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Chrysostomou PP, Freeman EL, Murphy MM, Pereira R, Esdaile DJ, Keohane P. A toxicological assessment of spermidine trihydrochloride produced using an engineered strain of Saccharomyces cerevisiae. Food Chem Toxicol 2024; 184:114428. [PMID: 38163454 DOI: 10.1016/j.fct.2023.114428] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
Spermidine is a polyamine consumed in the diet, endogenously biosynthesized in most cells, and produced by the intestinal microbiome. A variety of foods contribute to intake of spermidine along with other polyamines. Spermidine trihydrochloride (spermidine-3HCl) of high purity can be produced using an engineered strain of Saccharomyces cerevisiae. Spermidine has a demonstrated history of safe use in the diet; however, limited information is available in the public literature to assess the potential toxicity of spermidine-3HCl. To support a safety assessment for this spermidine-3HCl as a dietary source of spermidine, authoritative guideline and good laboratory practice (GLP) compliant in vitro genotoxicity assays (bacterial reverse mutation and mammalian micronucleus assays) and a 90-day oral (dietary) toxicity study in rats were conducted with spermidine-3HCl. Spermidine-3HCl was non-genotoxic in the in vitro assays, and no adverse effects were reported in the 90-day oral toxicity study up to the highest dose tested, 12500 ppm, equivalent to 728 mg/kg bw/day for males and 829 mg/kg bw/day for females. The subchronic no observed adverse effect level (NOAEL) is 728 mg/kg bw/day.
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Affiliation(s)
- Paola P Chrysostomou
- Exponent Inc., Center for Chemical Regulation and Food Safety, 1150 Connecticut Ave, NW, Suite 1100, Washington, DC, 20036, USA.
| | - Elaine L Freeman
- Exponent Inc., Center for Chemical Regulation and Food Safety, 1150 Connecticut Ave, NW, Suite 1100, Washington, DC, 20036, USA
| | - Mary M Murphy
- Exponent Inc., Center for Chemical Regulation and Food Safety, 1150 Connecticut Ave, NW, Suite 1100, Washington, DC, 20036, USA
| | - Rui Pereira
- Chrysea Labs Lda, Parque Tecnológico de Cantanhede Nucleo 4 Lote 2, 3060-197, Cantanhede, Portugal
| | - David J Esdaile
- Charles River Laboratories Hungary, Kft. H-8200 Veszprém, Szabadságpuszta, Hrsz. 028/1., Hungary
| | - Patrick Keohane
- Chrysea Labs Lda, Parque Tecnológico de Cantanhede Nucleo 4 Lote 2, 3060-197, Cantanhede, Portugal
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2
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Fehr M, Appl Á, Esdaile DJ, Naumann S, Schulz M, Dahms I. D-10-camphorsulfonic acid: Safety evaluation. Mutat Res Genet Toxicol Environ Mutagen 2020; 858-860:503257. [PMID: 33198938 DOI: 10.1016/j.mrgentox.2020.503257] [Citation(s) in RCA: 4] [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] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/11/2020] [Accepted: 09/12/2020] [Indexed: 11/19/2022]
Abstract
The safety of D-10-camphorsulfonic acid (CSA) was evaluated by genotoxicity testing and in a subchronic 90-day study in rats. Ames test and in vitro micronucleus test results, either in the absence or the presence of metabolic activation, were negative. Administration of CSA to Wistar rats in the drinking water (0.05, 0.20, or 1.00 mg/mL), for 90 days caused neither test-item-related mortality nor adverse clinical signs. The only macroscopic change seen at necropsy was enlarged testes in the high-dose animals. The 0.20 mg/mL (25 mg/kg bw/day) dose level was considered to be the no observed adverse effect level (NOAEL). A total intake calculation for consumers was performed, based on the intended maximal amount of 0.5 ppm CSA in feed, published transfer factors, and conservative tissue consumption data, resulting in 0.29 μg/kg bw/day. Therefore, the NOAEL is approximately 80,000 × the maximum estimated human exposure, a margin that is more than adequate to ensure consumer safety.
