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Vlasenko AE, Pereverzeva AO, Velansky PV, Magarlamov TY. Tetrodotoxins in Tissues and Cells of Different Body Regions of Ribbon Worms Kulikovia alborostrata and K. manchenkoi from Spokoynaya Bay, Sea of Japan. Toxins (Basel) 2024; 16:186. [PMID: 38668611 PMCID: PMC11053740 DOI: 10.3390/toxins16040186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/26/2024] [Accepted: 04/04/2024] [Indexed: 04/29/2024] Open
Abstract
Nemerteans, or ribbon worms, possess tetrodotoxin and its analogues (TTXs), neurotoxins of bacterial origin, which they presumably use for capturing prey and self-defense. Most TTXs-containing nemertean species have low levels of these toxins and, therefore, have usually been neglected in studies of TTXs functions and accumulation. In the present study, Kulikovia alborostrata and K. manchenkoi, two closely related species, were analyzed for TTXs distribution in the body using the HPLC-MS/MS and fluorescence microscopy methods. The abundance of TTXs-positive cells was determined in the proboscis, integument, and digestive system epithelium. As a result, six TTXs-positive cell types were identified in each species; however, only four were common. Moreover, the proportions of the toxins in different body parts were estimated. According to the HPLC-MS/MS analysis, the TTXs concentrations in K. alborostrata varied from 0.91 ng/g in the proboscis to 5.52 ng/g in the precerebral region; in K. manchenkoi, the concentrations ranged from 7.47 ng/g in the proboscis to 72.32 ng/g in the posterior body region. The differences observed between the two nemerteans in the distribution of the TTXs were consistent with the differences in the localization of TTXs-positive cells. In addition, TTXs-positive glandular cell types were found in the intestine and characterized for the first time. TTXs in the new cell types were assumed to play a unique physiological role for nemerteans.
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Affiliation(s)
| | | | | | - Timur Yu. Magarlamov
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, 690041 Vladivostok, Russia
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Miyazaki K, Suo R, Itoi S, Hirota J, Adachi M, Miyasaka T, Nishikawa T, Yokoyama T, Sato S, Takada K. 5, 6, 11-trideoxy tetrodotoxin attracts tiger puffer Takifugu rubripes. Toxicon 2024; 237:107539. [PMID: 38042308 DOI: 10.1016/j.toxicon.2023.107539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/23/2023] [Accepted: 11/23/2023] [Indexed: 12/04/2023]
Abstract
Tetrodotoxin (TTX) is a potent neurotoxin that binds to voltage-gated sodium channels and blocks the passage of sodium ions. TTX is widely distributed in both terrestrial and marine organisms, and the toxic puffers are believed to accumulate TTX through the food chain. Although pufferfish was previously thought to be attracted by TTX, recent finding from electroolfactogram (EOG) studies have indicated that the olfactory epithelium of T. alboplumbeus responded to 5, 6, 11-trideoxyTTX (TDT), but not to TTX itself. In this study, we examined behavioral experiments for Takifugu rubripes to distinguish between TTX and TDT under static and flow-through conditions. Our data clearly suggested that T. rubripes juveniles were attracted to TDT, not TTX. Moreover, we determined that the minimum effective dose of TDT to attract the puffer was 1-2 nmol of TDT under static conditions and 50-60 nmol of TDT under flow-through conditions. Following the experiments under static conditions, numerous bite marks by the pufferfish were found solely on the agarose gel infused with TDT. Based on these finding, we hypothesize that the pufferfish are attracted to TDT derived from prey, leading them effectively become toxic.
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Affiliation(s)
- Kairi Miyazaki
- School of Marine Biosciences, Kitasato University, Japan
| | - Rei Suo
- College of Bioresource Sciences, Nihon University, Japan
| | - Shiro Itoi
- College of Bioresource Sciences, Nihon University, Japan
| | - Junji Hirota
- Graduate School of Life Science and Technology, Tokyo Institute of Technology, Japan
| | - Masaatsu Adachi
- Graduate School of Pharmaceutical Sciences, Tohoku University, Japan
| | | | - Toshio Nishikawa
- Graduate School of Bioagricultural Sciences, Nagoya University, Japan
| | | | - Shigeru Sato
- School of Marine Biosciences, Kitasato University, Japan
| | - Kentaro Takada
- School of Marine Biosciences, Kitasato University, Japan.
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Kosker AR, Karakus M, Katikou P, Dal İ, Durmus M, Ucar Y, Ayas D, Özogul F. Monthly Variation of Tetrodotoxin Levels in Pufferfish ( Lagocephalus sceleratus) Caught from Antalya Bay, Mediterranean Sea. Mar Drugs 2023; 21:527. [PMID: 37888462 PMCID: PMC10608123 DOI: 10.3390/md21100527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/02/2023] [Accepted: 10/03/2023] [Indexed: 10/28/2023] Open
Abstract
The silver-cheeked toadfish (Lagocephalus sceleratus), an invasive alien pufferfish species that has rapidly settled throughout the Mediterranean region, poses significant threats not only to native marine species and fisheries but also to public health due to the tetrodotoxin (TTX) they harbor. In this study, TTX concentrations in L. sceleratus from Antalya Bay in the Northeastern Mediterranean Sea were investigated using Q-TOF-LC-MS on a monthly basis over a one-year period. Pufferfish were caught by angling from May 2018 to April 2019. The TTX levels in three different tissues (gonads, liver, and muscle) of 110 pufferfish in total were determined in both male and female individuals caught for 11 months. The highest TTX mean levels generally occurred in the gonads and the lowest in the muscle samples. As regards the maximum TTX contents, the highest concentrations determined were 68.2, 34.2, and 7.8 µg/g in the gonad, liver, and muscle tissues, respectively. The highest levels were generally observed in late autumn to winter (especially in November and December) in all tissues from both genders. Female individuals were generally found to be more toxic than male individuals. The TTX levels found confirm that the consumption of L. sceleratus from Antalya Bay remains dangerous throughout the year, and thus L. sceleratus constantly constitutes an important risk source for public health.
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Affiliation(s)
- Ali Rıza Kosker
- Department of Seafood Processing Technology, Faculty of Fisheries, Cukurova University, 01330 Adana, Turkey; (M.D.); (F.Ö.)
| | - Merve Karakus
- Mediterranean Fisheries Research Production and Training Institute, Demre Unit, 07570 Antalya, Turkey; (M.K.); (İ.D.)
| | - Panagiota Katikou
- Veterinary Research Institute of Thessaloniki, Hellenic Agricultural Organization—DIMITRA, Ktima Thermis, 57001 Thessaloniki, Greece
| | - İsmail Dal
- Mediterranean Fisheries Research Production and Training Institute, Demre Unit, 07570 Antalya, Turkey; (M.K.); (İ.D.)
| | - Mustafa Durmus
- Department of Seafood Processing Technology, Faculty of Fisheries, Cukurova University, 01330 Adana, Turkey; (M.D.); (F.Ö.)
| | - Yılmaz Ucar
- Vocational School of Aladag, Department of Forestry, Cukurova University, 01720 Adana, Turkey;
| | - Deniz Ayas
- Fisheries Faculty, Mersin University, 33169 Mersin, Turkey;
| | - Fatih Özogul
- Department of Seafood Processing Technology, Faculty of Fisheries, Cukurova University, 01330 Adana, Turkey; (M.D.); (F.Ö.)
- Biotechnology Research and Application Center, Cukurova University, 01330 Adana, Turkey
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Antonelli P, Peruzzo A, Mancin M, Boscolo Anzoletti A, Dall'Ara S, Orsini M, Bordin P, Arcangeli G, Zanolin B, Barco L, Losasso C. Tetrodotoxin in bivalve mollusks: An integrated study towards the comprehension of the influencing factors of a newly native phenomenon. Chemosphere 2023; 339:139682. [PMID: 37527741 DOI: 10.1016/j.chemosphere.2023.139682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/24/2023] [Accepted: 07/28/2023] [Indexed: 08/03/2023]
Abstract
Tetrodotoxins (TTXs) are potent neurotoxins named after the Tetraodontidae fish family. The ingestion of TTX-contaminated flesh can cause neurotoxic symptoms and can lead to death. In 2017 symptoms the European Food Safety Authority (EFSA) recognized the threat to food safety resulting from TTX exposure via food consumption and, thus, proposed a safety limit of 44 μg/kg of TTX in marine gastropods and bivalves. To date, however, TTXs have not yet been included in the list of biotoxins to be monitored within the European Union, even though, in a few cases, levels of TTX found were higher than the EFSA limit. The origin of TTX production is debated and the roles of both biotic and abiotic factors on TTX-mediated toxic events remain unclear. In order to meet these knowledge requests the present study was aimed to investigate the role of seawater temperature, pH, water conductivity, and oxygen saturation, along with the marine phytoplankton community and the bacterial community of mussels and oysters on the accumulation of TTX and analogues in the bivalves. Abiotic parameters were measured by means of a multi-parametric probe, phytoplankton community was analyzed by optic microscopy while microbial community was described by amplicon metataxonomic sequencing, TTXs concentration in the collected matrices were measured by HILIC-MS/MS. A possible role of seawater pH and temperature, among the investigated abiotic factors, in regulating the occurrence of TTXs was found. Regarding biotic variables, a possible influence of Vibrio, Shewanella and Flavobacteriaceae in the occurrence of TTXs was found. Concurrently, Prorocentrum cordatum cell numbers were correlated to the incidence of TTX in mussels. The results herein collected suggest that environmental variables play a consistent part in the occurrence of TTX in the edible bivalve habitats, and there are also indications of a potential role played by specific bacteria taxa in association with phytoplankton.
