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Colnot T, Dekant W. Grouping of short alkyl-chain branched carboxylic acids for developmental toxicity. Regul Toxicol Pharmacol 2024; 151:105662. [PMID: 38866176 DOI: 10.1016/j.yrtph.2024.105662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 05/27/2024] [Accepted: 06/09/2024] [Indexed: 06/14/2024]
Abstract
Read-across (RAx) and grouping of chemicals into categories are well-known concepts in toxicology. Recently, ECHA proposed a grouping approach for branched-chain carboxylic acids (BCAs) including more than 60 branched-chain saturated carboxylic acids for hazard identification. Grouping was based only on structural considerations. Due to developmental effects of two members, ECHA postulated that "all short carbon chain acids … are likely reproductive and developmental toxicants". This work analyzes available data for BCAs. The number of compounds in the group can be significantly reduced by eliminating metal and organic salts of BCAs, compounds of unknown or variable composition, and complex reaction products or biological materials (UVCB compounds). For the resulting reduced number of compounds, grouping is supported by similar physicochemical data and expected similar biotransformation. However, analysis of adverse effects for compounds in the group and mechanistic information show that BCAs, as a class, do not cause developmental effects in rats. Rather, developmental toxicity is limited to selected BCAs with specific structures that share a common mode of action (histone deacetylase inhibition). Thus, the proposed grouping is unreasonably wide and the more detailed analyses show that structural similarity alone is not sufficient for grouping branched-chain carboxylic acids for developmental toxicity.
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Toxicology and carcinogenesis studies of di(2-ethylhexyl) phthalate administered in feed to Sprague Dawley (Hsd:Sprague Dawley SD) rats. NATIONAL TOXICOLOGY PROGRAM TECHNICAL REPORT SERIES 2021:NTP-TR-601. [PMID: 35073286 PMCID: PMC8996106 DOI: 10.22427/ntp-tr-601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Di(2-ethylhexyl) phthalate (DEHP) is a member of the phthalate ester chemical class that occurs commonly in the environment and to which humans are widely exposed. Lifetime exposure to DEHP is likely to occur, including during the in utero and early postnatal windows of development. To date, no carcinogenicity assessments of DEHP have used a lifetime exposure paradigm that includes the perinatal period (gestation and lactation). The National Toxicology Program (NTP) tested the hypothesis that exposure during the perinatal period would alter the DEHP carcinogenic response quantitatively (more neoplasms) or qualitatively (different neoplasm types). Two chronic carcinogenicity assessments of DEHP were conducted in which Sprague Dawley (Hsd:Sprague Dawley SD) rats were exposed to dosed feed containing 0, 300, 1,000, 3,000, or 10,000 ppm DEHP for 2 years using different exposure paradigms. In Study 1, groups of 45 F0 time-mated females were provided dosed feed beginning on gestation day (GD) 6 through lactation. On postnatal day (PND) 21, groups of 50 F1 rats per sex continued on the study and were provided dosed feed containing the same DEHP concentration as their respective dam for 2 years. In Study 2, groups of 50 rats per sex, aged 6 to 7 weeks at study start, were provided dosed feed containing DEHP for 2 years. (Abstract Abridged).
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Wu HF, Lu TY, Chu MC, Chen PS, Lee CW, Lin HC. Targeting the inhibition of fatty acid amide hydrolase ameliorate the endocannabinoid-mediated synaptic dysfunction in a valproic acid-induced rat model of Autism. Neuropharmacology 2020; 162:107736. [DOI: 10.1016/j.neuropharm.2019.107736] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 08/02/2019] [Accepted: 08/05/2019] [Indexed: 10/26/2022]
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Mennen RHG, Pennings JLAJ, Piersma AHA. Neural crest related gene transcript regulation by valproic acid analogues in the cardiac embryonic stem cell test. Reprod Toxicol 2019; 90:44-52. [PMID: 31445079 DOI: 10.1016/j.reprotox.2019.08.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/25/2019] [Accepted: 08/16/2019] [Indexed: 12/30/2022]
Abstract
In vivo, neural crest (NC) cells contribute critically to heart formation. The embryonic stem cells in the cardiac Embryonic Stem cell Test (ESTc) differentiate into a heterogeneous cell population including non-cardiomyocyte cells. The use of molecular biomarkers from different mechanistic pathways can refine quantitative embryotoxicity assessment. Gene expression levels representing different signalling pathways that could relate to beating cardiomyocyte formation were analysed at different time-points. Immunocytochemistry showed NC cells were present in the ESTc and RT-qPCR showed upregulation of NC related gene expression levels in a time-dependent manner. NC related genes were sensitive to VPA and its analogues 2-ethylhexanoic acid (EHA) and 2-ethylhexanol (EHOL) and indicated VPA as the most potent one. STITCH ('search tool for interactions of chemicals') analysis showed relationships between the examined signalling pathways and suggested additional candidate marker genes. Biomarkers from dedicated mechanistic pathways, e.g. NC differentiation, provide promising tools for monitoring specific effects in ESTc.
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Affiliation(s)
- R H Gina Mennen
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
| | - J L A Jeroen Pennings
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - A H Aldert Piersma
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands; Institute for Risk Assessment Sciences (IRAS), Utrecht University, the Netherlands
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5
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Wakayama T, Ito Y, Sakai K, Miyake M, Shibata E, Ohno H, Kamijima M. Comprehensive review of 2-ethyl-1-hexanol as an indoor air pollutant. J Occup Health 2019; 61:19-35. [PMID: 30698348 PMCID: PMC6499367 DOI: 10.1002/1348-9585.12017] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/02/2018] [Accepted: 10/10/2018] [Indexed: 11/12/2022] Open
Abstract
Objectives 2‐Ethyl‐1‐hexanol (2EH), a fragrance ingredient and a raw material for the production of plasticizer di(2‐ethylhexyl) phthalate, is responsible for sick building syndrome (SBS). This review aims to clarify the 2EH characteristics as an indoor air pollutant such as indoor air concentration, emission mechanism, toxicity, and clinical effects. Methods Scientific publications in English that has been made available on PubMed as of June 2018 and ad hoc publications in regional languages were reviewed. Results Inhalation exposure to 2EH caused mucous membrane irritation in the eyes, nose, and throat in experimental animals. Studies in human volunteers revealed an increase in olfactory irritation and eye discomfort. There has been increasing evidence of 2EH being present in indoor air in buildings. The primary sources of 2EH emissions are not building materials themselves, but instead the hydrolysis of plasticizers and flooring adhesives. In particular, compounds like di(2‐ethylhexyl) phthalate present in polyvinyl chloride flooring materials are hydrolyzed upon contact with alkaline moisture‐containing concrete floors. That being said, it may be observed that indoor concentrations of 2EH increased every year during summer. Conclusions Unlike other volatile organic compounds that cause SBS, 2EH can be retained in indoor air for long durations, increasing the likelihood of causing undesirable health effects in building occupants exposed to it. As a precautionary measure, it is important to use flooring materials that do not emit 2EH by hydrolysis, or to dry concrete before covering with flooring materials.
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Affiliation(s)
- Takanari Wakayama
- Department of Occupational and Environmental Health, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.,Department of Environmental Health, Nagoya City Public Health Research Institute, Nagoya, Japan
| | - Yuki Ito
- Department of Occupational and Environmental Health, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Kiyoshi Sakai
- Department of Occupational and Environmental Health, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.,Department of Environmental Health, Nagoya City Public Health Research Institute, Nagoya, Japan
| | - Mio Miyake
- Department of Occupational and Environmental Health, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Eiji Shibata
- Department of Health and Psychosocial Medicine, Aichi Medical University School of Medicine, Nagakute, Japan
| | - Hiroyuki Ohno
- Department of Environmental Health, Nagoya City Public Health Research Institute, Nagoya, Japan
| | - Michihiro Kamijima
- Department of Occupational and Environmental Health, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
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6
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de Leeuw VC, Hessel EVS, Piersma AH. Look-alikes may not act alike: Gene expression regulation and cell-type-specific responses of three valproic acid analogues in the neural embryonic stem cell test (ESTn). Toxicol Lett 2018; 303:28-37. [PMID: 30578912 DOI: 10.1016/j.toxlet.2018.12.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 12/07/2018] [Accepted: 12/13/2018] [Indexed: 12/20/2022]
Abstract
In vitro assays to assess developmental neurotoxicity of chemicals are highly desirable. The murine neural embryonic stem cell test (ESTn) can mimic parts of early differentiation of embryonic brain and may therefore be useful for this purpose. The aim of this study was to investigate whether this test is able to rank the toxic potencies of three valproic acid analogues and to study their mode of action by investigating their individual effects on four cell types: stem cells, neurons, astrocytes and neural crest cells. Using immunocytochemical read-outs and qPCR for cell type-specific genes, the effects of valproic acid (VPA), 2-ethylhexanoic acid (EHA) and 2-ethyl-4-methylpentanoic (EMPA) were assessed. VPA and EHA but not EMPA downregulated cell type-specific differentiation makers and upregulated stem cell related markers (Fut4, Cdh1) at different time points during differentiation. Expression of Gfap, a marker for astrocytes, was dramatically downregulated by VPA and EHA, but not by EMPA. This finding was verified using immunostainings. Based on the number and extent of genes regulated by the three compounds, relative potencies were determined as VPA > EHA > EMPA, which is consistent with in vivo developmental toxicity potency ranking of these compounds. Thus, ESTn using a combination of morphology, gene and protein expression readouts, may provide a medium-throughput system for monitoring the effects of compounds on differentiation of cell types in early brain development.
