic
| | - Jakub Pivnička
- Department of Cytokinetics, Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 61265 Brno, Czech Republic
| | - Lenka Pálková
- Department of Chemistry and Toxicology, Veterinary Research Institute, Hudcova 70, 62100 Brno, Czech Republic
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, 52242, IA, USA
| | - Xueshu Li
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, 52242, IA, USA
| | - Jan Vondráček
- Department of Cytokinetics, Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 61265 Brno, Czech Republic.
| | - Miroslav Machala
- Department of Chemistry and Toxicology, Veterinary Research Institute, Hudcova 70, 62100 Brno, Czech Republic.
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14
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Auld DS, Narahari J, Ho PI, Casalena D, Nguyen V, Cirbaite E, Hughes D, Daly J, Webb B. Characterization and Use of TurboLuc Luciferase as a Reporter for High-Throughput Assays. Biochemistry 2018; 57:4700-4706. [PMID: 29641191 DOI: 10.1021/acs.biochem.8b00290] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Luciferase-based reporter assays are powerful tools for monitoring gene expression in cells because of their ultrasensitive detection capacity and wide dynamic range. Here we describe the characterization and use of a luciferase reporter enzyme derived from the marine copepod Metridia luciferase family, referred to as TurboLuc luciferase (TurboLuc). To develop TurboLuc, the wild-type luciferase was modified to decrease its size, increase brightness, slow luminescent signal decay, and provide for efficient intracellular expression. To determine the enzyme susceptibility to compound inhibition and judge the suitability of using of TurboLuc as a reporter in screening assays, purified TurboLuc enzyme was screened for inhibitors using two different compound libraries. No inhibitors of this enzyme were identified in a library representative of typical diverse low molecular weight (LMW) compounds using a purified TurboLuc enzyme assay supporting that such libraries will show very low interference with this enzyme. We were able to identify a few inhibitors from a purified natural product library which can serve as useful tools to validate assays using TurboLuc. In addition to the inhibitor profile for TurboLuc we describe the use of this reporter in cells employing miniaturized assay volumes within 1536-well plates. TurboLuc luciferase is the smallest luciferase reporter enzyme described to date (16 kDa), shows bright luminescence and low interference by LMW compounds, and therefore should provide an ideal reporter in assays applied to high-throughput screening.
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Affiliation(s)
- Douglas S Auld
- Chemical Biology and Therapeutics , Novartis Institutes for Biomedical Research , 250 Massachusetts Avenue , Cambridge , Massachusetts , United States
| | - Janaki Narahari
- Thermo Fisher Scientific , Rockford , Illinois , United States
| | - Pei-I Ho
- Chemical Biology and Therapeutics , Novartis Institutes for Biomedical Research , 250 Massachusetts Avenue , Cambridge , Massachusetts , United States
| | - Dominick Casalena
- Chemical Biology and Therapeutics , Novartis Institutes for Biomedical Research , 250 Massachusetts Avenue , Cambridge , Massachusetts , United States
| | - Vy Nguyen
- Chemical Biology and Therapeutics , Novartis Institutes for Biomedical Research , 250 Massachusetts Avenue , Cambridge , Massachusetts , United States
| | | | - Doug Hughes
- Thermo Fisher Scientific , Rockford , Illinois , United States
| | - John Daly
- Gene Stream Pty Ltd , Perth , Australia
| | - Brian Webb
- Thermo Fisher Scientific , Rockford , Illinois , United States
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15
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Prinsloo G, Marokane CK, Street RA. Anti-HIV activity of southern African plants: Current developments, phytochemistry and future research. JOURNAL OF ETHNOPHARMACOLOGY 2018; 210:133-155. [PMID: 28807850 PMCID: PMC7125770 DOI: 10.1016/j.jep.2017.08.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 08/02/2017] [Accepted: 08/03/2017] [Indexed: 05/15/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The African continent is home to a large number of higher plant species used over centuries for many applications, which include treating and managing diseases such as HIV. Due to the overwhelming prevalence and incidence rates of HIV, especially in sub-Saharan Africa, it is necessary to develop new and affordable treatments. AIM OF THE STUDY The article provides an extensive overview of the status on investigation of plants from the southern African region with ethnobotanical use for treating HIV or HIV-related symptoms, or the management of HIV. The review also provide an account of the in vitro assays, anti-viral activity and phytochemistry of these plants. MATERIALS AND METHODS Peer-reviewed articles investigating plants with ethnobotanical information for the treatment or management of HIV or HIV-related symptoms from the southern African region were acquired from Science Direct, PubMed central and Google Scholar. The selection criteria was that (1) plants should have a record of traditional/popular use for infectious or viral diseases, HIV treatment or symptoms similar to HIV infection, (2) if not traditionally/popularly used, plants should be closely related to plants with popular use and HIV activity identified by means of in vitro assays, (3) plants should have been identified scientifically, (4) should be native to southern African region and (5) anti-HIV activity should be within acceptable ranges. RESULTS Many plants in Africa and specifically the southern African region have been used for the treatment of HIV or HIV related symptoms and have been investigated suing various in vitro techniques. In vitro assays using HIV enzymes such as reverse transcriptase (RT), integrase (IN) and protease (PR), proteins or cell-based assays have been employed to validate the use of these plants with occasional indication of the selectivity index (SI) or therapeutic index (TI), with only one study, that progressed to in vivo testing. The compounds identified from plants from southern Africa is similar to compounds identified from other regions of the world, and the compounds have been divided into three groups namely (1) flavonoids and flavonoid glycosides, (2) terpenoids and terpenoid glycosides and (3) phenolic acids and their conjugated forms. CONCLUSIONS An investigation of the plants from southern Africa with ethnobotanical use for the treatment of HIV, management of HIV or HIV-related symptoms, therefore provide a very good analysis of the major assays employed and the anti-viral compounds and compound groups identified. The similarity in identified anti-viral compounds worldwide should support the progression from in vitro studies to in vivo testing in development of affordable and effective anti-HIV agents for countries with high infection and mortality rates due to HIV/AIDS.
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Affiliation(s)
- Gerhard Prinsloo
- Department of Agriculture and Animal health, University of South Africa (UNISA), Florida Campus, Florida 1710, South Africa.
| | - Cynthia K Marokane
- Department of Agriculture and Animal health, University of South Africa (UNISA), Florida Campus, Florida 1710, South Africa.
| | - Renée A Street
- Environment and Health Research Unit, South African Medical Research Council, Durban 4041, South Africa; Department of Occupational and Environmental Health, University of KwaZulu-Natal, Durban 4001, South Africa.
