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Borgatta M, Wild P, Hopf NB. Blood absorption toxicokinetics of glycol ethers after inhalation: A human controlled study. Sci Total Environ 2022; 816:151637. [PMID: 34774961 DOI: 10.1016/j.scitotenv.2021.151637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 10/26/2021] [Accepted: 11/08/2021] [Indexed: 06/13/2023]
Abstract
Glycol ethers are organic solvents present in countless products for professional and domestic use. The main toxicological concerns are hematotoxicity, respiratory and reproductive toxicity. The general population can be exposed when using products containing one or several glycol ethers that evaporate or if sprayed, generate aerosols that can be inhaled. The rate at which glycol ethers enters blood following inhalation exposure are unknown in humans, and chemical risk assessors only rely on animal and in vitro toxicity studies. Propylene glycol monomethyl ether (PGME) and propylene glycol monobutyl ether (PGBE) are two examples of glycol ethers used worldwide. Our study aimed to provide human toxicokinetic data after inhalation exposure of low PGME and PGBE concentrations tested alone or in mixture. Healthy participants (n = 28) were exposed to 35 ppm (131 mg/m3) of PGME and 15 ppm (i.e., 83 mg/m3) of PGBE for 2 or 6 h. Blood was regularly collected during the exposure sessions. PGME and PGBE were immediately bioavailable in blood during exposure, and the mean absorption rates were up to 13 μg/L/min and 2.45 μg/L/min, respectively. Maximum mean blood concentration (Cmax) was 2.91 mg/L and 0.41 mg/L for PGME and PGBE. The cumulative internal doses over time (area under the curve, AUC) were 11 mg∗h/L and 1.81 mg∗h/L for PGME and PGBE. PGME and PGBE total blood uptake could possibly be higher in physically active individuals, such as workers. We recommend that glycol ethers present on the market undergo toxicological testing with the internal doses we found in our toxicokinetic study.
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Affiliation(s)
- Myriam Borgatta
- Center for Primary Care and Public Health (Unisanté), Department of Occupational and Environmental Health, University of Lausanne, 1011 Lausanne, Switzerland.
| | - Pascal Wild
- Center for Primary Care and Public Health (Unisanté), Department of Occupational and Environmental Health, University of Lausanne, 1011 Lausanne, Switzerland; Institute for Research and Safety (INRS), Vandoeuvre les Nancy, France.
| | - Nancy B Hopf
- Center for Primary Care and Public Health (Unisanté), Department of Occupational and Environmental Health, University of Lausanne, 1011 Lausanne, Switzerland.
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2
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Murray JS, Finch SC, Puddick J, Rhodes LL, Harwood DT, van Ginkel R, Prinsep MR. Acute Toxicity of Gambierone and Quantitative Analysis of Gambierones Produced by Cohabitating Benthic Dinoflagellates. Toxins (Basel) 2021; 13:toxins13050333. [PMID: 34063025 PMCID: PMC8147941 DOI: 10.3390/toxins13050333] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 04/29/2021] [Accepted: 05/03/2021] [Indexed: 01/05/2023] Open
Abstract
Understanding the toxicity and production rates of the various secondary metabolites produced by Gambierdiscus and cohabitating benthic dinoflagellates is essential to unravelling the complexities associated with ciguatera poisoning. In the present study, a sulphated cyclic polyether, gambierone, was purified from Gambierdiscus cheloniae CAWD232 and its acute toxicity was determined using intraperitoneal injection into mice. It was shown to be of low toxicity with an LD50 of 2.4 mg/kg, 9600 times less toxic than the commonly implicated Pacific ciguatoxin-1B, indicating it is unlikely to play a role in ciguatera poisoning. In addition, the production of gambierone and 44-methylgambierone was assessed from 20 isolates of ten Gambierdiscus, two Coolia and two Fukuyoa species using quantitative liquid chromatography–tandem mass spectrometry. Gambierone was produced by seven Gambierdiscus species, ranging from 1 to 87 pg/cell, and one species from each of the genera Coolia and Fukuyoa, ranging from 2 to 17 pg/cell. The production of 44-methylgambierone ranged from 5 to 270 pg/cell and was ubiquitous to all Gambierdiscus species tested, as well as both species of Coolia and Fukuyoa. The relative production ratio of these two secondary metabolites revealed that only two species produced more gambierone, G. carpenteri CAWD237 and G. cheloniae CAWD232. This represents the first report of gambierone acute toxicity and production by these cohabitating benthic dinoflagellate species. While these results demonstrate that gambierones are unlikely to pose a risk to human health, further research is required to understand if they bioaccumulate in the marine food web.
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Affiliation(s)
- J. Sam Murray
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (J.P.); (L.L.R.); (D.T.H.); (R.v.G.)
- New Zealand Food Safety Science and Research Centre, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand
- School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand;
- Correspondence:
| | - Sarah C. Finch
- AgResearch, Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand;
| | - Jonathan Puddick
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (J.P.); (L.L.R.); (D.T.H.); (R.v.G.)
| | - Lesley L. Rhodes
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (J.P.); (L.L.R.); (D.T.H.); (R.v.G.)
| | - D. Tim Harwood
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (J.P.); (L.L.R.); (D.T.H.); (R.v.G.)
- New Zealand Food Safety Science and Research Centre, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand
| | - Roel van Ginkel
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (J.P.); (L.L.R.); (D.T.H.); (R.v.G.)
| | - Michèle R. Prinsep
- School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand;
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Tillmann U, Krock B, Wietkamp S, Beran A. A Mediterranean Alexandrium taylorii (Dinophyceae) Strain Produces Goniodomin A and Lytic Compounds but Not Paralytic Shellfish Toxins. Toxins (Basel) 2020; 12:E564. [PMID: 32883001 PMCID: PMC7551950 DOI: 10.3390/toxins12090564] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/24/2020] [Accepted: 08/27/2020] [Indexed: 01/26/2023] Open
Abstract
Species of the dinophyte genus Alexandrium are widely distributed and are notorious bloom formers and producers of various potent phycotoxins. The species Alexandrium taylorii is known to form recurrent and dense blooms in the Mediterranean, but its toxin production potential is poorly studied. Here we investigated toxin production potential of a Mediterranean A. taylorii clonal strain by combining state-of-the-art screening for various toxins known to be produced within Alexandrium with a sound morphological and molecular designation of the studied strain. As shown by a detailed thecal plate analysis, morphology of the A. taylorii strain AY7T from the Adriatic Sea conformed with the original species description. Moreover, newly obtained Large Subunit (LSU) and Internal Transcribed Spacers (ITS) rDNA sequences perfectly matched with the majority of other Mediterranean A. taylorii strains from the databases. Based on both ion pair chromatography coupled to post-column derivatization and fluorescence detection (LC-FLD) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis it is shown that A. taylorii AY7T does not produce paralytic shellfish toxins (PST) above a detection limit of ca. 1 fg cell-1, and also lacks any traces of spirolides and gymnodimines. The strain caused cell lysis of protistan species due to poorly characterized lytic compounds, with a density of 185 cells mL-1 causing 50% cell lysis of cryptophyte bioassay target cells (EC50). As shown here for the first time A. taylorii AY7T produced goniodomin A (GDA) at a cellular level of 11.7 pg cell-1. This first report of goniodomin (GD) production of A. taylorii supports the close evolutionary relationship of A. taylorii to other identified GD-producing Alexandrium species. As GD have been causatively linked to fish kills, future studies of Mediterranean A. taylorii blooms should include analysis of GD and should draw attention to potential links to fish kills or other environmental damage.
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Affiliation(s)
- Urban Tillmann
- Alfred Wegener Institute-Helmholtz Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, D-27570 Bremerhaven, Germany; (B.K.); (S.W.)
| | - Bernd Krock
- Alfred Wegener Institute-Helmholtz Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, D-27570 Bremerhaven, Germany; (B.K.); (S.W.)
| | - Stephan Wietkamp
- Alfred Wegener Institute-Helmholtz Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, D-27570 Bremerhaven, Germany; (B.K.); (S.W.)
| | - Alfred Beran
- National Institute of Oceanography and Applied Geophysics—OGS, via Piccard 54, I-34151 Trieste, Italy;
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Mariani L, Grenni P, Barra Caracciolo A, Donati E, Rauseo J, Rolando L, Patrolecco L. Toxic response of the bacterium Vibrio fischeri to sodium lauryl ether sulphate residues in excavated soils. Ecotoxicology 2020; 29:815-824. [PMID: 32291616 DOI: 10.1007/s10646-020-02202-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/21/2020] [Indexed: 06/11/2023]
Abstract
Sodium lauryl ether sulphate (SLES) is the main chemical component in several lubricant products used for soil conditioning in the mechanized excavation industry using Earth Pressure Balance-Tunnel Boring Machines. During the tunnelling process, huge amounts of excavated soil are produced and the SLES presence can affect the subsequent re-use of this material as a by-product. Currently, there is still no regulatory indication of reliable and sensitive bioassays for monitoring soil quality during the excavation process. The main objective of this work was to verify if the Vibrio fischeri screening test was suitable as a consistent and precautionary tool for this specific purpose. Firstly, the ecotoxicity (EC20 and EC50) of the SLES standard solution and three commercial products (SLES content from 10 to 50%) were evaluated to select the most environmental friendly product. Subsequently, soil samples from about 2 years of tunnelling in a real construction site, conditioned with the selected product, were evaluated for their environmental compatibility with the prescriptions of an Italian site-specific protocol. The latter established 2 mg/L as a threshold value for SLES concentration in soil water extracts and a no toxic response (≤20%) for the Vibrio fischeri test. The comparison of the bacterium bioluminescence inhibition values (%) with analytical determinations showed an ecotoxicity when SLES was >2 mg/L. The toxicity was directly related to SLES concentration, indicating that the V. fischeri test and the SLES analyses are suitable tools for assessing excavated soil as a by-product, ensuring its safe reuse in accordance with a green production process (circular economy).