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Affiliation(s)
- Markus Fehr
- DSM Nutritional Products, Wurmisweg 576, 4303 Kaiseraugst, Switzerland.
| | - Ádám Appl
- Charles River, Veszprém, Szabadságpuszta, 8200, Hungary.
| | | | - Steffen Naumann
- ICCR-Roßdorf GmbH, In den Leppsteinswiesen 19, 64380 Roßdorf, Germany.
| | - Markus Schulz
- ICCR-Roßdorf GmbH, In den Leppsteinswiesen 19, 64380 Roßdorf, Germany.
| | - Irina Dahms
- DSM Nutritional Products, Wurmisweg 576, 4303 Kaiseraugst, Switzerland.
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3
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Botham PA, Chamberlain M, Barratt MD, Curren RD, Esdaile DJ, Gardner JR, Gordon VC, Hildebrand B, Lewis RW, Liebsch M, Logemann P, Osborne R, Ponec M, Régnier JF, Steiling W, Walker AP, Balls M. A Prevalidation Study on In Vitro Skin Corrosivity Testing. Altern Lab Anim 2020. [DOI: 10.1177/026119299502300207] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Philip A. Botham
- ZENECA Central Toxicology Laboratory, Alderley Park, Macclesfield, Cheshire SK10 4TJ, UK
| | - Mark Chamberlain
- Environmental Safety Laboratory, Unilever Research, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - Martin D. Barratt
- Environmental Safety Laboratory, Unilever Research, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - Rodger D. Curren
- Microbiological Associates Inc., 9900 Blackwell Road, Rockville, MD 20878, USA
| | - David J. Esdaile
- Rhône-Poulenc Secteur Agro, 355 Rue Dostoievski, BP 153, 06903 Sophia Antipolis Cedex, France
| | - John R. Gardner
- Hazleton Europe, Otley Road, Harrogate, N. Yorkshire HG3 1PY, UK
| | | | | | - Richard W. Lewis
- ZENECA Central Toxicology Laboratory, Alderley Park, Macclesfield, Cheshire SK10 4TJ, UK
| | - Manfred Liebsch
- ZEBET, Bundesinstitut für gesundheitlichen Verbraucherschutz und Veterinärmedizin (BgVV), Diedersdorfer Weg 1, D-12277 Berlin, Germany
| | - Pamela Logemann
- Tissue Sciences, 10933 North Torrey Pines Road, La Jolla, CA 92037-1005, USA
| | - Rosemarie Osborne
- The Procter & Gamble Company, Miami Valley Laboratories, P.O. Box 538707, Cincinnati, OH 45253-8707, USA
| | - Maria Ponec
- Department of Dermatology, University Hospital Leiden, P.O. Box 9600, 2300 RC Leiden, The Netherlands
| | | | | | - Arthur P. Walker
- Apojay Consultancy, 6 Cragside, Whitley Bay, Tyne & Wear NE26 3DU, UK
| | - Michael Balls
- ECVAM, JRC Environment Institute, 21020 Ispra (Va), Italy
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Worth AP, Fentem JH, Balls M, Botham PA, Curren RD, Earl LK, Esdaile DJ, Liebsch M. An Evaluation of the Proposed OECD Testing Strategy for Skin Corrosion. Altern Lab Anim 2020. [DOI: 10.1177/026119299802600512] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The use of testing strategies which incorporate a range of alternative methods and which use animals only as a last resort is widely considered to provide a reliable way of predicting chemical toxicity while minimising animal testing. The widespread concern over the severity of the Draize rabbit test for assessing skin irritation and corrosion led to the proposal of a stepwise testing strategy at an OECD workshop in January 1996. Subsequently, the proposed testing strategy was adopted, with minor modifications, by the OECD Advisory Group on Harmonization of Classification and Labelling. This article reports an evaluation of the proposed OECD testing strategy as it relates to the classification of skin corrosives. By using a set of 60 chemicals, an assessment was made of the effect of applying three steps in the strategy, taken both individually and in sequence. The results indicate that chemicals can be classified as corrosive (C) or non-corrosive (NC) with sufficient reliability by the sequential application of three alternative methods, i.e., structure-activity relationships (where available), pH measurements, and a single in vitro method (either the rat skin transcutaneous electrical resistance (TER) assay or the EPISKIN™ assay). It is concluded that the proposed OECD strategy for skin corrosion can be simplified without compromising its predictivity. For example, it does not appear necessary to measure acid/alkali reserve (buffering capacity) in addition to pH for the classification of pure chemicals.
