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Silva AC, Loizou GD, McNally K, Osborne O, Potter C, Gott D, Colbourne JK, Viant MR. A novel method to derive a human safety limit for PFOA by gene expression profiling and modelling. FRONTIERS IN TOXICOLOGY 2024; 6:1368320. [PMID: 38577564 PMCID: PMC10991825 DOI: 10.3389/ftox.2024.1368320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 03/01/2024] [Indexed: 04/06/2024] Open
Abstract
Perfluorooctanoic acid (PFOA) is a persistent environmental contaminant that can accumulate in the human body due to its long half-life. This substance has been associated with liver, pancreatic, testicular and breast cancers, liver steatosis and endocrine disruption. PFOA is a member of a large group of substances also known as "forever chemicals" and the vast majority of substances of this group lack toxicological data that would enable their effective risk assessment in terms of human health hazards. This study aimed to derive a health-based guidance value for PFOA intake (ng/kg BW/day) from in vitro transcriptomics data. To this end, we developed an in silico workflow comprising five components: (i) sourcing in vitro hepatic transcriptomics concentration-response data; (ii) deriving molecular points of departure using BMDExpress3 and performing pathway analysis using gene set enrichment analysis (GSEA) to identify the most sensitive molecular pathways to PFOA exposure; (iii) estimating freely-dissolved PFOA concentrations in vitro using a mass balance model; (iv) estimating in vivo doses by reverse dosimetry using a PBK model for PFOA as part of a quantitative in vitro to in vivo extrapolation (QIVIVE) algorithm; and (v) calculating a tolerable daily intake (TDI) for PFOA. Fourteen percent of interrogated genes exhibited in vitro concentration-response relationships. GSEA pathway enrichment analysis revealed that "fatty acid metabolism" was the most sensitive pathway to PFOA exposure. In vitro free PFOA concentrations were calculated to be 2.9% of the nominal applied concentrations, and these free concentrations were input into the QIVIVE workflow. Exposure doses for a virtual population of 3,000 individuals were estimated, from which a TDI of 0.15 ng/kg BW/day for PFOA was calculated using the benchmark dose modelling software, PROAST. This TDI is comparable to previously published values of 1.16, 0.69, and 0.86 ng/kg BW/day by the European Food Safety Authority. In conclusion, this study demonstrates the combined utility of an "omics"-derived molecular point of departure and in silico QIVIVE workflow for setting health-based guidance values in anticipation of the acceptance of in vitro concentration-response molecular measurements in chemical risk assessment.
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Affiliation(s)
- Arthur de Carvalho e Silva
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- Centre for Environmental Research and Justice (CERJ), University of Birmingham, Birmingham, United Kingdom
| | | | | | - Olivia Osborne
- Science Evidence and Research Division, Food Standards Agency, London, United Kingdom
| | - Claire Potter
- Science Evidence and Research Division, Food Standards Agency, London, United Kingdom
| | - David Gott
- Science Evidence and Research Division, Food Standards Agency, London, United Kingdom
| | - John K. Colbourne
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- Centre for Environmental Research and Justice (CERJ), University of Birmingham, Birmingham, United Kingdom
| | - Mark R. Viant
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- Centre for Environmental Research and Justice (CERJ), University of Birmingham, Birmingham, United Kingdom
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2
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Chang X, Tan YM, Allen DG, Bell S, Brown PC, Browning L, Ceger P, Gearhart J, Hakkinen PJ, Kabadi SV, Kleinstreuer NC, Lumen A, Matheson J, Paini A, Pangburn HA, Petersen EJ, Reinke EN, Ribeiro AJS, Sipes N, Sweeney LM, Wambaugh JF, Wange R, Wetmore BA, Mumtaz M. IVIVE: Facilitating the Use of In Vitro Toxicity Data in Risk Assessment and Decision Making. TOXICS 2022; 10:232. [PMID: 35622645 PMCID: PMC9143724 DOI: 10.3390/toxics10050232] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 04/24/2022] [Indexed: 02/04/2023]
Abstract
During the past few decades, the science of toxicology has been undergoing a transformation from observational to predictive science. New approach methodologies (NAMs), including in vitro assays, in silico models, read-across, and in vitro to in vivo extrapolation (IVIVE), are being developed to reduce, refine, or replace whole animal testing, encouraging the judicious use of time and resources. Some of these methods have advanced past the exploratory research stage and are beginning to gain acceptance for the risk assessment of chemicals. A review of the recent literature reveals a burst of IVIVE publications over the past decade. In this review, we propose operational definitions for IVIVE, present literature examples for several common toxicity endpoints, and highlight their implications in decision-making processes across various federal agencies, as well as international organizations, including those in the European Union (EU). The current challenges and future needs are also summarized for IVIVE. In addition to refining and reducing the number of animals in traditional toxicity testing protocols and being used for prioritizing chemical testing, the goal to use IVIVE to facilitate the replacement of animal models can be achieved through their continued evolution and development, including a strategic plan to qualify IVIVE methods for regulatory acceptance.