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16
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Vermeirssen ELM, Dietschweiler C, Werner I, Burkhardt M. Corrosion protection products as a source of bisphenol A and toxicity to the aquatic environment. WATER RESEARCH 2017; 123:586-593. [PMID: 28704774 DOI: 10.1016/j.watres.2017.07.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/27/2017] [Accepted: 07/02/2017] [Indexed: 05/17/2023]
Abstract
Steel components are typically treated with anti-corrosion coatings like epoxy or polyurethane resins to protect the integrity and functioning of steel. Such resins may contain substances, such as bisphenol A (BPA), that have caused concern in a human and environmental toxicological context. We investigated the release of toxicity from four anti-corrosion coatings used in hydraulic and civil engineering. Resins were applied onto glass plates and leachate samples produced by horizontally shaking the plates in water for 7 days. Two experiments were conducted, one with a 1 day and one with a 7 day curing period. Using a suite of bioassays, we tested samples for: agonistic and antagonistic effects on various mammalian nuclear receptors; inhibition of photosynthesis and growth in algae; inhibition of bacterial bioluminescence; and inhibition of water flea reproduction. Concentrations of BPA, bisphenol F and various BPA transformation products were determined by chemical analysis (LC-MS/MS). Bioassay results were evaluated using a scheme developed by DIBt (Centre of Competence for Construction, Berlin, Germany). Three products induced responses in one or more of the measured endpoints and toxicity profiles varied markedly in intensity across products. One product released high amounts of BPA which was associated with effects on nuclear receptor transactivation, requiring a more than 700-fold dilution for effect induction to fall below 20%. The same product was also the most toxic to water flea reproduction, requiring ca. 70-fold dilution for effects to fall below 20%. Another product was highly toxic in terms of bacterial bioluminescence, particularly after a shorter curing time, requiring a ca. 1'300-fold dilution for effects to fall below 20%. The third product required a 22-fold dilution for inhibition of water flea reproduction to drop below 20%. Results show that anti-corrosion coatings based on epoxy resins can be a source of toxicity to the aquatic environment. The fact that some products are more toxic than others highlights opportunities for the development of low risk formulations and products with better environmental performance. Finally, the DIBt scheme provides a useful starting point to develop further ecotoxicity guidelines for testing and data evaluation of leachates from construction materials.
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Affiliation(s)
| | - Conrad Dietschweiler
- HSR University of Applied Sciences, Institute of Environmental and Process Engineering (UMTEC), 8640 Rapperswil, Switzerland
| | - Inge Werner
- Swiss Centre for Applied Ecotoxicology Eawag-EPFL, 8600 Dübendorf, Switzerland
| | - Michael Burkhardt
- HSR University of Applied Sciences, Institute of Environmental and Process Engineering (UMTEC), 8640 Rapperswil, Switzerland
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17
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Tarnow P, Bross S, Wollenberg L, Nakajima Y, Ohmiya Y, Tralau T, Luch A. A Novel Dual-Color Luciferase Reporter Assay for Simultaneous Detection of Estrogen and Aryl Hydrocarbon Receptor Activation. Chem Res Toxicol 2017; 30:1436-1447. [DOI: 10.1021/acs.chemrestox.7b00076] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Patrick Tarnow
- German Federal Institute for Risk Assessment, Department
of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Steffi Bross
- German Federal Institute for Risk Assessment, Department
of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Lisa Wollenberg
- German Federal Institute for Risk Assessment, Department
of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Yoshihiro Nakajima
- Health
Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan
| | - Yoshihiro Ohmiya
- DAILAB,
Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Tewes Tralau
- German Federal Institute for Risk Assessment, Department
of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Andreas Luch
- German Federal Institute for Risk Assessment, Department
of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
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18
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Prinsloo G, Papadi G, Hiben MG, de Haan L, Louisse J, Beekmann K, Vervoort J, Rietjens IMCM. In vitro bioassays to evaluate beneficial and adverse health effects of botanicals: promises and pitfalls. Drug Discov Today 2017; 22:1187-1200. [PMID: 28533190 DOI: 10.1016/j.drudis.2017.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 04/24/2017] [Accepted: 05/09/2017] [Indexed: 01/05/2023]
Abstract
This review provides an update on the promises and pitfalls when using in vitro bioassays to evaluate beneficial and adverse health effects of botanicals and botanical preparations. Important issues addressed in the paper are: (i) the type of assays and biological effects available; (ii) false-positives, false-negatives and confounding factors; (iii) matrix and combination effects; (iv) extrapolation of in vitro data to the in vivo situation; (v) when (not) to use bioassays; and (vi) identification of active constituents. It is concluded that in vitro bioassays provide models to detect beneficial as well as adverse activities, but that linking these observations to individual ingredients and extrapolations to the in vivo situation is more complicated than generally anticipated.
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Affiliation(s)
- Gerhard Prinsloo
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands; Department of Agriculture and Animal Health, University of South Africa, Private bag x 6, Florida, South Africa.
| | - Georgia Papadi
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands; Department of Biological Applications & Technology, University of Ioannina, Greece
| | - Mebrahtom G Hiben
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands; Department of Pharmacognosy, School of Pharmacy, College of Health Sciences, Mekelle University, Mekelle, Ethiopia
| | - Laura de Haan
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Jochem Louisse
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Karsten Beekmann
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Jacques Vervoort
- Department of Agriculture and Animal Health, University of South Africa, Private bag x 6, Florida, South Africa; Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
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19
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Procházková T, Sychrová E, Javůrková B, Večerková J, Kohoutek J, Lepšová-Skácelová O, Bláha L, Hilscherová K. Phytoestrogens and sterols in waters with cyanobacterial blooms - Analytical methods and estrogenic potencies. CHEMOSPHERE 2017; 170:104-112. [PMID: 27974267 DOI: 10.1016/j.chemosphere.2016.12.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 11/27/2016] [Accepted: 12/02/2016] [Indexed: 06/06/2023]
Abstract
Compounds with estrogenic potencies and their adverse effects in surface waters have received much attention. Both anthropogenic and natural compounds contribute to overall estrogenic activity in freshwaters. Recently, estrogenic potencies were also found to be associated with cyanobacteria and their blooms in surface waters. The present study developed and compared the solid phase extraction and LC-MS/MS analytical approaches for determination of phytoestrogens (8 flavonoids - biochanin A, coumestrol, daidzein, equol, formononetin, genistein, naringenin, apigenin - and 5 sterols - ergosterol, β-sitosterol, stigmasterol, campesterol, brassicasterol) and cholesterol in water. The method was used for analyses of samples collected in stagnant water bodies dominated by different cyanobacterial species. Concentrations of individual flavonoids ranged from below the limit of detection to 3.58 ng/L. Sterols were present in higher amounts up to 2.25 μg/L. Biological potencies of these phytoestrogens in vitro were characterized using the hERα-HeLa-9903 cell line. The relative estrogenic potencies (compared to model estrogen - 17β-estradiol) of flavonoids ranged from 2.25E-05 to 1.26E-03 with coumestrol being the most potent. None of the sterols elicited estrogenic response in the used bioassay. Estrogenic activity was detected in collected field water samples (maximum effect corresponding to 2.07 ng/L of 17β-estradiol equivalents, transcriptional assay). At maximum phytoestrogens accounted for only 1.56 pg/L of 17β-estradiol equivalents, contributing maximally 8.5% of the total estrogenicity of the water samples. Other compounds therefore, most likely of anthropogenic origin such as steroid estrogens, are probably the major drivers of total estrogenic effects in these surface waters.
