scholarly journals Improved Isolation Procedures for Okadaic Acid Group Toxins from Shellfish (Mytilus edulis) and Microalgae (Prorocentrum lima)

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 647
Author(s):  
Jane Kilcoyne ◽  
Stephen Burrell ◽  
Cíara Nulty ◽  
Rafael Salas ◽  
Elliott J. Wright ◽  
...  
Keyword(s):  
Okadaic Acid ◽  
Certified Reference Materials ◽  
Toxin Production ◽  
Acid Group ◽  
Shellfish Poisoning ◽  
Prorocentrum Lima ◽  
Additional Stability ◽  
Maximum Cell ◽  
Cell Densities ◽  
Materials Used

Okadaic acid (OA) group toxins may accumulate in shellfish and can result in diarrhetic shellfish poisoning when consumed by humans, and are therefore regulated. Purified toxins are required for the production of certified reference materials used to accurately quantitate toxin levels in shellfish and water samples, and for other research purposes. An improved procedure was developed for the isolation of dinophysistoxin 2 (DTX2) from shellfish (M. edulis), reducing the number of purification steps from eight to five, thereby increasing recoveries to ~68%, compared to ~40% in a previously reported method, and a purity of >95%. Cell densities and toxin production were monitored in cultures of Prorocentrum lima, that produced OA, DTX1, and their esters, over ~1.5 years with maximum cell densities of ~70,000 cells mL−1 observed. Toxin accumulation progressively increased over the study period, to ~0.7 and 2.1 mg L−1 of OA and DTX1 (including their esters), respectively, providing information on appropriate harvesting times. A procedure for the purification of OA and DTX1 from the harvested biomass was developed employing four purification steps, with recoveries of ~76% and purities of >95% being achieved. Purities were confirmed by LC-HRMS, LC-UV, and NMR spectroscopy. Additional stability observations led to a better understanding of the chemistry of these toxins.

scholarly journals Risk Assessment of Pectenotoxins in New Zealand Bivalve Molluscan Shellfish, 2009–2019

Toxins ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 776
Author(s):  
Michael J. Boundy ◽  
D Tim Harwood ◽  
Andreas Kiermeier ◽  
Cath McLeod ◽  
Jeane Nicolas ◽  
...  
Keyword(s):  
New Zealand ◽  
Okadaic Acid ◽  
Acid Group ◽  
Fundamental Principle ◽  
Toxicity Data ◽  
Shellfish Poisoning ◽  
Oral Toxicity ◽  
Regulatory Policies ◽  
Safe Limit ◽  
The Impact

Pectenotoxins (PTXs) are produced by Dinophysis spp., along with okadaic acid, dinophysistoxin 1, and dinophysistoxin 2. The okadaic acid group toxins cause diarrhetic shellfish poisoning (DSP), so are therefore regulated. New Zealand currently includes pectenotoxins within the DSP regulations. To determine the impact of this decision, shellfish biotoxin data collected between 2009 and 2019 were examined. They showed that 85 samples exceeded the DSP regulatory limit (0.45%) and that excluding pectenotoxins would have reduced this by 10% to 76 samples. The incidence (1.3%) and maximum concentrations of pectenotoxins (0.079 mg/kg) were also found to be low, well below the current European Food Safety Authority (EFSA) safe limit of 0.12 mg/kg. Inclusion within the DSP regulations is scientifically flawed, as pectenotoxins and okadaic acid have a different mechanism of action, meaning that their toxicities are not additive, which is the fundamental principle of grouping toxins. Furthermore, evaluation of the available toxicity data suggests that pectenotoxins have very low oral toxicity, with recent studies showing no oral toxicity in mice dosed with the PTX analogue PTX2 at 5000 µg/kg. No known human illnesses have been reported due to exposure to pectenotoxins in shellfish, a fact which combined with the toxicity data indicates that they pose negligible risk to humans. Regulatory policies should be commensurate with the level of risk, thus deregulation of PTXs ought to be considered, a stance already adopted by some countries.

scholarly journals A Biomass Upscale System for the Marine Dinoflagellate Prorocentrum lima and the Production of Bioactive Lipophilic Toxins

2017 ◽  
Vol 5 (4) ◽  
pp. 479-485 ◽  
Author(s):  
Ioanna Varkitzi ◽  
Kalliopi Pagou ◽  
Christina Pyrgaki ◽  
Ioannis Hatzianestis
Keyword(s):  
Large Scale ◽  
Toxin Production ◽  
Shellfish Poisoning ◽  
Culture Volume ◽  
Prorocentrum Lima ◽  
Marine Dinoflagellate ◽  
Mass Cultures ◽  
Diarrheic Shellfish Poisoning ◽  
Marine Dinoflagellates ◽  
Lipophilic Toxins