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Affiliation(s)
- Victoria C de Leeuw
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, the Netherlands.
| | - Ellen V S Hessel
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - Aldert H Piersma
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, the Netherlands
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7
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Zhu F, Zhu C, Doyle E, Liu H, Zhou D, Gao J. Fate of di (2‑ethylhexyl) phthalate in different soils and associated bacterial community changes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 637-638:460-469. [PMID: 29754081 DOI: 10.1016/j.scitotenv.2018.05.055] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/04/2018] [Accepted: 05/04/2018] [Indexed: 06/08/2023]
Abstract
Di (2‑ethylhexyl) phthalate (DEHP) is a ubiquitous organic pollutant, which has caused considerable pollution in arable soils. In this study, the relationship between DEHP degradation potential and soil properties in 12 agricultural soils (S1-S12) was examined in a microcosm based experiment. Six of these soils were then selected to monitor patterns in bacterial community responses. It was found that DEHP degradation was positively correlated with bacterial counts in the original soils, suggesting a key role for bacteria in degradation. However, DEHP metabolism did not always lead to complete degradation. Its monoester metabolite, mono (2‑ethylhexyl) phthalate (MEHP), was present at appreciable levels in the two acidic soils (S1 and S2) during the incubation period of 35 days. Based on high-throughput sequencing data, we observed a greater impact of DEHP contamination on bacterial community structure in acidic soils than in the other soils. Nocardioides, Ramlibacter and unclassified Sphingomonadaceae were enriched in the two near-neutral soils where degradation was highest (S4 and S7), suggesting that these organisms might be efficient degraders. The relative abundance of Tumibacillus was greatly reduced in 50% of the six soils examined, demonstrating a high sensitivity to DEHP contamination. Furthermore, putative organic-matter decomposing bacteria (including Tumebacillus and other bacteria taxa such as members from Micromonosporaceae) were greatly reduced in the two acidic soils (S1 and S2), possibly due to the accumulation of MEHP. These results suggest a crucial role of soil acidity in determining the fate and impact of DEHP in soil ecosystems, which deserves further investigation. This work contributes to a better understanding of the environmental behavior of DEHP in soil and should facilitate the development of appropriate remediation technologies.
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Affiliation(s)
- Fengxiao Zhu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Changyin Zhu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Evelyn Doyle
- Environmental Microbiology Group, School of Biology and Environmental Science and Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Hailong Liu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Dongmei Zhou
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Juan Gao
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China.
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Fennell TR, Mathews JM, Snyder RW, Hong Y, Watson SL, Black SR, McIntyre BS, Waidyanatha S. Metabolism and disposition of 2-ethylhexyl-p-methoxycinnamate following oral gavage and dermal exposure in Harlan Sprague Dawley rats and B6C3F1/N mice and in hepatocytes in vitro. Xenobiotica 2017; 48:1142-1156. [PMID: 29111853 DOI: 10.1080/00498254.2017.1400129] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
1. 2-Ethylhexyl-p-methoxycinnamate (EHMC) is commonly used as an ingredient in sunscreens, resulting in potential oral and dermal exposure in humans. 2. Clearance and metabolism of EHMC in hepatocytes and disposition and metabolism of EHMC in rodents following oral (8-800 mg/kg) intravenous (IV) (8 mg/kg) or dermal (0.8-80 mg/kg representing 0.1-10% formulation concentration) exposure to [14C]EHMC were investigated in rats and mice. 3. EHMC was rapidly cleared from rat and mouse hepatocytes (half-life ≤3.16 min) and less rapidly (half-life ≤48 min) from human hepatocytes. 4. [14C]EHMC was extensively absorbed and excreted primarily in urine by 72 h after oral administration to rats (65-80%) and mice (63-72%). Oral doses to rats were excreted to a lesser extent (3-8%) in feces and as CO2 (1-4%). Radioactive residues in tissues were <1% of the dose. There were no sex or species differences in disposition in rats. 5. Following dermal application, 34-42% of an 8-mg/kg dose was absorbed in rats, and 54-62% in mice in 72-h. 6. Among numerous urinary metabolites associated with hydrolysis of the ester, two potential reproductive and developmental toxicants, 2-ethylhexanol and 2-ethylhexanoic acid were produced by metabolism of EHMC.
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Affiliation(s)
- Timothy R Fennell
- a Discovery Sciences, RTI International , Research Triangle Park , NC , USA and
| | - James M Mathews
- a Discovery Sciences, RTI International , Research Triangle Park , NC , USA and
| | - Rodney W Snyder
- a Discovery Sciences, RTI International , Research Triangle Park , NC , USA and
| | - Yan Hong
- a Discovery Sciences, RTI International , Research Triangle Park , NC , USA and
| | - Scott L Watson
- a Discovery Sciences, RTI International , Research Triangle Park , NC , USA and
| | - Sherry R Black
- a Discovery Sciences, RTI International , Research Triangle Park , NC , USA and
| | - Barry S McIntyre
- b Division of the National Toxicology Program, National Institute of Environmental Health Sciences , Durham , NC , USA
| | - Suramya Waidyanatha
- b Division of the National Toxicology Program, National Institute of Environmental Health Sciences , Durham , NC , USA
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9
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Read-across of 90-day rat oral repeated-dose toxicity: A case study for selected 2-alkyl-1-alkanols. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.comtox.2017.02.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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RIFM fragrance ingredient safety assessment, 2-ethyl-1-butanol, CAS Registry Number 97-95-0. Food Chem Toxicol 2016; 97S:S157-S167. [PMID: 27658323 DOI: 10.1016/j.fct.2016.09.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 09/16/2016] [Indexed: 11/23/2022]
Abstract
The use of this material under current conditions is supported by existing information. This material was evaluated for genotoxicity, repeated dose toxicity, developmental and reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, as well as environmental safety. Data from the suitable read across analog 2-ethylhexanol (CAS # 104-76-7) show that this material is not genotoxic. Data from the suitable read across analog isopropyl alcohol (CAS # 67-63-0) show that this material does not have skin sensitization potential. The local respiratory toxicity endpoint was completed using the TTC (Threshold of Toxicological Concern) for a Cramer Class I material (1.4 mg/day). The repeated dose toxicity endpoint was completed using 2-ethylhexanol (CAS # 104-76-7) and 1-heptanol, 2-propyl (CAS # 10042-59-8) as suitable read across analogs, which provided a MOE > 100. The developmental and reproductive toxicity endpoint was completed using 2-ethyl-hexanol (CAS # 104-76-7) and isobutyl alcohol (CAS # 78-83-1) as suitable read across analogs, which provided a MOE > 100. The phototoxicity/photoallergenicity endpoint was completed based on suitable UV spectra. The environmental endpoint was completed as described in the RIFM Framework.
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Api AM, Belsito D, Bhatia S, Bruze M, Calow P, Dagli ML, Dekant W, Fryer AD, Kromidas L, La Cava S, Lalko JF, Lapczynski A, Liebler DC, Penning TM, Politano VT, Ritacco G, Salvito D, Schultz TW, Shen J, Sipes IG, Wall B, Wilcox DK. RIFM fragrance ingredient safety assessment, 2-ethyl-1-hexanol, CAS registry number 104-76-7. Food Chem Toxicol 2016; 97S:S147-S156. [PMID: 27600295 DOI: 10.1016/j.fct.2016.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 08/30/2016] [Accepted: 09/01/2016] [Indexed: 11/26/2022]
Abstract
The use of this material under current conditions is supported by existing information. This material was evaluated for genotoxicity, repeated dose toxicity, developmental toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity, skin sensitization, as well as environmental safety. Data show that this material is not genotoxic. Data from the suitable read across analog 2-butyloctan-1-ol (CAS # 3913-02-8) show that this material does not have skin sensitization potential. The reproductive and local respiratory toxicity endpoints were completed using the TTC (Threshold of Toxicological Concern) for a Cramer Class I material (0.03 and 1.4 mg/day, respectively). The developmental and repeat dose toxicity endpoints were completed data on the target material which provided a MOE > 100. The phototoxicity/photoallergenicity endpoint was completed based on suitable UV spectra. The environmental endpoint was completed as described in the RIFM Framework.
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Affiliation(s)
- A M Api
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA.
| | - D Belsito
- Member RIFM Expert Panel, Columbia University Medical Center, Department of Dermatology, 161 Fort Washington Ave., New York, NY, 10032, USA
| | - S Bhatia
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - M Bruze
- Member RIFM Expert Panel, Malmo University Hospital, Department of Occupational & Environmental Dermatology, Sodra Forstadsgatan 101, Entrance 47, Malmo, SE-20502, Sweden
| | - P Calow
- Member RIFM Expert Panel, Humphrey School of Public Affairs, University of Minnesota, 301 19th Avenue South, Minneapolis, MN, 55455, USA
| | - M L Dagli
- Member RIFM Expert Panel, University of Sao Paulo, School of Veterinary Medicine and Animal Science, Department of Pathology, Av. Prof. dr. Orlando Marques de Paiva, 87, Sao Paulo, CEP 05508-900, Brazil
| | - W Dekant
- Member RIFM Expert Panel, University of Wuerzburg, Department of Toxicology, Versbacher Str. 9, 97078, Würzburg, Germany
| | - A D Fryer
- Member RIFM Expert Panel, Oregon Health Science University, 3181 SW Sam Jackson Park Rd., Portland, OR, 97239, USA
| | - L Kromidas
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - S La Cava
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - J F Lalko
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - A Lapczynski
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - D C Liebler
- Member RIFM Expert Panel, Vanderbilt University School of Medicine, Department of Biochemistry, Center in Molecular Toxicology, 638 Robinson Research Building, 2200 Pierce Avenue, Nashville, TN, 37232-0146, USA
| | - T M Penning
- Member of RIFM Expert Panel, University of Pennsylvania, Perelman School of Medicine, Center of Excellence in Environmental Toxicology, 1316 Biomedical Research Building (BRB) II/III, 421 Curie Boulevard, Philadelphia, PA, 19104-3083, USA
| | - V T Politano
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - G Ritacco
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - D Salvito
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - T W Schultz
- Member RIFM Expert Panel, The University of Tennessee, College of Veterinary Medicine, Department of Comparative Medicine, 2407 River Dr., Knoxville, TN, 37996-4500, USA
| | - J Shen
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - I G Sipes
- Member RIFM Expert Panel, Department of Pharmacology, University of Arizona, College of Medicine, 1501 North Campbell Avenue, P.O. Box 245050, Tucson, AZ, 85724-5050, USA
| | - B Wall
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - D K Wilcox
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
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Nelson BK, Brightwell WS, Khan A, Krieg EF, Hoberman AM. Developmental Toxicology Evaluation of 1-Pentanol, 1-Hexanol, and 2-Ethyl-1-Hexanol Administered by Inhalation to Rats. ACTA ACUST UNITED AC 2016. [DOI: 10.3109/10915818909019562] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
As part of a large study evaluating the developmental toxicology of industrial alcohols, groups of approximately 15 Sprague-Dawley rats were exposed for 7 h/day on gestation days 1–19 to one of three alcohols at the highest concentrations we could generate as a vapor. Since these concentrations were not sufficiently high to be toxic to the maternal rats, lower levels were not included. These concentrations were 14,000, 3500, and 850 mg/m3 1-pentanol, 1-hexanol, and 2-ethyl-1-hexanol, respectively. Dams were weighed daily for the first week of exposure and weekly thereafter and were sacrificed on day 20. Fetuses were serially removed, blotted dry, examined for external malformations, sexed, weighed, fixed, and examined for visceral or skeletal defects. Pentanol reduced maternal feed intake and weight gain, but there were no significant decreases in fetal weights. Resorptions were slightly increased in the group exposed to 1-hexanol, and 2-ethyl-1-hexanol reduced maternal feed intake, but neither hexanol derivative produced malformations. Obviously, teratogenicity by other routes of exposure cannot be ruled out, particularly in view of the low volatility of these alcohols. However, the present studies indicate that inhalation of pentanol, hexanol, or 2-ethyl-1-hexanol at the stated concentrations can produce limited maternal toxicity, but none was teratogenic to rats.
