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Nabi D, Beck AJ, Achterberg EP. Assessing Aquatic Baseline Toxicity of Plastic-Associated Chemicals: Development and Validation of the Target Plastic Model. J Chem Inf Model 2024; 64:6492-6505. [PMID: 39119989 DOI: 10.1021/acs.jcim.4c00574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
We developed a Target Plastic Model (TPM) to estimate the critical plastic burden of organic toxicants in five types of plastics, namely, polydimethylsiloxane (PDMS), polyoxymethylene (POM), polyacrylate (PA), low-density polyethylene (LDPE), and polyurethane ester (PU), following the Target Lipid Model (TLM) framework. By substituting the lipid-water partition coefficient in the TLM with plastic-water partition coefficients to create TPM, we demonstrated that the biomimetic nature of these plastic phases allows for the calculation of critical plastic burdens of toxicants, similar to the notion of critical lipid burdens in TLM. Following this approach, the critical plastic burdens of baseline (n = 115), less-inert (n = 73), and reactive (n = 75) toxicants ranged from 0.17 to 51.33, 0.04 to 26.62, and 1.00 × 10-6 to 6.78 × 10-4 mmol/kg of plastic, respectively. Our study showed that PDMS, PA, POM, PE, and PU are similar to biomembranes in mimicking the passive exchange of chemicals with the water phase. Using the TPM, median lethal concentration (LC50) values for fish exposed to baseline toxicants were predicted, and the results agreed with experimental values, with RMSE ranging from 0.311 to 0.538 log unit. Similarly, for the same data set of baseline toxicants, other widely used models, including the TLM (RMSE: 0.32-0.34), ECOSAR (RMSE: 0.35), and the Abraham Solvation Model (ASM; RMSE: 0.31), demonstrated comparable agreement between experimental and predicted values. For less inert chemicals, predictions were within a factor of 5 of experimental values. Comparatively, ASM and ECOSAR showed predictions within a factor of 2 and 3, respectively. The TLM based on phospholipid had predictions within a factor of 3 and octanol within a factor of 4, indicating that the TPM's performance for less inert chemicals is comparable to these established models. Unlike these methods, the TPM requires only the knowledge of plastic bound concentration for a given plastic phase to calculate baseline toxic units, bypassing the need for extensive LC50 and plastic-water partition coefficient data, which are often limited for emerging chemicals. Taken together, the TPM can provide valuable insights into the toxicities of chemicals associated with environmental plastic phases, assisting in selecting the best polymeric phase for passive sampling and designing better passive dosing techniques for toxicity experiments.
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Affiliation(s)
- Deedar Nabi
- GEOMAR Helmholtz Centre for Ocean Research Kiel Wischhofstr. 1-3, 24148 Kiel, Germany
- Institute of Environmental Science and Engineering (IESE), School of Civil and Environmental Engineering (SCEE), National University of Sciences and Technology (NUST), H-12, Islamabad, Pakistan
| | - Aaron J Beck
- GEOMAR Helmholtz Centre for Ocean Research Kiel Wischhofstr. 1-3, 24148 Kiel, Germany
| | - Eric P Achterberg
- GEOMAR Helmholtz Centre for Ocean Research Kiel Wischhofstr. 1-3, 24148 Kiel, Germany
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2
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Nicol B, Vandenbossche-Goddard E, Thorpe C, Newman R, Patel H, Yates D. A workflow to practically apply true dose considerations to in vitro testing for next generation risk assessment. Toxicology 2024; 505:153826. [PMID: 38719068 DOI: 10.1016/j.tox.2024.153826] [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: 03/05/2024] [Revised: 04/22/2024] [Accepted: 05/01/2024] [Indexed: 05/14/2024]
Abstract
With the move away from safety testing assessment based on data generated in experimental animals the concept of Next Generation Risk Assessment (NGRA) has arisen which instead uses data from in silico and in vitro models. A key uncertainty in risk assessment is the actual dose of test chemical at the target site, and therefore surrogate dose metrics, such as nominal concentration in test media are used to describe in vitro effect (or no-effect) doses. The reliability and accuracy of the risk assessment therefore depends largely on our ability to understand and characterise the relationship between the dose metrics used and the actual biologically effective dose at the target site. The objective of this publication is to use 40 case study chemicals to illustrate how in vitro dose considerations can be applied to characterise the "true dose" and build confidence in the understanding of the biologically effective dose in in vitro test systems for the determination e.g. points of departure (PoDs) for NGRA. We propose a workflow that can be applied to assess whether the nominal test concentration can be considered a conservative dose metric for use in NGRA. The workflow examines the implications of volatility, stability, hydrophobicity, binding to plastic and serum, solubility, and the potential use of in silico models for some of these parameters. For the majority of the case study chemicals we found that the use of nominal concentrations in risk assessment would result in conservative decision making. However, for serval chemicals a potential for underestimation of the risk in humans in vivo based on in vitro nominal effect concentrations was identified, and approaches for refinement by characterisation of the actual effect concentration are proposed.
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Affiliation(s)
- Beate Nicol
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedford, Bedfordshire MK44 1LQ, UK
| | - Evita Vandenbossche-Goddard
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedford, Bedfordshire MK44 1LQ, UK.
| | - Charlotte Thorpe
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedford, Bedfordshire MK44 1LQ, UK
| | | | - Hiral Patel
- Charles River Laboratories, Cambridgeshire CB10 1XL, UK
| | - Dawn Yates
- Charles River Laboratories, Cambridgeshire CB10 1XL, UK
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3
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Huchthausen J, Braasch J, Escher BI, König M, Henneberger L. Effects of Chemicals in Reporter Gene Bioassays with Different Metabolic Activities Compared to Baseline Toxicity. Chem Res Toxicol 2024; 37:744-756. [PMID: 38652132 PMCID: PMC11110108 DOI: 10.1021/acs.chemrestox.4c00017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/05/2024] [Accepted: 04/09/2024] [Indexed: 04/25/2024]
Abstract
High-throughput cell-based bioassays are used for chemical screening and risk assessment. Chemical transformation processes caused by abiotic degradation or metabolization can reduce the chemical concentration or, in some cases, lead to the formation of more toxic transformation products. Unaccounted loss processes may falsify the bioassay results. Capturing the formation and effects of transformation products is important for relating the in vitro effects to in vivo. Reporter gene cell lines are believed to have low metabolic activity, but inducibility of cytochrome P450 (CYP) enzymes has been reported. Baseline toxicity is the minimal toxicity a chemical can have and is caused by the incorporation of the chemical into cell membranes. In the present study, we improved an existing baseline toxicity model based on a newly defined critical membrane burden derived from freely dissolved effect concentrations, which are directly related to the membrane concentration. Experimental effect concentrations of 94 chemicals in three bioassays (AREc32, ARE-bla and GR-bla) were compared with baseline toxicity by calculating the toxic ratio (TR). CYP activities of all cell lines were determined by using fluorescence-based assays. Only ARE-bla showed a low basal CYP activity and inducibility and AREc32 showed a low inducibility. Overall cytotoxicity was similar in all three assays despite the different metabolic activities indicating that chemical metabolism is not relevant for the cytotoxicity of the tested chemicals in these assays. Up to 28 chemicals showed specific cytotoxicity with TR > 10 in the bioassays, but baseline toxicity could explain the effects of the majority of the remaining chemicals. Seven chemicals showed TR < 0.1 indicating inaccurate physicochemical properties or experimental artifacts like chemical precipitation, volatilization, degradation, or other loss processes during the in vitro bioassay. The new baseline model can be used not only to identify specific cytotoxicity mechanisms but also to identify potential problems in the experimental performance or evaluation of the bioassay and thus improve the quality of the bioassay data.
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Affiliation(s)
- Julia Huchthausen
- Department
of Cell Toxicology, Helmholtz Centre for
Environmental Research − UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Jenny Braasch
- Department
of Cell Toxicology, Helmholtz Centre for
Environmental Research − UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Beate I. Escher
- Department
of Cell Toxicology, Helmholtz Centre for
Environmental Research − UFZ, Permoserstr. 15, 04318 Leipzig, Germany
- Environmental
Toxicology, Department of Geosciences, Eberhard
Karls University Tübingen, 72076 Tübingen, Germany
| | - Maria König
- Department
of Cell Toxicology, Helmholtz Centre for
Environmental Research − UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Luise Henneberger
- Department
of Cell Toxicology, Helmholtz Centre for
Environmental Research − UFZ, Permoserstr. 15, 04318 Leipzig, Germany
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4
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Qin W, Henneberger L, Glüge J, König M, Escher BI. Baseline Toxicity Model to Identify the Specific and Nonspecific Effects of Per- and Polyfluoroalkyl Substances in Cell-Based Bioassays. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:5727-5738. [PMID: 38394616 PMCID: PMC10993398 DOI: 10.1021/acs.est.3c09950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 02/11/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024]
Abstract
High-throughput screening is a strategy to identify potential adverse outcome pathways (AOP) for thousands of per- and polyfluoroalkyl substances (PFAS) if the specific effects can be distinguished from nonspecific effects. We hypothesize that baseline toxicity may serve as a reference to determine the specificity of the cell responses. Baseline toxicity is the minimum (cyto)toxicity caused by the accumulation of chemicals in cell membranes, which disturbs their structure and function. A mass balance model linking the critical membrane concentration for baseline toxicity to nominal (i.e., dosed) concentrations of PFAS in cell-based bioassays yielded separate baseline toxicity prediction models for anionic and neutral PFAS, which were based on liposome-water distribution ratios as the sole model descriptors. The specificity of cell responses to 30 PFAS on six target effects (activation of peroxisome proliferator-activated receptor (PPAR) gamma, aryl hydrocarbon receptor, oxidative stress response, and neurotoxicity in own experiments, and literature data for activation of several PPARs and the estrogen receptor) were assessed by comparing effective concentrations to predicted baseline toxic concentrations. HFPO-DA, HFPO-DA-AS, and PFMOAA showed high specificity on PPARs, which provides information on key events in AOPs relevant to PFAS. However, PFAS were of low specificity in the other experimentally evaluated assays and others from the literature. Even if PFAS are not highly specific for certain defined targets but disturb many toxicity pathways with low potency, such effects are toxicologically relevant, especially for hydrophobic PFAS and because PFAS are highly persistent and cause chronic effects. This implicates a heightened need for the risk assessment of PFAS mixtures because nonspecific effects behave concentration-additive in mixtures.