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Affiliation(s)
- Tereza Procházková
- RECETOX - Research Centre for Toxic Compounds in the Environment, Masaryk University, Faculty of Science, Brno, Czech Republic
| | - Eliška Sychrová
- RECETOX - Research Centre for Toxic Compounds in the Environment, Masaryk University, Faculty of Science, Brno, Czech Republic
| | - Barbora Javůrková
- RECETOX - Research Centre for Toxic Compounds in the Environment, Masaryk University, Faculty of Science, Brno, Czech Republic
| | - Jaroslava Večerková
- RECETOX - Research Centre for Toxic Compounds in the Environment, Masaryk University, Faculty of Science, Brno, Czech Republic
| | - Jiří Kohoutek
- RECETOX - Research Centre for Toxic Compounds in the Environment, Masaryk University, Faculty of Science, Brno, Czech Republic
| | - Olga Lepšová-Skácelová
- Department of Botany, University of South Bohemia, Faculty of Science, České Budějovice, Czech Republic
| | - Luděk Bláha
- RECETOX - Research Centre for Toxic Compounds in the Environment, Masaryk University, Faculty of Science, Brno, Czech Republic
| | - Klára Hilscherová
- RECETOX - Research Centre for Toxic Compounds in the Environment, Masaryk University, Faculty of Science, Brno, Czech Republic.
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20
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Lehmann C, Sieg H, Lampen A, Braeuning A. Disturbance of firefly luciferase-based bioassays by different aluminum species. Anal Biochem 2016; 504:27-9. [PMID: 27059752 DOI: 10.1016/j.ab.2016.03.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 03/11/2016] [Accepted: 03/28/2016] [Indexed: 10/22/2022]
Abstract
Luciferase-dependent assays, important for biochemical analyses of cytotoxicity and reporter genes, may be perturbed by compounds interfering with the luciferase reaction. We analyzed the impact of different aluminum (Al) species on a luciferase-based assay for determination of cellular adenosine triphosphate. Al(0) nanoparticles (Al(0)-NPs) but not Al2O3-NPs decreased luminescence, correlated to high absorbance of Al(0)-NPs. By contrast, Al ions increased the luminescent signal. Data demonstrate that luciferase-dependent assays can be reciprocally disturbed by Al-NPs or Al ions in a specific manner, depending on the particular Al species. Careful interpretation of data from such experiments is essential in order to obtain conclusive results.
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Affiliation(s)
- Caroline Lehmann
- Department of Food Safety, Federal Institute for Risk Assessment, 10589 Berlin, Germany
| | - Holger Sieg
- Department of Food Safety, Federal Institute for Risk Assessment, 10589 Berlin, Germany
| | - Alfonso Lampen
- Department of Food Safety, Federal Institute for Risk Assessment, 10589 Berlin, Germany
| | - Albert Braeuning
- Department of Food Safety, Federal Institute for Risk Assessment, 10589 Berlin, Germany.
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21
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Seeger B, Klawonn F, Nguema Bekale B, Steinberg P. Mixture Effects of Estrogenic Pesticides at the Human Estrogen Receptor α and β. PLoS One 2016; 11:e0147490. [PMID: 26812056 PMCID: PMC4728068 DOI: 10.1371/journal.pone.0147490] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 01/05/2016] [Indexed: 11/18/2022] Open
Abstract
Consumers of fruits and vegetables are frequently exposed to small amounts of hormonally active pesticides, some of them sharing a common mode of action such as the activation of the human estrogen receptor α (hERα) or β (hERβ). Therefore, it is of particular importance to evaluate risks emanating from chemical mixtures, in which the individual pesticides are present at human-relevant concentrations, below their corresponding maximum residue levels. Binary and ternary iso-effective mixtures of estrogenic pesticides at effect concentrations eliciting a 1 or 10% effect in the presence or absence of 17β-estradiol were tested experimentally at the hERα in the yeast-based estrogen screen (YES) assay as well as in the human U2-OS cell-based ERα chemical-activated luciferase gene expression (ERα CALUX) assay and at the hERβ in the ERβ CALUX assay. The outcome was then compared to predictions calculated by means of concentration addition. In most cases, additive effects were observed with the tested combinations in all three test systems, an observation that supports the need to expand the risk assessment of pesticides and consider cumulative risk assessment. An additional testing of mixture effects at the hERβ showed that most test substances being active at the hERα could also elicit additive effects at the hERβ, but the hERβ was less sensitive. In conclusion, effects of the same ligands at the hERα and the hERβ could influence the estrogenic outcome under physiological conditions.
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Affiliation(s)
- Bettina Seeger
- Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173, Hannover, Germany
| | - Frank Klawonn
- Biostatistics Group, Helmholtz Centre for Infection Research, Inhoffenstr. 7, 38124, Braunschweig, Germany
- Department of Computer Science, Ostfalia University of Applied Sciences, Salzdahlumerstr. 46/48, 38302, Wolfenbüttel, Germany
| | - Boris Nguema Bekale
- Department of Computer Science, Ostfalia University of Applied Sciences, Salzdahlumerstr. 46/48, 38302, Wolfenbüttel, Germany
| | - Pablo Steinberg
- Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173, Hannover, Germany
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22
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Wielogórska E, Elliott CT, Danaher M, Connolly L. Endocrine disruptor activity of multiple environmental food chain contaminants. Toxicol In Vitro 2015; 29:211-20. [PMID: 25449125 DOI: 10.1016/j.tiv.2014.10.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 10/15/2014] [Accepted: 10/17/2014] [Indexed: 01/08/2023]
Abstract
Industrial chemicals, antimicrobials, drugs and personal care products have been reported as global pollutants which enter the food chain. Some of them have also been classified as endocrine disruptors based on results of various studies employing a number of in vitro/vivo tests. The present study employed a mammalian reporter gene assay to assess the effects of known and emerging contaminants on estrogen nuclear receptor transactivation. Out of fifty-nine compounds assessed, estrogen receptor agonistic activity was observed for parabens( n = 3), UV filters (n = 6), phthalates (n = 4) and a metabolite, pyrethroids (n = 9) and their metabolites (n = 3). Two compounds were estrogen receptor antagonists while some of the agonists enhanced 17b-estradiol mediated response.This study reports five new compounds (pyrethroids and their metabolites) possessing estrogen agonist activity and highlights for the first time that pyrethroid metabolites are of particular concern showing much greater estrogenic activity than their parent compounds.
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Affiliation(s)
- E Wielogórska
- Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Northern Ireland, United Kingdom
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Islam MA, Bekele R, Vanden Berg JHJ, Kuswanti Y, Thapa O, Soltani S, van Leeuwen FXR, Rietjens IMCM, Murk AJ. Deconjugation of soy isoflavone glucuronides needed for estrogenic activity. Toxicol In Vitro 2015; 29:706-15. [PMID: 25661160 DOI: 10.1016/j.tiv.2015.01.013] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 01/17/2015] [Accepted: 01/26/2015] [Indexed: 10/24/2022]
Abstract
Soy isoflavones (SIF) are present in the systemic circulation as conjugated forms of which the estrogenic potency is not yet clear. The present study provides evidence that the major SIF glucuronide metabolites in blood, genistein-7-O-glucuronide (GG) and daidzein-7-O-glucuronide (DG), only become estrogenic after deconjugation. The estrogenic potencies of genistein (Ge), daidzein (Da), GG and DG were determined using stably transfected U2OS-ERα, U2OS-ERβ reporter gene cells and proliferation was tested in T47D-ERβ cells mimicking the ERα/ERβ ratio of healthy breast cells and inT47D breast cancer cells. In all assays applied, the estrogenic potency of the aglycones was significantly higher than that of their corresponding glucuronides. UPLC analysis revealed that in U2OS and T47D cells, 0.2-1.6% of the glucuronides were deconjugated to their corresponding aglycones. The resulting aglycone concentrations can account for the estrogenicity observed upon glucuronide exposure. Interestingly, under similar experimental conditions, rat breast tissue S9 fraction was about 30 times more potent in deconjugating these glucuronides than human breast tissue S9 fraction. Our study confirms that SIF glucuronides are not estrogenic as such, and that the small % of deconjugation in the cell is enough to explain the slight bioactivity observed for the SIF-glucuronides. Species differences in deconjugation capacity should be taken into account when basing risk-benefit assessment of these SIF for the human population on animal data.