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Affiliation(s)
- Xiaoqing Chang
- Inotiv-RTP, 601 Keystone Park Drive, Suite 200, Morrisville, NC 27560, USA; (X.C.); (D.G.A.); (S.B.); (L.B.); (P.C.)
| | - Yu-Mei Tan
- U.S. Environmental Protection Agency, Office of Pesticide Programs, 109 T.W. Alexander Drive, Durham, NC 27709, USA;
| | - David G. Allen
- Inotiv-RTP, 601 Keystone Park Drive, Suite 200, Morrisville, NC 27560, USA; (X.C.); (D.G.A.); (S.B.); (L.B.); (P.C.)
| | - Shannon Bell
- Inotiv-RTP, 601 Keystone Park Drive, Suite 200, Morrisville, NC 27560, USA; (X.C.); (D.G.A.); (S.B.); (L.B.); (P.C.)
| | - Paul C. Brown
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, 10903 New Hampshire Avenue, Silver Spring, MD 20903, USA; (P.C.B.); (A.J.S.R.); (R.W.)
| | - Lauren Browning
- Inotiv-RTP, 601 Keystone Park Drive, Suite 200, Morrisville, NC 27560, USA; (X.C.); (D.G.A.); (S.B.); (L.B.); (P.C.)
| | - Patricia Ceger
- Inotiv-RTP, 601 Keystone Park Drive, Suite 200, Morrisville, NC 27560, USA; (X.C.); (D.G.A.); (S.B.); (L.B.); (P.C.)
| | - Jeffery Gearhart
- The Henry M. Jackson Foundation, Air Force Research Laboratory, 711 Human Performance Wing, Wright-Patterson Air Force Base, OH 45433, USA;
| | - Pertti J. Hakkinen
- National Library of Medicine, National Center for Biotechnology Information, 8600 Rockville Pike, Bethesda, MD 20894, USA;
| | - Shruti V. Kabadi
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Food Additive Safety, 5001 Campus Drive, HFS-275, College Park, MD 20740, USA;
| | - Nicole C. Kleinstreuer
- National Institute of Environmental Health Sciences, National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods, P.O. Box 12233, Research Triangle Park, NC 27709, USA;
| | - Annie Lumen
- U.S. Food and Drug Administration, National Center for Toxicological Research, 3900 NCTR Road, Jefferson, AR 72079, USA;
| | - Joanna Matheson
- U.S. Consumer Product Safety Commission, Division of Toxicology and Risk Assessment, 5 Research Place, Rockville, MD 20850, USA;
| | - Alicia Paini
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy;
| | - Heather A. Pangburn
- Air Force Research Laboratory, 711 Human Performance Wing, 2729 R Street, Area B, Building 837, Wright-Patterson Air Force Base, OH 45433, USA;
| | - Elijah J. Petersen
- U.S. Department of Commerce, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA;
| | - Emily N. Reinke
- U.S. Army Public Health Center, 8252 Blackhawk Rd., Aberdeen Proving Ground, MD 21010, USA;
| | - Alexandre J. S. Ribeiro
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, 10903 New Hampshire Avenue, Silver Spring, MD 20903, USA; (P.C.B.); (A.J.S.R.); (R.W.)
| | - Nisha Sipes
- U.S. Environmental Protection Agency, Center for Computational Toxicology and Exposure, 109 TW Alexander Dr., Research Triangle Park, NC 27711, USA; (N.S.); (J.F.W.); (B.A.W.)
| | - Lisa M. Sweeney
- UES, Inc., 4401 Dayton-Xenia Road, Beavercreek, OH 45432, Assigned to Air Force Research Laboratory, 711 Human Performance Wing, Wright-Patterson Air Force Base, OH 45433, USA;
| | - John F. Wambaugh
- U.S. Environmental Protection Agency, Center for Computational Toxicology and Exposure, 109 TW Alexander Dr., Research Triangle Park, NC 27711, USA; (N.S.); (J.F.W.); (B.A.W.)
| | - Ronald Wange
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, 10903 New Hampshire Avenue, Silver Spring, MD 20903, USA; (P.C.B.); (A.J.S.R.); (R.W.)
| | - Barbara A. Wetmore
- U.S. Environmental Protection Agency, Center for Computational Toxicology and Exposure, 109 TW Alexander Dr., Research Triangle Park, NC 27711, USA; (N.S.); (J.F.W.); (B.A.W.)
| | - Moiz Mumtaz
- Agency for Toxic Substances and Disease Registry, Office of the Associate Director for Science, 1600 Clifton Road, S102-2, Atlanta, GA 30333, USA
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Loizou G, McNally K, Paini A, Hogg A. Derivation of a Human In Vivo Benchmark Dose for Bisphenol A from ToxCast In Vitro Concentration Response Data Using a Computational Workflow for Probabilistic Quantitative In Vitro to In Vivo Extrapolation. Front Pharmacol 2022; 12:754408. [PMID: 35222005 PMCID: PMC8874249 DOI: 10.3389/fphar.2021.754408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 11/15/2021] [Indexed: 11/23/2022] Open
Abstract
A computational workflow which integrates physiologically based kinetic (PBK) modelling; global sensitivity analysis (GSA), Approximate Bayesian Computation (ABC), Markov Chain Monte Carlo (MCMC) simulation and the Virtual Cell Based Assay (VCBA) for the estimation of the active, free in vitro concentration of chemical in the reaction medium was developed to facilitate quantitative in vitro to in vivo extrapolation (QIVIVE). The workflow was designed to estimate parameter and model uncertainty within a computationally efficient framework. The workflow was tested using a human PBK model for bisphenol A (BPA) and high throughput screening (HTS) in vitro concentration-response data, for estrogen and pregnane X receptor activation determined in human liver and kidney cell lines, from the ToxCast/Tox21 database. In vivo benchmark dose 10% lower confidence limits (BMDL10) for oral uptake of BPA (ng/kg BW/day) were calculated from the in vivo dose-responses and compared to the human equivalent dose (HED) BMDL10 for relative kidney weight change in the mouse derived by European Food Safety Authority (EFSA). Three from four in vivo BMDL10 values calculated in this study were similar to the EFSA values whereas the fourth was much smaller. The derivation of an uncertainty factor (UF) to accommodate the uncertainties associated with measurements using human cell lines in vitro, extrapolated to in vivo, could be useful for the derivation of Health Based Guidance Values (HBGV).
