1
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Ta GH, Weng CF, Leong MK. Development of a hierarchical support vector regression-based in silico model for the prediction of the cysteine depletion in DPRA. Toxicology 2024; 503:153739. [PMID: 38307191 DOI: 10.1016/j.tox.2024.153739] [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: 12/18/2023] [Revised: 01/22/2024] [Accepted: 01/28/2024] [Indexed: 02/04/2024]
Abstract
Topical and transdermal treatments have been dramatically growing recently and it is crucial to consider skin sensitization during the drug discovery and development process for these administration routes. Various tests, including animal and non-animal approaches, have been devised to assess the potential for skin sensitization. Furthermore, numerous in silico models have been created, providing swift and cost-effective alternatives to traditional methods such as in vivo, in vitro, and in chemico methods for categorizing compounds. In this study, a quantitative structure-activity relationship (QSAR) model was developed using the innovative hierarchical support vector regression (HSVR) scheme. The aim was to quantitatively predict the potential for skin sensitization by analyzing the percent of cysteine depletion in Direct Peptide Reactivity Assay (DPRA). The results demonstrated accurate, consistent, and robust predictions in the training set, test set, and outlier set. Consequently, this model can be employed to estimate skin sensitization potential of novel or virtual compounds.
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Affiliation(s)
- Giang H Ta
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974301, Taiwan
| | - Ching-Feng Weng
- Institute of Respiratory Disease Department of Basic Medical Science Xiamen Medical College, Xiamen 361023, Fujian, China
| | - Max K Leong
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974301, Taiwan.
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2
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Zhang J, Zhang M, Bhandari B, Wang M. Basic sensory properties of essential oils from aromatic plants and their applications: a critical review. Crit Rev Food Sci Nutr 2023; 64:6990-7003. [PMID: 36803316 DOI: 10.1080/10408398.2023.2177611] [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] [Indexed: 02/22/2023]
Abstract
With higher standards in terms of diet and leisure enjoyment, spices and essential oils of aromatic plants (APEOs) are no longer confined to the food industry. The essential oils (EOs) produced from them are the active ingredients that contribute to different flavors. The multiple odor sensory properties and their taste characteristics of APEOs are responsible for their widespread use. The research on the flavor of APEOs is an evolving process attracting the attention among scientists in the past decades. For APEOs, which are used for a long time in the catering and leisure industries, it is necessary to analyze the components associated with the aromas and the tastes. It is important to identify the volatile components and assure quality of APEOs in order to expand their application. It is worth celebrating the different means by which the loss of flavor of APEOs can be retarded in practice. Unfortunately, relatively little research has been done on the structure and flavor mechanisms of APEOs. This also points the way to future research on APEOs.Therefore, this paper reviews the principles of flavor, identification of components and sensory pathways in humans for APEOs. Moreover, the article outlines the means of increasing the efficiency of using of APEOs. Finally, with respect to the sensory applications of APEOs, the review focuses on the practical application of APEOs in food sector and in aromatherapy.
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Affiliation(s)
- Jiong Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
- China General Chamber of Commerce Key Laboratory on Fresh Food Processing & Preservation, Jiangnan University, Wuxi, China
| | - Min Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
- Jiangsu Province International Joint Laboratory on Fresh Food Smart Processing and Quality Monitoring, Jiangnan University, Wuxi, China
| | - Bhesh Bhandari
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Mingqi Wang
- R & D Center, Zhengzhou Xuemailong Food Flavor Co, Zhengzhou, China
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3
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Pemberton MA, Kimber I. Propylene glycol, skin sensitisation and allergic contact dermatitis: A scientific and regulatory conundrum. Regul Toxicol Pharmacol 2023; 138:105341. [PMID: 36702195 DOI: 10.1016/j.yrtph.2023.105341] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/15/2023] [Accepted: 01/21/2023] [Indexed: 01/25/2023]
Abstract
Propylene glycol (PG) has widespread use in pharmaceuticals, cosmetics, fragrances and personal care products. PG is not classified as hazardous under the Globally Harmonised System of Classification and Labelling of Chemicals (GHS) but poses an intriguing scientific and regulatory conundrum with respect to allergic contact dermatitis (ACD), the uncertainty being whether and to what extent PG has the potential to induce skin sensitisation. In this article we review the results of predictive tests for skin sensitisation with PG, and clinical evidence for ACD. Patch testing in humans points to PG having the potential to be a weak allergen under certain conditions, and an uncommon cause of ACD in subjects without underlying/pre-disposing skin conditions. In clear contrast PG is negative in predictive toxicology tests for skin sensitisation, including guinea pig and mouse models (e.g. local lymph node assay), validated in vitro test methods that measure various key events in the pathway leading to skin sensitisation, and predictive methods in humans (Human Repeat Insult Patch and Human Maximisation Tests). We here explore the possible scientific basis for this intriguing inconsistency, recognising there are arguably no known contact allergens that are universally negative in, in vitro, animal and human predictive tests methods.
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Affiliation(s)
| | - Ian Kimber
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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4
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Townsend P, Farrar EHE, Grayson MN. Eliminating Transition State Calculations for Faster and More Accurate Reactivity Prediction in Sulfa-Michael Additions Relevant to Human Health and the Environment. ACS OMEGA 2022; 7:26945-26951. [PMID: 35936424 PMCID: PMC9352231 DOI: 10.1021/acsomega.2c03739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
Fast and accurate computational approaches to predicting reactivity in sulfa-Michael additions are required for high-throughput screening in toxicology (e.g., predicting excess aquatic toxicity and skin sensitization), chemical synthesis, covalent drug design (e.g., targeting cysteine), and data set generation for machine learning. The kinetic glutathione chemoassay is a time-consuming in chemico method used to extract kinetic data in the form of log(k GSH) for organic electrophiles. In this work, we use density functional theory to compare the use of transition states (TSs) and enolate intermediate structures following C-S bond formation in the prediction of log(k GSH) for a diverse group of 1,4 Michael acceptors. Despite the widespread use of transition state calculations in the literature to predict sulfa-Michael reactivity, we observe that intermediate structures show much better performance for the prediction of log(k GSH), are faster to calculate, and easier to obtain than TSs. Furthermore, we show how linear combinations of atomic charges from the isolated Michael acceptors can further improve predictions, even when using inexpensive semiempirical quantum chemistry methods. Our models can be used widely in the chemical sciences (e.g., in the prediction of toxicity relevant to the environment and human health, synthesis planning, and the design of cysteine-targeting covalent inhibitors), and represent a low-cost, sustainable approach to reactivity assessment.
