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More SJ, Bampidis V, Benford D, Bragard C, Halldorsson TI, Hernández‐Jerez AF, Bennekou SH, Koutsoumanis K, Lambré C, Machera K, Mullins E, Nielsen SS, Schlatter JR, Schrenk D, Turck D, Younes M, Boon P, Ferns GAA, Lindtner O, Smolders E, Wilks M, Bastaki M, de Sesmaisons‐Lecarré A, Ferreira L, Greco L, Kass GEN, Riolo F, Leblanc J. Re-evaluation of the existing health-based guidance values for copper and exposure assessment from all sources. EFSA J 2023; 21:e07728. [PMID: 36694841 PMCID: PMC9843535 DOI: 10.2903/j.efsa.2023.7728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Copper is an essential micronutrient and also a regulated product used in organic and in conventional farming pest management. Both deficiency and excessive exposure to copper can have adverse health effects. In this Scientific Opinion, the EFSA 2021 harmonised approach for establishing health-based guidance values (HBGVs) for substances that are regulated products and also nutrients was used to resolve the divergent existing HBGVs for copper. The tightly regulated homeostasis prevents toxicity manifestation in the short term, but the development of chronic copper toxicity is dependent on copper homeostasis and its tissue retention. Evidence from Wilson disease suggests that hepatic retention is indicative of potential future and possibly sudden onset of copper toxicity under conditions of continuous intake. Hence, emphasis was placed on copper retention as an early marker of potential adverse effects. The relationships between (a) chronic copper exposure and its retention in the body, particularly the liver, and (b) hepatic copper concentrations and evidence of toxicity were examined. The Scientific Committee (SC) concludes that no retention of copper is expected to occur with intake of 5 mg/day and established an Acceptable Daily Intake (ADI) of 0.07 mg/kg bw. A refined dietary exposure assessment was performed, assessing contribution from dietary and non-dietary sources. Background copper levels are a significant source of copper. The contribution of copper from its use as plant protection product (PPP), food and feed additives or fertilisers is negligible. The use of copper in fertilisers or PPPs contributes to copper accumulation in soil. Infant formula and follow-on formula are important contributors to dietary exposure of copper in infants and toddlers. Contribution from non-oral sources is negligible. Dietary exposure to total copper does not exceed the HBGV in adolescents, adults, elderly and the very elderly. Neither hepatic copper retention nor adverse effects are expected to occur from the estimated copper exposure in children due to higher nutrient requirements related to growth.
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Mandil R, Prakash A, Rahal A, Singh SP, Sharma D, Kumar R, Garg SK. In vitro and in vivo effects of flubendiamide and copper on cyto-genotoxicity, oxidative stress and spleen histology of rats and its modulation by resveratrol, catechin, curcumin and α-tocopherol. BMC Pharmacol Toxicol 2020; 21:29. [PMID: 32326976 PMCID: PMC7179012 DOI: 10.1186/s40360-020-00405-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 03/20/2020] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Living organisms are frequently exposed to more than one xenobiotic at a time either by ingestion of contaminated food/fodder or due to house-hold practices, occupational hazards or through environment. These xenobiotics interact individually or in combination with biological systems and act as carcinogen or produce other toxic effects including reproductive and degenerative diseases. Present study was aimed to investigate the cyto-genotoxic effects of flubendiamide and copper and ameliorative potential of certain natural phyotconstituent antioxidants. METHOD In vitro cytogenotoxic effects were evaluated by employing battery of assays including Propidium iodide staining, Tunel assay, Micronuclei, DNA fragmentation and Comet assay on isolated splenocytes and their prevention by resveratrol (5 and 10 μM), catechin (10 and 20 μM), curcumin (5 and 10 μM) and α-tocopherol (5, 10 and 20 μM). In vivo study was also undertaken daily oral administration of flubendiamide (200 mg/kg) or copper (33 mg/kg) and both these in combination, and also all these concurrently with of α-tocopherol to Wistar rats for 90 days. RESULTS Flubendiamide and copper produced concentration-dependent cytotoxic effects on splenocytes and at median lethal concentrations, flubendiamide (40 μM) and copper (40 μM) respectively produced 71 and 81% nonviable cells, higher number of Tunel+ve apoptotic cells, 7.86 