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Affiliation(s)
- M A Islam
- Division of Toxicology, Wageningen University, 6703 HE Wageningen, The Netherlands.
| | - R Bekele
- Division of Toxicology, Wageningen University, 6703 HE Wageningen, The Netherlands
| | - J H J Vanden Berg
- Division of Toxicology, Wageningen University, 6703 HE Wageningen, The Netherlands
| | - Y Kuswanti
- Division of Toxicology, Wageningen University, 6703 HE Wageningen, The Netherlands
| | - O Thapa
- Division of Toxicology, Wageningen University, 6703 HE Wageningen, The Netherlands
| | - S Soltani
- Division of Toxicology, Wageningen University, 6703 HE Wageningen, The Netherlands
| | - F X R van Leeuwen
- Division of Toxicology, Wageningen University, 6703 HE Wageningen, The Netherlands
| | - I M C M Rietjens
- Division of Toxicology, Wageningen University, 6703 HE Wageningen, The Netherlands
| | - A J Murk
- Division of Toxicology, Wageningen University, 6703 HE Wageningen, The Netherlands
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24
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Structural bisphenol analogues differentially target steroidogenesis in murine MA-10 Leydig cells as well as the glucocorticoid receptor. Toxicology 2015; 329:10-20. [DOI: 10.1016/j.tox.2015.01.003] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 01/05/2015] [Accepted: 01/05/2015] [Indexed: 12/20/2022]
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25
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Islam MA, Hooiveld GJEJ, van den Berg JHJ, Boekschoten MV, van der Velpen V, Murk AJ, Rietjens IMCM, van Leeuwen FXR. Plasma bioavailability and changes in PBMC gene expression after treatment of ovariectomized rats with a commercial soy supplement. Toxicol Rep 2015; 2:308-321. [PMID: 28962364 PMCID: PMC5598277 DOI: 10.1016/j.toxrep.2014.12.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 12/18/2014] [Accepted: 12/18/2014] [Indexed: 11/02/2022] Open
Abstract
The health effects of soy supplementation in (post)menopausal women are still a controversial issue. The aim of the present study was to establish the effect of the soy isoflavones (SIF) present in a commercially available supplement on ovariectomized rats and to investigate whether these rats would provide an adequate model to predict effects of SIF in (post)menopausal women. Two dose levels (i.e. 2 and 20 mg/kg b.w.) were used to characterize plasma bioavailability, urinary and fecal concentrations of SIF and changes in gene expression in peripheral blood mononuclear cells (PBMC). Animals were dosed at 0 and 48 h and sacrificed 4 h after the last dose. A clear dose dependent increase of SIF concentrations in plasma, urine and feces was observed, together with a strong correlation in changes in gene expression between the two dose groups. All estrogen responsive genes and related biological pathways (BPs) that were affected by the SIF treatment were regulated in both dose groups in the same direction and indicate beneficial effects. However, in general no correlation was found between the changes in gene expression in rat PBMC with those in PBMC of (post)menopausal women exposed to a comparable dose of the same supplement. The outcome of this short-term study in rats indicates that the rat might not be a suitable model to predict effects of SIF in humans. Although the relative exposure period in this rat study is comparable with that of the human study, longer repetitive administration of rats to SIF may be required to draw a final conclusion on the suitability of the rat a model to predict effects of SIF in humans.
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Key Words
- BPs, biological pathways
- Bioavailability
- DMSO, dimethyl sulfoxide
- Dose effect
- E2, estradiol
- ECM, extracellular matrix
- EREs, estrogen-responsive elements
- ERs, estrogen receptors
- GSEA, gene set enrichment analysis
- Gene expression
- HD, high dose
- HPLC, high performance liquid chromatography
- KEGG, kyoto encyclopedia of genes and genomes
- LD, low dose
- MDS, multidimensional scaling
- NCBI, National Center for Biotechnology Information
- PBMC, peripheral blood mononuclear cells
- SIF, soy isoflavones
- Soy supplementation
- Species differences
- UPC, universal expression code
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Affiliation(s)
- Mohammed A Islam
- Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE Wageningen, The Netherlands
| | - Guido J E J Hooiveld
- Division of Human Nutrition, Wageningen University, Bomenweg 2, 6703 HE Wageningen, The Netherlands
| | | | - Mark V Boekschoten
- Division of Human Nutrition, Wageningen University, Bomenweg 2, 6703 HE Wageningen, The Netherlands
| | - Vera van der Velpen
- Division of Human Nutrition, Wageningen University, Bomenweg 2, 6703 HE Wageningen, The Netherlands.,Department of Nutrition, Norwich Medical School, University of East Anglia, Norwich, UK
| | - Albertinka J Murk
- Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE Wageningen, The Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE Wageningen, The Netherlands
| | - F X Rolaf van Leeuwen
- Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE Wageningen, The Netherlands
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26
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Beekmann K, Rubió L, de Haan LHJ, Actis-Goretta L, van der Burg B, van Bladeren PJ, Rietjens IMCM. The effect of quercetin and kaempferol aglycones and glucuronides on peroxisome proliferator-activated receptor-gamma (PPAR-γ). Food Funct 2015; 6:1098-107. [DOI: 10.1039/c5fo00076a] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Quercetin and kaempferol increase PPAR-γ mediated gene expression without acting as agonistic ligands; glucuronidation reduces their activity in cell-based assays.
