Experimental Basis for the High Oral Toxicity of Dinophysistoxin 1: A Comparative Study of DSP

Okadaic acid (OA) and its analogues, dinophysistoxin 1 (DTX1) and dinophysistoxin 2 (DTX2), are lipophilic and heat-stable marine toxins produced by dinoflagellates, which can accumulate in filter-feeding bivalves. These toxins cause diarrheic shellfish poisoning (DSP) in humans shortly after the in...

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Main Authors: Diego A. Fernández, M. Carmen Louzao, María Fraga, Natalia Vilariño, Mercedes R. Vieytes, Luis M. Botana
Format: Article
Language:English
Published: MDPI AG 2014-01-01
Series:Toxins
Subjects:
Online Access:http://www.mdpi.com/2072-6651/6/1/211
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author Diego A. Fernández
M. Carmen Louzao
María Fraga
Natalia Vilariño
Mercedes R. Vieytes
Luis M. Botana
author_facet Diego A. Fernández
M. Carmen Louzao
María Fraga
Natalia Vilariño
Mercedes R. Vieytes
Luis M. Botana
author_sort Diego A. Fernández
collection DOAJ
description Okadaic acid (OA) and its analogues, dinophysistoxin 1 (DTX1) and dinophysistoxin 2 (DTX2), are lipophilic and heat-stable marine toxins produced by dinoflagellates, which can accumulate in filter-feeding bivalves. These toxins cause diarrheic shellfish poisoning (DSP) in humans shortly after the ingestion of contaminated seafood. Studies carried out in mice indicated that DSP poisonous are toxic towards experimental animals with a lethal oral dose 2–10 times higher than the intraperitoneal (i.p.) lethal dose. The focus of this work was to study the absorption of OA, DTX1 and DTX2 through the human gut barrier using differentiated Caco-2 cells. Furthermore, we compared cytotoxicity parameters. Our data revealed that cellular viability was not compromised by toxin concentrations up to 1 μM for 72 h. Okadaic acid and DTX2 induced no significant damage; nevertheless, DTX1 was able to disrupt the integrity of Caco-2 monolayers at concentrations above 50 nM. In addition, confocal microscopy imaging confirmed that the tight-junction protein, occludin, was affected by DTX1. Permeability assays revealed that only DTX1 was able to significantly cross the intestinal epithelium at concentrations above 100 nM. These data suggest a higher oral toxicity of DTX1 compared to OA and DTX2.
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spelling doaj.art-33af61cb23014ff095f45fb1843515b42022-12-22T03:58:48ZengMDPI AGToxins2072-66512014-01-016121122810.3390/toxins6010211toxins6010211Experimental Basis for the High Oral Toxicity of Dinophysistoxin 1: A Comparative Study of DSPDiego A. Fernández0M. Carmen Louzao1María Fraga2Natalia Vilariño3Mercedes R. Vieytes4Luis M. Botana5Department of Pharmacology, Faculty of Veterinary, University of Santiago de Compostela, University Campus, Lugo 27002, SpainDepartment of Pharmacology, Faculty of Veterinary, University of Santiago de Compostela, University Campus, Lugo 27002, SpainDepartment of Pharmacology, Faculty of Veterinary, University of Santiago de Compostela, University Campus, Lugo 27002, SpainDepartment of Pharmacology, Faculty of Veterinary, University of Santiago de Compostela, University Campus, Lugo 27002, SpainDepartment of Physiology, Faculty of Veterinary, University of Santiago de Compostela, University Campus, Lugo 27002, SpainDepartment of Pharmacology, Faculty of Veterinary, University of Santiago de Compostela, University Campus, Lugo 27002, SpainOkadaic acid (OA) and its analogues, dinophysistoxin 1 (DTX1) and dinophysistoxin 2 (DTX2), are lipophilic and heat-stable marine toxins produced by dinoflagellates, which can accumulate in filter-feeding bivalves. These toxins cause diarrheic shellfish poisoning (DSP) in humans shortly after the ingestion of contaminated seafood. Studies carried out in mice indicated that DSP poisonous are toxic towards experimental animals with a lethal oral dose 2–10 times higher than the intraperitoneal (i.p.) lethal dose. The focus of this work was to study the absorption of OA, DTX1 and DTX2 through the human gut barrier using differentiated Caco-2 cells. Furthermore, we compared cytotoxicity parameters. Our data revealed that cellular viability was not compromised by toxin concentrations up to 1 μM for 72 h. Okadaic acid and DTX2 induced no significant damage; nevertheless, DTX1 was able to disrupt the integrity of Caco-2 monolayers at concentrations above 50 nM. In addition, confocal microscopy imaging confirmed that the tight-junction protein, occludin, was affected by DTX1. Permeability assays revealed that only DTX1 was able to significantly cross the intestinal epithelium at concentrations above 100 nM. These data suggest a higher oral toxicity of DTX1 compared to OA and DTX2.http://www.mdpi.com/2072-6651/6/1/211okadaic aciddinophysistoxin-1dinophysistoxin-2Caco-2intestinal permeabilitytrans-epithelial electric resistanceoccludinannexin VLumineximmunoassay
spellingShingle Diego A. Fernández
M. Carmen Louzao
María Fraga
Natalia Vilariño
Mercedes R. Vieytes
Luis M. Botana
Experimental Basis for the High Oral Toxicity of Dinophysistoxin 1: A Comparative Study of DSP
Toxins
okadaic acid
dinophysistoxin-1
dinophysistoxin-2
Caco-2
intestinal permeability
trans-epithelial electric resistance
occludin
annexin V
Luminex
immunoassay
title Experimental Basis for the High Oral Toxicity of Dinophysistoxin 1: A Comparative Study of DSP
title_full Experimental Basis for the High Oral Toxicity of Dinophysistoxin 1: A Comparative Study of DSP
title_fullStr Experimental Basis for the High Oral Toxicity of Dinophysistoxin 1: A Comparative Study of DSP
title_full_unstemmed Experimental Basis for the High Oral Toxicity of Dinophysistoxin 1: A Comparative Study of DSP
title_short Experimental Basis for the High Oral Toxicity of Dinophysistoxin 1: A Comparative Study of DSP
title_sort experimental basis for the high oral toxicity of dinophysistoxin 1 a comparative study of dsp
topic okadaic acid
dinophysistoxin-1
dinophysistoxin-2
Caco-2
intestinal permeability
trans-epithelial electric resistance
occludin
annexin V
Luminex
immunoassay
url http://www.mdpi.com/2072-6651/6/1/211
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