Biotechnological applications of toxic marine dinoflagellates include seafood safety and biomedical, pharmaceutical and research purposes of their toxins among other bioproducts and bioactive compounds that they produce. The supply of sufficient quantities of phycotoxins for investigational uses remains in demand. Some of these toxins, available in small amounts, are quite expensive while their chemical synthesis is complex and costly. However, some quantities of these toxins could be produced with mass cultures of the appropriate dinoflagellates, which are however difficult to handle. Prorocentrum lima is a cosmopolitan marine dinoflagellate, which synthesizes toxins that cause a diarrheic syndrome to humans through the consumption of contaminated shellfish and fish (Diarrheic Shellfish Poisoning, DSP). The aim of this study was to design and develop a biomass upscale system for the production of the lipophilic toxins okadaic acid (OA) and dinophysistoxin 1 (DTX1) from the produced biomass of Prorocentrum lima. In our study, P. lima was grown in large scale semi-continuous cultures under controlled laboratory conditions. The maximum biomass produced was 20690 cells/mL. Maximum toxin production was 63.66 ng/mL for OA and 8.07 ng/mL for DTX1. Toxin quota in P. lima cells was 88.7% OA and 11.3% DTX1. The produced culture volume was 300 L and the total volume capacity of the upscale system could reach 500 L.Int. J. Appl. Sci. Biotechnol. Vol 5(4): 479-485

scholarly journals Toxins of Okadaic Acid-Group Increase Malignant Properties in Cells of Colon Cancer

Toxins ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 179 ◽  
Author(s):  
Danae Jiménez-Cárcamo ◽  
Carlos García ◽  
Héctor R. Contreras
Keyword(s):  
Colon Cancer ◽  
Cell Death ◽  
Cell Line ◽  
Cell Lines ◽  
Okadaic Acid ◽  
Protein Phosphatase ◽  
Acid Group ◽  
Shellfish Poisoning ◽  
Aggressive Phenotype ◽  
Tumoral Cell

Diarrhetic shellfish poisoning (DSP) is a syndrome caused by the intake of shellfish contaminated with a group of lipophilic and thermostable toxins, which consists of okadaic acid (OA), dinophysistoxin-1 (DTX-1) and dinophysistoxin-2 (DTX-2). These toxins are potent protein Ser/Thr phosphatase inhibitors, mainly type 1 protein phosphatase (PP1) and type 2A protein phosphatase (PP2A). Different effects have been reported at the cellular, molecular and genetic levels. In this study, changes in cell survival and cell mobility induced by OA, DTX-1 and DTX-2 were determined in epithelial cell lines of the colon and colon cancer. The cell viability results showed that tumoral cell lines were more resistant to toxins than the nontumoral cell line. The results of the functional assays for testing cell migration, evaluation of cell death and the expression of proteins associated with cell adhesion showed a dual effect of toxins since in the nontumoral cell line, a greater induction of cell death, presumably by anoikis, was detected. In the tumoral cell lines, there was an induction of a more aggressive phenotype characterized by increased resistance to toxins, increased migration and increased FAK activation. In tumoral cell lines of colon cancer, OA, DTX-1/DTX-2 induce a more aggressive phenotype.

scholarly journals Effects of the Marine Biotoxins Okadaic Acid and Dinophysistoxins on Fish

2021 ◽  
Vol 9 (3) ◽  
pp. 293
Author(s):  
Mauro Corriere ◽  
Lucía Soliño ◽  
Pedro Reis Costa
Keyword(s):  
Okadaic Acid ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Current Knowledge ◽  
Global Climate ◽  
Scientific Evidence ◽  
Shellfish Poisoning ◽  
Morphological Alterations ◽  
The Impact ◽  
Dsp Toxins

Natural high proliferations of toxin-producing microorganisms in marine and freshwater environments result in dreadful consequences at the socioeconomically and environmental level due to water and seafood contamination. Monitoring programs and scientific evidence point to harmful algal blooms (HABs) increasing in frequency and intensity as a result of global climate alterations. Among marine toxins, the okadaic acid (OA) and the related dinophysistoxins (DTX) are the most frequently reported in EU waters, mainly in shellfish species. These toxins are responsible for human syndrome diarrhetic shellfish poisoning (DSP). Fish, like other marine species, are also exposed to HABs and their toxins. However, reduced attention has been given to exposure, accumulation, and effects on fish of DSP toxins, such as OA. The present review intends to summarize the current knowledge of the impact of DSP toxins and to identify the main issues needing further research. From data reviewed in this work, it is clear that exposure of fish to DSP toxins causes a range of negative effects, from behavioral and morphological alterations to death. However, there is still much to be investigated about the ecological and food safety risks related to contamination of fish with DSP toxins.

Development of Certified Reference Materials for Diarrhetic Shellfish Poisoning Toxins, Part 2: Shellfish Matrix Materials

2016 ◽  
Vol 99 (5) ◽  
pp. 1163-1172 ◽  
Author(s):  
Pearse McCarron ◽  
Kelley L Reeves ◽  
Sabrina D Giddings ◽  
Daniel G Beach ◽  
Michael A Quilliam
Keyword(s):  
Reference Materials ◽  
Matrix Effects ◽  
Certified Reference Materials ◽  
Standard Addition ◽  
Tissue Homogenate ◽  
Shellfish Poisoning ◽  
Diarrhetic Shellfish Poisoning ◽  
Preliminary Work ◽  
Seafood Industry ◽  
Human Illness