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Affiliation(s)
- B. K. Nelson
- Division of Biomedical and Behavioral Science NIOSH C-24 4676 Columbia Parkway Cincinnati, OH 45226–1998
| | - W. S. Brightwell
- Division of Biomedical and Behavioral Science NIOSH C-24 4676 Columbia Parkway Cincinnati, OH 45226–1998
| | - A. Khan
- Division of Biomedical and Behavioral Science NIOSH C-24 4676 Columbia Parkway Cincinnati, OH 45226–1998
| | - E. F. Krieg
- Division of Biomedical and Behavioral Science NIOSH C-24 4676 Columbia Parkway Cincinnati, OH 45226–1998
| | - A. M. Hoberman
- Division of Biomedical and Behavioral Science NIOSH C-24 4676 Columbia Parkway Cincinnati, OH 45226–1998
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Wu HF, Chen PS, Chen YJ, Lee CW, Chen IT, Lin HC. Alleviation of N-Methyl-D-Aspartate Receptor-Dependent Long-Term Depression via Regulation of the Glycogen Synthase Kinase-3β Pathway in the Amygdala of a Valproic Acid-Induced Animal Model of Autism. Mol Neurobiol 2016; 54:5264-5276. [PMID: 27578017 DOI: 10.1007/s12035-016-0074-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/18/2016] [Indexed: 12/18/2022]
Abstract
The amygdala plays crucial roles in socio-emotional behavior and cognition, both of which are abnormal in autism spectrum disorder (ASD). Valproic acid (VPA)-exposed rat offspring have demonstrated ASD phenotypes and amygdala excitatory/inhibitory imbalance. However, the role of glutamatergic synapses in this imbalance remains unclear. In this study, we used a VPA-induced ASD-like model to assess glutamatergic synapse-dependent long-term depression (LTD) and depotentiation (DPT) in the amygdala. We first confirmed that the VPA-exposed offspring exhibited sociability deficits, anxiety, depression-like behavior, and abnormal nociception thresholds. Then, electrophysiological examination showed a significantly decreased paired-pulse ratio in the amygdala. In addition, both NMDA-dependent LTD and DPT were absent from the amygdala. Furthermore, we found that the levels of glycogen synthase kinase3β (GSK-3β) phosphorylation and β-catenin were significantly higher in the amygdala of the experimental animals than in the controls. Local infusion of phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin into the amygdala reversed the increased phosphorylation level and impaired social behavior. Taken together, the results suggested that NMDA receptor-related synaptic plasticity is dysfunctional in VPA-exposed offspring. In addition, GSK-3β in the amygdala is critical for synaptic plasticity at the glutamatergic synapses and is related to social behavior. Its role in the underlying mechanism of ASD merits further investigation.
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Affiliation(s)
- Han-Fang Wu
- Department and Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Po See Chen
- Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Addiction Research Center, National Cheng Kung University, Tainan, Taiwan
| | - Yi-Ju Chen
- Department and Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Chi-Wei Lee
- Department and Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan
| | - I-Tuan Chen
- Department and Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Hui-Ching Lin
- Department and Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan. .,Brain Research Center, National Yang-Ming University, Taipei, 11221, Taiwan. .,Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, 11031, Taiwan.
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Abstract
Caffeine is a drug that is a common ingredient of popular foods, beverages, and over-the-counter as well as prescription medications. While at least 30% of Americans consume a moderate amount (200 mg. a day, about two cups of coffee), many others function with a much higher intake, 600 mg. or more (six or more cups of coffee). Researchers are discovering that caffeine may not be as safe as many people believe, since the substance has widespread effects on many body systems. It has also been linked to a variety of ailments, among them anxiety and hypertension, although information linking caffeine to cancer and birth defects is still speculative. In light of the expanding body of knowledge on the deleterious effects of caffeine, individuals should moderate or eliminate their intake of major caffeine-containing foods, beverages, and drugs. Health promotion programs can assist in this goal by providing education and support.
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16
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Api AM, Belsito D, Bhatia S, Bruze M, Calow P, Dagli ML, Dekant W, Fryer AD, Kromidas L, La Cava S, Lalko JF, Lapczynski A, Liebler DC, Penning TM, Politano VT, Ritacco G, Salvito D, Schultz TW, Shen J, Sipes IG, Wall B, Wilcox DK. RIFM fragrance ingredient safety assessment, 2-methylundecanol, CAS Registry Number 10522-26-6. Food Chem Toxicol 2016; 97S:S119-S128. [PMID: 27475044 DOI: 10.1016/j.fct.2016.07.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 07/25/2016] [Indexed: 10/21/2022]
Abstract
This material was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, as well as environmental safety. Data from the suitable read across analogs 2-butyloctan-1-ol (CAS # 3913-02-8) and 2-ethyl-1-hexanol (CAS # 104-76-7) show that this material is not genotoxic nor does it have skin sensitization potential. The reproductive and local respiratory toxicity endpoints were completed using the TTC (Threshold of Toxicological Concern) for a Cramer Class I material (0.03 and 1.4 mg/day, respectively). The repeated dose toxicity endpoint was completed using 2-ethyl-1-hexanol (CAS # 104-76-7) and 1-heptanol, 2-propyl (CAS # 10042-59-8) as suitable read across analogs, which provided a MOE > 100. The developmental toxicity endpoint was completed using 2-ethyl-1-hexanol (CAS # 104-76-7) as a suitable read across analog, which provided a MOE > 100 The phototoxicity/photoallergenicity endpoint was completed based on suitable UV spectra. The environmental endpoint was completed as described in the RIFM Framework.
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Affiliation(s)
- A M Api
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA.
| | - D Belsito
- Columbia University Medical Center, Department of Dermatology, 161 Fort Washington Ave., New York, NY, 10032, USA
| | - S Bhatia
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - M Bruze
- Malmo University Hospital, Department of Occupational & Environmental Dermatology, Sodra Forstadsgatan 101, Entrance 47, Malmo, SE-20502, Sweden
| | - P Calow
- Humphrey School of Public Affairs, University of Minnesota, 301 19th Avenue South, Minneapolis, MN, 55455, USA
| | - M L Dagli
- University of Sao Paulo, School of Veterinary Medicine and Animal Science, Department of Pathology, Av. Prof. dr. Orlando Marques de Paiva, 87, Sao Paulo, CEP 05508-900, Brazil
| | - W Dekant
- University of Wuerzburg, Department of Toxicology, Versbacher Str. 9, 97078, Würzburg, Germany
| | - A D Fryer
- Oregon Health Science University, 3181 SW Sam Jackson Park Rd., Portland, OR, 97239, USA
| | - L Kromidas
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - S La Cava
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - J F Lalko
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - A Lapczynski
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - D C Liebler
- Vanderbilt University School of Medicine, Department of Biochemistry, Center in Molecular Toxicology, 638 Robinson Research Building, 2200 Pierce Avenue, Nashville, TN, 37232-0146, USA
| | - T M Penning
- University of Pennsylvania, Perelman School of Medicine, Center of Excellence in Environmental Toxicology, 1316 Biomedical Research Building (BRB) II/III, 421 Curie Boulevard, Philadelphia, PA, 19104-3083, USA
| | - V T Politano
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - G Ritacco
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - D Salvito
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - T W Schultz
- The University of Tennessee, College of Veterinary Medicine, Department of Comparative Medicine, 2407 River Dr., Knoxville, TN, 37996- 4500, USA
| | - J Shen
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - I G Sipes
- Department of Pharmacology, University of Arizona, College of Medicine, 1501 North Campbell Avenue, P.O. Box 245050, Tucson, AZ, 85724-5050, USA
| | - B Wall
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - D K Wilcox
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
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17
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Burdan F. Developmental effects of propyphenazone in analgesic and antipyretic combination with caffeine or paracetamol. Hum Exp Toxicol 2016; 23:235-44. [PMID: 15222401 DOI: 10.1191/0960327104ht439oa] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The aim of the study was to determine the influence of an over-the-counter (OTC) mixture of propyphenazone with caffeine or paracetamol on prenatal development. Propyphenazone:caffeine and propyphenazone:paracetamol mixtures were prepared with constant 3:1 and 3:5 ratios, respectively. Three dose levels of each of the mixtures were administered separately in Tween-80 water suspension once a day to pregnant Wistar rats on gestation days 8-14. The low dose was similar to the OTC preparations, 2.1 mg/kg of propyphenazone, 0.7 mg/kg of caffeine or 3.5 mg/kg of paracetamol. The middle dose was 21.0, 7.0 or 35.0 mg/kg, and the highest 210.0, 70.0 or 350.0 mg/kg for propyphenazone, caffeine or paracetamol, respectively. On day 21 of gestation the fetuses were delivered by hysterectomy. Dead or live fetuses, resorptions and the number of implantation sites were counted. Live fetuses were examined for external, visceral and skeletal malformation. Postimplantation mortality was calculated. Dose-dependent effects in the middle and high dose groups on fetal body weight/length and placental weight were found. No increase in external or internal congenital anomalies was found in any of the mixture-exposed groups. Prenatal coadministration of propyphenazone with caffeine or paracetamol caused intrauterine growth retardation but did not increase external or internal congenital anomalies. The risk of midline defects (umbilical hernia and gastroschisis) is discussed.
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Affiliation(s)
- F Burdan
- Experimental Teratology Unit of the Human Anatomy Department, Medical University of Lublin, PL-20074 Lublin, Poland.