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Affiliation(s)
- L Mariani
- Water Research Institute, National Research Council (IRSA-CNR), Rome, Italy
| | - P Grenni
- Water Research Institute, National Research Council (IRSA-CNR), Rome, Italy
| | | | - E Donati
- Institute for Biological Systems, National Research Council (ISB-CNR), Rome, Italy
| | - J Rauseo
- Institute of Polar Science, National Research Council (ISP-CNR), Rome, Italy
| | - L Rolando
- Water Research Institute, National Research Council (IRSA-CNR), Rome, Italy
- Department of Ecological and Biological Science, Tuscia University, Rome, Italy
| | - L Patrolecco
- Institute of Polar Science, National Research Council (ISP-CNR), Rome, Italy
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Nesterkina M, Bilokon S, Alieksieieva T, Chebotar S, Kravchenko I. Toxic effect and genotoxicity of carvacrol ethers in Drosophila melanogaster. Mutat Res 2020; 821:111713. [PMID: 32593030 DOI: 10.1016/j.mrfmmm.2020.111713] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/26/2020] [Accepted: 06/16/2020] [Indexed: 06/11/2023]
Abstract
The present study investigated the effect of four carvacrol ethers (propyl-, butyl, octyl- and benzyl) on the viability, level of dominant lethal mutations of Drosophila melanogaster and their influence on the multiplication of the nuclear genome in salivary gland cells. The fertility and viability of fruit flies were assessed after oral administration (0.05 % to culture medium) and inhalation exposure (5 mg per 1 cm2 of polyvinyl alcohol film) of compounds 1‒4 and initial carvacrol. The influence of terpenoid and its ethers on the degree of chromosomes polyteny in salivary gland cells of D. melanogaster larvae has been revealed. Among all tested compounds, carvacrol exhibited the most significant impact on frequency of dominant lethal mutations, fecundity and insect survival when inhaled or adding to the culture medium. Oral administration of ethers 1‒4 was found to decrease the average level of chromosome polyteny degree (366 C-500 C) while pure carvacrol adding to culture medium had the opposite effect (763 C) compared to control (695 C). The possible mechanism of action for carvacrol and its ethers is discussed.
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Affiliation(s)
- Mariia Nesterkina
- Department of Organic and Pharmaceutical Technologies, Odessa National Polytechnic University, Odessa, 65044, Ukraine.
| | - Svitlana Bilokon
- Department of Genetics and Molecular Biology, Odessa I.I. Mechnikov National University, Odessa, 65082, Ukraine
| | - Tetiana Alieksieieva
- Department of Genetics and Molecular Biology, Odessa I.I. Mechnikov National University, Odessa, 65082, Ukraine
| | - Sabina Chebotar
- Department of Genetics and Molecular Biology, Odessa I.I. Mechnikov National University, Odessa, 65082, Ukraine
| | - Iryna Kravchenko
- Department of Organic and Pharmaceutical Technologies, Odessa National Polytechnic University, Odessa, 65044, Ukraine
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Wang J, Shi G, Yao J, Sheng N, Cui R, Su Z, Guo Y, Dai J. Perfluoropolyether carboxylic acids (novel alternatives to PFOA) impair zebrafish posterior swim bladder development via thyroid hormone disruption. Environ Int 2020; 134:105317. [PMID: 31733528 DOI: 10.1016/j.envint.2019.105317] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/07/2019] [Accepted: 11/06/2019] [Indexed: 05/26/2023]
Abstract
Perfluoropolyether carboxylic acids (PFECAs, CF3(OCF2)nCOO-, n = 2-5) are novel alternatives to perfluorooctanoic acid (PFOA) and are widely used in industrial production. However, although they have been detected in surface water and human blood, their toxicities on aquatic organisms remain unknown. We used zebrafish embryos to compare the developmental toxicities of various PFECAs (e.g., perfluoro (3,5,7-trioxaoctanoic) acid (PFO3OA), perfluoro (3,5,7,9-tetraoxadecanoic) acid (PFO4DA), and perfluoro (3,5,7,9,11-pentaoxadodecanoic) acid (PFO5DoDA)) with that of PFOA and to further reveal the key events related to toxicity caused by these chemicals. Results showed that, based on half maximal effective concentrations (EC50), toxicity increased in the order: PFO5DoDA > PFO4DA > PFOA > PFO3OA, with uninflated posterior swim bladders the most frequently observed malformation. Similar to PFOA, PFECA exposure significantly lowered thyroid hormone (TH) levels (e.g., T3 (3,5,3'-L-triiodothyronine) and T4 (L-thyroxine)) in the whole body of larvae at 5 d post-fertilization following disrupted TH metabolism. In addition, the transcription of UDP glucuronosyltransferase 1 family a, b (ugt1ab), a gene related to TH metabolism, increased dose-dependently. Exogeneous T3 or T4 supplementation partly rescued PFECA-induced posterior swim bladder malformation. Our results further suggested that PFECAs primarily damaged the swim bladder mesothelium during early development. This study is the first to report on novel emerging PFECAs as thyroid disruptors causing swim bladder malformation. Furthermore, given that PFECA toxicity increased with backbone OCF2 moieties, they may not be safer alternatives to PFOA.
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Affiliation(s)
- Jinxing Wang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Guohui Shi
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jingzhi Yao
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Nan Sheng
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ruina Cui
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhaoben Su
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yong Guo
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jiayin Dai
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
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Wan X, Yao G, Liu Y, Chen J, Jiang H. Research Progress in the Biosynthetic Mechanisms of Marine Polyether Toxins. Mar Drugs 2019; 17:E594. [PMID: 31652489 PMCID: PMC6835853 DOI: 10.3390/md17100594] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/17/2019] [Accepted: 10/18/2019] [Indexed: 12/28/2022] Open
Abstract
Marine polyether toxins, mainly produced by marine dinoflagellates, are novel, complex, and diverse natural products with extensive toxicological and pharmacological effects. Owing to their harmful effects during outbreaks of marine red tides, as well as their potential value for the development of new drugs, marine polyether toxins have been extensively studied, in terms of toxicology, pharmacology, detection, and analysis, structural identification, as well as their biosynthetic mechanisms. Although the biosynthetic mechanisms of marine polyether toxins are still unclear, certain progress has been made. In this review, research progress and current knowledge on the biosynthetic mechanisms of polyether toxins are summarized, including the mechanisms of carbon skeleton deletion, pendant alkylation, and polyether ring formation, along with providing a summary of mined biosynthesis-related genes. Finally, future research directions and applications of marine polyether toxins are discussed.
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Affiliation(s)
- Xiukun Wan
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Ge Yao
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Yanli Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Jisheng Chen
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Hui Jiang
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
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Béranger R, Garlantézec R, Le Maner-Idrissi G, Lacroix A, Rouget F, Trowbridge J, Warembourg C, Monfort C, Le Gléau F, Jourdin M, Multigner L, Cordier S, Chevrier C. Prenatal Exposure to Glycol Ethers and Neurocognitive Abilities in 6-Year-Old Children: The PELAGIE Cohort Study. Environ Health Perspect 2017; 125:684-690. [PMID: 27740510 PMCID: PMC5381990 DOI: 10.1289/ehp39] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 09/26/2016] [Accepted: 09/26/2016] [Indexed: 05/25/2023]
Abstract
BACKGROUND Glycol ethers (GE) are widely used organic solvents. Despite the potential neurotoxicity of several families of organic solvents, little is known about the impact of GE on the neurodevelopment of infants and children. OBJECTIVES We investigated the relation between urinary concentrations of GE metabolites in pregnant women and neurocognitive abilities in their 6-year-old children in the PELAGIE mother-child cohort. METHODS Five GE metabolites were measured in first morning void urine samples of 204 French pregnant women in early pregnancy (< 19 weeks of gestation). Psychologists assessed the neurocognitive abilities of their 6-year-old children with the Wechsler Intelligence Scale for Children IV (WISC) and the Developmental Neuropsychological Assessment (NEPSY). We analyzed the results with linear (WISC) and Poisson regression models (NEPSY), adjusted for potential confounders, including child's stimulation at home. RESULTS GE metabolites were detected in 90-100% of maternal urine samples. The WISC Verbal Comprehension score was significantly lower for children with the highest tertile of urinary phenoxyacetic acid (PhAA) [β (third vs. first tertile) = -6.53; 95% CI: -11.44, -1.62]. Similarly, the NEPSY Design Copying subtest score was lower in those with the highest tertile of urinary ethoxyacetic acid (EAA) [β (third vs. first tertile) = -0.11; 95% CI: -0.21, 0.00]. The other GE metabolites we studied were not significantly associated with WISC or NEPSY scores. CONCLUSIONS Prenatal urine concentrations of two GE metabolites were associated with lower WISC Verbal Comprehension Index scores and NEPSY Design Copying subscale scores, respectively, at age 6 years. PhAA is the primary metabolite of 2-phenoxyethanol (EGPhE), which is commonly found in cosmetics, and precursors of EAA are frequently used in cleaning agents. Additional research is needed to confirm our findings and further explore potential effects of prenatal GE exposures on neurocognitive performance in children.
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Affiliation(s)
- Rémi Béranger
- INSERM (Institut national de la santé et de la recherche médicale) U1085-IRSET, University Rennes 1, Rennes, France
| | - Ronan Garlantézec
- INSERM (Institut national de la santé et de la recherche médicale) U1085-IRSET, University Rennes 1, Rennes, France
- University Hospital Rennes, Rennes, France
| | - Gaïd Le Maner-Idrissi
- Research Centre for Psychology, Cognition and Communication (CRPCC EA 1285), University of Rennes 2, Rennes, France
| | - Agnès Lacroix
- Research Centre for Psychology, Cognition and Communication (CRPCC EA 1285), University of Rennes 2, Rennes, France
| | - Florence Rouget
- INSERM (Institut national de la santé et de la recherche médicale) U1085-IRSET, University Rennes 1, Rennes, France
- Department of Pediatrics, Rennes University Hospital, Rennes, France
| | - Jessica Trowbridge
- INSERM (Institut national de la santé et de la recherche médicale) U1085-IRSET, University Rennes 1, Rennes, France
| | - Charline Warembourg
- INSERM (Institut national de la santé et de la recherche médicale) U1085-IRSET, University Rennes 1, Rennes, France
| | - Christine Monfort
- INSERM (Institut national de la santé et de la recherche médicale) U1085-IRSET, University Rennes 1, Rennes, France
| | - Florent Le Gléau
- LABOCEA (Laboratoire public Conseil, Expertise et Analyse), Plouzané, France
| | - Marylène Jourdin
- LABOCEA (Laboratoire public Conseil, Expertise et Analyse), Plouzané, France
| | - Luc Multigner
- INSERM (Institut national de la santé et de la recherche médicale) U1085-IRSET, University Rennes 1, Rennes, France
| | - Sylvaine Cordier
- INSERM (Institut national de la santé et de la recherche médicale) U1085-IRSET, University Rennes 1, Rennes, France
| | - Cécile Chevrier
- INSERM (Institut national de la santé et de la recherche médicale) U1085-IRSET, University Rennes 1, Rennes, France
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Azuma K, Endo G, Endo Y, Hara K, Harada K, Hori H, Horie S, Horiguchi H, Ichiba M, Ichihara G, Ikeda M, Ishitake T, Ito A, Iwasawa S, Kamijima M, Karita K, Kawai T, Kawamoto T, Koizumi A, Kumagai S, Kusaka Y, Miyagawa M, Morimoto Y, Nagano K, Nasu T, Nomiyama T, Omae K, Sato K, Okuda H, Sakurai H, Sobue T, Suwazono Y, Takebayashi T, Takeshita T, Takeuchi A, Tanaka M, Tanaka S, Tsukahara T, Tsunoda M, Ueno S, Yamano Y, Yamauchi T, Yano E. Occupational Exposure Limits of lead, dimethylamine, n-butyl-2,3-epoxypropyl ether, and 2-ethyl-1-hexanol and carcinogenicity and occupational sensitizer classification. J Occup Health 2016; 58:385-7. [PMID: 27476813 PMCID: PMC5356935 DOI: 10.1539/joh.16-0155-op] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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10
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Wang Z, Cousins IT, Scheringer M, Hungerbuehler K. Hazard assessment of fluorinated alternatives to long-chain perfluoroalkyl acids (PFAAs) and their precursors: status quo, ongoing challenges and possible solutions. Environ Int 2015; 75:172-9. [PMID: 25461427 DOI: 10.1016/j.envint.2014.11.013] [Citation(s) in RCA: 335] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 11/13/2014] [Accepted: 11/18/2014] [Indexed: 05/19/2023]
Abstract
Because of concerns over the impact of long-chain perfluoroalkyl acids (PFAAs) on humans and the environment, PFAAs and their precursors are being substituted by alternative substances including fluorinated alternatives that are structurally similar to the substances they replace. Using publicly accessible information, we aimed to identify the status quo of the hazard assessment of identified fluorinated alternatives, to analyze possible systemic shortcomings of the current industrial transition to alternative substances, and to outline possible solutions. Fluorinated alternatives, particularly short-chain PFAAs and perfluoroether carboxylic and sulfonic acids (PFECAs and PFESAs), possess high environmental stability and mobility implying that they have a high global contamination potential. In addition to their potential for causing global exposures, certain fluorinated alternatives have been identified as toxic and are thus likely to pose global risks to humans and the environment. Various factors, particularly the information asymmetry between industry and other stakeholders, have contributed to the current lack of knowledge about the risks posed by fluorinated alternatives. Available cases show that a non-fluorinated substitution strategy (employing either chemical or functionality substitutions) can be a possible long-term, sustainable solution and needs to be further developed and assessed.
