1
|
Quantitative risk-benefit assessment of Portuguese fish and other seafood species consumption scenarios. Br J Nutr 2022; 128:1997-2010. [PMID: 34872627 DOI: 10.1017/s0007114521004773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Portugal has high fish/seafood consumption, which may have both risks and benefits. This study aims to quantify the net health impact of hypothetical scenarios of fish/seafood consumption in the Portuguese population using a risk-benefit assessment methodology. Consumption data from the National Food, Nutrition and Physical Activity Survey 2015-2016 (n 5811) were used to estimate the mean exposure to methylmercury and EPA + DHA in the current and the alternative scenarios considered. Alternative scenarios (alt) were modelled using probabilistic approaches to reflect substitutions from the current consumption in the type of fish/seafood (alt1: excluding predatory fishes; alt2: including only methylmercury low-level fishes) or in the frequency of weekly fish/seafood consumption (alt3 to alt6: 1, 3, 5 or 7 times a week, replacing fish/seafood meals with meat or others). The overall health impact of these scenarios was quantified using disability-adjusted life years (DALY). In the Portuguese population, about 11 450 DALY could be prevented each year if the fish/seafood consumption increased to a daily basis. However, such a scenario would result in 1398 extra DALY considering the consumption by pregnant women and the respective risk on fetal neurodevelopment. Our findings support a recommendation to increase fish/seafood consumption up to 7 times/week. However, for pregnant women and children, special considerations must be proposed to avoid potential risks on fetal neurodevelopment due to methylmercury exposure.
Collapse
|
2
|
Dolgova NV, Nehzati S, MacDonald TC, Summers KL, Crawford AM, Krone PH, George GN, Pickering IJ. Disruption of selenium transport and function is a major contributor to mercury toxicity in zebrafish larvae. Metallomics 2020; 11:621-631. [PMID: 30688331 DOI: 10.1039/c8mt00315g] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Mercury is one of the most toxic elements threatening the biosphere, with levels steadily rising due to both natural and human activities. Selenium is an essential micronutrient, required for normal development and functioning of many organisms. While selenium is known to counteract mercury's toxicity under some conditions, to date information about the mercury-selenium relationship is fragmented and often controversial. As part of a systematic study of mercury and selenium interactions, zebrafish (Danio rerio) larvae (a model verterbrate) were exposed to methylmercury chloride or mercuric chloride. The influence of pre- and post-treatment of selenomethionine on the level and distribution of mercury and selenium in the brain and eye sections, as well as on toxicity, were examined. Selenomethionine treatment decreased the amount of maternally transfered mercury in the larval brain. Selenomethionine treatment prior to exposure to mercuric chloride increased both mercury and selenium levels in the brain but decreased their toxic effects. Conversely, methylmercury levels were not changed as a result of selenium pre-treatment, while toxicity was increased. Strikingly, both forms of mercury severely disrupted selenium metabolism, not only by depleting selenium levels due to formation of Hg-Se complexes, but also by blocking selenium transport into and out of tissues, suggesting that restoring normal selenium levels by treating the organism with selenium after mercury exposure may not be possible. Disruption of selenium metabolism by mercury may lead to disruption in function of selenoproteins. Indeed, the production of thyroid hormones by selenoprotein deiodinases was found to be severely impaired as a result of mercury exposure, with selenomethionine not always being a suitable source of selenium to restore thyroid hormone levels.
Collapse
Affiliation(s)
- Natalia V Dolgova
- Molecular and Environment Sciences Group, Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada.
| | | | | | | | | | | | | | | |
Collapse
|
3
|
Sharma N, Kumar S, Kumar S, Mehta SK, Bhasin KK. Synthesis and characterization of fused imidazole heterocyclic selenoesters and their application for chemical detoxification of HgCl2. NEW J CHEM 2018. [DOI: 10.1039/c7nj03908e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Selenoester derivatives of imidazo[1,2-a]pyridine/imidazo[1,2-a]pyrimidine has been synthesized by the reaction of sodium selenocarboxylates with 2-(chloromethyl)imidazo[1,2-a]pyridine/pyrimidine.