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18
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19
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Fiume M, Heldreth B, Bergfeld WF, Belsito DV, Hill RA, Klaassen CD, Liebler DC, Marks JG, Shank RC, Slaga TJ, Snyder PW, Andersen FA. Safety Assessment of Alkyl Ethylhexanoates as Used in Cosmetics. Int J Toxicol 2015; 34:61S-73S. [PMID: 26684798 DOI: 10.1177/1091581815617794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) assessed the safety of 16 alkyl ethylhexanoates for use in cosmetics, concluding that these ingredients are safe in cosmetic formulations in the present practices of use and concentrations when formulated to be nonirritating. The alkyl ethylhexanoates primarily function as skin-conditioning agents in cosmetics. The highest concentration of use reported for any of the alkyl ethylhexanoates is 77.3% cetyl ethylhexanoate in rinse-off formulations used near the eye, and the highest leave-on use reported is 52% cetyl ethylhexanoate in lipstick formulations. The Panel reviewed available animal and clinical data related to these ingredients, and the similarities in structure, properties, functions, and uses of ingredients from previous CIR assessments on constituent alcohols that allowed for extrapolation of the available toxicological data to assess the safety of the entire group.
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Affiliation(s)
- Monice Fiume
- Cosmetic Ingredient Review Senior Scientific Analyst/Writer, Washington, DC, USA
| | - Bart Heldreth
- Cosmetic Ingredient Review Chemist, Washington, DC, USA
| | - Wilma F Bergfeld
- Cosmetic Ingredient Review Expert Panel Member, Washington, DC, USA
| | - Donald V Belsito
- Cosmetic Ingredient Review Expert Panel Member, Washington, DC, USA
| | - Ronald A Hill
- Cosmetic Ingredient Review Expert Panel Member, Washington, DC, USA
| | | | - Daniel C Liebler
- Cosmetic Ingredient Review Expert Panel Member, Washington, DC, USA
| | - James G Marks
- Cosmetic Ingredient Review Expert Panel Member, Washington, DC, USA
| | - Ronald C Shank
- Cosmetic Ingredient Review Expert Panel Member, Washington, DC, USA
| | - Thomas J Slaga
- Cosmetic Ingredient Review Expert Panel Member, Washington, DC, USA
| | - Paul W Snyder
- Cosmetic Ingredient Review Expert Panel Member, Washington, DC, USA
| | - F Alan Andersen
- Former Director, Cosmetic Ingredient Review, Washington, DC, USA
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20
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Venters SJ, Ordahl CP. Somite unit chronometry to analyze teratogen phase specificity in the paraxial mesoderm. Methods Mol Biol 2012; 798:103-123. [PMID: 22130834 DOI: 10.1007/978-1-61779-343-1_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Phase specificity, the temporal and tissue restriction of teratogen-induced defects during embryonic -development, is a poorly understood but common property of teratogens, an important source of human birth defects. Somite counting and somite units are novel chronometric tools used here to identify stages of paraxial mesoderm development that are sensitive to pulse-chase exposure (2 to >16 h) to 5-bromodeoxyuridine (BrdU). In all cases, it was the presomitic mesoderm (PSM) that was sensitive to BrdU induced segmentation anomalies. At high concentration (1.0 × 10(-2) M BrdU), PSM presegment stages ss-IV and earlier were irreversibly inhibited from completing segmentation. At low concentration (2.6 × 10(-6) M), BrdU induced periodic focal defects that predominantly trace back to PSM presegments between ss-V and ss-IX. Phase specificity is characteristic of both types of segmentation anomalies. Focal segmentation defects are phase-specific because they result from disruption of 2-3 presegments in the PSM while adjacent -rostral and caudal presegments are (apparently) unaffected. Irreversible inhibition of segmentation is also phase-specific because only PSM presegments ss-IV or earlier were affected while older segments (ss-III to ss-I) were able to complete segmentation. The presegments predominantly affected have not yet passed the determination front, the point at which the segmentation clock establishes somite rostro-caudal -polarity. Somite unit chronometry provides a means to identify specific PSM presegment stages that are susceptible to induced segmentation defects and the biological processes that underlie that vulnerability.
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Affiliation(s)
- Sara J Venters
- Department of Neurosurgery, School of Medicine, University of California, San Francisco, CA, USA
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21
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Abstract
A summary of the safety data available for 2-ethyl-1-hexanol when used as a fragrance ingredient is presented. 2-Ethyl-1-hexanol is a member of the fragrance structural group branched chain saturated alcohols in which the common characteristic structural element is one hydroxyl group per molecule, and a C(4) to C(12) carbon chain with one or several methyl side chains. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. A safety assessment of the entire branched chain saturated alcohol group will be published simultaneously with this document; please refer to Belsito et al. (2010) for an overall assessment of the safe use of this material and all other branched chain saturated alcohols in fragrances.
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22
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Belsito D, Bickers D, Bruze M, Calow P, Greim H, Hanifin JM, Rogers AE, Saurat JH, Sipes IG, Tagami H. A safety assessment of branched chain saturated alcohols when used as fragrance ingredients. Food Chem Toxicol 2010; 48 Suppl 4:S1-46. [PMID: 20659630 DOI: 10.1016/j.fct.2010.05.046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The Branched Chain Saturated Alcohol (BCSA) group of fragrance ingredients was evaluated for safety. In humans, no evidence of skin irritation was found at concentrations of 2-10%. Undiluted, 11 materials evaluated caused moderate to severe eye irritation. As current end product use levels are between 0.001% and 1.7%, eye irritation is not a concern. The materials have no or low sensitizing potential. For individuals who are already sensitized, an elicitation reaction is possible. Due to lack of UVA/UVB light-absorbing structures, and review of phototoxic/photoallergy data, the BCSA are not expected to elicit phototoxicity or photoallergy. The 15 materials tested have a low order of acute toxicity. Following repeated application, seven BCSA tested were of low systemic toxicity. Studies performed on eight BCSA and three metabolites show no in vivo or in vitro genotoxicity. A valid carcinogenicity study showed that 2-ethyl-1-hexanol is a weak inducer of liver tumors in female mice, however, the relevance of this effect and mode of action to humans is still a matter of debate. The Panel is of the opinion that there are no safety concerns regarding BCSA under the present levels of use and exposure.
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Affiliation(s)
- D Belsito
- University of Missouri (Kansas City), c/o American Dermatology Associates, LLC, 6333 Long Avenue, Third Floor, Shawnee, KS 66216, USA
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23
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Flavouring Group Evaluation 04 −2-Ethylhexyl derivatives from chemical group 2 - Scientific Opinion of the Panel on Food Additives, Flavourings, Processing Aids and Materials in contact with Food (AFC). EFSA J 2009. [DOI: 10.2903/j.efsa.2009.929] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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24
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Schripp T, Nachtwey B, Toelke J, Salthammer T, Uhde E, Wensing M, Bahadir M. A microscale device for measuring emissions from materials for indoor use. Anal Bioanal Chem 2007; 387:1907-19. [PMID: 17225110 DOI: 10.1007/s00216-006-1057-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Revised: 11/24/2006] [Accepted: 11/28/2006] [Indexed: 10/23/2022]
Abstract
Emission test chambers or cells are used to determine organic vapour emissions from construction products under controlled conditions. Polymeric car trim component emissions are typically evaluated using direct thermal desorption/extraction. The Microchamber/Thermal Extractor (mu-CTE, Markes International) was developed to provide both a complementary tool for rapid screening of volatile organic compound (VOC) emissions--suitable for industrial quality control--and a means for thermal extraction of larger, more representative samples of car trim components. To determine the degree of correlation between conventional emission test methods and the microchamber, experiments were carried out under different conditions of temperature, air change rate and sample conditioning time. Good quantitative and qualitative correlation was obtained for measurements at ambient temperature. Moreover, it was shown that ambient-temperature emissions data collected using the mu-CTE as rapidly as possible--i.e. with minimal or no sample conditioning time--nevertheless provided a reliable guide as to how well that material would perform in subsequent 3-day chamber tests of VOC emissions. The parameters found to have the greatest influence on data correlation for experiments carried out at elevated temperatures were the sample mass (for bulk emissions testing) and the conditioning time. The results also showed that, within the constraints of inherent sample homogeneity, the mu-CTE gave reproducible emissions data, despite its small sample size/capacity relative to that of conventional chambers. Preliminary results of modelling the air flow within a microchamber using computational fluid dynamics showed a high degree of turbulent flow and two potential areas of still air which could cause sink effects. However, the experimental data reported here and in previous studies showed enhanced recovery of semivolatile components from the mu-CTE relative to a recovery from a 1 m(3) conventional chamber. This indicates that if these areas of relatively still air are present within the microchamber, they do not appear to be significant in practice.
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Affiliation(s)
- T Schripp
- Fraunhofer Wilhelm-Klauditz-Institute (WKI), Material Analysis and Indoor Chemistry, Bienroder Weg 54E, 38108 Braunschweig, Germany
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25
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Fabjan E, Hulzebos E, Mennes W, Piersma AH. A category approach for reproductive effects of phthalates. Crit Rev Toxicol 2006; 36:695-726. [PMID: 17050082 DOI: 10.1080/10408440600894914] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
In regulatory toxicology, the experimental assessment of reproductive toxicity is one of the most costly endpoints to perform. Categorizing chemicals is an approach that can be used to reduce animal tests in risk assessments of chemicals, for example, via REACH (Registration, Evaluation, and Authorization of Chemicals). The category approach was tested for reproductive toxicity with a group of 10 ortho-phthalate esters, with different side chain lengths. Three ortho-phthalates were used for testing the category. Phthalates with side-chain lengths C4 to C6 that are commonly known to cause reproductive effects were included, as well as the recently discovered mechanism that indicates antiandrogenic effects. The differences in physicochemical properties, absorption rates, and metabolism between the phthalates investigated could not fully explain the difference in reproductive toxicity. It was concluded that phthalates with the alkyl side-chain length from C4 to C6 produce similar severe reproductive effects in experimental animals. It is expected that phthalates included in the tight boundaries of the proposed category would all show severe reproductive effects, especially the antiandrogenic effects. Further testing might not be needed for phthalates within these boundaries. If necessary, limited testing could focus on the critical endpoints. Detailed mechanistic information is needed on phthalates to apply the categories for regulatory toxicology.
