Abstract
Azaspiracids (AZAs) are marine biotoxins produced by the dinoflagellate Azadinium spinosum that accumulate in several shellfish species. Azaspiracid poisoning episodes have been described in humans due to ingestion of AZA-contaminated seafood. Therefore, the contents of AZA-1, AZA-2 and AZA-3, the best-known analogs of the group, in shellfish destined to human consumption have been regulated by food safety authorities of many countries to protect human health. In vivo and in vitro toxicological studies have described effects of AZAs at different cellular levels and on several organs, however, AZA target remains unknown. Very recently, AZAs have been demonstrated to block the hERG cardiac potassium channel. In this study, we explored the potential cardiotoxicity of AZA-2 in vivo. The effects of AZA-2 on rat electrocardiogram (ECG) and cardiac biomarkers were evaluated for cardiotoxicity signs besides corroborating the hERG-blocking activity of AZA-2. Our results demonstrated that AZA-2 does not induce QT interval prolongation on rat ECGs in vivo, in spite of being an in vitro blocker of the hERG cardiac potassium channel. However, AZA-2 alters the heart electrical activity causing prolongation of PR intervals and the appearance of arrhythmias. More studies will be needed to clarify the mechanism by which AZA-2 causes these ECG alterations; however, the potential cardiotoxicity of AZAs demonstrated in this in vivo study should be taken into consideration when evaluating the possible threat that these toxins pose to human health, mainly for individuals with pre-existing cardiovascular disease when regulated toxin limits are exceeded.
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References
Aasen JA, Espenes A et al (2010) Sub-lethal dosing of azaspiracid-1 in female NMRI mice. Toxicon 56(8):1419–1425
Alfonso A, Román Y et al (2005) Azaspiracid-4 inhibits Ca2+ entry by stored operated channels in human T lymphocytes. Biochem Pharmacol 69(11):1627–1636
Colman JR, Twiner MJ et al (2005) Teratogenic effects of azaspiracid-1 identified by microinjection of Japanese medaka (Oryzias latipes) embryos. Toxicon 45(7):881–890
EC (2004) Regulation (EC) No. 853/2004 of the European Parliament and of the Council of 29 April 2004 laying down specific hygiene rules for food animal origin. Off J Eur Commun L 134:55
EFSA (2008) Marine biotoxin in shellfish-azaspiracid group. Scientific opinion of the panel on contaminants in the food chain. EFSA J 723:1–52
EMEA (2005). ICH Topic S 7 B. The nonclinical evaluation of the potential for delayed ventricular repolarization (QT interval prolongation) by human pharmaceuticals. http://www.emea.europa.eu/pdfs/human/ich/042302en.pdf
Farraj AK, Hazari MS et al (2011) The utility of the small rodent electrocardiogram in toxicology. Toxicol Sci 121(1):11–30
Furey A, O’Doherty S et al (2010) Azaspiracid poisoning (AZP) toxins in shellfish: toxicological and health considerations. Toxicon 56(2):173–190
Gintant G (2011) An evaluation of hERG current assay performance: translating preclinical safety studies to clinical QT prolongation. Pharmacol Ther 129(2):109–119
Gintant GA, Su Z et al (2006) Utility of hERG assays as surrogate markers of delayed cardiac repolarization and QT safety. Toxicol Pathol 34(1):81–90
Guo L, Guthrie H (2005) Automated electrophysiology in the preclinical evaluation of drugs for potential QT prolongation. J Pharmacol Toxicol Methods 52(1):123–135
Guth BD (2007) Preclinical cardiovascular risk assessment in modern drug development. Toxicol Sci 97(1):4–20
Hancox JC, Levi AJ et al (1998) Time course and voltage dependence of expressed HERG current compared with native “rapid” delayed rectifier K current during the cardiac ventricular action potential. Pflugers Arch 436(6):843–853
Hancox JC, McPate MJ et al (2008) The hERG potassium channel and hERG screening for drug-induced torsades de pointes. Pharmacol Ther 119(2):118–132
Hoffmann P, Warner B (2006) Are hERG channel inhibition and QT interval prolongation all there is in drug-induced torsadogenesis? A review of emerging trends. J Pharmacol Toxicol Methods 53(2):87–105
Ito E, Satake M et al (2000) Multiple organ damage caused by a new toxin azaspiracid, isolated from mussels produced in Ireland. Toxicon 38(7):917–930
Ito E, Satake M et al (2002) Chronic effects in mice caused by oral administration of sublethal doses of azaspiracid, a new marine toxin isolated from mussels. Toxicon 40(2):193–203
James KJ, Fidalgo Saez MJ et al (2004) Azaspiracid poisoning, the food-borne illness associated with shellfish consumption. Food Addit Contam 21(9):879–892