Collapse
Affiliation(s)
- Nidhi Sharma
- Department of Chemistry and Centre for Advanced Studies in Chemistry
- Panjab University
- Chandigarh
- India
| | - Sanjeev Kumar
- Department of Chemistry and Centre for Advanced Studies in Chemistry
- Panjab University
- Chandigarh
- India
| | - Sangit Kumar
- Indian Institute of Science Education and Research (IISER)
- Bhopal
- India
| | - S. K. Mehta
- Department of Chemistry and Centre for Advanced Studies in Chemistry
- Panjab University
- Chandigarh
- India
| | - K. K. Bhasin
- Department of Chemistry and Centre for Advanced Studies in Chemistry
- Panjab University
- Chandigarh
- India
| |
Collapse
|
4
|
Branco V, Caito S, Farina M, Teixeira da Rocha J, Aschner M, Carvalho C. Biomarkers of mercury toxicity: Past, present, and future trends. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2017; 20:119-154. [PMID: 28379072 PMCID: PMC6317349 DOI: 10.1080/10937404.2017.1289834] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Mercury (Hg) toxicity continues to represent a global health concern. Given that human populations are mostly exposed to low chronic levels of mercurial compounds (methylmercury through fish, mercury vapor from dental amalgams, and ethylmercury from vaccines), the need for more sensitive and refined tools to assess the effects and/or susceptibility to adverse metal-mediated health risks remains. Traditional biomarkers, such as hair or blood Hg levels, are practical and provide a reliable measure of exposure, but given intra-population variability, it is difficult to establish accurate cause-effect relationships. It is therefore important to identify and validate biomarkers that are predictive of early adverse effects prior to adverse health outcomes becoming irreversible. This review describes the predominant biomarkers used by toxicologists and epidemiologists to evaluate exposure, effect and susceptibility to Hg compounds, weighing on their advantages and disadvantages. Most importantly, and in light of recent findings on the molecular mechanisms underlying Hg-mediated toxicity, potential novel biomarkers that might be predictive of toxic effect are presented, and the applicability of these parameters in risk assessment is examined.
Collapse
Affiliation(s)
- Vasco Branco
- a Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia , Universidade de Lisboa , Lisboa , Portugal
| | - Sam Caito
- b Department of Molecular Pharmacology , Albert Einstein College of Medicine , Bronx , New York , USA
| | - Marcelo Farina
- c Departamento de Bioquímica, Centro de Ciências Biológicas , Universidade Federal de Santa Catarina , Florianópolis , Brazil
| | - João Teixeira da Rocha
- d Departamento Bioquímica e Biologia Molecular , Universidade Federal de Santa Maria , Santa Maria , RS , Brazil
| | - Michael Aschner
- b Department of Molecular Pharmacology , Albert Einstein College of Medicine , Bronx , New York , USA
| | - Cristina Carvalho
- a Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia , Universidade de Lisboa , Lisboa , Portugal
| |
Collapse
|
5
|
Selenium and mercury levels in rat liver slices co-treated with diphenyl diselenide and methylmercury. Biometals 2016; 29:543-50. [DOI: 10.1007/s10534-016-9936-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Accepted: 04/24/2016] [Indexed: 11/25/2022]
|
6
|
Olsvik PA, Amlund H, Sæle Ø, Ellingsen S, Skjaerven KH. Impact of dietary selenium on methylmercury toxicity in juvenile Atlantic cod: a transcriptional survey. CHEMOSPHERE 2015; 120:199-205. [PMID: 25062025 DOI: 10.1016/j.chemosphere.2014.06.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 05/05/2014] [Accepted: 06/14/2014] [Indexed: 06/03/2023]
Abstract