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Affiliation(s)
- Karsten Beekmann
- Division of Toxicology
- Wageningen University
- 6700EA Wageningen
- The Netherlands
| | - Laura Rubió
- Department of Food Technology
- XaRTA-UTPV
- Escola Tècnica Superior d'Enginyeria Agrària
- Universitat de Lleida
- 25198 Lleida
| | | | | | | | - Peter J. van Bladeren
- Division of Toxicology
- Wageningen University
- 6700EA Wageningen
- The Netherlands
- Nestlé Research Center
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27
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Sun S, Choi YH, Na CS, Lee D, Yoo HH, Hong CY, Ahn BY, Dong MS. Estrogenic activity of a Rhus verniciflua extract and its major components. J Funct Foods 2014. [DOI: 10.1016/j.jff.2014.09.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Simon A, Maletz SX, Hollert H, Schäffer A, Maes HM. Effects of multiwalled carbon nanotubes and triclocarban on several eukaryotic cell lines: elucidating cytotoxicity, endocrine disruption, and reactive oxygen species generation. NANOSCALE RESEARCH LETTERS 2014; 9:396. [PMID: 25170332 PMCID: PMC4142056 DOI: 10.1186/1556-276x-9-396] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 08/09/2014] [Indexed: 05/23/2023]
Abstract
To date, only a few reports about studies on toxic effects of carbon nanotubes (CNT) are available, and their results are often controversial. Three different cell lines (rainbow trout liver cells (RTL-W1), human adrenocortical carcinoma cells (T47Dluc), and human adrenocarcinoma cells (H295R)) were exposed to multiwalled carbon nanotubes, the antimicrobial agent triclocarban (TCC) as well as the mixture of both substances in a concentration range of 3.13 to 50 mg CNT/L, 31.25 to 500 μg TCC/L, and 3.13 to 50 mg CNT/L + 1% TCC (percentage relative to carbon nanotubes concentration), respectively. Triclocarban is a high-production volume chemical that is widely used as an antimicrobial compound and is known for its toxicity, hydrophobicity, endocrine disruption, bioaccumulation potential, and environmental persistence. Carbon nanotubes are known to interact with hydrophobic organic compounds. Therefore, triclocarban was selected as a model substance to examine mixture toxicity in this study. The influence of multiwalled carbon nanotubes and triclocarban on various toxicological endpoints was specified: neither cytotoxicity nor endocrine disruption could be observed after exposure of the three cell lines to carbon nanotubes, but the nanomaterial caused intracellular generation of reactive oxygen species in all cell types. For TCC on the other hand, cell vitality of 80% could be observed at a concentration of 2.1 mg/L for treated RTL-W1 cells. A decrease of luciferase activity in the ER Calux assay at a triclocarban concentration of 125 μg/L and higher was observed. This effect was less pronounced when multiwalled carbon nanotubes were present in the medium. Taken together, these results demonstrate that multiwalled carbon nanotubes induce the production of reactive oxygen species in RTL-W1, T47Dluc, and H295R cells, reveal no cytotoxicity, and reduce the bioavailability and toxicity of the biocide triclocarban.
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Affiliation(s)
- Anne Simon
- Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, Aachen 52074, Germany
| | - Sibylle X Maletz
- Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, Aachen 52074, Germany
| | - Henner Hollert
- Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, Aachen 52074, Germany
- School of Environment, Nanjing University, Nanjing 210023, China
- Key Laboratory of Yangtze River Environment of Education Ministry of China, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- College of Resources and Environmental Science, Chongqing University, Chongqing 400715, China
| | - Andreas Schäffer
- Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, Aachen 52074, Germany
- School of Environment, Nanjing University, Nanjing 210023, China
- Key Laboratory of Yangtze River Environment of Education Ministry of China, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- College of Resources and Environmental Science, Chongqing University, Chongqing 400715, China
| | - Hanna M Maes
- Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, Aachen 52074, Germany
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29
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Wielogorska E, Elliott C, Danaher M, Connolly L. Validation and application of a reporter gene assay for the determination of estrogenic endocrine disruptor activity in milk. Food Chem Toxicol 2014; 69:260-6. [DOI: 10.1016/j.fct.2014.04.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 03/23/2014] [Accepted: 04/15/2014] [Indexed: 11/30/2022]
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30
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Wang S, Rijk JCW, Besselink HT, Houtman R, Peijnenburg AACM, Brouwer A, Rietjens IMCM, Bovee TFH. Extending an in vitro panel for estrogenicity testing: the added value of bioassays for measuring antiandrogenic activities and effects on steroidogenesis. Toxicol Sci 2014; 141:78-89. [PMID: 24928889 DOI: 10.1093/toxsci/kfu103] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In the present study, a previously established integrated testing strategy (ITS) for in vitro estrogenicity testing was extended with additional in vitro assays in order to broaden its sensitivity to different modes of action resulting in apparent estrogenicity, i.e., other than estrogen receptor (ER) binding. To this end, an extra set of 10 estrogenic compounds with modes of action in part different from ER binding, were tested in the previously defined ITS, consisting of a yeast estrogen reporter gene assay, an U2OS ERα CALUX reporter gene assay and a cell-free coregulator binding assay. Two androgen reporter gene assays and the enhanced H295R steroidogenesis assay were added to that previous defined ITS. These assays had added value, as several estrogenic model compounds also elicited clear and potent antiandrogenic properties and in addition also showed effects on steroidogenesis that might potentiate their apparent estrogenic effects in vivo. Adding these assays, examining mechanisms of action for estrogenicity apart from ERα binding, gives a more complete and comprehensive assessment of the ability of test compounds to interfere with endocrine signaling. It was concluded that the extended ITS will go beyond in vivo estrogenicity testing by the uterotrophic assay, thereby contributing to the 3R-principles.
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Affiliation(s)
- Si Wang
- Division of Toxicology, Wageningen University and Research Centre, Tuinlaan 5, 6703 HE Wageningen, The Netherlands Business Unit of Toxicology & Bioassays, RIKILT - Institute of Food Safety, Wageningen University and Research Centre, Akkermaalsbos 2, 6708 WB Wageningen, The Netherlands
| | - Jeroen C W Rijk
- Business Unit of Toxicology & Bioassays, RIKILT - Institute of Food Safety, Wageningen University and Research Centre, Akkermaalsbos 2, 6708 WB Wageningen, The Netherlands
| | - Harrie T Besselink
- BioDetection Systems B.V., Science Park 406, 1098 XH Amsterdam, The Netherlands
| | - René Houtman
- PamGene International B.V., Wolvenhoek 10, 5211 HH 's-Hertogenbosch, The Netherlands
| | - Ad A C M Peijnenburg
- Business Unit of Toxicology & Bioassays, RIKILT - Institute of Food Safety, Wageningen University and Research Centre, Akkermaalsbos 2, 6708 WB Wageningen, The Netherlands
| | - Abraham Brouwer
- BioDetection Systems B.V., Science Park 406, 1098 XH Amsterdam, The Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University and Research Centre, Tuinlaan 5, 6703 HE Wageningen, The Netherlands
| | - Toine F H Bovee
- Business Unit of Toxicology & Bioassays, RIKILT - Institute of Food Safety, Wageningen University and Research Centre, Akkermaalsbos 2, 6708 WB Wageningen, The Netherlands
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31
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Larsson M, Hagberg J, Giesy JP, Engwall M. Time-dependent relative potency factors for polycyclic aromatic hydrocarbons and their derivatives in the H4IIE-luc bioassay. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2014; 33:943-53. [PMID: 24408822 DOI: 10.1002/etc.2517] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 09/24/2013] [Accepted: 01/03/2014] [Indexed: 05/07/2023]
Abstract
The H4IIE-luc transactivation bioassay for aryl hydrocarbon receptor (AhR) agonists was used to investigate the relative potency factors (REPs) of 22 individual polycyclic aromatic hydrocarbons (PAHs) and their oxygenated-, methylated-, and N-containing derivatives (azaarenes), which are often present in PAH-contaminated soils. Naphthacene and dibenz[ah]acridine exhibited greater AhR-mediated potency, whereas lesser molecular-weight azaarenes were less potent AhR agonists. Six oxygenated PAHs had calculable REPs, but their potencies were less than their parent PAHs. Unlike the parent, unsubstituted PAHs, oxidation of methylated PAHs seemed to increase the AhR-mediated potency of the compounds, with 2-methylanthracene-9,10-dione being almost 2 times more potent than 2-methylanthracene. Both bioassay and gas chromatography-mass spectrometry analysis were used to examine the exposure time-dependent effects on the REPs at 24 h, 48 h, and 72 h of exposure in the H4IIE-luc transactivation bioassay. Changes in concentrations of 5 compounds including the model reference 2,3,7,8-tetrachlorodibenzo-p-dioxin in the cell culture wells were measured, and the amounts in the cell medium, in the cells, and adsorbed to the wells was determined and the influence on the REPs was studied. Declining REP values with increased duration of exposure were shown for all compounds, which we concluded were a consequence of the metabolism of PAHs and PAH derivatives in H4IIe-luc cells. The present study provides new knowledge regarding the degradation and distribution of compounds in the wells during exposure.