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Affiliation(s)
- Weiping Qin
- Department
of Cell Toxicology, UFZ−Helmholtz
Centre for Environmental Research, Leipzig 04318, Germany
- Environmental
Toxicology, Department of Geosciences, Eberhard
Karls University Tübingen, Schnarrenbergstr. 94-96, Tübingen DE-72076, Germany
| | - Luise Henneberger
- Department
of Cell Toxicology, UFZ−Helmholtz
Centre for Environmental Research, Leipzig 04318, Germany
| | - Juliane Glüge
- Department
of Cell Toxicology, UFZ−Helmholtz
Centre for Environmental Research, Leipzig 04318, Germany
- Institute
of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Zürich 8092, Switzerland
| | - Maria König
- Department
of Cell Toxicology, UFZ−Helmholtz
Centre for Environmental Research, Leipzig 04318, Germany
| | - Beate I. Escher
- Department
of Cell Toxicology, UFZ−Helmholtz
Centre for Environmental Research, Leipzig 04318, Germany
- Environmental
Toxicology, Department of Geosciences, Eberhard
Karls University Tübingen, Schnarrenbergstr. 94-96, Tübingen DE-72076, Germany
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5
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Boone KS, Di Toro DM, Davis CW, Parkerton TF, Redman A. In Silico Acute Aquatic Hazard Assessment and Prioritization Using a Grouped Target Site Model: A Case Study of Organic Substances Reported in Permian Basin Hydraulic Fracturing Operations. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2024. [PMID: 38415890 DOI: 10.1002/etc.5826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/17/2023] [Accepted: 01/15/2024] [Indexed: 02/29/2024]
Abstract
Hydraulic fracturing (HF) is commonly used to enhance onshore recovery of oil and gas during production. This process involves the use of a variety of chemicals to support the physical extraction of oil and gas, maintain appropriate conditions downhole (e.g., redox conditions, pH), and limit microbial growth. The diversity of chemicals used in HF presents a significant challenge for risk assessment. The objective of the present study is to establish a transparent, reproducible procedure for estimating 5th percentile acute aquatic hazard concentrations (e.g., acute hazard concentration 5th percentiles [HC5s]) for these substances and validating against existing toxicity data. A simplified, grouped target site model (gTSM) was developed using a database (n = 1696) of diverse compounds with known mode of action (MoA) information. Statistical significance testing was employed to reduce model complexity by combining 11 discrete MoAs into three general hazard groups. The new model was trained and validated using an 80:20 allocation of the experimental database. The gTSM predicts toxicity using a combination of target site water partition coefficients and hazard group-based critical target site concentrations. Model performance was comparable to the original TSM using 40% fewer parameters. Model predictions were judged to be sufficiently reliable and the gTSM was further used to prioritize a subset of reported Permian Basin HF substances for risk evaluation. The gTSM was applied to predict hazard groups, species acute toxicity, and acute HC5s for 186 organic compounds (neutral and ionic). Toxicity predictions and acute HC5 estimates were validated against measured acute toxicity data compiled for HF substances. This case study supports the gTSM as an efficient, cost-effective computational tool for rapid aquatic hazard assessment of diverse organic chemicals. Environ Toxicol Chem 2024;00:1-12. © 2024 ExxonMobil Petroleum and Chemical BV. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
- Kathleen S Boone
- Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware, USA
| | - Dominic M Di Toro
- Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware, USA
| | - Craig W Davis
- ExxonMobil Biomedical Sciences, Annandale, New Jersey, USA
| | | | - Aaron Redman
- ExxonMobil Biomedical Sciences, Annandale, New Jersey, USA
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6
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Fischer FC, Ludtke S, Thackray C, Pickard HM, Haque F, Dassuncao C, Endo S, Schaider L, Sunderland EM. Binding of Per- and Polyfluoroalkyl Substances (PFAS) to Serum Proteins: Implications for Toxicokinetics in Humans. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:1055-1063. [PMID: 38166384 PMCID: PMC11149785 DOI: 10.1021/acs.est.3c07415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a diverse class of highly persistent anthropogenic chemicals that are detectable in the serum of most humans. PFAS exposure has been associated with many adverse effects on human health including immunotoxicity, increased risk of certain cancers, and metabolic disruption. PFAS binding to the most abundant blood serum proteins (human serum albumin [HSA] and globulins) is thought to affect transport to active sites, toxicity, and elimination half-lives. However, few studies have investigated the competitive binding of PFAS to these proteins in human serum. Here, we use C18 solid-phase microextraction fibers to measure HSA-water and globulin-water distribution coefficients (DHSA/w, Dglob/w) for PFAS with carbon chains containing 4 to 13 perfluorinated carbons (ηpfc = 4-13) and several functional head-groups. PFAS with ηpfc < 7 were highly bound to HSA relative to globulins, whereas PFAS with ηpfc ≥ 7 showed a greater propensity for binding to globulins. Experimentally measured DHSA/w and Dglob/w and concentrations of serum proteins successfully predicted the variability in PFAS binding in human serum. We estimated that the unbound fraction of serum PFAS varied by up to a factor of 2.5 among individuals participating in the 2017-2018 U.S. National Health and Nutrition Examination Survey. These results suggest that serum HSA and globulins are important covariates for epidemiological studies aimed at understanding the effects of PFAS exposure.
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Affiliation(s)
- Fabian Christoph Fischer
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Sophia Ludtke
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Colin Thackray
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Heidi M Pickard
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Faiz Haque
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Clifton Dassuncao
- Eastern Research Group, Inc. (ERG), Arlington, Virginia 22201, United States
| | - Satoshi Endo
- National Institute for Environmental Studies (NIES), Health and Environmental Risk Division, Onogawa 16-2, Tsukuba, Ibaraki 305-8506, Japan
| | - Laurel Schaider
- Silent Spring Institute, Newton, Massachusetts 02460, United States
| | - Elsie M Sunderland
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Harvard University, Cambridge, Massachusetts 02138, United States
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7
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Ulrich N, Böhme A, Strobel AB, Egert T. Predicting partitioning from low density polyethylene to blood and adipose tissue by linear solvation energy relationship models. J Biomed Mater Res B Appl Biomater 2023; 111:2044-2054. [PMID: 37498141 DOI: 10.1002/jbm.b.35304] [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: 02/02/2023] [Revised: 06/15/2023] [Accepted: 07/12/2023] [Indexed: 07/28/2023]
Abstract
The variety of polymers utilized in medical devices demands for testing of extractables and leachables according to ISO 10993-18:2020 in combination with ISO 10993-1:2018. The extraction of the materials involves the use of organic solvents as well as aqueous buffers to cover a wide range of polarity and pH-values, respectively. To estimate patient exposure to chemicals leaching from a polymer in direct body contact, simulating solvents are applied to best mimic the solubilization and partitioning behavior of the related tissue or body fluid. Here we apply linear solvation energy relationship (LSER) models to predict blood/water and adipose tissue/water partition coefficients. We suggest this predictive approach to project levels of potential leachables, design extraction experiments, and to identify the optimal composition of simulating extraction solvents. We compare our predictions to LSER predictions for commonly applied surrogates like ethanol/water mixtures, butanol, and octanol as well as olive oil, butanone, 1,4-dioxane for blood and adipose tissue, respectively. We therefore selected a set of 26 experimentally determined blood/water partition coefficients and 33 adipose tissue/water partition coefficients, where we demonstrate that based on the root mean squared error rmse the LSER approach performs better than surrogates like octanol or butanol and equally well as 60:40 ethanol/water for blood. For adipose tissue/water partitioning, the experimentally determined octanol/water partition coefficient performs best but the rmse is at the same range as our LSER approach based on experimentally determined descriptors. Further, we applied our approach for 248 extractables where we calculated blood/low density polyethylene (LDPE) and adipose tissue/LDPE partition coefficients. By this approach, we successfully identified chemicals of potential interest to a toxicological evaluation based on the total risk score.
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Affiliation(s)
- Nadin Ulrich
- Department of Ecological Chemistry, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Alexander Böhme
- Department of Ecological Chemistry, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | | | - Thomas Egert
- Boehringer Ingelheim Pharma GmbH, Ingelheim, Germany
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8
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Chen M, Du R, Zhang T, Li C, Bao W, Xin F, Hou S, Yang Q, Chen L, Wang Q, Zhu A. The Application of a Physiologically Based Toxicokinetic Model in Health Risk Assessment. TOXICS 2023; 11:874. [PMID: 37888724 PMCID: PMC10611306 DOI: 10.3390/toxics11100874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/17/2023] [Accepted: 10/19/2023] [Indexed: 10/28/2023]
Abstract
Toxicokinetics plays a crucial role in the health risk assessments of xenobiotics. Classical compartmental models are limited in their ability to determine chemical concentrations in specific organs or tissues, particularly target organs or tissues, and their limited interspecific and exposure route extrapolation hinders satisfactory health risk assessment. In contrast, physiologically based toxicokinetic (PBTK) models quantitatively describe the absorption, distribution, metabolism, and excretion of chemicals across various exposure routes and doses in organisms, establishing correlations with toxic effects. Consequently, PBTK models serve as potent tools for extrapolation and provide a theoretical foundation for health risk assessment and management. This review outlines the construction and application of PBTK models in health risk assessment while analyzing their limitations and future perspectives.
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Affiliation(s)
- Mengting Chen
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China
| | - Ruihu Du
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, China
| | - Tao Zhang
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, China
| | - Chutao Li
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China
| | - Wenqiang Bao
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China
| | - Fan Xin
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China
| | - Shaozhang Hou
- Department of Pathology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan 750004, China
| | - Qiaomei Yang
- Department of Gynecology, Fujian Maternity and Child Health Hospital (Fujian Obstetrics and Gynecology Hospital), Fuzhou 350001, China
| | - Li Chen
- Department of Gynecology, Fujian Maternity and Child Health Hospital (Fujian Obstetrics and Gynecology Hospital), Fuzhou 350001, China
| | - Qi Wang
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, China
- Key Laboratory of State Administration of Traditional Chinese Medicine for Compatibility Toxicology, Beijing 100191, China
- Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, China
| | - An Zhu
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China
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9
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Miller-Holt J, Behrsing H, Crooks I, Curren R, Demir K, Gafner J, Gillman G, Hollings M, Leverette R, Oldham M, Simms L, Stankowski LF, Thorne D, Wieczorek R, Moore MM. Key challenges for in vitro testing of tobacco products for regulatory applications: Recommendations for dosimetry. Drug Test Anal 2023; 15:1175-1188. [PMID: 35830202 PMCID: PMC9897201 DOI: 10.1002/dta.3344] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 07/02/2022] [Accepted: 07/05/2022] [Indexed: 02/05/2023]
Abstract
The Institute for In Vitro Sciences (IIVS) is sponsoring a series of workshops to develop recommendations for optimal scientific and technical approaches for conducting in vitro assays to assess potential toxicity within and across tobacco and various next-generation products (NGPs) including heated tobacco products (HTPs) and electronic nicotine delivery systems (ENDSs). This publication was developed by a working group of the workshop members in conjunction with the sixth workshop in that series entitled "Dosimetry for conducting in vitro evaluations" and focuses on aerosol dosimetry for aerosol exposure to combustible cigarettes, HTP, and ENDS aerosolized tobacco products and summarizes the key challenges as well as documenting areas for future research.
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Affiliation(s)
| | - Holger Behrsing
- Institute for In Vitro Sciences, Gaithersburg, Maryland, USA
| | - Ian Crooks
- Consumer Product Safety, British American Tobacco, Southampton, UK
| | - Rodger Curren
- Institute for In Vitro Sciences, Gaithersburg, Maryland, USA
| | - Kubilay Demir
- Regulatory Science, JUUL Labs Inc., 1000 F Street NW, Washington D.C. 20004, USA
| | - Jeremie Gafner
- Scientific & Regulatory Affairs, JT International SA, Geneva, Switzerland
| | - Gene Gillman
- Regulatory Science, JUUL Labs Inc., 1000 F Street NW, Washington D.C. 20004, USA
| | - Michael Hollings
- Genetic Toxicology, Labcorp Early Development Laboratories Ltd., Harrogate, UK
| | - Robert Leverette
- Scientific & Regulatory Affairs, RAI Services Company, Winston-Salem, North Carolina, USA
| | - Michael Oldham
- Regulatory Science, JUUL Labs Inc., 1000 F Street NW, Washington D.C. 20004, USA
| | - Liam Simms
- Group Science and Regulatory Affairs, Imperial Brands, Bristol, UK
| | - Leon F. Stankowski
- Genetic and In Vitro Toxicology, Charles River Laboratories–Skokie, Skokie, Illinois, USA
| | - David Thorne
- Consumer Product Safety, British American Tobacco, Southampton, UK
| | - Roman Wieczorek
- Group Science and Regulatory Affairs, Reemtsma Cigarettenfabriken GmbH, an Imperial Brands PLC Company, Hamburg, Germany
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10
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Droge STJ, Hodges G, Bonnell M, Gutsell S, Roberts J, Teixeira A, Barrett EL. Using membrane-water partition coefficients in a critical membrane burden approach to aid the identification of neutral and ionizable chemicals that induce acute toxicity below narcosis levels. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:621-647. [PMID: 36779707 DOI: 10.1039/d2em00391k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The risk assessment of thousands of chemicals used in our society benefits from adequate grouping of chemicals based on the mode and mechanism of toxic action (MoA). We measure the phospholipid membrane-water distribution ratio (DMLW) using a chromatographic assay (IAM-HPLC) for 121 neutral and ionized organic chemicals and screen other methods to derive DMLW. We use IAM-HPLC based DMLW as a chemical property to distinguish between baseline narcosis and specific MoA, for reported acute toxicity endpoints on two separate sets of chemicals. The first set comprised 94 chemicals of US EPA's acute fish toxicity database: 47 categorized as narcosis MoA, 27 with specific MoA, and 20 predominantly ionic chemicals with mostly unknown MoA. The narcosis MoA chemicals clustered around the median narcosis critical membrane burden (CMBnarc) of 140 mmol kg-1 lipid, with a lower limit of 14 mmol kg-1 lipid, including all chemicals labelled Narcosis_I and Narcosis_II. This maximum 'toxic ratio' (TR) between CMBnarc and the lower limit narcosis endpoint is thus 10. For 23/28 specific MoA chemicals a TR >10 was derived, indicative of a specific adverse effect pathway related to acute toxicity. For 10/12 cations categorized as "unsure amines", the TR <10 suggests that these affect fish via narcosis MoA. The second set comprised 29 herbicides, including 17 dissociated acids, and evaluated the TR for acute toxic effect concentrations to likely sensitive aquatic plant species (green algae and macrophytes Lemna and Myriophyllum), and non-target animal species (invertebrates and fish). For 21/29 herbicides, a TR >10 indicated a specific toxic mode of action other than narcosis for at least one of these aquatic primary producers. Fish and invertebrate TRs were mostly <10, particularly for neutral herbicides, but for acidic herbicides a TR >10 indicated specific adverse effects in non-target animals. The established critical membrane approach to derive the TR provides for useful contribution to the weight of evidence to bin a chemical as having a narcosis MoA or less likely to have acute toxicity caused by a more specific adverse effect pathway. After proper calibration, the chromatographic assay provides consistent and efficient experimental input for both neutral and ionizable chemicals to this approach.