and 9.16% micronucleus and 22.90 and 29.59 comets/100 cells and DNA fragmentation. In vivo study revealed significant (P < 0.05) increase in level of lipid peroxidation (LPO) and decrease in glutathione peroxidase (GPx), glutathione-S-transferase (GST) and superoxide dismutase (SOD) activities in groups exposed to flubendiamide or copper alone or both these in combination. Histopathological examination of rat spleens revealed depletion of lymphoid tissue, separation of splenocytes and rarification in splenic parenchyma of xenobiotic(s) treated groups. CONCLUSION Flubendiamide and copper induce oxidative stress and produce cytogenotoxic effects along with histoarchitectural changes in spleen. All four tested natural antioxidants (resveratrol, catechin, curcumin and α-tocopherol) reduced flubendiamide and copper-induced cytotoxic effects in rat splenocytes. Rat splenocytes are very sensitive to flubendiamide and copper-induced cytogenotoxicity, therefore, these can be effectively employed for screening of compounds for their cytogenotoxic potential. α-tocopherol was effective in restoring alterations in oxidative stress biomarkers and preventing histoarchitectural lesions in spleen.
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Affiliation(s)
- Rajesh Mandil
- Department of Veterinary Pharmacology and Toxicology, College of Veterinary and Animal Sciences, Sardar Vallabhbhai Patel University of Agriculture and Tecahnology, 250110, Meerut, India
| | - Atul Prakash
- Department of Veterinary Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, U.P. Pt. Deen Dayal Upadhyay Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go- Anusandhan Sansthan (DUVASU), -281001, Mathura, India
| | - Anu Rahal
- Division of Goat Health, Central Institute for Research on Goat (CIRG), Makhdoom, Farah, Mathura, Uttar Pradesh 281122 India
| | - S. P. Singh
- Department of Animal Genetics & Breeding, College of Veterinary Science and Animal Husbandry, U.P. Pt. Deen Dayal Upadhyay Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go-Anusandhan Sansthan (DUVASU), 281001, Mathura, India
| | - Deepak Sharma
- Department of Animal Genetics & Breeding, College of Veterinary Science and Animal Husbandry, U.P. Pt. Deen Dayal Upadhyay Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go-Anusandhan Sansthan (DUVASU), 281001, Mathura, India
| | - Rahul Kumar
- Department of Veterinary Pathology, College of Veterinary Science and Animal Husbandry, U.P. Pt. Deen Dayal Upadhyay Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go-Anusandhan Sansthan (DUVASU), 281001, Mathura, India
| | - Satish Kumar Garg
- Department of Veterinary Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, U.P. Pt. Deen Dayal Upadhyay Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go- Anusandhan Sansthan (DUVASU), -281001, Mathura, India
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Çelik B, Özparlak H. Determination of genotoxic and antigenotoxic effects of wild-grown Reishi mushroom ( Ganoderma lucidum) using the hen's egg test for analysis of micronucleus induction. Biotech Histochem 2019; 94:628-636. [PMID: 31282205 DOI: 10.1080/10520295.2019.1622784] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The micronucleus (MN) technique is commonly used for genotoxicity testing. The hen's egg test (HET) for analysis of MN induction (HET-MN) is an inexpensive, rapid and simple genotoxicity assay that is compatible with animal protection and ethical considerations. Ganoderma lucidum (Curtis) P. Karst is known also as reishi mushroom and mushroom of immortality. It has long been used to treat disorders including fungal infections, influenza, common cold, hepatitis, diabetes, high cholesterol and cancer in many countries including China and Japan. G. lucidum strengthens the immune system and reduces the side effects of chemo- and radiotherapy. We investigated the possible genotoxic and antigenotoxic effects of the aqueous extract of wild-grown G. lucidum from Turkey using the HET-MN test. Three different doses of aqueous extract of G. lucidum, 50 µg/egg vitamin C as an antigenotoxic agent and 50 µg/egg cyclophosphamide as a genotoxic compound were injected separately or together into fertilized chicken eggs at incubation day 8. Embryonic peripheral blood smears were prepared and stained with a modified May-Grünwald-Giemsa method on incubation day 11. The frequencies of MN and nuclear abnormalities in erythrocytes were determined using light microscopy. Although the aqueous extract G. lucidum exhibited no genotoxic effect, it did exhibit an antigenotoxic effect. Our findings suggest that G. lucidum extract is a valuable natural antigenotoxic agent.