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Affiliation(s)
| | | | - Michael Balls
- ECVAM, JRC Environment Institute, 21020 Ispra (VA), Italy
| | - Philip A. Botham
- Central Toxicology Laboratory, ZENECA, Alderley Park, Macclesfield, Cheshire SK10 4TJ, UK
| | - Rodger D. Curren
- Institute for In Vitro Sciences, 21 Firstfield Road, Gaithersburg, MD 20878, USA
| | - Lesley K. Earl
- SEAC Toxicology Unit, Unilever Research, Colworth House, Sharnbrook, Bedfordshire MK44 1LQ, UK
| | - David J. Esdaile
- Rhône-Poulenc Agro, 355 rue Dostoievski, 06903 Sophia Antipolis Cedex, France
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Katz I, Voronetska K, Libardi M, Chalopin M, Privat P, J Esdaile D, Mougin G, Farjot G, Milet A. Computational fluid dynamics applied to the ventilation of small-animal laboratory cages. Lab Anim 2020; 55:150-157. [PMID: 32722999 DOI: 10.1177/0023677220937718] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Several studies based on in vivo or in vitro models have found promising results for the noble gas argon in neuroprotection against ischaemic pathologies. The development of argon as a medicinal product includes the requirement for toxicity testing through non-clinical studies. The long exposure period of animals (rats) during several days results in technical and logistic challenges related to the gas administration. In particular, a minimum of 10 air changes per hour (ACH) to maintain animal welfare results in extremely large volumes of experimental gas required if the gas is not recirculated. The difficulty with handling the many cylinders prompted the development of such a recirculation-based design. To distribute the recirculating gas to individually ventilated cages and monitor them properly was deemed more difficult than constructing a single large enclosure that will hold several open cages. To address these concerns, a computational fluid dynamics (CFD) analysis of the preliminary design was performed. A purpose-made exposure chamber was designed based on the CFD simulations. Comparisons of the simulation results to measurements of gas concentration at two cage positions while filling show that the CFD results compare well to these limited experiments. Thus, we believe that the CFD results are representative of the gas distribution throughout the enclosure. The CFD shows that the design provides better gas distribution (i.e. a higher effective air change rate) than predicted by 10 ACH.
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Affiliation(s)
- Ira Katz
- Medical R&D, Healthcare World Business Line, Air Liquide Santé International, Innovation Campus Paris, France
| | - Kateryna Voronetska
- Computational and Data Science, R&D, Air Liquide, Innovation Campus Paris, France
| | - Mickaël Libardi
- Analysis and Fine Chemistry Group, R&D, Air Liquide, Innovation Campus Paris, France
| | - Matthieu Chalopin
- Medical R&D, Healthcare World Business Line, Air Liquide Santé International, Innovation Campus Paris, France
| | - Patricia Privat
- Analysis and Fine Chemistry Group, R&D, Air Liquide, Innovation Campus Paris, France
| | | | - Guillaume Mougin
- Computational and Data Science, R&D, Air Liquide, Innovation Campus Paris, France
| | - Géraldine Farjot
- Medical R&D, Healthcare World Business Line, Air Liquide Santé International, Innovation Campus Paris, France
| | - Aude Milet
- Medical R&D, Healthcare World Business Line, Air Liquide Santé International, Innovation Campus Paris, France
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Reno FE, Edwards CN, Bendix Jensen M, Török-Bathó M, Esdaile DJ, Piché C, Triest M, Carballo D. Needle-free nasal delivery of glucagon for treatment of diabetes-related severe hypoglycemia: toxicology of polypropylene resin used in delivery device. Cutan Ocul Toxicol 2015; 35:242-7. [DOI: 10.3109/15569527.2015.1089884] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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7