Selenium (Se) and its derivatives are known to have protective effects against mercury (Hg) toxicity in mammals. In this study we wanted to evaluate whether Se co-exposure affect the transcription of methylmercury (MeHg) toxicity-relevant genes in early life stages of fish. Juvenile Atlantic cod were exposed to regular feed (control), Se-spiked feed (3mg Se kg(-1)), MeHg-spiked feed (10mg Hg kg(-1)) or to Se- and MeHg-spiked feed (3mg Se kg(-1) and 10mg Hg kg(-1), respectively) for ten weeks. Liver tissue was harvested for transcriptional analysis when the fish were weighing 11.4 ± 3.2g. Accumulated levels of Hg in liver of the two groups of fish exposed to MeHg were 1.5mg Hg kg(-1) wet weight, or 44-fold higher than in the control group, while the Se concentrations differed with less than 2-fold between the fish groups. Selenium co-exposure had no effect on the accumulated levels of Hg in liver tissue; however, MeHg co-exposure reduced the accumulated level of Se. Dietary exposure to MeHg had no effect on fish growth. Interaction effects between Se and MeHg exposure were observed for the transcriptional levels of CAT, GPX1, GPX3, NFE2L2, UBA52, SEPP1 and DNMT1. Significant effects of MeHg exposure were seen for DNMT1 and PPARG, while effects of Se exposure were seen for GPX4B and SEPP1A, as well as for DNA methyltransferase activity. The transcriptional results suggest, by considering up-regulation as a proxy for negative impact and at the tested concentrations, a pro-oxidative effect of Se co-exposure with MeHg, rather than an antioxidative effect.
Collapse
Affiliation(s)
- Pål A Olsvik
- National Institute of Nutrition and Seafood Research, Nordnesboder 1-2, N-5005 Bergen, Norway.
| | - Heidi Amlund
- National Institute of Nutrition and Seafood Research, Nordnesboder 1-2, N-5005 Bergen, Norway
| | - Øystein Sæle
- National Institute of Nutrition and Seafood Research, Nordnesboder 1-2, N-5005 Bergen, Norway
| | - Ståle Ellingsen
- National Institute of Nutrition and Seafood Research, Nordnesboder 1-2, N-5005 Bergen, Norway
| | - Kaja H Skjaerven
- National Institute of Nutrition and Seafood Research, Nordnesboder 1-2, N-5005 Bergen, Norway
| |
Collapse
|
7
|
Dietary selenium protect against redox-mediated immune suppression induced by methylmercury exposure. Food Chem Toxicol 2014; 72:169-77. [DOI: 10.1016/j.fct.2014.07.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 06/20/2014] [Accepted: 07/14/2014] [Indexed: 12/24/2022]
|
8
|
Joshi D, Mittal DK, Shukla S, Srivastav AK, Srivastav SK. Methylmercury toxicity: amelioration by selenium and water-soluble chelators as N-acetyl cysteine and dithiothreitol. Cell Biochem Funct 2014; 32:351-60. [DOI: 10.1002/cbf.3023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 10/27/2013] [Accepted: 11/26/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Deepmala Joshi
- Reproductive Biology and Toxicology Laboratory, UNESCO Satellite Center of Trace Element Research and School of Studies in Zoology; Jiwaji University; Gwalior Madhya Pradesh India
- Department of Zoology; DDU Gorakhpur University; Gorakhpur Uttar Pradesh India
| | - Deepak Kumar Mittal
- Reproductive Biology and Toxicology Laboratory, UNESCO Satellite Center of Trace Element Research and School of Studies in Zoology; Jiwaji University; Gwalior Madhya Pradesh India
| | - Sangeeta Shukla
- Reproductive Biology and Toxicology Laboratory, UNESCO Satellite Center of Trace Element Research and School of Studies in Zoology; Jiwaji University; Gwalior Madhya Pradesh India
| | | | | |
Collapse
|
9
|
Moreno F, García-Barrera T, Gómez-Jacinto V, Gómez-Ariza JL, Garbayo-Nores I, Vílchez-Lobato C. Antagonistic interaction of selenomethionine enantiomers on methylmercury toxicity in the microalgae Chlorella sorokiniana. Metallomics 2014; 6:347-55. [DOI: 10.1039/c3mt00296a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
10
|