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Affiliation(s)
- Evelin Fabjan
- Utrecht University, Institute for Risk Assessment Sciences, Utrecht, The Netherlands
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26
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Lee J, Park J, Jang B, Knudsen TB. Altered expression of genes related to zinc homeostasis in early mouse embryos exposed to di-2-ethylhexyl phthalate. Toxicol Lett 2004; 152:1-10. [PMID: 15294341 DOI: 10.1016/j.toxlet.2004.03.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2003] [Revised: 03/04/2004] [Accepted: 03/08/2004] [Indexed: 11/21/2022]
Abstract
Numerous studies have shown that di-2-ethylhexyl phthalate (DEHP) is teratogenic in animals but the mechanism of developmental toxicity is not well understood. One hypothesis is altered zinc homeostasis. The present study has investigated the effect of DEHP exposure on several key genes in zinc metabolism (MT-I, MT-II, ZnT-1) for early mouse embryos exposed in utero. Time- and dose-dependent effects were examined using expression polymerase chain reaction (PCR) (relative to ACTB) and Western blot analysis of the maternal liver, embryonic brain, and visceral yolk sac at 9 days post-coitus (d.p.c.). Maternal exposure to 800 mg/kg DEHP increased the abundance of MT-I and MT-II transcripts in maternal liver at 3.0, 4.5 and 6.0 h after administration. MT-I and MT-II protein induction was confirmed by Western blot analysis. On the other hand, this exposure down-regulated both transcripts (MT-I, MT-II), as well as transcripts for a zinc transporter (ZnT-1), in the embryonic brain, but not the visceral yolk sac. To examine dose-response relationships, the experiment was repeated for DEHP exposures of 50, 200 and 800 mg/kg. The effect to MT-I and MT-II expression in the maternal liver became significant at the 200 mg/kg dose level. The contrasting effect to MT-I, MT-II and ZnT-1 expression in the embryo was also dose-dependent, and a benchmark computation for the dose resulting in a 5% change in the mean (BMD5) was estimated as 11.6 mg/kg for MT-I, 8.9 mg/kg for MT-II, and 6.6 mg/kg for ZnT-1. We conclude that DEHP exposure to pregnant dams at reasonably low levels during organogenesis stages can alter the expression of several key genes in embryonic zinc homeostasis.
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Affiliation(s)
- Jongwha Lee
- Department of Environmental Health Science, Soonchunhyang University, Choongchungnam-do, Asan-si, Republic of Korea.
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27
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Elss S, Grünewald L, Richling E, Schreier P. Occurrence of 2-ethylhexanoic acid in foods packed in glass jars. ACTA ACUST UNITED AC 2004; 21:811-4. [PMID: 15370833 DOI: 10.1080/02652030410001732879] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
After simultaneous distillation-extraction (SDE) of commercial baby foods (n = 20) and fruit juices (n = 15) (among them 15 and eight products labelled 'organic', respectively) from 11 different suppliers, analyses performed by coupled capillary gas chromatography-mass spectrometry (GC-MS) revealed the presence of 2-ethylhexanoic acid (2-EHA), a known teratogenic compound. 2-EHA was found in 80 and 73% of the baby foods and fruit juices, respectively. Amounts ranged from 0.25 to 3.2 mg kg(-1)(average, 0.55 mg kg(-1)) and from 0.01 to 0.59 mg l(-1) (average, 0.18 mg l(-1)) in baby foods and fruit juices, respectively. GC-MS analysis of the SDE extracts obtained from the plastic gaskets inside the metal lids of the samples under study revealed the gaskets to be the origin of 2-EHA. As shown from the non-contaminated samples under study, obviously technology is available to avoid 2-EHA contamination of glass jar-packed food.
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Affiliation(s)
- S Elss
- Universität Würzburg, Würzburg, Germany
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28
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Lampen A, Zimnik S, Nau H. Teratogenic phthalate esters and metabolites activate the nuclear receptors PPARs and induce differentiation of F9 cells. Toxicol Appl Pharmacol 2003; 188:14-23. [PMID: 12668118 DOI: 10.1016/s0041-008x(03)00014-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Industrial plasticizers such as phthalates can induce peroxisome proliferation. Some phthalates such as di-2-ethyl-hexyl-phthalate (DEHP) and its metabolites mono-2-ethyl-hexyl-phthalate and 2-ethyl-hexanoic acid are also known teratogens. Recently, we introduced two in vitro test systems consisting of F9 teratocarcinoma cell differentiation and activation of peroxisome proliferator-activated receptor (PPAR)-ligand-binding domain in Chinese hamster ovary-reporter cells for the detection of teratogenic compounds related to the antiepileptic drug valproic acid. We now applied these methods to the class of phthalate esters and their metabolites by testing 2 diphthalate esters and 19 monophthalate esters in vitro. In the F9 cell assay only five compounds, mono-2-ethyl-hexyl-phthalate, mono-1-methyl-heptyl-phthalate, mono-benzyl-phthalate, benzyl-butyl-phthalate, and 2-ethyl-hexanoic acid were found to induce F9 cell differentiation. The other test compounds were not able to induce differentiation of F9 cells. Three compounds (mono-methyl-phthalate, mono-ethyl-phthalate, and mono-2,2-dimethyl-1-phenyl-propyl-phthalate, and phthalic acid di-methyl-ester were found not to interact with any PPARs. All other phthalate esters activated PPARs. Most compounds activated PPARalpha and PPARgamma. Interestingly PPARgamma in most cases was activated stronger than PPARalpha. Only the five test compounds, mono-2-ethyl-hexyl-phthatate, mono-1-methyl-heptyl-phthalate, mono-benzyl-phthalate, benzyl-butyl-phthalate, and 2-ethyl-hexanoic acid activated PPARdelta and interacted with a specific PPARdelta-response element. These are the same compounds that induced F9 cell differentiation and three of them are known teratogenic compounds. It is concluded that phthatate esters are acting like hormones by activating PPARs. The combination of F9 cell differentiation assay and PPARdelta activation assay detected possible teratogenic phthalate-ester and derivatives. Therefore the test systems seem useful for a screening test system in the early development of new plasticizers.
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Affiliation(s)
- Alfonso Lampen
- Zentrumsabteilung für Lebensmitteltoxikologie, Tierärztliche Hochschule Hannover, D-30173 Hannover, Germany.
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Kavlock R, Boekelheide K, Chapin R, Cunningham M, Faustman E, Foster P, Golub M, Henderson R, Hinberg I, Little R, Seed J, Shea K, Tabacova S, Tyl R, Williams P, Zacharewski T. NTP Center for the Evaluation of Risks to Human Reproduction: phthalates expert panel report on the reproductive and developmental toxicity of di(2-ethylhexyl) phthalate. Reprod Toxicol 2002; 16:529-653. [PMID: 12406494 DOI: 10.1016/s0890-6238(02)00032-1] [Citation(s) in RCA: 271] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Robert Kavlock
- National Health and Environmental Effects Research Laboratory, USEPA, Research Triangle Park, NC, USA
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30
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Christian MS, Brent RL. Teratogen update: evaluation of the reproductive and developmental risks of caffeine. TERATOLOGY 2001; 64:51-78. [PMID: 11410911 DOI: 10.1002/tera.1047] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Caffeine is a methylated xanthine that acts as a mild central nervous system stimulant. It is present in many beverages, including coffee, tea, and colas, as well as chocolate. Caffeine constitutes 1-2% of roasted coffee beans, 3.5% of fresh tea leaves, and approximately 2% of mate leaves (Spiller, '84; Graham, '84a,b). Many over-the-counter medications, such as cold and allergy tablets, headache medicines, diuretics, and stimulants also contain caffeine, although they lead to relatively minimal intake (FDA, '86). In epidemiological studies, it is assumed that one cup of coffee contains < or =100 mg of caffeine, and soft drinks, such as colas, contain 10-50 mg of caffeine per 12-ounce serving. The per-capita consumption of caffeine from all sources is estimated to be about 3-7 mg/kg per day, or approximately 200 mg/day (Barone and Roberts, '96). Consumption of caffeinated beverages during pregnancy is quite common (Hill et al., '77) and is estimated to be approximately 144 mg/day, or 2.4 mg/kg for a 60-kg human (Morris and Weinstein, '81). However, pregnant women appear to consume slightly less than do other adults, approximately 1 mg/kg per day (Barone and Roberts, '96). This decrease may be interrelated with taste aversion (Hook, '76; Little, '82). The medical literature contains many varied references that appear to indicate that human adverse reproductive/developmental effects are produced by caffeine. If caffeine indeed causes such effects, the reproductive consequences could be very serious because caffeine-containing foods and beverages are consumed by most of the human populations of the world, and consumption in the United States is estimated to be 4.5-kg/person/year (Narod et al., '91). Therefore, the medical literature dealing with developmental and reproductive risks of caffeine was reviewed, and the biological plausibility of the epidemiological and animal findings, as well as the methods and conclusions of previous investigators, were evaluated. The epidemiological studies describe exposures of women to caffeine during pregnancy, as well as the occurrence of congenital malformations, fetal growth retardation, small-for-date babies, miscarriages (spontaneous abortions), behavioral effects, and maternal fertility problems that presumably resulted from the caffeine consumption. A few epidemiological studies were concerned with the genetic effects of preconception exposures to caffeine. Animal studies, conducted mostly in pregnant rats and mice, were designed to produce malformations. The objectives of the present review are to summarize the findings from the various clinical and animals studies, objectively discuss the merits and/or faults inherent in the studies and establish a global reproductive risk assessment for caffeine consumption in humans during pregnancy. It should be noted that evaluation of the developmental risks of caffeine based solely on epidemiological studies is difficult because the findings are inconsistent. Even more important, is the fact that caffeine users are subject to multiple confounding factors that make analyses difficult and prevent investigators from reaching definitive conclusions. For example, the caffeine content of foods and beverages can vary considerably, which can interfere with obtaining valid interpretations from many human studies. Isolated epidemiological studies dealing with the risk of abortion, without evaluating other developmental and reproductive effects, are the most difficult to interpret, because they present special problems that are sometimes ignored in epidemiological studies. The results of animal studies are probably most helpful in solving some of the dilemmas created by the epidemiological studies. An animal study reported in 1960 first focused our attention on the potential developmental effects of caffeine. However, the exposure reported by Nishimura and Nakai ('60) was an intraperitoneal dosage of 250 mg/kg in the mouse, an extremely high dosage that would result in a blood plasma level that could never be obtained from consuming caffeine containing products. More recent animal studies have demonstrated, that depending on the method of administration and species, the developmental NOEL in rodents is approximately 30 mg/kg per day, the teratogenic NOEL is 8,100 mg/kg per day, and the reproductive NOEL approximately 80-120 mg/kg per day. Lack of biological plausibility to support the concept that caffeine has been responsible for human malformations is another important part of this analysis. For example, no one has described the Caffeine "teratogenic syndrome," a cluster of malformations associated with caffeine ingestion. Proven human teratogens have an identifiable syndrome. The malformations described in the animal studies at very high doses fit the description of vascular disruptive types of malformations. (ABSTRACT TRUNCATED)
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Affiliation(s)
- M S Christian
- Argus International and Argus Research Laboratories, Horsham, Pennsylvania 19044, USA.