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Affiliation(s)
- B Çelik
- Department of Biology, Faculty of Science, Selçuk University, Selçuklu, Konya, Turkey
| | - H Özparlak
- Department of Biology, Faculty of Science, Selçuk University, Selçuklu, Konya, Turkey
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MAGAYE RUTH, ZHAO JINSHUN, BOWMAN LINDA, DING MIN. Genotoxicity and carcinogenicity of cobalt-, nickel- and copper-based nanoparticles. Exp Ther Med 2012; 4:551-561. [PMID: 23170105 PMCID: PMC3501377 DOI: 10.3892/etm.2012.656] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Accepted: 07/31/2012] [Indexed: 01/06/2023] Open
Abstract
The nanotechnology industry has matured and expanded at a rapid pace in the last decade, leading to the research and development of nanomaterials with enormous potential. The largest source of these nanomaterials is the transitional metals. It has been revealed that numerous properties of these nano-sized elements are not present in their bulk states. The nano size of these particles means they are easily transported into biological systems, thus, raising the question of their effects on the susceptible systems. Although advances have been made and insights have been gained on the effect of transitional metals on susceptible biological systems, there still is much ground to be covered, particularly with respect to our knowledge on the genotoxic and carcinogenic effects. Therefore, this review intends to summarize the current knowledge on the genotoxic and carcinogenic potential of cobalt-, nickel- and copper-based nanoparticles indicated in in vitro and in vivo mammalian studies. In the present review, we briefly state the sources, use and exposure routes of these nanoparticles and summarize the current literature findings on their in vivo and in vitro genotoxic and carcinogenic effects. Due to the increasing evidence of their role in carcinogenicity, we have also included studies that have reported epigenetic factors, such as abnormal apoptosis, enhanced oxidative stress and pro-inflammatory effects involving these nanoparticles.
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Affiliation(s)
- RUTH MAGAYE
- Department of Preventive Medicine of the Medical School, Zhejiang Provincial Key Laboratory of Pathological and Physiological Technology, Ningbo University, Ningbo, Zhejiang 315211,
P.R. China
| | - JINSHUN ZHAO
- Department of Preventive Medicine of the Medical School, Zhejiang Provincial Key Laboratory of Pathological and Physiological Technology, Ningbo University, Ningbo, Zhejiang 315211,
P.R. China
| | - LINDA BOWMAN
- Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505,
USA
| | - MIN DING
- Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505,
USA
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Oguz EO, Yuksel H, Enli Y, Tufan AC, Turgut G. The effects of copper sulfate on liver histology and biochemical parameters of term Ross broiler chicks. Biol Trace Elem Res 2010; 133:335-41. [PMID: 19597723 DOI: 10.1007/s12011-009-8447-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Accepted: 06/24/2009] [Indexed: 11/26/2022]
Abstract
Copper is an essential trace element that is extremely toxic to organisms and organs at high doses. We have investigated the histological and biochemical effects of a toxic dose of copper sulfate on the liver of term Ross broiler chicks. Fertilized eggs were divided into three groups: experimental, injected with 50 mcg/0.1 ml copper sulfate in the air chambers on day 1; sham, injected with 0.1 ml saline; and control, no injection. Term chicks were killed and their livers investigated histologically, with hematoxylin-eosin-stained sections examined under light microscopy, and biochemically, for malondialdehyde and glutathione levels. Histological examinations showed copper-treated samples with granular degeneration and necrosis of hepatocytes and impairment to the cell lining of the remark cords. The samples had a congestive appearance, with blood in the vena centralis and sinusoids, slight connective tissue increase, and lymphocyte infiltration. Control and sham group sections had normal appearances. As oxidative damage parameters, in the copper-treated group, malondialdehyde levels were increased and glutathione levels decreased. In the sham and control groups, there were no significant differences. At this toxic dose, copper sulfate shows oxidative damage according to the histology of term chick liver that are confirmed biochemically by the changes in malondialdehyde and glutathione levels.