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Affiliation(s)
- Piers
A. Townsend
- Centre
for Sustainable Chemical Technologies, Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
| | - Elliot H. E. Farrar
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
| | - Matthew N. Grayson
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
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5
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Bustamante C, Muskus C, Ochoa R. Rational computational approaches to predict novel drug candidates against leishmaniasis. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2022. [DOI: 10.1016/bs.armc.2022.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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6
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Monnot AD, Towle KM, Ahmed SS, Dickinson AM, Fung ES. An in vitro human assay for evaluating immunogenic and sensitization potential of a personal care and cosmetic product. Toxicol Mech Methods 2021; 31:205-211. [PMID: 33371753 DOI: 10.1080/15376516.2020.1868640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
With the reduction or elimination of animal testing, manufacturers are left with limited options, as few robust in vitro tests are available and human studies are costly. Recently, concerns have been raised regarding potential adverse health effects associated with use of WEN by Chaz Dean (WCD) cleansing conditioners. The purpose of this study was to evaluate the immunogenic potential of a WCD hair cleansing conditioner by utilizing a novel in vitro human skin explant test. Peripheral blood mononuclear cells (PBMCs) and human skin biopsies were obtained from healthy volunteers. Monocyte derived dendritic cells (MoDCs) were generated, primed by 0.01% WCD cleansing conditioner exposure for 24 h, co-cultured with autologous lymphocytes for 4 days, and then cultured with skin biopsies for 3 days. The skin biopsies then underwent histopathological evaluation, and T cell proliferation and IFNγ levels were determined. Overall, this study showed that treatment with 0.01% WCD cleansing conditioner resulted in a negative prediction for in vivo immune response. Further, this analysis shows that the skin explant test is a viable alternative to animal testing for complex mixtures or commercially available products.
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Affiliation(s)
| | | | | | - Anne M Dickinson
- Alcyomics Ltd, Newcastle upon Tyne, UK.,Newcastle University Translational and Clinical Research Institute, Newcastle upon Tyne, UK
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7
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Kimber I. The activity of methacrylate esters in skin sensitisation test methods II. A review of complementary and additional analyses. Regul Toxicol Pharmacol 2020; 119:104821. [PMID: 33186628 DOI: 10.1016/j.yrtph.2020.104821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 10/29/2020] [Accepted: 11/05/2020] [Indexed: 01/13/2023]
Abstract
Allergic contact dermatitis is an important occupational health issue, and there is a need to identify accurately those chemicals that have the potential to induce skin sensitisation. Hazard identification was performed initially using animal (guinea pig and mouse) models. More recently, as a result of the drive towards non-animal methods, alternative in vitro and in silico approaches have been developed. Some of these new in vitro methods have been formally validated and have been assigned OECD Test Guideline status. The performance of some of these recently developed in vitro methods, and of 2 quantitative structure-activity relationships (QSAR) approaches, with a series of methacrylate esters has been reviewed and reported previously. In this article that first review has been extended further with additional data and complementary analyses. Results obtained using in vitro methods (Direct Peptide Reactivity Assay, DPRA; ARE-Nrf2 luciferase test methods, KeratinoSens and LuSens; Epidermal Sensitisation Assay, EpiSensA; human Cell Line Activation Test, h-CLAT, and the myeloid U937 Skin Sensitisation test, U-SENS), and 2 QSAR approaches (DEREK™-nexus and TIMES-SS), with 11 methacrylate esters and methacrylic acid are reported here, and compared with existing data from the guinea pig maximisation test and the local lymph node assay. With this series of chemicals it was found that some in vitro tests (DPRA and ARE-Nrf2 luciferase) performed well in comparison with animal test results and available human skin sensitisation data. Other in vitro tests (EpiSensA and h-CLAT) proved rather more problematic. Results with DEREK™-nexus and TIMES-SS failed to reflect accurately the skin sensitisation potential of the methacrylate esters. The implications for assessment of skin sensitising activity are discussed.
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Affiliation(s)
- Ian Kimber
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
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8
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Townsend PA, Grayson MN. Reactivity prediction in aza-Michael additions without transition state calculations: the Ames test for mutagenicity. Chem Commun (Camb) 2020; 56:13661-13664. [PMID: 33073273 DOI: 10.1039/d0cc05681b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Animal testing remains a contentious ethical issue in predictive toxicology. Thus, a fast, versatile, low-cost quantum chemical model is presented for predicting the risk of Ames mutagenicity in a series of 1,4 Michael acceptor type compounds. This framework eliminates the need for transition state calculations, and uses an intermediate structure to probe the reactivity of aza-Michael acceptors. This model can be used in a variety of settings e.g., the design of targeted covalent inhibitors and polyketide biosyntheses.
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Affiliation(s)
- Piers A Townsend
- Centre for Sustainable Chemical Technologies, University of Bath, Claverton Down, Bath, BA2 7AY, UK
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9
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Kimber I. The activity of methacrylate esters in skin sensitisation test methods: A review. Regul Toxicol Pharmacol 2019; 104:14-20. [PMID: 30826317 DOI: 10.1016/j.yrtph.2019.02.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 02/19/2019] [Accepted: 02/22/2019] [Indexed: 10/27/2022]
Abstract
Skin sensitisation associated with allergic contact dermatitis is an important occupational and environmental disease. The identification of skin sensitisation hazards was traditionally performed using animal tests; originally guinea pig assays and subsequently the murine local lymph node assay (LLNA). More recently there has, for a variety of reasons, been an increased interest in, and requirement for, non-animal assays. There are now available both validated in vitro assays and a variety of approaches based on consideration of quantitative structure-activity relationships (QSAR). With the increased availability and use of non-animal alternatives for skin sensitisation testing there is a continuing need to monitor the performance of these approaches using series of chemicals that do not normally form part of validation exercises. Here we report studies conducted with 11 methacrylate esters and methacrylic acid in which results obtained with 3 validated in vitro tests for which there are OECD guidelines (the Direct Peptide Reactivity Assay, DPRA; ARE-Nrf2 luciferase test methods, and - with some chemicals - a dendritic cell activation test, the myeloid U937 Skin Sensitisation test [U-SENS] assay) have been compared with QSAR approaches (DEREK and TIMES-SS), and with LLNA and guinea pig maximisation test (GPMT) data. The conclusions drawn from these data are that - with this series of chemicals at least - there is a strong correlation between the results of animal tests and the in vitro assays considered, but not with either DEREK or TIMES-SS.
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Affiliation(s)
- Ian Kimber
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
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10
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Clippinger AJ, Allen D, Behrsing H, BéruBé KA, Bolger MB, Casey W, DeLorme M, Gaça M, Gehen SC, Glover K, Hayden P, Hinderliter P, Hotchkiss JA, Iskandar A, Keyser B, Luettich K, Ma-Hock L, Maione AG, Makena P, Melbourne J, Milchak L, Ng SP, Paini A, Page K, Patlewicz G, Prieto P, Raabe H, Reinke EN, Roper C, Rose J, Sharma M, Spoo W, Thorne PS, Wilson DM, Jarabek AM. Pathway-based predictive approaches for non-animal assessment of acute inhalation toxicity. Toxicol In Vitro 2018; 52:131-145. [PMID: 29908304 PMCID: PMC6760245 DOI: 10.1016/j.tiv.2018.06.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/01/2018] [Accepted: 06/08/2018] [Indexed: 01/14/2023]
Abstract
New approaches are needed to assess the effects of inhaled substances on human health. These approaches will be based on mechanisms of toxicity, an understanding of dosimetry, and the use of in silico modeling and in vitro test methods. In order to accelerate wider implementation of such approaches, development of adverse outcome pathways (AOPs) can help identify and address gaps in our understanding of relevant parameters for model input and mechanisms, and optimize non-animal approaches that can be used to investigate key events of toxicity. This paper describes the AOPs and the toolbox of in vitro and in silico models that can be used to assess the key events leading to toxicity following inhalation exposure. Because the optimal testing strategy will vary depending on the substance of interest, here we present a decision tree approach to identify an appropriate non-animal integrated testing strategy that incorporates consideration of a substance's physicochemical properties, relevant mechanisms of toxicity, and available in silico models and in vitro test methods. This decision tree can facilitate standardization of the testing approaches. Case study examples are presented to provide a basis for proof-of-concept testing to illustrate the utility of non-animal approaches to inform hazard identification and risk assessment of humans exposed to inhaled substances.