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Affiliation(s)
- Pietro Antonelli
- Microbial Ecology and Microorganisms Genomics Laboratory, Istituto Zooprofilattico Sperimentale Delle Venezie, PD, Viale Dell'Università 10, 35020, Legnaro, Italy
| | - Arianna Peruzzo
- Microbial Ecology and Microorganisms Genomics Laboratory, Istituto Zooprofilattico Sperimentale Delle Venezie, PD, Viale Dell'Università 10, 35020, Legnaro, Italy
| | - Marzia Mancin
- Microbial Ecology and Microorganisms Genomics Laboratory, Istituto Zooprofilattico Sperimentale Delle Venezie, PD, Viale Dell'Università 10, 35020, Legnaro, Italy
| | - Aurora Boscolo Anzoletti
- Microbial Ecology and Microorganisms Genomics Laboratory, Istituto Zooprofilattico Sperimentale Delle Venezie, PD, Viale Dell'Università 10, 35020, Legnaro, Italy
| | - Sonia Dall'Ara
- National Reference Laboratory for Marine Biotoxins, Fondazione Centro Ricerche Marine, Viale A. Vespucci 2, 47042, Cesenatico, FC, Italy
| | - Massimiliano Orsini
- Microbial Ecology and Microorganisms Genomics Laboratory, Istituto Zooprofilattico Sperimentale Delle Venezie, PD, Viale Dell'Università 10, 35020, Legnaro, Italy
| | - Paola Bordin
- Microbial Ecology and Microorganisms Genomics Laboratory, Istituto Zooprofilattico Sperimentale Delle Venezie, PD, Viale Dell'Università 10, 35020, Legnaro, Italy
| | - Giuseppe Arcangeli
- Specialistic Aquatic Animal Health Centre, Istituto Zooprofilattico Sperimentale Delle Venezie, PD, Viale Dell'Università 10, 35020, Legnaro, Italy
| | - Bruno Zanolin
- Regional Environmental Protection Agency of Friuli Venezia Giulia, ARPA FVG, Via Cairoli 14, 33057, Palmanova, UD, Italy
| | - Lisa Barco
- Microbial Ecology and Microorganisms Genomics Laboratory, Istituto Zooprofilattico Sperimentale Delle Venezie, PD, Viale Dell'Università 10, 35020, Legnaro, Italy
| | - Carmen Losasso
- Microbial Ecology and Microorganisms Genomics Laboratory, Istituto Zooprofilattico Sperimentale Delle Venezie, PD, Viale Dell'Università 10, 35020, Legnaro, Italy.
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Bucciarelli GM, Smith SJ, Choe JJ, Shin PD, Fisher RN, Kats LB. Native amphibian toxin reduces invasive crayfish feeding with potential benefits to stream biodiversity. BMC Ecol Evol 2023; 23:51. [PMID: 37700256 PMCID: PMC10498594 DOI: 10.1186/s12862-023-02162-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 08/24/2023] [Indexed: 09/14/2023] Open
Abstract
BACKGROUND Biodiversity is generally reduced when non-native species invade an ecosystem. Invasive crayfish, Procambarus clarkii, populate California freshwater streams, and in the Santa Monica Mountains (Los Angeles, USA), their introduction has led to trophic cascades due to omnivorous feeding behavior and a rapid rate of population growth. The native California newt, Taricha torosa, possesses a neurotoxin, tetrodotoxin (TTX), that affects freshwater animal behavior. Given P. clarkii has a limited evolutionary history with TTX, we hypothesized that TTX may affect crayfish feeding behaviors. To determine if TTX affects P. clarkii behavior, we measured cumulative movement and various feeding behaviors of P. clarkii exposed to (i) waterborne, ecologically realistic concentrations of TTX (~ 3.0 × 10- 8 moles/L), (ii) an anuran chemical cue to account for intraguild cues, or (iii) a T. torosa chemical cue with quantitated TTX in it (~ 6.2 × 10- 8 moles/L). RESULTS We found that the presence of TTX in any form significantly reduced crayfish movement and decreased the amount of food consumed over time. Crayfish responses to the anuran treatment did not significantly differ from controls. CONCLUSION Our laboratory results show that naturally occurring neurotoxin from native California newts limits invasive crayfish foraging and feeding rates, which may play a role in preserving local stream ecosystems by limiting invasive crayfish behaviors that are detrimental to biodiversity.
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Affiliation(s)
- Gary M Bucciarelli
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
- Department of Wildlife, Fish, and Conservation Science, University of California, Davis, Davis, CA, 95616, USA.
| | - Sierra J Smith
- Natural Science Division, Pepperdine University, Malibu, CA, 90263, USA
| | - Justin J Choe
- Natural Science Division, Pepperdine University, Malibu, CA, 90263, USA
| | - Phoebe D Shin
- Natural Science Division, Pepperdine University, Malibu, CA, 90263, USA
| | - Robert N Fisher
- Western Ecological Research Center, U.S. Geological Survey, San Diego, CA, 92101, USA
| | - Lee B Kats
- Natural Science Division, Pepperdine University, Malibu, CA, 90263, USA
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Thompson JN. The ripple effects of clines from coevolutionary hotspots to coldspots. Mol Ecol 2023; 32:4461-4463. [PMID: 37296535 DOI: 10.1111/mec.17042] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/22/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023]
Abstract
Coevolution has the potential to alter not only the ecological interactions of coevolving partners, but also their interactions with yet other species. The effects of coevolution may ripple throughout networks of interacting species, cascading across trophic levels, swamping competitors, or facilitating survival or reproduction of yet other species linked only indirectly to the coevolving partners. These ripple effects of coevolution may differ among communities, amplifying how the coevolutionary process produces geographic mosaics of traits and outcomes in interactions among species. In a From the Cover article in this issue of Molecular Ecology, Hague et al. (2022) provide a clear example, using the well-studied interactions between Pacific newts (Taricha spp.) and their common garter snake (Thamnophis sirtalis) predators in western North America. Pacific newts harbour tetrodotoxin (TTX), which is highly toxic to vertebrate predators. In coevolutionary hotspots, extreme escalation of toxicity in the newts and resistance to toxicity in the snakes have resulted in snake populations that retain high levels of TTX. In two geographic regions, snakes in these hotspot populations have evolved bright, aposematic colours that may act as warning signals to their own vertebrate predators. The warning signals and toxin-resistance alleles in the snake populations decrease clinally away from the coevolutionary hotpots, shaped by a geographically variable mix of selection imposed by the snakes' prey and by their own predators.
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Affiliation(s)
- John N Thompson
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, California, USA
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Hague MTJ, Miller LE, Stokes AN, Feldman CR, Brodie ED, Brodie ED. Conspicuous coloration of toxin-resistant predators implicates additional trophic interactions in a predator-prey arms race. Mol Ecol 2023; 32:4482-4496. [PMID: 36336815 DOI: 10.1111/mec.16772] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/21/2022] [Accepted: 11/03/2022] [Indexed: 08/08/2023]
Abstract
Antagonistic coevolution between natural enemies can produce highly exaggerated traits, such as prey toxins and predator resistance. This reciprocal process of adaptation and counter-adaptation may also open doors to other evolutionary novelties not directly involved in the phenotypic interface of coevolution. We tested the hypothesis that predator-prey coevolution coincided with the evolution of conspicuous coloration on resistant predators that retain prey toxins. In western North America, common garter snakes (Thamnophis sirtalis) have evolved extreme resistance to tetrodotoxin (TTX) in the coevolutionary arms race with their deadly prey, Pacific newts (Taricha spp.). TTX-resistant snakes can retain large amounts of ingested TTX, which could serve as a deterrent against the snakes' own predators if TTX toxicity and resistance are coupled with a conspicuous warning signal. We evaluated whether arms race escalation covaries with bright red coloration in snake populations across the geographic mosaic of coevolution. Snake colour variation departs from the neutral expectations of population genetic structure and covaries with escalating clines of newt TTX and snake resistance at two coevolutionary hotspots. In the Pacific Northwest, bright red coloration fits an expected pattern of an aposematic warning to avian predators: TTX-resistant snakes that consume highly toxic newts also have relatively large, reddish-orange dorsal blotches. Snake coloration also seems to have evolved with the arms race in California, but overall patterns are less intuitively consistent with aposematism. These results suggest that interactions with additional trophic levels can generate novel traits as a cascading consequence of arms race coevolution across the geographic mosaic.
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Affiliation(s)
- Michael T J Hague
- Division of Biological Sciences, University of Montana, Missoula, Montana, USA
| | - Lauren E Miller
- Department of Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Amber N Stokes
- Department of Biology, California State University, Bakersfield, California, USA
| | - Chris R Feldman
- Department of Biology, University of Nevada, Reno, Nevada, USA
| | - Edmund D Brodie
- Department of Biology, Utah State University, Logan, Utah, USA
| | - Edmund D Brodie
- Department of Biology, University of Virginia, Charlottesville, Virginia, USA
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Alkassar M, Sanchez-Henao A, Reverté J, Barreiro L, Rambla-Alegre M, Leonardo S, Mandalakis M, Peristeraki P, Diogène J, Campàs M. Evaluation of Toxicity Equivalency Factors of Tetrodotoxin Analogues with a Neuro-2a Cell-Based Assay and Application to Puffer Fish from Greece. Mar Drugs 2023; 21:432. [PMID: 37623713 PMCID: PMC10455759 DOI: 10.3390/md21080432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 07/27/2023] [Accepted: 07/29/2023] [Indexed: 08/26/2023] Open
Abstract
Tetrodotoxin (TTX) is a potent marine neurotoxin involved in poisoning cases, especially through the consumption of puffer fish. Knowledge of the toxicity equivalency factors (TEFs) of TTX analogues is crucial in monitoring programs to estimate the toxicity of samples analyzed with instrumental analysis methods. In this work, TTX analogues were isolated from the liver of a Lagocephalus sceleratus individual caught on South Crete coasts. A cell-based assay (CBA) for TTXs was optimized and applied to the establishment of the TEFs of 5,11-dideoxyTTX, 11-norTTX-6(S)-ol, 11-deoxyTTX and 5,6,11-trideoxyTTX. Results showed that all TTX analogues were less toxic than the parent TTX, their TEFs being in the range of 0.75-0.011. Then, different tissues of three Lagocephalus sceleratus individuals were analyzed with CBA and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The obtained TEFs were applied to the TTX analogues' concentrations obtained by LC-MS/MS analysis, providing an indication of the overall toxicity of the sample. Information about the TEFs of TTX analogues is valuable for food safety control, allowing the estimation of the risk of fish products to consumers.
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Affiliation(s)
- Mounira Alkassar
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Andres Sanchez-Henao
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Jaume Reverté
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Lourdes Barreiro
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Maria Rambla-Alegre
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Sandra Leonardo
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Manolis Mandalakis
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, 71003 Heraklion, Greece;
| | - Panagiota Peristeraki
- Institute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine Research, 71003 Heraklion, Greece;
| | - Jorge Diogène
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Mònica Campàs
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
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Finch SC, Webb NG, Boundy MJ, Harwood DT, Munday JS, Sprosen JM, Somchit C, Broadhurst RB. A Sub-Acute Dosing Study of Saxitoxin and Tetrodotoxin Mixtures in Mice Suggests That the Current Paralytic Shellfish Toxin Regulatory Limit Is Fit for Purpose. Toxins (Basel) 2023; 15:437. [PMID: 37505706 PMCID: PMC10467072 DOI: 10.3390/toxins15070437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/22/2023] [Accepted: 06/27/2023] [Indexed: 07/29/2023] Open
Abstract
Paralytic shellfish poisoning is a worldwide problem induced by shellfish contaminated with paralytic shellfish toxins. To protect human health, a regulatory limit for these toxins in shellfish flesh has been adopted by many countries. In a recent study, mice were dosed with saxitoxin and tetrodotoxin mixtures daily for 28 days showing toxicity at low concentrations, which appeared to be at odds with other work. To further investigate this reported toxicity, we dosed groups of mice with saxitoxin and tetrodotoxin mixtures daily for 21 days. In contrast to the previous study, no effects on mouse bodyweight, food consumption, heart rate, blood pressure, grip strength, blood chemistry or hematology were observed. Furthermore, no histological findings were associated with dosing in this trial. The dose rates in this study were 2.6, 3.8 and 4.9 times greater, respectively, than the highest dose of the previous study. As rapid mortality in three out of five mice was observed in the previous study, the deaths are likely to be due to the methodology used rather than the shellfish toxins. To convert animal data to that used in a human risk assessment, a 100-fold safety factor is required. After applying this safety factor, the dose rates used in the current study were 3.5, 5.0 and 6.5 times greater, respectively, than the acute reference dose for each toxin type set by the European Union. Furthermore, it has previously been proposed that tetrodotoxin be included in the paralytic shellfish poisoning suite of toxins. If this were done, the highest dose rate used in this study would be 13 times the acute reference dose. This study suggests that the previous 28-day trial was flawed and that the current paralytic shellfish toxin regulatory limit is fit for purpose. An additional study, feeding mice a diet laced with the test compounds at higher concentrations than those of the current experiment, would be required to comment on whether the current paralytic shellfish toxin regulatory limit should be modified.
