1
|
Loeffler CR, Bodi D, Tartaglione L, Dell'Aversano C, Preiss-Weigert A. Improving in vitro ciguatoxin and brevetoxin detection: selecting neuroblastoma (Neuro-2a) cells with lower sensitivity to ouabain and veratridine (OV-LS). HARMFUL ALGAE 2021; 103:101994. [PMID: 33980434 DOI: 10.1016/j.hal.2021.101994] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 12/31/2020] [Accepted: 01/25/2021] [Indexed: 06/12/2023]
Abstract
Marine biotoxins accumulating in seafood products pose a risk to human health. These toxins are often potent in minute amounts and contained within complex matrices; requiring sensitive, reliable, and robust methods for their detection. The mouse neuroblastoma (Neuro-2a) cytotoxicity assay (N2a-assay) is a sensitive, high-throughput, in vitro method effective for detecting sodium channel-specific marine biotoxins. The N2a-assay can be conducted to distinguish between specific effects on voltage-gated sodium (NaV) channels, caused by toxins that activate (e.g., ciguatoxins (CTXs), brevetoxins (PbTxs)) or block (e.g., tetrodotoxins, saxitoxins) the target NaV. The sensitivity and specificity of the assay to compounds activating the NaV are achieved through the addition of the pharmaceuticals ouabain (O) and veratridine (V). However, these compounds can be toxic to Neuro-2a cells and their application at insufficient or excessive concentrations can reduce the effectiveness of this assay for marine toxin detection. Therefore, during growth incubation, Neuro-2a cells were exposed to O and V, and surviving cells exhibiting a lower sensitivity to O and V (OV-LS) were propagated. OV-LS Neuro-2a cells were selected for 60-80% survival when exposed to 0.22/0.022 mM O/V during the cytotoxicity assay. At these conditions, OV-LS N2a cells demonstrated a 3.5-fold higher survival rate 71% ± 7.9 SD (n = 232), and lower sensitivity to O/V, compared to the original Neuro-2a cells 20% ± 9.0 SD (n = 16). Additionally, OV-LS N2a cells were 1.3-2.6-fold more sensitive for detecting CTX3C 1.35 pg/ml, CTX1B 2.06 pg/ml, and PbTx-3 3.04 ng/ml compared to Neuro-2a cells using 0.1/0.01 mM O/V. Detection of CTX3C in a complex fish matrix using OV-LS cells was 0.0048 pg CTX3C/mg fish tissue equivalent. This work shows the potential for a significant improvement in sensitivity for CTX3C, CTX1B, and PbTx-3 using the OV-LS N2a-assay.
Collapse
Affiliation(s)
- Christopher R Loeffler
- German Federal Institute for Risk Assessment, Department Safety in the Food Chain, National Reference Laboratory of Marine Biotoxins, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany - www.bfr.bund.de; Department of Pharmacy, School of Medicine and Surgery, University of Napoli Federico II, Via D. Montesano 49, 80131, Napoli, Italy.