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Affiliation(s)
- Amy J Clippinger
- PETA International Science Consortium Ltd., Society Building, 8 All Saints Street, London N1 9RL, United Kingdom.
| | - David Allen
- Integrated Laboratory Systems, Contractor Supporting the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods, Research Triangle Park, NC, United States
| | - Holger Behrsing
- Institute for In Vitro Sciences, 30 West Watkins Mill Road, Suite 100, Gaithersburg, MD 20878, United States
| | - Kelly A BéruBé
- Cardiff School of Biosciences, Museum Avenue, CF10 3AX, Wales, United Kingdom
| | - Michael B Bolger
- Simulations Plus, Inc., 42505 10th Street West, Lancaster, CA 93534, United States
| | - Warren Casey
- NIH/NIEHS/DNTP/NICEATM, Research Triangle Park, North Carolina 27709, United States
| | | | - Marianna Gaça
- British American Tobacco plc, Globe House, 4 Temple Place, London WC2R 2PG, United Kingdom
| | - Sean C Gehen
- Dow AgroSciences, Indianapolis, IN, United States
| | - Kyle Glover
- Defense Threat Reduction Agency, Aberdeen Proving Ground, MD 21010, United States
| | - Patrick Hayden
- MatTek Corporation, 200 Homer Ave, Ashland, MA 01721, United States
| | | | | | - Anita Iskandar
- Philip Morris Products SA, Philip Morris International R&D, Neuchâtel, Switzerland
| | - Brian Keyser
- RAI Services Company, 401 North Main Street, Winston-Salem, NC 27101, United States
| | - Karsta Luettich
- Philip Morris Products SA, Philip Morris International R&D, Neuchâtel, Switzerland
| | - Lan Ma-Hock
- BASF SE, Carl-Bosch-Strasse 38, 67056 Ludwigshafen am Rhein, Germany
| | - Anna G Maione
- MatTek Corporation, 200 Homer Ave, Ashland, MA 01721, United States
| | - Patrudu Makena
- RAI Services Company, 401 North Main Street, Winston-Salem, NC 27101, United States
| | - Jodie Melbourne
- PETA International Science Consortium Ltd., Society Building, 8 All Saints Street, London N1 9RL, United Kingdom
| | | | - Sheung P Ng
- E.I. du Pont de Nemours and Company, DuPont Haskell Global Center for Health Sciences, P. O. Box 30, Newark, DE 19714, United States
| | - Alicia Paini
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Kathryn Page
- The Clorox Company, 4900 Johnson Dr, Pleasanton, CA 94588, United States
| | - Grace Patlewicz
- U.S. Environmental Protection Agency, Office of Research and Development, National Center for Computational Toxicology, Research Triangle Park, NC, United States
| | - Pilar Prieto
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Hans Raabe
- Institute for In Vitro Sciences, 30 West Watkins Mill Road, Suite 100, Gaithersburg, MD 20878, United States
| | - Emily N Reinke
- U.S. Army Public Health Center, 8252 Blackhawk Rd. Bldg. E-5158, ATTN: MCHB-PH-HEF Gunpowder, MD 21010-5403, United States
| | - Clive Roper
- Charles River Edinburgh Ltd., Edinburgh EH33 2NE, United Kingdom
| | - Jane Rose
- Procter & Gamble Co, 11530 Reed Hartman Highway, Cincinnati, OH 45241, United States
| | - Monita Sharma
- PETA International Science Consortium Ltd., Society Building, 8 All Saints Street, London N1 9RL, United Kingdom
| | - Wayne Spoo
- RAI Services Company, 401 North Main Street, Winston-Salem, NC 27101, United States
| | - Peter S Thorne
- University of Iowa College of Public Health, Iowa City, IA, United States
| | | | - Annie M Jarabek
- U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, Research Triangle Park, NC, United States
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11
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Fitzpatrick JM, Roberts DW, Patlewicz G. An evaluation of selected (Q)SARs/expert systems for predicting skin sensitisation potential. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2018; 29:439-468. [PMID: 29676182 PMCID: PMC6077848 DOI: 10.1080/1062936x.2018.1455223] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 03/17/2018] [Indexed: 06/08/2023]
Abstract
Predictive testing to characterise substances for their skin sensitisation potential has historically been based on animal models such as the Local Lymph Node Assay (LLNA) and the Guinea Pig Maximisation Test (GPMT). In recent years, EU regulations, have provided a strong incentive to develop non-animal alternatives, such as expert systems software. Here we selected three different types of expert systems: VEGA (statistical), Derek Nexus (knowledge-based) and TIMES-SS (hybrid), and evaluated their performance using two large sets of animal data: one set of 1249 substances from eChemportal and a second set of 515 substances from NICEATM. A model was considered successful at predicting skin sensitisation potential if it had at least the same balanced accuracy as the LLNA and the GPMT had in predicting the other outcomes, which ranged from 79% to 86%. We found that the highest balanced accuracy of any of the expert systems evaluated was 65% when making global predictions. For substances within the domain of TIMES-SS, however, balanced accuracies for the two datasets were found to be 79% and 82%. In those cases where a chemical was within the TIMES-SS domain, the TIMES-SS skin sensitisation hazard prediction had the same confidence as the result from LLNA or GPMT.
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Affiliation(s)
- Jeremy M Fitzpatrick
- National Center for Computational Toxicology (NCCT), US Environmental Protection Agency (US EPA), 109 T W Alexander Dr, Research Triangle Park (RTP), NC 27711, USA
| | - David W Roberts
- School of Pharmacy, Liverpool John Moores University, Byrom Street, Liverpool, UK
| | - Grace Patlewicz
- National Center for Computational Toxicology (NCCT), US Environmental Protection Agency (US EPA), 109 T W Alexander Dr, Research Triangle Park (RTP), NC 27711, USA
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12
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Parkinson E, Aleksic M, Cubberley R, Kaur-Atwal G, Vissers JPC, Skipp P. Determination of Protein Haptenation by Chemical Sensitizers Within the Complexity of the Human Skin Proteome. Toxicol Sci 2018; 162:429-438. [PMID: 29267982 PMCID: PMC5889026 DOI: 10.1093/toxsci/kfx265] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Skin sensitization associated with the development of allergic contact dermatitis occurs via a number of specific key events at the cellular level. The molecular initiating event (MIE), the first in the sequence of these events, occurs after exposure of the skin to an electrophilic chemical, causing the irreversible haptenation of proteins within skin. Characterization of this MIE is a key step in elucidating the skin sensitization adverse outcome pathway and is essential to providing parameters for mathematical models to predict the capacity of a chemical to cause sensitization. As a first step to addressing this challenge, we have exposed complex protein lysates from a keratinocyte cell line and human skin tissue with a range of well characterized sensitizers, including dinitrochlorobenzene, 5-chloro-2-methylisothiazol-3-one, cinnamaldehyde, and the non (or weak) sensitizer 6-methyl coumarin. Using a novel stable isotope labeling approach combined with ion mobility-assisted data independent mass spectrometry (HDMSE), we have characterized the haptenome for these sensitizers. Although a significant proportion of highly abundant proteins were haptenated, we also observed the haptenation of low abundant proteins by all 3 of the chemical sensitizers tested, indicating that within a complex protein background, protein abundance is not the sole determinant driving haptenation, highlighting a relationship to tertiary protein structure and the amino acid specificity of these chemical sensitizers and sensitizer potency.