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Affiliation(s)
- Sarah C. Finch
- AgResearch Ltd., Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand; (N.G.W.); (J.M.S.); (C.S.); (R.B.B.)
| | - Nicola G. Webb
- AgResearch Ltd., Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand; (N.G.W.); (J.M.S.); (C.S.); (R.B.B.)
| | - Michael J. Boundy
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (M.J.B.); (D.T.H.)
| | - D. Tim Harwood
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (M.J.B.); (D.T.H.)
| | - John S. Munday
- Department of Pathobiology, School of Veterinary Science, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand;
| | - Jan M. Sprosen
- AgResearch Ltd., Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand; (N.G.W.); (J.M.S.); (C.S.); (R.B.B.)
| | - Chanatda Somchit
- AgResearch Ltd., Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand; (N.G.W.); (J.M.S.); (C.S.); (R.B.B.)
| | - Ric B. Broadhurst
- AgResearch Ltd., Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand; (N.G.W.); (J.M.S.); (C.S.); (R.B.B.)
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10
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Al-Sulaimani S, Titelbaum NV, Ward RE, Zahran TE, Chalhoub S, Kazzi Z. Case Report of Tetrodotoxin Poisoning from Lagocephalus sceleratus in Lebanon. Int J Environ Res Public Health 2022; 19:14648. [PMID: 36429360 PMCID: PMC9690907 DOI: 10.3390/ijerph192214648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/28/2022] [Accepted: 11/03/2022] [Indexed: 06/16/2023]
Abstract
The Indo-Pacific pufferfish Lagocephalus sceleratus is a tetrodotoxin-containing species believed to have entered the Mediterranean Sea through the Suez Canal. Tetrodotoxin (TTX) is primarily found in the liver, intestine, and ovaries of L. sceleratus. We report a case of a patient with TTX poisoning from L. sceleratus consumption in Lebanon. History of ingestion, clinical presentation, and exam findings were obtained during phone-based consultation with the patient and intensive care physician. A 46-year-old male presented to a hospital in Lebanon with perioral and extremity numbness as well as dizziness 1 h after ingestion of an L. sceleratus fish. He had caught and prepared the fish himself and had eaten a skinless piece of flesh. Over the following 6 h he also developed ataxia and generalized body numbness. His treatment included systemic hydrocortisone, antihistamine, activated charcoal, and fluids. He was admitted to the intensive care unit, where he developed self-limited, stable sinus bradycardia. He was discharged home on hospital day 5 with residual lightheadedness that improved over several days. This is one of the first reported cases of tetrodotoxin poisoning due to L. sceleratus in Lebanon. Public awareness regarding the toxicity of this species after any ingestion is essential to prevent toxicity and death.
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Affiliation(s)
- Suad Al-Sulaimani
- Division of Medical Toxicology, Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA 30307, USA
- Georgia Poison Center, Atlanta, GA 30303, USA
| | - Nicholas Vincent Titelbaum
- Division of Medical Toxicology, Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA 30307, USA
- Georgia Poison Center, Atlanta, GA 30303, USA
| | - Ricardo El Ward
- Department of Internal Medicine, Faculty of Medical Sciences, Rafic Hariri University Campus, Lebanese University, Hadath 6573, Lebanon
| | - Tharwat El Zahran
- Division of Medical Toxicology, Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA 30307, USA
- Department of Emergency Medicine, Faculty of Medicine, American University of Beirut Medical Center, Beirut 1107 2020, Lebanon
| | - Sana Chalhoub
- Department of Emergency Medicine, Faculty of Medicine, American University of Beirut Medical Center, Beirut 1107 2020, Lebanon
| | - Ziad Kazzi
- Division of Medical Toxicology, Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA 30307, USA
- Georgia Poison Center, Atlanta, GA 30303, USA
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11
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Baptista M, Braga AC, Rosa R, Costa PR. Does Ocean Sunfish Mola spp. (Tetraodontiformes: Molidae) Represent a Risk for Tetrodotoxin Poisoning in the Portuguese Coast? Mar Drugs 2022; 20:md20100594. [PMID: 36286418 PMCID: PMC9604967 DOI: 10.3390/md20100594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 09/01/2022] [Accepted: 09/19/2022] [Indexed: 11/22/2022] Open
Abstract
Tetrodotoxin (TTX) is a potent neurotoxin naturally occurring in terrestrial and marine organisms such as pufferfish. Due to the risk of TTX poisoning, fish of Tetraodontidae family and other puffer-related species must not be placed in the EU markets. This restriction applies to fish of the family Molidae even though no data on toxins’ occurrence is available. In this study, the presence of TTX and its analogues was investigated in the main edible tissue (the white muscle) and the main xenobiotics storage organ (the liver) of ocean sunfish Mola spp. (n = 13) from the South Portuguese coast. HILIC-MS/MS analyses did not reveal TTX in the analyzed samples, suggesting an inexistent or very limited risk of TTX poisoning.
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Affiliation(s)
- Miguel Baptista
- MARE—Marine and Environmental Sciences Centre/ARNET—Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências, Universidade de Lisboa, 2750-005 Lisbon, Portugal
| | - Ana Catarina Braga
- IPMA—Portuguese Institute for the Ocean and Atmosphere, Av. Alfredo Magalhães Ramalho, n° 6, 1495-165 Lisbon, Portugal
- S2AQUA—Collaborative Laboratory, Association for a Sustainable and Smart Aquaculture, Av. Parque Natural da Ria Formosa s/n, 8700-194 Olhão, Portugal
| | - Rui Rosa
- MARE—Marine and Environmental Sciences Centre/ARNET—Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências, Universidade de Lisboa, 2750-005 Lisbon, Portugal
- Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, 1349-063 Lisboa, Portugal
| | - Pedro Reis Costa
- IPMA—Portuguese Institute for the Ocean and Atmosphere, Av. Alfredo Magalhães Ramalho, n° 6, 1495-165 Lisbon, Portugal
- S2AQUA—Collaborative Laboratory, Association for a Sustainable and Smart Aquaculture, Av. Parque Natural da Ria Formosa s/n, 8700-194 Olhão, Portugal
- CCMAR—Centre of Marine Sciences, Campus de Gambelas, University of Algarve, 8005-139 Faro, Portugal
- Correspondence:
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12
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Gouel P, Gatti CMI, de Haro L, Liautaud A, Langrand J, Boucaud-Maitre D. Tetrodotoxin Poisoning in Mainland France and French Overseas Territories: A Review of Published and Unpublished Cases. Toxins (Basel) 2022; 14:toxins14050351. [PMID: 35622597 PMCID: PMC9146393 DOI: 10.3390/toxins14050351] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/05/2022] [Accepted: 05/12/2022] [Indexed: 02/01/2023] Open
Abstract
Tetrodotoxin is one of the most potent neurotoxins in the aquatic world. This review of published and unpublished reports aims to describe the poisoning cases that have occurred in mainland France and overseas territories. Six articles were included, with 13 poisoning events, individuals or collective (number (n) = 53 patients). Moreover, 13 unpublished poisoning events from toxicovigilance networks were found (n = 17). All cases happened in overseas territories: French Guyana (n = 7), New Caledonia (n = 11), Reunion (n = 35) and French Polynesia (n = 17). The median age was 36 years. The most frequent signs were neurological (81.8%), digestive (54.5%) and general (52.3%). Three cases of dysgueusia and nine cases of urogenital discomfort were observed in French Polynesia. Twelve severe cases were reported, including seven deaths. Only three events (11.5%) were documented by a tetrodotoxin assay. Two families of fish accounted for 91.6% of the poisonings: 33.3% due to the Diodontidae family and 58.3% to the Tetraodontidae family. Although rare, information and collection campaigns on tetrodotoxin poisoning are, therefore, essential.
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Affiliation(s)
- Pierrick Gouel
- Service des Urgences, Centre Hospitalier de Mayotte, 97600 Mamoudzou, France;
| | - Clémence Mahana iti Gatti
- Laboratoire des Biotoxines Marines, Institut Louis Malardé, UMR 241 EIO (Ifremer, ILM, IRD, UPF), 98713 Papeete, French Polynesia;
| | - Luc de Haro
- Clinical Pharmacology, Poison Control Center, St Marguerite Hospital, 13009 Marseille, France;
| | - Alice Liautaud
- Centre Antipoison de Paris, Hôpital Fernand Widal, 75010 Paris, France; (A.L.); (J.L.)
| | - Jérôme Langrand
- Centre Antipoison de Paris, Hôpital Fernand Widal, 75010 Paris, France; (A.L.); (J.L.)
| | - Denis Boucaud-Maitre
- Department of Research an Biostatistics, University Hospital of Guadeloupe, LAMIA (EA4540) French West Indies University, 97159 Pointe-à-Pitre, France
- Correspondence:
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13
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Hanifin CT, Kudo Y, Yotsu-Yamashita M. Chemical Ecology of the North American Newt Genera Taricha and Notophthalmus. Prog Chem Org Nat Prod 2022; 118:101-130. [PMID: 35416518 DOI: 10.1007/978-3-030-92030-2_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The North American newt genera Taricha and Notophthalmus (order Caudata) are well known for the combination of potent toxicity, aposematic coloration, and striking defense postures that protects these animals from predation. This suite of traits is centered around the neurotoxin tetrodotoxin, which causes paralysis and death in metazoans by disrupting the initiation and propagation of electrical signals in the nerves and muscles. Tetrodotoxin defends newts from predation across multiple life history stages and its role in generating arms-race coevolution between Taricha newts and garter snake (genus Thamnophis) predators is well studied. However, understanding the broader picture of chemical defenses in Taricha and Notophthalmus requires an expanded comprehension of the defensive chemical ecology of tetrodotoxin that includes possible coevolutionary interactions with insect egg predators, protection against parasites, as well as mimicry complexes associated with tetrodotoxin and aposematic coloration in both genera. Herein the authors review what is known about the structure, function, and pharmacology of tetrodotoxin to explore its evolution and chemical ecology in the North American newt. Focus is made specifically on the origin and possible biosynthesis of tetrodotoxin in these taxa as well as providing an expanded picture of the web of interactions that contribute to landscape level patterns of toxicity and defense in Taricha and Notophthalmus.