| | - Dorina Bodi
- German Federal Institute for Risk Assessment, Department Safety in the Food Chain, National Reference Laboratory of Marine Biotoxins, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany - www.bfr.bund.de
| | - Luciana Tartaglione
- Department of Pharmacy, School of Medicine and Surgery, University of Napoli Federico II, Via D. Montesano 49, 80131, Napoli, Italy; CoNISMa - Italian Interuniversity Consortium on Marine Sciences, Piazzale Flaminio 9, 00196 Rome, Italy
| | - Carmela Dell'Aversano
- Department of Pharmacy, School of Medicine and Surgery, University of Napoli Federico II, Via D. Montesano 49, 80131, Napoli, Italy; CoNISMa - Italian Interuniversity Consortium on Marine Sciences, Piazzale Flaminio 9, 00196 Rome, Italy
| | - Angelika Preiss-Weigert
- German Federal Institute for Risk Assessment, Department Safety in the Food Chain, National Reference Laboratory of Marine Biotoxins, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany - www.bfr.bund.de
| |
Collapse
|
2
|
Neves RAF, Pardal MA, Nascimento SM, Silva A, Oliveira PJ, Rodrigues ET. High sensitivity of rat cardiomyoblast H9c2(2-1) cells to Gambierdiscus toxic compounds. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2020; 223:105475. [PMID: 32325308 DOI: 10.1016/j.aquatox.2020.105475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 03/18/2020] [Accepted: 03/18/2020] [Indexed: 06/11/2023]
Abstract
Ciguatera fish poisoning is a frequently reported non-bacterial food-borne illness related to the consumption of seafood contaminated with ciguatoxins, and possibly maitotoxins. These toxins are synthesized by marine dinoflagellate species of Gambierdiscus and Fukuyoa genera, and their abundance is a matter of great concern due to their adverse effects to aquatic life and human health. The present study aims to assess the sensitivity of rat cardiomyoblast H9c2(2-1) cells to Gambierdiscus toxic compounds using concentration- and time-dependent sulforhodamine B (SRB) colorimetric assays. Low concentrations of Gambierdiscus extracts (corresponding to 1.3-2.3 cells mL-1) induced a concentration-dependent response. Specificity in time-dependent response of H9c2(2-1) cells was demonstrated for G. excentricus after a 180 min exposure compared to both G. cf. belizeanus and G. silvae species, with EC50s obtained after 720 and 360 min, respectively. The sensitivity of H9c2(2-1) cells to dinoflagellate toxic compounds was also tested with other genera from benthic (Coolia malayensis, Ostreopsis cf. ovata, Prorocentrum hoffmannianum and P. lima) and planktonic (Amphidinium carterae and Lingulodinium polyedrum) habitats. Amphidinium, Coolia and Lingulodinium data did not present any concentration-response relationships, and EC50 values could only be obtained after 720 and 1440 min of exposure to both Prorocentrum species and O. cf. ovata, respectively. This study demonstrated that the H9c2(2-1) SRB assay represents a promising and sensitive tool for the detection of Gambierdiscus toxic compounds present in water samples, particularly of G. excentricus at very low cell abundances.
Collapse
Affiliation(s)
- Raquel A F Neves
- Department of Ecology and Marine Resources, Federal University of the State of Rio de Janeiro (UNIRIO), Av Pasteur 458-307, 22290-240, Rio de Janeiro, Brazil; CFE-Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal.
| | - Miguel A Pardal
- CFE-Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal.
| | - Silvia M Nascimento
- Department of Ecology and Marine Resources, Federal University of the State of Rio de Janeiro (UNIRIO), Av Pasteur 458-307, 22290-240, Rio de Janeiro, Brazil.
| | - Alexandra Silva
- Phytoplankton Laboratory, Division of Oceanography and Environment, Portuguese Institute for the Sea and Atmosphere (IPMA), Rua Alfredo Magalhães Ramalho 6, 1495-006, Lisboa, Portugal.
| | - Paulo J Oliveira
- CNC-Centre for Neuroscience and Cell Biology, University of Coimbra Biotech Building, Lot 8A, Biocant Park, 3060-197, Cantanhede, Portugal.
| | - Elsa T Rodrigues
- CFE-Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal.
| |
Collapse
|
3
|
Yau MS, Lei ENY, Ng IHM, Yuen CKK, Lam JCW, Lam MHW. Changes in the neurotransmitter profile in the central nervous system of marine medaka (Oryzias melastigma) after exposure to brevetoxin PbTx-1 - A multivariate approach to establish exposure biomarkers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 673:327-336. [PMID: 30991322 DOI: 10.1016/j.scitotenv.2019.03.193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/13/2019] [Accepted: 03/13/2019] [Indexed: 06/09/2023]
Abstract
A strategy to construct multivariate biomarkers for exposure to algal neurotoxins via correlating changes to the profiles of a series of neurotransmitters and their metabolites in the central nervous system (CNS) of exposed test organism is reported. 3-Month-old marine medaka (Oryzais melastigma) were exposed to waterborne brevetoxin PbTx-1 at two sub-lethal dose levels (0.5 and 2.5 μg-PbTx-1 L-1) for a duration of 12 h before quantification of 43 selected neurotransmitters and metabolites in their CNS were measured via dansyl chloride derivatization and LC-MS/MS determination. The profiling data were analyzed by multivariate statistical analyses, including principle component analysis (PCA), projection on latent structure-discriminate analysis (PLS-DA) and orthogonal projection on latent structure-discriminate analysis (OPLS-DA). Neurotransmitters and metabolites related to activation of voltage-gated sodium channels (VGSCs), N-methyl-D-aspartic acid receptors (NMDARs) and cholinergic neurotransmission were found to contribute significantly to class separation in the corresponding OPLS-DA models. Those models obtained from different exposure dosages were correlated by the Shared and Unique Structures Plot (SUS-plot) to identify appropriate variables for the construction of exposure biomarkers in the form of multivariate predictive scores. The established biomarkers for male and female medaka fish were able to predict acute sub-lethal exposure to PbTx-1 with good sensitivity and specificity (male fish: sensitivity 94.7%, specificity 80.0%; female fish: sensitivity 91.4%, specificity 83.3%). Neurotransmitter profiles in the CNS of medaka fish that should have recovered from exposure to PbTx-1 have also been determined to reveal long-term impacts to the CNS of the affected organism even after the exposure has been interrupted.