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Affiliation(s)
- Zhanyun Wang
- Institute for Chemical and Bioengineering, ETH Zurich, CH-8093 Zurich, Switzerland.
| | - Ian T Cousins
- Department of Applied Environmental Science (ITM), Stockholm University, SE-10691 Stockholm, Sweden
| | - Martin Scheringer
- Institute for Chemical and Bioengineering, ETH Zurich, CH-8093 Zurich, Switzerland; Institute of Sustainable and Environmental Chemistry, Leuphana University Lüneburg, D-21335 Lüneburg, Germany
| | - Konrad Hungerbuehler
- Institute for Chemical and Bioengineering, ETH Zurich, CH-8093 Zurich, Switzerland
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Terasaki M, Yasuda M, Shimoi K, Jozuka K, Makino M, Shiraishi F, Nakajima D. Evaluation of sensitizers found in wastewater from paper recycling areas, and their activation of the aryl hydrocarbon receptor in vitro. Sci Total Environ 2014; 493:156-161. [PMID: 24950494 DOI: 10.1016/j.scitotenv.2014.05.144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/29/2014] [Accepted: 05/30/2014] [Indexed: 06/03/2023]
Abstract
The in vitro potential of sensitizers and related compounds (SRCs) originating from impurities in waste paper in activating the human aryl hydrocarbon receptor (AhR) α was assessed using yeast reporter gene as well as cytochrome P450 (CYP)1A1 and ethoxyresorufin O-deethylase (EROD) assays. In the yeast assay, eight compounds exhibited agonist activity, and their activity relative to β-naphthoflavone (BNF) ranged from 1.4 × 10(-4) to 8.3 × 10(-2), with the highest activity observed for benzyl 2-naphthyl ether (BNE). In the EROD assay, six compounds caused a more significant induction of CYP1A-dependent activity than did the vehicle control at 50 μM (p<0.01), and their induction levels were 5.1- to 11-fold more potent; 1,2-bis(3-methylphenoxy)ethane (BME) was the most effective inducer. The water from the waste paper recycling area was fractioned using solid-phase extraction (SPE) combined with a C18 disk and florisil cartridge. In gas chromatography-mass spectrometry (GC-MS) analysis, SRCs were detected in the first fraction, at a total concentration of 5.5 μg/L. This fraction also activated AhR, and its activity, expressed as a BNF equivalent value, was 0.42 nM in the yeast assay. The contribution ratio of active compounds accounted for up to 34% and 4.4% observed activity of the fraction and total samples, respectively. To our knowledge, this is the first study to show that paper industry-related compounds, namely aromatic sensitizers, activate AhR by using a yeast assay and HepG2 cells.
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Affiliation(s)
- Masanori Terasaki
- Institute for Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
| | - Michiko Yasuda
- Institute for Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Kayoko Shimoi
- Institute for Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Kazuhiko Jozuka
- Institute for Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Masakazu Makino
- Institute for Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Fujio Shiraishi
- Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Daisuke Nakajima
- Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
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12
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Bergeron RJ, Wiegand J, Bharti N, McManis JS. Substituent effects on desferrithiocin and desferrithiocin analogue iron-clearing and toxicity profiles. J Med Chem 2012; 55:7090-103. [PMID: 22889170 PMCID: PMC3583384 DOI: 10.1021/jm300509y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Desferrithiocin (DFT, 1) is a very efficient iron chelator when given orally. However, it is severely nephrotoxic. Structure-activity studies with 1 demonstrated that removal of the aromatic nitrogen to provide desazadesferrithiocin (DADFT, 2) and introduction of either a hydroxyl group or a polyether fragment onto the aromatic ring resulted in orally active iron chelators that were much less toxic than 1. The purpose of the current study was to determine if a comparable reduction in renal toxicity could be achieved by performing the same structural manipulations on 1 itself. Accordingly, three DFT analogues were synthesized. The iron-clearing efficiency and ferrokinetics were evaluated in rats and primates; toxicity assessments were carried out in rodents. The resulting DFT ligands demonstrated a reduction in toxicity that was equivalent to that of the DADFT analogues and presented with excellent iron-clearing properties.
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Affiliation(s)
- Raymond J Bergeron
- Department of Medicinal Chemistry, University of Florida, Box 100485 JHMHC, Gainesville, Florida 32610-0485, USA.
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13
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Abstract
In recent years, the designer nature of ionic liquids (ILs) has driven their exploration and exploitation in countless fields among the physical and chemical sciences. A fair measure of the tremendous attention placed on these fluids has been attributed to their inherent designer nature. And yet, there are relatively few examples of reviews that emphasize this vital aspect in an exhaustive or meaningful way. In this critical review, we systematically survey the physicochemical properties of the collective library of ether- and alcohol-functionalized ILs, highlighting the impact of ionic structure on features such as viscosity, phase behavior/transitions, density, thermostability, electrochemical properties, and polarity (e.g. hydrophilicity, hydrogen bonding capability). In the latter portions of this review, we emphasize the attractive applications of these functionalized ILs across a range of disciplines, including their use as electrolytes or functional fluids for electrochemistry, extractions, biphasic systems, gas separations, carbon capture, carbohydrate dissolution (particularly, the (ligno)celluloses), polymer chemistry, antimicrobial and antielectrostatic agents, organic synthesis, biomolecular stabilization and activation, and nanoscience. Finally, this review discusses anion-functionalized ILs, including sulfur- and oxygen-functionalized analogs, as well as choline-based deep eutectic solvents (DESs), an emerging class of fluids which can be sensibly categorized as semi-molecular cousins to the IL. Finally, the toxicity and biodegradability of ether- and alcohol-functionalized ILs are discussed and cautiously evaluated in light of recent reports. By carefully summarizing literature examples on the properties and applications of oxy-functional designer ILs up till now, it is our intent that this review offers a barometer for gauging future advances in the field as well as a trigger to spur further contemplation of these seemingly inexhaustible and--relative to their potential--virtually untouched fluids. It is abundantly clear that these remarkable fluidic materials are here to stay, just as certain design rules are slowly beginning to emerge. However, in fairness, serendipity also still plays an undeniable role, highlighting the need for both expanded in silico studies and a beacon to attract bright, young researchers to the field (406 references).
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Affiliation(s)
- Shaokun Tang
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, China
| | - Gary A. Baker
- Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211, USA
| | - Hua Zhao
- Chemistry Program, Savannah State University, Savannah, GA 31404, USA
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14
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Abstract
A cinnamic acid ester, two dihydrocinnamic acid esters, a noroxyneolignan, a dibenzyl ether derivative, along with common aromatic compounds and flavonoids were isolated from the extracts of fresh leaves and twigs of Oxalis pes-caprae. The structures of these aromatic compounds were elucidated on the basis of spectroscopic analyses, especially 2D-NMR techniques. Their effects on the germination and growth of Lactuca sativa L. as standard target species have been studied at concentrations ranging from 10(-4) to 10(-7) M. The activities of some compounds were higher than that of pendimethalin, a commercial pre-emergence herbicide.
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Affiliation(s)
- Marina DellaGreca
- UDR Napoli 4 (Consorzio INCA), Dipartimento di Chimica Organica e Biochimica, Università Federico II, Complesso Universitario Monte Sant'Angelo, Via Cinthia 4, I-80126 Napoli.
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15
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Tsai WT. Environmental risk assessment of hydrofluoropolyethers (HFPEs). J Hazard Mater 2007; 139:185-92. [PMID: 17118547 DOI: 10.1016/j.jhazmat.2006.10.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2006] [Revised: 10/05/2006] [Accepted: 10/06/2006] [Indexed: 05/12/2023]
Abstract
Hydrofluoropolyethers (HFPEs), a new family of linear oligomeric fluorinated fluids, are being used as potential replacements for halon, hydrochlorofluorocarbons (HCFCs) and perfluorocarbons (PFCs) that have been listed as ozone depleting substances and/or greenhouse gases. Because of their physicochemical properties, these substances may be industrially used as cleaning solvents in the electronic components, fire suppression agents in the fire protection, and heat transfer fluids in the heat exchangers. From the environmental, ecological, and healthy points of view, it is urgent to understand their environmental risks of these HFPEs. This article aimed at introducing these HFPEs in physiochemical properties and potential uses, and evaluating their environmental risks (i.e., global warming, photochemical potential, and environmental partition). Further, the updated data on their toxicological profiles and potential exposure hazards from their degradation products were also addressed in this paper. It is indicated that HFPEs still pose some significant hazards, especially global warming and photochemical potentials, to the atmosphere. Regarding the estimation of partition properties (i.e., vapor pressure, octanol-water partition coefficient and bioconcentration) of HFPEs, the predicted values of logKow for several HFPEs were found to be below zero, suggesting that they should possess very low potential for bioaccumulation in the environment.
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Affiliation(s)
- Wen-Tien Tsai
- Graduate Institute of Bioresources, National Pingtung University of Science and Technology, Pingtung 912, Taiwan.