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Affiliation(s)
- Maria Larsson
- Man-Technology-Environment Research Centre, School of Science and Technology, Örebro University, Örebro, Sweden
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32
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Leusch FDL, Khan SJ, Laingam S, Prochazka E, Froscio S, Trinh T, Chapman HF, Humpage A. Assessment of the application of bioanalytical tools as surrogate measure of chemical contaminants in recycled water. WATER RESEARCH 2014; 49:300-15. [PMID: 24355290 DOI: 10.1016/j.watres.2013.11.030] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 11/15/2013] [Accepted: 11/18/2013] [Indexed: 05/08/2023]
Abstract
The growing use of recycled water in large urban centres requires comprehensive public health risk assessment and management, an important aspect of which is the assessment and management of residual trace chemical substances. Bioanalytical methods such as in vitro bioassays may be ideal screening tools that can detect a wide range of contaminants based on their biological effect. In this study, we applied thirteen in vitro assays selected explicitly for their ability to detect molecular and cellular effects relevant to potential chemical exposure via drinking water as a means of screening for chemical contaminants from recycled water at 9 Australian water reclamation plants, in parallel to more targeted direct chemical analysis of 39 priority compounds. The selected assays provided measures of primary non-specific (cytotoxicity to various cell types), specific (inhibition of acetylcholinesterase and endocrine receptor-mediated effects) and reactive toxicity (mutagenicity and genotoxicity), as well as markers of adaptive stress response (modulation of cytokine production) and xenobiotic metabolism (liver enzyme induction). Chemical and bioassay analyses were in agreement and complementary to each other: the results show that source water (treated wastewater) contained high levels of biologically active compounds, with positive results in almost all bioassays. The quality of the product water (reclaimed water) was only marginally better after ultrafiltration or dissolved air floatation/filtration, but greatly improved after reverse osmosis often reducing biological activity to below detection limit. The bioassays were able to detect activity at concentrations below current chemical method detection limits and provided a sum measure of all biologically active compounds for that bioassay, thus providing an additional degree of confidence in water quality.
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Affiliation(s)
- Frederic D L Leusch
- Smart Water Research Centre, Griffith University Gold Coast Campus, Southport, Qld 4222, Australia.
| | - Stuart J Khan
- Water Research Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | | | - Erik Prochazka
- Smart Water Research Centre, Griffith University Gold Coast Campus, Southport, Qld 4222, Australia
| | - Suzanne Froscio
- Australian Water Quality Centre, SA Water, Adelaide, SA 5001, Australia
| | - Trang Trinh
- Water Research Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | - Heather F Chapman
- Smart Water Research Centre, Griffith University Gold Coast Campus, Southport, Qld 4222, Australia
| | - Andrew Humpage
- Australian Water Quality Centre, SA Water, Adelaide, SA 5001, Australia
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Wang S, Aarts JMMJG, de Haan LHJ, Argyriou D, Peijnenburg AACM, Rietjens IMCM, Bovee TFH. Towards an integratedin vitrostrategy for estrogenicity testing. J Appl Toxicol 2013; 34:1031-40. [DOI: 10.1002/jat.2928] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 07/11/2013] [Accepted: 08/04/2013] [Indexed: 12/30/2022]
Affiliation(s)
- Si Wang
- Division of Toxicology; Wageningen University and Research Centre; Tuinlaan 5 6703 HE Wageningen The Netherlands
- Business Unit of Toxicology & Bioassays, RIKILT - Institute of Food Safety; Wageningen University and Research Centre; Akkermaalsbos 2 6708 WB Wageningen The Netherlands
| | - Jac M. M. J. G. Aarts
- Business Unit of Toxicology & Bioassays, RIKILT - Institute of Food Safety; Wageningen University and Research Centre; Akkermaalsbos 2 6708 WB Wageningen The Netherlands
| | - Laura H. J. de Haan
- Division of Toxicology; Wageningen University and Research Centre; Tuinlaan 5 6703 HE Wageningen The Netherlands
| | - Dimitrios Argyriou
- Division of Toxicology; Wageningen University and Research Centre; Tuinlaan 5 6703 HE Wageningen The Netherlands
| | - Ad A. C. M. Peijnenburg
- Business Unit of Toxicology & Bioassays, RIKILT - Institute of Food Safety; Wageningen University and Research Centre; Akkermaalsbos 2 6708 WB Wageningen The Netherlands
| | - Ivonne M. C. M. Rietjens
- Division of Toxicology; Wageningen University and Research Centre; Tuinlaan 5 6703 HE Wageningen The Netherlands
| | - Toine F. H. Bovee
- Business Unit of Toxicology & Bioassays, RIKILT - Institute of Food Safety; Wageningen University and Research Centre; Akkermaalsbos 2 6708 WB Wageningen The Netherlands
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Brand W, de Jongh CM, van der Linden SC, Mennes W, Puijker LM, van Leeuwen CJ, van Wezel AP, Schriks M, Heringa MB. Trigger values for investigation of hormonal activity in drinking water and its sources using CALUX bioassays. ENVIRONMENT INTERNATIONAL 2013; 55:109-18. [PMID: 23542573 DOI: 10.1016/j.envint.2013.02.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 01/25/2013] [Accepted: 02/16/2013] [Indexed: 05/20/2023]
Abstract
To screen for hormonal activity in water samples, highly sensitive in vitro CALUX bioassays are available which allow detection of estrogenic (ERα), androgenic (AR), progestagenic (PR), and glucocorticoid (GR) activities. This paper presents trigger values for the ERα, AR, PR, and GR CALUX bioassays for agonistic hormonal activities in (drinking) water, which define a level above which human health risk cannot be waived a priori and additional examination of specific endocrine activity may be warranted. The trigger values are based on 1) acceptable or tolerable daily intake (ADI/TDI) values of specific compounds, 2) pharmacokinetic factors defining their bioavailability, 3) estimations of the bioavailability of unknown compounds with equivalent hormonal activity, 4) relative endocrine potencies, and 5) physiological, and drinking water allocation factors. As a result, trigger values of 3.8ng 17β-estradiol (E2)-equivalents (eq)/L, 11ng dihydrotestosterone (DHT)-eq/L, 21ng dexamethasone (DEX)-eq/L, and 333ng Org2058-eq/L were derived. Benchmark Quotient (BQ) values were derived by dividing hormonal activity in water samples by the derived trigger using the highest concentrations detected in a recent, limited screening of Dutch water samples, and were in the order of (value) AR (0.41)>ERα (0.13)>GR (0.06)>PR (0.04). The application of trigger values derived in the present study can help to judge measured agonistic hormonal activities in water samples using the CALUX bioassays and help to decide whether further examination of specific endocrine activity followed by a subsequent safety evaluation may be warranted, or whether concentrations of such activity are of low priority with respect to health concerns in the human population. For instance, at one specific drinking water production site ERα and AR (but no GR and PR) activities were detected in drinking water, however, these levels are at least a factor 83 smaller than the respective trigger values, and therefore no human health risks are to be expected from hormonal activity in Dutch drinking water from this site.
