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Eliesen GAM, Woutersen M, van Engelen J, Muller A. Does REACH provide sufficient information to regulate substances toxic to reproduction? Regul Toxicol Pharmacol 2023; 143:105462. [PMID: 37500049 DOI: 10.1016/j.yrtph.2023.105462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 07/20/2023] [Accepted: 07/24/2023] [Indexed: 07/29/2023]
Abstract
Hazard classification and risk assessment of substances, is essential to protect workers and consumers from hazardous substances including reproductive toxicants. The ability to classify substances for reproductive toxicity under the current REACH information requirements has been assessed. For low tonnage substances (<10 ton per annum (tpa)) information for classification is insufficient. When only a reproductive screening study is available (10-100 tpa), substances are mostly not classified in Category 1B as developmental and non-potent fertility effects may be missed. The information requirements could be improved by automatic triggering of follow-up studies in case of a Category 2 classification based on a screening study. Additionally, a study could be added to the information requirements for substances produced at 1-10 tpa. Performing a risk assessment is often problematic due to the limited study requirements at low tonnage levels. Only for substances produced at more than 100 tpa, there is a high likelihood to detect reproductive effects and perform accurate risk assessment provided that the extended-one-generation-reproductive-toxicity-study and/or extra cohorts are triggered where required. Regardless of the tonnage level, no specific studies on lactation are required. With this paper we intend to contribute to the discussion on the information requirements for reproductive toxicity in view of the REACH revision.
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Affiliation(s)
- Gaby A M Eliesen
- National Institute for Public Health and the Environment (RIVM), Centre for Safety of Substances and Products (VSP), Bilthoven, the Netherlands.
| | - M Woutersen
- National Institute for Public Health and the Environment (RIVM), Centre for Safety of Substances and Products (VSP), Bilthoven, the Netherlands
| | - J van Engelen
- National Institute for Public Health and the Environment (RIVM), Centre for Safety of Substances and Products (VSP), Bilthoven, the Netherlands
| | - A Muller
- National Institute for Public Health and the Environment (RIVM), Centre for Safety of Substances and Products (VSP), Bilthoven, the Netherlands
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2
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Luconi M, Sogorb MA, Markert UR, Benfenati E, May T, Wolbank S, Roncaglioni A, Schmidt A, Straccia M, Tait S. Human-Based New Approach Methodologies in Developmental Toxicity Testing: A Step Ahead from the State of the Art with a Feto-Placental Organ-on-Chip Platform. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:15828. [PMID: 36497907 PMCID: PMC9737555 DOI: 10.3390/ijerph192315828] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/20/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
Developmental toxicity testing urgently requires the implementation of human-relevant new approach methodologies (NAMs) that better recapitulate the peculiar nature of human physiology during pregnancy, especially the placenta and the maternal/fetal interface, which represent a key stage for human lifelong health. Fit-for-purpose NAMs for the placental-fetal interface are desirable to improve the biological knowledge of environmental exposure at the molecular level and to reduce the high cost, time and ethical impact of animal studies. This article reviews the state of the art on the available in vitro (placental, fetal and amniotic cell-based systems) and in silico NAMs of human relevance for developmental toxicity testing purposes; in addition, we considered available Adverse Outcome Pathways related to developmental toxicity. The OECD TG 414 for the identification and assessment of deleterious effects of prenatal exposure to chemicals on developing organisms will be discussed to delineate the regulatory context and to better debate what is missing and needed in the context of the Developmental Origins of Health and Disease hypothesis to significantly improve this sector. Starting from this analysis, the development of a novel human feto-placental organ-on-chip platform will be introduced as an innovative future alternative tool for developmental toxicity testing, considering possible implementation and validation strategies to overcome the limitation of the current animal studies and NAMs available in regulatory toxicology and in the biomedical field.