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16
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Thuresson K, Bergman K, Rothenbacher K, Herrmann T, Sjölin S, Hagmar L, Päpke O, Jakobsson K. Polybrominated diphenyl ether exposure to electronics recycling workers--a follow up study. Chemosphere 2006; 64:1855-61. [PMID: 16524616 DOI: 10.1016/j.chemosphere.2006.01.055] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2005] [Revised: 01/23/2006] [Accepted: 01/23/2006] [Indexed: 05/07/2023]
Abstract
Workers at an electronics recycling plant have previously been shown to have elevated serum levels of polybrominated diphenyl ethers (PBDEs) compared to referents without occupational PBDE exposure. Subsequent structural changes and industrial hygiene measures at the plant were applied to improve the work environment. The present study aims to assess the impact of these work environment changes on the occupational exposure to PBDEs. Blood were drawn from the workers and analyzed at two different laboratories, and serum concentrations of several PBDE congeners were determined by GC/MS or GC/HRMS. Cross-sectional studies were performed prior to (in 1997; N=19) and after (in 2000; N=27) workplace improvements. Longitudinal studies were performed on twelve of the workers that were sampled at both occasions. Even though the amount of processed goods had doubled in 2000 as compared to 1997, there was a significant decrease in the serum levels of BDE-183 and BDE-209. For BDE-209 the levels observed in year 2000 were even lower than in referents with no occupational exposure. In contrast to the decrease of higher brominated diphenyl ethers, the concentrations of BDE-47 did not significantly change. For BDE-153, the cross-sectional study indicated no change, whereas the longitudinal follow up indicated a significant increase. This study shows that the industrial hygiene improvements clearly reduced the occupational exposure to BDE-183 and BDE-209 at the plant. Still, the levels of hexa- to nonaBDEs but not BDE-209 were elevated, compared to referents with no occupational exposure.
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Affiliation(s)
- Kaj Thuresson
- Department of Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden
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17
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Bergeron RJ, Wiegand J, McManis JS, Vinson JRT, Yao H, Bharti N, Rocca JR. (S)-4,5-dihydro-2-(2-hydroxy-4-hydroxyphenyl)-4-methyl-4-thiazolecarboxylic acid polyethers: a solution to nephrotoxicity. J Med Chem 2006; 49:2772-83. [PMID: 16640338 PMCID: PMC2547084 DOI: 10.1021/jm0508944] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Previous studies revealed that within a family of ligands the more lipophilic chelators have better iron-clearing efficiency. The larger the log P(app) value of the compound, the better the iron-clearing efficiency. What is also clear from the data is that although the relative effects of log P(app) changes are essentially the same through different families, there are differences in absolute value between families. However, there also exists a second, albeit somewhat more disturbing, relationship. In all sets of ligands, the most lipophilic chelator is always the most toxic. The current study focuses on designing ligands that balance the lipophilicity/toxicity problem while iron-clearing efficiency is maintained. Earlier studies with (S)-4,5-dihydro-2-(2-hydroxy-4-methoxyphenyl)-4-methyl-4-thiazolecarboxylic acid [(S)-4'-(CH(3)O)-DADFT, 6] indicated that this methyl ether was a ligand with excellent iron-clearing efficiency in both rodents and primates; however, it was too toxic. On the basis of this finding, a less lipophilic, more water-soluble ligand than 6 was assembled, (S)-4,5-dihydro-2-[2-hydroxy-4-(3,6,9-trioxadecyloxy)phenyl]-4-methyl-4-thiazolecarboxylic acid [(S)-4'-(HO)-DADFT-PE, 11], a polyether analogue, along with its ethyl and isopropyl esters. The parent polyether and its isopropyl and ethyl esters were all shown to be highly efficient iron chelators in both rodents and primates. A comparison of 11 in rodents with the desferrithiocin analogue (S)-4,5-dihydro-2-(2,4-dihydroxyphenyl)-4-methyl-4-thiazolecarboxylic acid [(S)-4'-(HO)-DADFT, 1] revealed the polyether to be more tolerable, achieving higher concentrations in the liver and significantly lower concentrations in the kidney. The lower renal drug levels are in keeping with the profound difference in the architectural changes seen in the kidney of rodents given 1 versus those treated with 11.
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Affiliation(s)
- Raymond J Bergeron
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida 32610-0485, USA.
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18
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Abstract
The CROMRsel procedure was used to model the toxicity of aliphatic ethers against mice. The best model obtained is based on three molecular descriptors and is a better model than other QSAR models from the literature. The only comparable model is one by Ren, based on four descriptors.
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Affiliation(s)
- Ante Milicević
- The Institute of Medical Research and Occupational Health, Zagreb, Croatia
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19
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Zou HB, Gong JX, Li HB, Yang LX, Hu LH, Zhou CX, Wu XM, Dou H, Zhao Y. Total synthesis and cytotoxicity evaluation of syrinenin-4-O-farnesylether and its analogues. J Asian Nat Prod Res 2006; 8:173-9. [PMID: 16753801 DOI: 10.1080/1028602042000325636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
First synthesis of natural product, syrinenin-4-O-farnesylether (1), was carried out via two different paths. Four of its derivatives (9-12) were also prepared. Cytotoxicity screening of the selected compounds were performed on six tumour cell lines. Compound 12 exhibited prominent IC50 values of 1.9 microM and 0.8 microM on CNE and PC-3 cells, respectively.
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Affiliation(s)
- Hong-Bin Zou
- Department of Traditional Chinese Medicine and Natural Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310031, China
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20
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Kharasch ED, Schroeder JL, Bammler T, Beyer R, Srinouanprachanh S. Gene expression profiling of nephrotoxicity from the sevoflurane degradation product fluoromethyl-2,2-difluoro-1-(trifluoromethyl)vinyl ether ("compound A") in rats. Toxicol Sci 2005; 90:419-31. [PMID: 16384817 DOI: 10.1093/toxsci/kfj088] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The major degradation product of the volatile anesthetic sevoflurane, the haloalkene fluoromethyl-2,2-difluoro-1-(trifluoromethyl)vinyl ether (FDVE or "compound A"), is nephrotoxic in rats. FDVE undergoes complex metabolism and bioactivation, which mediates the nephrotoxicity. Nevertheless, the molecular and cellular mechanisms of FDVE toxification are unknown. This investigation evaluated the gene expression profile of kidneys in rats administered a nephrotoxic dose of FDVE. Male Fischer 344 rats (five per group) received 0.25 mmol/kg intraperitoneal FDVE or corn oil (controls) and were sacrificed after 24 or 72 h. Urine output and kidney histological changes were quantified. Kidney RNA was extracted for microarray analysis using Affymetrix GeneChip Rat Expression Array 230A arrays. Quantitative real-time PCR confirmed the modulation of several genes. FDVE caused significant diuresis and necrosis at 24 h, with normal urine output and evidence of tubular regeneration at 72 h. There were 517 informative genes that were differentially expressed >1.5-fold (p < 0.05) versus control at 24 h, of which 283 and 234 were upregulated and downregulated, respectively. Major classes of upregulated genes included those involved in apoptosis, oxidative stress, and inflammatory response (mostly at 24 h), and regeneration and repair; downregulated genes were generally associated with transporters and intermediary metabolism. Among the quantitatively most upregulated genes were kidney injury molecule, osteopontin, clusterin, tissue inhibitor of metalloproteinase 1, and TNF receptor 12, which have been associated with other forms of nephrotoxicity, and angiopoietin-like protein 4, glycoprotein nmb, ubiquitin hydrolase, and HSP70. Microarray results were confirmed by quantitative real-time PCR. FDVE causes rapid and brisk changes in gene expression, providing potential insights into the mechanism of FDVE toxification, and potential biomarkers for FDVE nephrotoxicity which are more sensitive than conventional measures of renal function.
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Affiliation(s)
- Evan D Kharasch
- Department of Anesthesiology, Washington University, St. Louis, Missouri 63110-1093, USA.
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21
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Abstract
Background
The sevoflurane degradation product compound A is nephrotoxic in rats. In contrast, patient exposure to compound A during sevoflurane anesthesia has no clinically significant renal effects. The mechanism for this difference is incompletely understood. One possibility is that the metabolism and toxicity of compound A in humans is prevented by sevoflurane. However, the effect of sevoflurane on compound A metabolism and nephrotoxicity is unknown. Thus, the purpose of this investigation was to determine the effect of sevoflurane on the metabolism and renal toxicity of compound A in rats.
Methods
Male rats received 0.25 mmol/kg intraperitoneal compound A, alone and during sevoflurane anesthesia (3%, 1.3 minimum alveolar concentration, for 3 h). Compound A metabolites in urine were quantified, and renal function was evaluated by serum creatinine and urea nitrogen, urine volume, osmolality, protein excretion, and renal tubular histology.
Results
Sevoflurane coadministration with compound A inhibited compound A defluorination while increasing relative metabolism through pathways of sulfoxidation and beta-lyase-catalyzed metabolism, which mediate toxicity. Sevoflurane coadministration with compound A increased some (serum creatinine and urea nitrogen, and necrosis) but not other (urine volume, osmolality, and protein excretion) indices of renal toxicity.
Conclusions
Sevoflurane does not suppress compound A nephrotoxicity in rats in vivo. These results do not suggest that lack of nephrotoxicity in surgical patients exposed to compound A during sevoflurane anesthesia results from an inhibitory effect of sevoflurane on compound A metabolism and toxicity. Rather, these results are consistent with differences between rats and humans in compound A exposure and inherent susceptibility to compound A nephrotoxicity.
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Affiliation(s)
- Evan D Kharasch
- Department of Anesthesiology, University of Washington, Seattle, WA, USA.