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Affiliation(s)
- George Loizou
- Health and Safety Executive, Harpur Hill, Buxton, United Kingdom
- *Correspondence: George Loizou,
| | - Kevin McNally
- Health and Safety Executive, Harpur Hill, Buxton, United Kingdom
| | - Alicia Paini
- European Commission Joint Research Centre, Ispra, Italy
| | - Alex Hogg
- Health and Safety Executive, Harpur Hill, Buxton, United Kingdom
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Widjaja F, Alhejji Y, Rietjens IMCM. The Role of Kinetics as Key Determinant in Toxicity of Pyrrolizidine Alkaloids and Their N-Oxides. PLANTA MEDICA 2022; 88:130-143. [PMID: 34741297 PMCID: PMC8807025 DOI: 10.1055/a-1582-9794] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Pyrrolizidine alkaloids (PAs) are a large group of plant constituents of which especially the 1,2- unsaturated PAs raise a concern because of their liver toxicity and potential genotoxic carcinogenicity. This toxicity of PAs depends on their kinetics. Differences in absorption, distribution, metabolism, and excretion (ADME) characteristics of PAs may substantially alter the relative toxicity of PAs. As a result, kinetics will also affect relative potency (REP) values. The present review summarizes the current state-of-the art on PA kinetics and resulting consequences for toxicity and illustrates how physiologically-based kinetic (PBK) modelling can be applied to take kinetics into account when defining the relative differences in toxicity between PAs in the in vivo situation. We conclude that toxicokinetics play an important role in the overall toxicity of pyrrolizidine alkaloids. and that kinetics should therefore be considered when defining REP values for combined risk assessment. New approach methodologies (NAMs) can be of use to quantify these kinetic differences between PAs and their N-oxides, thus contributing to the 3Rs (Replacement, Reduction and Refinement) in animal studies.
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Affiliation(s)
- Frances Widjaja
- Division of Toxicology, Wageningen University and Research, The Netherlands
| | - Yasser Alhejji
- Division of Toxicology, Wageningen University and Research, The Netherlands
- Department of Food Science and Human Nutrition, College of Agriculture and Veterinary Medicine, Qassim University, Buraydah, Saudi Arabia
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Loizou G, McNally K, Dorne JLCM, Hogg A. Derivation of a Human In Vivo Benchmark Dose for Perfluorooctanoic Acid From ToxCast In Vitro Concentration-Response Data Using a Computational Workflow for Probabilistic Quantitative In Vitro to In Vivo Extrapolation. Front Pharmacol 2021; 12:630457. [PMID: 34045957 PMCID: PMC8144460 DOI: 10.3389/fphar.2021.630457] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 03/01/2021] [Indexed: 01/11/2023] Open
Abstract
A computational workflow which integrates physiologically based kinetic (PBK) modeling, global sensitivity analysis (GSA), approximate Bayesian computation (ABC), and Markov Chain Monte Carlo (MCMC) simulation was developed to facilitate quantitative in vitro to in vivo extrapolation (QIVIVE). The workflow accounts for parameter and model uncertainty within a computationally efficient framework. The workflow was tested using a human PBK model for perfluorooctanoic acid (PFOA) and high throughput screening (HTS) in vitro concentration–response data, determined in a human liver cell line, from the ToxCast/Tox21 database. In vivo benchmark doses (BMDs) for PFOA intake (ng/kg BW/day) and drinking water exposure concentrations (µg/L) were calculated from the in vivo dose responses and compared to intake values derived by the European Food Safety Authority (EFSA). The intake benchmark dose lower confidence limit (BMDL5) of 0.82 was similar to 0.86 ng/kg BW/day for altered serum cholesterol levels derived by EFSA, whereas the intake BMDL5 of 6.88 was six-fold higher than the value of 1.14 ng/kg BW/day for altered antibody titer also derived by the EFSA. Application of a chemical-specific adjustment factor (CSAF) of 1.4, allowing for inter-individual variability in kinetics, based on biological half-life, gave an intake BMDL5 of 0.59 for serum cholesterol and 4.91 (ng/kg BW/day), for decreased antibody titer, which were 0.69 and 4.31 the EFSA-derived values, respectively. The corresponding BMDL5 for drinking water concentrations, for estrogen receptor binding activation associated with breast cancer, pregnane X receptor binding associated with altered serum cholesterol levels, thyroid hormone receptor α binding leading to thyroid disease, and decreased antibody titer (pro-inflammation from cytokines) were 0.883, 0.139, 0.086, and 0.295 ng/ml, respectively, with application of no uncertainty factors. These concentrations are 5.7-, 36-, 58.5-, and 16.9-fold lower than the median measured drinking water level for the general US population which is approximately, 5 ng/ml.