Collapse
Affiliation(s)
- Man-Shan Yau
- State Key Laboratory for Marine Pollution, City University of Hong Kong, Hong Kong, China; Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Elva Ngai-Yu Lei
- State Key Laboratory for Marine Pollution, City University of Hong Kong, Hong Kong, China; Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Isabel Hei-Ma Ng
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Carrie Ka-Ki Yuen
- State Key Laboratory for Marine Pollution, City University of Hong Kong, Hong Kong, China; Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - James Chung-Wah Lam
- State Key Laboratory for Marine Pollution, City University of Hong Kong, Hong Kong, China; Department of Science and Environmental Studies, Education University of Hong Kong, Hong Kong, China
| | - Michael Hon-Wah Lam
- State Key Laboratory for Marine Pollution, City University of Hong Kong, Hong Kong, China; Department of Chemistry, City University of Hong Kong, Hong Kong, China.
| |
Collapse
|
4
|
A Strategy to Replace the Mouse Bioassay for Detecting and Identifying Lipophilic Marine Biotoxins by Combining the Neuro-2a Bioassay and LC-MS/MS Analysis. Mar Drugs 2018; 16:md16120501. [PMID: 30545061 PMCID: PMC6315780 DOI: 10.3390/md16120501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 12/06/2018] [Accepted: 12/08/2018] [Indexed: 01/13/2023] Open
Abstract
Marine biotoxins in fish and shellfish can cause several symptoms in consumers, such as diarrhea, amnesia, or even death by paralysis. Monitoring programs are in place for testing shellfish on a regular basis. In some countries testing is performed using the so-called mouse bioassay, an assay that faces ethical concerns not only because of animal distress, but also because it lacks specificity and results in high amounts of false positives. In Europe, for lipophilic marine biotoxins (LMBs), a chemical analytical method using LC-MS/MS was developed as an alternative and is now the reference method. However, safety is often questioned when relying solely on such a method, and as a result, the mouse bioassay might still be used. In this study the use of a cell-based assay for screening, i.e., the neuro-2a assay, in combination with the official LC-MS/MS method was investigated as a new alternative strategy for the detection and quantification of LMBs. To this end, samples that had been tested previously with the mouse bioassay were analyzed in the neuro-2a bioassay and the LC-MS/MS method. The neuro-2a bioassay was able to detect all LMBs at the regulatory levels and all samples that tested positive in the mouse bioassay were also suspect in the neuro-2a bioassay. In most cases, these samples contained toxin levels (yessotoxins) that explain the outcome of the bioassay but did not exceed the established maximum permitted levels.