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Affiliation(s)
- Erika Parkinson
- Centre for Biological Sciences
- Centre for Proteomic Research, Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Maja Aleksic
- Safety & Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook MK44 1LQ, UK
| | - Richard Cubberley
- Safety & Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook MK44 1LQ, UK
| | | | | | - Paul Skipp
- Centre for Biological Sciences
- Centre for Proteomic Research, Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
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13
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Abstract
For toxicologists who are in any way associated with skin sensitisation, the last two decades have seen a series of fundamental changes. We have migrated from old-style guinea-pig assays, via the refined and reduced Local Lymph Node Assay (LLNA), to witness the imminent dominance of in vitro and in silico methods. Yet, over the same period, the use of the output data for human safety assurance has evolved from ‘black box’ risk assessment, via the quantitative risk assessment enabled by the LLNA measurement of potency, to a new period of relative uncertainty. This short review will endeavour to address these topics, all the while keeping a focus on three essential principles: a) that skin sensitisation potential is intrinsic in the molecular structure of the chemical; b) that test methods should have a mechanistic foundation; and finally c) that the only reason for undertaking any skin sensitisation work has to be the protection of human health.
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14
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Fitzpatrick JM, Roberts DW, Patlewicz G. Is skin penetration a determining factor in skin sensitization potential and potency? Refuting the notion of a LogKow threshold for skin sensitization. J Appl Toxicol 2016; 37:117-127. [PMID: 27357739 DOI: 10.1002/jat.3354] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 04/21/2016] [Accepted: 05/09/2016] [Indexed: 11/09/2022]
Abstract
It is widely accepted that substances that cannot penetrate through the skin will not be sensitizers. LogKow and molecular weight (MW) have been used to set thresholds for sensitization potential. Highly hydrophilic substances e.g. LogKow ≤ 1 are expected not to penetrate effectively to induce sensitization. To investigate whether LogKow >1 is a true requirement for sensitization, a large dataset of substances that had been evaluated for their skin sensitization potential under Registration, Evaluation, Authorisation and restriction of CHemicals (REACH), together with available measured LogKow values was compiled using the OECD eChemPortal. The incidence of sensitizers relative to non-sensitizers above and below a LogKow of 1 was explored. Reaction chemistry principles were used to explain the sensitization observed for the subset of substances with a LogKow ≤0. 1482 substances were identified with skin sensitization data and measured LogKow values. 525 substances had a measured LogKow ≤ 1, 100 of those were sensitizers. There was no significant difference in the incidence of sensitizers above and below a LogKow of 1. Reaction chemistry principles that had been established for lower MW and more hydrophobic substances were found to be still valid in rationalizing the skin sensitizers with a LogKow ≤ 0. The LogKow threshold arises from the widespread misconception that the ability to efficiently penetrate the stratum corneum is a key determinant of sensitization potential and potency. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Jeremy M Fitzpatrick
- National Center for Computational Toxicology (NCCT), US Environmental Protection Agency (US EPA), USA
| | - David W Roberts
- School of Pharmacy and Chemistry, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Grace Patlewicz
- National Center for Computational Toxicology (NCCT), US Environmental Protection Agency (US EPA), USA
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15
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Integrated Computational Solution for Predicting Skin Sensitization Potential of Molecules. PLoS One 2016; 11:e0155419. [PMID: 27271321 PMCID: PMC4896476 DOI: 10.1371/journal.pone.0155419] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 04/28/2016] [Indexed: 11/29/2022] Open
Abstract
Introduction Skin sensitization forms a major toxicological endpoint for dermatology and cosmetic products. Recent ban on animal testing for cosmetics demands for alternative methods. We developed an integrated computational solution (SkinSense) that offers a robust solution and addresses the limitations of existing computational tools i.e. high false positive rate and/or limited coverage. Results The key components of our solution include: QSAR models selected from a combinatorial set, similarity information and literature-derived sub-structure patterns of known skin protein reactive groups. Its prediction performance on a challenge set of molecules showed accuracy = 75.32%, CCR = 74.36%, sensitivity = 70.00% and specificity = 78.72%, which is better than several existing tools including VEGA (accuracy = 45.00% and CCR = 54.17% with ‘High’ reliability scoring), DEREK (accuracy = 72.73% and CCR = 71.44%) and TOPKAT (accuracy = 60.00% and CCR = 61.67%). Although, TIMES-SS showed higher predictive power (accuracy = 90.00% and CCR = 92.86%), the coverage was very low (only 10 out of 77 molecules were predicted reliably). Conclusions Owing to improved prediction performance and coverage, our solution can serve as a useful expert system towards Integrated Approaches to Testing and Assessment for skin sensitization. It would be invaluable to cosmetic/ dermatology industry for pre-screening their molecules, and reducing time, cost and animal testing.
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16
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Ahmed SS, Wang XN, Fielding M, Kerry A, Dickinson I, Munuswamy R, Kimber I, Dickinson AM. An in vitro human skin test for assessing sensitization potential. J Appl Toxicol 2016; 36:669-84. [PMID: 26251951 DOI: 10.1002/jat.3197] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 05/07/2015] [Accepted: 05/22/2015] [Indexed: 01/08/2023]
Abstract
Sensitization to chemicals resulting in an allergy is an important health issue. The current gold-standard method for identification and characterization of skin-sensitizing chemicals was the mouse local lymph node assay (LLNA). However, for a number of reasons there has been an increasing imperative to develop alternative approaches to hazard identification that do not require the use of animals. Here we describe a human in-vitro skin explant test for identification of sensitization hazards and the assessment of relative skin sensitizing potency. This method measures histological damage in human skin as a readout of the immune response induced by the test material. Using this approach we have measured responses to 44 chemicals including skin sensitizers, pre/pro-haptens, respiratory sensitizers, non-sensitizing chemicals (including skin-irritants) and previously misclassified compounds. Based on comparisons with the LLNA, the skin explant test gave 95% specificity, 95% sensitivity, 95% concordance with a correlation coefficient of 0.9. The same specificity and sensitivity were achieved for comparison of results with published human sensitization data with a correlation coefficient of 0.91. The test also successfully identified nickel sulphate as a human skin sensitizer, which was misclassified as negative in the LLNA. In addition, sensitizers and non-sensitizers identified as positive or negative by the skin explant test have induced high/low T cell proliferation and IFNγ production, respectively. Collectively, the data suggests the human in-vitro skin explant test could provide the basis for a novel approach for characterization of the sensitizing activity as a first step in the risk assessment process.
