1
|
McCarthy M, O'Halloran J, O'Brien NM, van Pelt FFNAM. Does the marine biotoxin okadaic acid cause DNA fragmentation in the blue mussel and the pacific oyster? MARINE ENVIRONMENTAL RESEARCH 2014; 101:153-160. [PMID: 25440785 DOI: 10.1016/j.marenvres.2014.09.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/19/2014] [Accepted: 09/28/2014] [Indexed: 06/04/2023]
Abstract
Two bivalve species of global economic importance: the blue mussel, Mytilus edulis and the pacific oyster, Crassostrea gigas were exposed in vivo, to the diarrhoetic shellfish toxin okadaic acid (OA), and impacts on DNA fragmentation were measured. Shellfish were exposed using two different regimes, the first was a single (24 h) exposure of 2.5 nM OA (∼0.1 μg/shellfish) and algal feed at the beginning of the trial (T0), after which shellfish were only fed algae. The second was daily exposure of shellfish to two different concentrations of OA mixed with the algal feed over 7 days; 1.2 nM OA (∼0.05 μg OA/shellfish/day) and 50 nM OA (∼2 μg OA/shellfish/day). Haemolymph and hepatopancreas cells were extracted following 1, 3 and 7 days exposure. Cell viability was measured using the trypan blue exclusion assay and remained above 85% for both cell types. DNA fragmentation was examined using the single-cell gel electrophoresis (comet) assay. A significant increase in DNA fragmentation was observed in the two cell types from both species relative to the controls. This increase was greater in the pacific oyster at the higher toxin concentration. However, there was no difference in the proportion of damage measured between the two cell types, and a classic dose response was not observed, increasing toxin concentration did not correspond to increased DNA fragmentation.
Collapse
Affiliation(s)
- Moira McCarthy
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland; Environmental Research Institute, University College Cork, Cork, Ireland.
| | - John O'Halloran
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland; Environmental Research Institute, University College Cork, Cork, Ireland
| | - Nora M O'Brien
- School of Food and Nutritional Sciences, University College Cork, Cork, Ireland
| | - Frank F N A M van Pelt
- Department of Pharmacology and Therapeutics, University College Cork, Cork, Ireland; Environmental Research Institute, University College Cork, Cork, Ireland
| |
Collapse
|
2
|
Munday R, Reeve J. Risk assessment of shellfish toxins. Toxins (Basel) 2013; 5:2109-37. [PMID: 24226039 PMCID: PMC3847717 DOI: 10.3390/toxins5112109] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 10/23/2013] [Accepted: 10/30/2013] [Indexed: 01/24/2023] Open
Abstract
Complex secondary metabolites, some of which are highly toxic to mammals, are produced by many marine organisms. Some of these organisms are important food sources for marine animals and, when ingested, the toxins that they produce may be absorbed and stored in the tissues of the predators, which then become toxic to animals higher up the food chain. This is a particular problem with shellfish, and many cases of poisoning are reported in shellfish consumers each year. At present, there is no practicable means of preventing uptake of the toxins by shellfish or of removing them after harvesting. Assessment of the risk posed by such toxins is therefore required in order to determine levels that are unlikely to cause adverse effects in humans and to permit the establishment of regulatory limits in shellfish for human consumption. In the present review, the basic principles of risk assessment are described, and the progress made toward robust risk assessment of seafood toxins is discussed. While good progress has been made, it is clear that further toxicological studies are required before this goal is fully achieved.