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Affiliation(s)
- Michaela Luconi
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
- I.N.B.B. (Istituto Nazionale Biostrutture e Biosistemi), Viale Medaglie d’Oro 305, 00136 Rome, Italy
| | - Miguel A. Sogorb
- Instituto de Bioingeniería, Universidad Miguel Hernández de Elche, Avenida de la Universidad s/n, 03202 Elche, Spain
| | - Udo R. Markert
- Placenta Lab, Department of Obstetrics, University Hospital Jena, Am Klinikum 1, 07747 Jena, Germany
| | - Emilio Benfenati
- Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milan, Italy
| | - Tobias May
- InSCREENeX GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany
| | - Susanne Wolbank
- Ludwig Boltzmann Institut for Traumatology, The Research Center in Cooperation with AUVA, Austrian Cluster for Tissue Regeneration, Donaueschingenstrasse 13, 1200 Vienna, Austria
| | - Alessandra Roncaglioni
- Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milan, Italy
| | - Astrid Schmidt
- Placenta Lab, Department of Obstetrics, University Hospital Jena, Am Klinikum 1, 07747 Jena, Germany
| | - Marco Straccia
- FRESCI by Science&Strategy SL, C/Roure Monjo 33, Vacarisses, 08233 Barcelona, Spain
| | - Sabrina Tait
- Centre for Gender-Specific Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy
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3
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Najjar A, Schepky A, Krueger CT, Dent M, Cable S, Li H, Grégoire S, Roussel L, Noel-Voisin A, Hewitt NJ, Cardamone E. Use of Physiologically-Based Kinetics Modelling to Reliably Predict Internal Concentrations of the UV Filter, Homosalate, After Repeated Oral and Topical Application. Front Pharmacol 2022; 12:802514. [PMID: 35058784 PMCID: PMC8763688 DOI: 10.3389/fphar.2021.802514] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 11/22/2021] [Indexed: 01/09/2023] Open
Abstract
Ethical and legal considerations have led to increased use of non-animal methods to evaluate the safety of chemicals for human use. We describe the development and qualification of a physiologically-based kinetics (PBK) model for the cosmetic UV filter ingredient, homosalate, to support its safety without the need of generating further animal data. The intravenous (IV) rat PBK model, using PK-Sim®, was developed and validated using legacy in vivo data generated prior to the 2013 EU animal-testing ban. Input data included literature or predicted physicochemical and pharmacokinetic properties. The refined IV rat PBK model was subject to sensitivity analysis to identify homosalate-specific sensitive parameters impacting the prediction of Cmax (more sensitive than AUC(0-∞)). These were then considered, together with population modeling, to calculate the confidence interval (CI) 95% Cmax and AUC(0-∞). Final model parameters were established by visual inspection of the simulations and biological plausibility. The IV rat model was extrapolated to oral administration, and used to estimate internal exposures to doses tested in an oral repeated dose toxicity study. Next, a human PBK dermal model was developed using measured human in vitro ADME data and a module to represent the dermal route. Model performance was confirmed by comparing predicted and measured values from a US-FDA clinical trial (Identifier: NCT03582215, https://clinicaltrials.gov/). Final exposure estimations were obtained in a virtual population and considering the in vitro and input parameter uncertainty. This model was then used to estimate the Cmax and AUC(0-24 h) of homosalate according to consumer use in a sunscreen. The developed rat and human PBK models had a good biological basis and reproduced in vivo legacy rat and human clinical kinetics data. They also complied with the most recent WHO and OECD recommendations for assessing the confidence level. In conclusion, we have developed a PBK model which predicted reasonably well the internal exposure of homosalate according to different exposure scenarios with a medium to high level of confidence. In the absence of in vivo data, such human PBK models will be the heart of future completely non-animal risk assessments; therefore, valid approaches will be key in gaining their regulatory acceptance. Clinical Trial Registration: https://clinicaltrials.gov/, identifier, NCT03582215.