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Tickner JA, Schettler T, Guidotti T, McCally M, Rossi M. Health risks posed by use of Di-2-ethylhexyl phthalate (DEHP) in PVC medical devices: a critical review. Am J Ind Med 2001; 39:100-11. [PMID: 11148020 DOI: 10.1002/1097-0274(200101)39:1<100::aid-ajim10>3.0.co;2-q] [Citation(s) in RCA: 323] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND Polyvinyl chloride plastics (PVC), made flexible through the addition of di-2-ethylhexyl phthalate (DEHP), are used in the production of a wide array of medical devices. From the late 1960s, leaching of DEHP from PVC medical devices and ultimate tissue deposition have been documented. METHODS A critical review of DEHP exposure, metabolism, and toxicity data from human and animals studies was undertaken. A brief analysis of alternatives to DEHP-plasticized PVC for use in medical device manufacture was completed. RESULTS DEHP leaches in varying concentrations into solutions stored in PVC medical devices. Certain populations, including dialysis patients and hemophiliacs may have long-term exposures to clinically important doses of DEHP, while others, such as neonates and the developing fetus, may have exposures at critical points in development. In vivo and in vitro research links DEHP or its metabolites to a range of adverse effects in the liver, reproductive tract, kidneys, lungs, and heart. Developing animals are particularly susceptible to effects on the reproductive system. Some adverse effects in animal studies occur at levels of exposure experienced by patients in certain clinical settings. DEHP appears to pose a relatively low risk of hepatic cancer in humans. However, given lingering uncertainties about the relevance of the mechanism of action of carcinogenic effects in rodents for humans and interindividual variability, the possibility of DEHP-related carcinogenic responses in humans cannot be ruled out. CONCLUSIONS The observed toxicity of DEHP and availability of alternatives to many DEHP-containing PVC medical devices presents a compelling argument for moving assertively, but carefully, to the substitution of other materials for PVC in medical devices. The substitution of other materials for PVC would have an added worker and community health benefit of reducing population exposures to DEHP, reducing the creation of dioxin from PVC production and disposal, and reducing risks from vinyl chloride monomer exposure.
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Affiliation(s)
- J A Tickner
- Lowell Center for Sustainable Production, Department of Work Environment, University of Massachusetts, Lowell, MA 01854, USA.
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Abstract
BACKGROUND Cadmium is a well-known animal teratogen. Caffeine is an alkaloid widely consumed by humans. Interactions between teratogens and nonteratogenic doses of other agents are becoming widely studied, as they may shed light on understanding mechanisms of teratogenicity or possible prevention of teratogenic effects. METHODS C57BL/6JBK mice were injected intraperitoneally (ip) with cadmium sulfate (Cd) at 0, 1.00 (LDCd), 2.50 (MDCd), or 5.00 (HDCd) mg/kg, immediately followed by subcutaneous (sc) administration of 0 or 50 mg/kg caffeine (CAFF) on gestation day (GD) 9. Fetuses were examined on GD 18 for ectrodactyly and other gross morphological malformations. RESULTS Amelioration of cadmium-induced forelimb ectrodactyly by CAFF was seen in both the high-dose cadmium (HDCd = 65.4%, HDCd+CAFF = 39.2%) and medium-dose cadmium (MDCd = 46.2%, MDCd+ CAFF = 20.8%) treatment groups (P < 0.025). Bilateral expression of ectrodactyly was also decreased in the presence of caffeine. A statistically significant reduction in Cd-induced abnormalities, including: eye, abdominal, and other skeletal defects, was not seen with caffeine addition, although they did trend downward in the caffeine-supplemented groups. Litter size, fetal weight, fetal mortality, and dam weight also were not affected by co-treatment with caffeine. CONCLUSIONS This study provides evidence that a subteratogenic dose of caffeine can ameliorate cadmium-induced forelimb ectrodactyly in the Cd-sensitive C57BL/6J inbred mouse strain.
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Affiliation(s)
- J Lutz
- Department of Biological Sciences, DePaul University, Chicago, Illinois 60614, USA
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Pennanen SM, Heiskanen KM, Savolainen KM, Komulainen H. Effects of 2-ethylhexanoic acid on the production of reactive oxygen species in human polymorphonuclear leukocytes in vitro. Toxicol Lett 2000; 117:79-84. [PMID: 11033236 DOI: 10.1016/s0378-4274(00)00243-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
2-Ethylhexanoic acid (2-EHA), is an industrial chemical and a toxic biotransformation product of the plasticizer di(2-ethylhexyl)phthalate. Its immunological effects are unknown. 2-EHA resembles structurally C18 fatty acids, which are known activators of respiratory burst in human polymorphonuclear leukocytes (PMNL). Therefore, we exposed PMNL to 2-EHA in vitro and measured the production of reactive oxygen species (ROS) and explored the associated cellular mechanisms. 2-EHA (10-2000 microM) inhibited dose-dependently formyl-methionyl-leucyl-phenylalanine (FMLP)-induced respiratory burst in PMNL. Moreover, 2-EHA decreased oxidative burst evoked by the protein kinase C (PKC) activators, phorbol myristate acetate (PMA) and dioctanoyl-s,n-glycerol (DIC(8)). 2-EHA affected neither the levels of free intracellular calcium nor inhibited PKC. The results indicate that 2-EHA inhibits activation of PMNL to produce ROS, i.e. has an immunosuppressive effect in vitro. The site of action in the PKC is after activation of this enzyme.
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Affiliation(s)
- S M Pennanen
- Finnish Institute of Occupational Health, P.O. Box 93, FIN-70701, Kuopia, Finland.
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Aulmann W, Pittermann W, Bartnik F, Sterzel W, Kästner W, Potokar M. Developmental toxicity of 2-ethylhexyl stearate. Food Chem Toxicol 2000; 38:57-63. [PMID: 10685014 DOI: 10.1016/s0278-6915(99)00124-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
2-Ethylhexyl stearate was investigated in an embryo-/foetotoxicity and teratogenicity study on rats according to OECD guidelines for the testing of chemicals (No. 414). Dose levels of 0 (arachidis oil), 100, 300 and 1000mg/kg body weight/day were administered by gavage. Dams tolerated the applied dose levels without any toxic effects. Pre- and post-implantation loss and mean numbers of resorptions were unaffected by treatment. All parameters were comparable with the animals of the control group. Skeletal and visceral investigations revealed no treatment-related malformations. For embryo-/foetotoxicity, teratogenicity and maternal toxicity a NOAEL of 1000mg/kg was deduced.
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Affiliation(s)
- W Aulmann
- Henkel KGaA, D-40191, Düsseldorf, Germany.
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Waterman SJ, Ambroso JL, Keller LH, Trimmer GW, Nikiforov AI, Harris SB. Developmental toxicity of di-isodecyl and di-isononyl phthalates in rats. Reprod Toxicol 1999; 13:131-6. [PMID: 10213520 DOI: 10.1016/s0890-6238(99)00002-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The developmental toxicity of di-isodecyl phthalate (DIDP; CAS RN 68515-49-1) and di-isononyl phthalate (DINP; CAS RN 68515-48-0) were investigated in Sprague-Dawley rats. DIDP and DINP were administered by gavage to mated rats at doses of 0, 100, 500, and 1000 mg/kg/d on Gestation Days (GD) 6 through 15. Cesarean sections were performed on GD 21 and the fetuses removed for evaluation. Maternal weight gain and food consumption were significantly reduced at 1000 mg/kg/d during the exposure period. No treatment-related effects were noted at cesarean section, nor were there any fetal morphologic observations except for an increased frequency of seventh cervical and rudimentary lumbar ribs at the maternally toxic exposure level of 1000 mg/kg/d. Under these study conditions, mild maternal and developmental effects were observed at 1000 mg/kg/d. Both maternal and developmental NOAELs were therefore established at 500 mg/kg/d. The results indicate that neither DIDP nor DINP is teratogenic or a selective developmental toxicant.
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Affiliation(s)
- S J Waterman
- Exxon Biomedical Sciences, Toxicology Division, East Millstone, NJ 08875, USA.
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Bui LM, Taubeneck MW, Commisso JF, Uriu-Hare JY, Faber WD, Keen CL. Altered zinc metabolism contributes to the developmental toxicity of 2-ethylhexanoic acid, 2-ethylhexanol and valproic acid. Toxicology 1998; 126:9-21. [PMID: 9585088 DOI: 10.1016/s0300-483x(97)00171-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
It has been hypothesized that the developmental toxicity of certain compounds is, in part, due to maternal toxicity resulting in alterations in zinc (Zn) metabolism that affects the developing conceptus. In the present work the effects of developmentally toxic doses of 2-ethylhexanoic acid (EHXA), 2-ethylhexanol (EHXO), and valproic acid (VPA) on Zn metabolism were investigated in the pregnant rat. In experiment 1, dams were intubated with EHXA (3.13, 6.25, 9.38 or 12.5 mmol/kg), EHXO (6.25, 9.38 or 12.5 mmol/kg), VPA (1.56, 3.13, 6.25 or 9.38 mmol/kg), or corn oil (control; 1.0 ml/kg) at 14:00 h on gestation day (GD) 11.5, intubated with 32 microCi 65Zn at 22:00 h, and then killed at 08:00 h on GD 12.5. At the higher dose levels of EHXA and EHXO, and at all dosages of VPA, the percentage of 65Zn retained in maternal liver was higher, while that in the embryos was lower, than in controls. Chemical-associated changes in 65Zn distribution were associated with increased maternal liver metallothionein (MT) concentrations. In experiment 2, dams were fed diets containing 1, 25 or 97 microg Zn/g from GD 0-16 and intubated with 3.5 mmol EHXA or 1.0 ml corn oil/kg/d from GD 8-15. Dams were killed on GD 16 or 19. High incidences of encephalocele and tail defects were noted in the GD 16 fetuses of EHXA-treated dams fed either the low or adequate Zn diet, the highest incidences being in the low Zn group. On GD 19 the incidence of tail defects tended to be higher in the EHXA groups than in oil-treated controls, the highest incidence occurring in the low Zn EHXA group. Encephalocele was only observed in the low Zn EHXA-treated group. Fetal weight and crown-rump lengths were decreased by EHXA treatment and low dietary Zn. The incidence of rib anomalies was higher in the EHXA-exposed groups than in their respective oil controls. In experiment 3, GD 10.5 embryos collected from control dams were cultured for 48 h in serum from control or EHXA-treated male rats fed 4.5 or 25.0 microg Zn/g diets. Embryos cultured in either EHXA or low Zn sera exhibited delayed development; the addition of Zn to these sera eliminated their developmental toxicity. These results support the hypothesis that certain chemicals which induce maternal toxicity act, in part, to influence embryonic Zn metabolism and trigger abnormal development. Importantly, the teratogenic effects of these chemicals can be modulated by dietary Zn intake.