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Affiliation(s)
- Walter Brand
- KWR Watercycle Research Institute, Groningenhaven 7, 3433 PE Nieuwegein, The Netherlands.
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35
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Tarnow P, Tralau T, Hunecke D, Luch A. Effects of triclocarban on the transcription of estrogen, androgen and aryl hydrocarbon receptor responsive genes in human breast cancer cells. Toxicol In Vitro 2013; 27:1467-75. [PMID: 23524099 DOI: 10.1016/j.tiv.2013.03.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 03/04/2013] [Accepted: 03/12/2013] [Indexed: 12/20/2022]
Abstract
Triclocarban (TCC) is an antimicrobial agent that is used in detergents, soaps and other personal hygiene products. Similarly to triclosan the widespread use of TCC has raised concerns about its endocrine potential. In luciferase-based reporter assays TCC has been shown to enhance estrogenic and androgenic activities following cellular coexposure with estrogen or dihydrotestosterone, respectively. The present study demonstrates that although coexposure with TCC enhances the estrogenic and androgenic readout of luciferase-based reporter cell lines such as HeLa9908 and MDA-kb2, it fails to act as a xenoandrogen on transcriptional level, nor does it induce cell proliferation in the estrogen sensitive E-screen. In addition TCC did not alter the expression of estrogen responsive genes in human mammary carcinoma MCF-7 cells exposed to 17β-estradiol, bisphenol A, butylparaben or genistein. However, TCC was shown to interfere with the regulon of the aryl hydrocarbon receptor (AhR) as TCC showed a costimulatory effect on transcription of CYP1A1 and CYP1B1, effectively lowering the transcriptional threshold for both genes in the presence of estrogens. It thus seems, that while the induction of the respective luciferase reporter assays by TCC is an unspecific false positive signal caused by luciferase stabilisation, TCC has the potential to interfere with the regulatory crosstalk of the estrogen receptor (ER) and the AhR regulon.
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Affiliation(s)
- Patrick Tarnow
- German Federal Institute for Risk Assessment (BfR), Department of Product Safety, Berlin, Germany.
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36
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In vitro androgen bioassays as a detection method for designer androgens. SENSORS 2013; 13:2148-63. [PMID: 23389345 PMCID: PMC3649408 DOI: 10.3390/s130202148] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 01/22/2013] [Accepted: 01/30/2013] [Indexed: 11/27/2022]
Abstract
Androgens are the class of sex steroids responsible for male sexual characteristics, including increased muscle mass and decreased fat mass. Illicit use of androgen doping can be an attractive option for those looking to enhance sporting performance and/or physical appearance. The use of in vitro bioassays to detect androgens, especially designer or proandrogens, is becoming increasingly important in combating androgen doping associated with nutritional supplements. The nutritional sports supplement market has grown rapidly throughout the past decade. Many of these supplements contain androgens, designer androgens or proandrogens. Many designer or proandrogens cannot be detected by the standard highly-sensitive screening methods such as gas chromatography-mass spectrometry because their chemical structure is unknown. However, in vitro androgen bioassays can detect designer and proandrogens as these assays are not reliant on knowing the chemical structure but instead are based on androgen receptor activation. For these reasons, it may be advantageous to use routine androgen bioassay screening of nutraceutical samples to help curb the increasing problem of androgen doping.
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Effect of combining in vitro estrogenicity data with kinetic characteristics of estrogenic compounds on the in vivo predictive value. Toxicol In Vitro 2013; 27:44-51. [DOI: 10.1016/j.tiv.2012.09.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 09/17/2012] [Accepted: 09/18/2012] [Indexed: 11/23/2022]
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38
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Thorne N, Shen M, Lea WA, Simeonov A, Lovell S, Auld DS, Inglese J. Firefly luciferase in chemical biology: a compendium of inhibitors, mechanistic evaluation of chemotypes, and suggested use as a reporter. ACTA ACUST UNITED AC 2012; 19:1060-72. [PMID: 22921073 DOI: 10.1016/j.chembiol.2012.07.015] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 06/25/2012] [Accepted: 07/19/2012] [Indexed: 12/20/2022]
Abstract
Firefly luciferase (FLuc) is frequently used as a reporter in high-throughput screening assays, owing to the exceptional sensitivity, dynamic range, and rapid measurement that bioluminescence affords. However, interaction of small molecules with FLuc has, to some extent, confounded its use in chemical biology and drug discovery. To identify and characterize chemotypes interacting with FLuc, we determined potency values for 360,864 compounds found in the NIH Molecular Libraries Small Molecule Repository, available in PubChem. FLuc inhibitory activity was observed for 12% of this library with discernible SAR. Characterization of 151 inhibitors demonstrated a variety of inhibition modes, including FLuc-catalyzed formation of multisubstrate adduct enzyme inhibitor complexes. As in some cell-based FLuc reporter assays, compounds acting as FLuc inhibitors yield paradoxical luminescence increases, thus data on compounds acquired from FLuc-dependent assays require careful analysis as described here.
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Affiliation(s)
- Natasha Thorne
- National Center for Advancing Translational Sciences, Bethesda, MD 20892-3370, USA
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Gijsbers L, van Eekelen HD, Nguyen TH, de Haan LH, van der Burg B, Aarts JM, Rietjens IM, Bovy AG. Induction of electrophile-responsive element (EpRE)-mediated gene expression by tomato extracts in vitro. Food Chem 2012; 135:1166-72. [DOI: 10.1016/j.foodchem.2012.05.073] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 05/16/2012] [Accepted: 05/17/2012] [Indexed: 12/31/2022]
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40
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Kang HK, Choi YH, Kwon H, Lee SB, Kim DH, Sung CK, Park YI, Dong MS. Estrogenic/antiestrogenic activities of a Epimedium koreanum extract and its major components: in vitro and in vivo studies. Food Chem Toxicol 2012; 50:2751-9. [DOI: 10.1016/j.fct.2012.05.017] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 04/19/2012] [Accepted: 05/01/2012] [Indexed: 01/26/2023]
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41
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Simons R, Gruppen H, Bovee TFH, Verbruggen MA, Vincken JP. Prenylated isoflavonoids from plants as selective estrogen receptor modulators (phytoSERMs). Food Funct 2012; 3:810-27. [PMID: 22684228 DOI: 10.1039/c2fo10290k] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Isoflavonoids are a class of secondary metabolites, which comprise amongst others the subclasses of isoflavones, isoflavans, pterocarpans and coumestans. Isoflavonoids are abundant in Leguminosae, and many of them can bind to the human estrogen receptor (hER) with affinities similar to or lower than that of estradiol. Dietary intake of these so-called phytoestrogens has been associated with positive effects on menopausal complaints, hormone-related cancers, and osteoporosis. Therefore, phytoestrogens are used as nutraceuticals in functional foods or food supplements. Most of the isoflavonoids show agonistic activity towards both hERα and hERβ, the extent of which is modulated by the substitution pattern of their skeleton (i.e.-OH, -OCH(3)). Interestingly, substitutions consisting of a five-carbon prenyl group often seem to result in an antiestrogenic activity. There is growing evidence that the action of some of these prenylated isoflavonoids is tissue-specific, suggesting that they act like selective estrogen receptor modulators (SERMs), such as the well-known chemically synthesized raloxifene and tamoxifen. These so-called phytoSERMS might have high potential for realizing new food and pharma applications. In this review, the structural features of isoflavonoids (i.e. the kind of skeleton and prenylation (e.g. chain or pyran), position of the prenyl group on the skeleton, and the extent of prenylation (single, double)) are discussed in relation to their estrogenic activity. Anti-estrogenic and SERM activity of isoflavonoids was always associated with prenylation, but these activities did not seem to be confined to one particular kind/position of prenylation or isoflavonoid subclass. Few estrogens with agonistic activity were prenylated, but these were not tested for antagonistic activity; possibly, these molecules will turn out to be phytoSERMs as well. Furthermore, the data on the dietary occurrence, bioavailability and metabolism of prenylated isoflavonoids are discussed.