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Affiliation(s)
- Charles T Hanifin
- Department of Biology, Utah State University, 320 N. Aggie Blvd, Vernal, UT, 84078, USA.
| | - Yuta Kudo
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8572, Japan
| | - Mari Yotsu-Yamashita
- Graduate School of Agricultural Science & Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8572, Japan
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14
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Christidis G, Mandalakis M, Anastasiou TI, Tserpes G, Peristeraki P, Somarakis S. Keeping Lagocephalus sceleratus off the Table: Sources of Variation in the Quantity of TTX, TTX Analogues, and Risk of Tetrodotoxication. Toxins (Basel) 2021; 13:toxins13120896. [PMID: 34941733 PMCID: PMC8706384 DOI: 10.3390/toxins13120896] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/06/2021] [Accepted: 12/10/2021] [Indexed: 11/16/2022] Open
Abstract
The invasion of the tetrodotoxin (TTX)-bearing silver-cheeked toadfish and potential poisoning due to its consumption (tetrodotoxication) threatens public safety in the Mediterranean Sea. In this study, TTX and TTX analogues of Lagocephalus sceleratus (Gmelin, 1789) were measured using liquid chromatography tandem mass spectrometry (LC-MS/MS) in fish collected off the island of Crete (Southern Mediterranean). We tested the synergistic effect of a suite of factors potentially affecting toxins' levels and tetrodotoxication risk using general and generalized linear models, respectively. The type of tissue, geographic origin (Cretan Sea, Libyan Sea), sex, and fish maturity stage were significant predictors of toxin concentrations. Mean TTX was higher in gonads and lower in muscles, higher in the Libyan Sea and in female fish, and lower in juvenile (virgin) fish. The concentration of TTX was also significantly and positively correlated with the concentration of several TTX analogues (4-epiTTX, 4,9-anhydroTTX, 11-deoxyTTX, 5,11/6,11-dideoxyTTX, 5,6,11-trideoxyTTX, 11-norTTX-6-ol). The analysis showed that fish originating from the Libyan Sea had significantly higher probability to cause tetrodotoxication in case of consumption. The variability explained by the models developed in this study was relatively low, indicating that toxin levels are hard to predict and the consumption of L. sceleratus should therefore be avoided.
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Affiliation(s)
- Georgios Christidis
- Institute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine Research (HCMR), 71500 Heraklion, Greece; (G.T.); (P.P.); (S.S.)
- Biology Department, University of Crete, 70013 Heraklion, Greece
- Correspondence: (G.C.); (M.M.)
| | - Manolis Mandalakis
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Center of Marine Research (HCMR), 71500 Heraklion, Greece;
- Correspondence: (G.C.); (M.M.)
| | - Thekla I. Anastasiou
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Center of Marine Research (HCMR), 71500 Heraklion, Greece;
| | - George Tserpes
- Institute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine Research (HCMR), 71500 Heraklion, Greece; (G.T.); (P.P.); (S.S.)
| | - Panagiota Peristeraki
- Institute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine Research (HCMR), 71500 Heraklion, Greece; (G.T.); (P.P.); (S.S.)
| | - Stylianos Somarakis
- Institute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine Research (HCMR), 71500 Heraklion, Greece; (G.T.); (P.P.); (S.S.)
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15
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Vlasenko AE, Kuznetsov VG, Malykin GV, Pereverzeva AO, Velansky PV, Yakovlev KV, Magarlamov TY. Tetrodotoxins Secretion and Voltage-Gated Sodium Channel Adaptation in the Ribbon Worm Kulikovia alborostrata (Takakura, 1898) (Nemertea). Toxins (Basel) 2021; 13:toxins13090606. [PMID: 34564610 PMCID: PMC8472881 DOI: 10.3390/toxins13090606] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/16/2021] [Accepted: 08/26/2021] [Indexed: 01/21/2023] Open
Abstract
Nemertea is a phylum of marine worms whose members bear various toxins, including tetrodotoxin (TTX) and its analogues. Despite the more than 30 years of studying TTXs in nemerteans, many questions regarding their functions and the mechanisms ensuring their accumulation and usage remain unclear. In the nemertean Kulikovia alborostrata, we studied TTX and 5,6,11-trideoxyTTX concentrations in body extracts and in released mucus, as well as various aspects of the TTX-positive-cell excretion system and voltage-gated sodium (Nav1) channel subtype 1 mutations contributing to the toxins' accumulation. For TTX detection, an immunohistological study with an anti-TTX antibody and HPLC-MS/MS were conducted. For Nav1 mutation searching, PCR amplification with specific primers, followed by Sanger sequencing, was used. The investigation revealed that, in response to an external stimulus, subepidermal TTX-positive cells released secretions actively to the body surface. The post-release toxin recovery in these cells was low for TTX and high for 5,6,11-trideoxyTTX in captivity. According to the data obtained, there is low probability of the targeted usage of TTX as a repellent, and targeted 5,6,11-trideoxyTTX secretion by TTX-bearing nemerteans was suggested as a possibility. The Sanger sequencing revealed identical sequences of the P-loop regions of Nav1 domains I-IV in all 17 studied individuals. Mutations comprising amino acid substitutions, probably contributing to nemertean channel resistance to TTX, were shown.
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16
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Okabe T, Saito R, Yamamoto K, Watanabe R, Kaneko Y, Yanaoka M, Furukoshi S, Yasukawa S, Ito M, Oyama H, Suo R, Suzuki M, Takatani T, Arakawa O, Sugita H, Itoi S. The role of toxic planocerid flatworm larvae on tetrodotoxin accumulation in marine bivalves. Aquat Toxicol 2021; 237:105908. [PMID: 34273772 DOI: 10.1016/j.aquatox.2021.105908] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/29/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
Tetrodotoxin (TTX), also known as pufferfish toxin, has been detected in marine edible bivalves worldwide. In this study, several bivalve species, Azumapecten farreri subsp. akazara, Patinopecten yessoensis and Mytilus galloprovincialis, collected from the Pacific side of the northern Japanese Islands, were studied for the accumulation of TTX in the presence of toxic planocerid larvae. LC-MS/MS analysis demonstrated that TTX was detected only in the midgut gland of A. farreri subsp. akazara. Toxic flatworm-specific PCR and direct sequencing of the amplicons showed that the DNA fragments of the Planocera multitentaculata COI gene were detected in the gut contents of the toxified bivalves. The planocerid larvae were also detected in the environmental seawaters. Toxification experiments in the aquarium demonstrated that the mussel M. galloprovincialis was also toxified by feeding on the toxic flatworm larvae. These results suggest that the source of TTX accumulation in edible bivalves is toxic flatworm larvae.
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Affiliation(s)
- Taiki Okabe
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Rion Saito
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Kohei Yamamoto
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Riku Watanabe
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Yoshiki Kaneko
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Mutsumi Yanaoka
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Seika Furukoshi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Shino Yasukawa
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Masaaki Ito
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Hikaru Oyama
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Rei Suo
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Miwa Suzuki
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Tomohiro Takatani
- Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Bunkyo 1-14, Nagasaki 852-8521, Japan
| | - Osamu Arakawa
- Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Bunkyo 1-14, Nagasaki 852-8521, Japan
| | - Haruo Sugita
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Shiro Itoi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
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17
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Bucciarelli GM, Lechner M, Fontes A, Kats LB, Eisthen HL, Shaffer HB. From Poison to Promise: The Evolution of Tetrodotoxin and Its Potential as a Therapeutic. Toxins (Basel) 2021; 13:toxins13080517. [PMID: 34437388 PMCID: PMC8402337 DOI: 10.3390/toxins13080517] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/17/2021] [Accepted: 07/20/2021] [Indexed: 11/16/2022] Open
Abstract
Tetrodotoxin (TTX) is a potent neurotoxin that was first identified in pufferfish but has since been isolated from an array of taxa that host TTX-producing bacteria. However, determining its origin, ecosystem roles, and biomedical applications has challenged researchers for decades. Recognized as a poison and for its lethal effects on humans when ingested, TTX is primarily a powerful sodium channel inhibitor that targets voltage-gated sodium channels, including six of the nine mammalian isoforms. Although lethal doses for humans range from 1.5-2.0 mg TTX (blood level 9 ng/mL), when it is administered at levels far below LD50, TTX exhibits therapeutic properties, especially to treat cancer-related pain, neuropathic pain, and visceral pain. Furthermore, TTX can potentially treat a variety of medical ailments, including heroin and cocaine withdrawal symptoms, spinal cord injuries, brain trauma, and some kinds of tumors. Here, we (i) describe the perplexing evolution and ecology of tetrodotoxin, (ii) review its mechanisms and modes of action, and (iii) offer an overview of the numerous ways it may be applied as a therapeutic. There is much to be explored in these three areas, and we offer ideas for future research that combine evolutionary biology with therapeutics. The TTX system holds great promise as a therapeutic and understanding the origin and chemical ecology of TTX as a poison will only improve its general benefit to humanity.
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Affiliation(s)
- Gary M. Bucciarelli
- Department of Ecology and Evolutionary Biology & UCLA La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA; (M.L.); (H.B.S.)
- Correspondence:
| | - Maren Lechner
- Department of Ecology and Evolutionary Biology & UCLA La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA; (M.L.); (H.B.S.)
| | - Audrey Fontes
- Natural Science Division, Pepperdine University, Malibu, CA 90263, USA; (A.F.); (L.B.K.)
| | - Lee B. Kats
- Natural Science Division, Pepperdine University, Malibu, CA 90263, USA; (A.F.); (L.B.K.)
| | - Heather L. Eisthen
- Department of Integrative Biology, Michigan State University, East Lansing, MI 48824, USA;
| | - H. Bradley Shaffer
- Department of Ecology and Evolutionary Biology & UCLA La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA; (M.L.); (H.B.S.)