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Affiliation(s)
- Emin Oguzhan Oguz
- Department of Histology & Embryology, Faculty of Medicine, Pamukkale University, Gunes Binasi, Bursa Cad. No.125, 20070, Kinikli, Denizli, Turkey.
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DNA damage induced by genotoxicants in zebrafish (Danio rerio) embryos after contact exposure to freeze-dried sediment and sediment extracts from Laguna Lake (The Philippines) as measured by the comet assay. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2008; 650:1-14. [DOI: 10.1016/j.mrgentox.2007.09.009] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2006] [Revised: 07/21/2007] [Accepted: 09/17/2007] [Indexed: 11/20/2022]
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Arkhipchuk VV, Garanko NN. Using the nucleolar biomarker and the micronucleus test on in vivo fish fin cells. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2005; 62:42-52. [PMID: 15978290 DOI: 10.1016/j.ecoenv.2005.01.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2004] [Revised: 12/18/2004] [Accepted: 01/19/2005] [Indexed: 05/03/2023]
Abstract
This study was aimed at developing the nucleolar biomarker and the micronucleus test on in vivo fish fin cells for assessing water cytotoxicity and genotoxicity. Both biomarkers can be used either jointly or separately on fins of the same fish during the experiment. For studying the nucleolar characteristics, small pieces of the fin edge were cut several times during 30-180 min of fish exposure. For micronucleus testing, the fin tissue regenerating after its cutting was investigated after 2-5 days of fish incubation. Effects of copper (0.1 and 2.5 mg/L), cadmium (0.005 and 1.0 mg/L) ions and chloral hydrate (400 and 800 mg/L) solutions were studied on cells of common carp (Cyprinus carpio L.), crucian carp (Carassius auratus gibelio Bloch.), and Mozambique tilapia (Tilapia (Sautherodon) mossambica) using a set of nucleolar characteristics (the number of nucleoli per cell, the size of a single nucleolus, and the percentage of cells with heteromorphic paired nucleoli) and the frequencies of cells with micronuclei and double nuclei. Substantial changes in parameters of nucleolar activity of fin cells were found to be caused by cadmium and copper impact. In comparison to blood cells, gill and fin cells were more sensitive as demonstrated by their nuclear damages after the chloral hydrate influence. Fin cells were useful to determine periodically cytotoxic and genotoxic effects of organic and inorganic substances in the same individual fish without any disruption of its physiological functions.
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Affiliation(s)
- V V Arkhipchuk
- Laboratory of Biomarkers and Biotesting, Institute of Colloid Chemistry and Water Chemistry, Kiev, Ukraine.