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Affiliation(s)
- Steven T J Droge
- Department of Freshwater and Marine Ecology (FAME), Institute for Biodiversity and Ecosystem Dynamics (IBED), Universiteit van Amsterdam (UvA), Science Park 904, 1098XH Amsterdam, The Netherlands.
| | - Geoff Hodges
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire, UK
| | - Mark Bonnell
- Environment and Climate Change Canada, Ecological Assessment Division, Science and Risk Assessment Directorate, Gatineau, Quebec, Canada
| | - Steve Gutsell
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire, UK
| | - Jayne Roberts
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire, UK
| | - Alexandre Teixeira
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire, UK
| | - Elin L Barrett
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire, UK
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11
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Saunders LJ, Nichols JW. Models Used to Predict Chemical Bioaccumulation in Fish from in Vitro Biotransformation Rates Require Accurate Estimates of Blood-Water Partitioning and Chemical Volume of Distribution. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2023; 42:33-45. [PMID: 36282023 PMCID: PMC10824487 DOI: 10.1002/etc.5503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/11/2022] [Accepted: 10/15/2022] [Indexed: 06/16/2023]
Abstract
Methods for extrapolating measured in vitro intrinsic clearance to a whole-body biotransformation rate constant (kB ) have been developed to support modeled bioaccumulation assessments for fish. The inclusion of extrapolated kB values into existing bioaccumulation models improves the prediction of chemical bioconcentration factors (BCFs), but there remains a tendency for these methods to overestimate BCFs relative to measured values. Therefore, a need exists to evaluate the extrapolation procedure to assess potential sources of error in predicted kB values. We examined how three different approaches (empirically based, composition based, and polyparameter linear free energy relationships [ppLFERs]) used to predict chemical partitioning in vitro (liver S9 system; KS9W ), in blood (KBW ), and in whole fish tissues (KFW ) impact the prediction of a chemical's hepatic clearance binding term (fU ) and apparent volume of distribution (VD ), both of which factor into the calculation of kB and the BCF. Each approach yielded different KS9W , KBW , and KFW values, but resulted in fU values that were of similar magnitude and remained relatively constant at log octanol-water partition ratios (KOW ) greater than 4. This is because KBW and KS9W values predicted by any given approach exhibit a similar dependence on log KOW (i.e., regression slope), which results in a cancelation of "errors" when fU is calculated. In contrast, differences in KBW values predicted by the three approaches translate to differences in VD , and by extension kB and the BCF, which become most apparent at log KOW greater than 6. There is a need to collect KBW and VD data for hydrophobic chemicals in fish that can be used to evaluate and improve existing partitioning prediction approaches in extrapolation models for fish. Environ Toxicol Chem 2023;42:33-45. © 2022 SETAC.
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Affiliation(s)
- Leslie J. Saunders
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
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12
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Dimitrijevic D, Fabian E, Nicol B, Funk-Weyer D, Landsiedel R. Toward Realistic Dosimetry In Vitro: Determining Effective Concentrations of Test Substances in Cell Culture and Their Prediction by an In Silico Mass Balance Model. Chem Res Toxicol 2022; 35:1962-1973. [PMID: 36264934 PMCID: PMC9682521 DOI: 10.1021/acs.chemrestox.2c00128] [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] [Indexed: 01/09/2023]
Abstract
Nominal concentrations (CNom) in cell culture media are routinely used to define concentration-effect relationships in the in vitro toxicology. The actual concentration in the medium (CMedium) can be affected by adsorption processes, evaporation, or degradation of chemicals. Therefore, we measured the total and free concentration of 12 chemicals, covering a wide range of lipophilicity (log KOW -0.07-6.84), in the culture medium (CMedium) and cells (CCell) after incubation with Balb/c 3T3 cells for up to 48 h. Measured values were compared to predictions using an as yet unpublished in silico mass balance model that combined relevant equations from similar models published by others. The total CMedium for all chemicals except tamoxifen (TAM) were similar to the CNom. This was attributed to the cellular uptake of TAM and accumulation into lysosomes. The free (i.e., unbound) CMedium for the low/no protein binding chemicals were similar to the CNom, whereas values of all moderately to highly protein-bound chemicals were less than 30% of the CNom. Of the 12 chemicals, the two most hydrophilic chemicals, acetaminophen (APAP) and caffeine (CAF), were the only ones for which the CCell was the same as the CNom. The CCell for all other chemicals tended to increase over time and were all 2- to 274-fold higher than CNom. Measurements of CCytosol, using a digitonin method to release cytosol, compared well with CCell (using a freeze-thaw method) for four chemicals (CAF, APAP, FLU, and KET), indicating that both methods could be used. The mass balance model predicted the total CMedium within 30% of the measured values for 11 chemicals. The free CMedium of all 12 chemicals were predicted within 3-fold of the measured values. There was a poorer prediction of CCell values, with a median overprediction of 3- to 4-fold. In conclusion, while the number of chemicals in the study is limited, it demonstrates the large differences between CNom and total and free CMedium and CCell, which were also relatively well predicted by the mass balance model.
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Affiliation(s)
- Dunja Dimitrijevic
- Free
University of Berlin, Institute of Pharmacy, Pharmacology and Toxicology, Königin-Luise-Straße
2−4, 14195Berlin, Germany
| | - Eric Fabian
- BASF
SE, Experimental Toxicology and Ecology, Carl-Bosch-Straße 38, 67056Ludwigshafen am Rhein, Germany
| | - Beate Nicol
- Safety
& Environmental Assurance Centre, Unilever
U.K., Sharnbrook, MK44 ILQBedford, United Kingdom
| | - Dorothee Funk-Weyer
- BASF
SE, Experimental Toxicology and Ecology, Carl-Bosch-Straße 38, 67056Ludwigshafen am Rhein, Germany
| | - Robert Landsiedel
- Free
University of Berlin, Institute of Pharmacy, Pharmacology and Toxicology, Königin-Luise-Straße
2−4, 14195Berlin, Germany,BASF
SE, Experimental Toxicology and Ecology, Carl-Bosch-Straße 38, 67056Ludwigshafen am Rhein, Germany,. Fax: +49 621 60-58134
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13
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Ruan Y, Sun H, Lu Y, Zhang Y, Xu J, Zhu H, He Y. Evaluating phospholipid- and protein-water partitioning of two groups of chemicals of emerging concern: Diastereo- and enantioselectivity. JOURNAL OF HAZARDOUS MATERIALS 2022; 430:128499. [PMID: 35739679 DOI: 10.1016/j.jhazmat.2022.128499] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 01/19/2022] [Accepted: 02/12/2022] [Indexed: 06/15/2023]
Abstract
The partitioning between phospholipids/proteins and water can be used to predict the bioaccumulation potential of chemicals with better accuracy compared with n-octanol-water partition coefficient. However, such partitioning is poorly understood for chiral chemicals, many of which exhibit differential bioaccumulation and toxicity potential between enantiomers. In this study, the enantiospecific liposome-water and bovine serum albumin (BSA)-water partition coefficients (Klip/w and KBSA/w, determined at 25 ℃ and 37 ℃, respectively) were measured by equilibrium dialysis for α-, β-, and γ-hexabromocyclododecane (HBCD) and three β-blockers (propranolol, metoprolol, and sotalol). Raman and fluorescence analyses and molecular docking were conducted to provide additional insights into the partitioning process. Results showed α- and β-HBCD displayed stronger enantioselective partitioning to liposomes with the (-)-form, while (-)-α-HBCD, R-(+)-propranolol, R-(+)-metoprolol, and E2-sotalol favored partitioning to BSA compared with their antipodes. Raman spectra revealed α- and γ-HBCD enhanced and reduced the organization of liposome acyl chains, respectively, and polar interactions enhanced the liposome partitioning of β-blockers. Fluorescence spectra indicated the changed tryptophan microenvironment might influence the BSA steric effect toward HBCD, and electrostatic interactions dominated the formation of BSA-β-blocker complexes. Molecular docking results supported the difference in the thermodynamic nature of interaction between the studied enantiomers and BSA.
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Affiliation(s)
- Yuefei Ruan
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; State Key Laboratory of Marine Pollution (SKLMP), Department of Chemistry, Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), City University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Hongwen Sun
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
| | - Yichun Lu
- School of Energy and Environment, City University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Yanwei Zhang
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Jiayao Xu
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Hongkai Zhu
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Yuhe He
- School of Energy and Environment, City University of Hong Kong, Hong Kong Special Administrative Region of China
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14
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Endo S. Applicability Domain of Polyparameter Linear Free Energy Relationship Models Evaluated by Leverage and Prediction Interval Calculation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:5572-5579. [PMID: 35420030 PMCID: PMC9069697 DOI: 10.1021/acs.est.2c00865] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Polyparameter linear free energy relationships (PP-LFERs) are accurate and robust models employed to predict equilibrium partition coefficients (K) of organic chemicals. The accuracy of predictions by a PP-LFER depends on the composition of the respective calibration data set. Generally, extrapolation outside the domain defined by the calibration data is likely to be less accurate than interpolation. In this study, the applicability domain (AD) of PP-LFERs was systematically evaluated by calculating the leverage (h) and prediction interval (PI). Repeated simulations with experimental data showed that the root mean squared error of predictions increased with h. However, the analysis also showed that PP-LFERs calibrated with a large number (e.g., 100) of training data were highly robust against extrapolation error. For such PP-LFERs, the common definition of extrapolation (h > 3 hmean, where hmean is the mean h of all training compounds) may be excessively strict. Alternatively, the PI is proposed as a metric to define the AD of PP-LFERs, as it provides a concrete estimate of the error range that agrees well with the observed errors, even for extreme extrapolations. Additionally, published PP-LFERs were evaluated in terms of their AD using the new concept of AD probes, which indicated the varying predictive performance of PP-LFERs in the existing literature for environmentally relevant compounds.
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Affiliation(s)
- Satoshi Endo
- Health
and Environmental Risk Division, National
Institute for Environmental Studies (NIES), Onogawa 16-2, Tsukuba, 305-8506 Ibaraki, Japan
- Graduate
School of Engineering, Osaka City University, Sugimoto 3-3-138, Sumiyoshi, 558-8585 Osaka, Japan
- . Phone: ++81-29-850-2695. Fax: ++81-29-850-2870
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15
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Garoche C, Boulahtouf A, Grimaldi M, Chiavarina B, Toporova L, den Broeder MJ, Legler J, Bourguet W, Balaguer P. Interspecies Differences in Activation of Peroxisome Proliferator-Activated Receptor γ by Pharmaceutical and Environmental Chemicals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:16489-16501. [PMID: 34843233 DOI: 10.1021/acs.est.1c04318] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Endocrine disrupting chemicals (EDCs) are able to deregulate the hormone system, notably through interactions with nuclear receptors (NRs). The mechanisms of action and biological effects of many EDCs have mainly been tested on human and mouse but other species such as zebrafish and xenopus are increasingly used as a model to study the effects of EDCs. Among NRs, peroxisome proliferator-activated receptor γ (PPARγ) is a main target of EDCs, for which most experimental data have been obtained from human and mouse models. To assess interspecies differences, we tested known human PPARγ ligands on reporter cell lines expressing either human, mouse, zebrafish, or xenopus PPARγ. Using these cell lines, we were able to highlight major interspecies differences. Known hPPARγ pharmaceutical ligands modulated hPPARγ and mPPARγ activities in a similar manner, while xPPARγ was less responsive and zfPPARγ was not modulated at all by these compounds. On the contrary, human liver X receptor (hLXR) ligands GW 3965 and WAY-252623 were only active on zfPPARγ. Among environmental compounds, several molecules activated the PPARγ of the four species similarly, e.g., phthalates (MEHP), perfluorinated compounds (PFOA, PFOS), and halogenated derivatives of BPA (TBBPA, TCBPA), but some of them like diclofenac and the organophosphorus compounds tri-o-tolyl phosphate and triphenyl phosphate were most active on zfPPARγ. This study confirms or shows for the first time the h, m, x, and zfPPARγ activities of several chemicals and demonstrates the importance of the use of species-specific models to study endocrine and metabolism disruption by environmental chemicals.