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Affiliation(s)
- S S Ahmed
- Alcyomics Ltd, Bulman House, Regent Centre, Gosforth, Newcastle-upon-Tyne, NE3 3LS, UK
| | - X N Wang
- Haematological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK
| | - M Fielding
- Haematological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK
| | - A Kerry
- Haematological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK
| | - I Dickinson
- Haematological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK
| | - R Munuswamy
- Haematological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK
| | - I Kimber
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - A M Dickinson
- Alcyomics Ltd, Bulman House, Regent Centre, Gosforth, Newcastle-upon-Tyne, NE3 3LS, UK
- Haematological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK
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17
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Guedes S, Neves B, Vitorino R, Domingues R, Cruz MT, Domingues P. Contact dermatitis: in pursuit of sensitizer's molecular targets through proteomics. Arch Toxicol 2016; 91:811-825. [PMID: 27129696 DOI: 10.1007/s00204-016-1714-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 04/14/2016] [Indexed: 10/21/2022]
Abstract
Protein haptenation, i.e., the modification of proteins by small reactive chemicals, is the key step in the sensitization phase of allergic contact dermatitis (ACD). Despite the research effort in past decades, the identification of immunogenic hapten-protein complexes that trigger a relevant pathogenic immune response in ACD, as well as the haptenation reaction molecular site, and the elements of a potentially conditioning environment during each of these stages, remain poorly understood. These questions led us to employ a proteomics-based approach to identify modified proteins in the dendritic-like cell line THP-1 sensitized with fluorescein isothiocyanate (FITC), through a combination of 2D-gel electrophoresis, nano-LC and mass spectrometry. A specific set of 39 targeted proteins was identified and comprised proteins from various cellular locations and biological functions. One of FITC targets was identified as MLK, a member of the mixed-lineage kinase family known to act as a mitogen-activated protein kinase kinase kinase and to control the activity of specific mitogen-activated protein kinase pathways, namely p38 and JNK pathways. Haptenated in the vicinity of its active site, our results point to MLK being a relevant target due to a consistent non-activation at early time points of these pathways upon FITC sensitization in THP-1 cells. Moreover, FITC pre-treatment significantly decrease phospho-p38 and phospho-JNK levels induced upon exposure to a classical activator such as lipopolysaccharide or to the sensitizer 2,4-dinitrofluorobenzene. Overall, our data point to specific amino acid residues haptenation within critical proteins as the key step in the subsequent signaling pathways modulation responsible for DC activation and maturation events.
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Affiliation(s)
- Sofia Guedes
- Department of Chemistry, Mass Spectrometry Center, QOPNA, University of Aveiro, Campus Universitario de Santiago, 3810-193, Aveiro, Portugal.
| | - Bruno Neves
- Department of Chemistry, Mass Spectrometry Center, QOPNA, University of Aveiro, Campus Universitario de Santiago, 3810-193, Aveiro, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, 3000-548, Coimbra, Portugal
| | - Rui Vitorino
- Department of Medical Sciences, Institute for Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal.,Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Rosário Domingues
- Department of Chemistry, Mass Spectrometry Center, QOPNA, University of Aveiro, Campus Universitario de Santiago, 3810-193, Aveiro, Portugal
| | - Maria Teresa Cruz
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, 3000-548, Coimbra, Portugal
| | - Pedro Domingues
- Department of Chemistry, Mass Spectrometry Center, QOPNA, University of Aveiro, Campus Universitario de Santiago, 3810-193, Aveiro, Portugal.
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18
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Kimber I, Pemberton MA. Assessment of the skin sensitising potency of the lower alkyl methacrylate esters. Regul Toxicol Pharmacol 2014; 70:24-36. [PMID: 24956587 DOI: 10.1016/j.yrtph.2014.06.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 06/11/2014] [Accepted: 06/15/2014] [Indexed: 01/08/2023]
Abstract
There is continued interest in, and imperatives for, the classification of contact allergens according to their relative skin sensitising potency. However, achieving that end can prove problematic, not least when there is an apparent lack of concordance between experimental assessments of potency and the prevalence allergic contact dermatitis as judged by clinical experience. For the purpose of exploring this issue, and illustrating the important considerations that are required to reach sound judgements about potency categorisation, the lower alkyl methacrylate esters (LAM) have been employed here as a case study. Although the sensitising potential of methyl methacrylate (MMA) has been reviewed previously, there is available new information that is relevant for assessment of skin sensitising potency. Moreover, for the purposes of this article, analyses have been extended to include also other LAM for which relevant data are available: ethyl methacrylate (EMA), n-butyl methacrylate (nBMA), isobutyl methacrylate (iBMA), and 2-ethylhexyl methacrylate (EHMA). In addressing the skin sensitising activity of these chemicals and in drawing conclusions regarding relative potency, a number of sources of information has been considered, including estimates of potency derived from local lymph node assay (LLNA) data, the results of guinea pig assays, and data derived from in silico methods and from recently developed in vitro approaches. Moreover, clinical experience of skin sensitisation of humans by LAM has also been evaluated. The conclusion drawn is that MMA and other LAM are contact allergens, but that none of these chemicals has any more than weak skin sensitising potency. We have also explored here the possible bases for this modest sensitising activity. Finally, the nature of exposure to LAM has been reviewed briefly and on the basis of that information, together with an understanding of skin sensitising potency, a risk assessment has been prepared.
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Affiliation(s)
- Ian Kimber
- Faculty of Life Sciences, University of Manchester, Manchester, UK
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19
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Safety Evaluation of Cosmetic Ingredients: In Vitro Opportunities for the Identification of Contact Allergens. COSMETICS 2014. [DOI: 10.3390/cosmetics1010061] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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20
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Johansson H, Lindstedt M. Prediction of Skin Sensitizers using Alternative Methods to Animal Experimentation. Basic Clin Pharmacol Toxicol 2014; 115:110-7. [DOI: 10.1111/bcpt.12199] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 01/13/2014] [Indexed: 01/04/2023]
Affiliation(s)
| | - Malin Lindstedt
- Department of Immunotechnology; Lund University; Lund Sweden
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21
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Approaches and considerations for the assessment of immunotoxicity for environmental chemicals: A workshop summary. Regul Toxicol Pharmacol 2014; 68:96-107. [DOI: 10.1016/j.yrtph.2013.11.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 11/14/2013] [Accepted: 11/17/2013] [Indexed: 12/31/2022]
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22
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Vocanson M, Nicolas JF, Basketter D. In vitroapproaches to the identification and characterization of skin sensitizers. ACTA ACUST UNITED AC 2014. [DOI: 10.1586/17469872.2013.814882] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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23
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24
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Putz MV, Dudaş NA. Determining chemical reactivity driving biological activity from SMILES transformations: the bonding mechanism of anti-HIV pyrimidines. Molecules 2013; 18:9061-116. [PMID: 23903183 PMCID: PMC6270382 DOI: 10.3390/molecules18089061] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 07/22/2013] [Accepted: 07/24/2013] [Indexed: 02/08/2023] Open
Abstract
Assessing the molecular mechanism of a chemical-biological interaction and bonding stands as the ultimate goal of any modern quantitative structure-activity relationship (QSAR) study. To this end the present work employs the main chemical reactivity structural descriptors (electronegativity, chemical hardness, chemical power, electrophilicity) to unfold the variational QSAR though their min-max correspondence principles as applied to the Simplified Molecular Input Line Entry System (SMILES) transformation of selected uracil derivatives with anti-HIV potential with the aim of establishing the main stages whereby the given compounds may inhibit HIV infection. The bonding can be completely described by explicitly considering by means of basic indices and chemical reactivity principles two forms of SMILES structures of the pyrimidines, the Longest SMILES Molecular Chain (LoSMoC) and the Branching SMILES (BraS), respectively, as the effective forms involved in the anti-HIV activity mechanism and according to the present work, also necessary intermediates in molecular pathways targeting/docking biological sites of interest.
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Affiliation(s)
- Mihai V Putz
- Laboratory of Computational and Structural Physical Chemistry for Nanosciences and QSAR, Biology-Chemistry Department, West University of Timişoara, Pestalozzi Str. No. 16, Timişoara 300115, Romania.