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White PA, Claxton LD. Mutagens in contaminated soil: a review. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2004; 567:227-345. [PMID: 15572286 DOI: 10.1016/j.mrrev.2004.09.003] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The intentional and accidental discharges of toxic pollutants into the lithosphere results in soil contamination. In some cases (e.g., wood preserving wastes, coal-tar, airborne combustion by-products), the contaminated soil constitutes a genotoxic hazard. This work is a comprehensive review of published information on soil mutagenicity. In total, 1312 assessments of genotoxic activity from 118 works were examined. The majority of the assessments (37.6%) employed the Salmonella mutagenicity test with strains TA98 and/or TA100. An additional 37.6% of the assessments employed a variety of plant species (e.g., Tradescantia clone 4430, Vicia faba, Zea mays, Allium cepa) to assess mutagenic activity. The compiled data on Salmonella mutagenicity indicates significant differences (p<0.0001) in mean potency (revertents per gram dry weight) between industrial, urban, and rural/agricultural sites. Additional analyses showed significant empirical relationships between S9-activated TA98 mutagenicity and soil polycyclic aromatic hydrocarbon (PAH) concentration (r2=0.19 to 0.25, p<0.0001), and between direct-acting TA98 mutagenicity and soil dinitropyrene (DNP) concentration (r2=0.87, p<0.0001). The plant assay data revealed excellent response ranges and significant differences between heavily contaminated, industrial, rural/agricultural, and reference sites, for the anaphase aberration in Allium cepa (direct soil contact) and the waxy locus mutation assay in Zea mays (direct soil contact). The Tradescantia assays appeared to be less responsive, particularly for exposures to aqueous soil leachates. Additional data analyses showed empirical relationships between anaphase aberrations in Allium, or mutations in Arabidopsis, and the 137Cs contamination of soils. Induction of micronuclei in Tradescantia is significantly related to the soil concentration of several metals (e.g., Sb, Cu, Cr, As, Pb, Cd, Ni, Zn). Review of published remediation exercises showed effective removal of genotoxic petrochemical wastes within one year. Remediation of more refractory genotoxic material (e.g., explosives, creosote) frequently showed increases in mutagenic hazard that remained for extended periods. Despite substantial contamination and mutagenic hazards, the risk of adverse effect (e.g., mutation, cancer) in humans or terrestrial biota is difficult to quantify.
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Affiliation(s)
- Paul A White
- Mutagenesis Section, Safe Environments Program, Health Canada, Tunney's Pasture 0803A, Ottawa, Ont., Canada K1A 0L2.
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Guecheva T, Henriques JA, Erdtmann B. Genotoxic effects of copper sulphate in freshwater planarian in vivo, studied with the single-cell gel test (comet assay). Mutat Res 2001; 497:19-27. [PMID: 11525904 DOI: 10.1016/s1383-5718(01)00244-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The alkaline single-cell gel electrophoresis, or comet assay, was used to evaluate the genotoxic potential of copper sulphate in planarians. Concentration-related increase in DNA damage was induced after 2h and 7 days exposure to CuSO4 dissolved in culture water. To study the influence of copper ions on the persistence of mutagen-induced DNA lesions, planarians were treated with methyl methanesulphonate (MMS), and further incubated in the absence (post-incubation) or presence (post-treatment) of CuSO4. After 2h of post-treatment enhanced persistence of DNA effects in relation to the corresponding post-incubation value was detected, which indicate inhibition of DNA repair by CuSO4. At 4h an increase of DNA migration in relation to the 2h value was observed, which is significant for the post-incubation group. After 24h, DNA damage decreased but was still significantly elevated in relation to the control. From our results, we conclude that planarians are suitable organisms for in vivo detection of copper genotoxicity in the comet assay, and can be used to assess both acute and chronic exposure to this chemical in aquatic ecosystems. The inhibition effect of copper ions on repair of MMS-induced DNA damage suggests that copper could modulate the genotoxic effects associated with complex mixture exposure in the environment.
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Affiliation(s)
- T Guecheva
- Departamento de Biofísica, Centro de Biotecnologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul (UFRGS), Prédio 43422, Caixa Postal 15093, CEP 91501-970, RS, Porto Alegre, Brazil.
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Sanchez-Galan S, Linde AR, Ayllon F, Garcia-Vazquez E. Induction of micronuclei in eel (Anguilla anguilla L.) by heavy metals. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2001; 49:139-143. [PMID: 11386727 DOI: 10.1006/eesa.2001.2048] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Micronucleus test was performed in situ on eels (Anguilla anguilla) from river sites with different levels of heavy metal pollution (cadmium and mercury). Cadmium content in eel liver but not micronuclei averages in kidney were associated with cadmium content in sediments. Mercury content in liver was not significantly associated with mercury content in sediments. Both cadmium and mercury induced micronuclei expression in eels when injected, the concentration tested being 1.7 mg metal/kg body weight and the micronuclei induction being 2.64 and 2.35 micronuclei per 1000 cells for cadmium and mercury respectively. It was concluded that these heavy metals are genotoxic for European eel, that eel liver metal content is a sensitive indicator for environmental monitoring of cadmium pollution, and that the micronuclei scores in eels are not a sensitive method to detect heavy metals pollution in freshwater ecosytems.