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Affiliation(s)
| | | | | | - Matthew Dent
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, United Kingdom
| | - Sophie Cable
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, United Kingdom
| | - Hequn Li
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, United Kingdom
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4
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O'Shaughnessy KL, Gilbert ME. Thyroid disrupting chemicals and developmental neurotoxicity - New tools and approaches to evaluate hormone action. Mol Cell Endocrinol 2020; 518:110663. [PMID: 31760043 PMCID: PMC8270644 DOI: 10.1016/j.mce.2019.110663] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 11/20/2019] [Accepted: 11/20/2019] [Indexed: 12/25/2022]
Abstract
It is well documented that thyroid hormone (TH) action is critical for normal brain development and is mediated by both nuclear and extranuclear pathways. Given this dependence, the impact of environmental endocrine disrupting chemicals that interfere with thyroid signaling is a major concern with direct implications for children's health. However, identifying thyroid disrupting chemicals in vivo is primarily reliant on serum thyroxine (T4) measurements within greater developmental and reproductive toxicity assessments. These studies do not examine known TH-dependent phenotypes in parallel, which complicates chemical evaluation. Additionally, there exist no recommendations regarding what degree of serum T4 dysfunction is adverse, and little consideration is given to quantifying TH action within the developing brain. This review summarizes current testing strategies in rodent models and discusses new approaches for evaluating the developmental neurotoxicity of thyroid disrupting chemicals. This includes assays to identify adverse cellular effects of the brain by both immunohistochemistry and gene expression, which would compliment serum T4 measures. While additional experiments are needed to test the full utility of these approaches, incorporation of these cellular and molecular assays could enhance chemical evaluation in the regulatory arena.
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Affiliation(s)
- Katherine L O'Shaughnessy
- United States Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Toxicity Assessment Division, Endocrine Toxicology Branch, Research Triangle Park, NC, 27711, USA.
| | - Mary E Gilbert
- United States Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Toxicity Assessment Division, Endocrine Toxicology Branch, Research Triangle Park, NC, 27711, USA.
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5
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Bal-Price A, Pistollato F, Sachana M, Bopp SK, Munn S, Worth A. Strategies to improve the regulatory assessment of developmental neurotoxicity (DNT) using in vitro methods. Toxicol Appl Pharmacol 2018; 354:7-18. [PMID: 29476865 PMCID: PMC6095942 DOI: 10.1016/j.taap.2018.02.008] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 02/05/2018] [Accepted: 02/13/2018] [Indexed: 01/23/2023]
Abstract
Currently, the identification of chemicals that have the potential to induce developmental neurotoxicity (DNT) is based on animal testing. Since at the regulatory level, systematic testing of DNT is not a standard requirement within the EU or USA chemical legislation safety assessment, DNT testing is only performed in higher tiered testing triggered based on chemical structure activity relationships or evidence of neurotoxicity in systemic acute or repeated dose toxicity studies. However, these triggers are rarely used and, in addition, do not always serve as reliable indicators of DNT, as they are generally based on observations in adult rodents. Therefore, there is a pressing need for developing alternative methodologies that can reliably support identification of DNT triggers, and more rapidly and cost-effectively support the identification and characterization of chemicals with DNT potential. We propose to incorporate mechanistic knowledge and data derived from in vitro studies to support various regulatory applications including: (a) the identification of potential DNT triggers, (b) initial chemical screening and prioritization, (c) hazard identification and characterization, (d) chemical biological grouping, and (e) assessment of exposure to chemical mixtures. Ideally, currently available cellular neuronal/glial models derived from human induced pluripotent stem cells (hiPSCs) should be used as they allow evaluation of chemical impacts on key neurodevelopmental processes, by reproducing different windows of exposure during human brain development. A battery of DNT in vitro test methods derived from hiPSCs could generate valuable mechanistic data, speeding up the evaluation of thousands of compounds present in industrial, agricultural and consumer products that lack safety data on DNT potential.