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18
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Boullot F, Fabioux C, Hégaret H, Boudry P, Soudant P, Benoit E. Electrophysiological Evaluation of Pacific Oyster ( Crassostrea gigas) Sensitivity to Saxitoxin and Tetrodotoxin. Mar Drugs 2021; 19:md19070380. [PMID: 34209313 PMCID: PMC8307532 DOI: 10.3390/md19070380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/23/2021] [Accepted: 06/27/2021] [Indexed: 12/17/2022] Open
Abstract
Pacific oysters (Crassostrea gigas) may bio-accumulate high levels of paralytic shellfish toxins (PST) during harmful algal blooms of the genus Alexandrium. These blooms regularly occur in coastal waters, affecting oyster health and marketability. The aim of our study was to analyse the PST-sensitivity of nerves of Pacific oysters in relation with toxin bio-accumulation. The results show that C. gigas nerves have micromolar range of saxitoxin (STX) sensitivity, thus providing intermediate STX sensitivity compared to other bivalve species. However, theses nerves were much less sensitive to tetrodotoxin. The STX-sensitivity of compound nerve action potential (CNAP) recorded from oysters experimentally fed with Alexandrium minutum (toxic-alga-exposed oysters), or Tisochrysis lutea, a non-toxic microalga (control oysters), revealed that oysters could be separated into STX-resistant and STX-sensitive categories, regardless of the diet. Moreover, the percentage of toxin-sensitive nerves was lower, and the STX concentration necessary to inhibit 50% of CNAP higher, in recently toxic-alga-exposed oysters than in control bivalves. However, no obvious correlation was observed between nerve sensitivity to STX and the STX content in oyster digestive glands. None of the nerves isolated from wild and farmed oysters was detected to be sensitive to tetrodotoxin. In conclusion, this study highlights the good potential of cerebrovisceral nerves of Pacific oysters for electrophysiological and pharmacological studies. In addition, this study shows, for the first time, that C. gigas nerves have micromolar range of STX sensitivity. The STX sensitivity decreases, at least temporary, upon recent oyster exposure to dinoflagellates producing PST under natural, but not experimental environment.
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Affiliation(s)
- Floriane Boullot
- Service d’Ingénierie Moléculaire Pour la Santé (SIMoS), Département Médicaments et Technologies Pour la Santé (DMTS), Institut des Sciences du Vivant Frédéric Joliot, Université Paris-Saclay, CEA, ERL CNRS/CEA 9004, 91191 Gif-sur-Yvette, France;
- Laboratoire des Sciences de l’Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France; (C.F.); (H.H.); (P.S.)
| | - Caroline Fabioux
- Laboratoire des Sciences de l’Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France; (C.F.); (H.H.); (P.S.)
| | - Hélène Hégaret
- Laboratoire des Sciences de l’Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France; (C.F.); (H.H.); (P.S.)
| | - Pierre Boudry
- Centre Ifremer Bretagne, Ifremer, UMR 6539 (LEMAR) CNRS/UBO/IRD/Ifremer, ZI de la Pointe du Diable, CS 10070, 29280 Plouzané, France;
| | - Philippe Soudant
- Laboratoire des Sciences de l’Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France; (C.F.); (H.H.); (P.S.)
| | - Evelyne Benoit
- Service d’Ingénierie Moléculaire Pour la Santé (SIMoS), Département Médicaments et Technologies Pour la Santé (DMTS), Institut des Sciences du Vivant Frédéric Joliot, Université Paris-Saclay, CEA, ERL CNRS/CEA 9004, 91191 Gif-sur-Yvette, France;
- Correspondence:
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Lee CH, Le JT, Ballester-Rosado CJ, Anderson AE, Swann JW. Neocortical Slow Oscillations Implicated in the Generation of Epileptic Spasms. Ann Neurol 2021; 89:226-241. [PMID: 33068018 PMCID: PMC7855630 DOI: 10.1002/ana.25935] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 09/23/2020] [Accepted: 10/12/2020] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Epileptic spasms are a hallmark of severe seizure disorders. The neurophysiological mechanisms and the neuronal circuit(s) that generate these seizures are unresolved and are the focus of studies reported here. METHODS In the tetrodotoxin model, we used 16-channel microarrays and microwires to record electrophysiological activity in neocortex and thalamus during spasms. Chemogenetic activation was used to examine the role of neocortical pyramidal cells in generating spasms. Comparisons were made to recordings from infantile spasm patients. RESULTS Current source density and simultaneous multiunit activity analyses indicate that the ictal events of spasms are initiated in infragranular cortical layers. A dramatic pause of neuronal activity was recorded immediately prior to the onset of spasms. This preictal pause is shown to share many features with the down states of slow wave sleep. In addition, the ensuing interictal up states of slow wave rhythms are more intense in epileptic than control animals and occasionally appear sufficient to initiate spasms. Chemogenetic activation of neocortical pyramidal cells supported these observations, as it increased slow oscillations and spasm numbers and clustering. Recordings also revealed a ramp-up in the number of neocortical slow oscillations preceding spasms, which was also observed in infantile spasm patients. INTERPRETATION Our findings provide evidence that epileptic spasms can arise from the neocortex and reveal a previously unappreciated interplay between brain state physiology and spasm generation. The identification of neocortical up states as a mechanism capable of initiating epileptic spasms will likely provide new targets for interventional therapies. ANN NEUROL 2021;89:226-241.
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Affiliation(s)
- Chih-hong Lee
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
- The Cain Foundation Laboratories, The Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, USA
- Department of Neurology, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - John T. Le
- The Cain Foundation Laboratories, The Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Carlos J. Ballester-Rosado
- The Cain Foundation Laboratories, The Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Anne E. Anderson
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
- The Cain Foundation Laboratories, The Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Department of Neurology, Baylor College of Medicine, Houston, Texas, USA
| | - John W. Swann
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
- The Cain Foundation Laboratories, The Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
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20
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Whitelaw BL, Cooke IR, Finn J, da Fonseca RR, Ritschard EA, Gilbert MTP, Simakov O, Strugnell JM. Adaptive venom evolution and toxicity in octopods is driven by extensive novel gene formation, expansion, and loss. Gigascience 2020; 9:giaa120. [PMID: 33175168 PMCID: PMC7656900 DOI: 10.1093/gigascience/giaa120] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/10/2020] [Accepted: 10/06/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Cephalopods represent a rich system for investigating the genetic basis underlying organismal novelties. This diverse group of specialized predators has evolved many adaptations including proteinaceous venom. Of particular interest is the blue-ringed octopus genus (Hapalochlaena), which are the only octopods known to store large quantities of the potent neurotoxin, tetrodotoxin, within their tissues and venom gland. FINDINGS To reveal genomic correlates of organismal novelties, we conducted a comparative study of 3 octopod genomes, including the Southern blue-ringed octopus (Hapalochlaena maculosa). We present the genome of this species and reveal highly dynamic evolutionary patterns at both non-coding and coding organizational levels. Gene family expansions previously reported in Octopus bimaculoides (e.g., zinc finger and cadherins, both associated with neural functions), as well as formation of novel gene families, dominate the genomic landscape in all octopods. Examination of tissue-specific genes in the posterior salivary gland revealed that expression was dominated by serine proteases in non-tetrodotoxin-bearing octopods, while this family was a minor component in H. maculosa. Moreover, voltage-gated sodium channels in H. maculosa contain a resistance mutation found in pufferfish and garter snakes, which is exclusive to the genus. Analysis of the posterior salivary gland microbiome revealed a diverse array of bacterial species, including genera that can produce tetrodotoxin, suggestive of a possible production source. CONCLUSIONS We present the first tetrodotoxin-bearing octopod genome H. maculosa, which displays lineage-specific adaptations to tetrodotoxin acquisition. This genome, along with other recently published cephalopod genomes, represents a valuable resource from which future work could advance our understanding of the evolution of genomic novelty in this family.
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Affiliation(s)
- Brooke L Whitelaw
- Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, 1 James Cook Dr, Douglas QLD 4811 , Australia
- Sciences, Museum Victoria, 11 Nicholson St, Carlton, Victoria 3053, Australia
| | - Ira R Cooke
- College of Public Health, Medical and Vet Sciences, James Cook University,1 James Cook Dr, Douglas QLD 4811 , Australia
- La Trobe Institute of Molecular Science, La Trobe University, Plenty Rd &, Kingsbury Dr, Bundoora, Melbourne, Victoria 3086, Australia
| | - Julian Finn
- Sciences, Museum Victoria, 11 Nicholson St, Carlton, Victoria 3053, Australia
| | - Rute R da Fonseca
- Center for Macroecology, Evolution and Climate (CMEC), GLOBE Institute, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Elena A Ritschard
- Department of Neurosciences and Developmental Biology, University of Vienna,Universitätsring 1, 1010 Wien, Vienna, Austria
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - M T P Gilbert
- Center for Evolutionary Hologenomics, GLOBE Institute, University of Copenhagen, Øster Voldgade 5–7, 1350 Copenhagen, Denmark
| | - Oleg Simakov
- Department of Neurosciences and Developmental Biology, University of Vienna,Universitätsring 1, 1010 Wien, Vienna, Austria
| | - Jan M Strugnell
- Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, 1 James Cook Dr, Douglas QLD 4811 , Australia
- Department of Ecology, Environment and Evolution, La Trobe University, Plenty Rd &, Kingsbury Dr, Bundoora, Melbourne, Victoria 3086, Australia
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21
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Kudo Y, Hanifin CT, Kotaki Y, Yotsu-Yamashita M. Structures of N-Hydroxy-Type Tetrodotoxin Analogues and Bicyclic Guanidinium Compounds Found in Toxic Newts. J Nat Prod 2020; 83:2706-2717. [PMID: 32896120 DOI: 10.1021/acs.jnatprod.0c00623] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The biosynthesis of tetrodotoxin (TTX, 1), a potent neurotoxin widely distributed in marine and terrestrial metazoans, remains unresolved. A significant issue has been identifying intermediates and shunt products associated with the biosynthetic pathway of TTX. We investigated TTX biosynthesis by screening and identifying new TTX-related compounds from Cynops ensicauda popei and Taricha granulosa. Mass spectrometry (MS)-guided screening identified two new N-hydroxy TTX analogues in newts: 1-hydroxy-8-epiTTX (2) and 1-hydroxy-8-epi-5,11-dideoxyTTX (3, previously reported as 1-hydroxy-5,11-dideoxyTTX). We prepared a new analogue, 8-epi-5,11-dideoxyTTX (4), from 3 via N-OH reduction and confirmed the presence of 4 in T. granulosa using hydrophilic interaction liquid chromatography (HILIC)-LCMS. The presence of 8-epi-type TTX analogues in both Cynops and Taricha supports a branched biosynthetic pathway of terrestrial TTX, which produces 6- and 8-epimers. In addition, new bicyclic guanidinium compounds Tgr-238 (5) and Tgr-240 (6) were identified as putative shunt products of our proposed TTX biosynthesis pathway. A structural analysis of Cep-228A (7), another bicyclic compound, was performed using NMR. Based on the structures of 5-7 and their analogues, we propose a model of the shunt and metabolic pathways of the terrestrial TTX biosynthesis.