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22
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Poon R, Wade M, Valli VE, Chu I. Short-term oral toxicity of butyl ether, ethyl hexyl ether, methyl heptyl ether and 1,6-dimethoxyhexane in male rats and the role of 2-methoxyacetic acid. Toxicology 2005; 214:99-112. [PMID: 16061321 DOI: 10.1016/j.tox.2005.06.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Revised: 06/06/2005] [Accepted: 06/13/2005] [Indexed: 01/18/2023]
Abstract
A 4-week oral study was conducted in male rats to characterize and compare the toxicity of four aliphatic ethers (butyl ether, BE; ethyl hexyl ether, EHxE; methyl heptyl ether, MHpE; and 1,6-dimethoxyhexane, DMH) which have been proposed as high-cetane diesel additives. Male Sprague-Dawley rats (280+/-20 g) were divided into groups of seven animals each and were administered by gavage low (2mg/kg body weight), medium (20mg/kg) or high (200mg/kg) doses of BE, EHxE, or MHpE, 5 days per week for 4 weeks. Another group of animals was administered DMH at 200mg/kg while the control group received the vehicle (corn oil at 1 ml/100g bw) only. At the end of the treatment period, relative testis weights and thymus weights were significantly decreased in the DMH group but not in animals receiving BE, EHxE, or MHpE. Microscopic examination revealed degeneration of the seminiferous tubules and reduction of sperm density in the epididymides in the DMH treatment group. Urinary creatine/creatinine ratio, a sensitive indicator of testicular damage, was markedly elevated in the DMH treated animals but not in those treated with BE, EHxE, or MHpE. In the bone marrow, DMH caused mild dyserythropoiesis and dysthrombopoiesis, while BE, EHxE, and MHpE produced mild increases in granulocytes and myelocyte/erythrocyte ratio. All four ethers at 200mg/kg caused mild histological changes in the thyroid but no significant modulation in the circulating thyroxin (T4) or triiodothyronine (T3) levels. All four ethers produced hepatic effects at 200mg/kg consisting of mild, adaptive histological changes, increased urinary ascorbic acid output, and elevation in the activities of one or more xenobiotic metabolizing enzymes (benzyloxyresorufin-O-dealkylase, UDP-glucuronosyltransferase, glutathione-S-transferases). The level of 2-methoxyacetic acid (MAA), a known testicular and developmental toxin, was significantly increased in the urine and plasma of animals treated with DMH but not in those administered the high dose BE, EHxE, or MHpE. Amomg the individual rats treated with DMH, the MAA level appeared to correlate with the severity of toxicity such as testicular and thymic weights, and urinary creatine/creatinine ratio. It is concluded that BE, EHxE, and MHpE differed from DMH in that they did not produce testicular or thymic toxicity. All four ethers at high dose caused changes to the thyroid, liver and bone marrows that were mild and adaptive in nature. MAA appeared to be the proximal toxicant in DMH treated animals but the route by which DMH is metabolized to MAA remains to be elucidated.
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Affiliation(s)
- Raymond Poon
- Environmental Health Science Bureau, Health Canada, Ottawa, Ont., Canada K1A 0L2.
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23
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Abstract
Bioassay-guided purification of the organic crude extract of Alternaria solani resulted in the isolation of three metabolites responsible for causing necrosis on potato leaves. These phytotoxins were identified as 2-(2",3"-dimethyl-but-1-enyl)-zinniol (1), 8-zinniol methyl ether (2). and 8-zinniol methyl ether based on their spectroscopic data (IR, MS, 1H and 13CNMR). Metabolites 1 and 2 have been identified as new phytotoxins structurally related to zinniol (4). Additionally, 5-(3',3'-dimethylallyloxy)-7-methoxy-6-methyl-phthalide and 8-zinniol-2-(phenyl)-ethyl ether (3) were also isolated during the purification process.
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Affiliation(s)
- Jorge Moreno-Escobar
- Grupo de Química Orgánica, Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130, col. Chuburná, Mérida, Yucatán, Mexico
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24
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Wang Y, Liu H, Zhao C, Liu H, Cai Z, Jiang G. Quantitative structure-activity relationship models for prediction of the toxicity of polybrominated diphenyl ether congeners. Environ Sci Technol 2005; 39:4961-6. [PMID: 16053097 DOI: 10.1021/es050017n] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Levels of polybrominated diphenyl ethers (PBDEs) are increasing in the environment and may cause long-term health problems in humans. The similarity in the chemical structures of PBDEs and other halogenated aromatic pollutants hints on the possibility that they might share similar toxicological effects. In this work, three-dimensional quantitative structure activity relationships (3-D-QSAR) models, using comparative molecular field analysis (CoMFA) and comparative similarity indices analysis (CoMSIA), were built based on calculated structural indices and a reported experimental toxicology index (aryl hydrocarbon receptor relative binding affinities, RBA) of 18 PBDEs congeners, to determine the factors required for the RBA of these PBDEs. After performing leave-one-out cross-validation, satisfactory results were obtained with cross-validation O2 and R2 values of 0.580 and 0.995 by the CoMFA model and 0.680 and 0.982 by the CoMSIA model, respectively. The results showed clearly that the nonplanar conformations of PBDEs result in the lowest energy level and that the electrostatic index was the main factor reflecting the RBA of PBDEs. The two QSAR models were then used to predict the RBA value of 46 PBDEs for which experimental values are unavailable at present.
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Affiliation(s)
- Yawei Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Graduate School of Chinese Academy of Sciences, Beijing, 100085, China
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25
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Abstract
The use of glycol ethers has changed significantly over the past 30 years. Low molecular weight E-series have been phased-out and progressively replaced by low molecular weight P-series whenever possible. There is a trend to shift from E-series to P-series and an obvious willingness to substitute where alternative solutions exist or as a consequence of strengthening regulation and voluntary measures to reduce exposure in the workplace.
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Affiliation(s)
- P de Ketttenis
- Oxygenated Solvents Producers Association, CEFIC, 4 Avenue Van Nieuwenhuyse, B-1160 Brussels, Belgium.
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26
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Gift JS. U.S. EPA's IRIS assessment of 2-butoxyethanol: the relationship of noncancer to cancer effects. Toxicol Lett 2005; 156:163-78. [PMID: 15705494 DOI: 10.1016/j.toxlet.2003.08.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2003] [Accepted: 08/14/2003] [Indexed: 11/28/2022]
Abstract
U.S. EPA's integrated risk information system (IRIS) assessment of 2-butoxyethanol (EGBE) indicates that the human carcinogenic potential of EGBE cannot be determined at this time, but that "suggestive evidence" for cancer exists from laboratory animal studies (hemangiosarcoma of the liver in male mice and forestomach squamous cell papilloma or carcinoma in female mice [National Toxicology Program (NTP), 2000a. Toxicology and carcinogenesis studies of 2-butoxyethanol (CAS no. 111-76-2) in F344/N rats and B6C3F1 mice (inhalation studies). National Toxicology Program Technical Report Series No. 484. U.S. Department of Health and Human Services, National Institutes of Health, Washington, DC]). Since the last EGBE IRIS assessment, a number of studies have provided evidence that the carcinogenic effects observed in mice are nonlinear in their mode of action and may be dependent on threshold events such as EGBE-induced hemolytic effects. EPA is in the process of considering several questions relating to this issue. First, can a plausible mode of action be determined for the two types of tumors observed in mice? Second, are the mechanisms involved applicable to humans? If so, should the mode of action be considered to result in a linear or nonlinear dose-response? These questions will be addressed within the context of the agency's new cancer guidelines and with regard to how the answers might affect a revised IRIS assessment for EGBE.
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Affiliation(s)
- J S Gift
- U.S. EPA, National Center for Environment Assessment (MD-B243-01), Research Triangle Park, NC 27711, USA.
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Multigner L, Catala M, Cordier S, Delaforge M, Fenaux P, Garnier R, Rico-Lattes I, Vasseur P. The INSERM expert review on glycol ethers: findings and recommendations. Toxicol Lett 2005; 156:29-37. [PMID: 15705485 DOI: 10.1016/j.toxlet.2003.12.077] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2003] [Accepted: 12/08/2003] [Indexed: 11/16/2022]
Abstract
The use of glycol ethers and their effects on health have recently attracted the attention of the French health authorities. At their request, INSERM, the French Institute of Health and Medical Research, conducted a collective expertise review on glycol ethers in 1999. INSERM Expertise Reviews are independent procedures performed by experts from several disciplines, to guarantee the objectivity and the relevance of the report. During several work sessions, the experts carried out a critical analysis of and reviewed studies concerning the toxicity of glycol ethers. This process resulted in a series of recommendations and conclusions. All these data have been published in the form of a report and have been used to help the public authorities to make decisions on how to prevent risks for professionals and consumers.
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Affiliation(s)
- L Multigner
- INSERM U 625, Campus de Beaulieu, Universite de Rennes 1, 35042 Rennes Cedex, France.
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Abstract
The occupational exposure assessment uses data from published sources, from Industry (most often from the producers), and from dedicated occupational exposure data bases, as well as evaluations using the EASE model (Estimation and Assessment of Substance Exposure). Atmospheric concentrations and characteristics of skin contacts are evaluated in different scenarios (such as manufacturing, formulating, main and most polluting uses) and sub-scenarios (e.g. warm water dilution). Air concentrations of EGBE are low during production (most often <0.5 mg/m(3)), incidental excursions being <50 mg/m(3); the "worst-case" mean concentration is proposed as 9 mg/m(3). Skin contact, according to EASE, may be in the range of 0-0.1 mg/cm(2)(day), and should be mitigated by the use of suitable gloves. For formulations of products containing EGBE, air concentrations are evaluated as 10 mg/m(3) and skin contact as 0.19 mg/cm(2)(day). The "reasonable worst case" air concentrations (8-Hr TWA) are assessed at around 11 mg/m(3) (coating industry), from 5 to 20 mg/m(3) in printing activities (depending on the task), and in the 20-70 mg/m(3) range (upper limit 40 mg/m(3) in better controlled situations) for cleaning activities. Skin contact would be around twice the preceding level, i.e., 0.4 mg/cm(2)(day) for coating as well as cleaning activities. EGBE and its major metabolites, 2-butoxyacetaldehyde (2-BAL) and 2-butoxyacetic acid (2-BAA) have been subjected to tests for genetic toxicity tests both in vitro and in vivo. While some positive responses have been obtained, the balance of the evidence indicates that EGBE does not express significant genotoxic activity. There are no epidemiological data investigating a relationship between exposure to EGBE and human cancer. Two carcinogenicity inhalation bioassays have been conducted in rodents, one in rats and one in mice. Significant increases were found in forestomach tumours in female mice and haemangiosarcomas in male mice. No increases in tumour incidences were found in either male or female rats. Mechanistic studies have suggested the crucial involvement in the pathogenesis of haemangiosarcomas of a chain of events consisting of (1) haemolysis due to BAA, followed by (2) hepatic haemosiderin deposition and (3) the subsequent generation of reactive oxygen species within the endothelial cells from which haemangiosarcomas arise. Since human erythrocytes are particularly resistant to the haemolytic effects of BAA, it is extremely unlikely, according to this model, that the haemangiosarcomas observed in male mice will have human significance. Similarly, mechanistic studies on the female mouse forestomach tumours have suggested that these also are not important as an indication of human risk. In vivo, EGBE tested in a continuous breeding study and in repeated dose toxicity tests, did not produced specific effects on reproductive organs or fertility parameters. For developmental toxicity, rats, mice and rabbits were dosed via oral and/or inhalation routes. Foeto- and embryo-toxicity was observed in presence or maternal toxicity (haemolytic anaemia). The data available give plausible support to the hypothesis that this developmental toxicity is a direct consequence of maternal toxicity. There are no epidemiological data investigating a relationship between exposure to EGBE alone and human reproductive effects.
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Affiliation(s)
- A Fastier
- Institut National de Recherche et de Securite, Chemical and Biological Risks Department, 30 rue Oliver Noyer, 75680 Paris Cedex 14, France.