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Affiliation(s)
- L M Bui
- Department of Nutrition, University of California, Davis 95616-8669, USA
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39
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Hellwig J, Jäckh R. Differential prenatal toxicity of one straight-chain and five branched-chain primary alcohols in rats. Food Chem Toxicol 1997; 35:489-500. [PMID: 9216748 DOI: 10.1016/s0278-6915(97)00007-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
One straight-chain alcohol (n-octanol) and five branched-chain alcohols [2-ethylhexanol (2-EH), isodecanol, two types of isononanol and a C7-9-11 alcohol] were investigated for developmental effects in Wistar rats at equimolar dose levels (0, 1, 5 and 10 mmol/kg by gavage from gestation day 6 to 15; 10 animals per group). n-Octanol and both isononanols were also investigated in a supplementary experiment at 7.5 mmol/kg/day. Pronounced maternal but no developmental toxicity was achieved with n-octanol. C7-9-11 alcohol, which is a mixture of isomers mostly of a low degree of branching (alpha-methyl), showed no adverse effects at any dose levels. The two types of isononanols (typical mixtures of two different sets of isomers originating from two different production routes) exhibited a marked degree of maternal and foetal toxicity at 7.5 and 10 mmol/kg and slight foetal effects at 5 mmol/kg. Because of maternal toxicity in the top dose, a statistically significant increase in malformations was obtained only in the dose window of 7.5 mmol/kg in the supplementary experiment. Isodecanol (a mixture of different isomers) elicited maternal toxicity at 10 mmol/kg and caused a low incidence of retardations and rare malformations at that dose level. Some maternal signs but no foetal effects were observed at 5 mmol/kg. 2-EH showed strong maternal and also foetal toxicity at 10 mmol/kg and slight maternal and foetal toxicity at 5 mmol/kg. The differential responses to the test materials indicate that, at present, within this chemical class of alcohols, the potential for developmental toxicity has to be investigated case by case for each individual structure.
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Affiliation(s)
- J Hellwig
- Department of Toxicology, BASF Aktiengesellschaft, Ludwigshafen, Germany
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40
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Hellwig J, Freudenberger H, Jäckh R. Differential prenatal toxicity of branched phthalate esters in rats. Food Chem Toxicol 1997; 35:501-12. [PMID: 9216749 DOI: 10.1016/s0278-6915(97)00008-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Several phthalate esters with alcohol moieties ranging from C5-C10 chains were investigated for prenatal toxicity in 10 rats per group after gavage administration of 0, 40, 200 and 1000 mg/kg/day from gestation day 6 to 15. At 1000 mg/kg di(2-ethylhexyl) phthalate showed clear foetotoxicity, embryolethality and teratogenicity. No significant effects were recorded at 40 and 200 mg/kg. Di-711-phthalate, a phthalic ester with linear components and a predominantly alpha-methyl branching type, and di-isopentylphthalate showed a very similar spectrum of effects. Interestingly, the alcohol moiety of di-711-phthalate, 711-alcohol was developmentally inactive in a previous experiment. Di-iso-decylphthalate and three types of di-iso-nonylphthalate showed foetal effects of borderline significance at 1000 mg/kg/day.
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Affiliation(s)
- J Hellwig
- Department of Toxicology, BASF Aktiengesellschaft, Ludwigshafen, Germany
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Haghdoost NR, Newman LM, Johnson EM. Multiple chemical exposures: synergism vs. individual exposure levels. Reprod Toxicol 1997; 11:9-27. [PMID: 9138638 DOI: 10.1016/s0890-6238(96)00156-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Exposure to single chemicals is known to produce congenital malformations in both pregnant animals and humans exposed at sufficiently high intensity. However, real life involves multiple, simultaneous exposures. Using as a database the 43 multiple chemical exposure studies located by Nelson (Teratology 49:33-71; 1994) where synergism was reported, we explored the degree to which such concerns may be realistic from the viewpoint of the current standard developmental toxicity safety evaluation process. Focusing on the assessment of the lowest tested dose of a given agent participating in synergistic activity as compared to its threshold level for eliciting toxicity when administered alone, we found that while the availability of adequate data was limited, all cases, with the possible exception of one, demonstrated synergistic toxic expression only when at least one, and usually both, compounds were used at or above their individual threshold for toxicity. These findings suggest that in animals such phenomena of synergistic chemical interactions are likely to occur only when at least one and more likely both agents are administered at or above their individual threshold for toxicity. To the extent animal studies are predictive of human developmental hazards due to single chemical exposures, available data do not establish multiple chemical exposures as a major human developmental concern.
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Affiliation(s)
- N R Haghdoost
- Daniel Baugh Institute, Jefferson Medical College, Philadelphia, Pennsylvania 19107, USA
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42
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Ema M, Harazono A, Miyawaki E, Ogawa Y. Characterization of developmental toxicity of mono-n-benzyl phthalate in rats. Reprod Toxicol 1996; 10:365-72. [PMID: 8888408 DOI: 10.1016/0890-6238(96)00082-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The objective of this study was to characterize the developmental toxicity of mono-n-benzyl phthalate (MBeP), which is one of the major metabolites of n-butyl benzyl phthalate. Pregnant rats were given MBeP by gastric intubation at 250, 375, 500, or 625 mg/kg on days 7 to 9, 10 to 12, or 13 to 15 of pregnancy. A significantly increased incidence of postimplantation loss was found at 500 mg/kg and above regardless of the days of administration. While administration of MBeP on days 7 to 9 or 13 to 15 at 375 mg/kg and above was significantly teratogenic, no evidence of teratogenicity was detected when MBeP was given on days 10 to 12. Deformity of the vertebral column and ribs and dilation of the renal pelvis were frequently observed after administration on days 7 to 9. Cleft palate and fused sternebrae were exclusively found after administration on days 13 to 15. These findings indicate that the susceptibility and spectrum of the developmental toxicity of MBeP vary with the developmental stages at the time of administration.
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Affiliation(s)
- M Ema
- National Institute of Health Sciences, Osaka Branch, Japan
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43
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Pennanen S, Kojo A, Pasanen M, Liesivuori J, Juvonen RO, Komulainen H. CYP enzymes catalyze the formation of a terminal olefin from 2-ethylhexanoic acid in rat and human liver. Hum Exp Toxicol 1996; 15:435-42. [PMID: 8735469 DOI: 10.1177/096032719601500512] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
1. The metabolism of 2-ethylhexanoic acid (2-EHA) was studied in rat, mouse and human liver microsomes in vitro. The metabolites of 2-EHA were identified as methylated derivatives by gas chromatography-mass spectrometry. 2. 2-Ethyl-1,6-hexanedioic acid was the main metabolite produced in rat, mouse and human liver microsomes. Unsaturated 2-ethyl-5-hexenoic acid, a terminal olefin, was produced only in human liver microsomes and phenobarbital-induced rat liver microsomes. The cytochrome P450 (CYP) inhibitors metyrapone, SKF 525A, triacetyloleandomycin (TAO), quinidine and the cytochrome P450 reductase antibody abolished its formation both in rat and human microsomes. 3. The metabolites were analyzed also in vivo in urine of 2-EHA-exposed rats and in urine of sawmill workers exposed occupationally to 2-EHA. Both rat and human urine contained 2-ethyl-1,6-hexanedioic acid as the main metabolite and also 2-ethyl-5-hexenoic acid. Metyrapone, SKF 525A and TAO all decreased drastically the formation of 2-ethyl-5-hexenoic acid in the rat. 4. The data indicate that (1) several CYP families (CYP2A, CYP2B, CYP2D and CYP3A) could be responsible for the hepatic metabolism of 2-EHA, (2) the same metabolites were formed in rats and man and (3) an unsaturated terminal olefin, 2-ethyl-5-hexenoic acid is formed in the liver.
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Affiliation(s)
- S Pennanen
- National Public Health Institute, Division of Environmental Health, Kuopio, Finland
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Ema M, Kurosaka R, Amano H, Ogawa Y. Comparative developmental toxicity of butyltin trichloride, dibutyltin dichloride and tributyltin chloride in rats. J Appl Toxicol 1995; 15:297-302. [PMID: 7594199 DOI: 10.1002/jat.2550150411] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Butyltin trichloride (BT), dibutyltin dichloride (DBT) and tributyltin chloride (TBT) were compared for their developmental toxicity including teratogenic potential following administration during the susceptible period for the teratogenesis of DBT. Pregnant rats were given either BT at a dose of 1000, 1500 or 2000 mg kg-1, DBT at a dose of 10 or 15 mg kg-1 or TBT at a dose of 40 or 80 mg kg-1 by gastric intubation on days 7 and 8 of pregnancy. Although maternal toxicity occurred, as evidenced by a significantly increased maternal lethality at 1500 and 2000 mg kg-1 and decreased maternal weight gain at 1000 and 1500 mg kg-1, no significant increase in the incidences of postimplantation loss and malformed fetuses were observed after treatment with BT. Treatment with DBT resulted in a significantly lower maternal weight gain, lower fetal weight and higher postimplantation embryolethality. A significantly and markedly increased incidence of fetuses with malformations, such as exencephaly, cleft jaw, cleft lip, ankyloglossia, club foot, deformity of the vertebral column in the cervical and thoracic regions and of the ribs and ano- or microphthalmia, was observed in both groups treated with DBT. While treatment with TBT at 40 and 80 mg kg-1 caused a significantly decreased maternal weight gain and increased postimplantation embryolethality, no significantly increased incidence of malformed fetuses occurred. It could be concluded that BT, DBT and TBT are different in the susceptibility and spectrum of developmental toxicity.