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Affiliation(s)
- Yuta Kudo
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan
- Graduate School of Agricultural Science, Tohoku University 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Charles T Hanifin
- Department of Biology, Utah State University, Uintah Basin Campus, 320 N. Aggie Boulevard (2000 W.), Vernal, Utah 84078, United States
| | - Yuichi Kotaki
- Fukushima College, 1-1 Chigoike Miyashiro, Fukushima 960-0181, Japan
| | - Mari Yotsu-Yamashita
- Graduate School of Agricultural Science, Tohoku University 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8572, Japan
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22
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Boente-Juncal A, Otero P, Rodríguez I, Camiña M, Rodriguez-Vieytes M, Vale C, Botana LM. Oral Chronic Toxicity of the Safe Tetrodotoxin Dose Proposed by the European Food Safety Authority and Its Additive Effect with Saxitoxin. Toxins (Basel) 2020; 12:E312. [PMID: 32397553 PMCID: PMC7291010 DOI: 10.3390/toxins12050312] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/06/2020] [Accepted: 05/07/2020] [Indexed: 12/25/2022] Open
Abstract
Tetrodotoxin (TTX) is a potent natural toxin causative of human food intoxications that shares its mechanism of action with the paralytic shellfish toxin saxitoxin (STX). Both toxins act as potent blockers of voltage-gated sodium channels. Although human intoxications by TTX were initially described in Japan, nowadays increasing concern about the regulation of this toxin in Europe has emerged due to its detection in fish and mollusks captured in European waters. Currently, TTX is only regularly monitored in Dutch fishery products. However, the European Food Safety Authority (EFSA) has established a safety level of 44 µg/kg TTX as the amount of toxin that did not cause adverse effects in humans. This level was extrapolated considering initial data on its acute oral toxicity and EFSA remarked the need for chronic toxicity studies to further reduce the uncertainty of future toxin regulations. Thus, in this work, we evaluated the oral chronic toxicity of TTX using the safety levels initially recommended by EFSA in order to exclude potential human health risks associated with the worldwide expanding presence of TTX. Using internationally recommended guidelines for the assessment of oral chronic toxicity, the data provided here support the proposed safety level for TTX as low enough to prevent human adverse effects of TTX even after chronic daily exposure to the toxin. However, the combination of TTX with STX at doses above the maximal exposure level of 5.3 µg/kg body weight derived by EFSA increased the lethality of TTX, thus confirming that both TTX and paralytic shellfish toxins should be taken into account to assess human health risks.
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Affiliation(s)
- Andrea Boente-Juncal
- Laboratorio de Farmacología, Farmacia e Tecnoloxía Farmacéutica, Universidade de Santiago de Compostela, Facultad de Veterinaria, Campus Universitario s/n, 27002 Lugo, Spain; (A.B.-J.); (P.O.)
| | - Paz Otero
- Laboratorio de Farmacología, Farmacia e Tecnoloxía Farmacéutica, Universidade de Santiago de Compostela, Facultad de Veterinaria, Campus Universitario s/n, 27002 Lugo, Spain; (A.B.-J.); (P.O.)
| | - Inés Rodríguez
- Laboratorios Cifga, Benigno Rivera, 56, 27003 Lugo, Spain;
| | - Mercedes Camiña
- Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain; (M.C.); (M.R.-V.)
| | - Mercedes Rodriguez-Vieytes
- Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain; (M.C.); (M.R.-V.)
| | - Carmen Vale
- Laboratorio de Farmacología, Farmacia e Tecnoloxía Farmacéutica, Universidade de Santiago de Compostela, Facultad de Veterinaria, Campus Universitario s/n, 27002 Lugo, Spain; (A.B.-J.); (P.O.)
| | - Luis M. Botana
- Laboratorio de Farmacología, Farmacia e Tecnoloxía Farmacéutica, Universidade de Santiago de Compostela, Facultad de Veterinaria, Campus Universitario s/n, 27002 Lugo, Spain; (A.B.-J.); (P.O.)
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Zhang X, Zong J, Chen S, Li M, Lu Y, Wang R, Xu H. Accumulation and Elimination of Tetrodotoxin in the Pufferfish Takifugu obscurus by Dietary Administration of the Wild Toxic Gastropod Nassarius semiplicata. Toxins (Basel) 2020; 12:toxins12050278. [PMID: 32344936 PMCID: PMC7290894 DOI: 10.3390/toxins12050278] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/23/2020] [Accepted: 04/23/2020] [Indexed: 12/21/2022] Open
Abstract
To investigate pufferfish accumulation, elimination, and distribution of tetrodotoxin (TTX), Takifugu obscurus was fed with wild TTX-containing gastropod Nassarius semiplicata to simulate the natural food chain. Three-month-old non-poisonous T. obscurus was fed with wild toxic N. semiplicata at three exposure dose for 28 days, and later, with toxin-free food until day 67. Three fish individuals from each treatment were sampled, and the distribution of TTX in different tissues was measured. The results showed that the accumulation ratio of TTX in the three exposure dose groups ranged from 35.76% to 40.20%. The accumulation ratio in the skin and liver was the highest amongst all tissues, accounting for more than 85% of the total TTX, whereas that in the kidney and gallbladder was the lowest (0.11–0.78%). Studies on the kinetic of TTX accumulation and elimination revealed that the skin was the tissue with the highest accumulation speed constant (8.06), while the liver, kidney, and intestinal tract showed the highest speed of TTX elimination. The time required for TTX reduction to reach the safety limit could be predicted by using standard elimination equations. Qualitative analysis by UPLC-MS/MS revealed the occurrence of seven TTX derivatives in T. obscurus; of these TTX, 5-deoxy TTX, 11-deoxy TTX, 4,9-anhydro TTX were found in all tested tissues.
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Affiliation(s)
- Xiaojun Zhang
- Laboratory of Aquatic Product Processing and Quality Safety, Marine Fisheries Research Institute of Zhejiang, Zhoushan 316100, China; (X.Z.); (S.C.)
- Zhejiang Province Key Lab of Mariculture & Enhancement, Zhoushan 316100, China
| | - Jingjing Zong
- School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China; (J.Z.); (Y.L.); (R.W.)
| | - Si Chen
- Laboratory of Aquatic Product Processing and Quality Safety, Marine Fisheries Research Institute of Zhejiang, Zhoushan 316100, China; (X.Z.); (S.C.)
- Zhejiang Province Key Lab of Mariculture & Enhancement, Zhoushan 316100, China
| | - Menglong Li
- Quality and Standard Research Center, Chinese Academy of Fishery Sciences, Beijing 100141, China;
| | - Yibo Lu
- School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China; (J.Z.); (Y.L.); (R.W.)
| | - Ruirui Wang
- School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China; (J.Z.); (Y.L.); (R.W.)
| | - Hanxiang Xu
- Laboratory of Aquatic Product Processing and Quality Safety, Marine Fisheries Research Institute of Zhejiang, Zhoushan 316100, China; (X.Z.); (S.C.)
- School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China; (J.Z.); (Y.L.); (R.W.)
- Correspondence: ; Tel.: +86-0580-2299-882
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Di Giovanni G, Grandi LC, Fedele E, Orban G, Salvadè A, Song W, Cuboni E, Stefani A, Kaelin-Lang A, Galati S. Acute and Chronic Dopaminergic Depletion Differently Affect Motor Thalamic Function. Int J Mol Sci 2020; 21:ijms21082734. [PMID: 32326424 PMCID: PMC7215393 DOI: 10.3390/ijms21082734] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/09/2020] [Accepted: 04/12/2020] [Indexed: 12/23/2022] Open
Abstract
The motor thalamus (MTh) plays a crucial role in the basal ganglia (BG)-cortical loop in motor information codification. Despite this, there is limited evidence of MTh functionality in normal and Parkinsonian conditions. To shed light on the functional properties of the MTh, we examined the effects of acute and chronic dopamine (DA) depletion on the neuronal firing of MTh neurons, cortical/MTh interplay and MTh extracellular concentrations of glutamate (GLU) and gamma-aminobutyric acid (GABA) in two states of DA depletion: acute depletion induced by the tetrodotoxin (TTX) and chronic denervation obtained by 6-hydroxydopamine (6-OHDA), both infused into the medial forebrain bundle (MFB) in anesthetized rats. The acute TTX DA depletion caused a clear-cut reduction in MTh neuronal activity without changes in burst content, whereas the chronic 6-OHDA depletion did not modify the firing rate but increased the burst firing. The phase correlation analysis underscored that the 6-OHDA chronic DA depletion affected the MTh-cortical activity coupling compared to the acute TTX-induced DA depletion state. The TTX acute DA depletion caused a clear-cut increase of the MTh GABA concentration and no change of GLU levels. On the other hand, the 6-OHDA-induced chronic DA depletion led to a significant reduction of local GABA and an increase of GLU levels in the MTh. These data show that MTh is affected by DA depletion and support the hypothesis that a rebalancing of MTh in the chronic condition counterbalances the profound alteration arising after acute DA depletion state.
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Affiliation(s)
- Giuseppe Di Giovanni
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida MSD 2080, Malta
- Neuroscience Division, School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - Laura Clara Grandi
- Laboratory for Biomedical Neurosciences, Neurocenter of Southern Switzerland, 6900 Taverne, Switzerland
| | - Ernesto Fedele
- Section of Pharmacology and Toxicology, Department of Pharmacy, Center of Excellence for Biomedical Research, University of Genoa, 16148 Genoa, Italy
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Gergely Orban
- Laboratory for Biomedical Neurosciences, Neurocenter of Southern Switzerland, 6900 Taverne, Switzerland
| | - Agnese Salvadè
- Laboratory for Biomedical Neurosciences, Neurocenter of Southern Switzerland, 6900 Taverne, Switzerland
| | - Wei Song
- Laboratory for Biomedical Neurosciences, Neurocenter of Southern Switzerland, 6900 Taverne, Switzerland
| | - Eleonora Cuboni
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida MSD 2080, Malta
| | - Alessandro Stefani
- Department of system medicine, Faculty of Medicine and Surgery, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Alain Kaelin-Lang
- Laboratory for Biomedical Neurosciences, Neurocenter of Southern Switzerland, 6900 Taverne, Switzerland
- Medical Faculty, University of Bern, 3008 Bern, Switzerland
- Faculty of Biomedical Sciences, Università della Svizzera Italiana, 6900 Lugano, Switzerland
| | - Salvatore Galati
- Laboratory for Biomedical Neurosciences, Neurocenter of Southern Switzerland, 6900 Taverne, Switzerland
- Faculty of Biomedical Sciences, Università della Svizzera Italiana, 6900 Lugano, Switzerland
- Center for Movement Disorders, Neurocenter of Southern Switzerland, 6900 Lugano, Switzerland
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Itoi S, Tabuchi S, Abe M, Ueda H, Oyama H, Ogata R, Okabe T, Kishiki A, Sugita H. Difference in tetrodotoxin content between two sympatric planocerid flatworms, Planocera multitentaculata and Planocera reticulata. Toxicon 2019; 173:57-61. [PMID: 31778684 DOI: 10.1016/j.toxicon.2019.11.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 11/24/2019] [Indexed: 11/20/2022]
Abstract
Planocerid flatworms and the related species (Platyhelminthes: polycladida) are known as tetrodotoxin (TTX)-bearing organisms, and they contribute to toxification of marine organisms at higher trophic levels, such as pufferfish and sea slugs. However, little is known of their biology or ecology. In this study, we therefore investigated the occurrence and toxicity of two sympatric planocerids, Planocera multitentaculata and Planocera reticulata, in intertidal zones of the central region of mainland Honshu, Japanese Islands. Planocera multitentaculata was much more abundant than P. reticulata. Body weight was greater in P. multitentaculata than in P. reticulata. Although a significant difference in TTX concentration was not observed between the two species, total TTX content per individual was greater in P. multitentaculata.