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Esdaile DJ, Sipos K, Gaty S. Reproductive toxicology studies in Japanese Quail: reference data. Toxicol Lett 2014. [DOI: 10.1016/j.toxlet.2014.06.907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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8
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François IEJA, Lescroart O, Veraverbeke WS, Kubaszky R, Hargitai J, Esdaile DJ, Beres E, Soni MG, Cockburn A, Broekaert WF. Safety Assessment of a Wheat Bran Extract Containing Arabinoxylan-Oligosaccharides: Mutagenicity, Clastogenicity, and 90-Day Rat-Feeding Studies. Int J Toxicol 2010; 29:479-95. [DOI: 10.1177/1091581810374219] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Wheat bran extract (WBE) is a food-grade preparation that is highly enriched in arabinoxylan-oligosaccharides. As part of the safety evaluation of WBE, its genotoxic potential was assessed in a bacterial reverse mutagenicity assay (Ames test) and a chromosome aberration assay on Chinese hamster lung fibroblast cells. These in vitro genotoxicity assays showed no evidence of mutagenic or clastogenic activity with WBE. The safety of WBE was furthermore evaluated in a subchronic toxicity study on rats that were fed a semisynthetic diet (AIN 93G) containing 0.3%, 1.5%, or 7.5% WBE for 13 weeks, corresponding to an average intake of 0.2, 0.9, and 4.4 g/kg body weight (bw) per day, with control groups receiving the unsupplemented AIN 93G, AIN 93G with 7.5% inulin, or AIN 93G with 7.5% wheat bran. Based on this rat-feeding study, the no-observed-adverse-effect level (NOAEL) for WBE was determined as 4.4 g/kg (bw)/d, the highest dose tested.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Andrew Cockburn
- Toxico-Logical Consulting Ltd, Gravesend Farm, Albury Ware, Hertfordshire, SG 11 2LW, UK
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9
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Hérouet C, Esdaile DJ, Mallyon BA, Debruyne E, Schulz A, Currier T, Hendrickx K, van der Klis RJ, Rouan D. Safety evaluation of the phosphinothricin acetyltransferase proteins encoded by the pat and bar sequences that confer tolerance to glufosinate-ammonium herbicide in transgenic plants. Regul Toxicol Pharmacol 2005; 41:134-49. [PMID: 15698537 DOI: 10.1016/j.yrtph.2004.11.002] [Citation(s) in RCA: 147] [Impact Index Per Article: 7.7] [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: 06/21/2004] [Revised: 10/31/2004] [Accepted: 11/08/2004] [Indexed: 11/20/2022]
Abstract
Transgenic plant varieties, which are tolerant to glufosinate-ammonium, were developed. The herbicide tolerance is based upon the presence of either the bar or the pat gene, which encode for two homologous phosphinothricin acetyltransferases (PAT), in the plant genome. Based on both a review of published literature and experimental studies, the safety assessment reviews the first step of a two-step-approach for the evaluation of the safety of the proteins expressed in plants. It can be used to support the safety of food or feed products derived from any crop that contains and expresses these PAT proteins. The safety evaluation supports the conclusion that the genes and the donor microorganisms (Streptomyces) are innocuous. The PAT enzymes are highly specific and do not possess the characteristics associated with food toxins or allergens, i.e., they have no sequence homology with any known allergens or toxins, they have no N-glycosylation sites, they are rapidly degraded in gastric and intestinal fluids, and they are devoid of adverse effects in mice after intravenous administration at a high dose level. In conclusion, there is a reasonable certainty of no harm resulting from the inclusion of the PAT proteins in human food or in animal feed.