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Affiliation(s)
- George Loizou
- Health and Safety Executive, Harpur Hill, Buxton, United Kingdom
| | - Kevin McNally
- Health and Safety Executive, Harpur Hill, Buxton, United Kingdom
| | - Jean-Lou C M Dorne
- Scientific Committee and Emerging Risks Unit, European Food Safety Authority, Parma, Italy
| | - Alex Hogg
- Health and Safety Executive, Harpur Hill, Buxton, United Kingdom
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6
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Suparmi S, de Haan L, Spenkelink A, Louisse J, Beekmann K, Rietjens IMCM. Combining In Vitro Data and Physiologically Based Kinetic Modeling Facilitates Reverse Dosimetry to Define In Vivo Dose-Response Curves for Bixin- and Crocetin-Induced Activation of PPARγ in Humans. Mol Nutr Food Res 2020; 64:e1900880. [PMID: 31846197 PMCID: PMC7003908 DOI: 10.1002/mnfr.201900880] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/21/2019] [Indexed: 11/09/2022]
Abstract
SCOPE It is investigated whether at realistic dietary intake bixin and crocetin could induce peroxisome proliferator-activated receptor γ (PPARγ)-mediated gene expression in humans using a combined in vitro-in silico approach. METHODS AND RESULTS Concentration-response curves obtained from in vitro PPARγ-reporter gene assays are converted to in vivo dose-response curves using physiologically based kinetic modeling-facilitated reverse dosimetry, from which the benchmark dose levels resulting in a 50% effect above background level (BMD50 ) are predicted and subsequently compared to dietary exposure levels. Bixin and crocetin activated PPARγ-mediated gene transcription in a concentration-dependent manner with similar potencies. Due to differences in kinetics, the predicted BMD50 values for in vivo PPARγ activation are about 30-fold different, amounting to 115 and 3505 mg kg bw-1 for crocetin and bixin, respectively. Human dietary and/or supplemental estimated daily intakes may reach these BMD50 values for crocetin but not for bixin, pointing at better possibilities for in vivo PPARγ activation by crocetin. CONCLUSION Based on a combined in vitro-in silico approach, it is estimated whether at realistic dietary intakes plasma concentrations of bixin and crocetin are likely to reach concentrations that activate PPARγ-mediated gene expression, without the need for a human intervention study.
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Affiliation(s)
- Suparmi Suparmi
- Division of ToxicologyWageningen University and ResearchStippeneng 4, 6708 WE WageningenThe Netherlands
- Department of Biology, Faculty of MedicineUniversitas Islam Sultan AgungJl. Raya Kaligawe KM 450112SemarangIndonesia
| | - Laura de Haan
- Division of ToxicologyWageningen University and ResearchStippeneng 4, 6708 WE WageningenThe Netherlands
| | - Albertus Spenkelink
- Division of ToxicologyWageningen University and ResearchStippeneng 4, 6708 WE WageningenThe Netherlands
| | - Jochem Louisse
- Division of ToxicologyWageningen University and ResearchStippeneng 4, 6708 WE WageningenThe Netherlands
- Present address:
Wageningen Food Safety ResearchAkkermaalsbos 26708 WBWageningenThe Netherlands
| | - Karsten Beekmann
- Division of ToxicologyWageningen University and ResearchStippeneng 4, 6708 WE WageningenThe Netherlands
- Present address:
Wageningen Food Safety ResearchAkkermaalsbos 26708 WBWageningenThe Netherlands
| | - Ivonne M. C. M. Rietjens
- Division of ToxicologyWageningen University and ResearchStippeneng 4, 6708 WE WageningenThe Netherlands
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7
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Ning J, Chen L, Rietjens IM. Role of toxicokinetics and alternative testing strategies in pyrrolizidine alkaloid toxicity and risk assessment; state-of-the-art and future perspectives. Food Chem Toxicol 2019; 131:110572. [DOI: 10.1016/j.fct.2019.110572] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 06/05/2019] [Accepted: 06/07/2019] [Indexed: 01/31/2023]
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Scanarotti C, Vernazza S, Brignone M, Danailova J, Pronzato MA, Bassi AM. Evaluation of the Cytotoxic Effects of Humid Lightweight Coal Ash derived from the Disposal of Waste on Normal Human Keratinocyte and Endothelial Cell Lines in 2-D and 3-D Culture. Altern Lab Anim 2019; 41:491-502. [DOI: 10.1177/026119291304100612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Chiara Scanarotti
- Department of Experimental Medicine, Section of General Pathology, Laboratory of Analysis and Research in Physiopathology (LARF), University of Genoa, Italy
| | - Stefania Vernazza
- Department of Experimental Medicine, Section of General Pathology, Laboratory of Analysis and Research in Physiopathology (LARF), University of Genoa, Italy
| | | | - Jenia Danailova
- Department of Experimental Medicine, Section of General Pathology, Laboratory of Analysis and Research in Physiopathology (LARF), University of Genoa, Italy
| | - Maria A. Pronzato
- Department of Experimental Medicine, Section of General Pathology, Laboratory of Analysis and Research in Physiopathology (LARF), University of Genoa, Italy
| | - Anna M. Bassi
- Department of Experimental Medicine, Section of General Pathology, Laboratory of Analysis and Research in Physiopathology (LARF), University of Genoa, Italy
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McNally K, Hogg A, Loizou G. A Computational Workflow for Probabilistic Quantitative in Vitro to in Vivo Extrapolation. Front Pharmacol 2018; 9:508. [PMID: 29867507 PMCID: PMC5968095 DOI: 10.3389/fphar.2018.00508] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/27/2018] [Indexed: 11/30/2022] Open
Abstract