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25
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Applicability of a keratinocyte gene signature to predict skin sensitizing potential. Toxicol In Vitro 2013; 27:314-22. [DOI: 10.1016/j.tiv.2012.08.023] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 08/16/2012] [Accepted: 08/17/2012] [Indexed: 01/19/2023]
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26
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27
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Roberts DW, Aptula AO, Patlewicz GY. Chemistry-Based Risk Assessment for Skin Sensitization: Quantitative Mechanistic Modeling for the SNAr Domain. Chem Res Toxicol 2011; 24:1003-11. [DOI: 10.1021/tx100420w] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- D. W. Roberts
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England
| | - A. O. Aptula
- SEAC, Unilever Colworth, Sharnbrook, Bedford MK44 1LQ, England
| | - G. Y. Patlewicz
- DuPont Haskell Global Centers for Health and Environmental Sciences, Newark, Delaware 19711, United States
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28
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The LLNA: A Brief Review of Recent Advances and Limitations. J Allergy (Cairo) 2011; 2011:424203. [PMID: 21747867 PMCID: PMC3124934 DOI: 10.1155/2011/424203] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Accepted: 03/31/2011] [Indexed: 11/18/2022] Open
Abstract
Allergic contact dermatitis is the second most commonly reported occupational illness, accounting for 10% to 15% of all occupational diseases. This highlights the importance of developing rapid and sensitive methods for hazard identification of chemical sensitizers. The murine local lymph node assay (LLNA) was developed and validated for the identification of low molecular weight sensitizing chemicals. It provides several benefits over other tests for sensitization because it provides a quantitative endpoint, dose-responsive data, and allows for prediction of potency. However, there are also several concerns with this assay including: levels of false positive responses, variability due to vehicle, and predictivity. This report serves as a concise review which briefly summarizes the progress, advances and limitations of the assay over the last decade.
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29
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Adler S, Basketter D, Creton S, Pelkonen O, van Benthem J, Zuang V, Andersen KE, Angers-Loustau A, Aptula A, Bal-Price A, Benfenati E, Bernauer U, Bessems J, Bois FY, Boobis A, Brandon E, Bremer S, Broschard T, Casati S, Coecke S, Corvi R, Cronin M, Daston G, Dekant W, Felter S, Grignard E, Gundert-Remy U, Heinonen T, Kimber I, Kleinjans J, Komulainen H, Kreiling R, Kreysa J, Leite SB, Loizou G, Maxwell G, Mazzatorta P, Munn S, Pfuhler S, Phrakonkham P, Piersma A, Poth A, Prieto P, Repetto G, Rogiers V, Schoeters G, Schwarz M, Serafimova R, Tähti H, Testai E, van Delft J, van Loveren H, Vinken M, Worth A, Zaldivar JM. Alternative (non-animal) methods for cosmetics testing: current status and future prospects-2010. Arch Toxicol 2011; 85:367-485. [PMID: 21533817 DOI: 10.1007/s00204-011-0693-2] [Citation(s) in RCA: 358] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 03/03/2011] [Indexed: 01/09/2023]
Abstract
The 7th amendment to the EU Cosmetics Directive prohibits to put animal-tested cosmetics on the market in Europe after 2013. In that context, the European Commission invited stakeholder bodies (industry, non-governmental organisations, EU Member States, and the Commission's Scientific Committee on Consumer Safety) to identify scientific experts in five toxicological areas, i.e. toxicokinetics, repeated dose toxicity, carcinogenicity, skin sensitisation, and reproductive toxicity for which the Directive foresees that the 2013 deadline could be further extended in case alternative and validated methods would not be available in time. The selected experts were asked to analyse the status and prospects of alternative methods and to provide a scientifically sound estimate of the time necessary to achieve full replacement of animal testing. In summary, the experts confirmed that it will take at least another 7-9 years for the replacement of the current in vivo animal tests used for the safety assessment of cosmetic ingredients for skin sensitisation. However, the experts were also of the opinion that alternative methods may be able to give hazard information, i.e. to differentiate between sensitisers and non-sensitisers, ahead of 2017. This would, however, not provide the complete picture of what is a safe exposure because the relative potency of a sensitiser would not be known. For toxicokinetics, the timeframe was 5-7 years to develop the models still lacking to predict lung absorption and renal/biliary excretion, and even longer to integrate the methods to fully replace the animal toxicokinetic models. For the systemic toxicological endpoints of repeated dose toxicity, carcinogenicity and reproductive toxicity, the time horizon for full replacement could not be estimated.
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Affiliation(s)
- Sarah Adler
- Centre for Documentation and Evaluation of Alternatives to Animal Experiments (ZEBET), Federal Institute for Risk Assessment (BfR), Berlin, Germany
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30
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Ellison CM, Sherhod R, Cronin MTD, Enoch SJ, Madden JC, Judson PN. Assessment of Methods To Define the Applicability Domain of Structural Alert Models. J Chem Inf Model 2011; 51:975-85. [DOI: 10.1021/ci1000967] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- C. M. Ellison
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England
| | - R. Sherhod
- Department of Information Studies, University of Sheffield, Regent Court, Sheffield S1 4DP, England
| | - M. T. D. Cronin
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England
| | - S. J. Enoch
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England
| | - J. C. Madden
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England
| | - P. N. Judson
- Lhasa Limited, 22-23 Blenheim Terrace, Woodhouse Lane, Leeds LS2 9HD, England
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31
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Borak J, Fields C, Andrews LS, Pemberton MA. Methyl methacrylate and respiratory sensitization: a critical review. Crit Rev Toxicol 2011; 41:230-68. [PMID: 21401327 PMCID: PMC3072694 DOI: 10.3109/10408444.2010.532768] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Accepted: 10/14/2010] [Indexed: 12/16/2022]
Abstract
Methyl methacrylate (MMA) is a respiratory irritant and dermal sensitizer that has been associated with occupational asthma in a small number of case reports. Those reports have raised concern that it might be a respiratory sensitizer. To better understand that possibility, we reviewed the in silico, in chemico, in vitro, and in vivo toxicology literature, and also epidemiologic and occupational medicine reports related to the respiratory effects of MMA. Numerous in silico and in chemico studies indicate that MMA is unlikely to be a respiratory sensitizer. The few in vitro studies suggest that MMA has generally weak effects. In vivo studies have documented contact skin sensitization, nonspecific cytotoxicity, and weakly positive responses on local lymph node assay; guinea pig and mouse inhalation sensitization tests have not been performed. Cohort and cross-sectional worker studies reported irritation of eyes, nose, and upper respiratory tract associated with short-term peaks exposures, but little evidence for respiratory sensitization or asthma. Nineteen case reports described asthma, laryngitis, or hypersensitivity pneumonitis in MMA-exposed workers; however, exposures were either not well described or involved mixtures containing more reactive respiratory sensitizers and irritants. The weight of evidence, both experimental and observational, argues that MMA is not a respiratory sensitizer.
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Affiliation(s)
- Jonathan Borak
- Department of Epidemiology and Public Health, Yale University, New Haven, Connecticut 06510, USA.