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Abstract
Propylene glycol ethers are a class of solvents used in a wide array of industrial, commercial and consumer applications, such as in paints, cleaners and inks. A robust toxicity database exists for the propylene glycol ethers that provide strong product safety support. Standard toxicity studies conducted under good laboratory practices indicate a lack of genotoxic, developmental and reproductive hazards. Recent testing efforts have primarily focused in two areas: (1) examination of the chronic toxicity/oncogenicity potential of propylene glycol monomethyl ether (PGME) in rats and mice and (2) expansion of the developmental toxicity database to higher molecular weight P-series glycol ether derivatives (i.e. propylene glycol n-propyl ether (PGPE), propylene glycol n-butyl ether (PGBE) and dipropylene glycol n-butyl ether (DPGBE)). In PGME chronic toxicity/oncogenicity studies no treatment-related increases in the incidence of tumors occurred in either species. Like other previously tested P-series derivatives, PGPE, PGBE and DPGBE were negative in rodent and rabbit developmental toxicity studies. Collectively, the toxicity database for P-series glycol ether products continues to support the lack of significant health effects with proper use of the commercial products.
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Affiliation(s)
- P J Spencer
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, 1803 Building, Midland, MI 48674, USA.
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Lewis S, Tyler T, Kelsey J, Page Waugh K. Proceedings of the Third International Scientific Symposium on the Health Effects of Glycol Ethers – 2002, 17–18 October 2002, Maison De La Chimie Paris, France. Toxicol Lett 2005; 156:1-2. [PMID: 15705482 DOI: 10.1016/j.toxlet.2004.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
Following the recognition in the early 1980s of the potential reproductive hazards of certain glycol ethers, industry organizations were formed in the US and Europe having a number of stated goals to: (1) provide hazard information by expanding the toxicity database for glycol ethers; (2) promote cooperation among scientists, governmental authorities, and industry; and (3) promote scientifically sound regulatory actions and to assist in the setting of scientifically defensible safety standards. This effort led to early recommendations that EGME, EGEE, and their acetates be removed from consumer products. Also, studies conducted by industry under US EPA test rules have led to a better understanding of the hazards associated with glycol ether constituents of brake fluids, paints, and other products. Industry-provided information has greatly assisted the setting of occupational and public safety standards in a number of countries. Hazard assessments for a number of large-volume glycol ethers have been performed under the OECD SIDS program. This work continues with the industry-funded ICCA/HPV testing initiative. To provide sound risk assessment data, industry continues to sponsor basic research aimed at better understanding human versus mouse versus rat sensitivities to certain glycol ethers. Industry has also prepared and supported the publication of toxicological data compendia for glycol ethers.
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Affiliation(s)
- R J Boatman
- Health, Safety, and Environment, Eastman Kodak Company, Rochester, NY 14652, USA.
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Abstract
Glycol ethers are a complex family of more than 30 substances that exhibit a wide range of toxicological properties. This complexity can lead to confusion over which are of real concern and which do not pose significant hazards. Also, many have not been reviewed under the European hazard classification and labelling scheme. Following a major study carried out in France, a number of glycol ethers were identified for review under the classification scheme. This process is now substantially complete and revised classification proposals made and agreed at the European level. When these changes are enacted, the classification of all the commercially important glycol ethers and glymes will reflect their known toxicological hazards.
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Affiliation(s)
- A Laudet-Hesbert
- Institut National de Recherche et de Sécurité, 30 rue Oliver Noyer, 75680 Paris Cedex 14, France.
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Abstract
The tumor-promoting activities of 5 commercial compounds used in termiticides were measured by a cell-transformation assay employing Bhas 42 cells. Their initiating activities were also measured by the microsuspension assay employing S. typhimurium TA98 and TA100 strains. The results of the transformation assay confirmed the tumor-promoting activities of fenitrothion, silafluofen and bifenthrin. Furthermore, the mutagenicity of S-421 and fenitrothion were also confirmed. Consideration of 2-stage carcinogenesis suggests that concurrent use of and long-term exposure to these compounds that have tumor-promoting and initiator activity, and compounds exhibiting either type of activity individually should be avoided as much as possible.
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Affiliation(s)
- Sumio Goto
- Research Center for Material Cycles and Waste Management, National Institute for Environmental Studies, Onogawa, Tsukuba, Ibaraki 305-8506, Japan
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Sheffels P, Schroeder JL, Altuntas TG, Liggitt HD, Kharasch ED. Role of Cytochrome P4503A in Cysteine S-Conjugates Sulfoxidatıon and the Nephrotoxicity of the Sevoflurane Degradatıon Product Fluoromethyl-2,2-difluoro-1-(trifluoromethyl)vinyl Ether (Compound A) in Rats. Chem Res Toxicol 2004; 17:1177-89. [PMID: 15377151 DOI: 10.1021/tx049899e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The volatile anesthetic sevoflurane is degraded to fluoromethyl-2,2-difluoro-1-(trifluoromethyl)vinyl ether (FDVE) in anesthesia machines. FDVE is nephrotoxic in rats. FDVE undergoes glutathione conjugation, subsequent conversion to cysteine and mercapturic acid conjugates, and cysteine conjugate metabolism by renal beta-lyase, which is a bioactivation pathway mediating nephrotoxicity in rats. Recent in vitro studies revealed cytochrome P4503A-catalyzed formation of novel sulfoxide metabolites of FDVE cysteine-S and mercapturic acid conjugates in rat liver and kidney microsomes. FDVE-mercapturic acid sulfoxides were more toxic than other FDVE conjugates to renal proximal tubular cells in culture. Nevertheless, the occurrence and toxicological significance of FDVE sulfoxides formation in vivo remain unknown. This investigation determined, in rats in vivo, the existence, role of P4503A, and nephrotoxic consequence of FDVE conjugates sulfoxidation. Rats were pretreated with dexamethasone, phenobarbital, troleandomycin, or nothing (controls) before FDVE, and then, nephrotoxicity, FDVE-mercapturate sulfoxide urinary excretion, and FDVE-mercapturate sulfoxidation by liver microsomes were assessed. The formation of FDVE-mercapturic acid sulfoxide metabolites in vivo and their urinary excretion were unambiguously established by mass spectrometry. Dexamethasone and phenobarbital increased, and troleandomycin decreased (i) liver microsomal FDVE-mercapturic acid sulfoxidation in vitro, (ii) FDVE-mercapturic acid sulfoxide urinary excretion in vivo, and (iii) FDVE nephrotoxicity in vivo assessed by renal histology, blood urea nitrogen concentrations, and urine volume and protein excretion. Urine 3,3,3-trifluoro-2-(fluoromethoxy)propanoic acid, reflecting beta-lyase-dependent FDVE-cysteine S-conjugates metabolism, was minimally affected by the pretreatments. These results demonstrate that FDVE S-conjugates undergo P4503A-catalyzed sulfoxidation in rats in vivo, and this sulfoxidation pathway contributes to nephrotoxicity. FDVE S-conjugates sulfoxidation constitutes a newly discovered mechanism of FDVE bioactivation and toxicification in rats, in addition to beta-lyase-catalyzed metabolism of FDVE-cysteine S-conjugates.
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Affiliation(s)
- Pam Sheffels
- Department of Anesthesiology, University of Washington, Seattle, Washington 98195-6540, USA
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Andresen TL, Davidsen J, Begtrup M, Mouritsen OG, Jørgensen K. Enzymatic Release of Antitumor Ether Lipids by Specific Phospholipase A2 Activation of Liposome-Forming Prodrugs. J Med Chem 2004; 47:1694-703. [PMID: 15027860 DOI: 10.1021/jm031029r] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An enzymatically activated liposome-based drug-delivery concept involving masked antitumor ether lipids (AELs) has been investigated. This concept takes advantage of the cytotoxic properties of AEL drugs as well as the membrane permeability enhancing properties of these molecules, which can lead to enhanced drug diffusion into cells. Three prodrugs of AELs (proAELs) have been synthesized and four liposome systems, consisting of these proAELs, were investigated for enzymatic degradation by secretory phospholipase A(2) (sPLA(2)), resulting in the release of AELs. The three synthesized proAELs were (R)-1-O-hexadecyl-2-palmitoyl-sn-glycero-3-phosphocholine (1-O-DPPC), (R)-1-O-hexadecyl-2-palmitoyl-sn-glycero-3-phosphoethanolamine poly(ethylene glycol)(350) (1-O-DPPE-PEG(350)), and 1-O-DPPE-PEG(2000) of which 1-O-DPPC was the main liposome component. All three phospholipids were synthesized from the versatile starting material (R)-O-benzyl glycidol. A phosphorylation method, employing methyl dichlorophosphate, was developed and applied in the synthesis of two analogues of (R)-1-O-hexadecyl-2-palmitoyl-sn-glycero-3-phosphoethanolamine poly(ethylene glycol). Differential scanning calorimetry has been used to investigate the phase behavior of the lipid bilayers. A release study, employing calcein encapsulated in non-hydrolyzable 1,2-bis-O-octadecyl-sn-glycero-3-phosphocholine (D-O-SPC) liposomes, showed that proAELs, activated by sPLA(2), perturb membranes because of the detergent-like properties of the released hydrolysis products. A hemolysis investigation was conducted on human red blood cells, and the results demonstrate that proAEL liposomes display a very low hemotoxicity, which has been a major obstacle for using AELs in cancer therapy. The results suggest a possible way of combining a drug-delivery and prodrug concept in a single liposome system. Our investigation of the permeability-enhancing properties of the AEL molecules imply that by encapsulating conventional chemotherapeutic drugs, such as doxorubicin, in liposomes consisting of proAELs, an increased effect of the encapsulated drug might be achievable due to an enhanced transmembrane drug diffusion.
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Affiliation(s)
- Thomas L Andresen
- Department of Chemistry and LiPlasome Pharma A/S, Technical University of Denmark, Building 207, DK-2800 Lyngby, Denmark.
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Abstract
Pentyl ether (PE) and two newly synthesized polyoxy ethers, 1,4-diethoxybutane (DEB) and 1,6-dimethoxyhexane (DMH), have been proposed as candidate diesel fuel additives. To characterize and compare their toxicity and to provide information for risk assessment, a 4-week oral study was conducted on these compounds. Male Sprague-Dawley rats (288 +/- 20 g) were divided into groups of seven animals each, and were administered by gavage low (2 mg/kg body weight), medium (20 mg/kg body weight), or high (200 mg/kg body weight) doses of PE, DEB, or DMH, respectively, 5 days/week for 4 weeks. Animals in the control group received the vehicle (corn oil, 1 ml/100 g body weight) only. At the end of the exposure period, relative testis and thymus weights were reduced by 30 and 46%, respectively, in animals treated with the high dose of DMH. Significant reductions in serum lactate dehydrogenase (LDH), serum uric acid, and blood platelet counts were also observed in the high dose of DMH. Serum corticosterone was significantly depressed in the high doses of PE and DEB and in the low dose of DMH. Serum thiobarbituric acid-reactive substances (TBARS) were decreased (p < 0.05) in all DMH treatment groups and in the medium and high dose PE and DEB groups, while liver TBARS were unaffected by treatment. In the liver, increased glutathione (GSH) level and glutathione-S-transferases activity were detected in the high dose DMH group. Urinary ascorbic acid levels were markedly increased in animals receiving the high doses of PE, DEB, and DMH. Urinary formic acid was increased by 13 times in the high dose PE and DEB groups. Testes of all animals receiving the high dose of DMH showed a moderate to marked degree of degeneration of the seminiferous tubules, including a mild degree of vacuolation. At the same time, the epididymis of these animals had substantially reduced sperm density with prominent presence of spermatid giant cells. Mild histological changes were seen in the liver at all dose levels for all three chemicals. Thyroid effects were also observed in the high dose PE and DEB groups and in the medium and high dose DMH groups. It was concluded that DMH is the most toxic of the three ethers tested, with testicular, epidiymal, and thymic effects being the most prominent at 200 mg/kg. Other significant changes included depressed platelet counts and serum biochemical changes. Increased production of formic acid, an ocular toxin, from PE and DEB treatments may also be of toxicological concern.