A computational workflow was developed to facilitate the process of quantitative in vitro to in vivo extrapolation (QIVIVE), specifically the translation of in vitro concentration-response to in vivo dose-response relationships and subsequent derivation of a benchmark dose value (BMD). The workflow integrates physiologically based pharmacokinetic (PBPK) modeling; global sensitivity analysis (GSA), Approximate Bayesian Computation (ABC) and Markov Chain Monte Carlo (MCMC) simulation. For a given set of in vitro concentration and response data the algorithm returns the posterior distribution of the corresponding in vivo, population-based dose-response values, for a given route of exposure. The novel aspect of the workflow is a rigorous statistical framework for accommodating uncertainty in both the parameters of the PBPK model (both parameter uncertainty and population variability) and in the structure of the PBPK model itself recognizing that the model is an approximation to reality. Both these sources of uncertainty propagate through the workflow and are quantified within the posterior distribution of in vivo dose for a fixed representative in vitro concentration. To demonstrate this process and for comparative purposes a similar exercise to previously published work describing the kinetics of ethylene glycol monoethyl ether (EGME) and its embryotoxic metabolite methoxyacetic acid (MAA) in rats was undertaken. The computational algorithm can be used to extrapolate from in vitro data to any organism, including human. Ultimately, this process will be incorporated into a user-friendly, freely available modeling platform, currently under development, that will simplify the process of QIVIVE.
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10
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Bessems JGM, Paini A, Gajewska M, Worth A. The margin of internal exposure (MOIE) concept for dermal risk assessment based on oral toxicity data - A case study with caffeine. Toxicology 2017; 392:119-129. [PMID: 28288858 PMCID: PMC5699174 DOI: 10.1016/j.tox.2017.03.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 10/26/2022]
Abstract
Route-to-route extrapolation is a common part of human risk assessment. Data from oral animal toxicity studies are commonly used to assess the safety of various but specific human dermal exposure scenarios. Using theoretical examples of various user scenarios, it was concluded that delineation of a generally applicable human dermal limit value is not a practicable approach, due to the wide variety of possible human exposure scenarios, including its consequences for internal exposure. This paper uses physiologically based kinetic (PBK) modelling approaches to predict animal as well as human internal exposure dose metrics and for the first time, introduces the concept of Margin of Internal Exposure (MOIE) based on these internal dose metrics. Caffeine was chosen to illustrate this approach. It is a substance that is often found in cosmetics and for which oral repeated dose toxicity data were available. A rat PBK model was constructed in order to convert the oral NOAEL to rat internal exposure dose metrics, i.e. the area under the curve (AUC) and the maximum concentration (Cmax), both in plasma. A human oral PBK model was constructed and calibrated using human volunteer data and adapted to accommodate dermal absorption following human dermal exposure. Use of the MOIE approach based on internal dose metrics predictions provides excellent opportunities to investigate the consequences of variations in human dermal exposure scenarios. It can accommodate within-day variation in plasma concentrations and is scientifically more robust than assuming just an exposure in mg/kg bw/day.
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Affiliation(s)
- Jos G M Bessems
- Directorate Health, Consumers and Reference Materials, European Commission, Joint Research Centre, Ispra, Italy
| | - Alicia Paini
- Directorate Health, Consumers and Reference Materials, European Commission, Joint Research Centre, Ispra, Italy.
| | - Monika Gajewska
- Directorate Health, Consumers and Reference Materials, European Commission, Joint Research Centre, Ispra, Italy
| | - Andrew Worth
- Directorate Health, Consumers and Reference Materials, European Commission, Joint Research Centre, Ispra, Italy
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11
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Li H, Zhang M, Vervoort J, Rietjens IMCM, van Ravenzwaay B, Louisse J. Use of physiologically based kinetic modeling-facilitated reverse dosimetry of in vitro toxicity data for prediction of in vivo developmental toxicity of tebuconazole in rats. Toxicol Lett 2016; 266:85-93. [PMID: 27890808 DOI: 10.1016/j.toxlet.2016.11.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 11/18/2016] [Accepted: 11/23/2016] [Indexed: 12/28/2022]
Abstract
Toxicological hazard and risk assessment largely rely on animal testing. For economic and ethical reasons, the development and validation of reliable alternative methods for these animal studies, such as in vitro assays, are urgently needed. In vitro concentration-response curves, however, need to be translated into in vivo dose-response curves for risk assessment purposes. In the present study, we translated in vitro concentration-response data of the antifungal compound tebuconazole, obtained in the ES-D3 cell differentiation assay, into predicted in vivo dose-response data for developmental toxicity using physiologically based kinetic (PBK) modeling-facilitated reverse dosimetry. Using the predicted in vivo dose-response data BMD(L)10 values for developmental toxicity in rat were calculated and compared with NOAEL values for developmental toxicity data in rats as reported in the literature. The results show that the BMDL10 value from predicted dose-response data are a reasonable approximation of the NOAEL values (ca. 3-fold difference). It is concluded that PBK modeling-facilitated reverse dosimetry of in vitro toxicity data is a promising tool to predict in vivo dose-response curves and may have the potential to define a point of departure for deriving safe exposure limits in risk assessment.