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32
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Kimber I, Basketter DA, Gerberick GF, Ryan CA, Dearman RJ. Chemical allergy: translating biology into hazard characterization. Toxicol Sci 2010; 120 Suppl 1:S238-68. [PMID: 21097995 DOI: 10.1093/toxsci/kfq346] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The induction by chemicals of allergic sensitization and allergic disease is an important and challenging branch of toxicology. Skin sensitization resulting in allergic contact dermatitis represents the most common manifestation of immunotoxicity in humans, and many hundreds of chemicals have been implicated as skin sensitizers. There are far fewer chemicals that have been shown to cause sensitization of the respiratory tract and asthma, but the issue is no less important because hazard identification remains a significant challenge, and occupational asthma can be fatal. In all areas of chemical allergy, there have been, and remain still, intriguing challenges where progress has required a close and productive alignment between immunology, toxicology, and clinical medicine. What the authors have sought to do here is to exemplify, within the framework of chemical allergy, how an investment in fundamental research and an improved understanding of relevant biological and biochemical mechanisms can pay important dividends in driving new innovations in hazard identification, hazard characterization, and risk assessment. Here we will consider in turn three specific areas of research in chemical allergy: (1) the role of epidermal Langerhans cells in the development of skin sensitization, (2) T lymphocytes and skin sensitization, and (3) sensitization of the respiratory tract. In each area, the aim is to identify what has been achieved and how that progress has impacted on the development of new approaches to toxicological evaluation. Success has been patchy, and there is still much to be achieved, but the journey has been fascinating and there have been some very important developments. The conclusion drawn is that continued investment in research, if coupled with an appetite for translating the fruits of that research into imaginative new tools for toxicology, should continue to better equip us for tackling the important challenges that remain to be addressed.
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Affiliation(s)
- Ian Kimber
- Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK.
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Abstract
Expert systems offer the facility to predict a toxicity endpoint, as well sometimes as additional relevant information, simply by inputting the chemical structure of a compound. There is now a number of expert systems available, mostly on a commercial basis although a few are free to use or download. This chapter discusses nineteen currently available expert systems, and their performances (if known). Published studies of consensus predictions with these expert systems indicate that these give better results than do individual expert systems.
A test set of compounds with Tetrahymena pyriformis toxicities has been run through the two expert systems known to predict these toxicities; the predictions were quite good, with standard errors of prediction of 0.395 and 0.433 log unit. A further test set of compounds with local lymph node assay skin sensitisation data has been run through seven expert systems, and it was found that consensus predictions were better than were those from any individual expert system.
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Affiliation(s)
- J. C. Dearden
- School of Pharmacy and Chemistry, Liverpool John Moores University Byrom Street Liverpool L3 3AF UK
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Patlewicz G, Mekenyan O, Dimitrova G, Kuseva C, Todorov M, Kotov S, Stoeva S, Donner EM. Can mutagenicity information be useful in an Integrated Testing Strategy (ITS) for skin sensitization? SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2010; 21:619-656. [PMID: 21120753 DOI: 10.1080/1062936x.2010.528447] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Our previous work has investigated the utility of mutagenicity data in the development and application of Integrated Testing Strategies (ITS) for skin sensitization by focusing on the chemical mechanisms at play and substantiating these with experimental data where available. The hybrid expert system TIMES (Tissue Metabolism Simulator) was applied in the identification of the chemical mechanisms since it encodes a comprehensive set of established structure-activity relationships for both skin sensitization and mutagenicity. Based on the evaluation, the experimental determination of mutagenicity was thought to be potentially helpful in the evaluation of skin sensitization potential. This study has evaluated the dataset reported by Wolfreys and Basketter (Cutan. Ocul. Toxicol. 23 (2004), pp. 197-205). Upon an update of the experimental data, the original reported concordance of 68% was found to increase to 88%. There were several compounds that were 'outliers' in the two experimental evaluations which are discussed from a mechanistic basis. The discrepancies were found to be mainly associated with the differences between skin and liver metabolism. Mutagenicity information can play a significant role in evaluating sensitization potential as part of an ITS though careful attention needs to be made to ensure that any information is interpreted in the appropriate context.
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Affiliation(s)
- G Patlewicz
- DuPont Haskell Global Centers for Health and Environmental Sciences, Newark, Delaware, USA.
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35
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Mekenyan O, Patlewicz G, Dimitrova G, Kuseva C, Todorov M, Stoeva S, Kotov S, Donner EM. Use of Genotoxicity Information in the Development of Integrated Testing Strategies (ITS) for Skin Sensitization. Chem Res Toxicol 2010; 23:1519-40. [DOI: 10.1021/tx100161j] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ovanes Mekenyan
- Laboratory of Mathematical Chemistry, “Prof. As. Zlatarov” University, Bourgas, Bulgaria, and DuPont Haskell Global Centers for Health and Environmental Sciences, 1090 Elkton Road, Newark, Delaware 19711
| | - Grace Patlewicz
- Laboratory of Mathematical Chemistry, “Prof. As. Zlatarov” University, Bourgas, Bulgaria, and DuPont Haskell Global Centers for Health and Environmental Sciences, 1090 Elkton Road, Newark, Delaware 19711
| | - Gergana Dimitrova
- Laboratory of Mathematical Chemistry, “Prof. As. Zlatarov” University, Bourgas, Bulgaria, and DuPont Haskell Global Centers for Health and Environmental Sciences, 1090 Elkton Road, Newark, Delaware 19711
| | - Chanita Kuseva
- Laboratory of Mathematical Chemistry, “Prof. As. Zlatarov” University, Bourgas, Bulgaria, and DuPont Haskell Global Centers for Health and Environmental Sciences, 1090 Elkton Road, Newark, Delaware 19711
| | - Milen Todorov
- Laboratory of Mathematical Chemistry, “Prof. As. Zlatarov” University, Bourgas, Bulgaria, and DuPont Haskell Global Centers for Health and Environmental Sciences, 1090 Elkton Road, Newark, Delaware 19711
| | - Stoyanka Stoeva
- Laboratory of Mathematical Chemistry, “Prof. As. Zlatarov” University, Bourgas, Bulgaria, and DuPont Haskell Global Centers for Health and Environmental Sciences, 1090 Elkton Road, Newark, Delaware 19711
| | - Stefan Kotov
- Laboratory of Mathematical Chemistry, “Prof. As. Zlatarov” University, Bourgas, Bulgaria, and DuPont Haskell Global Centers for Health and Environmental Sciences, 1090 Elkton Road, Newark, Delaware 19711
| | - E Maria Donner
- Laboratory of Mathematical Chemistry, “Prof. As. Zlatarov” University, Bourgas, Bulgaria, and DuPont Haskell Global Centers for Health and Environmental Sciences, 1090 Elkton Road, Newark, Delaware 19711
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36
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Galbiati V, Mitjans M, Corsini E. Present and future ofin vitroimmunotoxicology in drug development. J Immunotoxicol 2010; 7:255-67. [DOI: 10.3109/1547691x.2010.509848] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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37
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Vandebriel RJ, Loveren HV. Non-animal sensitization testing: State-of-the-art. Crit Rev Toxicol 2010; 40:389-404. [DOI: 10.3109/10408440903524262] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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38
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Ellison CM, Madden JC, Judson P, Cronin MT. Using In Silico Tools in a Weight of Evidence Approach to Aid Toxicological Assessment. Mol Inform 2010; 29:97-110. [DOI: 10.1002/minf.200900006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 12/14/2009] [Indexed: 11/10/2022]
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Ellison CM, Enoch SJ, Cronin MT, Madden JC, Judson P. Definition of the Applicability Domains of Knowledge-based Predictive Toxicology Expert Systems by Using a Structural Fragment-based Approach. Altern Lab Anim 2009; 37:533-45. [DOI: 10.1177/026119290903700510] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The applicability domain of a (quantitative) structure–activity relationship ([Q]SAR) must be defined, if a model is to be used successfully for toxicity prediction, particularly for regulatory purposes. Previous efforts to set guidelines on the definition of applicability domains have often been biased toward quantitative, rather than qualitative, models. As a result, novel techniques are still required to define the applicability domains of structural alert models and knowledge-based systems. By using Derek for Windows as an example, this study defined the domain for the skin sensitisation structural alert rule-base. This was achieved by fragmenting the molecules within a training set of compounds, then searching the fragments for those created from a test compound. This novel method was able to highlight test chemicals which differed from those in the training set. The information was then used to designate chemicals as being either within or outside the domain of applicability for the structural alert on which that training set was based.