Collapse
Affiliation(s)
- Rex Munday
- AgResearch Ltd, Ruakura Research Centre, Private Bag 3123, Hamilton, New Zealand
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +64-7-838-5138; Fax: +64-7-838-5012
| | - John Reeve
- Ministry of Primary Industries, PO Box 2526, Wellington, New Zealand; E-Mail:
| |
Collapse
|
3
|
Valdiglesias V, Prego-Faraldo MV, Pásaro E, Méndez J, Laffon B. Okadaic acid: more than a diarrheic toxin. Mar Drugs 2013; 11:4328-49. [PMID: 24184795 PMCID: PMC3853731 DOI: 10.3390/md11114328] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 10/08/2013] [Accepted: 10/23/2013] [Indexed: 01/04/2023] Open
Abstract
Okadaic acid (OA) is one of the most frequent and worldwide distributed marine toxins. It is easily accumulated by shellfish, mainly bivalve mollusks and fish, and, subsequently, can be consumed by humans causing alimentary intoxications. OA is the main representative diarrheic shellfish poisoning (DSP) toxin and its ingestion induces gastrointestinal symptoms, although it is not considered lethal. At the molecular level, OA is a specific inhibitor of several types of serine/threonine protein phosphatases and a tumor promoter in animal carcinogenesis experiments. In the last few decades, the potential toxic effects of OA, beyond its role as a DSP toxin, have been investigated in a number of studies. Alterations in DNA and cellular components, as well as effects on immune and nervous system, and even on embryonic development, have been increasingly reported. In this manuscript, results from all these studies are compiled and reviewed to clarify the role of this toxin not only as a DSP inductor but also as cause of alterations at the cellular and molecular levels, and to highlight the relevance of biomonitoring its effects on human health. Despite further investigations are required to elucidate OA mechanisms of action, toxicokinetics, and harmful effects, there are enough evidences illustrating its toxicity, not related to DSP induction, and, consequently, supporting a revision of the current regulation on OA levels in food.
Collapse
Affiliation(s)
- Vanessa Valdiglesias
- Toxicology Unit, Department of Psychobiology, University of A Coruña, A Coruña E15071, Spain; E-Mails: (E.P.); (B.L.)
- Department of Cellular and Molecular Biology, University of A Coruna, A Coruña E15071, Spain; E-Mails: (M.V.P.-F.); (J.M.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +34-981167000; Fax: +34-981167172
| | - María Verónica Prego-Faraldo
- Department of Cellular and Molecular Biology, University of A Coruna, A Coruña E15071, Spain; E-Mails: (M.V.P.-F.); (J.M.)
| | - Eduardo Pásaro
- Toxicology Unit, Department of Psychobiology, University of A Coruña, A Coruña E15071, Spain; E-Mails: (E.P.); (B.L.)
| | - Josefina Méndez
- Department of Cellular and Molecular Biology, University of A Coruna, A Coruña E15071, Spain; E-Mails: (M.V.P.-F.); (J.M.)
| | - Blanca Laffon
- Toxicology Unit, Department of Psychobiology, University of A Coruña, A Coruña E15071, Spain; E-Mails: (E.P.); (B.L.)
| |
Collapse
|
4
|
Prado-Alvarez M, Flórez-Barrós F, Méndez J, Fernandez-Tajes J. Effect of okadaic acid on carpet shell clam (Ruditapes decussatus) haemocytes by in vitro exposure and harmful algal bloom simulation assays. Cell Biol Toxicol 2013; 29:189-97. [DOI: 10.1007/s10565-013-9246-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 04/25/2013] [Indexed: 11/30/2022]
|
5
|
Flórez-Barrós F, Prado-Alvarez M, Méndez J, Fernández-Tajes J. Evaluation of genotoxicity in gills and hemolymph of clam Ruditapes decussatus fed with the toxic dinoflagellate Prorocentrum lima. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2011; 74:971-979. [PMID: 21707422 DOI: 10.1080/15287394.2011.582025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Diarrheic shellfish poisoning (DSP) is a gastrointestinal (GIT) disease that appears a few hours after ingesting okadaic acid (OA)-contaminated mollusks; okadaic acid is present in dinoflagellates of the genera Dinophysis and Prorocentrum. Toxic manifestations occur all year round at a higher or lesser intensity, and as a consequence, extractive production factories need to be closed during these periods which affects the economy of aquaculture industries. Although the concentration of harmful algae is usually found at high levels in clam digestive gland, bivalve mortality was not increased. In this study, the genotoxic effects produced by OA in clam Ruditapes decussatus were determined using the comet assay. In vitro (exposing hemocytes to different concentrations of OA) and in vivo (feeding clams with toxic dinoflagellate Prorocentrum lima) experiments were conducted in order to determine the genotoxic effects of OA on bivalve cells. Hemocytes and gill cells were analyzed by in vivo and in vitro approaches. While the in vitro study showed a rapid effect of OA on hemocytes, data obtained in the in vivo experiment reflected contradictory results dependent upon the concentration of OA and cell type evaluated. An increase in DNA damage was observed at the lower concentration and only in gill tissue. The results obtained may contribute to a better understanding of the mechanisms underlying genotoxic effects induced by OA on bivalves.