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Affiliation(s)
- Hequn Li
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Mengying Zhang
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Jacques Vervoort
- 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
| | - Bennard van Ravenzwaay
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands; Experimental Toxicology and Ecology, BASF SE, Z 470, 67056 Ludwigshafen, Germany
| | - Jochem Louisse
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
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13
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Abstract
The exponential growth of the Internet of Things and the global popularity and remarkable decline in cost of the mobile phone is driving the digital transformation of medical practice. The rapidly maturing digital, non-medical world of mobile (wireless) devices, cloud computing and social networking is coalescing with the emerging digital medical world of omics data, biosensors and advanced imaging which offers the increasingly realistic prospect of personalized medicine. Described as a potential “seismic” shift from the current “healthcare” model to a “wellness” paradigm that is predictive, preventative, personalized and participatory, this change is based on the development of increasingly sophisticated biosensors which can track and measure key biochemical variables in people. Additional key drivers in this shift are metabolomic and proteomic signatures, which are increasingly being reported as pre-symptomatic, diagnostic and prognostic of toxicity and disease. These advancements also have profound implications for toxicological evaluation and safety assessment of pharmaceuticals and environmental chemicals. An approach based primarily on human in vivo and high-throughput in vitro human cell-line data is a distinct possibility. This would transform current chemical safety assessment practice which operates in a human “data poor” to a human “data rich” environment. This could also lead to a seismic shift from the current animal-based to an animal-free chemical safety assessment paradigm.
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Affiliation(s)
- George D Loizou
- Health Risks, Health and Safety Laboratory, Health and Safety Executive Buxton, UK
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14
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Brinkmann M, Preuss TG, Hollert H. Advancing In Vitro-In Vivo Extrapolations of Mechanism-Specific Toxicity Data Through Toxicokinetic Modeling. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2016; 157:293-317. [PMID: 27619489 DOI: 10.1007/10_2015_5015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
International legislation, such as the European REACH regulation (registration, evaluation, authorization, and restriction of chemicals), mandates the assessment of potential risks of an ever-growing number of chemicals to the environment and human health. Although this legislation is considered one of the most important investments in consumer safety ever, the downside is that the current testing strategies within REACH rely on extensive animal testing. To address the ethical conflicts arising from these increased testing requirements, decision-makers, such as the European Chemicals Agency (ECHA), are committed to Russel and Burch's 3R principle (i.e., reduction, replacement, refinement) by demanding that animal experiments should be substituted with appropriate alternatives whenever possible. A potential solution of this dilemma might be the application of in vitro bioassays to estimate toxic effects using cells or cellular components instead of whole organisms. Although such assays are particularly useful to assess potential mechanisms of toxic action, scientists require appropriate methods to extrapolate results from the in vitro level to the situation in vivo. Toxicokinetic models are a straightforward means of bridging this gap. The present chapter describes different available options for in vitro-in vivo extrapolation (IVIVE) of mechanism-specific effects focused on fish species and also reviews the implications of confounding factors during the conduction of in vitro bioassays and their influence on the optimal choice of different dose metrics.
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Affiliation(s)
- Markus Brinkmann
- Department of Ecosystem Analysis, Institute for Environmental Research, Aachen Biology and Biotechnology - ABBt, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
| | | | - Henner Hollert
- Department of Ecosystem Analysis, Institute for Environmental Research, Aachen Biology and Biotechnology - ABBt, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
- College of Resources and Environmental Science, Chongqing University, 1 Tiansheng Road Beibei, Chongqing, 400715, China.
- College of Environmental Science and Engineering and State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, 1239 Siping Road, Shanghai, China.
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China.
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15
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Brinkmann M, Freese M, Pohlmann JD, Kammann U, Preuss TG, Buchinger S, Reifferscheid G, Beiermeister A, Hanel R, Hollert H. A physiologically based toxicokinetic (PBTK) model for moderately hydrophobic organic chemicals in the European eel (Anguilla anguilla). THE SCIENCE OF THE TOTAL ENVIRONMENT 2015. [PMID: 26218567 DOI: 10.1016/j.scitotenv.2015.07.046] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The European eel (Anguilla anguilla) is a facultatively catadromous fish species with a complex life cycle. Its current population status is alarming: recruitment has decreased drastically since the 1980s and its stock is still considered to be outside safe biological limits. Although there is no consensus on the reasons for this situation, it is currently thought to have resulted from a combination of different stressors, including anthropogenic contaminants. To deepen our understanding of the processes leading to the accumulation of lipophilic organic contaminants in yellow eels (i.e. the feeding, continental growth stage), we developed a physiologically based toxicokinetic model using our own data and values from the literature. Such models can predict the uptake and distribution of water-borne organic chemicals in the whole fish and in different tissues at any time during exposure. The predictive power of the model was tested against experimental data for six chemicals with n-octanol-water partitioning coefficient (log Kow) values ranging from 2.13-4.29. Model performance was excellent, with a root mean squared error of 0.28 log units. This model has the potential to help identify suitable habitats for restocking under eel management plans.