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Affiliation(s)
- Shiro Itoi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan.
| | - Sora Tabuchi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Misato Abe
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Hiroyuki Ueda
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Hikaru Oyama
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Ryuya Ogata
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Taiki Okabe
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Ayano Kishiki
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Haruo Sugita
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
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Numano S, Kudo Y, Cho Y, Konoki K, Yotsu-Yamashita M. Temporal Variation of the Profile and Concentrations of Paralytic Shellfish Toxins and Tetrodotoxin in the Scallop, Patinopecten yessoensis, Cultured in a Bay of East Japan. Mar Drugs 2019; 17:E653. [PMID: 31766477 PMCID: PMC6950525 DOI: 10.3390/md17120653] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/03/2019] [Accepted: 11/19/2019] [Indexed: 12/22/2022] Open
Abstract
Paralytic shellfish toxins (PSTs) are the major neurotoxic contaminants of edible bivalves in Japan. Tetrodotoxin (TTX) was recently detected in bivalve shellfish around the world, drawing widespread attention. In Japan, high levels of TTX were reported in the digestive gland of the scallop, Patinopecten yessoensis, in 1993; however, no new data have emerged since then. In this study, we simultaneously analyzed PSTs and TTX in scallops cultured in a bay of east Japan using hydrophilic interaction chromatography (HILIC)-MS/MS. These scallops were temporally collected from April to December 2017. The highest concentration of PSTs (182 µmol/kg, total congeners) in the hepatopancreas was detected in samples collected on May 23, lined to the cell density of the dinoflagellate, Alexandrium tamarense, in seawater around the scallops, whereas the highest concentration of TTX (421 nmol/kg) was detected in samples collected on August 22. Contrary to the previous report, temporal variation of the PSTs and TTX concentrations did not coincide. The highest concentration of TTX in the entire edible tissues was 7.3 µg/kg (23 nmol/kg) in samples obtained on August 22, which was lower than the European Food Safety Authority (EFSA)-proposed threshold, 44 µg TTX equivalents/kg shellfish meat. In addition, 12β-deoxygonyautoxin 3 was firstly identified in scallops.
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Affiliation(s)
| | | | | | | | - Mari Yotsu-Yamashita
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8572, Japan; (S.N.); (Y.K.); (Y.C.); (K.K.)
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Okabe T, Oyama H, Kashitani M, Ishimaru Y, Suo R, Sugita H, Itoi S. Toxic Flatworm Egg Plates Serve as a Possible Source of Tetrodotoxin for Pufferfish. Toxins (Basel) 2019; 11:E402. [PMID: 31373322 PMCID: PMC6669758 DOI: 10.3390/toxins11070402] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 07/09/2019] [Accepted: 07/10/2019] [Indexed: 11/26/2022] Open
Abstract
The pufferfish Takifugu niphobles (at present Takifugu alboplumbeus) possesses highly concentrated tetrodotoxin (TTX), an extremely potent neurotoxin that provides effective protection from predators, at least at the larval stages. However, the source of the toxin has remained unclear. Recently, DNA from the toxic flatworm Planocera multitentaculata was detected in the intestinal contents of juveniles and young of the pufferfish, suggesting that the flatworm contributes to its toxification at various stages of its life. In this study, we describe the behavior of the pufferfish in the intertidal zone that appears to contribute to its toxification before and during its spawning period: pufferfish were found to aggregate and ingest flatworm egg plates by scraping them off the surface of rocks. DNA analysis based on 28S rRNA and cytochrome c oxidase subunit I (COI) genes identified the egg plates as those of P. multitentaculata. Liquid chromatography with tandem mass spectrometry analysis revealed that the egg plates contain highly concentrated TTX. The feeding behavior of the pufferfish on the flatworm egg plates was also observed in the aquarium. These results suggest that pufferfish feed on the flatworm egg plate, which enables them to acquire toxicity themselves while providing their offspring with the protective shield of TTX.
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Affiliation(s)
- Taiki Okabe
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Hikaru Oyama
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Maho Kashitani
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Yuta Ishimaru
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Rei Suo
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Haruo Sugita
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Shiro Itoi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
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Kudo Y, Yotsu-Yamashita M. Isolation and Biological Activity of 8- Epitetrodotoxin and the Structure of a Possible Biosynthetic Shunt Product of Tetrodotoxin, Cep-226A, from the Newt Cynops ensicauda popei. J Nat Prod 2019; 82:1656-1663. [PMID: 31117524 DOI: 10.1021/acs.jnatprod.9b00178] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Tetrodotoxin (TTX, 1), a potent neurotoxin, has been found in various animal species in both marine and terrestrial environments. In this study, a new TTX analogue, 8- epiTTX (2), and a possible biosynthetic shunt compound of TTX, Cep-226A (3), were isolated from the newt Cynops ensicauda popei. The voltage-gated sodium ion channel (Nav) blocking activity of 2 and 6- epiTTX (4), a known analogue, were investigated by a colorimetric cell-based assay and compared with that of 1. The EC50 values for 2 and 4 were determined to be 110 ± 40 and 33 ± 11 nM, respectively, which were larger than that of 1 (1.9 ± 0.7 nM). The results indicated that the equatorial hydroxy group at C-8 in TTX significantly contributes to its Nav blocking activity, whereas the 6-epimer of TTX retains substantial activity, consistent with its previously reported toxicity in mice and binding affinity to rat brain membrane preparations. The presence of these epimers of TTX (2 and 4) and Cep-226A (3) in newts supports our hypothesis that TTX is derived from a monoterpene in terrestrial environments.
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Affiliation(s)
- Yuta Kudo
- Graduate School of Agricultural Science , Tohoku University , 468-1 Aramaki-Aza-Aoba, Aoba-ku , Sendai , Miyagi 980-8572 , Japan
- Frontier Research Institute for Interdisciplinary Sciences , Tohoku University , 6-3 Aramaki-Aza-Aoba, Aoba-ku , Sendai , Miyagi 980-8578 , Japan
| | - Mari Yotsu-Yamashita
- Graduate School of Agricultural Science , Tohoku University , 468-1 Aramaki-Aza-Aoba, Aoba-ku , Sendai , Miyagi 980-8572 , Japan
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Abal P, Louzao MC, Vilariño N, Vieytes MR, Botana LM. Acute Toxicity Assessment: Macroscopic and Ultrastructural Effects in Mice Treated with Oral Tetrodotoxin. Toxins (Basel) 2019; 11:E305. [PMID: 31146400 PMCID: PMC6628385 DOI: 10.3390/toxins11060305] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 05/24/2019] [Accepted: 05/25/2019] [Indexed: 01/30/2023] Open
Abstract
Tetrodotoxin (TTX) is an extremely toxic marine compound produced by different genera of bacteria that can reach humans through ingestion mainly of pufferfish but also of other contaminated fish species, marine gastropods or bivalves. TTX blocks voltage-gated sodium channels inhibiting neurotransmission, which in severe cases triggers cardiorespiratory failure. Although TTX has been responsible for many human intoxications limited toxicological data are available. The recent expansion of TTX from Asian to European waters and diversification of TTX-bearing organisms entail an emerging risk of food poisoning. This study is focused on the acute toxicity assessment of TTX administered to mice by oral gavage following macroscopic and microscopic studies. Necropsy revealed that TTX induced stomach swelling 2 h after administration, even though no ultrastructural alterations were further detected. However, transmission electron microscopy images showed an increase of lipid droplets in hepatocytes, swollen mitochondria in spleens, and alterations of rough endoplasmic reticulum in intestines as hallmarks of the cellular damage. These findings suggested that gastrointestinal effects should be considered when evaluating human TTX poisoning.
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Affiliation(s)
- Paula Abal
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
| | - M Carmen Louzao
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
| | - Natalia Vilariño
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
| | - Mercedes R Vieytes
- Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
| | - Luis M Botana
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
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Asakawa M, Matsumoto T, Umezaki K, Kaneko K, Yu X, Gomez-Delan G, Tomano S, Noguchi T, Ohtsuka S. Toxicity and Toxin Composition of the Greater Blue-Ringed Octopus Hapalochlaena lunulata from Ishigaki Island, Okinawa Prefecture, Japan. Toxins (Basel) 2019; 11:toxins11050245. [PMID: 31035711 PMCID: PMC6563023 DOI: 10.3390/toxins11050245] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 04/26/2019] [Accepted: 04/27/2019] [Indexed: 11/16/2022] Open
Abstract
The toxicity of the greater blue-ringed octopus Hapalochlaena lunulata, whose bite is fatal to humans, was examined to better understand and prevent deaths from accidental bites. Living specimens were collected from tide pools on Ishigaki Island, Okinawa Prefecture, Japan, in November and December of 2015, 2016, and 2017. The specimens were examined for the anatomical distribution of the toxicity, which was expressed in terms of mouse units (MU), by the standard bioassay method for tetrodotoxin (TTX) in Japan. Paralytic toxicity to mice was detected in all of the soft parts. The posterior salivary glands exhibited the highest toxicity score with a maximum level of 9276 MU/g, which was classified as "strongly toxic" (more than 1000 MU/g tissue) according to the classification of toxicity established by the Ministry of Health, Labor and Welfare of Japan, followed by the hepatopancreas (21.1 to 734.3 MU/g), gonads (not detectable to 167.6 MU/g), arms (5.3 to 130.2 MU/g), and other body areas (17.3 to 107.4 MU/g). Next, the toxin from the salivary glands was partially purified by a Sep-Pak C18 cartridge and an Amicon Ultra Centrifugal Filter with a 3000-Da cut-off, and analyzed by liquid chromatography-mass spectrometry (LC-MS) equipped with a φ2.0 × 150-mm (5 μm) TSKgel Amide-80 column (Tosoh, Tokyo, Japan) with a mixture of 16 mM ammonium formate buffer (pH 5.5) and acetonitrile (ratio 3:7, v/v) as a mobile phase. This study aimed to clarify the toxicity and the composition of TTX and its derivatives in this toxic octopus. The main toxin in this toxic octopus was identified as TTX, along with 4-epi TTX, 4, 9-anhydroTTX and 6-epi TTX. Further, the toxicity of this species is also significant from a food hygiene point of view.