Analytical and bioanalytical approaches to unravel the selenium–mercury antagonism: A review. Anal Chim Acta 2013; 801:1-13. [DOI: 10.1016/j.aca.2013.08.043] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 07/24/2013] [Accepted: 08/27/2013] [Indexed: 01/24/2023]
|
11
|
Sakamoto M, Yasutake A, Kakita A, Ryufuku M, Chan HM, Yamamoto M, Oumi S, Kobayashi S, Watanabe C. Selenomethionine protects against neuronal degeneration by methylmercury in the developing rat cerebrum. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:2862-2868. [PMID: 23398308 DOI: 10.1021/es304226h] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Although many experimental studies have shown that selenium protects against methylmercury (MeHg) toxicity at different end points, the direct interactive effects of selenium and MeHg on neurons in the brain remain unknown. Our goal is to confirm the protective effects of selenium against neuronal degeneration induced by MeHg in the developing postnatal rat brain using a postnatal rat model that is suitable for extrapolating the effects of MeHg to the fetal brain of humans. As an exposure source of selenium, we used selenomethionine (SeMet), a food-originated selenium. Wistar rats of postnatal days 14 were orally administered with vehicle (control), MeHg (8 mg Hg/kg/day), SeMet (2 mg Se/kg/day), or MeHg plus SeMet coexposure for 10 consecutive days. Neuronal degeneration and reactive astrocytosis were observed in the cerebral cortex of the MeHg-group but the symptoms were prevented by coexposure to SeMet. These findings serve as a proof that dietary selenium can directly protect neurons against MeHg toxicity in the mammalian brain, especially in the developing cerebrum.
Collapse
Affiliation(s)
- Mineshi Sakamoto
- National Institute for Minamata Disease, Minamata, Kumamoto 867-0008, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Petroni D, Tsai J, Agrawal K, Mondal D, George W. Low-dose methylmercury-induced oxidative stress, cytotoxicity, and tau-hyperphosphorylation in human neuroblastoma (SH-SY5Y) cells. ENVIRONMENTAL TOXICOLOGY 2012; 27:549-555. [PMID: 21254321 DOI: 10.1002/tox.20672] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 10/12/2010] [Accepted: 10/15/2010] [Indexed: 05/28/2023]
Abstract
Acute neurotoxic effects of high-dose methylmercury (MeHg) in humans have been well documented in the scientific literature. However, low-dose effects are less well described. This study was designed to evaluate the effects of low-dose MeHg (<100 nM) on human brain cells in a tissue culture model. Neuroblastoma (NB) cells (SH-SY5Y) were used in the cell culture model to study low-dose effects of MeHg on cell growth, cell survival, reactive oxygen species (ROS), and the phosphorylation of tau protein, as a measure of potential markers of cellular events associated with tauopathies. When cells were incubated in culture with MeHg (50 and 100 nM), there were significant decreases in cell viability as well as significant increase in ROS generation as determined by fluorescent dye analysis (H(2)DCFDA). Furthermore, a concomitant decrease in glutathione levels to 25% of control was observed at both 50 and 100 nM MeHg. In addition, the level of phosphorylated tau was significantly increased after treatment at both 50 and 100 nM MeHg, compared with controls. Pretreatment of NB cells with the antioxidant, N-acetylcysteine (1.25 mM) and the calpain inhibitor, MDL-28170 (10 μM), significantly attenuated the effects of MeHg (50 and 100 nM) on cell viability as well as on tau phosphorylation. These results indicate that low-dose MeHg toxicity may be related to an induction of tau phosphorylation through an oxidative stress-dependent mechanism and that blockade of this pathway may attenuate the toxic effects of MeHg.
Collapse
Affiliation(s)
- Daniel Petroni
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | | | | | | | | |
Collapse
|
13
|
Hernández-Moreno D, Pérez-López M, Míguez MP, Soler F, Jiménez B. Porphyrin levels in excreta of rabbit as non-destructive biomarkers of diazinon exposure. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2012; 34:466-472. [PMID: 22797323 DOI: 10.1016/j.etap.2012.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 06/14/2012] [Accepted: 06/23/2012] [Indexed: 06/01/2023]
Abstract
In the present study the effect of a chronic exposition to the organophosphorous pesticide diazinon on the porphyrin profile in feces of rabbit was evaluated, in order to validate the use of such molecules as non-destructive biomarkers for monitoring exposure of mammals to this environmental xenobiotic. Male and female (12:12) rabbits were exposed to oral single doses of diazinon, feces being sampled at every 10 days, till the end of the experience (30 days). HPLC method was validated from the results obtained, for detection of porphyrins in feces of mammals. Results revealed differences on the porphyrin profile between male and female, the most relevant differences associated to the uroporphyrin levels. In conclusion, porphyrin levels in rabbit's excreta may be used as indicators of exposure to such chemicals, thus providing a useful non-destructive method for monitoring exposure of animals to different environmental pollutants. However, the effect of gender should be taken into account when interpreting results.
Collapse
Affiliation(s)
- David Hernández-Moreno
- Toxicology Unit, Faculty of Veterinary Medicine, University of Extremadura, Avda de la Universidad s/n, 10003 Caceres, Spain.
| | - Marcos Pérez-López
- Toxicology Unit, Faculty of Veterinary Medicine, University of Extremadura, Avda de la Universidad s/n, 10003 Caceres, Spain.
| | - M Prado Míguez
- Toxicology Unit, Faculty of Veterinary Medicine, University of Extremadura, Avda de la Universidad s/n, 10003 Caceres, Spain
| | - Francisco Soler
- Toxicology Unit, Faculty of Veterinary Medicine, University of Extremadura, Avda de la Universidad s/n, 10003 Caceres, Spain
| | - Begoña Jiménez
- Department of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry, CSIC, Juan de la Cierva 3, 28006 Madrid, Spain
| |
Collapse
|
14
|
Biomarkers of adverse response to mercury: histopathology versus thioredoxin reductase activity. J Biomed Biotechnol 2012; 2012:359879. [PMID: 22888199 PMCID: PMC3408678 DOI: 10.1155/2012/359879] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Accepted: 05/25/2012] [Indexed: 11/24/2022] Open
Abstract
Exposure to mercury is normally assessed by measuring its accumulation in hair, blood or urine. Currently, the biomarkers of effect that have been proposed for mercurials, such as coproporphyrines or oxidative stress markers, are not sensitive enough and lack specificity. Selenium and selenoproteins are important targets for mercury and thioredoxin reductase (TrxR) in particular was shown to be very sensitive to mercury compounds both in vitro and in vivo. In this study we looked into the relation between the inhibition of thioredoxin reductase (TrxR) activity and histopathological changes caused by exposure to mercurials. Juvenile zeabra-seabreams were exposed to Hg2+ or MeHg for 28 days and histopathological changes were analyzed in the liver and kidney as well as TrxR activity. Both mercurials caused histopathological changes in liver and kidney, albeit Hg2+ caused more extensive and severe lesions. Likewise, both mercurials decreased TrxR activity, being Hg2+ a stronger inhibitor. Co-exposure to Hg2+ and Se fully prevented TrxR inhibition in the liver and reduced the severity of lesions in the organ. These results show that upon exposure to mercurials, histopathological alterations correlate with the level of TrxR activity and point to the potential use of this enzyme as a biomarker of mercury toxicity.
Collapse
|
15
|
Biological responses related to agonistic, antagonistic and synergistic interactions of chemical species. Anal Bioanal Chem 2012; 403:2237-53. [DOI: 10.1007/s00216-012-5776-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 01/17/2012] [Accepted: 01/20/2012] [Indexed: 01/26/2023]
|
16
|
Kaur P, Aschner M, Syversen T. Biochemical factors modulating cellular neurotoxicity of methylmercury. J Toxicol 2011; 2011:721987. [PMID: 21941541 PMCID: PMC3177097 DOI: 10.1155/2011/721987] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2011] [Revised: 06/28/2011] [Accepted: 07/13/2011] [Indexed: 11/30/2022] Open
Abstract
Methylmercury (MeHg), an environmental toxicant primarily found in fish and seafood, poses a dilemma to both consumers and regulatory authorities, given the nutritional benefits of fish consumption versus the possible adverse neurological damage. Several studies have shown that MeHg toxicity is influenced by a number of biochemical factors, such as glutathione (GSH), fatty acids, vitamins, and essential elements, but the cellular mechanisms underlying these complex interactions have not yet been fully elucidated. The objective of this paper is to outline the cellular response to dietary nutrients, as well as to describe the neurotoxic exposures to MeHg. In order to determine the cellular mechanism(s) of toxicity, the effect of pretreatment with biochemical factors (e.g., N-acetyl cysteine, (NAC); diethyl maleate, (DEM); docosahexaenoic acid, (DHA); selenomethionine, SeM; Trolox) and MeHg treatment on intercellular antioxidant status, MeHg content, and other endpoints was evaluated. This paper emphasizes that the protection against oxidative stress offered by these biochemical factors is among one of the major mechanisms responsible for conferring neuroprotection. It is therefore critical to ascertain the cellular mechanisms associated with various dietary nutrients as well as to determine the potential effects of neurotoxic exposures for accurately assessing the risks and benefits associated with fish consumption.
Collapse
Affiliation(s)
- Parvinder Kaur
- Department of Neuroscience, Norwegian University of Science and Technology, 7489 Trondheim, Norway
| | - Michael Aschner
- Departments of Pediatrics and Pharmacology and The Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, B-3307 Medical Center North, 1162 21st Avenue, Nashville, TN 37232-2495, USA
| | - Tore Syversen
- Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Olav Kyrres Gate 3, 7489 Trondheim, Norway
| |
Collapse
|
17
|
Carvalho CML, Lu J, Zhang X, Arnér ESJ, Holmgren A. Effects of selenite and chelating agents on mammalian thioredoxin reductase inhibited by mercury: implications for treatment of mercury poisoning. FASEB J 2010; 25:370-81. [PMID: 20810785 DOI: 10.1096/fj.10-157594] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Mercury toxicity is a highly interesting topic in biomedicine due to the severe endpoints and treatment limitations. Selenite serves as an antagonist of mercury toxicity, but the molecular mechanism of detoxification is not clear. Inhibition of the selenoenzyme thioredoxin reductase (TrxR) is a suggested mechanism of toxicity. Here, we demonstrated enhanced inhibition of activity by inorganic and organic mercury compounds in NADPH-reduced TrxR, consistent with binding of mercury also to the active site selenolthiol. On treatment with 5 μM selenite and NADPH, TrxR inactivated by HgCl(2) displayed almost full recovery of activity. Structural analysis indicated that mercury was complexed with TrxR, but enzyme-generated selenide removed mercury as mercury selenide, regenerating the active site selenocysteine and cysteine residues required for activity. The antagonistic effects on TrxR inhibition were extended to endogenous antioxidants, such as GSH, and clinically used exogenous chelating agents BAL, DMPS, DMSA, and α-lipoic acid. Consistent with the in vitro results, recovery of TrxR activity and cell viability by selenite was observed in HgCl(2)-treated HEK 293 cells. These results stress the role of TrxR as a target of mercurials and provide the mechanism of selenite as a detoxification agent for mercury poisoning.
Collapse
Affiliation(s)
- Cristina M L Carvalho
- Research Institute for Medicines and Pharmaceutical Sciences, Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal.
| | | | | | | | | |
Collapse
|
18
|
Moreno F, García-Barrera T, Gómez-Ariza JL. Simultaneous analysis of mercury and selenium species including chiral forms of selenomethionine in human urine and serum by HPLC column-switching coupled to ICP-MS. Analyst 2010; 135:2700-5. [DOI: 10.1039/c0an00090f] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
19
|
Koenig S, Savage C, Kim JP. Two novel non-destructive biomarkers to assess PAH-induced oxidative stress and porphyrinogenic effects in crabs. Biomarkers 2009; 14:452-64. [DOI: 10.3109/13547500903123026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
20
|
Folven KI, Glover CN, Malde MK, Lundebye AK. Does selenium modify neurobehavioural impacts of developmental methylmercury exposure in mice? ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2009; 28:111-119. [PMID: 21783990 DOI: 10.1016/j.etap.2009.03.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Revised: 03/03/2009] [Accepted: 03/04/2009] [Indexed: 05/31/2023]
Abstract
There is controversy as to whether low-level chronic exposure to methylmercury (MeHg) through maternal fish consumption may cause subtle effects in the developing child, owing in part to the potential ameliorating effects of beneficial seafood nutrients. The aim of the present investigation was to assess the ameliorating potential of selenium (Se; as the naturally occurring methionine complex) on the neurobehavioural toxicity of foodborne MeHg (as the naturally occurring cysteinate) in prenatally exposed mice. Pups from dams exposed to a diet containing 3mg/kg of MeHg fed throughout gestation showed delayed fur development and impaired performance in a motor function assessment. These effects were not apparent in pups born to dams concurrently exposed to Se (at 1.3mg/kg). These results, using natural dietary forms of the elements administered through the relevant exposure pathway, suggest only minor impacts of MeHgCys on neurobehaviour, and possible amelioration of these effects by Se.
Collapse
Affiliation(s)
- Kristin I Folven
- National Institute of Nutrition and Seafood Research (NIFES), Bergen, Norway
| | | | | | | |
Collapse
|
21
|
The in vitro effects of selenomethionine on methylmercury-induced neurotoxicity. Toxicol In Vitro 2009; 23:378-85. [DOI: 10.1016/j.tiv.2008.12.024] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 11/14/2008] [Accepted: 12/19/2008] [Indexed: 11/23/2022]
|
22
|
Diphenyl diselenide, a simple organoselenium compound, decreases methylmercury-induced cerebral, hepatic and renal oxidative stress and mercury deposition in adult mice. Brain Res Bull 2008; 79:77-84. [PMID: 19047014 DOI: 10.1016/j.brainresbull.2008.11.001] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Accepted: 11/04/2008] [Indexed: 11/22/2022]
Abstract
Oxidative stress has been pointed out as an important molecular mechanism in methylmercury (MeHg) intoxication. At low doses, diphenyl diselenide ((PhSe)2), a structurally simple organoselenium compound, has been shown to possess antioxidant and neuroprotective properties. Here we have examined the possible in vivo protective effect of diphenyl diselenide against the potential pro-oxidative effects of MeHg in mouse liver, kidney, cerebrum and cerebellum. The effects of MeHg exposure (2 mg/(kg day) of methylmercury chloride 10 ml/kg, p.o.), as well as the possible antagonist effect of diphenyl diselenide (1 and 0.4 mg/(kg day); s.c.) on body weight gain and on hepatic, cerebellar, cerebral and renal levels of thiobarbituric acid reactive substances (TBARS), non-protein thiols (NPSH), ascorbic acid content, mercury concentrations and activities of antioxidant enzymes (glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD)) were evaluated after 35 days of treatment. MeHg caused an increase in TBARS and decreased NPSH levels in all tissues. MeHg also induced a decrease in hepatic ascorbic acid content and in renal GPx and CAT activities. Diphenyl diselenide (1 mg/kg) conferred protection against MeHg-induced hepatic and renal lipid peroxidation and at both doses prevented the reduction in hepatic NPSH levels. Diphenyl diselenide also conferred a partial protection against MeHg-induced oxidative stress (TBARS and NPSH) in liver and cerebellum. Of particular importance, diphenyl diselenide decreased the deposition of Hg in cerebrum, cerebellum, kidney and liver. The present results indicate that diphenyl diselenide can protect against some toxic effects of MeHg in mice. This protection may be related to its antioxidant properties and its ability to reduce Hg body burden. We posit that formation of a selenol intermediate, which possesses high nucleophilicity and high affinity for MeHg, accounts for the ability of diphenyl diselenide to ameliorate MeHg-induced toxicity.