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Affiliation(s)
- Markus Brinkmann
- Department of Ecosystem Analysis, Institute for Environmental Research, ABBt - Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Marko Freese
- Thünen Institute of Fisheries Ecology, Hamburg, Germany
| | | | | | - Thomas G Preuss
- Environmental Biology and Chemodynamics, Institute for Environmental Research, ABBt - Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Sebastian Buchinger
- Federal Institute of Hydrology (BFG), Department G3: Biochemistry, Ecotoxicology, Koblenz, Germany
| | - Georg Reifferscheid
- Federal Institute of Hydrology (BFG), Department G3: Biochemistry, Ecotoxicology, Koblenz, Germany
| | | | | | - Henner Hollert
- Department of Ecosystem Analysis, Institute for Environmental Research, ABBt - Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China; College of Resources and Environmental Science, Chongqing University, Chongqing, China; Key Laboratory of Yangtze Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China.
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16
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Use of the ES-D3 cell differentiation assay, combined with the BeWo transport model, to predict relative in vivo developmental toxicity of antifungal compounds. Toxicol In Vitro 2015; 29:320-8. [DOI: 10.1016/j.tiv.2014.11.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 11/22/2014] [Accepted: 11/26/2014] [Indexed: 12/27/2022]
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17
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Prediction of in vivo developmental toxicity of all-trans-retinoic acid based on in vitro toxicity data and in silico physiologically based kinetic modeling. Arch Toxicol 2014; 89:1135-48. [DOI: 10.1007/s00204-014-1289-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 05/28/2014] [Indexed: 12/19/2022]
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18
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Brinkmann M, Eichbaum K, Buchinger S, Reifferscheid G, Bui T, Schäffer A, Hollert H, Preuss TG. Understanding receptor-mediated effects in rainbow trout: in vitro-in vivo extrapolation using physiologically based toxicokinetic models. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:3303-9. [PMID: 24548176 DOI: 10.1021/es4053208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The European REACH regulation requires the use of animal experimentation to assess the risk of industrial chemicals. However, the 3R principle (reduction, replacement, refinement) demands the use of suitable alternative test methods. Many dossiers submitted for the authorization of chemicals have attempted to provide the required data without performing new experiments, relying heavily on in silico methods; in vitro assays were scarcely used. We propose a methodology that uses physiologically based toxicokinetic (PBTK) models to extrapolate in vitro data to the in vivo level. We collected experimental results for in vitro and in vivo ethoxyresorufin-O-deethylase and vitellogenin induction following chemical exposure and compared those results with model predictions. We found that the predictive power of aqueous chemical concentrations was limited; median effect concentrations (EC50s) based on internal concentrations in fish correlated better with in vitro EC50s. Our data show that in vitro assays could offer a substitute for fish studies when combined with PBTK models.
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Affiliation(s)
- Markus Brinkmann
- Department of Ecosystem Analysis, RWTH Aachen University, Institute for Environmental Research , Worringerweg 1, 52074 Aachen, North Rhine-Westphalia, Germany
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19
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Hornberg JJ, Laursen M, Brenden N, Persson M, Thougaard AV, Toft DB, Mow T. Exploratory toxicology as an integrated part of drug discovery. Part II: Screening strategies. Drug Discov Today 2013; 19:1137-44. [PMID: 24374152 DOI: 10.1016/j.drudis.2013.12.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 11/18/2013] [Accepted: 12/18/2013] [Indexed: 12/31/2022]
Abstract
In an effort to reduce toxicity-related attrition, different strategies have been implemented throughout the pharmaceutical industry. Previously (in Part I), we have outlined our 'integrated toxicology' strategy, which aims to provide timely go/no-go decisions (fail early) but also to show a direction to the drug discovery teams (showing what will not fail). In this review (Part II of the series) we describe our compound testing strategies with respect to cardiovascular safety, hepatotoxicity, genotoxicity, immunotoxicity and exploratory in vivo toxicity. We discuss the in vitro, ex vivo and in vivo assays and models we employ to assess safety risks and optimize compound series during the drug discovery process, including their predictivity and the decisions they generate.
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Affiliation(s)
- Jorrit J Hornberg
- Department of Exploratory Toxicology, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark
| | - Morten Laursen
- Department of Exploratory Toxicology, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark
| | - Nina Brenden
- Department of Exploratory Toxicology, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark
| | - Mikael Persson
- Department of Exploratory Toxicology, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark
| | - Annemette V Thougaard
- Department of Exploratory Toxicology, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark
| | - Dorthe B Toft
- Department of Exploratory Toxicology, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark
| | - Tomas Mow
- Department of Exploratory Toxicology, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark.