Collapse
|
5
|
Bodero M, Bovee TFH, Wang S, Hoogenboom RLAP, Klijnstra MD, Portier L, Hendriksen PJM, Gerssen A. Screening for the presence of lipophilic marine biotoxins in shellfish samples using the neuro-2a bioassay. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2017; 35:351-365. [PMID: 28884655 DOI: 10.1080/19440049.2017.1368720] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The neuro-2a bioassay is considered as one of the most promising cell-based in vitro bioassays for the broad screening of seafood products for the presence of marine biotoxins. The neuro-2a assay has been shown to detect a wide array of toxins like paralytic shellfish poisons (PSPs), ciguatoxins, and also lipophilic marine biotoxins (LMBs). However, the neuro-2a assay is rarely used for routine testing of samples due to matrix effects that, for example, lead to false positives when testing for LMBs. As a result there are only limited data on validation and evaluation of its performance on real samples. In the present study, the standard extraction procedure for LMBs was adjusted by introducing an additional clean-up step with n-hexane. Recovery losses due to this extra step were less than 10%. This wash step was a crucial addition in order to eliminate false-positive outcomes due to matrix effects. Next, the applicability of this assay was assessed by testing a broad range of shellfish samples contaminated with various LMBs, including diarrhetic shellfish toxins/poisons (DSPs). For comparison, the samples were also analysed by LC-MS/MS. Standards of all regulated LMBs were tested, including analogues of some of these toxins. The neuro-2a cells showed good sensitivity towards all compounds. Extracts of 87 samples, both blank and contaminated with various toxins, were tested. The neuro-2a outcomes were in line with those of LC-MS/MS analysis and support the applicability of this assay for the screening of samples for LMBs. However, for use in a daily routine setting, the test might be further improved and we discuss several recommended modifications which should be considered before a full validation is carried out.
Collapse
Affiliation(s)
- Marcia Bodero
- a BU Bioassays and Authenticity, RIKILT Wageningen University & Research , Wageningen , the Netherlands.,b Division of Toxicology , Wageningen University and Research , Wageningen , the Netherlands
| | - Toine F H Bovee
- a BU Bioassays and Authenticity, RIKILT Wageningen University & Research , Wageningen , the Netherlands
| | - Si Wang
- a BU Bioassays and Authenticity, RIKILT Wageningen University & Research , Wageningen , the Netherlands
| | - Ron L A P Hoogenboom
- a BU Bioassays and Authenticity, RIKILT Wageningen University & Research , Wageningen , the Netherlands
| | - Mirjam D Klijnstra
- a BU Bioassays and Authenticity, RIKILT Wageningen University & Research , Wageningen , the Netherlands
| | - Liza Portier
- a BU Bioassays and Authenticity, RIKILT Wageningen University & Research , Wageningen , the Netherlands
| | - Peter J M Hendriksen
- a BU Bioassays and Authenticity, RIKILT Wageningen University & Research , Wageningen , the Netherlands
| | - Arjen Gerssen
- a BU Bioassays and Authenticity, RIKILT Wageningen University & Research , Wageningen , the Netherlands
| |
Collapse
|
6
|
Reverté L, Soliño L, Carnicer O, Diogène J, Campàs M. Alternative methods for the detection of emerging marine toxins: biosensors, biochemical assays and cell-based assays. Mar Drugs 2014; 12:5719-63. [PMID: 25431968 PMCID: PMC4278199 DOI: 10.3390/md12125719] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/11/2014] [Accepted: 11/11/2014] [Indexed: 12/02/2022] Open
Abstract
The emergence of marine toxins in water and seafood may have a considerable impact on public health. Although the tendency in Europe is to consolidate, when possible, official reference methods based on instrumental analysis, the development of alternative or complementary methods providing functional or toxicological information may provide advantages in terms of risk identification, but also low cost, simplicity, ease of use and high-throughput analysis. This article gives an overview of the immunoassays, cell-based assays, receptor-binding assays and biosensors that have been developed for the screening and quantification of emerging marine toxins: palytoxins, ciguatoxins, cyclic imines and tetrodotoxins. Their advantages and limitations are discussed, as well as their possible integration in research and monitoring programs.