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Affiliation(s)
- Clémentine Garoche
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université Montpellier, Institut régional du Cancer de Montpellier (ICM), 34290 Montpellier, France
| | - Abdelhay Boulahtouf
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université Montpellier, Institut régional du Cancer de Montpellier (ICM), 34290 Montpellier, France
| | - Marina Grimaldi
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université Montpellier, Institut régional du Cancer de Montpellier (ICM), 34290 Montpellier, France
| | - Barbara Chiavarina
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université Montpellier, Institut régional du Cancer de Montpellier (ICM), 34290 Montpellier, France
| | - Lucia Toporova
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université Montpellier, Institut régional du Cancer de Montpellier (ICM), 34290 Montpellier, France
| | - Marjo J den Broeder
- Institute for Risk Assessment Sciences, Department of Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Heidelberglaan 8, 3584 CS Utrecht, The Netherlands
| | - Juliette Legler
- Institute for Risk Assessment Sciences, Department of Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Heidelberglaan 8, 3584 CS Utrecht, The Netherlands
| | - William Bourguet
- Centre de Biologie Structurale (CBS), Inserm U1053, CNRS, Université Montpellier, 34290 Montpellier, France
| | - Patrick Balaguer
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université Montpellier, Institut régional du Cancer de Montpellier (ICM), 34290 Montpellier, France
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16
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Armitage JM, Sangion A, Parmar R, Looky AB, Arnot JA. Update and Evaluation of a High-Throughput In Vitro Mass Balance Distribution Model: IV-MBM EQP v2.0. TOXICS 2021; 9:toxics9110315. [PMID: 34822706 PMCID: PMC8625852 DOI: 10.3390/toxics9110315] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/15/2021] [Accepted: 11/17/2021] [Indexed: 11/16/2022]
Abstract
This study demonstrates the utility of an updated mass balance model for predicting the distribution of organic chemicals in in vitro test systems (IV-MBM EQP v2.0) and evaluates its performance with empirical data. The IV-MBM EQP v2.0 tool was parameterized and applied to four independent data sets with measured ratios of bulk medium or freely-dissolved to initial nominal concentrations (e.g., C24/C0 where C24 is the measured concentration after 24 h of exposure and C0 is the initial nominal concentration). Model performance varied depending on the data set, chemical properties (e.g., "volatiles" vs. "non-volatiles", neutral vs. ionizable organics), and model assumptions but overall is deemed acceptable. For example, the r2 was greater than 0.8 and the mean absolute error (MAE) in the predictions was less than a factor of two for most neutral organics included. Model performance was not as good for the ionizable organic chemicals included but the r2 was still greater than 0.7 and the MAE less than a factor of three. The IV-MBM EQP v2.0 model was subsequently applied to several hundred chemicals on Canada's Domestic Substances List (DSL) with nominal effects data (AC50s) reported for two in vitro assays. We report the frequency of chemicals with AC50s corresponding to predicted cell membrane concentrations in the baseline toxicity range (i.e., >20-60 mM) and tabulate the number of chemicals with "volatility issues" (majority of chemical in headspace) and "solubility issues" (freely-dissolved concentration greater than water solubility after distribution). In addition, the predicted "equivalent EQP blood concentrations" (i.e., blood concentration at equilibrium with predicted cellular concentration) were compared to the AC50s as a function of hydrophobicity (log octanol-water partition or distribution ratio). The predicted equivalent EQP blood concentrations exceed the AC50 by up to a factor of 100 depending on hydrophobicity and assay conditions. The implications of using AC50s as direct surrogates for human blood concentrations when estimating the oral equivalent doses using a toxicokinetic model (i.e., reverse dosimetry) are then briefly discussed.
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Affiliation(s)
- James M. Armitage
- AES Armitage Environmental Sciences, Inc., Ottawa, ON K1L 8C3, Canada
- Correspondence:
| | - Alessandro Sangion
- ARC Arnot Research and Consulting, Inc., Toronto, ON M4M 1W4, Canada; (A.S.); (R.P.); (A.B.L.); (J.A.A.)
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada
| | - Rohan Parmar
- ARC Arnot Research and Consulting, Inc., Toronto, ON M4M 1W4, Canada; (A.S.); (R.P.); (A.B.L.); (J.A.A.)
| | - Alexandra B. Looky
- ARC Arnot Research and Consulting, Inc., Toronto, ON M4M 1W4, Canada; (A.S.); (R.P.); (A.B.L.); (J.A.A.)
| | - Jon A. Arnot
- ARC Arnot Research and Consulting, Inc., Toronto, ON M4M 1W4, Canada; (A.S.); (R.P.); (A.B.L.); (J.A.A.)
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5S 1A8, Canada
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17
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Beil S, Markiewicz M, Pereira CS, Stepnowski P, Thöming J, Stolte S. Toward the Proactive Design of Sustainable Chemicals: Ionic Liquids as a Prime Example. Chem Rev 2021; 121:13132-13173. [PMID: 34523909 DOI: 10.1021/acs.chemrev.0c01265] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The tailorable and often unique properties of ionic liquids (ILs) drive their implementation into a broad variety of seminal technologies. The modular design of ILs allows in this context a proactive selection of structures that favor environmental sustainability─ideally without compromising their technological performance. To achieve this objective, the whole life cycle must be taken into account and various aspects considered simultaneously. In this review, we discuss how the structural design of ILs affects their environmental impacts throughout all stages of their life cycles and scrutinize the available data in order to point out knowledge gaps that need further research activities. The design of more sustainable ILs starts with the selection of the most beneficial precursors and synthesis routes, takes their technical properties and application specific performance into due account, and considers its environmental fate particularly in terms of their (eco)toxicity, biotic and abiotic degradability, mobility, and bioaccumulation potential. Special emphasis is placed on reported structure-activity relationships and suggested mechanisms on a molecular level that might rationalize the empirically found design criteria.
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Affiliation(s)
- Stephan Beil
- Institute of Water Chemistry, TU Dresden, 01062 Dresden, Germany
| | - Marta Markiewicz
- Institute of Water Chemistry, TU Dresden, 01062 Dresden, Germany
| | - Cristina Silva Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Av. da República, 2780-157 Oeiras, Portugal
| | - Piotr Stepnowski
- Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Jorg Thöming
- Chemical Process Engineering, University of Bremen, Leobener Straße 6, 28359 Bremen, Germany
| | - Stefan Stolte
- Institute of Water Chemistry, TU Dresden, 01062 Dresden, Germany
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18
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Lee J, Braun G, Henneberger L, König M, Schlichting R, Scholz S, Escher BI. Critical Membrane Concentration and Mass-Balance Model to Identify Baseline Cytotoxicity of Hydrophobic and Ionizable Organic Chemicals in Mammalian Cell Lines. Chem Res Toxicol 2021; 34:2100-2109. [PMID: 34357765 DOI: 10.1021/acs.chemrestox.1c00182] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
All chemicals can interfere with cellular membranes and this leads to baseline toxicity, which is the minimal toxicity any chemical elicits. The critical membrane burden is constant for all chemicals; that is, the dosing concentrations to trigger baseline toxicity decrease with increasing hydrophobicity of the chemicals. Quantitative structure-activity relationships, based on hydrophobicity of chemicals, have been established to predict nominal concentrations causing baseline toxicity in human and mammalian cell lines. However, their applicability is limited to hydrophilic neutral compounds. To develop a prediction model that includes more hydrophobic and charged organic chemicals, a mass balance model was applied for mammalian cells (AREc32, AhR-CALUX, PPARγ-BLA, and SH-SY5Y) considering different bioassay conditions. The critical membrane burden for baseline toxicity was converted into nominal concentration causing 10% cytotoxicity by baseline toxicity (IC10,baseline) using a mass balance model whose main chemical input parameter was the liposome-water partition constants (Klip/w) for neutral chemicals or the speciation-corrected Dlip/w(pH 7.4) for ionizable chemicals plus the bioassay-specific protein, lipid, and water contents of cells and media. In these bioassay-specific models, log(1/IC10,baseline) increased with increasing hydrophobicity, and the relationship started to level off at log Dlip/w around 2. The bioassay-specific models were applied to 392 chemicals covering a broad range of hydrophobicity and speciation. Comparing the predicted IC10,baseline and experimental cytotoxicity IC10, known baseline toxicants and many additional chemicals were identified as baseline toxicants, while the others were classified based on specificity of their modes of action in the four cell lines, confirming excess toxicity of some fungicides, antibiotics, and uncouplers. Given the similarity of the bioassay-specific models, we propose a generalized baseline-model for adherent human cell lines: log[1/IC10,baseline (M)] = 1.23 + 4.97 × (1 - e-0.236 log Dlip/w). The derived models for baseline toxicity may serve for specificity analysis in reporter gene and neurotoxicity assays as well as for planning the dosing for cell-based assays.
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Affiliation(s)
- Jungeun Lee
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, DE-04318 Leipzig, Germany
| | - Georg Braun
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, DE-04318 Leipzig, Germany
| | - Luise Henneberger
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, DE-04318 Leipzig, Germany
| | - Maria König
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, DE-04318 Leipzig, Germany
| | - Rita Schlichting
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, DE-04318 Leipzig, Germany
| | - Stefan Scholz
- Department of Bioanalytical Toxicology, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, DE-04318 Leipzig, Germany
| | - Beate I Escher
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, DE-04318 Leipzig, Germany.,Environmental Toxicology, Center for Applied Geoscience, Eberhard Karls University Tübingen, Scharrenbergstrasse 94-96, DE-72076 Tübingen, Germany
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19
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Baumer A, Jäsch S, Ulrich N, Bechmann I, Landmann J, Escher BI. Kinetics of Equilibrium Passive Sampling of Organic Chemicals with Polymers in Diverse Mammalian Tissues. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:9097-9108. [PMID: 34143604 DOI: 10.1021/acs.est.1c01836] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Equilibrium passive sampling employing polydimethylsiloxane (PDMS) as a sampling phase can be used for the extraction of complex mixtures of organic chemicals from lipid-rich biota. We extended the method to lean tissues and more hydrophilic chemicals by implementing a mass-balance model for partitioning between lipids, proteins, and water in tissues and by accelerating uptake kinetics with a custom-built stirrer that effectively decreased time to equilibrium to less than 8 days even for a homogenized liver tissue with an only 4% lipid content. The partition constants log Klipid/PDMS between tissues and PDMS were derived from measured concentration in PDMS and the mass-balance model and were very similar for 40 neutral chemicals with octanol-water partition constants 1.4 < log Kow < 8.7, that is, log Klipid/PDMS of 1.26 (95% CI, 1.13-1.39) for the adipose tissue, 1.16 (1.00-1.33) for the liver, and 0.58 (0.42-0.73) for the brain. This conversion factor can be applied to interpret chemical analysis and in vitro bioassays after additionally accounting for a small fraction of coextracted lipids of <0.7% of the PDMS weight. PDMS is more widely applicable for passive sampling of mammalian tissues than previously thought, both, in terms of diversity of chemicals and the range of lipid contents of tissues and, therefore, an ideal method for human biomonitoring to be combined with in vitro bioassays.
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Affiliation(s)
- Andreas Baumer
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research-UFZ, 04318 Leipzig, Germany
| | - Sandra Jäsch
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research-UFZ, 04318 Leipzig, Germany
| | - Nadin Ulrich
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research-UFZ, 04318 Leipzig, Germany
| | - Ingo Bechmann
- Institute of Anatomy, University of Leipzig, 04103 Leipzig, Germany
| | - Julia Landmann
- Institute of Anatomy, University of Leipzig, 04103 Leipzig, Germany
| | - Beate I Escher
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research-UFZ, 04318 Leipzig, Germany
- Environmental Toxicology, Centre for Applied Geosciences, Eberhard Karls University of Tübingen, 72076 Tübingen, Germany
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20
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Effective exposure of chemicals in in vitro cell systems: A review of chemical distribution models. Toxicol In Vitro 2021; 73:105133. [DOI: 10.1016/j.tiv.2021.105133] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 02/11/2021] [Accepted: 02/25/2021] [Indexed: 12/23/2022]
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21
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Krause S, Goss KU. Relevance of desorption kinetics and permeability for in vitro-based predictions of hepatic clearance in fish. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 235:105825. [PMID: 33857871 DOI: 10.1016/j.aquatox.2021.105825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/25/2021] [Accepted: 03/27/2021] [Indexed: 06/12/2023]
Abstract
The impact of desorption kinetics and permeation kinetics on in vitro-based predictions of in vivo hepatic blood clearances is investigated in the present study. Most commonly, possible limitations due to slow desorption of chemicals from albumin or slow permeation of chemicals through cellular membranes are not considered when in vivo clearances are predicted from in vitro biotransformation rate constants. To evaluate whether the most commonly used extrapolation models might thus overlook important kinetic limitations, we compare predictions of in vivo clearance that explicitly consider desorption and permeation kinetics with predictions of in vivo clearance that neglect these aspects. Our results show that strong limitations due to slow permeation kinetics are possible depending on the assumed permeability value. While permeability values estimated with a mechanistic approach are fast enough to avoid significant limitations, other experimentally derived permeability values lead to dramatically decreased in vivo clearance predictions. These latter values lead to unrealistically low in vivo biotransformation estimates. Furthermore, we also evaluated the implications of desorption kinetics using experimentally determined desorption rate constants. These evaluations show that slow desorption kinetics are unlikely to limit in vivo clearance.
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Affiliation(s)
- Sophia Krause
- Helmholtz Centre for Environmental Research, Department of Analytical Environmental Chemistry, Permoserstr. 15, 04318 Leipzig, Germany.
| | - Kai-Uwe Goss
- Helmholtz Centre for Environmental Research, Department of Analytical Environmental Chemistry, Permoserstr. 15, 04318 Leipzig, Germany; University of Halle-Wittenberg, Institute of Chemistry, Kurt-Mothes-Str. 2, 06120 Halle, Germany
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Predicting exposure concentrations of chemicals with a wide range of volatility and hydrophobicity in different multi-well plate set-ups. Sci Rep 2021; 11:4680. [PMID: 33633258 PMCID: PMC7907087 DOI: 10.1038/s41598-021-84109-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 02/03/2021] [Indexed: 11/16/2022] Open
Abstract
Quantification of chemical toxicity in small-scale bioassays is challenging owing to small volumes used and extensive analytical resource needs. Yet, relying on nominal concentrations for effect determination maybe erroneous because loss processes can significantly reduce the actual exposure. Mechanistic models for predicting exposure concentrations based on distribution coefficients exist but require further validation with experimental data. Here we developed a complementary empirical model framework to predict chemical medium concentrations using different well-plate formats (24/48-well), plate covers (plastic lid, or additionally aluminum foil or adhesive foil), exposure volumes, and biological entities (fish, algal cells), focusing on the chemicals’ volatility and hydrophobicity as determinants. The type of plate cover and medium volume were identified as important drivers of volatile chemical loss, which could accurately be predicted by the framework. The model focusing on adhesive foil as cover was exemplary cross-validated and extrapolated to other set-ups, specifically 6-well plates with fish cells and 24-well plates with zebrafish embryos. Two case study model applications further demonstrated the utility of the empirical model framework for toxicity predictions. Thus, our approach can significantly improve the applicability of small-scale systems by providing accurate chemical concentrations in exposure media without resource- and time-intensive analytical measurements.
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Henneberger L, Goss KU. Environmental Sorption Behavior of Ionic and Ionizable Organic Chemicals. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2021; 253:43-64. [PMID: 31748892 DOI: 10.1007/398_2019_37] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Traditionally our tools for environmental risk assessment of organic chemicals have been developed for neutral chemicals. However, many commercial chemicals are ionic or ionizable and require different tools and approaches for their assessment. In recent years this task starts to obtain increasing attention but our understanding for their environmental fate is still far behind that for neutral chemicals. This review first gives an overview on the principles that govern ionic partitioning in environmental systems which are more complex than the simple partition processes of neutral chemicals. Second, a summary of our current knowledge on various topics such as bioaccumulation, sorption in soils, and nonspecific-toxicity reveals that ionic species can actually be quite hydrophobic contrary to commonly held beliefs. Eventually, we discuss existing models for the quantitative prediction of organic ions' sorption in soils and biota. We have to assert that the available model tools are quite restricted in their application range compared to neutral chemicals which is due to the higher complexity of the various ionic sorption processes. In order to further advance our understanding more high-quality sorption data are needed with a focus on multivalent and zwitterionic ions in all partition systems as well as cations in biological matrices.
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Affiliation(s)
| | - Kai-Uwe Goss
- Helmholtz Centre for Environmental Research UFZ, Leipzig, Germany.
- Institute of Chemistry, University of Halle-Wittenberg, Halle, Germany.
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24
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Li X, Zhang C, Wang K, Lehmler HJ. Fatty liver and impaired hepatic metabolism alter the congener-specific distribution of polychlorinated biphenyls (PCBs) in mice with a liver-specific deletion of cytochrome P450 reductase. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 266:115233. [PMID: 32712482 PMCID: PMC7492420 DOI: 10.1016/j.envpol.2020.115233] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/22/2020] [Accepted: 07/10/2020] [Indexed: 05/09/2023]
Abstract
Polychlorinated biphenyls (PCBs) are persistent organic pollutants that are linked to adverse health outcomes. PCB tissue levels are determinants of PCB toxicity; however, it is unclear how factors, such as an altered metabolism and/or a fatty liver, affect PCB distribution in vivo. We determined the congener-specific disposition of PCBs in mice with a liver-specific deletion of cytochrome P450 reductase (KO), a model of fatty liver with impaired hepatic metabolism, and wild-type (WT) mice. Eight-week-old male WT (MWT, n = 3), male KO (MKO, n = 5), female WT (FWT, n = 4), and female KO mice (FKO, n = 4) were exposed orally to Aroclor 1254. PCBs were quantified in adipose, blood, brain, and liver tissues by gas chromatography-mass spectrometry. The ΣPCB levels followed the rank order adipose > liver ∼ brain > blood in WT and adipose ∼ liver > brain > blood in KO mice. PCB levels were much higher in the liver of KO than WT mice, irrespective of the sex. A comparison across exposure groups revealed minor genotype and sex-dependent differences in the PCB congener profiles (cos Θ > 0.92). Within each exposure group, tissue profiles showed small differences between tissues (cos Θ = 0.85 to 0.98). These differences were due to a decrease in metabolically more labile PCB congeners and an increase in congeners resistant to metabolism. The tissue-to-blood ratio of PCBs decreased for adipose, increased for the brain, and remained constant for the liver with an increase in chlorination. While these ratios did not follow the trends predicted using a composition-based model, the agreement between experimental and calculated partition coefficients was reasonable. Although the distribution of PCBs differs between KO and WT mice, the magnitude of the partitioning of PCBs from the blood into tissues can be approximated using composition-based models.
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Affiliation(s)
- Xueshu Li
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA
| | - Chunyun Zhang
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA
| | - Kai Wang
- Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA.
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25
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Maculewicz J, Świacka K, Kowalska D, Stepnowski P, Stolte S, Dołżonek J. In vitro methods for predicting the bioconcentration of xenobiotics in aquatic organisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 739:140261. [PMID: 32758962 DOI: 10.1016/j.scitotenv.2020.140261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/10/2020] [Accepted: 06/14/2020] [Indexed: 06/11/2023]
Abstract
The accumulation of anthropogenic chemical substances in aquatic organisms is an immensely important issue from the point of view of environmental protection. In the context of the increasing number and variety of compounds that may potentially enter the environment, there is a need for efficient and reliable solutions to assess the risks. However, the classic approach of testing with fish or other animals is not sufficient. Due to very high costs, significant time and labour intensity, as well as ethical concerns, in vivo methods need to be replaced by new laboratory-based tools. So far, many models have been developed to estimate the bioconcentration potential of chemicals. However, most of them are not sufficiently reliable and their predictions are based on limited input data, often obtained with doubtful quality. The octanol-water partition coefficient is still often used as the main laboratory tool for estimating bioconcentration. However, according to current knowledge, this method can lead to very unreliable results, both for neutral species and, above all, for ionic compounds. It is therefore essential to start using new, more advanced and credible solutions on a large scale. Over the last years, many in vitro methods have been newly developed or improved, allowing for a much more adequate estimation of the bioconcentration potential. Therefore, the aim of this work was to review the most recent laboratory methods for assessing the bioconcentration potential and to evaluate their applicability in further research.
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Affiliation(s)
- Jakub Maculewicz
- Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland.
| | - Klaudia Świacka
- Department of Experimental Ecology of Marine Organisms, Institute of Oceanography, University of Gdansk, Av. Pilsudskiego 46, 81-378 Gdynia, Poland
| | - Dorota Kowalska
- Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Piotr Stepnowski
- Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Stefan Stolte
- Faculty of Environmental Sciences, Department of Hydrosciences, Institute of Water Chemistry, Technische Universität Dresden, Bergstrasse 66, 01069 Dresden, Germany
| | - Joanna Dołżonek
- Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland
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26
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Chapman FM, Sparham C, Hastie C, Sanders DJ, van Egmond R, Chapman KE, Doak SH, Scott AD, Jenkins GJS. Comparison of passive-dosed and solvent spiked exposures of pro-carcinogen, benzo[a]pyrene, to human lymphoblastoid cell line, MCL-5. Toxicol In Vitro 2020; 67:104905. [PMID: 32497684 DOI: 10.1016/j.tiv.2020.104905] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 02/26/2020] [Accepted: 05/28/2020] [Indexed: 11/17/2022]
Abstract
Genotoxicity testing methods in vitro provide a means to predict the DNA damaging effects of chemicals on human cells. This is hindered in the case of hydrophobic test compounds, however, which will partition to in vitro components such as plastic-ware and medium proteins, in preference to the aqueous phase of the exposure medium. This affects the freely available test chemical concentration, and as this freely dissolved aqueous concentration is that bioavailable to cells, it is important to define and maintain this exposure. Passive dosing promises to have an advantage over traditional 'solvent spiking' exposure methods and involves the establishment and maintenance of known chemical concentrations in the in vitro medium, and therefore aqueous phase. Passive dosing was applied in a novel format to expose the MCL-5 human lymphoblastoid cell line to the pro-carcinogen, benzo[a]pyrene (B[a]P) and was compared to solvent (dimethyl sulphoxide) spiked B[a]P exposures over 48 h. Passive dosing induced greater changes, at lower concentrations, to micronucleus frequency, p21 mRNA expression, cell cycle abnormalities, and cell and nuclear morphology. This was attributed to a maintained, definable, free chemical concentration using passive dosing and the presence or absence of solvent, and highlights the influence of exposure choice on genotoxic outcomes.
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Affiliation(s)
- Fiona M Chapman
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Singleton Campus, Swansea SA2 8PP, UK.
| | - Chris Sparham
- Safety and Environmental Assurance Centre, Unilever, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - Colin Hastie
- Safety and Environmental Assurance Centre, Unilever, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - David J Sanders
- Safety and Environmental Assurance Centre, Unilever, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - Roger van Egmond
- Safety and Environmental Assurance Centre, Unilever, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - Katherine E Chapman
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Singleton Campus, Swansea SA2 8PP, UK
| | - Shareen H Doak
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Singleton Campus, Swansea SA2 8PP, UK
| | - Andrew D Scott
- Safety and Environmental Assurance Centre, Unilever, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - Gareth J S Jenkins
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Singleton Campus, Swansea SA2 8PP, UK
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27
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Ulrich N, Schweiger N, Pfennigsdorff A, Scholz S, Goss KU. Yolk-Water Partitioning of Neutral Organic Compounds in the Model Organism Danio rerio. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2020; 39:1506-1516. [PMID: 32383281 DOI: 10.1002/etc.4744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/14/2020] [Accepted: 05/03/2020] [Indexed: 06/11/2023]
Abstract
Yolk is the most important temporary biological compartment of the early life stages of fish embryos. The sorption strength of a chemical to yolk components may significantly influence the distribution of that chemical in the fish embryo. We determined yolk-water partition coefficients (Kyolk/water , in liters of water per kilogram of yolk, normalized to dry wt) for 70 neutral organic chemicals. The log Kyolk/water values range from 0.76 to 6.56. On the basis of these values, we developed polyparameter linear free energy relationship models to predict yolk-water partitioning for a broad range of neutral organic chemicals with a root mean squared error of 0.37 and r2 of 0.919. These models can be applied for the prediction of internal concentrations at equilibrium (neglecting biotransformation and active transport) in the zebrafish embryo test system. Environ Toxicol Chem 2020;39:1506-1516. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
- Nadin Ulrich
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Nicole Schweiger
- Department of Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Andrea Pfennigsdorff
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Stefan Scholz
- Department of Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Kai-Uwe Goss
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
- Institute of Chemistry, University of Halle-Wittenberg, Halle, Germany
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28
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Effinger A, M O'Driscoll C, McAllister M, Fotaki N. Gastrointestinal diseases and their impact on drug solubility: Ulcerative Colitis. Eur J Pharm Sci 2020; 152:105458. [PMID: 32645424 DOI: 10.1016/j.ejps.2020.105458] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/12/2020] [Accepted: 07/05/2020] [Indexed: 12/11/2022]
Abstract
For poorly soluble compounds, drug product performance in patients with Ulcerative Colitis (UC) compared to healthy subjects can be affected due to differences in drug solubility in GI fluids. A risk assessment tool was developed to identify compounds with a high risk of altered solubility in the GI fluids of UC patients. Pathophysiological changes impacting on the composition of GI fluids in UC patients were considered and UC biorelevant media representative of the stomach, intestine and colon were developed based on biorelevant media based on healthy subjects and literature data using a Design of Experiment approach. The UC media were characterised and revealed differences in surface tension, osmolality and buffer capacity compared to media based on healthy subjects. The solubility of six drugs was investigated in UC biorelevant media and results were related to media- and drug-dependent factors. A lower drug solubility in UC intestinal media was observed for compounds with a high lipophilicity. In UC simulated colonic fluids, drug solubility was altered for ionisable compounds. Additionally, a higher solubility of neutral lipophilic drugs was observed in UC fasted state colonic media with increased concentrations of soluble proteins. The developed UC biorelevant media offer the possibility to identify the risk of altered drug solubilisation in UC patients without conducting expensive clinical trials. A high risk was related to drug ionization properties and lipophilicity in the current study with all investigated drugs showing differences in solubility in biorelevant media based on UC patients compared to healthy subjects.
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Affiliation(s)
- Angela Effinger
- Department of Pharmacy and Pharmacology, University of Bath, Bath, UK
| | | | | | - Nikoletta Fotaki
- Department of Pharmacy and Pharmacology, University of Bath, Bath, UK.
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29
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Chen Y, Lei YD, Wensvoort J, Wania F. Quantifying the Biomagnification Capability of Arctic Wolf and Domestic Dog by Equilibrium Sampling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:6842-6849. [PMID: 32363860 DOI: 10.1021/acs.est.0c00157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The mechanism underlying contaminant biomagnification is a decrease in the volume (V) and the fugacity capacity (Z) of food during digestion in the gastrointestinal tract. Traditionally, biomagnification is quantified by measuring contaminant concentrations in animal tissues. Here, we present a proof-of-concept study to noninvasively derive the thermodynamic limit to an organism's biomagnification capability (biomagnification limit -BMFlim) by determining the ratio of the V·Z-products of undigested and digested food. We quantify Z-values by equilibrating food and feces samples, which have been homogenized and spiked with polychlorinated biphenyls (PCBs), with silicone films of variable thickness coated on the inside of glass vials. We demonstrate the feasibility of this method for wolf (Canis lupus hudsonicus) and domestic dog (Canis lupus familiaris). For an adult wolf eating a relatively lean meat diet, a BMFlim (averaged over several PCB congeners) of approximately 41 was observed, whereas the BMFlim reached 81 for an adult domestic dog eating a lipid-rich diet. Besides the dietary lipid content that strongly affects the Z-value of the diet, the capability of an animal to digest its diet also influences the BMFlim by controlling the Z-values of their feces and the volume reduction of the food in the gastrointestinal tract. Less efficient digestion leads to a lower BMFlim in a juvenile dog (approximately 35) compared to its older self, even though their diets had similar lipid contents. The effect of the volume reduction (VD/VF ranging from 4 to 15) was comparable to the effect of the Z-value reduction (ZD/ZF from 3 to 20).
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Affiliation(s)
- Yuhao Chen
- Department of Chemistry and Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4
| | - Ying Duan Lei
- Department of Chemistry and Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4
| | - Jaap Wensvoort
- Nutrition Science, Toronto Zoo, 361A Old Finch Avenue, Toronto, Ontario, Canada M1B 5K7
| | - Frank Wania
- Department of Chemistry and Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4
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30
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Henneberger L, Mühlenbrink M, Heinrich DJ, Teixeira A, Nicol B, Escher BI. Experimental Validation of Mass Balance Models for in Vitro Cell-Based Bioassays. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:1120-1127. [PMID: 31852189 DOI: 10.1021/acs.est.9b06144] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The freely dissolved concentration in the assay medium (Cfree) and the total cellular concentration (Ccell) are essential input parameters for quantitative in vitro-to-in vivo extrapolations (QIVIVE), but available prediction tools for Cfree and Ccell have not been sufficiently validated with experimental data. In this study, medium-water distribution ratios (DFBS/w) and cell-water distribution ratios (Dcell/w) for four different cells lines were determined experimentally for 12 neutral and five ionizable chemicals. Literature data for seven organic acids were added to the dataset, leading to 24 chemicals in total. A mass balance model based on bovine serum albumin-water (DBSA/w) and liposome-water distribution ratios (Dlip/w) of the chemicals was used to calculate DFBS/w and Dcell/w. For all neutral and basic test chemicals, the mass balance model predicted DFBS/w and Dcell/w within a factor of 3 and 3.4, respectively, indicating that existing models can reliably predict Cfree and Ccell for these chemicals. For organic acids, a further refinement of the model will be required as large deviations between modeled and measured binding to assay medium and cells of up to a factor of 370 were found. Furthermore, saturation of medium proteins should be further explored for organic acids and neutral chemicals with moderate hydrophobicity.
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Affiliation(s)
- Luise Henneberger
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research-UFZ , Permoserstr. 15 , 04318 Leipzig , Germany
| | - Marie Mühlenbrink
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research-UFZ , Permoserstr. 15 , 04318 Leipzig , Germany
| | - Daniel J Heinrich
- Environmental Toxicology, Center for Applied Geoscience , Eberhard Karls University Tübingen , 72074 Tübingen , Germany
| | - Alexandre Teixeira
- Safety & Environmental Assurance Centre , Colworth Science Park , Sharnbrook , Bedfordshire MK44 1LQ , U.K
| | - Beate Nicol
- Safety & Environmental Assurance Centre , Colworth Science Park , Sharnbrook , Bedfordshire MK44 1LQ , U.K
| | - Beate I Escher
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research-UFZ , Permoserstr. 15 , 04318 Leipzig , Germany
- Environmental Toxicology, Center for Applied Geoscience , Eberhard Karls University Tübingen , 72074 Tübingen , Germany
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31
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Birch H, Kramer NI, Mayer P. Time-Resolved Freely Dissolved Concentrations of Semivolatile and Hydrophobic Test Chemicals in In Vitro Assays-Measuring High Losses and Crossover by Headspace Solid-Phase Microextraction. Chem Res Toxicol 2019; 32:1780-1790. [PMID: 31426631 DOI: 10.1021/acs.chemrestox.9b00133] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In vitro assays are normally conducted in plastic multiwell plates open to exchange with the ambient air. The concentration of test substances freely available to cells is often not known, can change over time, and is difficult to measure in the small volumes in microplates. However, even a well-characterized toxicological response is of limited value if it cannot be linked to a well-defined exposure level. The aim of this study was to develop and apply an approach for determining time-resolved freely dissolved concentrations of semivolatile and hydrophobic organic chemicals (SVHOCs) in in vitro assays: (1) free fractions were measured by a new medium dilution method and (2) time-resolved loss curves were obtained by measurements of total concentrations in 96-well plates during incubations at 37 °C. Headspace solid-phase microextraction was used as an analytical technique for 24 model chemicals spanning 6 chemical groups and 4-5 orders of magnitude in Kow and Kaw. Free fractions were >30% for chemicals with log Kow < 3.5 and then decreased with increasing log Kow. Medium concentrations declined significantly (>50%) within 24 h of incubation for all 20 chemicals having log Kow > 4 or log Kaw > -3.5 in serum-free medium. Losses of chemicals were lower for medium containing 10% fetal bovine serum, most significantly for chemicals with log Kow > 4. High crossover to neighboring wells also was observed below log Kow of 4 and log Kaw of -3.5. Sealing the well plates had limited effect on the losses but clearly reduced crossover. The high losses and crossover of most tested chemicals question the suitability of multiwell plates for in vitro testing of SVHOCs and call for (1) test systems that minimize losses, (2) methods to control in vitro exposure, (3) analytical confirmation of exposure, and (4) exposure control and confirmation being included in good in vitro reporting standards.
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Affiliation(s)
- Heidi Birch
- Department of Environmental Engineering , Technical University of Denmark , Bygningstorvet, Building 115 , 2800 Kongens Lyngby , Denmark
| | - Nynke I Kramer
- Institute for Risk Assessment Sciences , Utrecht University , 3508 TC Utrecht , The Netherlands
| | - Philipp Mayer
- Department of Environmental Engineering , Technical University of Denmark , Bygningstorvet, Building 115 , 2800 Kongens Lyngby , Denmark
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32
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Escher BI, Glauch L, König M, Mayer P, Schlichting R. Baseline Toxicity and Volatility Cutoff in Reporter Gene Assays Used for High-Throughput Screening. Chem Res Toxicol 2019; 32:1646-1655. [PMID: 31313575 DOI: 10.1021/acs.chemrestox.9b00182] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Most studies using high-throughput in vitro cell-based bioassays tested chemicals up to a certain fixed concentration. It would be more appropriate to test up to concentrations predicted to elicit baseline toxicity because this is the minimal toxicity of every chemical. Baseline toxicity is also called narcosis and refers to nonspecific intercalation of chemicals in biological membranes, leading to loss of membrane structure and impaired functioning of membrane-related processes such as mitochondrial respiration. In cells, baseline toxicity manifests as cytotoxicity, which was quantified by a robust live-cell imaging method. Inhibitory concentrations for baseline toxicity varied by orders of magnitude between chemicals and were described by a simple quantitative structure activity relationship (QSAR) with the liposome-water partition constant as a sole descriptor. The QSAR equations were remarkably similar for eight reporter gene cell lines of different cellular origin, six of which were used in Tox21. Mass-balance models indicated constant critical membrane concentrations for all cells and all chemicals with a mean of 69 mmol·kglip-1(95% CI: 49-89), which is in the same range as for bacteria and aquatic organisms and consistent with the theory of critical membrane burden of narcosis. The challenge of developing baseline QSARs for cell lines is that many confirmed baseline toxicants are rather volatile. We deduced from cytotoxicity experiments with semi-volatile chemicals that only chemicals with medium-air partition constants >10,000 L/L can be tested in standard robotic setups without appreciable loss of effect. Chemicals just below that cutoff showed crossover effects in neighboring wells, whereas the effects of chemicals with lower medium-air partition constants were plainly lost. Applying the "volatility cut-off" to >8000 chemicals tested in Tox21 indicated that approximately 20% of Tox21 chemicals could have partially been lost during the experiments. We recommend applying the baseline QSARs together with volatility cut-offs for experimental planning of reporter gene assays, that is, to dose only chemicals with medium-air partition constants >10,000 at concentrations up to the baseline toxicity level.
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Affiliation(s)
- Beate I Escher
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research - UFZ , Permoserstr. 15 , DE-04318 Leipzig , Germany.,Environmental Toxicology, Center for Applied Geoscience , Eberhard Karls University Tübingen , Hölderlinstr. 12 , DE-72074 Tübingen , Germany
| | - Lisa Glauch
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research - UFZ , Permoserstr. 15 , DE-04318 Leipzig , Germany
| | - Maria König
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research - UFZ , Permoserstr. 15 , DE-04318 Leipzig , Germany
| | - Philipp Mayer
- Department of Environmental Engineering , Technical University of Denmark , Bygningstorvet 115 , DK-2800 Kongens Lyngby , Denmark
| | - Rita Schlichting
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research - UFZ , Permoserstr. 15 , DE-04318 Leipzig , Germany
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Fischer FC, Henneberger L, Schlichting R, Escher BI. How To Improve the Dosing of Chemicals in High-Throughput in Vitro Mammalian Cell Assays. Chem Res Toxicol 2019; 32:1462-1468. [DOI: 10.1021/acs.chemrestox.9b00167] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Fabian C. Fischer
- Department Cell Toxicology, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Luise Henneberger
- Department Cell Toxicology, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Rita Schlichting
- Department Cell Toxicology, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Beate I. Escher
- Department Cell Toxicology, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany
- Centre for Applied Geoscience, Eberhard Karls University Tübingen, 72074 Tübingen, Germany
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34
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Application of biomimetic HPLC to estimate in vivo behavior of early drug discovery compounds. FUTURE DRUG DISCOVERY 2019. [DOI: 10.4155/fdd-2019-0004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Characterizing the properties of large numbers of compounds and estimating their potential absorption, distribution, metabolism and elimination properties are important early stages in the process of drug discovery and help to reduce later stage attrition. The chromatographic separation principles using stationary phases that contain proteins and phospholipids are more suitable for compound characterization and estimation of the pharmacokinetic properties than the traditional octanol/water partition coefficient. This technology, when standardized, enables the prediction of in vivo behavior and the selection of compounds with the best potential, thus reducing the number of animal experiments. Chromatography may be involved more widely in the future to measure kinetic aspects of compounds’ binding to proteins and receptors which would enable designing compounds that require a lower frequency of doses and have more predictable pharmacokinetic profiles.
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35
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Henneberger L, Mühlenbrink M, König M, Schlichting R, Fischer FC, Escher BI. Quantification of freely dissolved effect concentrations in in vitro cell-based bioassays. Arch Toxicol 2019; 93:2295-2305. [DOI: 10.1007/s00204-019-02498-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 06/17/2019] [Indexed: 02/05/2023]
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36
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Groothuis FA, Timmer N, Opsahl E, Nicol B, Droge STJ, Blaauboer BJ, Kramer NI. Influence of in Vitro Assay Setup on the Apparent Cytotoxic Potency of Benzalkonium Chlorides. Chem Res Toxicol 2019; 32:1103-1114. [PMID: 31012305 PMCID: PMC6584903 DOI: 10.1021/acs.chemrestox.8b00412] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The nominal concentration
is generally used to express concentration–effect
relationships in in vitro toxicity assays. However, the nominal concentration
does not necessarily represent the exposure concentration responsible
for the observed effect. Surfactants accumulate at interphases and
likely sorb to in vitro system components such as serum protein and
well plate plastic. The extent of sorption and the consequences of
this sorption on in vitro readouts is largely unknown for these chemicals.
The aim of this study was to demonstrate the effect of sorption to
in vitro components on the observed cytotoxic potency of benzalkonium
chlorides (BAC) varying in alkyl chain length (6–18 carbon
atoms, C6–18) in a basal cytotoxicity assay with
the rainbow trout gill cell line (RTgill-W1). Cells were exposed for
48 h in 96-well plates to increasing concentration of BACs in exposure
medium containing 0, 60 μM bovine serum albumin (BSA) or 10%
fetal bovine serum (FBS). Before and after exposure, BAC concentrations
in exposure medium were analytically determined. Based on freely dissolved
concentrations at the end of the exposure, median effect concentrations
(EC50) decreased with increasing alkyl chain length up
to 14 carbons. For BAC with alkyl chains of 12 or more carbons, EC50’s based on measured concentrations after exposure
in supplement-free medium were up to 25-times lower than EC50’s calculated using nominal concentrations. When BSA or FBS
was added to the medium, a decrease in cytotoxic potency of up to
22 times was observed for BAC with alkyl chains of eight or more carbons.
The results of this study emphasize the importance of expressing the
in vitro readouts as a function of a dose metric that is least influenced
by assay setup to compare assay sensitivities and chemical potencies.
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Affiliation(s)
- Floris A Groothuis
- Institute for Risk Assessment Sciences , Utrecht University , PO Box 80177, 3508 TD Utrecht , The Netherlands
| | - Niels Timmer
- Institute for Risk Assessment Sciences , Utrecht University , PO Box 80177, 3508 TD Utrecht , The Netherlands
| | - Eystein Opsahl
- Institute for Risk Assessment Sciences , Utrecht University , PO Box 80177, 3508 TD Utrecht , The Netherlands
| | - Beate Nicol
- Safety & Environmental Assurance Centre , Unilever U.K. , Colworth Science Park, Sharnbrook, Bedford MK44 1LQ , United Kingdom
| | - Steven T J Droge
- Institute for Risk Assessment Sciences , Utrecht University , PO Box 80177, 3508 TD Utrecht , The Netherlands
| | - Bas J Blaauboer
- Institute for Risk Assessment Sciences , Utrecht University , PO Box 80177, 3508 TD Utrecht , The Netherlands
| | - Nynke I Kramer
- Institute for Risk Assessment Sciences , Utrecht University , PO Box 80177, 3508 TD Utrecht , The Netherlands
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37
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Zhang S, Wang Z, Chen J. Physiologically based toxicokinetics (PBTK) models for pharmaceuticals and personal care products in wild common carp (Cyprinus carpio). CHEMOSPHERE 2019; 220:793-801. [PMID: 30612048 DOI: 10.1016/j.chemosphere.2018.12.172] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 12/20/2018] [Accepted: 12/22/2018] [Indexed: 05/12/2023]
Abstract
Pharmaceutical and personal care products (PPCPs) are regarded as "pseudo-persistent" pollutants due to their being continuously loaded into the aquatic environment. Physiologically based toxicokinetics (PBTK) models that can quantitatively describe absorption, distribution, metabolism and excretion processes of chemicals in biota are of importance to predict internal exposure (e.g. doses at specific target tissues/organs) from external exposure concentrations. In this study, PBTK models with up to six compartments including brain, liver, kidney, gills, richly perfused tissues and poorly perfused tissues, were developed for predicting internal distribution of 10 PPCPs in wild common carp (Cyprinus carpio). The PBTK predicted concentrations were close to the measured ones, with deviations less than 1 log unit for most of PPCPs. Sensitivity analysis showed that various partition coefficients of the chemicals exerted significant influence on model outputs.
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Affiliation(s)
- Shuying Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, 116024, China
| | - Zhongyu Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, 116024, China
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, 116024, China.
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38
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Jiang R, Lin W, Zhang L, Zhu F, Ouyang G. Development of a novel solid phase microextraction calibration method for semi-solid tissue sampling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 655:174-180. [PMID: 30469063 DOI: 10.1016/j.scitotenv.2018.11.226] [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: 09/28/2018] [Revised: 11/14/2018] [Accepted: 11/15/2018] [Indexed: 06/09/2023]
Abstract
Accurate quantitative analysis using in vivo solid phase microextraction (SPME) for semi-solid tissue can be challenging due to the complexity of the sample matrix. In this paper, a comprehensive study was carried out on the extraction kinetics of SPME in the semi-solid sample, and subsequently proposed a new theoretical model to interpret the kinetic extraction process. Theoretically derived mathematical expressions well described the experimental desorption time profiles of the SPME process. Modelling experiments were also carried out to study the effect of sample tortuosity and binding matrix on the parameters affecting the extraction kinetics. Seven polyaromatic hydrocarbons (PAHs) and eight polychlorinated biphenyls (PCBs) in agarose gel and in real fish tissue were used for these experiments. The experimental data showed excellent agreement with theoretical prediction while providing excellent interpretation of the effect of tortuosity and binding matrix. Based on the theoretical model, an on-fiber standard calibration method with fewer internal standards was developed. The newly developed calibration method was used to quantify PAHs and PCBs in agarose gel and fish tissue. By using the proposed calibration method, a large number of organic compounds can be quantified with fewer internal standards. Current study provides the theoretical foundation for in vivo SPME quantitative semi-solid tissue analysis in the future.
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Affiliation(s)
- Ruifen Jiang
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China.
| | - Wei Lin
- KLGHEI of Environment and Energy Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
| | - Lifang Zhang
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Fang Zhu
- KLGHEI of Environment and Energy Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
| | - Gangfeng Ouyang
- KLGHEI of Environment and Energy Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
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39
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Lee H, Lee HJ, Kwon JH. Estimating microplastic-bound intake of hydrophobic organic chemicals by fish using measured desorption rates to artificial gut fluid. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 651:162-170. [PMID: 30227286 DOI: 10.1016/j.scitotenv.2018.09.068] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 09/05/2018] [Accepted: 09/05/2018] [Indexed: 06/08/2023]
Abstract
One of the most important concerns about marine microplastics is their role in delivery of chemical contaminants to biota. The contribution of microplastic ingestion to the overall uptake of five hydrophobic organic chemicals (HOCs) [α-, β-, and γ-hexachlorocyclohexanes (HCHs), pentachlorobenzene (PeCB), and hexachlorobenzene (HeCB)] by fish is evaluated in this study. Partition coefficients of all five HOCs between surfactant micelles and simulated intestinal fluid (SIF), as well as between protein and SIF, were experimentally determined. Desorption of model HOCs from a polyethylene film into an artificial gut solution was measured to estimate the fraction of HOCs that can be absorbed from microplastics during their gut retention time. Monte-Carlo simulation (n = 100,000) showed that the uptake via microplastic ingestion will be negligible for HCHs as compared to uptake via other exposure routes, water ventilation and food ingestion. On the other hand, microplastic ingestion might increase the total uptake rate of PeCB and HeCB due to their accelerated desorption from microplastics into the artificial gut solution under the model scenario, assuming an extremely high intake of microplastics. However, the steady-state bioaccumulation factor was predicted to decrease with increasing ingestion of microplastics, showing a dilution effect by microplastic ingestion. Results indicate that HOCs that are close to be at phase equilibrium between microplastics and environmental media are not likely to be further accumulated via ingestion of microplastics; this is true even for cases, where ingestion of microplastics contributes significantly to the total uptake of HOCs. Therefore, future studies need to focus on hydrophobic plastic additives that may exist in microplastics at a concentration higher than their equilibrium concentration with water.
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Affiliation(s)
- Hwang Lee
- Division of Environmental Science and Ecological Engineering, College of Life Sciences and Biotechnology, Korea University,Seoul 02841, Korea; Department of Marine Science and Research Institute of Basic Sciences, College of Natural Science, Incheon National University, Incheon 22012, Korea
| | - Hyun-Jeoung Lee
- Division of Environmental Science and Ecological Engineering, College of Life Sciences and Biotechnology, Korea University,Seoul 02841, Korea
| | - Jung-Hwan Kwon
- Division of Environmental Science and Ecological Engineering, College of Life Sciences and Biotechnology, Korea University,Seoul 02841, Korea.
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40
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Goss KU. The physical chemistry of odors - Consequences for the work with detection dogs. Forensic Sci Int 2019; 296:110-114. [PMID: 30711845 DOI: 10.1016/j.forsciint.2019.01.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 01/14/2019] [Indexed: 11/30/2022]
Abstract
Search dogs are used throughout the world in the search for illicit compounds or human individuals and similar tasks. Such search work is complex and not well understood in all its details which makes training of the dogs difficult. One important component for a successful education and deployment of search dogs is a good understanding of the behavior of scents under typical environmental conditions. This work summarizes up-to-date knowledge on the physico-chemistry of scents and discusses the consequences for the every-day work of dog handlers and trainers.
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Affiliation(s)
- Kai-Uwe Goss
- Helmholtz Centre for Environmental Research UFZ, Permoserstr. 15, D-04318, Leipzig, Germany; University of Halle-Wittenberg, Institute of Chemistry, Kurt-Mothes-Str. 2, D-06120, Halle, Germany.
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41
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Fisher C, Siméon S, Jamei M, Gardner I, Bois YF. VIVD: Virtual in vitro distribution model for the mechanistic prediction of intracellular concentrations of chemicals in in vitro toxicity assays. Toxicol In Vitro 2018; 58:42-50. [PMID: 30599189 DOI: 10.1016/j.tiv.2018.12.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/21/2018] [Accepted: 12/27/2018] [Indexed: 11/19/2022]
Abstract
In vitro toxicity testing routinely uses nominal treatment concentrations as the driver for measured toxicity endpoints. However, test compounds can bind to the plastic of culture vessels or interact with culture media components, such as lipids and albumin. Additionally, volatile compounds may partition into the air above culture media. These processes reduce the free concentrations of compound to which cells are exposed. Models predicting the freely dissolved concentrations by accounting for these interactions have been published. However, these have only been applied to neutral compounds or assume no differential ionisation of test compounds between the media and cell cytoplasm. Herein, we describe an in vitro distribution model, based on the Fick-Nernst Planck equation accounting for differential compound ionisation in culture medium and intracellular water. The model considers permeability of ionised and unionised species and accounts for membrane potential in the partitioning of ionised moieties. By accounting for lipid and protein binding in culture medium, binding to cell culture plastic, air-partitioning, and lipid binding in the cell, the model can predict chemical concentrations (free and total) in medium and cells. The model can improve in vitro in vivo extrapolation of toxicity endpoint by determining intracellular concentrations for translation to in vivo.
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Affiliation(s)
- C Fisher
- Certara UK Limited, Simcyp Division, Acero, 1 Concourse Way, Sheffield S1 2BJ, UK.
| | - S Siméon
- INERIS, METO Unit, Verneuil en Halatte, France
| | - M Jamei
- Certara UK Limited, Simcyp Division, Acero, 1 Concourse Way, Sheffield S1 2BJ, UK
| | - I Gardner
- Certara UK Limited, Simcyp Division, Acero, 1 Concourse Way, Sheffield S1 2BJ, UK
| | - Y F Bois
- INERIS, METO Unit, Verneuil en Halatte, France
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42
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Henneberger L, Mühlenbrink M, Fischer FC, Escher BI. C18-Coated Solid-Phase Microextraction Fibers for the Quantification of Partitioning of Organic Acids to Proteins, Lipids, and Cells. Chem Res Toxicol 2018; 32:168-178. [DOI: 10.1021/acs.chemrestox.8b00249] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Luise Henneberger
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research − UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Marie Mühlenbrink
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research − UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Fabian C. Fischer
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research − UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Beate I. Escher
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research − UFZ, Permoserstr. 15, 04318 Leipzig, Germany
- Environmental Toxicology, Center for Applied Geoscience, Eberhard Karls University Tübingen, 72074 Tübingen, Germany
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43
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Fischer FC, Cirpka OA, Goss KU, Henneberger L, Escher BI. Application of Experimental Polystyrene Partition Constants and Diffusion Coefficients to Predict the Sorption of Neutral Organic Chemicals to Multiwell Plates in in Vivo and in Vitro Bioassays. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:13511-13522. [PMID: 30298728 DOI: 10.1021/acs.est.8b04246] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Sorption to the polystyrene (PS) of multiwell plates can affect the exposure to organic chemicals over time in in vitro and in vivo bioassays. Experimentally determined diffusion coefficients in PS ( DPS) were in a narrow range of 1.25 to 8.0 · 10-16 m2 s-1 and PS-water partition constants ( KPS/w) ranged from 0.04 to 5.10 log-units for 22 neutral organic chemicals. A kinetic model, which explicitly accounts for diffusion in the plastic, was applied to predict the depletion of neutral organic chemicals from different bioassay media by sorption to various multiwell plate formats. For chemicals with log Kow > 3, the medium concentrations decreased rapidly and considerably in the fish embryo toxicity assay but medium concentrations remained relatively constant in the cell-based bioassays with medium containing 10% fetal bovine serum (FBS), emphasizing the ability of the protein- and lipid-rich medium to compensate for losses by multiwell plate sorption. The PS sorption data may serve not only for exposure assessment in bioassays but also to model the contaminant uptake by and release from plastic packaging material and the chemical transport by PS particles in the environment.