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Affiliation(s)
- Anna Bal-Price
- European Commission, Joint Research Centre (JRC), Ispra, Italy.
| | | | - Magdalini Sachana
- Organisation for Economic Co-operation and Development (OECD), 2 rue André Pascal, 75775 Paris, Cedex 16, France
| | | | - Sharon Munn
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Andrew Worth
- European Commission, Joint Research Centre (JRC), Ispra, Italy
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6
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Aydιn A, Aktay G, Yesilada E. A Guidance Manual for the Toxicity Assessment of Traditional Herbal Medicines. Nat Prod Commun 2016. [DOI: 10.1177/1934578x1601101131] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Herbal remedies have been used for thousands of years in worldwide traditional medicines for their potential health benefits. Although they are generally presumed safe unless a significant risk has been identified in humans, increasing number of case reports notify acute or chronic intoxications resulting from their use. This study aims to produce a scientific guide for the evaluation of traditional herbal medicines (THMs) in terms of their toxicity risks based on the published regulatory documents. For this purpose recommended in vitro and in vivo toxicity tests on medicinal products for human use issued by the international regulatory bodies are overviewed and they are then adopted to be used for the toxicity assessment of THMs. Accordingly, based on compilation of these issued regulations, the following tests are recommended for the toxicity assessment of THMs; in vitro cytotoxicity, genotoxicity, acute and repeated dose toxicity, carcinogenicity, reproductive and developmental toxicity, local tolerance tests, toxicokinetic studies, and additional toxicity tests including safety pharmacology, immunotoxicity and antigenicity, endocrine system toxicity, gastro-intestinal toxicity, renal and hepatotoxicity, and drug interaction studies. This study describes and discusses the applicability of these tests for the risk assessment in THMs.
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Affiliation(s)
- Ahmet Aydιn
- Yeditepe University, Faculty of Pharmacy, Dept. Toxicology, Atasehir, 34755 Istanbul, Turkey
| | - Göknur Aktay
- Inönü University, Faculty of Pharmacy, Dept. Pharmacology, Malatya, Turkey
| | - Erdem Yesilada
- Yeditepe University, Faculty of Pharmacy, Dept. Pharmacognosy, Atasehir, 34755 Istanbul, Turkey
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7
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Kugler J, Luch A, Oelgeschläger M. Transgenic Mouse Models Transferred into the Test Tube: New Perspectives for Developmental Toxicity Testing In Vitro? Trends Pharmacol Sci 2016; 37:822-830. [PMID: 27450043 DOI: 10.1016/j.tips.2016.06.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 06/24/2016] [Accepted: 06/30/2016] [Indexed: 11/17/2022]
Abstract
Despite our increasing understanding of molecular mechanisms controlling embryogenesis, the identification and characterization of teratogenic substances still heavily relies on animal testing. Embryonic development depends on cell-autonomous and non-autonomous processes including spatiotemporally regulated extracellular signaling activities. These have been elucidated in transgenic mouse models harboring easily detectable reporter genes under the control of evolutionarily conserved signaling cascades. We propose combining these transgenic mouse models and cells derived thereof with existing alternative toxicological testing strategies. This would enable the plausibility of in vitro data to be verified in light of in vivo data and, ultimately, facilitate regulatory acceptance of in vitro test methods.
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Affiliation(s)
- Josephine Kugler
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Andreas Luch
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany.