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20
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Anadón A, Martínez MA, Castellano V, Martínez-Larrañaga MR. The role ofin vitromethods as alternatives to animals in toxicity testing. Expert Opin Drug Metab Toxicol 2013; 10:67-79. [DOI: 10.1517/17425255.2014.854329] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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21
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Ramirez T, Daneshian M, Kamp H, Bois FY, Clench MR, Coen M, Donley B, Fischer SM, Ekman DR, Fabian E, Guillou C, Heuer J, Hogberg HT, Jungnickel H, Keun HC, Krennrich G, Krupp E, Luch A, Noor F, Peter E, Riefke B, Seymour M, Skinner N, Smirnova L, Verheij E, Wagner S, Hartung T, van Ravenzwaay B, Leist M. Metabolomics in toxicology and preclinical research. ALTEX-ALTERNATIVES TO ANIMAL EXPERIMENTATION 2013; 30:209-25. [PMID: 23665807 DOI: 10.14573/altex.2013.2.209] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Metabolomics, the comprehensive analysis of metabolites in a biological system, provides detailed information about the biochemical/physiological status of a biological system, and about the changes caused by chemicals. Metabolomics analysis is used in many fields, ranging from the analysis of the physiological status of genetically modified organisms in safety science to the evaluation of human health conditions. In toxicology, metabolomics is the -omics discipline that is most closely related to classical knowledge of disturbed biochemical pathways. It allows rapid identification of the potential targets of a hazardous compound. It can give information on target organs and often can help to improve our understanding regarding the mode-of-action of a given compound. Such insights aid the discovery of biomarkers that either indicate pathophysiological conditions or help the monitoring of the efficacy of drug therapies. The first toxicological applications of metabolomics were for mechanistic research, but different ways to use the technology in a regulatory context are being explored. Ideally, further progress in that direction will position the metabolomics approach to address the challenges of toxicology of the 21st century. To address these issues, scientists from academia, industry, and regulatory bodies came together in a workshop to discuss the current status of applied metabolomics and its potential in the safety assessment of compounds. We report here on the conclusions of three working groups addressing questions regarding 1) metabolomics for in vitro studies 2) the appropriate use of metabolomics in systems toxicology, and 3) use of metabolomics in a regulatory context.
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Affiliation(s)
- Tzutzuy Ramirez
- BASF SE, Experimental Toxicology and Ecology, Ludwigshafen, Germany.
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22
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Assessment of an in vitro transport model using BeWo b30 cells to predict placental transfer of compounds. Arch Toxicol 2013; 87:1661-9. [DOI: 10.1007/s00204-013-1074-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 05/06/2013] [Indexed: 10/26/2022]
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23
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Péry ARR, Brochot C, Zeman FA, Mombelli E, Desmots S, Pavan M, Fioravanzo E, Zaldívar JM. Prediction of dose-hepatotoxic response in humans based on toxicokinetic/toxicodynamic modeling with or without in vivo data: a case study with acetaminophen. Toxicol Lett 2013; 220:26-34. [PMID: 23566899 DOI: 10.1016/j.toxlet.2013.03.032] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/23/2013] [Accepted: 03/25/2013] [Indexed: 02/04/2023]
Abstract
In the present legislations, the use of methods alternative to animal testing is explicitly encouraged, to use animal testing only 'as a last resort' or to ban it. The use of alternative methods to replace kinetics or repeated dose in vivo tests is a challenging issue. We propose here a strategy based on in vitro tests and QSAR (Quantitative Structure Activity Relationship) models to calibrate a dose-response model predicting hepatotoxicity. The dose response consists in calibrating and coupling a PBPK (physiologically-based pharmacokinetic) model with a toxicodynamic model for cell viability. We applied our strategy to acetaminophen and compared three different ways to calibrate the PBPK model: only with in vitro and in silico methods, using rat data or using all available data including data on humans. Some estimates of kinetic parameters differed substantially among the three calibration processes, but, at the end, the three models were quite comparable in terms of liver toxicity predictions and close to the usual range of human overdose. For the model based on alternative methods, the good adequation with the two other models resulted from an overestimated renal elimination rate which compensated for the underestimation of the metabolism rate. Our study points out that toxicokinetics/toxicodynamics approaches, based on alternative methods and modelling only, can predict in vivo liver toxicity with accuracy comparable to in vivo methods.
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Affiliation(s)
- Alexandre R R Péry
- Unité « Modèles pour l'écotoxicologie et la toxicologie » (METO), INERIS, Parc Alata BP2, 60550 Verneuil-en-Halatte, France.
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24
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Coecke S, Pelkonen O, Leite SB, Bernauer U, Bessems JG, Bois FY, Gundert-Remy U, Loizou G, Testai E, Zaldívar JM. Toxicokinetics as a key to the integrated toxicity risk assessment based primarily on non-animal approaches. Toxicol In Vitro 2012; 27:1570-7. [PMID: 22771339 DOI: 10.1016/j.tiv.2012.06.012] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 03/09/2012] [Accepted: 06/22/2012] [Indexed: 02/02/2023]
Abstract
Toxicokinetics (TK) is the endpoint that informs about the penetration into and fate within the body of a toxic substance, including the possible emergence of metabolites. Traditionally, the data needed to understand those phenomena have been obtained in vivo. Currently, with a drive towards non-animal testing approaches, TK has been identified as a key element to integrate the results from in silico, in vitro and already available in vivo studies. TK is needed to estimate the range of target organ doses that can be expected from realistic human external exposure scenarios. This information is crucial for determining the dose/concentration range that should be used for in vitro testing. Vice versa, TK is necessary to convert the in vitro results, generated at tissue/cell or sub-cellular level, into dose response or potency information relating to the entire target organism, i.e. the human body (in vitro-in vivo extrapolation, IVIVE). Physiologically based toxicokinetic modelling (PBTK) is currently regarded as the most adequate approach to simulate human TK and extrapolate between in vitro and in vivo contexts. The fact that PBTK models are mechanism-based which allows them to be 'generic' to a certain extent (various extrapolations possible) has been critical for their success so far. The need for high-quality in vitro and in silico data on absorption, distribution, metabolism as well as excretion (ADME) as input for PBTK models to predict human dose-response curves is currently a bottleneck for integrative risk assessment.
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Affiliation(s)
- Sandra Coecke
- ECVAM, Institute for Health & Consumer Protection, European Commission Joint Research Centre, 21027 Ispra (VA), Italy
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