Collapse
Affiliation(s)
- Laia Reverté
- IRTA, Carretera Poble Nou km 5.5, 43540 Sant Carles de la Ràpita, Spain.
| | - Lucía Soliño
- IRTA, Carretera Poble Nou km 5.5, 43540 Sant Carles de la Ràpita, Spain.
| | - Olga Carnicer
- IRTA, Carretera Poble Nou km 5.5, 43540 Sant Carles de la Ràpita, Spain.
| | - Jorge Diogène
- IRTA, Carretera Poble Nou km 5.5, 43540 Sant Carles de la Ràpita, Spain.
| | - Mònica Campàs
- IRTA, Carretera Poble Nou km 5.5, 43540 Sant Carles de la Ràpita, Spain.
| |
Collapse
|
7
|
Sassolas A, Hayat A, Catanante G, Marty JL. Detection of the marine toxin okadaic acid: Assessing seafood safety. Talanta 2013; 105:306-16. [DOI: 10.1016/j.talanta.2012.10.049] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 10/10/2012] [Accepted: 10/13/2012] [Indexed: 10/27/2022]
|
8
|
Collaborative study for the detection of toxic compounds in shellfish extracts using cell-based assays. Part I: screening strategy and pre-validation study with lipophilic marine toxins. Anal Bioanal Chem 2012; 403:1983-93. [DOI: 10.1007/s00216-012-6028-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 03/30/2012] [Accepted: 04/06/2012] [Indexed: 10/28/2022]
|
9
|
Campàs M, Garibo D, Prieto-Simón B. Novel nanobiotechnological concepts in electrochemical biosensors for the analysis of toxins. Analyst 2012; 137:1055-67. [DOI: 10.1039/c2an15736e] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
10
|
Caillaud A, de la Iglesia P, Darius HT, Pauillac S, Aligizaki K, Fraga S, Chinain M, Diogène J. Update on methodologies available for ciguatoxin determination: perspectives to confront the onset of ciguatera fish poisoning in Europe. Mar Drugs 2010; 8:1838-907. [PMID: 20631873 PMCID: PMC2901828 DOI: 10.3390/md8061838] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 05/18/2010] [Accepted: 06/10/2010] [Indexed: 11/29/2022] Open
Abstract
Ciguatera fish poisoning (CFP) occurs mainly when humans ingest finfish contaminated with ciguatoxins (CTXs). The complexity and variability of such toxins have made it difficult to develop reliable methods to routinely monitor CFP with specificity and sensitivity. This review aims to describe the methodologies available for CTX detection, including those based on the toxicological, biochemical, chemical, and pharmaceutical properties of CTXs. Selecting any of these methodological approaches for routine monitoring of ciguatera may be dependent upon the applicability of the method. However, identifying a reference validation method for CTXs is a critical and urgent issue, and is dependent upon the availability of certified CTX standards and the coordinated action of laboratories. Reports of CFP cases in European hospitals have been described in several countries, and are mostly due to travel to CFP endemic areas. Additionally, the recent detection of the CTX-producing tropical genus Gambierdiscus in the eastern Atlantic Ocean of the northern hemisphere and in the Mediterranean Sea, as well as the confirmation of CFP in the Canary Islands and possibly in Madeira, constitute other reasons to study the onset of CFP in Europe [1]. The question of the possible contribution of climate change to the distribution of toxin-producing microalgae and ciguateric fish is raised. The impact of ciguatera onset on European Union (EU) policies will be discussed with respect to EU regulations on marine toxins in seafood. Critical analysis and availability of methodologies for CTX determination is required for a rapid response to suspected CFP cases and to conduct sound CFP risk analysis.
Collapse
Affiliation(s)
- Amandine Caillaud
- IRTA, Ctra. Poble Nou, Km 5,5. 43540 Sant Carles de la Ràpita, Spain; E-Mails: (A.C.); (P.I.)
| | - Pablo de la Iglesia
- IRTA, Ctra. Poble Nou, Km 5,5. 43540 Sant Carles de la Ràpita, Spain; E-Mails: (A.C.); (P.I.)
| | - H. Taiana Darius
- Laboratoire des micro-algues toxiques, Institut Louis Malardé, BP30, 98713 Papeete Tahiti, French Polynesia; E-Mails: (H.T.D.); (M.C.)
| | - Serge Pauillac
- Institut Pasteur, 25-28 rue du docteur Roux, 75 015 Paris, France; E-Mail: (S.P.)
| | - Katerina Aligizaki
- Department of Botany, School of Biology, Faculty of Sciences, Aristotle University, 54 124 Thessaloniki, Greece; E-Mail: (K.A.)