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Affiliation(s)
- S Sanchez-Galan
- Departamento Biologia Funcional, Facultad Medicina, Universidad Oviedo, C/J. Claveria, s/n, Oviedo, 33006, Spain
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Sanchez-Galan S, Linde AR, Garcia-Vazquez E. Brown trout and European minnow as target species for genotoxicity tests: differential sensitivity to heavy metals. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 1999; 43:301-304. [PMID: 10381308 DOI: 10.1006/eesa.1999.1794] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Brown trout (Salmo trutta) and European minnow (Phoxinus phoxinus) were evaluated as target species to carry out genotoxicity tests. Assessment was made of their relative abundance in wild; their distribution areas; and their sensitivity to heavy metals, intraperitoneally exposing individuals of both species to a low dose (1.7 mg/kg body weight) of different heavy metals. Micronuclei were scored in renal erythrocytes 24 h after treatment. Cadmium chloride significantly induced micronuclei in both species whereas mercury nitrate induced micronuclei increase only in brown trout. Brown trout is abundant, present in all studied freshwater ecosystems, and more sensitive to toxic heavy metals than minnow; therefore it is presented as a target species for studies on heavy metal genotoxicity.
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Affiliation(s)
- S Sanchez-Galan
- Departamento de Biologia Funcional, Facultad de Medicina, Universidad de Oviedo, C/Julian Claveria s/n, Oviedo, 33006, Spain
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Verhaegh GW, Richard MJ, Hainaut P. Regulation of p53 by metal ions and by antioxidants: dithiocarbamate down-regulates p53 DNA-binding activity by increasing the intracellular level of copper. Mol Cell Biol 1997; 17:5699-706. [PMID: 9315628 PMCID: PMC232418 DOI: 10.1128/mcb.17.10.5699] [Citation(s) in RCA: 144] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Mutations in the p53 tumor suppressor gene frequently fall within the specific DNA-binding domain and prevent the molecule from transactivating normal targets. DNA-binding activity is regulated in vitro by metal ions and by redox conditions, but whether these factors also regulate p53 in vivo is unclear. To address this question, we have analyzed the effect of pyrrolidine dithiocarbamate (PDTC) on p53 DNA-binding activity in cell lines expressing wild-type p53. PDTC is commonly regarded as an antioxidant, but it can also bind and transport external copper ions into cells and thus exert either pro- or antioxidant effects in different situations. We report that PDTC, but not N-acetyl-L-cysteine, down-regulated the specific DNA-binding activity of p53. Loss of DNA binding correlated with disruption of the immunologically "wild-type" p53 conformation. Using different chelators to interfere with copper transport by PDTC, we found that bathocuproinedisulfonic acid (BCS), a non-cell-permeable chelator of Cu1+, prevented both copper import and p53 down-regulation. In contrast, 1,10-orthophenanthroline, a cell-permeable chelator of Cu2+, promoted the redox activity of copper and up-regulated p53 DNA-binding activity through a DNA damage-dependent pathway. We have previously reported that p53 protein binds copper in vitro in the form of Cu1+ (P. Hainaut, N. Rolley, M. Davies, and J. Milner, Oncogene 10:27-32, 1995). The data reported here indicate that intracellular levels and redox activity of copper are critical for p53 protein conformation and DNA-binding activity and suggest that copper ions may participate in the physiological control of p53 function.
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Affiliation(s)
- G W Verhaegh
- Unit of Mechanisms of Carcinogenesis, International Agency for Research on Cancer, Lyon, France
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