Collapse
Affiliation(s)
- Fernanda Flórez-Barrós
- Department of Cell and Molecular Biology, Faculty of Sciences, University of A Coruña, Spain
| | | | | | | |
Collapse
|
6
|
Dominguez HJ, Paz B, Daranas AH, Norte M, Franco JM, Fernández JJ. Dinoflagellate polyether within the yessotoxin, pectenotoxin and okadaic acid toxin groups: Characterization, analysis and human health implications. Toxicon 2010; 56:191-217. [DOI: 10.1016/j.toxicon.2009.11.005] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 10/11/2009] [Accepted: 11/09/2009] [Indexed: 11/26/2022]
|
7
|
Valdiglesias V, Méndez J, Pásaro E, Cemeli E, Anderson D, Laffon B. Assessment of okadaic acid effects on cytotoxicity, DNA damage and DNA repair in human cells. Mutat Res 2010; 689:74-79. [PMID: 20621797 DOI: 10.1016/j.mrfmmm.2010.05.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 05/07/2010] [Accepted: 05/20/2010] [Indexed: 05/29/2023]
Abstract
Okadaic acid (OA) is a phycotoxin produced by several types of dinoflagellates causing diarrheic shellfish poisoning (DSP) in humans. Symptoms induced by DSP toxins are mainly gastrointestinal, but the intoxication does not appear to be fatal. Despite this, this toxin presents a potential threat to human health even at concentrations too low to induce acute toxicity, since previous animal studies have shown that OA has very potent tumour promoting activity. However, its concrete action mechanism has not been described yet and the results reported with regard to OA cytotoxicity and genotoxicity are often contradictory. In the present study, the genotoxic and cytotoxic effects of OA on three different types of human cells (peripheral blood leukocytes, HepG2 hepatoma cells, and SHSY5Y neuroblastoma cells) were evaluated. Cells were treated with a range of OA concentrations in the presence and absence of S9 fraction, and MTT test and Comet assay were performed in order to evaluate cytotoxicity and genotoxicity, respectively. The possible effects of OA on DNA repair were also studied by means of the DNA repair competence assay, using bleomycin as DNA damage inductor. Treatment with OA in absence of S9 fraction induced not statistically significant decrease in cell viability and significant increase in DNA damage in all cell types at the highest concentrations investigated. However, only SHSY5Y cells showed OA induced genotoxic and cytotoxic effects in presence of S9 fraction. Furthermore, we found that OA can induce modulations in DNA repair processes when exposure was performed prior to BLM treatment, in co-exposure, or during the subsequent DNA repair process.
Collapse
Affiliation(s)
- Vanessa Valdiglesias
- Toxicology Unit, Psychobiology Department, University of A Coruña, Edificio de Servicios Centrales de Investigación, Campus Elviña s/n, 15071 A Coruña, Spain
| | | | | | | | | | | |
Collapse
|
8
|
Hashizume T, Yoshitomi S, Asahi S, Matsumura S, Chatani F, Oda H. In vitro micronucleus test in HepG2 transformants expressing a series of human cytochrome P450 isoforms with chemicals requiring metabolic activation. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2009; 677:1-7. [DOI: 10.1016/j.mrgentox.2009.03.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2008] [Revised: 03/12/2009] [Accepted: 03/29/2009] [Indexed: 10/20/2022]
|
9
|
Souid-Mensi G, Moukha S, Mobio TA, Maaroufi K, Creppy EE. The cytotoxicity and genotoxicity of okadaic acid are cell-line dependent. Toxicon 2008; 51:1338-44. [DOI: 10.1016/j.toxicon.2008.03.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Revised: 02/25/2008] [Accepted: 03/03/2008] [Indexed: 11/26/2022]
|
10
|
Marine biotoxins in shellfish - okadaic acid and analogues - Scientific Opinion of the Panel on Contaminants in the Food chain. EFSA J 2008. [DOI: 10.2903/j.efsa.2008.589] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
11
|