Collapse
|
23
|
Holmes AL, Wise SS, Goertz CEC, Dunn JL, Gulland FMD, Gelatt T, Beckmen KB, Burek K, Atkinson S, Bozza M, Taylor R, Zheng T, Zhang Y, Aboueissa AM, Wise JP. Metal tissue levels in Steller sea lion (Eumetopias jubatus) pups. MARINE POLLUTION BULLETIN 2008; 56:1416-1421. [PMID: 18599091 DOI: 10.1016/j.marpolbul.2008.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Revised: 05/07/2008] [Accepted: 05/12/2008] [Indexed: 05/26/2023]
Abstract
The endangered Western population of the Steller sea lion declined for three decades for uncertain reasons. We present baseline data of metal concentrations in pups as a first step towards investigating the potential threat of developmental exposures to contaminants. Seven metals were investigated: arsenic, cadmium, silver, aluminum, mercury, lead and vanadium. Vanadium was detected in only a single blubber sample. Mercury appears to be the most toxicologically significant metal with concentrations in the liver well above the current action level for mercury in fish. The concentrations of aluminum, arsenic, silver, cadmium and lead were present in one-fourth to two-thirds of all samples and were at either comparable or below concentrations previously reported. Neither gender nor region had a significant effect on metal burdens. Future work should consider metal concentrations in juveniles and adults and toxicological studies need to be performed to begin to assess the toxicity of these metals.
Collapse
Affiliation(s)
- Amie L Holmes
- Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth Street, Portland, ME 04104, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Carvalho CM, Chew EH, Hashemy SI, Lu J, Holmgren A. Inhibition of the Human Thioredoxin System. J Biol Chem 2008; 283:11913-23. [DOI: 10.1074/jbc.m710133200] [Citation(s) in RCA: 364] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
25
|
Carvalho CML, Matos AINM, Mateus ML, Santos APM, Batoreu MCC. High-fish consumption and risk prevention: assessment of exposure to methylmercury in Portugal. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2008; 71:1279-1288. [PMID: 18654900 DOI: 10.1080/15287390801989036] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The aim of this study was to evaluate the exposure to methylmercury (MeHg) of potential populations at risk living in Portugal. To ascertain youth exposure, a questionnaire was distributed to 300 students of a middle secondary school in Sesimbra and to 429 students studying in Canecas, selected as the control population. The average number of fish meals consumed by person was 4.1 and 3 per week in Sesimbra and Canecas, respectively. The subpopulations of high intake (PHI) corresponding to those ingesting 7 or more fish meals per week were also analyzed separately, with 17% of the students belonging to the PHI of Sesimbra versus 6.1% in Canecas. Socioeconomic aspects such as relative's professional involvement with fisheries correlated with the higher intakes in Sesimbra. Fish samples were collected in the dock of Sesimbra and total mercury (Hg) was determined by flow injection cold vapor atomic fluorescence spectroscopy (FI-CV-AFS). The mean value found for nonpredators was 0.035 microg/g. Dogfish specimens surpassed the legislated limit for predator species and increased the predators mean to 1 microg/g. The cross-sectional data were integrated with the fish analysis results to estimate the population exposure to MeHg. The indices of risk calculated for youth reached values of 4.5, demonstrating the existence of risk to a part of the population exceeding the provisional tolerable weekly intake (PTWI) level mandated by WHO (1.6 microg/kg bw). The results indicate that monitoring of Hg levels in fish is mandatory and counseling should be provided to populations at risk, encouraging them to prevent the risk.
Collapse
Affiliation(s)
- C M L Carvalho
- I-Med (CECF), Laboratory of Toxicology, Faculty of Pharmacy, University of Lisbon, Lisboa, Portugal.
| | | | | | | | | |
Collapse
|