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Affiliation(s)
- M Ema
- National Institute of Health Sciences, Osaka Branch, Japan
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45
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Narotsky MG, Kavlock RJ. A multidisciplinary approach to toxicological screening: II. Developmental toxicity. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1995; 45:145-71. [PMID: 7783251 DOI: 10.1080/15287399509531987] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
As part of the validation of an integrated bioassay for systemic toxicity, neurotoxicity, and developmental toxicity, we evaluated the effects of four pesticides, four chlorinated solvents, and two other industrial chemicals in Fischer 344 rats. The pesticides included carbaryl, triadimefon, chlordane, and heptachlor; the solvents included dichloromethane (DCM), carbon tetrachloride, trichloroethylene (TCE), and tetrachloroethylene (perchloroethylene, PER); and the industrial chemicals were di(2-ethylhexyl)phthalate (DEHP) and phenol. In the developmental toxicity studies, timed-pregnant rats were treated by gavage with vehicle or 1 of 2 dose levels of each compound on gestation d 6-19. The dams were allowed to deliver and their litters were examined on postnatal d 1, 3, and 6. Litter weights were determined on postnatal d 1 and 6. Implants were also counted to determine prenatal loss. Maternal toxicity was evidenced by dose-related alterations in weight gain for all 10 compounds. Clinical signs of maternal toxicity were present for all chemicals except chlordane and heptachlor. DEHP exposure resulted in the most pronounced developmental toxicity (high levels of pre- and postnatal mortality), whereas chlordane induced extensive postnatal loss. Of the solvents, only DCM did not cause a high incidence of full-litter resorption. Phenol, heptachlor, triadimefon, and carbaryl showed only slight potential for developmental toxicity. Malformations suggestive of teratogenicity included kinked tail (phenol), microphthalmia (TCE, PER, DEHP), and cleft palate with renal agenesis (DEHP). Although several findings (eye defects caused by TCE and PER, full-litter resorption and delayed parturition caused by PER, and delayed parturition/dystocia associated with triadimefon) have not been previously reported, the results are generally consistent with previous reports and highlight the importance and relative ease of incorporation of developmental evaluations into a multidisciplinary screening battery.
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Affiliation(s)
- M G Narotsky
- ManTech Environmental Technology, Inc., Research Triangle Park, North Carolina, USA
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Ema M, Kurosaka R, Amano H, Ogawa Y. Further evaluation of the developmental toxicity of tributyltin chloride in rats. Toxicology 1995; 96:195-201. [PMID: 7900160 DOI: 10.1016/0300-483x(94)02920-p] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The objective of this study was to further evaluate the developmental toxicity of tributyltin chloride (TBTCl) in rats. Pregnant rats were given TBTCl by gastric intubation at a dose of 25, 50 or 100 mg/kg on days 7-9, days 10-12 or days 13-15 of pregnancy. A significant increase in the incidence of post-implantation loss was found in the groups treated with TBTCl on days 7-9 at 25 and 50 mg/kg and on days 10-12 at 100 mg/kg, but not in the groups treated with TBTCl on days 13-15. No significant increase in the incidence of malformed fetuses was observed after treatment with TBTCl on days 7-9. A significant increase incidence of malformed fetuses was detected when TBTCl was given on days 10-12 at 100 mg/kg and on days 13-15 at 25, 50 and 100 mg/kg. The most predominant malformation was cleft palate. It could be concluded that the manifestation of deviant development induced by TBTCl varies with the developmental stage at the time of administration and TBTCl possesses teratogenic potential with developmental phase specificity.
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Affiliation(s)
- M Ema
- National Institute of Health Sciences, Osaka Branch, Japan
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47
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Hansen DK, Grafton TF. Evaluation of di(2-ethylhexyl)phthalate-induced embryotoxicity in rodent whole-embryo culture. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1994; 43:361-7. [PMID: 7966444 DOI: 10.1080/15287399409531927] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Di(2-ethylhexyl)phthalate (DEHP) is a commonly used plasticizer. Human exposure has been documented, and therefore it is important to investigate the toxic potential of this compound. When DEHP was administered in vivo, it was found to be a developmental toxicant in rodents. The purpose of this investigation was to determine if DEHP was directly embryotoxic to rat embryos. Embryos were cultured for 44 h beginning on gestational d 10. Embryos were cultured in rat serum to which DEHP was added to attain final concentrations within the 0.01-2.0% range. DEHP decreased growth and development at all tested concentrations higher than 0.5%. These results suggest that the parent compound itself is able to alter normal embryonic growth and development; however the high embryotoxic concentrations are unlikely to be attained in vivo.
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Affiliation(s)
- D K Hansen
- Department of Health and Human Services, National Center for Toxicological Research, Food and Drug Administration, Jefferson, Arkansas 72079-9502
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48
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Nelson BK. Interactions in developmental toxicology: a literature review and terminology proposal. TERATOLOGY 1994; 49:33-71. [PMID: 8171395 DOI: 10.1002/tera.1420490107] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Developmental toxicologists have investigated the interactive effects from concurrent exposures to a variety of chemical and physical agents, including therapeutic drugs, industrial agents, and some biological organisms or their toxins. Of approximately 160 reports of concurrent exposures reviewed in this paper, about one third report no interactive effects (including additive effects--usually referring to response--as opposed to dose-additivity); another one third report antagonistic effects, and the final third report potentiative or synergistic effects. The quality of the studies is highly variable. Frequently, only small numbers of animals were included, and very few dose levels were evaluated. Maternal toxicity was rarely discussed. Time-effect relationships were examined infrequently. In addition, these studies are also inconsistent in the use of terms to describe interactive effects, and more than 90% of the terms were not in harmony with currently accepted definitions in toxicology. Because interaction studies will continue to be important in the future, this paper proposes uniform usage of terms for additivity and interactions in developmental toxicology: additivity (the combined effect of two or more developmental toxicants approximates the sum of the effects of the agents administered separately); antagonism (the combined effect of two or more agents, one or more of which are present at doses that would be developmentally toxic if given individually, is significantly less than the sum of the effects of the agents administered separately); potentiation (the increased effect of a developmental toxicant by concurrent action of another agent at a dose that is not developmentally toxic); synergism (the combined effect of two or more developmental toxicants is significantly greater than the sum of the effects of each agent administered alone); and, interaction if more precise terminology does not apply.
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Affiliation(s)
- B K Nelson
- Centers of Disease Control, NIOSH, Cincinnati, Ohio 45226
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49
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Sundberg C, Wachtmeister CA, Lundgren B, DePierre JW. Comparison of the potencies of (+)- and (-)-2-ethylhexanoic acid in causing peroxisome proliferation and related biological effects in mouse liver. Chirality 1994; 6:17-24. [PMID: 8018466 DOI: 10.1002/chir.530060106] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Male C57BL/6 mice were exposed to 1% (w/w) (+)- or (-)-2-ethylhexanoic acid or an equimolar mixture of these enantiomers in their diet for 4 or 10 days. A significant increase in liver weight and a 2- to 3-fold increase in the protein content of the mitochondrial fraction were seen in all cases. Peroxisomal palmitoyl-CoA oxidation was increased 2- to 3.5-fold after 4 days of treatment and 4- to 5-fold after 10 days, while the corresponding increases in peroxisomal lauroyl-CoA oxidase activity were 2- to 3-fold and 9- to 12-fold, respectively. Peroxisomal catalase activity was unchanged, whereas the microsomal and cytosolic activities were increased 2- to 3-fold and 6- to 16-fold, respectively. These treatments also induced microsomal omega-hydroxylation of lauric acid 7-fold and soluble epoxide hydrolase activity in the mitochondrial and cytosolic fractions, as well as microsomal epoxide hydrolase activity about 50-100%. The only significant differences observed between the effects of (+)-2-ethylhexanoic acid and its (-)-enantiomer were on peroxisomal palmitoyl-CoA oxidation and lauroyl-CoA oxidase activity after 4 days of treatment. In both these cases the (+)-enantiomer resulted in increases which were 50-75% greater than those seen with the (-)-form.
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Affiliation(s)
- C Sundberg
- Department of Biochemistry, Wallenberg Laboratory, Stockholm University, Sweden
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Field EA, Price CJ, Sleet RB, George JD, Marr MC, Myers CB, Schwetz BA, Morrissey RE. Developmental toxicity evaluation of diethyl and dimethyl phthalate in rats. TERATOLOGY 1993; 48:33-44. [PMID: 8351646 DOI: 10.1002/tera.1420480107] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Diethyl phthalate (DEP) and dimethyl phthalate (DMP), phthalic acid ester (PAE) plasticizers, were evaluated for developmental toxicity because of reports in the literature that some PAE were embryotoxic and teratogenic. A previous study (Singh et al., '72) suggested that an increased incidence of skeletal defects in rats might result from gestational exposure to DEP (0.6-1.9 g/kg) or DMP (0.4-1.3 g/kg), ip, on gestational days (gd) 5, 10, and 15. In the current study DEP (0, 0.25, 2.5, and 5%) or DMP (0, 0.25, 1, and 5%) in feed (approximately 0.2-4.0 g/kg/day) were supplied to timed-mated rats from gd 6 to 15. Treatment with 5% DMP resulted in increased relative maternal liver weight. Also, animals exhibited reduced body weight gain during treatment (5% DEP or DMP) and during gestation (5% DEP). Weight gain corrected for gravid uterine weight was also reduced in animals fed 5% DEP. However, high-dose treatment with either DEP or DMP resulted in changes in food and water consumption paralleling the body weight reductions, suggesting that apparent toxic effects on maternal body weight may reflect PAE/feed unpalatability. Treatment with 2.5% DEP resulted in only transient changes in body weight during early treatment. The only maternal effects at 0.25 or 1% DMP were minor changes in food and/or water consumption, and there were no effects at 0.25% DEP. Thus, the NOAELs for maternal toxicity were 1% DMP and 0.25% DEP. In contrast to the observed maternal toxicity, there was no effect of DEP or DMP treatment on any parameter of embryo/fetal development, except an increased incidence of supernumerary ribs (a variation) in the 5% DEP group. These results do not support the conclusion of other investigators that DEP and DMP are potent developmental toxicants. Rather, they suggest that the short-chain PAE are less developmentally toxic than PAE with more complex substitution groups, e.g., di(2-ethylhexyl) phthalate, mono(2-ethylhexyl) phthalate, and butyl benzyl phthalate.
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Affiliation(s)
- E A Field
- Research Triangle Institute, Research Triangle Park, North Carolina 27709-2194
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