| | - Michael Oelgeschläger
- German Federal Institute for Risk Assessment (BfR), Department of Experimental Toxicology and ZEBET, Bf3R, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
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8
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Ema M, Hougaard KS, Kishimoto A, Honda K. Reproductive and developmental toxicity of carbon-based nanomaterials: A literature review. Nanotoxicology 2015; 10:391-412. [DOI: 10.3109/17435390.2015.1073811] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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9
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The underestimated value of OECD 421 and 422 repro screening studies: Putting it in the right perspective. Reprod Toxicol 2014; 48:81-7. [DOI: 10.1016/j.reprotox.2014.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 04/01/2014] [Accepted: 04/14/2014] [Indexed: 11/20/2022]
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10
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Tanago A, Ikeuchi T. Stable reporter gene assay based on Gal4-vitamin D receptor β fusion proteins in medaka (Oryzias latipes), and its transactivational properties. Zoolog Sci 2014; 31:195-201. [PMID: 24694221 DOI: 10.2108/zs130217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The transactivational property of natural and synthetic chemicals via medaka vitamin D receptor β subtype (VDRβ) was investigated after the development of a stable cell line expressing a Gal4-VDRβ fusion protein for reporter gene assay. Members of vitamin D class, including 1α, 25- dihydroxyvitamin D3 (1,25VD3) were specifically detected as agonists in our system. Although other steroids and chemicals used in the present estimation induced no agonistic response, 10 compounds displayed antagonistic or synergistic activity. Spironolactone, which is an antagonist of corticoid receptors in mammals, competitively inhibited the transactivity of 1,25VD3 by over 80% in a dose dependent manner. Mifepristone and cyproterone acetate were also detected as antagonists, but they significantly acted only at 10µ. Pregnenolone and raloxifene dose-dependently enhanced the activity of 1,25VD3 at EC50 to the maximum level. Diethylstilbestrol, 17α-ethynylestradiol, genistein, and stanozolol were also synergists, but their potency was low. Interestingly, dibutyltin dichloride, which is used as a stabilizer in the production of polyvinyl chloride plastics, produced greater response than maximum effect of 1,25VD3 although the concentration-response curve was not typically sigmoidal. In the present study, we successfully developed a stable reporter gene assay, which allows assessment of the vitamin D-like chemicals toward the medaka VDRβ.
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Affiliation(s)
- Atsushi Tanago
- Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga 526-0829, Japan
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11
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Aulmann W. Assessment of reproductive toxicity under REACH. Regul Toxicol Pharmacol 2012; 63:286-90. [PMID: 22475931 DOI: 10.1016/j.yrtph.2012.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 02/29/2012] [Accepted: 03/06/2012] [Indexed: 10/28/2022]
Abstract
The European REACH regulation requires the evaluation of reproductive toxicity in screening tests according to OECD TG 421 and 422 for substances above the tonnage level of 10 tons/year. The overall aim of this paper is to increase flexibility in combination with a reduced number of experimental animals. Therefore, in contrast to the existing approach the registrant should have the possibility to file a dossier for a substance at the level of 10 tons/year and above also on the basis of data from a developmental toxicity study (OECD TG 414) plus a full-scale subacute toxicity study (OECD TG 407 according to the 1995 protocol). The proposed new test strategy takes into account overall considerations of duty of care and animal welfare. It enables an assessment of developmental toxicity on a definitive instead of a screening level. Registrants should be allowed to select between these two options, either the existing approach (OECD TG 421/407 and alternatively TG 422) or the approach proposed in this paper (OECD TG 407 plus TG 414).
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Affiliation(s)
- Walter Aulmann
- Ecolab Deutschland GmbH, Reisholzer Werftstr. 38-42, 40554 Düsseldorf, Germany.