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10
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Thomas K, Aalbers M, Bannon GA, Bartels M, Dearman RJ, Esdaile DJ, Fu TJ, Glatt CM, Hadfield N, Hatzos C, Hefle SL, Heylings JR, Goodman RE, Henry B, Herouet C, Holsapple M, Ladics GS, Landry TD, MacIntosh SC, Rice EA, Privalle LS, Steiner HY, Teshima R, Van Ree R, Woolhiser M, Zawodny J. A multi-laboratory evaluation of a common in vitro pepsin digestion assay protocol used in assessing the safety of novel proteins. Regul Toxicol Pharmacol 2004; 39:87-98. [PMID: 15041142 DOI: 10.1016/j.yrtph.2003.11.003] [Citation(s) in RCA: 200] [Impact Index Per Article: 10.0] [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: 09/30/2003] [Indexed: 11/25/2022]
Abstract
Rationale. Evaluation of the potential allergenicity of proteins derived from genetically modified foods has involved a weight of evidence approach that incorporates an evaluation of protein digestibility in pepsin. Currently, there is no standardized protocol to assess the digestibility of proteins using simulated gastric fluid. Potential variations in assay parameters include: pH, pepsin purity, pepsin to target protein ratio, target protein purity, and method of detection. The objective was to assess the digestibility of a common set of proteins in nine independent laboratories to determine the reproducibility of the assay when performed using a common protocol. Methods. A single lot of each test protein and pepsin was obtained and distributed to each laboratory. The test proteins consisted of Ara h 2 (a peanut conglutin-like protein), beta-lactoglobulin, bovine serum albumin, concanavalin A, horseradish peroxidase, ovalbumin, ovomucoid, phosphinothricin acetyltransferase, ribulose diphosphate carboxylase, and soybean trypsin inhibitor. A ratio of 10U of pepsin activity/microg test protein was selected for all tests (3:1 pepsin to protein, w:w). Digestions were performed at pH 1.2 and 2.0, with sampling at 0.5, 2, 5, 10, 20, 30, and 60min. Protein digestibility was assessed from stained gels following SDS-PAGE of digestion samples and controls. Results. Results were relatively consistent across laboratories for the full-length proteins. The identification of proteolytic fragments was less consistent, being affected by different fixation and staining methods. Overall, assay pH did not influence the time to disappearance of the full-length protein or protein fragments, however, results across laboratories were more consistent at pH 1.2 (91% agreement) than pH 2.0 (77%). Conclusions. These data demonstrate that this common protocol for evaluating the in vitro digestibility of proteins is reproducible and yields consistent results when performed using the same proteins at different laboratories.
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Affiliation(s)
- K Thomas
- ILSI Health and Environmental Sciences Institute, Washington, DC, USA.
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11
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Heylings JR, Diot S, Esdaile DJ, Fasano WJ, Manning LA, Owen HM. A prevalidation study on the in vitro skin irritation function test (SIFT) for prediction of acute skin irritation in vivo: results and evaluation of ECVAM Phase III. Toxicol In Vitro 2003; 17:123-38. [PMID: 12650665 DOI: 10.1016/s0887-2333(02)00130-3] [Citation(s) in RCA: 35] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A prevalidation study sponsored by the European Centre for the Validation of Alternative Methods (ECVAM) on in vitro tests for acute skin irritation is aimed at identifying non-animal tests capable of discriminating irritants (I) from non-irritants (NI), as defined according to European Union and OECD. This paper reports on Phase III for one of the methods, the skin integrity function test (SIFT), assessing the protocol performance of the SIFT, in terms of reproducibility and predictive ability, in three laboratories. The barrier function properties of excised mouse skin were determined using a set of 20 coded chemicals (10 I, 10 NI), using the endpoints of trans-epidermal water loss (TEWL) and electrical resistance (ER). The basis of the SIFT prediction model is if the ratios of the pre- and post-application values for either TEWL or ER are greater than five-fold, then the test chemical is deemed irritant (I). If the ratio of both parameters is less than five-fold then the chemical is deemed non-irritant (NI). Analysis of variance (ANOVA) indicated that the intra-lab reproducibility was acceptable but that the inter-lab reproducibility was not. Overall, the SIFT test under-predicted the irritancy of the test chemicals chosen for Phase III with an overall accuracy of only 55%. The sensitivity value (ability to correctly predict I) was only 30%. The specificity (ability to predict NI) of the test was better at 80%. A retrospective examination of the SIFT results was undertaken using Student's t-test and a significance level of P<0.05 to predict an irritant based on changes in the TEWL ratio values. This improved the predictivity of the SIFT test, giving a specificity of 60%, a sensitivity of 80% and an overall accuracy of 70%. Appropriate modifications to the prediction model have now been made and the SIFT will be re-examined in a new validation exercise to investigate the potential of this non-animal method to predict acute skin irritation potential.
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Affiliation(s)
- J R Heylings
- Syngenta Central Toxicology Laboratory, Alderley Park, Macclesfield, Cheshire SK10 4TJ, UK.