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Affiliation(s)
- Manabu Asakawa
- Laboratory of Marine Bioresource Chemistry, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan.
| | - Takuya Matsumoto
- Faculty of Human Culture and Science, Prefectural University of Hiroshima, Hiroshima 734-8558, Japan.
| | - Kohei Umezaki
- Laboratory of Marine Bioresource Chemistry, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan.
| | - Kyoichiro Kaneko
- Laboratory of Marine Bioresource Chemistry, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan.
| | - Ximiao Yu
- Laboratory of Marine Bioresource Chemistry, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan.
| | - Gloria Gomez-Delan
- Department of Fisheries, Cebu Technological University-Carmen Campus, 6005 Cebu, Philippines.
| | - Satoshi Tomano
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles 90095, CA, USA.
| | - Tamao Noguchi
- Faculty of Healthcare, Tokyo Health Care University, Tokyo 154-8568, Japan.
| | - Susumu Ohtsuka
- Takehara Station, Setouchi Field Science Center, Graduate School of Biosphere Science, Hiroshima University, Takehara City, Hiroshima 725-0024, Japan.
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Katikou P. Public Health Risks Associated with Tetrodotoxin and Its Analogues in European Waters: Recent Advances after The EFSA Scientific Opinion. Toxins (Basel) 2019; 11:E240. [PMID: 31035492 PMCID: PMC6562576 DOI: 10.3390/toxins11050240] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 04/20/2019] [Accepted: 04/24/2019] [Indexed: 12/22/2022] Open
Abstract
Tetrodotoxin (TTX) and its analogues are naturally occurring toxins responsible worldwide for human intoxication cases and fatalities, mainly associated with pufferfish consumption. In the last decade, TTXs were detected in marine bivalves and gastropods from European waters. As TTXs are not regulated or monitored at EU level, their unexpected occurrence in shellfish raised concerns as a food safety hazard and revealed the necessity of a thorough assessment on the public health risks associated with their presence. For this reason, the European Food Safety Authority (EFSA) was requested by the European Commission to provide a scientific opinion, finally adopted in March 2017, according to which a provisional concentration below 44 μg TTX equivalents/kg shellfish meat, based on a large portion size of 400 g, was considered not to result in adverse effects in humans. The EFSA expert panel, however, recognized a number of shortcomings and uncertainties related to the unavailability of sufficient scientific data and provided relevant recommendations for future research to overcome these data gaps identified in order to further refine the risk assessment on TTXs. The present review aims to summarize the knowledge obtained towards addressing these recommendations in the two years following publication of the EFSA opinion, at the same time highlighting the points requiring further investigation.
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Affiliation(s)
- Panagiota Katikou
- Ministry of Rural Development and Food, Directorate General of Rural Development, Directorate of Research, Innovation and Education, Hapsa & Karatasou 1, 54626 Thessaloniki, Greece.
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Boente-Juncal A, Vale C, Cifuentes M, Otero P, Camiña M, Rodriguez-Vieytes M, Botana LM. Chronic In Vivo Effects of Repeated Exposure to Low Oral Doses of Tetrodotoxin: Preliminary Evidence of Nephrotoxicity and Cardiotoxicity. Toxins (Basel) 2019; 11:E96. [PMID: 30736354 PMCID: PMC6410189 DOI: 10.3390/toxins11020096] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/22/2019] [Accepted: 02/01/2019] [Indexed: 11/24/2022] Open
Abstract
Tetrodotoxin (TTX) is one of the most potent naturally occurring neurotoxins. InitiallyTTX was associated with human food intoxications in Japan, but nowadays, concerns about thehuman health risks posed by TTX have increased in Europe after the identification of the toxin infish, marine gastropods, and bivalves captured in European waters. Even when TTX monitoring isnot currently performed in Europe, an acute oral no observable effect level (NOAEL) of 75 μg/kghas been recently established but, to date, no studies evaluating the chronic oral toxicity of TTXhave been released, even when EFSA has highlighted the need for them. Thus, in this work, thechronic effects of low oral TTX doses (below the acute lethal dose 50) were evaluated followinginternationally adopted guidelines. The results presented here demonstrate that low oral doses ofTTX have deleterious effects on renal and cardiac tissues. Moreover, alterations in bloodbiochemistry parameters, urine production, and urinalysis data were already detected at the oraldose of 75 μg/kg after the 28 days exposure. Thus, the data presented here constitute an initialapproach for the chronic evaluation of the in vivo toxicity of tetrodotoxin after its ingestion throughcontaminated fishery products.
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Affiliation(s)
- Andrea Boente-Juncal
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
| | - Carmen Vale
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
| | - Manuel Cifuentes
- Departamento de Anatomía, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
| | - Paz Otero
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
| | - Mercedes Camiña
- Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
| | - Mercedes Rodriguez-Vieytes
- Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
| | - Luis Miguel Botana
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
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Finch SC, Boundy MJ, Harwood DT. The Acute Toxicity of Tetrodotoxin and Tetrodotoxin⁻Saxitoxin Mixtures to Mice by Various Routes of Administration. Toxins (Basel) 2018; 10:E423. [PMID: 30360529 PMCID: PMC6266834 DOI: 10.3390/toxins10110423] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 10/19/2018] [Accepted: 10/19/2018] [Indexed: 01/14/2023] Open
Abstract
Tetrodotoxin (TTX) is a potent neurotoxin associated with human poisonings through the consumption of pufferfish. More recently, TTX has been identified in bivalve molluscs from diverse geographical environments, including Europe, and is therefore recognised as an emerging threat to food safety. A recent scientific opinion of the EFSA Panel on Contaminants in the Food Chain recognised the need for further data on the acute oral toxicity of TTX and suggested that, since saxitoxin (STX) and TTX had similar modes of action, it was possible that their toxicities were additive so could perhaps be combined to yield one health-based guideline value. The present study determined the toxicity of TTX by various routes of administration. The testing of three different mixtures of STX and TTX and comparing the experimentally determined values to those predicted on the basis of additive toxicity demonstrated that the toxicities of STX and TTX are additive. This illustrates that it is appropriate to treat TTX as a member of the paralytic shellfish group of toxins. Since the toxicity of TTX was found to be the same as STX by feeding, a molar toxicity equivalence factor of 1.0 for TTX can be applied.
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Affiliation(s)
- Sarah C Finch
- AgResearch Limited, Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand.
| | | | - D Tim Harwood
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand.
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Fernández-Fernández D, Cadaveira-Mosquera A, Rueda-Ruzafa L, Herrera-Pérez S, Veale EL, Reboreda A, Mathie A, Lamas JA. Activation of TREK currents by riluzole in three subgroups of cultured mouse nodose ganglion neurons. PLoS One 2018; 13:e0199282. [PMID: 29928032 PMCID: PMC6013220 DOI: 10.1371/journal.pone.0199282] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 06/05/2018] [Indexed: 01/12/2023] Open
Abstract
Two-pore domain potassium channels (K2P) constitute major candidates for the regulation of background potassium currents in mammalian cells. Channels of the TREK subfamily are also well positioned to play an important role in sensory transduction due to their sensitivity to a large number of physiological and physical stimuli (pH, mechanical, temperature). Following our previous report describing the molecular expression of different K2P channels in the vagal sensory system, here we confirm that TREK channels are functionally expressed in neurons from the mouse nodose ganglion (mNG). Neurons were subdivided into three groups (A, Ah and C) based on their response to tetrodotoxin and capsaicin. Application of the TREK subfamily activator riluzole to isolated mNG neurons evoked a concentration-dependent outward current in the majority of cells from all the three subtypes studied. Riluzole increased membrane conductance and hyperpolarized the membrane potential by approximately 10 mV when applied to resting neurons. The resting potential was similar in all three groups, but C cells were clearly less excitable and showed smaller hyperpolarization-activated currents at -100 mV and smaller sustained currents at -30 mV. Our results indicate that the TREK subfamily of K2P channels might play an important role in the maintenance of the resting membrane potential in sensory neurons of the autonomic nervous system, suggesting its participation in the modulation of vagal reflexes.
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Affiliation(s)
- Diego Fernández-Fernández
- Department of Functional Biology and Health Sciences, Faculty of Biology–CINBIO, University of Vigo, Vigo, Galicia, Spain
- * E-mail: (DFF); (JAL)
| | - Alba Cadaveira-Mosquera
- Department of Functional Biology and Health Sciences, Faculty of Biology–CINBIO, University of Vigo, Vigo, Galicia, Spain
| | - Lola Rueda-Ruzafa
- Department of Functional Biology and Health Sciences, Faculty of Biology–CINBIO, University of Vigo, Vigo, Galicia, Spain
| | - Salvador Herrera-Pérez
- Department of Functional Biology and Health Sciences, Faculty of Biology–CINBIO, University of Vigo, Vigo, Galicia, Spain
| | - Emma L. Veale
- Medway School of Pharmacy, University of Kent, Chatham Maritime, Kent, United Kingdom
| | - Antonio Reboreda
- Department of Functional Biology and Health Sciences, Faculty of Biology–CINBIO, University of Vigo, Vigo, Galicia, Spain
| | - Alistair Mathie
- Medway School of Pharmacy, University of Kent, Chatham Maritime, Kent, United Kingdom
| | - J. Antonio Lamas
- Department of Functional Biology and Health Sciences, Faculty of Biology–CINBIO, University of Vigo, Vigo, Galicia, Spain
- * E-mail: (DFF); (JAL)
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Leão JM, Lozano-Leon A, Giráldez J, Vilariño Ó, Gago-Martínez A. Preliminary Results on the Evaluation of the Occurrence of Tetrodotoxin Associated to Marine Vibrio spp. in Bivalves from the Galician Rias (Northwest of Spain). Mar Drugs 2018; 16:E81. [PMID: 29509715 PMCID: PMC5867625 DOI: 10.3390/md16030081] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 02/23/2018] [Accepted: 03/01/2018] [Indexed: 01/01/2023] Open
Abstract
Tetrodotoxins (TTX) are a potent group of natural neurotoxins putatively produced by symbiotic microorganisms and affecting the aquatic environment. These neurotoxins have been recently found in some species of bivalves and gastropods along the European Coasts (Greece, UK, and The Netherlands) linked to the presence of high concentrations of Vibrio, in particular Vibrio parahaemolyticus. This study is focused on the evaluation of the presence of Vibrio species and TTX in bivalves (mussels, oysters, cockles, clams, scallops, and razor clams) from Galician Rias (northwest of Spain). The detection and isolation of the major Vibrio spp. and other enterobacterial populations have been carried out with the aim of screening for the presence of the pathways genes, poliketide synthase (PKS) and non-ribosomal peptide synthetase (NRPS) possibly involved in the biosynthesis of these toxins. