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Ge J, Hou X, Liu L, Deng Q, Du B, Zeng L. Comprehensive Identification and Ubiquitous Occurrence of Eight Classes of Rubber-Derived Vulcanization Accelerators in Urban Dusts. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:5117-5128. [PMID: 38440993 DOI: 10.1021/acs.est.3c09920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2024]
Abstract
Vulcanization accelerators (VAs) serve as crucial additives in synthetic rubber on a global scale. Despite their widespread use, the environmental presence, distribution, and associated exposure risks of VAs remain poorly understood. This study compiled a target list and conducted a screening for eight classes encompassing 42 VAs in diverse urban dust samples from South China. A total of 40 of the 42 target VAs were detectable across all four studied regions, among which 30 were identified for the first time in the environment. Among the eight structure-classified VA classes, xanthates exhibited the highest concentrations (median: 3810-81,300 ng/g), followed by thiazoles, guanidines, sulfenamides, dithiocarbamates, thiurams, thioureas, and others. The median total concentrations of all target VAs (∑VAs) were determined to be 5060 ng/g in road dust, 5730 ng/g in parking lot dust, 29,200 ng/g in vehicle repair plant dust, and 84,300 ng/g in household dust, indicating the widespread presence of numerous rubber-derived VAs in various urban environments. This study marked the first systematic effort to identify a wide range of emerging rubber-derived VAs prevalent in urban environments. The findings call for increased attention to these widely utilized but less well-evaluated chemicals in future research and environmental management efforts.
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Affiliation(s)
- Jiali Ge
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China
| | - Xiangyu Hou
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China
| | - Li Liu
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China
| | - Qing Deng
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China
| | - Bibai Du
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China
| | - Lixi Zeng
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China
- School of Resources and Environmental Science, Quanzhou Normal University, Quanzhou 362000, China
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2
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Jurva U, Weidolf L, Sandinge AS, Leandersson C, Ekdahl A, Li XQ, Antonsson T, Sundell J, Westerlund K, Amilon C, Inghardt T, Gopaul VS. Biotransformation of the Novel Myeloperoxidase Inhibitor AZD4831 in Preclinical Species and Humans. Drug Metab Dispos 2023; 51:464-479. [PMID: 36653117 PMCID: PMC11022936 DOI: 10.1124/dmd.122.001099] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/17/2022] [Accepted: 12/15/2022] [Indexed: 01/19/2023] Open
Abstract
We report herein an in-depth analysis of the metabolism of the novel myeloperoxidase inhibitor AZD4831 ((R)-1-(2-(1-aminoethyl)-4-chlorobenzyl)-2-thioxo-2,3-dihydro-1H-pyrrolo[3,2-d]pyrimidin-4(5H)-one) in animals and human. Quantitative and qualitative metabolite profiling were performed on samples collected from mass balance studies in rats and humans. Exposure of circulating human metabolites with comparable levels in animal species used in safety assessment were also included. Structural characterization of 20 metabolites was performed by liquid chromatography high-resolution mass spectrometry, and quantification was performed by either 14C analysis using solid phase scintillation counting or accelerator mass spectrometry and, where available, authentication with synthesized metabolite standards. A complete mass balance study in rats is presented, while data from dogs and human are limited to metabolite profiling and characterization. The metabolism of AZD4831 is mainly comprised of reactions at the primary amine nitrogen and the thiourea sulfur, resulting in several conjugated metabolites with or without desulfurization. A carbamoyl glucuronide metabolite of AZD4831 (M7) was the most abundant plasma metabolite in both human healthy volunteers and heart failure patients after single and repeated dose administration of AZD4831, accounting for 75%-80% of the total drug-related exposure. Exposures to M7 and other human circulating metabolites were covered in rats and/or dogs, the two models most frequently used in the toxicology studies, and were also highly abundant in the mouse, the second model other than rat used in carcinogenicity studies. The carbamoyl glucuronide M7 was the main metabolite in rat bile, while a desulfurized and cyclized metabolite (M5) was abundant in rat plasma and excreta. SIGNIFICANCE STATEMENT: The biotransformation of AZD4831, a novel myeloperoxidase inhibitor inhibiting xanthine derivative bearing thiourea and primary aliphatic amine functions, is described. Twenty characterized metabolites demonstrate the involvement of carbamoylation with glucuronidation, desulfurization, and cyclization as main biotransformation reactions. The carbamoyl glucuronide was the main metabolite in human plasma, likely governed by a significant species difference in plasma protein binding for this metabolite, but this and other human plasma metabolites were covered in animals used in the toxicity studies.
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Affiliation(s)
- Ulrik Jurva
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (U.J., L.W., A-S.S., A.E., X.L., V.S.G.); Drug Metabolism and Pharmacokinetics, Research and Early Development, Respiratory and Immunology (C.L.), Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (T.A., J.S., K.W., T.I.), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and Formerly of AstraZeneca (L.W., C.A.)
| | - Lars Weidolf
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (U.J., L.W., A-S.S., A.E., X.L., V.S.G.); Drug Metabolism and Pharmacokinetics, Research and Early Development, Respiratory and Immunology (C.L.), Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (T.A., J.S., K.W., T.I.), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and Formerly of AstraZeneca (L.W., C.A.)
| | - Ann-Sofie Sandinge
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (U.J., L.W., A-S.S., A.E., X.L., V.S.G.); Drug Metabolism and Pharmacokinetics, Research and Early Development, Respiratory and Immunology (C.L.), Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (T.A., J.S., K.W., T.I.), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and Formerly of AstraZeneca (L.W., C.A.)
| | - Carina Leandersson
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (U.J., L.W., A-S.S., A.E., X.L., V.S.G.); Drug Metabolism and Pharmacokinetics, Research and Early Development, Respiratory and Immunology (C.L.), Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (T.A., J.S., K.W., T.I.), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and Formerly of AstraZeneca (L.W., C.A.)
| | - Anja Ekdahl
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (U.J., L.W., A-S.S., A.E., X.L., V.S.G.); Drug Metabolism and Pharmacokinetics, Research and Early Development, Respiratory and Immunology (C.L.), Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (T.A., J.S., K.W., T.I.), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and Formerly of AstraZeneca (L.W., C.A.)
| | - Xue-Qing Li
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (U.J., L.W., A-S.S., A.E., X.L., V.S.G.); Drug Metabolism and Pharmacokinetics, Research and Early Development, Respiratory and Immunology (C.L.), Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (T.A., J.S., K.W., T.I.), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and Formerly of AstraZeneca (L.W., C.A.)
| | - Thomas Antonsson
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (U.J., L.W., A-S.S., A.E., X.L., V.S.G.); Drug Metabolism and Pharmacokinetics, Research and Early Development, Respiratory and Immunology (C.L.), Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (T.A., J.S., K.W., T.I.), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and Formerly of AstraZeneca (L.W., C.A.)
| | - Johan Sundell
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (U.J., L.W., A-S.S., A.E., X.L., V.S.G.); Drug Metabolism and Pharmacokinetics, Research and Early Development, Respiratory and Immunology (C.L.), Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (T.A., J.S., K.W., T.I.), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and Formerly of AstraZeneca (L.W., C.A.)
| | - Kristina Westerlund
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (U.J., L.W., A-S.S., A.E., X.L., V.S.G.); Drug Metabolism and Pharmacokinetics, Research and Early Development, Respiratory and Immunology (C.L.), Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (T.A., J.S., K.W., T.I.), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and Formerly of AstraZeneca (L.W., C.A.)
| | - Carl Amilon
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (U.J., L.W., A-S.S., A.E., X.L., V.S.G.); Drug Metabolism and Pharmacokinetics, Research and Early Development, Respiratory and Immunology (C.L.), Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (T.A., J.S., K.W., T.I.), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and Formerly of AstraZeneca (L.W., C.A.)
| | - Tord Inghardt
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (U.J., L.W., A-S.S., A.E., X.L., V.S.G.); Drug Metabolism and Pharmacokinetics, Research and Early Development, Respiratory and Immunology (C.L.), Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (T.A., J.S., K.W., T.I.), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and Formerly of AstraZeneca (L.W., C.A.)
| | - V Sashi Gopaul
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (U.J., L.W., A-S.S., A.E., X.L., V.S.G.); Drug Metabolism and Pharmacokinetics, Research and Early Development, Respiratory and Immunology (C.L.), Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (T.A., J.S., K.W., T.I.), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and Formerly of AstraZeneca (L.W., C.A.)
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Voutchkova-Kostal A, Vaccaro S, Kostal J. Computer-Aided Discovery and Redesign for Respiratory Sensitization: A Tiered Mechanistic Model to Deliver Robust Performance Across a Diverse Chemical Space. Chem Res Toxicol 2022; 35:2097-2106. [PMID: 36190799 DOI: 10.1021/acs.chemrestox.2c00224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Asthma is among the most common occupational diseases with considerable public health and economic costs. Chemicals that induce hypersensitivity in the airways can cause respiratory distress and comorbidities with respiratory infections such as COVID. Robust predictive models for this end point are still elusive due to the lack of an experimental benchmark and the over-reliance of existing in silico tools on structural alerts and structural (vs chemical) similarities. The Computer-Aided Discovery and REdesign (CADRE) platform is a proven strategy for providing robust computational predictions for hazard end points using a tiered hybrid system of expert rules, molecular simulations, and quantum mechanics calculations. The recently developed CADRE model for respiratory sensitization is based on a highly curated data set of structurally diverse chemicals with high-fidelity biological data. The model evaluates absorption kinetics in lung mucosa using Monte Carlo simulations, assigns reactive centers in a molecule and possible biotransformations via expert rules, and determines subsequent reactivity with cell proteins via quantum-mechanics calculations using a multi-tiered regression. The model affords an accuracy above 0.90, with a series of external validations based on literature data in the range of 0.88-0.95. The model is applicable to all low-molecular-weight organics and can inform not only chemical substitution but also chemical redesign to advance development of safer alternatives.
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Affiliation(s)
- Adelina Voutchkova-Kostal
- Designing Out Toxicity (DOT) Consulting, LLC, 2121 Eisenhower Avenue, Alexandria, Virginia22314, United States.,The George Washington University, 800 22nd Street NW, Washington, DC20052, United States
| | - Samantha Vaccaro
- Designing Out Toxicity (DOT) Consulting, LLC, 2121 Eisenhower Avenue, Alexandria, Virginia22314, United States
| | - Jakub Kostal
- Designing Out Toxicity (DOT) Consulting, LLC, 2121 Eisenhower Avenue, Alexandria, Virginia22314, United States.,The George Washington University, 800 22nd Street NW, Washington, DC20052, United States
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Zhu X, Xu M, Sun J, Guo D, Zhang Y, Zhou S, Wang S. Hydroamination and Hydrophosphination of Isocyanates/Isothiocyanates under Catalyst‐Free Conditions. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100932] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Xiancui Zhu
- Key Laboratory of Functional Molecular Solids Ministry of Education Anhui Laboratory of Molecule-Based Materials College of Chemistry and Materials Science Anhui Normal University Wuhu Anhui 241002 China
| | - Mengchen Xu
- Key Laboratory of Functional Molecular Solids Ministry of Education Anhui Laboratory of Molecule-Based Materials College of Chemistry and Materials Science Anhui Normal University Wuhu Anhui 241002 China
| | - Jinrong Sun
- Key Laboratory of Functional Molecular Solids Ministry of Education Anhui Laboratory of Molecule-Based Materials College of Chemistry and Materials Science Anhui Normal University Wuhu Anhui 241002 China
| | - Dianjun Guo
- Key Laboratory of Functional Molecular Solids Ministry of Education Anhui Laboratory of Molecule-Based Materials College of Chemistry and Materials Science Anhui Normal University Wuhu Anhui 241002 China
| | - Yiwei Zhang
- Key Laboratory of Functional Molecular Solids Ministry of Education Anhui Laboratory of Molecule-Based Materials College of Chemistry and Materials Science Anhui Normal University Wuhu Anhui 241002 China
| | - Shuangliu Zhou
- Key Laboratory of Functional Molecular Solids Ministry of Education Anhui Laboratory of Molecule-Based Materials College of Chemistry and Materials Science Anhui Normal University Wuhu Anhui 241002 China
| | - Shaowu Wang
- Key Laboratory of Functional Molecular Solids Ministry of Education Anhui Laboratory of Molecule-Based Materials College of Chemistry and Materials Science Anhui Normal University Wuhu Anhui 241002 China
- Anhui Laboratory of Clean Catalytic Engineering Anhui Laboratory of Functional Complexes for Materials Chemistry and Application College of Chemical and Environmental Engineering Anhui Polytechnic University Wuhu Anhui 241002 China
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5
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Oesch F, Fabian E, Landsiedel R. Xenobiotica-metabolizing enzymes in the skin of rat, mouse, pig, guinea pig, man, and in human skin models. Arch Toxicol 2018; 92:2411-2456. [PMID: 29916051 PMCID: PMC6063329 DOI: 10.1007/s00204-018-2232-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 05/29/2018] [Indexed: 12/26/2022]
Abstract
Studies on the metabolic fate of medical drugs, skin care products, cosmetics and other chemicals intentionally or accidently applied to the human skin have become increasingly important in order to ascertain pharmacological effectiveness and to avoid toxicities. The use of freshly excised human skin for experimental investigations meets with ethical and practical limitations. Hence information on xenobiotic-metabolizing enzymes (XME) in the experimental systems available for pertinent studies compared with native human skin has become crucial. This review collects available information of which—taken with great caution because of the still very limited data—the most salient points are: in the skin of all animal species and skin-derived in vitro systems considered in this review cytochrome P450 (CYP)-dependent monooxygenase activities (largely responsible for initiating xenobiotica metabolism in the organ which provides most of the xenobiotica metabolism of the mammalian organism, the liver) are very low to undetectable. Quite likely other oxidative enzymes [e.g. flavin monooxygenase, COX (cooxidation by prostaglandin synthase)] will turn out to be much more important for the oxidative xenobiotic metabolism in the skin. Moreover, conjugating enzyme activities such as glutathione transferases and glucuronosyltransferases are much higher than the oxidative CYP activities. Since these conjugating enzymes are predominantly detoxifying, the skin appears to be predominantly protected against CYP-generated reactive metabolites. The following recommendations for the use of experimental animal species or human skin in vitro models may tentatively be derived from the information available to date: for dermal absorption and for skin irritation esterase activity is of special importance which in pig skin, some human cell lines and reconstructed skin models appears reasonably close to native human skin. With respect to genotoxicity and sensitization reactive-metabolite-reducing XME in primary human keratinocytes and several reconstructed human skin models appear reasonably close to human skin. For a more detailed delineation and discussion of the severe limitations see the Conclusions section in the end of this review.
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Affiliation(s)
- F Oesch
- Institute of Toxicology, Johannes Gutenberg-University, Obere Zahlbacherstr. 67, 55131, Mainz, Germany
| | - E Fabian
- Experimental Toxicology and Ecology, GV/TB, Z470, BASF SE, Carl-Bosch-Str. 38, 67056, Ludwigshafen, Germany
| | - Robert Landsiedel
- Experimental Toxicology and Ecology, GV/TB, Z470, BASF SE, Carl-Bosch-Str. 38, 67056, Ludwigshafen, Germany.
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Mescher M, Haarmann-Stemmann T. Modulation of CYP1A1 metabolism: From adverse health effects to chemoprevention and therapeutic options. Pharmacol Ther 2018; 187:71-87. [PMID: 29458109 DOI: 10.1016/j.pharmthera.2018.02.012] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The human cytochrome P450 (CYP) 1A1 gene encodes a monooxygenase that metabolizes multiple exogenous and endogenous substrates. CYP1A1 has become infamous for its oxidative metabolism of benzo[a]pyrene and related polycyclic aromatic hydrocarbons, converting these chemicals into very potent human carcinogens. CYP1A1 expression is mainly controlled by the aryl hydrocarbon receptor (AHR), a transcription factor whose activation is induced by binding of persistent organic pollutants, including polycyclic aromatic hydrocarbons and dioxins. Accordingly, induction of CYP1A1 expression and activity serves as a biomarker of AHR activation and associated xenobiotic metabolism as well as toxicity in diverse animal species and humans. Determination of CYP1A1 activity is integrated into modern toxicological concepts and testing guidelines, emphasizing the tremendous importance of this enzyme for risk assessment and regulation of chemicals. Further, CYP1A1 serves as a molecular target for chemoprevention of chemical carcinogenesis, although present literature is controversial on whether its inhibition or induction exerts beneficial effects. Regarding therapeutic applications, first anti-cancer prodrugs are available, which require a metabolic activation by CYP1A1, and thus enable a specific elimination of CYP1A1-positive tumors. However, the application range of these drugs may be limited due to the frequently observed downregulation of CYP1A1 in various human cancers, probably leading to a reduced metabolism of endogenous AHR ligands and a sustained activation of AHR and associated tumor-promoting responses. We here summarize the current knowledge on CYP1A1 as a key player in the metabolism of exogenous and endogenous substrates and as a promising target molecule for prevention and treatment of human malignancies.
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Affiliation(s)
- Melina Mescher
- IUF - Leibniz-Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
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Ramzy AG, Lammintausta K, Matura M, Bråred Christensson J, Nilsson U, Hagvall L. Isothiocyanates are important as haptens in contact allergy to chloroprene rubber. Br J Dermatol 2017; 177:522-530. [PMID: 28295200 DOI: 10.1111/bjd.15444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2017] [Indexed: 12/29/2022]
Abstract
BACKGROUND Contact allergy to chloroprene rubber products is well known. Thiourea compounds are considered the cause of allergy. Diethylthiourea commonly occurs in this type of product and can decompose to the sensitizer ethyl isothiocyanate. OBJECTIVES To investigate the clinical importance of degradation products and metabolites from organic thioureas in contact allergy to chloroprene rubber with a focus on isothiocyanates and isocyanates. METHODS Patients with contact allergy to diphenylthiourea were patch tested with phenyl isothiocyanate and phenyl isocyanate. Patients with known contact allergy to diethylthiourea were retested with diethylthiourea, while chemical analyses of their chloroprene rubber products were performed. The stability of diethylthiourea, diphenylthiourea and dibutylthiourea in patch-test preparations was investigated. Liquid chromatography/mass spectrometry and solid-phase microextraction/gas chromatography were used for determination of organic thioureas and isothiocyanates. RESULTS All patients allergic to diphenylthiourea reacted to phenyl isothiocyanate, two of eight reacted to phenyl isocyanate and six of eight reacted to diphenylthiourea. Four patients allergic to diethylthiourea reacted at retest; diethylthiourea was detected in all chloroprene rubber samples, with levels of 2-1200 nmol cm-2 . At 35 °C, ethyl isothiocyanate was emitted from all samples. Patch-test preparations of diethylthiourea, diphenylthiourea and dibutylthiourea all emitted the corresponding isothiocyanate, with diethylthiourea showing the highest rate of isothiocyanate emission. CONCLUSIONS Thiourea compounds are degraded to isothiocyanates, which are generally strong or extreme sensitizers, thus acting as prehaptens. This process occurs in both chloroprene rubber products and patch-test preparations. Positive reactions to phenyl isocyanate indicate cutaneous metabolism, as the only known source of exposure to phenyl isocyanate is through bioactivation of diphenylthiourea.
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Affiliation(s)
- A G Ramzy
- Department of Environmental Science and Analytical Chemistry, Stockholm University, Svante Arrhenius väg 16, Stockholm, SE-106 91, Sweden
| | - K Lammintausta
- Department of Dermatology, Turku University Hospital, Turku, 20521, Finland
| | - M Matura
- Centre for Occupational and Environmental Medicine, Stockholm County Council and Institute of Environmental Medicine, Karolinska Institutet, Stockholm, 171 77, Sweden
| | - J Bråred Christensson
- Department of Dermatology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, 413 45, Sweden.,Dermatochemistry, Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, 412 96, Sweden
| | - U Nilsson
- Department of Environmental Science and Analytical Chemistry, Stockholm University, Svante Arrhenius väg 16, Stockholm, SE-106 91, Sweden
| | - L Hagvall
- Department of Dermatology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, 413 45, Sweden
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Peptide Reactivity of Isothiocyanates--Implications for Skin Allergy. Sci Rep 2016; 6:21203. [PMID: 26883070 PMCID: PMC4756319 DOI: 10.1038/srep21203] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 01/15/2016] [Indexed: 11/29/2022] Open
Abstract
Skin allergy is a chronic condition that affects about 20% of the population of the western world. This disease is caused by small reactive compounds, haptens, able to penetrate into the epidermis and modify endogenous proteins, thereby triggering an immunogenic reaction. Phenyl isothiocyanate (PITC) and ethyl isothiocyanate (EITC) have been suggested to be responsible for allergic skin reactions to chloroprene rubber, the main constituent of wetsuits, orthopedic braces, and many types of sports gear. In the present work we have studied the reactivity of the isothiocyanates PITC, EITC, and tetramethylrhodamine-6-isothiocyanate (6-TRITC) toward peptides under aqueous conditions at physiological pH to gain information about the types of immunogenic complexes these compounds may form in the skin. We found that all three compounds reacted quickly with cysteine moieties. For PITC and 6-TRITC the cysteine adducts decomposed over time, while stable adducts with lysine were formed. These experimental findings were verified by DFT calculations. Our results may suggest that the latter are responsible for allergic reactions to isothiocyanates. The initial adduct formation with cysteine residues may still be of great importance as it prevents hydrolysis and facilitates the transport of isothiocyanates into epidermis where they can form stable immunogenic complexes with lysine-containing proteins.
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9
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Febriana S, Soebono H, Coenraads P, Schuttelaar M. Contact allergy in Indonesian patients with foot eczema attributed to shoes. J Eur Acad Dermatol Venereol 2015; 29:1582-9. [DOI: 10.1111/jdv.12951] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 12/04/2014] [Indexed: 11/29/2022]
Affiliation(s)
- S.A. Febriana
- Department of Dermatology & Venereology; Gadjah Mada University; Yogyakarta Indonesia
| | - H. Soebono
- Department of Dermatology & Venereology; Gadjah Mada University; Yogyakarta Indonesia
| | - P.J. Coenraads
- Department of Dermatology; University of Groningen; University Medical Center Groningen; Groningen The Netherlands
| | - M.L.A. Schuttelaar
- Department of Dermatology; University of Groningen; University Medical Center Groningen; Groningen The Netherlands
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10
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Ramzy AG, Hagvall L, Pei MN, Samuelsson K, Nilsson U. Investigation of diethylthiourea and ethyl isothiocyanate as potent skin allergens in chloroprene rubber. Contact Dermatitis 2014; 72:139-46. [PMID: 25532938 DOI: 10.1111/cod.12318] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/26/2014] [Accepted: 10/14/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Exposure to chloroprene rubber has resulted in numerous cases of allergic contact dermatitis, attributed to organic thiourea compounds used as vulcanization accelerators. However, thiourea compounds are not considered to be strong haptens. OBJECTIVES To analyse common commercial chloroprene materials for their contents of diethylthiourea (DETU), dibutylthiourea (DBTU), diphenylthiourea (DPTU), and their degradation products, isothiocyanates; and to investigate the sensitization potencies of possible degradation products of the mentioned thiourea compounds. METHODS Liquid chromatography/mass spectrometry (MS) was used for quantification of organic thiourea compounds in chloroprene products, such as medical, sports and diving gear; isothiocyanates were measured by solid-phase microextraction/gas chromatography/MS. Sensitization potencies were determined with the murine local lymph node assay (LLNA). RESULTS DETU was identified at concentrations of 2.7-9.4 µg/cm(2) in all samples, whereas neither DBTU nor DPTU was detected. At 37°C, degradation of DETU in the materials to ethyl isothiocyanate (EITC) was detected. EITC and ethyl isocyanate showed extreme and strong sensitization potencies, respectively, in the LLNA. CONCLUSIONS DETU can act as a prehapten, being degraded to EITC when subjected to body temperature upon skin contact. EITC could thus be the culprit behind allergic contact dermatitis caused by chloroprene rubber.
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Affiliation(s)
- Ahmad G Ramzy
- Department of Analytical Chemistry, Stockholm University, Svante Arrhenius väg 16, SE-106 91, Stockholm, Sweden
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Oesch F, Fabian E, Guth K, Landsiedel R. Xenobiotic-metabolizing enzymes in the skin of rat, mouse, pig, guinea pig, man, and in human skin models. Arch Toxicol 2014; 88:2135-90. [PMID: 25370008 PMCID: PMC4247477 DOI: 10.1007/s00204-014-1382-8] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 10/02/2014] [Indexed: 02/01/2023]
Abstract
The exposure of the skin to medical drugs, skin care products, cosmetics, and other chemicals renders information on xenobiotic-metabolizing enzymes (XME) in the skin highly interesting. Since the use of freshly excised human skin for experimental investigations meets with ethical and practical limitations, information on XME in models comes in the focus including non-human mammalian species and in vitro skin models. This review attempts to summarize the information available in the open scientific literature on XME in the skin of human, rat, mouse, guinea pig, and pig as well as human primary skin cells, human cell lines, and reconstructed human skin models. The most salient outcome is that much more research on cutaneous XME is needed for solid metabolism-dependent efficacy and safety predictions, and the cutaneous metabolism comparisons have to be viewed with caution. Keeping this fully in mind at least with respect to some cutaneous XME, some models may tentatively be considered to approximate reasonable closeness to human skin. For dermal absorption and for skin irritation among many contributing XME, esterase activity is of special importance, which in pig skin, some human cell lines, and reconstructed skin models appears reasonably close to human skin. With respect to genotoxicity and sensitization, activating XME are not yet judgeable, but reactive metabolite-reducing XME in primary human keratinocytes and several reconstructed human skin models appear reasonably close to human skin. For a more detailed delineation and discussion of the severe limitations see the “Overview and Conclusions” section in the end of this review.
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Affiliation(s)
- F Oesch
- Oesch-Tox Toxicological Consulting and Expert Opinions GmbH&Co.KG, Rheinblick 21, 55263, Wackernheim, Germany
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Dahlin J, Bergendorff O, Vindenes HK, Hindsén M, Svedman C. Triphenylguanidine, a new (old?) rubber accelerator detected in surgical gloves that may cause allergic contact dermatitis. Contact Dermatitis 2014; 71:242-6. [DOI: 10.1111/cod.12276] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/16/2014] [Accepted: 05/20/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Jakob Dahlin
- Department of Occupational and Environmental Dermatology; Skåne University Hospital, Lund University; S-205 02 Malmö Sweden
| | - Ola Bergendorff
- Department of Dermatology; Skåne University Hospital; S-221 85 Lund Sweden
| | - Hilde K. Vindenes
- Department of Dermatology; Haukeland Unversity Hospital; 5021 Bergen Norway
| | - Monica Hindsén
- Department of Occupational and Environmental Dermatology; Skåne University Hospital, Lund University; S-205 02 Malmö Sweden
| | - Cecilia Svedman
- Department of Occupational and Environmental Dermatology; Skåne University Hospital, Lund University; S-205 02 Malmö Sweden
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13
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Alépée N, Bahinski A, Daneshian M, De Wever B, Fritsche E, Goldberg A, Hansmann J, Hartung T, Haycock J, Hogberg H, Hoelting L, Kelm JM, Kadereit S, McVey E, Landsiedel R, Leist M, Lübberstedt M, Noor F, Pellevoisin C, Petersohn D, Pfannenbecker U, Reisinger K, Ramirez T, Rothen-Rutishauser B, Schäfer-Korting M, Zeilinger K, Zurich MG. State-of-the-art of 3D cultures (organs-on-a-chip) in safety testing and pathophysiology. ALTEX-ALTERNATIVES TO ANIMAL EXPERIMENTATION 2014. [PMID: 25027500 DOI: 10.14573/altex1406111] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Integrated approaches using different in vitro methods in combination with bioinformatics can (i) increase the success rate and speed of drug development; (ii) improve the accuracy of toxicological risk assessment; and (iii) increase our understanding of disease. Three-dimensional (3D) cell culture models are important building blocks of this strategy which has emerged during the last years. The majority of these models are organotypic, i.e., they aim to reproduce major functions of an organ or organ system. This implies in many cases that more than one cell type forms the 3D structure, and often matrix elements play an important role. This review summarizes the state of the art concerning commonalities of the different models. For instance, the theory of mass transport/metabolite exchange in 3D systems and the special analytical requirements for test endpoints in organotypic cultures are discussed in detail. In the next part, 3D model systems for selected organs--liver, lung, skin, brain--are presented and characterized in dedicated chapters. Also, 3D approaches to the modeling of tumors are presented and discussed. All chapters give a historical background, illustrate the large variety of approaches, and highlight up- and downsides as well as specific requirements. Moreover, they refer to the application in disease modeling, drug discovery and safety assessment. Finally, consensus recommendations indicate a roadmap for the successful implementation of 3D models in routine screening. It is expected that the use of such models will accelerate progress by reducing error rates and wrong predictions from compound testing.
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Alépée N, Bahinski A, Daneshian M, De Wever B, Fritsche E, Goldberg A, Hansmann J, Hartung T, Haycock J, Hogberg HT, Hoelting L, Kelm JM, Kadereit S, McVey E, Landsiedel R, Leist M, Lübberstedt M, Noor F, Pellevoisin C, Petersohn D, Pfannenbecker U, Reisinger K, Ramirez T, Rothen-Rutishauser B, Schäfer-Korting M, Zeilinger K, Zurich MG. State-of-the-art of 3D cultures (organs-on-a-chip) in safety testing and pathophysiology. ALTEX 2014; 31:441-77. [PMID: 25027500 PMCID: PMC4783151 DOI: 10.14573/altex.1406111] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 06/30/2014] [Indexed: 02/02/2023]
Abstract
Integrated approaches using different in vitro methods in combination with bioinformatics can (i) increase the success rate and speed of drug development; (ii) improve the accuracy of toxicological risk assessment; and (iii) increase our understanding of disease. Three-dimensional (3D) cell culture models are important building blocks of this strategy which has emerged during the last years. The majority of these models are organotypic, i.e., they aim to reproduce major functions of an organ or organ system. This implies in many cases that more than one cell type forms the 3D structure, and often matrix elements play an important role. This review summarizes the state of the art concerning commonalities of the different models. For instance, the theory of mass transport/metabolite exchange in 3D systems and the special analytical requirements for test endpoints in organotypic cultures are discussed in detail. In the next part, 3D model systems for selected organs--liver, lung, skin, brain--are presented and characterized in dedicated chapters. Also, 3D approaches to the modeling of tumors are presented and discussed. All chapters give a historical background, illustrate the large variety of approaches, and highlight up- and downsides as well as specific requirements. Moreover, they refer to the application in disease modeling, drug discovery and safety assessment. Finally, consensus recommendations indicate a roadmap for the successful implementation of 3D models in routine screening. It is expected that the use of such models will accelerate progress by reducing error rates and wrong predictions from compound testing.
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Affiliation(s)
| | - Anthony Bahinski
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, USA
| | - Mardas Daneshian
- Center for Alternatives to Animal Testing – Europe (CAAT-Europe), University of Konstanz, Konstanz, Germany
| | | | - Ellen Fritsche
- Leibniz Research Institute for Environmental Medicine, Duesseldorf, Germany
| | - Alan Goldberg
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Bloomberg School of Public Health, Baltimore, USA
| | - Jan Hansmann
- Department of Tissue Engineering and Regenerative Medicine, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Thomas Hartung
- Center for Alternatives to Animal Testing – Europe (CAAT-Europe), University of Konstanz, Konstanz, Germany,Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Bloomberg School of Public Health, Baltimore, USA
| | - John Haycock
- Department of Materials Science of Engineering, University of Sheffield, Sheffield, UK
| | - Helena T. Hogberg
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Bloomberg School of Public Health, Baltimore, USA
| | - Lisa Hoelting
- Doerenkamp-Zbinden Chair of in vitro Toxicology and Biomedicine, University of Konstanz, Konstanz, Germany
| | | | - Suzanne Kadereit
- Doerenkamp-Zbinden Chair of in vitro Toxicology and Biomedicine, University of Konstanz, Konstanz, Germany
| | - Emily McVey
- Board for the Authorization of Plant Protection Products and Biocides, Wageningen, The Netherlands
| | | | - Marcel Leist
- Center for Alternatives to Animal Testing – Europe (CAAT-Europe), University of Konstanz, Konstanz, Germany,Doerenkamp-Zbinden Chair of in vitro Toxicology and Biomedicine, University of Konstanz, Konstanz, Germany
| | - Marc Lübberstedt
- Bioreactor Group, Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité Campus Virchow-Klinikum, Berlin, Germany
| | - Fozia Noor
- Biochemical Engineering, Saarland University, Saarbruecken, Germany
| | | | | | | | | | - Tzutzuy Ramirez
- BASF SE, Experimental Toxicology and Ecology, Ludwigshafen, Germany
| | | | - Monika Schäfer-Korting
- Institute for Pharmacy (Pharmacology and Toxicology), Freie Universität Berlin, Berlin, Germany
| | - Katrin Zeilinger
- Bioreactor Group, Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité Campus Virchow-Klinikum, Berlin, Germany
| | - Marie-Gabriele Zurich
- Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland,Swiss Center for Applied Human Toxicology (SCAHT), University of Lausanne, Lausanne, Switzerland
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Payne MP, Button WG. Prediction of acute aquatic toxicity in Tetrahymena pyriformis--'Eco-Derek', a knowledge-based system approach. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2013; 24:439-460. [PMID: 23600431 DOI: 10.1080/1062936x.2013.783507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A 'proof-of-concept' version of a software tool for making transparent predictions of acute aquatic toxicity has been developed. It is primarily limited to semi-quantitative predictions in one species, the ciliated protozoan, Tetrahymena pyriformis. A freely available system, 'Eco-Derek', was derived by adapting a well-established, knowledge-based structure-activity and reasoning platform (Derek for Windows, Lhasa Limited). The Derek reasoning code was modified to express potency rather than confidence. Structure-activity relationship (SAR) development utilised a curated version of a published dataset, supplemented with the CADASTER Challenge datasets. Forty-five structural alerts were produced. The dependence on log P was examined for each alert and entered into the system as qualitative reasoning rules specifying the predicted potency as Very Low, Low, Moderate, High or Very High. Evaluation studies showed: (a) moderate accuracy for the training set but low accuracy for an external test set; (b) non-linearity in the toxicity-log P relationship for chemicals without identified structural alerts; (c) insufficient differentiation of substituent effects in some of the reactivity-based structural alerts resulting in too few chemicals predicted with Very High toxicity; and (d) the need for additional structural alerts covering polar narcosis and less common reactive or metabolically activated chemical functionality.
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Guldbrand S, Kirejev V, Simonsson C, Goksör M, Smedh M, Ericson MB. Two-photon fluorescence correlation spectroscopy as a tool for measuring molecular diffusion within human skin. Eur J Pharm Biopharm 2012; 84:430-6. [PMID: 23085333 DOI: 10.1016/j.ejpb.2012.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Revised: 09/25/2012] [Accepted: 10/01/2012] [Indexed: 01/19/2023]
Abstract
There is a need for tools enabling quantitative imaging of biological tissue for pharmaceutical applications. In this study, two-photon fluorescence microscopy (TPM) has been combined with fluorescence correlation spectroscopy (FCS), demonstrating proof-of-principle providing quantitative data of fluorophore concentration and diffusion in human skin. Measurements were performed on excised skin exposed to either rhodamine B (RB) or rhodamine B isothiocyanate (RBITC), chosen based on their similarity in fluorescence yield and molecular weight, but difference in chemical reactivity. The measurements were performed at tissue depths in the range 0 and 20 μm, and the diffusion coefficients at skin depths 5 and 10 μm were found to be significantly different (P<0.05). Overall median values for the diffusion coefficients were found to be 4.0×10(-13) m(2)/s and 2.0×10(-13) m(2)/s for RB and RBITC, respectively. These values correspond to the diffusion of a hard sphere with a volume eight times larger for RBITC compared to RB. This indicates that the RBITC have bound to biomolecules in the skin, and the measured signal is obtained from the RBITC-biomolecule complexes, demonstrating the potential of the TPM-FCS method to track molecular interactions in an intricate biological matrix such as human skin.
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Affiliation(s)
- Stina Guldbrand
- Department of Physics, University of Gothenburg, Gothenburg, Sweden.
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Simonsson C, Stenfeldt AL, Karlberg AT, Ericson MB, Jonsson CA. The pilosebaceous unit—a phthalate-induced pathway to skin sensitization. Toxicol Appl Pharmacol 2012; 264:114-20. [DOI: 10.1016/j.taap.2012.07.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 06/20/2012] [Accepted: 07/19/2012] [Indexed: 11/25/2022]
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Geier J, Lessmann H, Mahler V, Pohrt U, Uter W, Schnuch A. Occupational contact allergy caused by rubber gloves - nothing has changed. Contact Dermatitis 2012; 67:149-56. [DOI: 10.1111/j.1600-0536.2012.02139.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Sarma D, Hajovsky H, Koen YM, Galeva NA, Williams TD, Staudinger JL, Hanzlik RP. Covalent modification of lipids and proteins in rat hepatocytes and in vitro by thioacetamide metabolites. Chem Res Toxicol 2012; 25:1868-77. [PMID: 22667464 DOI: 10.1021/tx3001658] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Thioacetamide (TA) is a well-known hepatotoxin in rats. Acute doses cause centrilobular necrosis and hyperbilirubinemia while chronic administration leads to biliary hyperplasia and cholangiocarcinoma. Its acute toxicity requires its oxidation to a stable S-oxide (TASO) that is oxidized further to a highly reactive S,S-dioxide (TASO(2)). To explore possible parallels among the metabolism, covalent binding, and toxicity of TA and thiobenzamide (TB), we exposed freshly isolated rat hepatocytes to [(14)C]-TASO or [(13)C(2)D(3)]-TASO. TLC analysis of the cellular lipids showed a single major spot of radioactivity that mass spectral analysis showed to consist of N-acetimidoyl PE lipids having the same side chain composition as the PE fraction from untreated cells; no carbons or hydrogens from TASO were incorporated into the fatty acyl chains. Many cellular proteins contained N-acetyl- or N-acetimidoyl lysine residues in a 3:1 ratio (details to be reported separately). We also oxidized TASO with hydrogen peroxide in the presence of dipalmitoyl phosphatidylenthanolamine (DPPE) or lysozyme. Lysozyme was covalently modified at five of its six lysine side chains; only acetamide-type adducts were formed. DPPE in liposomes also gave only amide-type adducts, even when the reaction was carried out in tetrahydrofuran with only 10% water added. The exclusive formation of N-acetimidoyl PE in hepatocytes means that the concentration or activity of water must be extremely low in the region where TASO(2) is formed, whereas at least some of the TASO(2) can hydrolyze to acetylsulfinic acid before it reacts with cellular proteins. The requirement for two sequential oxidations to produce a reactive metabolite is unusual, but it is even more unusual that a reactive metabolite would react with water to form a new compound that retains a high degree of chemical reactivity toward biological nucleophiles. The possible contribution of lipid modification to the hepatotoxicity of TA/TASO remains to be determined.
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Affiliation(s)
- Diganta Sarma
- Department of Medicinal Chemistry, The University of Kansas, Lawrence, KA 66045, USA
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20
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Schebb NH, Buchholz BA, Hammock BD, Rice RH. Metabolism of the antibacterial triclocarban by human epidermal keratinocytes to yield protein adducts. J Biochem Mol Toxicol 2012; 26:230-4. [PMID: 22711420 PMCID: PMC3522462 DOI: 10.1002/jbt.21411] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Previous studies of triclocarban suggest that its biotransformation could yield reactive metabolites that form protein adducts. Since the skin is the major route of triclocarban exposure, present work examined this possibility in cultured human keratinocytes. The results provide evidence for considerable biotransformation and protein adduct formation when cytochrome P450 activity is induced in the cells by 2,3,7,8-tetrachlorodibenzo-p-dioxin, a model Ah receptor ligand. Since detecting low adduct levels in cells and tissues is difficult, we utilized the novel approach of accelerator mass spectrometry for this purpose. Exploiting the sensitivity of the method, we demonstrated that a substantial portion of triclocarban forms adducts with keratinocyte protein under the P450 inducing conditions employed.
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Affiliation(s)
- Nils Helge Schebb
- Institute of Food Toxicology and Chemical Analysis, University of Veterinary Medicine Hannover, Germany
| | - Bruce A. Buchholz
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - Bruce D. Hammock
- Department of Entomology and Cancer Center, University of California, Davis, CA
| | - Robert H. Rice
- Department of Environmental Toxicology, University of California, Davis, CA
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Jäckh C, Fabian E, van Ravenzwaay B, Landsiedel R. Relevance of xenobiotic enzymes in human skin in vitro models to activate pro-sensitizers. J Immunotoxicol 2012; 9:426-38. [PMID: 22471730 DOI: 10.3109/1547691x.2012.664578] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Skin exposure to sensitizing chemicals can induce allergic reactions. Certain chemicals, so called pro-sensitizers, need metabolic activation to become allergenic. Their metabolic activation occurs in skin cells such as keratinocytes or dendritic cells. These cell types are also incorporated into dermal in vitro test systems used to assess the sensitizing potential of chemicals for humans. In vitrosystems range from single cell cultures to organotypic multi-cellular reconstructed skin models. Until now, their metabolic competence to unmask sensitizing potential of pro-sensitizers was rarely investigated. This review aims to summarize current information on available skin in vitro models and the relevance of xenobiotic metabolizing enzymes for the activation of pro-sensitizers such as eugenol, 4-allylanisole, and ethylendiamine. Among others, these chemicals are discussed as performance standards to validate new coming in vitro systems for their potential to identify pro-sensitizers.
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Affiliation(s)
- Christine Jäckh
- BASF SE, Experimental Toxicology and Ecology, 67056 Ludwigshafen, Germany
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22
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Current world literature. Curr Opin Allergy Clin Immunol 2011; 11:497-502. [PMID: 21878753 DOI: 10.1097/aci.0b013e32834bbdcd] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Haptenation: chemical reactivity and protein binding. J Allergy (Cairo) 2011; 2011:839682. [PMID: 21785613 PMCID: PMC3138048 DOI: 10.1155/2011/839682] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 04/27/2011] [Indexed: 11/23/2022] Open
Abstract
Low molecular weight chemical (LMW) allergens are commonly referred to as haptens. Haptens must complex with proteins to be recognized by the immune system. The majority of occupationally related haptens are reactive, electrophilic chemicals, or are metabolized to reactive metabolites that form covalent bonds with nucleophilic centers on proteins. Nonelectrophilic protein binding may occur through disulfide exchange, coordinate covalent binding onto metal ions on metalloproteins or of metal allergens, themselves, to the major histocompatibility complex. Recent chemical reactivity kinetic studies suggest that the rate of protein binding is a major determinant of allergenic potency; however, electrophilic strength does not seem to predict the ability of a hapten to skew the response between Th1 and Th2. Modern proteomic mass spectrometry methods that allow detailed delineation of potential differences in protein binding sites may be valuable in predicting if a chemical will stimulate an immediate or delayed hypersensitivity. Chemical aspects related to both reactivity and protein-specific binding are discussed.
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