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12
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Rockett JC, Swales KE, Esdaile DJ, Gibson GG. Use of suppression-PCR subtractive hybridisation to identify genes that demonstrate altered expression in male rat and guinea pig livers following exposure to Wy-14,643, a peroxisome proliferator and non-genotoxic hepatocarcinogen. Toxicology 2000; 144:13-29. [PMID: 10781867 DOI: 10.1016/s0300-483x(99)00214-0] [Citation(s) in RCA: 6] [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: 11/26/2022]
Abstract
Understanding the genetic profile of a cell at all stages of normal and carcinogenic development should provide an essential aid to developing new strategies for the prevention, early detection, diagnosis and treatment of cancers. We have attempted to identify some of the genes that may be involved in peroxisome-proliferator (PP)-induced non-genotoxic hepatocarcinogenesis using suppression PCR subtractive hybridisation (SSH). Wistar rats (male) were chosen as a representative susceptible species and Duncan-Hartley guinea pigs (male) as a resistant species to the hepatocarcinogenic effects of the PP, [4-chloro-6-(2,3-xylidino)-2-pyrimidinylthio] acetic acid (Wy-14,643). In each case, groups of four test animals were administered a single dose of Wy-14,643 (250 mg/kg per day in corn oil) by gastric intubation for 3 consecutive days. The control animals received corn oil only. On the fourth day the animals were killed and liver mRNA extracted. SSH was carried out using mRNA extracted from the rat and guinea pig livers, and used to isolate genes that were up and downregulated following Wy-14,643 treatment. These genes included some predictable (and hence positive control) species such as CYP4A1 and CYP2C11 (upregulated and downregulated in rat liver, respectively). Several genes that may be implicated in hepatocarcinogenesis have also been identified, as have some unidentified species. This work thus provides a starting point for developing a molecular profile of the early effects of a non-genotoxic carcinogen in sensitive and resistant species that could ultimately lead to a short-term assay for this type of toxicity.
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Affiliation(s)
- J C Rockett
- Molecular Toxicology Group, School of Biological Sciences, University of Surrey, Guildford, UK
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13
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Abstract
1. An important feature of the work of many molecular biologists is identifying which genes are switched on and off in a cell under different environmental conditions or subsequent to xenobiotic challenge. Such information has many uses, including the deciphering of molecular pathways and facilitating the development of new experimental and diagnostic procedures. However, the student of gene hunting should be forgiven for perhaps becoming confused by the mountain of information available as there appears to be almost as many methods of discovering differentially expressed genes as there are research groups using the technique. 2. The aim of this review was to clarify the main methods of differential gene expression analysis and the mechanistic principles underlying them. Also included is a discussion on some of the practical aspects of using this technique. Emphasis is placed on the so-called 'open' systems, which require no prior knowledge of the genes contained within the study model. Whilst these will eventually be replaced by 'closed' systems in the study of human, mouse and other commonly studied laboratory animals, they will remain a powerful tool for those examining less fashionable models. 3. The use of suppression-PCR subtractive hybridization is exemplified in the identification of up- and down-regulated genes in rat liver following exposure to phenobarbital, a well-known inducer of the drug metabolizing enzymes. 4. Differential gene display provides a coherent platform for building libraries and microchip arrays of 'gene fingerprints' characteristic of known enzyme inducers and xenobiotic toxicants, which may be interrogated subsequently for the identification and characterization of xenobiotics of unknown biological properties.
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Affiliation(s)
- J C Rockett
- Molecular Toxicology Laboratory, School of Biological Sciences, University of Surrey, Guildford, UK
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14
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Balls M, Berg N, Bruner LH, Curren RD, de Silva O, Earl LK, Esdaile DJ, Fentem JH, Liebsch M, Ohno Y, Prinsen MK, Spielmann H, Worth AP. Eye Irritation Testing: The Way Forward. The Report and Recommendations of ECVAM Workshop 34. Altern Lab Anim 1999; 27:53-77. [PMID: 25423402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This is the report of the thirty-fourth of a series of workshops organised by the European Centre for the Validation of Alternative Methods (ECVAM). ECVAM's main goal, as defined in 1993 by its Scientific Advisory Committee, is to promote the scientific and regulatory acceptance of alternative methods which are of importance to the biosciences and which reduce, refine or replace the use of laboratory animals. One of the first priorities set by ECVAM was the implementation of procedures which would enable it to become well-informed about the state-of-the-art of non-animal test development and validation, and the potential for the possible incorporation of alternative tests into regulatory procedures. It was decided that this would be best achieved by the organisation of ECVAM workshops on specific topics, at which small groups of invited experts would review the current status of various types of in vitro tests and their potential uses, and make recommendations about the best ways forward (1). The workshop on Eye Irritation Testing: The Way Forward was held in Egham, UK, on 15-17 June 1998, under the chairmanship of Michael Balls (ECVAM, Italy). The workshop had two aims, the first of which was to review some of the previous multi-laboratory validation studies on alternatives to the Draize eye test and assess why many promising alternative methods were not successful in these studies. The second aim was to discuss strategies for making progress toward the short-term reduction, refinement, and eventual replacement, of the Draize test, including: a new approach to the validation of in vitro tests for eye irritancy, based on the use of reference standards, which promises to overcome some of the problems encountered in previous studies; the use of stepwise testing strategies which reduce and refine the use of animals in eye irritation testing; the use of multivariate and other statistical techniques for the further analysis of data generated in previous validation studies; and a programme of research aimed at understanding the underlying mechanisms of eye irritation.