Yauk CL, Polyzos A, Rowan-Carroll A, Kortubash I, Williams A, Kovalchuk O. Tandem repeat mutation, global DNA methylation, and regulation of DNA methyltransferases in cultured mouse embryonic fibroblast cells chronically exposed to chemicals with different modes of action. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2008; 49:26-35. [PMID: 18172875 DOI: 10.1002/em.20359] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Mutations at expanded simple tandem repeat (ESTR) DNA sequences provide a useful tool for screening germline mutation. However, the mechanisms resulting in induced mutations are unknown and provide an impediment to the utility of the method. Induced ESTR mutations arise through a nontargeted mechanism resulting in destabilization of the repeat locus. We hypothesized that alterations in DNA methylation, or in DNA methyltransferase expression, may be associated with this indirect mechanism of mutation. DNA mutation frequency was measured in C3H/10T1/2 mouse embryonic fibroblast cells following chronic exposure to six chemicals exhibiting different modes of genotoxic action: N-nitroso-N-ethylurea (ENU); benzo(a)pyrene (BaP); etoposide (ETOP); okadaic acid (OA); cisplatin (CisPt); and 5-azacytidine (5azadC). Induced mutation ranged from 2-fold (ENU, BaP, ETOP), to 1.3-1.4 fold (OA, 5azadC), to nonresponsive (CisPt). Global DNA methylation, measured using the cytosine extension assay, revealed hypomethylation following exposure to ENU and 5azadC, hypermethylation following BaP and OA exposure, and no change following treatment with ETOP or CisPt. DNA methyltransferase transcription (Dnmt1, Dnmt3a, Dnmt3b) was significantly affected by all treatments except ETOP, with the vast majority of changes being downregulation. There was no direct correlation between ESTR mutation, global methylation, or DNA methyltransferase transcription. However, 4/5 ESTR mutagens caused changes in global methylation, while the noninducer (CisPt) did not cause changes in methylation. We hypothesize that chemicals that modify chromatin conformation through changes in methylation may compromise the ability of mismatch repair enzymes (or other enzymes) to access and repair secondary structures that may form across ESTR loci resulting in mutation.
Collapse
Affiliation(s)
- Carole L Yauk
- Environmental Health Sciences and Research Bureau, Safe Environments Programme, Health Canada, Ottawa, Ontario, Canada.
| | | | | | | | | | | |
Collapse
|
12
|
Escoffier N, Gaudin J, Mezhoud K, Huet H, Chateau-Joubert S, Turquet J, Crespeau F, Edery M. Toxicity to medaka fish embryo development of okadaic acid and crude extracts of Prorocentrum dinoflagellates. Toxicon 2007; 49:1182-92. [PMID: 17382985 DOI: 10.1016/j.toxicon.2007.02.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Revised: 02/05/2007] [Accepted: 02/06/2007] [Indexed: 11/27/2022]
Abstract
Chronic and subchronic toxicity following exposure to the DSP (Diarrhetic shellfish poisoning) toxin okadaic acid (OA) is receiving increasing attention as a public human health biohazard. However information on ecological impacts induced by proliferation of the OA producing dinoflagellate Prorocentrum is scarce. In order to analyse the toxicity of these substances, in vivo experiments were conducted on medaka fish (Oryzias latipes) embryos used as an experimental model. The study was focused on two strains of benthic Prorocentrum species, P. arenarium and P. emarginatum, naturally found in the Indian Ocean. Sample extracts (crude extracts, CE) were obtained from algal cultures and their toxic potential was explored. Their OA (and derivatives) content was evaluated by two methods: one based on chemical analysis using HPLC-MS, the other based on screening the inhibiting effect on protein phosphatase PP2A. P. arenarium extracts inhibit PP2A and the active toxin was confirmed as being OA by HPLC-MS. In contrast, P. emarginatum showed negative results regardless of the method used. The development of medaka fish embryos kept in medium containing pure OA or Prorocentrum CE was examined. Survival rates were reduced up to 100% depending on the concentrations used of both OA and CE of P. arenarium, while no effect was observed with CE of P. emarginatum. Anatomopathological studies of surviving embryos indicate that OA treatment resulted in significant increases in liver and digestive tract areas compared to controls. P. arenarium treated surviving embryos exhibited significant quantitative increases of global body and vitellus areas. Together, our results indicate that the toxic effects to medaka embryos development of pure OA and P. arenarium extracts containing OA are distinguishable. The differences may indicate the presence of additional toxic substance(s) (or molecules able to modulate OA impact) in the P. arenarium CE that probably are not present in P. emarginatum.
Collapse
Affiliation(s)
- Nicolas Escoffier
- USM 0505 Ecosystèmes et Interactions Toxiques, Muséum National d'Histoire Naturelle, RDDM, 12 rue Buffon, F-75231, Paris Cedex 05, France
| | | | | | | | | | | | | | | |
Collapse
|