Abstract Okadaic acid (OA) and its analogs, dinophysistoxins-1 (DTX1) and -2 (DTX2) are lipophilic biotoxins produced by marine algae that can accumulate in shellfish and cause the human illness known as diarrhetic shellfish poisoning (DSP). Regulatory testing of shellfish is required to protect consumers and the seafood industry. Certified reference materials (CRMs) are essential for the development, validation, and quality control of analytical methods, and thus play an important role in toxin monitoring. This paper summarizes work on research and development of shellfish tissue reference materials for OA and DTXs. Preliminary work established the appropriate conditions for production of shellfish tissue CRMs for OA and DTXs. Source materials, including naturally incurred shellfish tissue and cultured algae, were screened for their DSP toxins. This preliminary work informed planning and production of a wet mussel (Mytilus edulis) tissue homogenate matrix CRM. The homogeneity and stability of the CRM were evaluated and found to be fit-for-purpose. Extraction and LC-tandem MS methods were developed to accurately certify the concentrations of OA, DTX1, and DTX2 using a combination of standard addition and matrix-matched calibration to compensate for matrix effects in electrospray ionization. The concentration of domoic acid was also certified. Uncertainties were assigned following standards and guidelines from the International Organization for Standardization. The presence of other toxins in the CRM was also assessed and information values are reported for OA and DTX acyl esters.

scholarly journals First Report of Okadaic Acid and Pectenotoxins in Individual Cells of Dinophysis and in Scallops Argopecten purpuratus from Perú

Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 490 ◽  
Author(s):  
Alex Alcántara-Rubira ◽  
Víctor Bárcena-Martínez ◽  
Maribel Reyes-Paulino ◽  
Katherine Medina-Acaro ◽  
Lilibeth Valiente-Terrones ◽  
...  
Keyword(s):  
Okadaic Acid ◽  
Harmful Algal Bloom ◽  
Shellfish Poisoning ◽  
The South ◽  
First Report ◽  
The North ◽  
Cell Quota ◽  
Regulatory Limits ◽  
Argopecten Purpuratus ◽  
Production Areas

Causative species of Harmful Algal Bloom (HAB) and toxins in commercially exploited molluscan shellfish species are monitored weekly from four classified shellfish production areas in Perú (three in the north and one in the south). Okadaic acid (OA) and pectenotoxins (PTXs) were detected in hand-picked cells of Dinophysis (D. acuminata-complex and D. caudata) and in scallops (Argopecten purpuratus), the most important commercial bivalve species in Perú. LC-MS analyses revealed two different toxin profiles associated with species of the D. acuminata-complex: (a) one with OA (0.3–8.0 pg cell−1) and PTX2 (1.5–11.1 pg cell−1) and (b) another with only PTX2 which included populations with different toxin cell quota (9.3–9.6 pg cell−1 and 5.8–9.2 pg cell−1). Toxin results suggest the likely presence of two morphotypes of the D. acuminata-complex in the north, and only one of them in the south. Likewise, shellfish toxin analyses revealed the presence of PTX2 in all samples (10.3–34.8 µg kg−1), but OA (7.7–15.2 µg kg−1) only in the northern samples. Toxin levels were below the regulatory limits established for diarrhetic shellfish poisoning (DSP) and PTXs (160 µg OA kg−1) in Perú, in all samples analyzed. This is the first report confirming the presence of OA and PTX in Dinophysis cells and in shellfish from Peruvian coastal waters.

scholarly journals Influence of seasonality on the presence of okadaic acid associated with Dinophysis species: A four-year study in Sardinia (Italy)

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Alessandro G. Mudadu ◽  
Anna Maria Bazzoni ◽  
Riccardo Bazzardi ◽  
Giuseppa Lorenzoni ◽  
Barbara Soro ◽  
...  
Keyword(s):  
Okadaic Acid ◽  
Economic Loss ◽  
Abundant Species ◽  
Study Data ◽  
Shellfish Poisoning ◽  
Bivalve Molluscs ◽  
Toxic Algae ◽  
Different Seasons ◽  
Lipophilic Toxins ◽  
Production Areas

In Sardinia (Italy), bivalve molluscs production plays an important role in the trade balance. Diarrhoetic shellfish poisoning (DSP), an intoxication caused by the ingestion of bivalve molluscs that have accumulated high levels of Okadaic acid (OA), may represent a serious risk for the public health and a remarkable economic loss for the producers. Aim of this work was to improve knowledge about the repeatability of OA accumulation phenomena in various seasons trying to understand whether or not there was a trend. Also, the interaction between toxic algae and OA accumulation was examined. In this study, data of lipophilic toxins, water temperature and abundance of DSP-producing microalgal species were collected in a four-year period (2015–2018) in coastal production areas of Sardinia. Several episodes of OA positive values (>160 eq μgAO/Kg pe, Reg 853/04) were recorded during the study period in different production areas of Sardinia and in different seasons. A seasonal repeatability of OA accumulation in molluscs was observed in some production areas; moreover, different temporal gaps between the presence of toxic algae and OA accumulation were reported. Toxicity was observed almost exclusively in Mytilus galloprovincialis Lamark (99%), being this matrix the most abundant species bred in Sardinia.

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