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Affiliation(s)
- Rudy Simons
- Laboratory of Food Chemistry, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, the Netherlands
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Vrabie CM, Sinnige TL, Murk AJ, Jonker MTO. Effect-directed assessment of the bioaccumulation potential and chemical nature of Ah receptor agonists in crude and refined oils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:1572-1580. [PMID: 22257214 DOI: 10.1021/es2036948] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Recent studies have indicated that in addition to narcosis certain chemicals in crude oils and refined petroleum products may induce specific modes of action, such as aryl hydrocarbon receptor (AhR) agonism. The risks these toxic compounds pose to organisms depend on internal exposure levels, as driven by the chemicals' bioaccumulation potential. Information on this potential however is lacking, as the chemicals' identity mostly is unknown. This study showed that AhR agonists bioaccumulate from oil-spiked sediments into aquatic worms and persist in the worms for at least several weeks. Chemical fractionations of eight pure oils into saturates, aromatics, resins, and asphaltenes (SARA), followed by effect-directed analyses using in vitro reporter gene assays revealed that the agonists predominantly are aromatic and resin-like chemicals. Some of the compounds were easily metabolized in vitro, while others were resistant to biotransformation. HPLC-assisted hydrophobicity profiling subsequently indicated that the AhR-active chemicals had a high to extremely high bioaccumulation potential, considering their estimated logK(ow) values of 4 to >10. Most of the AhR agonism, however, was assigned to compounds with logK(ow) of 5-8. These compounds were present mainly in the mid to high boiling point fractions of the oils (C(14)-C(32) alkane range), which are usually not being considered (the most) toxic in current risk assessment. The fractionations further revealed considerable oil and fraction-dependent antagonism in pure oils and SARA fractions. The results of this study clearly demonstrate that crude oils and refined petroleum products contain numerous compounds that can activate the AhR and which because of their likely persistence and extremely high bioaccumulation potential could be potential PBT (persistent, bioaccumulative and toxic) or vPvB (very persistent and very bioaccumulative) substance candidates. Many chemicals were identified by GC-MS, but the responsible individual compounds could not be exactly identified in the complex mixtures of thousands of compounds. Because this obstructs a classical PBT risk assessment, our results advocate an adapted risk assessment approach for complex mixtures in which low concentrations of very potent compounds are responsible for mixture effects.
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Affiliation(s)
- Cozmina M Vrabie
- Institute for Risk Assessment Sciences, Utrecht University, P.O. Box 80177, 3508 TD Utrecht, The Netherlands
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Plotan M, Elliott CT, Scippo ML, Muller M, Antignac JP, Malone E, Bovee TF, Mitchell S, Connolly L. The application of reporter gene assays for the detection of endocrine disruptors in sport supplements. Anal Chim Acta 2011; 700:34-40. [DOI: 10.1016/j.aca.2010.12.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 12/06/2010] [Accepted: 12/08/2010] [Indexed: 11/27/2022]
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44
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Simons R, Vincken JP, Mol LAM, The SAM, Bovee TFH, Luijendijk TJC, Verbruggen MA, Gruppen H. Agonistic and antagonistic estrogens in licorice root (Glycyrrhiza glabra). Anal Bioanal Chem 2011; 401:305-13. [PMID: 21573846 PMCID: PMC3124641 DOI: 10.1007/s00216-011-5061-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 04/21/2011] [Accepted: 04/25/2011] [Indexed: 01/06/2023]
Abstract
The roots of licorice (Glycyrrhiza glabra) are a rich source of flavonoids, in particular, prenylated flavonoids, such as the isoflavan glabridin and the isoflavene glabrene. Fractionation of an ethyl acetate extract from licorice root by centrifugal partitioning chromatography yielded 51 fractions, which were characterized by liquid chromatography-mass spectrometry and screened for activity in yeast estrogen bioassays. One third of the fractions displayed estrogenic activity towards either one or both estrogen receptors (ERs; ERα and ERβ). Glabrene-rich fractions displayed an estrogenic response, predominantly to the ERα. Surprisingly, glabridin did not exert agonistic activity to both ER subtypes. Several fractions displayed higher responses than the maximum response obtained with the reference compound, the natural hormone 17β-estradiol (E(2)). The estrogenic activities of all fractions, including this so-called superinduction, were clearly ER-mediated, as the estrogenic response was inhibited by 20-60% by known ER antagonists, and no activity was found in yeast cells that did not express the ERα or ERβ subtype. Prolonged exposure of the yeast to the estrogenic fractions that showed superinduction did, contrary to E(2), not result in a decrease of the fluorescent response. Therefore, the superinduction was most likely the result of stabilization of the ER, yeast-enhanced green fluorescent protein, or a combination of both. Most fractions displaying superinduction were rich in flavonoids with single prenylation. Glabridin displayed ERα-selective antagonism, similar to the ERα-selective antagonist RU 58668. Whereas glabridin was able to reduce the estrogenic response of E(2) by approximately 80% at 6 × 10(-6) M, glabrene-rich fractions only exhibited agonistic responses, preferentially on ERα.
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Affiliation(s)
- Rudy Simons
- Laboratory of Food Chemistry, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
- Frutarom Netherlands BV, Landjuweel 5, 3905 PE Veenendaal, The Netherlands
| | - Jean-Paul Vincken
- Laboratory of Food Chemistry, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
| | - Loes A. M. Mol
- Laboratory of Food Chemistry, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
| | - Susan A. M. The
- Laboratory of Food Chemistry, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
| | - Toine F. H. Bovee
- Department of Safety and Health, RIKILT-Institute of Food Safety, P.O. Box 230, 6700 AE Wageningen, The Netherlands
| | | | | | - Harry Gruppen
- Laboratory of Food Chemistry, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
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Literature Search and Review. Assay Drug Dev Technol 2010. [DOI: 10.1089/adt.2010.0806.lr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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