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Affiliation(s)
- M Balls
- ECVAM, JRC Environment Institute, 21020 Ispra, Italy
| | - N Berg
- Novo Nordisk, Novo Alle, 2880 Bagsvaerd, Denmark
| | - L H Bruner
- Procter & Gamble (Health and Beauty Care), Lovett House, Lovett Road, Staines, Middlesex TW18 3AZ, UK
| | - R D Curren
- Institute for In Vitro Sciences, 21 Firstfield Road, Gaithersburg, MD 20878, USA
| | - O de Silva
- L'Oréal Recherche Avancée - Sciences du Vivant, 1 Avenue Eugène Schueller, 93601 Aulnay-sous-Bois Cedex, France
| | - L K Earl
- SEAC Toxicology Unit, Unilever Research, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - D J Esdaile
- Rhône-Poulenc, 355 rue Dostoievski, 06903 Sophia Antipolis Cedex, France
| | - J H Fentem
- ECVAM, JRC Environment Institute, 21020 Ispra, Italy
| | - M Liebsch
- ZEBET, BgVV, Diedersdorfer Weg 1, 12277 Berlin, Germany
| | - Y Ohno
- Division of Pharmacology, Biological Safety Research Centre, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setakaya-ku, Tokyo 158, Japan
| | - M K Prinsen
- TNO Nutrition and Food Research Institute, Division of Toxicology, 3700 AJ Zeist, The Netherlands
| | - H Spielmann
- ZEBET, BgVV, Diedersdorfer Weg 1, 12277 Berlin, Germany
| | - A P Worth
- ECVAM, JRC Environment Institute, 21020 Ispra, Italy
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15
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Esdaile DJ. Perspectives on the past, present and future of computer prediction in toxicology. Toxicol Lett 1998; 102-103:609-10. [PMID: 10022321 DOI: 10.1016/s0378-4274(98)00256-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- D J Esdaile
- Rhône-Poulenc Agro, Sophia Antipolis, France.
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16
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Worth AP, Fentem JH, Balls M, Botham PA, Curren RD, Earl LK, Esdaile DJ. An evaluation of the proposed OECD testing strategy for skin corrosion. Altern Lab Anim 1998; 26:709-720. [PMID: 26042494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The use of testing strategies which incorporate a range of alternative methods and which use animals only as a last resort is widely considered to provide a reliable way of predicting chemical toxicity while minimising animal testing. The widespread concern over the severity of the Draize rabbit test for assessing skin irritation and corrosion led to the proposal of a stepwise testing strategy at an OECD workshop in January 1996. Subsequently, the proposed testing strategy was adopted, with minor modifications, by the OECD Advisory Group on Harmonization of Classification and Labelling. This article reports an evaluation of the proposed OECD testing strategy as it relates to the classification of skin corrosives. By using a set of 60 chemicals, an assessment was made of the effect of applying three steps in the strategy, taken both individually and in sequence. The results indicate that chemicals can be classified as corrosive (C) or non-corrosive (NC) with sufficient reliability by the sequential application of three alternative methods, i.e., structure-activity relationships (where available), pH measurements, and a single in vitro method (either the rat skin transcutaneous electrical resistance (TER) assay or the EPISKIN™ assay). It is concluded that the proposed OECD strategy for skin corrosion can be simplified without compromising its predictivity. For example, it does not appear necessary to measure acid/alkali reserve (buffering capacity) in addition to pH for the classification of pure chemicals.