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Affiliation(s)
- Fabian C Fischer
- Helmholtz Centre for Environmental Research - UFZ , Department Cell Toxicology , Permoserstraße 15 , 04318 Leipzig , Germany
| | - Olaf A Cirpka
- Eberhard Karls University Tübingen , Center for Applied Geoscience , 72074 Tübingen , Germany
| | - Kai-Uwe Goss
- Helmholtz Centre for Environmental Research - UFZ , Department Analytical Environmental Chemistry , Permoserstraße 15 , 04318 Leipzig , Germany
| | - Luise Henneberger
- Helmholtz Centre for Environmental Research - UFZ , Department Cell Toxicology , Permoserstraße 15 , 04318 Leipzig , Germany
| | - Beate I Escher
- Helmholtz Centre for Environmental Research - UFZ , Department Cell Toxicology , Permoserstraße 15 , 04318 Leipzig , Germany
- Eberhard Karls University Tübingen , Center for Applied Geoscience , 72074 Tübingen , Germany
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44
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Lin H, Xia X, Jiang X, Bi S, Wang H, Zhai Y, Wen W, Guo X. Bioavailability of Pyrene Associated with Different Types of Protein Compounds: Direct Evidence for Its Uptake by Daphnia magna. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9851-9860. [PMID: 30102861 DOI: 10.1021/acs.est.8b03349] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The protein-like dissolved organic matter (DOM) is ubiquitous in aquatic environments. However, the bioavailability of protein-like DOM-associated hydrophobic organic compounds (HOCs) is not well-understood, and in particular, the direct evidence of their uptake by organisms is scarce. In the present work, tryptone (2000 Da), bovine serum albumin (BSA; 66 000 Da), and phycocyanin (120 000 Da) were chosen as model protein-like DOM, which were labeled by commercial fluorescein (cy5) to investigate the uptake mechanisms of protein compound-associated pyrene (a typical HOC) by Daphnia magna. The pyrene concentration in the tissues except the gut and immobilization of D. magna were detected to calculate the bioavailable fraction of protein compound-associated pyrene when the freely dissolved pyrene concentration was controlled through passive dosing devices. The results demonstrated that the tryptone could permeate cellular membrane and directly enter the tissues of D. magna from the exposure solutions, whereas BSA and phycocyanin might indirectly enter the tissues from the gut. A part of pyrene associated with protein compounds was bioavailable to D. magna; the order of their bioavailable fractions was trypone (54.6-58.1%) > phycocyanin (21.6-32.8%) > BSA (17.7-26.8%). The difference was principally related to the uptake mechanisms of pyrene associated with different types of protein. This work suggests that the protein compound-associated HOCs should be considered to evaluate the bioavailability and eco-environmental hazard of HOCs in natural waters.
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Affiliation(s)
- Hui Lin
- State Key Laboratory of Water Environment Simulation, School of Environment , Beijing Normal University , Beijing 100875 , China
| | - Xinghui Xia
- State Key Laboratory of Water Environment Simulation, School of Environment , Beijing Normal University , Beijing 100875 , China
| | - Xiaoman Jiang
- State Key Laboratory of Water Environment Simulation, School of Environment , Beijing Normal University , Beijing 100875 , China
| | - Siqi Bi
- State Key Laboratory of Water Environment Simulation, School of Environment , Beijing Normal University , Beijing 100875 , China
| | - Haotian Wang
- State Key Laboratory of Water Environment Simulation, School of Environment , Beijing Normal University , Beijing 100875 , China
| | - Yawei Zhai
- State Key Laboratory of Water Environment Simulation, School of Environment , Beijing Normal University , Beijing 100875 , China
| | - Wu Wen
- State Key Laboratory of Water Environment Simulation, School of Environment , Beijing Normal University , Beijing 100875 , China
| | - Xuejun Guo
- State Key Laboratory of Water Environment Simulation, School of Environment , Beijing Normal University , Beijing 100875 , China
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45
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Krause S, Goss KU. The impact of desorption kinetics from albumin on hepatic extraction efficiency and hepatic clearance: a model study. Arch Toxicol 2018; 92:2175-2182. [DOI: 10.1007/s00204-018-2224-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 05/17/2018] [Indexed: 01/10/2023]
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46
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Bittermann K, Linden L, Goss KU. Screening tools for the bioconcentration potential of monovalent organic ions in fish. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2018; 20:845-853. [PMID: 29714798 DOI: 10.1039/c8em00084k] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Currently the bioaccumulation potential of organic chemicals is assessed in a first tier approach via their octanol-water partition coefficient. This approach has been developed for neutral chemicals and cannot work for ionizable and ionic chemicals because the latter have different sorption-mechanisms and -preferences. Thus, suitable screening tools for the bioconcentration potential of ionic and ionizable chemicals need to be developed because it cannot be expected that these chemicals are non-bioaccumulative per se. Here, we present such screening tools for monovalent ions and ionizable chemicals based on calibrated sorption models for membrane lipids, structural proteins and albumin. The molecular descriptors used for these models arise from quantum chemical calculations and are based on COSMO-RS theory. When we applied our screening tools to 1839 preselected chemicals from the REACH registration data base, we identified 187 chemicals as potentially bioconcentrating (still ignoring any kind of metabolism). Among these were carbon and sulphur based aromatic and aliphatic acids mostly with a rather high molecular surface area. We hope that this outcome will trigger further research on ion specific sorption mechanisms and lead to a re-evaluation of the bioconcentration potential of ionic chemicals.
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Affiliation(s)
- Kai Bittermann
- Helmholtz Centre for Environmental Research UFZ, Department of Analytical Environmental Chemistry, Permoserstr. 15, D-04318 Leipzig, Germany.
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47
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Goss KU, Bittermann K, Henneberger L, Linden L. Equilibrium biopartitioning of organic anions - A case study for humans and fish. CHEMOSPHERE 2018; 199:174-181. [PMID: 29438944 DOI: 10.1016/j.chemosphere.2018.02.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 01/31/2018] [Accepted: 02/04/2018] [Indexed: 05/21/2023]
Abstract
In this work we combine partition coefficients between water and membrane lipid, storage lipid, the plasma protein albumin as well as structural protein with the tissue dependent fraction of the respective phases in order to obtain a clearer picture on the relevance of various biological tissues for the bioaccumulation of 31 organic anions. Most of the partition coefficients are based on experimental data, supplemented by some predicted ones. The data suggest that the plasma protein, albumin, will be the major sorption matrix in mammals. Only small fractions of the studied chemicals will occur freely dissolved in an organism. For the investigated acids with pKa <5, partitioning is dominated by the ionic species rather than the corresponding neutral species. Bioconcentration in fish is not expected to occur for many of these acids unless pH in the aqueous environment is low or specific sorption mechanisms are relevant. In contrast, biomagnification in terrestrial mammals would be expected for most organic anions if they are not sufficiently metabolized. We conclude that sorption is important for the toxicokinetics of ionizable organic chemicals and the dominating sorbing matrices are quite different from those for neutral species.
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Affiliation(s)
- Kai-Uwe Goss
- Helmholtz Centre for Environmental Research UFZ, Department of Analytical Environmental Chemistry, Permoserstr. 15, D-04318 Leipzig, Germany; University of Halle-Wittenberg, Institute of Chemistry, Kurt-Mothes-Str. 2, D-06120 Halle, Germany.
| | - Kai Bittermann
- Helmholtz Centre for Environmental Research UFZ, Department of Analytical Environmental Chemistry, Permoserstr. 15, D-04318 Leipzig, Germany
| | - Luise Henneberger
- Helmholtz Centre for Environmental Research UFZ, Department of Cell Toxicology, Permoserstr. 15, D-04318 Leipzig, Germany
| | - Lukas Linden
- Helmholtz Centre for Environmental Research UFZ, Department of Analytical Environmental Chemistry, Permoserstr. 15, D-04318 Leipzig, Germany
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48
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Zhao S, Jones KC, Sweetman AJ. Can poly-parameter linear-free energy relationships (pp-LFERs) improve modelling bioaccumulation in fish? CHEMOSPHERE 2018; 191:235-244. [PMID: 29035795 DOI: 10.1016/j.chemosphere.2017.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 09/30/2017] [Accepted: 10/01/2017] [Indexed: 06/07/2023]
Abstract
A wide range of studies have characterized different types of biosorbent, with regard to their interactions with chemicals. This has resulted in the development of poly-parameter linear free energy relationships (pp-LFERs) for the estimation of partitioning of neutral organic compounds to biological phases (e.g., storage lipids, phospholipids and serum albumins). The aims of this study were to explore and evaluate the influence of implementing pp-LFERs both into a one-compartment fish model and a multi-compartment physiologically based toxicokinetic (PBTK) fish model and the associated implications for chemical risk assessment. For this purpose, fish was used as reference biota, due to their important role in aquatic food chains and dietary exposure to humans. The bioconcentration factor (BCF) was utilized as the evaluation metric. Overall, our results indicated that models incorporating pp-LFERs (R2 = 0.75) slightly outperformed the single parameter (sp) LFERs approach in the one-compartmental fish model (R2 = 0.72). A pronounced enhancement was achieved for compounds with log KOW between 4 and 5 with increased R2 from 0.52 to 0.71. The minimal improvement was caused by the overestimation of lipid contribution and underestimation of protein contribution by the sp-approach, which cancelled each other out. Meanwhile, a greater improvement was observed for multi-compartmental PBTK models with consideration of metabolism, making all predictions fall within a factor of 10 compared with measured data. For screening purposes, the KOW-based (sp-LFERs) approach should be sufficient to quantify the main partitioning characteristics. Further developments are required for the consideration of ionization and more accurate quantification of biotransformation in biota.
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Affiliation(s)
- Shizhen Zhao
- Lancaster Environment Centre, Lancaster University, Lancaster, LA14YQ, UK; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Kevin C Jones
- Lancaster Environment Centre, Lancaster University, Lancaster, LA14YQ, UK
| | - Andrew J Sweetman
- Lancaster Environment Centre, Lancaster University, Lancaster, LA14YQ, UK.
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Desorption kinetics of organic chemicals from albumin. Arch Toxicol 2017; 92:1065-1074. [DOI: 10.1007/s00204-017-2117-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 11/08/2017] [Indexed: 10/18/2022]
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Pei Y, Li H, You J. Determining equilibrium partition coefficients between lipid/protein and polydimethylsiloxane for highly hydrophobic organic contaminants using preloaded disks. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 598:385-392. [PMID: 28448930 DOI: 10.1016/j.scitotenv.2017.04.123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 04/14/2017] [Accepted: 04/16/2017] [Indexed: 06/07/2023]
Abstract
Bioaccumulation of hydrophobic organic contaminants is of great concern and understanding their partitioning to biological phases is crucial for estimating their bioaccumulation potential. The estimation, however, was of large uncertainty for highly hydrophobic organic contaminants (HHOCs) with log KOW>9 due to the challenge of quantifying their water concentrations. In the present study, partition coefficients between polydimethylsiloxane (PDMS) and storage lipid (KSL,PDMS), membrane lipid (KML,PDMS) and protein (Kpro,PDMS) were measured for 21 polychlorinated biphenyls (PCBs), 14 polybrominated diphenyl ethers (PBDEs), dechlorane plus (DP) and decabromodiphenyl ethane (DBDPE), covering log KOW from 5.07 to 11.6, using a preloaded PDMS depletion method. The values of KSL,PDMS, KML,PDMS and Kpro,PDMS were in the ranges of 5.36-52.5, 0.286-11.8 and 0.067-2.62g/g, respectively, being relatively constant although their KOW values extend more than six orders of magnitude. The relative sorption capacity of the biological phases showed storage lipid was the dominant sorption phase in biota, followed by membrane lipid and protein was the lowest. The KPDMS,pro values of the compounds with log KOW<9 were similar (0.382-14.9g/g) regardless of the thickness of preloaded PDMS disks (58-209μm). For HHOCs, however, KPDMS,pro values dropped when thinner PDMS disks were used, as a result of slow diffusion of HHOCs in PDMS. The KPDMS,pro values of HHOCs measured by 58-μm PDMS disks ranged from 1.78 to 6.85g/g, which was consistent with compounds with log KOW<9. This validated that partition coefficients between PDMS and biological phases were independent of chemical hydrophobicity, showing the advantage of using PDMS-based methods to directly estimate bioaccumulation potential of HHOCs.
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Affiliation(s)
- Yuanyuan Pei
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huizhen Li
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China
| | - Jing You
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China.
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