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Affiliation(s)
- Raymond Poon
- Environmental Health Science Bureau, Health Canada, Ottawa, Ontario, Canada.
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Altuntas TG, Zager RA, Kharasch ED. Cytotoxicity of S-conjugates of the sevoflurane degradation product fluoromethyl-2,2-difluoro-1-(trifluoromethyl) vinyl ether (Compound A) in a human proximal tubular cell line. Toxicol Appl Pharmacol 2003; 193:55-65. [PMID: 14613716 DOI: 10.1016/s0041-008x(03)00336-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Fluoromethyl-2,2-difluoro-1-(trifluoromethyl)vinyl ether (FDVE) is a fluorinated alkene formed by degradation of the volatile anesthetic sevoflurane in anesthesia machines. FDVE is nephrotoxic in rats but not humans. Rat FDVE nephrotoxicity is attributed to FDVE glutathione conjugation and bioactivation of subsequent FDVE-cysteine S-conjugates, in part by renal beta-lyase. Although FDVE conjugation and metabolism occur in both rats and humans, the mechanism for selective toxicity in rats and lack of effect in humans is incompletely elucidated. This investigation measured FDVE S-conjugate cytotoxicity in cultured human proximal tubular HK-2 cells, and compared this with known cytotoxic S-conjugates. HK-2 cells were incubated with FDVE and its GSH, cysteine S-mercapturic acid, cysteine S-sulfoxide, and mercapturic acid sulfoxide conjugates (0.1-2.7 mM) for 24 h. Cytotoxicity was determined by lactate dehydrogenase (LDH) release, total LDH, and the ability of viable cells to reduce a tetrazolium-based compound (MTT). FDVE was cytotoxic only at concentrations >/=0.9 mM. No increase in LDH release was observed with either FDVE-GSH conjugate. The FDVE-cysteine conjugates S-(1,1-difluoro-2-fluoromethoxy-2-(trifluoromethyl) ethyl)-L-cysteine (DFEC) and (Z)-S-(1-fluoro-2-fluoromethoxy-2-(trifluoromethyl) vinyl)-L-cysteine ((Z)-FFVC) caused significant differences in LDH release and MTT reduction only at 2.7 mM; (Z)-FFVC was slightly more cytotoxic. Both S-(1,1-difluoro-2-fluoromethoxy-2-(trifluoromethyl) ethyl)-L-cysteine sulfoxide (DFEC-SO) and (Z)-N-acetyl-S-(1-fluoro-2-fluoromethoxy-2-(trifluoromethyl) vinyl)-L-cysteine sulfoxide ((Z)-N-Ac-FFVC-SO) caused slightly greater changes in LDH release or total LDH than the corresponding equimolar DFEC and (Z)-N-acetyl-S-(1-fluoro-2-fluoromethoxy-2-(trifluoromethyl) vinyl)-L-cysteine ((Z)-N-Ac-FFVC) conjugates. In contrast to FDVE S-conjugates, S-(1,2-dichlorovinyl)-L-cysteine was markedly cytotoxic, at concentrations as low as 0.1 mM. These results show that human proximal tubular cells are relatively resistant to FDVE and FDVE S-conjugate cytotoxicity. This may partially explain the lack of FDVE nephrotoxicity in humans.
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Affiliation(s)
- T Gul Altuntas
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Ankara University, Ankara, Turkey
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Abstract
The aim of this study was to assess the cytotoxicity of tow types of impression dental materials: polyethers (Impregum Penta, Permadyne Penta Heavy and Light) and vinyl polysiloxanes (Elite Mono Tray, Medium, Low viscosity and Elite H-D Putty). Their cytotoxic effects were studied by indirect and direct tests. The indirect tests were performed by incubating impression materials in serum free cell culture medium to prepare the soluble extracts. Balb/c 3T3 cells were incubated with extract dilutions (25, 50, 75 and 100%) for 24 h. The extracts of polyether materials caused a decrease of cellular viability, evaluated by light microscopy, by cell counting and by MTT test. The extracts of vinyl polysiloxanes materials induced a slight effect on cellular number and viability. The direct tests were performed by placing the impression materials in the centre of Petri dishes while Balb/c 3T3 were settling. The cellular proliferation was drastically reduced by polyethers and it was unaffected by the presence of vinyl polysiloxanes. These results show that: (a) the polyether materials are more toxic than vinyl polysiloxanes in our experimental conditions, (b) the impression materials are cytotoxic to the same degree in all assay methods.
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Affiliation(s)
- Tiozzo Roberta
- Department of Biomedical Sciences, Section of General Pathology, University of Modena and Reggio Emilia, Via G. Campi 287, 4100 Modena, Italy.
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Krieger RI, Dinoff TM, Zhang X. Octachlorodipropyl ether (s-2) mosquito coils are inadequately studied for residential use in Asia and illegal in the United States. Environ Health Perspect 2003; 111:1439-42. [PMID: 12948880 PMCID: PMC1241643 DOI: 10.1289/ehp.6177] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Children and their parents in residences are often protected by insecticides from nuisance and disease-bearing mosquitoes. The annual worldwide consumption of the four major types of residential insecticide products--aerosols, mosquito coils, liquid vaporizers, and vaporizing mats--is in the billions of units. Mosquito coils are burned indoors and outdoors in East Asia and to a limited extent in other parts of the world, including the United States. Coils consist of an insecticide/repellant, organic fillers capable of burning with smoldering, binder, and additives such as synergists, dyes, and fungicide. The number of coil users in China is in the millions. In Indonesia alone, an estimated seven billion coils are purchased annually. Coils containing pyrethroid insecticides, particularly d-allethrin, may contain octachlorodipropyl ether (S-2, S-421) as a synergist or active ingredient. Use of those coils likely exposes children and adults to some level of bis(chloromethyl)ether (BCME). BCME is formed from formaldehyde and hydrogen chloride, combustion products formed from the slow smoldering (about 8 hr/coil) of the mosquito coils. Because BCME is an extremely potent lung carcinogen, the nature and extent of prolonged exposures that recur in homes during the mosquito season in tropical regions must be evaluated with respect to health. In a small analytical study, coils purchased in Indonesia and in the United States contained highly variable amounts of S-2. Some coils that contained S-2 were not labeled, making it impossible for consumers to make an informed decision about coil contents. Mosquito coils containing S-2 are unregistered, and their use is illegal in the United States. Indoor air monitoring under conditions that represent conditions of use in tropical settings and epidemiology to assess health impacts of coil use are essential to permit responsible regulatory decisions regarding continuing S-2 use.
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Affiliation(s)
- Robert I Krieger
- Department of Entomology, Personal Chemical Exposure Program, Graduate Program in Environmental Toxicology, University of California, Riverside, CA 92521, USA.
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Stabernack CR, Eger EI, Warnken UH, Förster H, Hanks DK, Ferrell LD. Sevoflurane degradation by carbon dioxide absorbents may produce more than one nephrotoxic compound in rats. Can J Anaesth 2003; 50:249-52. [PMID: 12620947 DOI: 10.1007/bf03017793] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Degradation of sevoflurane by carbon dioxide absorbents produces compound A, a vinyl ether. In rats, compound A can produce renal corticomedullary necrosis. We tested whether other compounds produced by sevoflurane degradation also could produce corticomedullary necrosis. METHODS Two groups of rats were exposed for four hours to sevoflurane 2.5% delivered through a container filled with fresh Sodasorb and heated to 30 degrees C or to 50 degrees C, respectively. Compound A was added to produce an average concentration of 120 ppm in both groups. A third (control) group received 2.5% sevoflurane that did not pass through absorbent, and no compound A was added. RESULTS As determined by gas chromatography, the higher temperature produced more volatile breakdown products, including compound A. Median necrosis of the corticomedullary junction in the 50 degrees C group [10% (quartiles 1.0%-7.8%); n = 20] exceeded that in the 30 degrees C group [5% (6.5%-15%); n = 18; P < 0.02], and both exceeded the median necrosis in the control group [0% (0.0%-0.2%); n = 10; P < 0.02]. The respective mean +/- SD values for these three studies were: 12.8 +/- 16.7%, 5.3 +/- 4.4%, and 0.3 +/- 0.5%. CONCLUSION Degradation products of sevoflurane other than compound A can cause or augment the renal injury in rats produced by compound A.
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Affiliation(s)
- Caroline R Stabernack
- Department of Anesthesia and Perioperative Care, and the Department of Pathology, University of California, San Francisco 94143, USA
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Matsushima Y, Uchida O, Saitoh M, Kawasaki Y, Isama K, Kaniwa M, Inoue T, Kanno J. [Twenty-eight day repeated dose oral toxicity test of synergist of a pyrethroid insecticide, 2,3,3,3,2',3',3',3'-Octachlorodipropyl ether (S-421) in rats]. Kokuritsu Iyakuhin Shokuhin Eisei Kenkyusho Hokoku 2003:40-7. [PMID: 14740404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
2,3,3,3,2',3',3',3'-Octachlorodipropyl ether (Abbreviation; S-421) is originally developed as synergist of a pyrethroid insecticide. In recent years, S-421 is used widely at home, for a mosquito-repellent incense, electric mosquito-repellent, an insect-killing spray, a vacuum cleaner paper pack, etc. as well. On the other hand, S-421 has been detected in vacuum cleaner dust samples as well as human milk samples in Japan indicating that our living environment is already contaminated by this compound. Long term toxicity studies including a carcinogenesis study have been performed and NOEL of chronic toxicity has been settled. However, it is clear that S-421 is used in close proximity so that acute or subacute exposure at relatively higher dose levels than chronic NOEL values are easily assumed, such as use of a spray in an ill-ventilated room, etc. This study, 28 day repeated oral dose toxicity study of S-421 was performed to monitor the outcome of acute and subacute exposure assuming possible exposure accidents mentioned above. The protocol is as follows; Groups of 10 rats of each sex(5 week-old), were treated with intragastric administration of S-421 with a dose of 0 (olive oil, control), 10, 40, 160 or 640 mg/kg body weight. For recovery test, 14 day after the last treatment, the control and 640 mg/kg groups were examined, respectively. All animals of all groups in both sexes survived. In the 640 mg/kg groups of the both sexes, all animals were set to drowsiness from about 5 hours after administration, however, they recovered by the next morning. In the hematology examination, Hb, MCH, MCHC, WBC values were significantly decreased and MCV value was significant increased in the 640 mg/kg group of both sexes. In the serum biochemistry, items increased in the 640 mg/kg groups of both sexes returned to normal level after 14 days recovery period. Absolute and relative liver weight increase seen in the 160 mg/kg and above also returned to control level after recovery. Histopathologically, slight hepatocellular swelling was observed in the 160 mg/kg groups and severe hepatocellular swelling with vacuolization and slight necrosis was seen in the 640 mg/kg group. In conclusion, the no-observed-effect levels (NOEL) of S-421 under these conditions was judged to be 40 mg/kg/day.