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Affiliation(s)
- A P Worth
- ECVAM, JRC Environment Institute, Ispra, Italy
| | - J H Fentem
- ECVAM, JRC Environment Institute, Ispra, Italy
| | - M Balls
- ECVAM, JRC Environment Institute, Ispra, Italy
| | - P A Botham
- Central Toxicology Laboratory, ZENECA, Alderley Park, Macclesfield, UK
| | - R D Curren
- Institute for In Vitro Sciences, Gaithersburg, MD, USA
| | - L K Earl
- SEAC Toxicology Unit, Unilever Research, Sharnbrook, UK
| | - D J Esdaile
- Rhône-Poulenc Agro, Sophia Antipolis Cedex, France
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17
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Rockett JC, Esdaile DJ, Gibson GG. Molecular profiling of non-genotoxic hepatocarcinogenesis using differential display reverse transcription-polymerase chain reaction (ddRT-PCR). Eur J Drug Metab Pharmacokinet 1997; 22:329-33. [PMID: 9512930 DOI: 10.1007/bf03190966] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 02/06/2023]
Abstract
The technique of differential display reverse transcription-polymerase chain reaction (ddRT-PCR) has been used to produce unique profiles of up-regulated and down-regulated gene expression in the liver of male Wistar rats following short term exposure to the non-genotoxic hepatocarcinogens, phenobarbital and WY-14,643. Animals were treated for 3 days, whereupon their livers were extracted and snap frozen. mRNA was prepared from the livers and used for ddRT-PCR. Individual bands from the differential displays were extracted and cloned. False positives were eliminated by dotblot screening and true positives then sequenced and identified.
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Affiliation(s)
- J C Rockett
- Molecular Toxicology Group, School of Biological Sciences, University of Surrey, Guildford, UK
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18
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Affiliation(s)
- D J Esdaile
- Rhone-Poulenc-Secteur Agro, Sophia Antipolis, France
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19
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Fielder RJ, Allen JA, Boobis AR, Botham PA, Doe J, Esdaile DJ, Gatehouse DG, Hodson-Walker G, Morton DB, Kirkland DJ. Report of British Toxicology Society/UK Environmental Mutagen Society Working Group. Dose setting in in vivo mutagenicity assays. Mutagenesis 1992; 7:313-9. [PMID: 1470025 DOI: 10.1093/mutage/7.5.313] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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20
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Baldwin MK, Berry PH, Esdaile DJ, Linnett SL, Martin JG, Peristianis GC, Priston RA, Simpson BJ, Smith JD. Feeding studies in rats with mineral hydrocarbon food grade white oils. Toxicol Pathol 1992; 20:426-35. [PMID: 1295071 DOI: 10.1177/019262339202000312] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [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: 12/26/2022]
Abstract
This investigation compared the effects of feeding rats diets containing food grade white oil processed by either conventional oleum treatment or the more modern method of catalytic hydrogenation. In two separate experiments, male or female Fischer-344 rats were given free access for 90 days to diets containing 0, 10, 100, 500, 5,000, 10,000, or 20,000 ppm of either oleum-treated white oil (OTWO) or hydrotreated white oil (HTWO). There were no mortalities and no adverse clinical signs associated with feeding either white oil. Treatment-related effects evidenced by hematological, clinical chemical, and pathological changes were generally dose-related and more marked in female than in male rats, and the OTWO caused a greater pathological response than the HTWO. Tissue residues of saturated hydrocarbons were up to 5.2 times higher in female rats than in males. Rats fed 5,000 ppm or more of either white oil showed dose-related alterations in several hematological and clinical chemistry variates associated mainly with hepatic damage or functional alteration. At necropsy, mesenteric lymph nodes were enlarged, and increases in weight of liver, kidney, and spleen were significant. Microscopic changes were characterized by multifocal lipogranulomata in mesenteric lymph node and liver. No changes were observed in rats fed OTWO or HTWO for 90 days at dietary concentrations of 10 or 100 ppm, equivalent to a minimum intake of 0.65 and 6.4 mg/kg/day, respectively. Differences in degree of pathological response associated with each oil may have been due to their differences in specification rather than processing method.
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Affiliation(s)
- M K Baldwin
- Shell Research Ltd., Sittingbourne Research Centre, Kent, United Kingdom
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