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12
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Vogel R, Seidle T, Spielmann H. A modular one-generation reproduction study as a flexible testing system for regulatory safety assessment. Reprod Toxicol 2010; 29:242-5. [DOI: 10.1016/j.reprotox.2009.09.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Revised: 09/01/2009] [Accepted: 09/26/2009] [Indexed: 11/27/2022]
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13
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Dekant W, Melching-Kollmuß S, Kalberlah F. Toxicity assessment strategies, data requirements, and risk assessment approaches to derive health based guidance values for non-relevant metabolites of plant protection products. Regul Toxicol Pharmacol 2010; 56:135-42. [DOI: 10.1016/j.yrtph.2009.10.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 09/28/2009] [Accepted: 10/22/2009] [Indexed: 10/20/2022]
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14
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Chung MK, Baek SS, Lee SH, Kim H, Choi K, Kim JC. Combined repeated dose and reproductive/developmental toxicities of copper monochloride in rats. ENVIRONMENTAL TOXICOLOGY 2009; 24:315-326. [PMID: 18767139 DOI: 10.1002/tox.20433] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
This study investigated the combined repeated dose and reproductive/developmental toxicity of copper monochloride in rats. The test substance was administered once daily by gavage at 0, 1.3, 5, 20, or 80 mg/kg/day. Male rats were dosed for a total of 30 days beginning 14 days before mating. Female rats were dosed from 2 weeks before mating to day 3 of lactation throughout the mating and gestation period. At 80 mg/kg/day, deaths were observed in 3 out of 12 females. There was a dose-dependent increase in the incidence of clinical signs and a reduction in the food consumption. Hematological and serum biochemical investigations revealed a decrease in the red blood cell, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin (MCH), and serum total protein levels and an increase in the white blood cell and platelets in males, and a decrease in the MCH and an increase in the platelets in females. Histopathological examination showed an increased incidence of squamous cell hyperplasia of the stomach in both genders as well as increased hematopoiesis of the femur in males. There was an increase in the number of icteric and runt pups at birth. At 20 mg/kg/day, there was an increase in the incidence of clinical signs and squamous cell hyperplasia of the stomach in both genders. At 5 mg/kg/day, an increase in the incidence of squamous cell hyperplasia of the stomach was observed in females. There were no adverse effects in the lowest group in both genders. Based on these findings, the no-observed-adverse-effect levels of copper monochloride were concluded to be 5 mg/kg/day in male rats and 1.3 mg/kg/day in female rats for general toxicity and 20 mg/kg/day for reproductive/developmental toxicity.
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Affiliation(s)
- Moon-Koo Chung
- Korea Institute of Toxicology, KRICT, Daejeon, Republic of Korea
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15
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Existing approaches incorporating replacement, reduction and refinement of animal testing: applicability in food and feed risk assessment. EFSA J 2009. [DOI: 10.2903/j.efsa.2009.1052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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16
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Cao B, Ren Q, Cui Z, Li P, Cao J. Evaluation of reproductive toxicity in rats caused by organic extracts of Jialing River water of Chongqing, China. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2009; 27:357-365. [PMID: 21783965 DOI: 10.1016/j.etap.2008.12.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 11/27/2008] [Accepted: 12/03/2008] [Indexed: 05/31/2023]
Abstract
OECD 421 screening test protocol was used to evaluate the reproductive toxicity of organic extracts of river water. These extracts, at doses of 0, 2, 16, or 80 equivalent L/kgbody weight(bw), were administered to rats daily by oral gavage. Vacuole degeneration of seminiferous epithelium was observed in the dosed groups. The caudal sperm counts/epididymis weight and the percentages of sperm with abnormal heads were increased in the group dosed with 80L/kgbw/day compared to the control group. Exposure of rats to organic extracts at the high dose resulted in a decrease in testosterone levels. The serum level of follicle-stimulating hormone increased in the groups dosed with 16 or 80L/kgbw/day compared to the control group. The number of apoptotic spermatid increased in the dosed groups. The results suggest that the extracts cause pathological damage to testicular tissue and disruption of spermatogenesis.