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Affiliation(s)
- Yuko Matsushima
- Division of Cellular & Molecular Toxicology, National Institute of Health Sciences, Kamiyoga 1-18-1, Setagaya, Tokyo 158-8501, Japan.
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Belpoggi F, Soffritti M, Minardi F, Bua L, Cattin E, Maltoni C. Results of long-term carcinogenicity bioassays on tert-amyl-methyl-ether (TAME) and di-isopropyl-ether (DIPE) in rats. Ann N Y Acad Sci 2002; 982:70-86. [PMID: 12562629 DOI: 10.1111/j.1749-6632.2002.tb04925.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tert-amyl-methyl ether (TAME) was administered by gavage in extra virgin olive oil solution at concentrations of 750, 250, or 0 mg/kg bw to groups of 100 male and 100 female Sprague-Dawley rats 8 weeks old at the start of the experiment. Di-isopropyl ether (DIPE) was administered in the same manner at the doses of 1000, 250, or 0 mg/kg body weight to groups of 100 male and 100 female Sprague-Dawley rats. TAME and DIPE were each delivered in 1-mL solution 4 days a week for 78 weeks. Control animals received 1 mL of extra virgin olive oil without TAME or DIPE. At the end of the treatment period, all animals were kept under observation until spontaneous death. Under these test conditions, TAME and DIPE were found to be potential carcinogenic agents for various organs and tissues.
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Affiliation(s)
- Fiorella Belpoggi
- Cancer Research Center, European Ramazzini Foundation for Oncology and Environmental Sciences, Bologna, Italy
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Affiliation(s)
- Florian M Reichle
- Klinik für Anaesthesiologie, Klinikum Grosshadern, Universität München, Deutschland
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Altuntas TG, Kharasch ED. Glutathione S-conjugation of the sevoflurane degradation product, fluoromethyl-2,2-difluoro-1-(trifluoromethyl)vinyl ether (compound A) in human liver, kidney, and blood in vitro. Toxicol Appl Pharmacol 2001; 177:85-93. [PMID: 11740907 DOI: 10.1006/taap.2001.9302] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fluoromethyl-2,2-difluoro-1-(trifluoromethyl)vinyl ether (FDVE) is a fluorinated alkene formed by degradation of the volatile anesthetic sevoflurane in anesthesia machines. FDVE is nephrotoxic in rats and undergoes glutathione-dependent conjugation to form two alkane (G1, G2) and two alkene glutathione S-conjugates (G3, G4), cleavage to cysteine S-conjugates, and beta-lyase-catalyzed metabolism to reactive thionoacyl fluorides, which may react with cellular macromolecules to cause nephrotoxicity. Although similar metabolites have been identified in human urine in vivo, little is known about sites and mechanisms of GSH conjugation in humans. This investigation quantified FDVE-GSH conjugates formed by human hepatic and renal microsomal and cytosolic fractions and blood in vitro. LC-MS/MS analysis identified all four GSH conjugates (G1-G4) formed in all human subcellular fractions. Quantitative analysis indicated that the relative order of formation was G2 > G1 > G4 > G3 with human liver and kidney subfractions. In blood, the order was G1 > G4 > G2 > G3. These results demostrate that FDVE undergoes GSH-dependent conjugation in human liver and kidney microsomes and cytosol as well as blood, which may account for the detection of corresponding mercapturic acids in the urine of patients exposed to FDVE.
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Affiliation(s)
- T G Altuntas
- Department of Anesthesiology, University of Washington, Seattle, Washington 98195, USA
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Abstract
Compound A (2-fluoromethoxy-1,1,3,3,3-pentafluoro-1-propene) is a degradation product of the anesthetic sevoflurane which is created in closed-circuit anesthetic machines. Past in vivo and in vitro studies have implied that Compound A is nephrotoxic via bioactivation through the cysteine conjugate beta-lyase pathway. Although glutathione (GSH) conjugates of Compound A have been reported, it is not clear if they are formed enzymatically or via direct reaction with GSH. To determine if these metabolites are produced and toxic, a tissue slice system that first exposes male Fischer 344 rat liver slices to volatilized Compound A followed by exposure of rat kidney slices to the liver incubate was employed. Liver slices exposed to volatilized Compound A (6-12 microM medium conc.; approximately 23 ppm) exhibited a loss of K+ by 6 h, which was not seen in kidney slices exposed to Compound A. Aminobenzotriazole, a cytochrome P 450 suicide inhibitor, initially inhibits the cytotoxicity of Compound A to liver slices (at these times and concentrations). The sequential liver/kidney slice experiments using Compound A have not demonstrated nephrotoxic results. GSH conjugates were synthesized and was found to be nephrotoxic at concentrations above 91 microM (18 h), with higher concentrations showing toxicity at earlier times. Additionally, non-enzymatic reactions of Compound A with GSH or sulfhydryl-containing medium produces nephrotoxic products. These studies show that Compound A is directly toxic to the liver, possibly via P 450 activation, and Compound A can react with sulfhydryls directly to produce a nephrotoxic.
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Affiliation(s)
- J M Catania
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona, USA
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Zheng XH, Begay C, Lind RC, Gandolfi AJ. Humoral immune response to a sevoflurane degradation product in the guinea pig following inhalation exposure. Drug Chem Toxicol 2001; 24:339-46. [PMID: 11665647 DOI: 10.1081/dct-100106263] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Compound A (2-fluoromethoxy-1,1,3,3,3-pentafluoro-1-propene) is produced by reaction of the inhalation anesthetic, sevoflurane, with CO2 absorbents. Compound A has been reported to directly react with protein. Since adduction of proteins can transform them into antigenic material, Compound A was assessed for its ability to produce a humoral immune response. Male outbred Hartley guinea pigs (500-600 g, N = 7) were exposed via inhalation for 4 h to a subtoxic level (100 ppm) of Compound A, 3 times, at 42 day intervals. Blood samples obtained at 2, 14, 28 and 40 days after each exposure were measured for ALT, creatinine, and urea nitrogen and for the presence of antibodies to trifluoroacetylated guinea pig albumin (TFA-GSA). All indicators of liver and kidney injury remained within normal range throughout the course of the study. A humoral immune response to TFA-GSA was observed following each exposure to Compound A with a titer appearing by day 14 after exposure, peaking near day 28, and resolving to normal levels by day 40. The titer levels were approximately equivalent after each exposure and about one-third that previously seen in guinea pigs after multiple exposures to halothane. Compound A would appear to have the ability to form antigenic adducts during inhalation exposure. These findings are similar to those observed for halogenated inhalation anesthetics that have been linked to cases of immune-medicated idiosyncratic hepatitis and indicate that Compound A exposure may pose the same hazard.
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Affiliation(s)
- X H Zheng
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, Arizona, USA
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Geiss KT, Frazier JM. In vitro toxicities of experimental jet fuel system ice-inhibiting agents. Sci Total Environ 2001; 274:209-218. [PMID: 11453297 DOI: 10.1016/s0048-9697(01)00738-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
One research emphasis within the Department of Defense has been to seek the replacement of operational compounds with alternatives that pose less potential risk to human and ecological systems. Alternatives to glycol ethers, such as diethylene glycol monomethyl ether (M-DE), were investigated for use as jet fuel system ice-inhibiting agents (FSIIs). This group of chemicals includes three derivatives of 1,3-dioxolane-4-methanol (M-1, M-2, and M-3) and a 1,3-dioxane (M-27). In addition, M-DE was evaluated as a reference compound. Our approach was to implement an in vitro test battery based on primary rat hepatocyte cultures to perform initial toxicity evaluations. Hepatocytes were exposed to experimental chemicals (0, 0.001, 0.01, 0.1, 1, 10 mM dosages) for periods up to 24 h. Samples were assayed for lactate dehydrogenase (LDH) release, MTT dye reduction activity, glutathione level, and rate of protein synthesis as indicators of toxicity. Of the compounds tested, M-1, especially at the 10-mM dose, appeared to be more potent than the other chemicals, as measured by these toxicity assays. M-DE, the current FSII, elicited little response in the toxicity assays. Although some variations in toxicity were observed at the 10-mM dose, the in vitro toxicities of the chemicals tested (except for M-1) were not considerably greater than that of M-DE.
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Affiliation(s)
- K T Geiss
- Geo-Centers, Inc, Air Force Research Laboratory, Wright-Patterson AFB, OH 45433, USA
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Nishimura K, Okimoto H. Effects of organosilicon pyrethroid-like insecticides on nerve preparations of American cockroaches and crayfish. Pest Manag Sci 2001; 57:509-513. [PMID: 11407026 DOI: 10.1002/ps.317] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Quaternary organosilicon pyrethroid-like ethers (five compounds) and alkanes (three compounds) were used for neurophysiological tests. Their activities in inducing repetitive firing in the central nervous cord of the American cockroach (Periplaneta americana) were evaluated by an extracellular recording method. The ethers were more active than the corresponding alkanes. The ability of the compounds to cause conduction blockage was also measured using the same nerve preparations, but the effects were too weak to allow definitive activity values to be determined. The compounds prolonged the sodium tail-current in the crayfish giant axon under voltage clamp conditions. The rate of decay of the tail-current changed in parallel with the reported insecticidal activity against P americana. These findings indicated that tail-current activity was the most useful nerve parameter in predicting insecticidal activity. Regression analysis of the numerical data together with those reported for other alkanes revealed that the higher the tail-current activity, the higher the insecticidal activity when a structural feature and the hydrophobicity were considered separately. The insecticidal activity of the ethers was about seven-fold higher than that of the alkanes with equivalent tail-current activity and hydrophobicity. Variations in insecticidal activity were parabolically correlated with the hydrophobicity [(log P)opt = 9.1] when other factors were similar.
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Affiliation(s)
- K Nishimura
- Research Institute for Advanced Science and Technology, Osaka Prefecture University, 1-2 Gakuen-cho, Sakai, Osaka 599-8570, Japan.
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