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Affiliation(s)
- Claire M. Ellison
- School of Pharmacy and Chemistry, Liverpool John Moores University, Liverpool, UK
| | - Steven J. Enoch
- School of Pharmacy and Chemistry, Liverpool John Moores University, Liverpool, UK
| | - Mark T.D. Cronin
- School of Pharmacy and Chemistry, Liverpool John Moores University, Liverpool, UK
| | - Judith C. Madden
- School of Pharmacy and Chemistry, Liverpool John Moores University, Liverpool, UK
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40
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Papa E, Luini M, Gramatica P. Quantitative structure-activity relationship modelling of oral acute toxicity and cytotoxic activity of fragrance materials in rodents. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2009; 20:767-779. [PMID: 20024809 DOI: 10.1080/10629360903438669] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Fragrance materials are used as ingredients in many consumer and personal care products. The wide and daily use of these substances, as well as their mainly uncontrolled discharge through domestic sewage, make fragrance materials both potential indoor and outdoor air pollutants which are also connected to possible toxic effects on humans (asthma, allergies, headaches). Unfortunately, little is known about the environmental fate and toxicity of these substances. However, the use of alternative, predictive approaches, such as quantitative structure-activity relationships (QSARs), can help in filling the data gap and in the characterization of the environmental and toxicological profile of these substances. In the proposed study, ordinary least squares regression-based QSAR models were developed for three toxicological endpoints: mouse oral LD(50), inhibition of NADH-oxidase (EC(50) NADH-Ox) and the effect on mitochondrial membrane potential (EC(50) DeltaPsim). Theoretical molecular descriptors were calculated by using DRAGON software, and the best QSAR models were developed according to the principles defined by the Organization for Economic Co-operation and Development.
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Affiliation(s)
- E Papa
- Department of Structural and Functional Biology, University of Insubria, 21100 Varese, Italy.
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41
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Corsini E, Roggen EL. Immunotoxicology: Opportunities for Non-animal Test Development. Altern Lab Anim 2009; 37:387-97. [DOI: 10.1177/026119290903700409] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
At present, several animal-based assays are used to assess immunotoxic effects such as immunosuppression and sensitisation. The use of whole animals, however, presents several secondary issues, including expense, ethical concerns and relevance to human risk assessment. There is a growing belief that non-animal approaches can eliminate these issues without impairing human safety, provided that biological markers are available to identify the immunotoxic potentials of new chemicals to which humans may be exposed. Driven by the 7th Amendment to the EU Cosmetics Directive, the new EU policy on chemicals (the REACH system), proposals to update the European legislation on the protection of animals used in research, and emerging visions and strategies for predicting toxicity, such in vitro methods are likely to play a major role in the near future. The realisation that the immune system can be the target of many chemicals, resulting in a range of adverse effects on the host's health, has raised serious concerns from the public and within the regulatory agencies. Hypersensitivity and immunosuppression are considered the primary focus for developing in vitro methods in immunotoxicology. However, in vitro assays to detect immunostimulation and autoimmunity are also needed. This review of the state-of-the-art in the field of in vitro immunotoxicity, reveals a lack of cell-based immunotoxicity assays for predicting the toxicity of xenobiotics toward the immune system in a simple, fast, economical and reliable way.
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Affiliation(s)
- Emanuela Corsini
- Laboratory of Toxicology, Department of Pharmacological Sciences, Faculty of Pharmacy, University of Milan, Milan, Italy
| | - Erwin L. Roggen
- Department of Pharma Protein Development, Novozymes A/S, Bagsvaerd, Denmark
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42
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Basketter DA, Kimber I. Updating the skin sensitizationin vitrodata assessment paradigm in 2009. J Appl Toxicol 2009; 29:545-50. [DOI: 10.1002/jat.1443] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kimber I, Basketter DA, Dearman RJ. Chemical allergens--what are the issues? Toxicology 2009; 268:139-42. [PMID: 19646501 DOI: 10.1016/j.tox.2009.07.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 07/20/2009] [Accepted: 07/21/2009] [Indexed: 11/27/2022]
Abstract
Chemical allergy describes the adverse health effects that may result when exposure to a chemical elicits an immune response. Allergy develops in two phases. In the first phase, exposure of an inherently susceptible subject results in stimulation of an immune response or immunological priming. If the then sensitised subject is exposed on a subsequent occasion to the same chemical then an accelerated and more aggressive secondary immune response will be provoked resulting in inflammation and the signs and symptoms of a clinically discernible allergic reaction. The two forms of chemical allergy of greatest relevance for occupational toxicology are skin sensitisation resulting in allergic contact dermatitis, and sensitisation of the respiratory tract associated with occupational rhinitis and asthma. In this brief survey we identify what we believe currently represent the key issues and key challenges in these areas.
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Affiliation(s)
- Ian Kimber
- Faculty of Life Sciences, University of Manchester, Faculty of Life Sciences, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK.
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Basketter D, Maxwell G. In VitroApproaches to the Identification and Characterization of Skin Sensitizers. Cutan Ocul Toxicol 2008; 26:359-73. [DOI: 10.1080/15569520701622993] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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46
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Arvidson KB, Valerio LG, Diaz M, Chanderbhan RF. In Silico Toxicological Screening of Natural Products. Toxicol Mech Methods 2008; 18:229-42. [DOI: 10.1080/15376510701856991] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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47
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Marchant CA, Briggs KA, Long A. In Silico Tools for Sharing Data and Knowledge on Toxicity and Metabolism: Derek for Windows, Meteor, and Vitic. Toxicol Mech Methods 2008; 18:177-87. [DOI: 10.1080/15376510701857320] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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48
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Gerberick F, Aleksic M, Basketter D, Casati S, Karlberg AT, Kern P, Kimber I, Lepoittevin JP, Natsch A, Ovigne JM, Rovida C, Sakaguchi H, Schultz T. Chemical reactivity measurement and the predicitve identification of skin sensitisers. The report and recommendations of ECVAM Workshop 64. Altern Lab Anim 2008; 36:215-42. [PMID: 18522487 DOI: 10.1177/026119290803600210] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Frank Gerberick
- Procter & Gamble Company, Miami Valley Innovation Center, Cincinnati, OH 45253, USA.
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49
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Alenius H, Roberts DW, Tokura Y, Lauerma A, Patlewicz G, Roberts MS. Skin, drug and chemical reactions. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.ddmec.2008.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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50
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Patlewicz G, Aptula A, Roberts D, Uriarte E. A Minireview of Available Skin Sensitization (Q)SARs/Expert Systems. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/qsar.200710067] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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