| | - Santiago Fraga
- Instituto Español de Oceanografía, Subida a Radio Faro, 50, 36390 Vigo, Spain; E-Mail: (S.F.)
| | - Mireille Chinain
- Laboratoire des micro-algues toxiques, Institut Louis Malardé, BP30, 98713 Papeete Tahiti, French Polynesia; E-Mails: (H.T.D.); (M.C.)
| | - Jorge Diogène
- IRTA, Ctra. Poble Nou, Km 5,5. 43540 Sant Carles de la Ràpita, Spain; E-Mails: (A.C.); (P.I.)
| |
Collapse
|
11
|
Campàs M, de la Iglesia P, Fernández-Tejedor M, Diogène J. Colorimetric and electrochemical phosphodiesterase inhibition assays for yessotoxin detection: development and comparison with LC-MS/MS. Anal Bioanal Chem 2010; 396:2321-30. [PMID: 20140666 DOI: 10.1007/s00216-009-3445-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 12/23/2009] [Accepted: 12/28/2009] [Indexed: 11/28/2022]
Abstract
This work describes the development and applicability of two functional assays for the detection of yessotoxin (YTX), a polycyclic ether marine toxin produced by dinoflagellates. The assays are based on the interaction between this toxin and the phosphodiesterase (PDE) enzyme and the subsequent measurement of the enzyme activity by colorimetric and electrochemical methods. Firstly, several enzyme substrates were tested in order to select those able to be detected by colorimetry or electrochemistry after enzymatic hydrolysis. The substrates that provided the highest absorbance values and density currents were p-nitrophenyl phenylphosphonate and alpha-naphthyl phosphate, respectively. After optimisation of the experimental parameters, limits of detection of 0.8 and 0.6 microM were attained by colorimetry and electrochemistry, respectively. An inhibitory effect of YTX on the PDE activity was observed. The assays have been applied to the analysis of YTX production by Protoceratium reticulatum cultures, and results were compared with liquid chromatography-tandem mass spectrometry analysis.
Collapse
Affiliation(s)
- Mònica Campàs
- IRTA, Ctra. Poble Nou, km. 5.5, 43540 Sant Carles de la Ràpita, Spain.
| | | | | | | |
Collapse
|
12
|
Cañete E, Campàs M, de la Iglesia P, Diogène J. NG108-15 cell-based and protein phosphatase inhibition assays as alternative semiquantitative tools for the screening of lipophilic toxins in mussels. Okadaic acid detection. Toxicol In Vitro 2009; 24:611-9. [PMID: 19850120 DOI: 10.1016/j.tiv.2009.10.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 10/13/2009] [Accepted: 10/14/2009] [Indexed: 12/01/2022]
Abstract
We report the application of a cell-based assay (CBA) using NG108-15 a hybridoma cell strain and a protein phosphatase inhibition-based assay (PPIA) as alternative toxicological or functional semiquantitative tools, respectively, for the screening of lipophilic toxins in mussels (Mytilusgalloprovincialis). Acetonic extracts were directly tested by CBA and PPIA but severe matrix effects were observed. As a solution, a simple 17-fraction protocol with solid-phase extraction (SPE) cartridges was optimised and applied as a previous step to the CBA or the PPIA. LC-MS/MS analyses were performed in parallel to determine the lipophilic toxins content in mussel extracts. Evaluation of the SPE protocol by LC-MS/MS showed okadaic acid (OA) recovery above 90% and negligible effects of mussel matrix on the SPE performance. The whole methods provided limits of detection of 47 and 45mug OA equivalents/kg for CBA and PPIA, respectively. The combined strategy permitted the identification of OA toxicity in two fractions, and allowed us to clearly distinguish between negative and positive samples, the latter being either OA-spiked or naturally-contaminated samples at levels equal or above the regulatory limit. The combination of fractioning with CBA or PPIA allows the quantification of the toxic and functional effects of samples above these concentrations.
Collapse
Affiliation(s)
- Elisabeth Cañete
- IRTA, Ctra. Poble Nou, km 5.5, 43540 Sant Carles de la Ràpita, Tarragona, Spain
| | | | | | | |
Collapse
|