Katchman AN, Koerner J et al (2006) Comparative evaluation of HERG currents and QT intervals following challenge with suspected torsadogenic and nontorsadogenic drugs. J Pharmacol Exp Ther 316(3):1098–1106
Keating MT, Sanguinetti MC (2001) Molecular and cellular mechanisms of cardiac arrhythmias. Cell 104(4):569–580
Kettenhofen R, Bohlen H (2008) Preclinical assessment of cardiac toxicity. Drug Discov Today 13(15–16):702–707
Kmecova J, Klimas J (2010) Heart rate correction of the QT duration in rats. Eur J Pharmacol 641(2–3):187–192
Lorsheyd A, de Lange DW et al (2005) PR and OTc interval prolongation on the electrocardiogram after binge drinking in healthy individuals. Neth J Med 63(2):59–63
McMahon T, Silke J (1996) Winter toxicity of unknown aetiology in mussels. Harmful Algae 14:2
Nicolaou KC, Frederick MO et al (2006) Second-generation total synthesis of azaspiracids-1, -2, and -3. Chem Asian J 1(1–2):245–263
O’Brien PJ (2008) Cardiac troponin is the most effective translational safety biomarker for myocardial injury in cardiotoxicity. Toxicology 245(3):206–218
Ofuji K, Satake M et al (1999) Two analogs of azaspiracid isolated from mussels, Mytilus edulis, involved in human intoxication in Ireland. Nat Toxins 7(3):99–102
Ozer J, Ratner M et al (2008) The current state of serum biomarkers of hepatotoxicity. Toxicology 245(3):194–205
Perry M, Sanguinetti M et al (2010) Revealing the structural basis of action of hERG potassium channel activators and blockers. J Physiol 588(Pt 17):3157–3167
Polak S, Wisniowska B et al (2009) Collation, assessment and analysis of literature in vitro data on hERG receptor blocking potency for subsequent modeling of drugs’ cardiotoxic properties. J Appl Toxicol 29(3):183–206
Priest BT, Bell IM et al (2008) Role of hERG potassium channel assays in drug development. Channels (Austin) 2(2):87–93
Redfern WS, Carlsson L et al (2003) Relationships between preclinical cardiac electrophysiology, clinical QT interval prolongation and torsade de pointes for a broad range of drugs: evidence for a provisional safety margin in drug development. Cardiovasc Res 58(1):32–45
Sanguinetti MC, Jiang C et al (1995) A mechanistic link between an inherited and an acquired cardiac arrhythmia: HERG encodes the IKr potassium channel. Cell 81(2):299–307
Satake M, Ofuji K et al (1998) Azaspiracid, a new marine toxin having unique spiro ring assemblies, isolated from Irish mussels, Mytilus edulis. J Am Chem Soc 120(38):9967–9968
Shah RR (2005) Drug-induced QT interval prolongation–regulatory guidance and perspectives on hERG channel studies. Novartis Found Symp 266:251–280
Stummann TC, Beilmann M et al (2009) Report and recommendations of the workshop of the European centre for the validation of alternative methods for drug-induced cardiotoxicity. Cardiovasc Toxicol 9(3):107–125
Su Z, Limberis J et al (2009) Electrophysiologic characterization of a novel hERG channel activator. Biochem Pharmacol 77(8):1383–1390
Twiner MJ, Hess P et al (2005) Cytotoxic and cytoskeletal effects of azaspiracid-1 on mammalian cell lines. Toxicon 45(7):891–900
Twiner MJ, Doucette GJ et al (2012) Marine algal toxin azaspiracid is an open-state blocker of HERG potassium channels. Chem Res Toxicol 25(9):1975–1984
Vilariño N, Nicolaou KC et al (2007) Irreversible cytoskeletal disarrangement is independent of caspase activation during in vitro azaspiracid toxicity in human neuroblastoma cells. Biochem Pharmacol 74(2):327–335
Walker DB (2006) Serum chemical biomarkers of cardiac injury for nonclinical safety testing. Toxicol Pathol 34(1):94–104
Zeltser D, Justo D et al (2004) Drug-induced atrioventricular block: prognosis after discontinuation of the culprit drug. J Am Coll Cardiol 44(1):105–108
Acknowledgments
This work was funded with the following FEDER cofunded-grants: From Ministerio de Ciencia y Tecnología, Spain: SAF2009-12581 (subprograma NEF), AGL2009 13581-CO2-01, TRA2009-0189, AGL2010-17875. From Xunta de Galicia, Spain: GRC 2010/10, and PGDIT 07MMA006261PR, PGIDIT (INCITE) 09MMA003261PR, PGDIT (INCITE) 09261080PR, 2009/XA044 and 10PXIB261254 PR. From EU VIIth Frame Program: 211326-CP (CONffIDENCE), 265896 BAMMBO, 265409 μAQUA, and 262649 BEADS, 312184 PharmaSea, 315285 Ciguatools. From the Atlantic Area Programme (Interreg IVB Trans-national): 2009-1/117 Pharmatlantic. From the National Institutes of Health (USA) (Grant ES013314, to K.C.N.). No competing financial interests.
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Ferreiro, S.F., Vilariño, N., Carrera, C. et al. In vivo arrhythmogenicity of the marine biotoxin azaspiracid-2 in rats. Arch Toxicol 88, 425–434 (2014). https://doi.org/10.1007/s00204-013-1115-4
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DOI: https://doi.org/10.1007/s00204-013-1115-4