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Affiliation(s)
- Bo Cao
- Department of Pharmacognosy, School of Pharmacy, Third Military Medical University, Chongqing 400038, People's Republic of China
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17
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Cooper RL, Lamb JC, Barlow SM, Bentley K, Brady AM, Doerrer NG, Eisenbrandt DL, Fenner-Crisp PA, Hines RN, Irvine LFH, Kimmel CA, Koeter H, Li AA, Makris SL, Sheets LP, Speijers G, Whitby KE. A Tiered Approach to Life Stages Testing for Agricultural Chemical Safety Assessment. Crit Rev Toxicol 2008; 36:69-98. [PMID: 16708695 DOI: 10.1080/10408440500541367] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
A proposal has been developed by the Agricultural Chemical Safety Assessment (ACSA) Technical Committee of the ILSI Health and Environmental Sciences Institute (HESI) for an improved approach to assessing the safety of crop protection chemicals. The goal is to ensure that studies are scientifically appropriate and necessary without being redundant, and that tests emphasize toxicological endpoints and exposure durations that are relevant for risk assessment. The ACSA Life Stages Task Force proposes a tiered approach to toxicity testing that assesses a compound's potential to cause adverse effects on reproduction, and that assesses the nature and severity of effects during development and adolescence, with consideration of the sensitivity of the elderly. While incorporating many features from current guideline studies, the proposed approach includes a novel rat reproduction and developmental study with enhanced endpoints and a rabbit development study. All available data, including toxicokinetics, ADME data, and systemic toxicity information, are considered in the design and interpretation of studies. Compared to existing testing strategies, the proposed approach uses fewer animals, provides information on the young animal, and includes an estimation of human exposure potential for making decisions about the extent of testing required.
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Affiliation(s)
- Ralph L Cooper
- U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Research Triangle Park, North Carolina, USA
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18
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Background, approaches and recent trends for setting health-based occupational exposure limits: a minireview. Regul Toxicol Pharmacol 2008; 51:253-69. [PMID: 18502550 DOI: 10.1016/j.yrtph.2008.04.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Revised: 03/24/2008] [Accepted: 04/07/2008] [Indexed: 12/29/2022]
Abstract
The setting of occupational exposure limits (OELs) are founded in occupational medicine and the predictive toxicological testing, resulting in exposure-response relationships. For compounds where a No-Observed-Adverse-Effect-Level (NOAEL) can be established, health-based OELs are set by dividing the NOAEL of the critical effect by an overall uncertainty factor. Possibly, the approach may also be used for carcinogens if the mechanism is epigenetic or the genetic effect is secondary to effect from reactions with proteins such as topoisomerase inhibitors, and mitotic and meiotic spindle poisons. Additionally, the NOAEL approach may also be used for compounds with weak genotoxic effect, playing no or only a minor role in the development of tumours. No health-based OEL can be set for direct-acting genotoxic compounds where the life-time risks may be estimated from the low-dose linear non-threshold extrapolation, allowing a politically based exposure level to be set. OELs are set by several agencies in the US and Europe, but also in-house in major chemical and pharmaceutical companies. The benchmark dose approach may in the future be used where it has advantage over the NOAEL approach. Also, more attention should be devoted to sensitive groups, toxicological mechanisms and interactions as most workplace exposures are mixtures.
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Gelbke HP, Fleig H, Meder M. SIDS reprotoxicity screening test update: testing strategies and use. Regul Toxicol Pharmacol 2004; 39:81-6. [PMID: 15041141 DOI: 10.1016/j.yrtph.2003.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2003] [Indexed: 11/17/2022]
Abstract
The OECD screening information data set (SIDS) project is a cooperative effort of OECD member countries and industry to assess the hazard/risk posed to human health and the environment by high production volume (HPV) chemicals, and to assign priorities for further work. To date, work has been initiated on about 1000 HPV chemicals. Abbreviated reproduction and developmental toxicity screening tests (OECD test guidelines 421 and 422) were developed specifically for the SIDS project. These tests, though not providing a complete characterization of reproductive or developmental hazard, are accepted in USA and Japan as fulfilling the requirement of an initial reproduction and developmental toxicity evaluation for HPV chemicals. Based on the OECD-approved SIDS initial assessments for 54 substances tested according to guideline 421 or 422, these tests are providing useful data for initial hazard assessment.
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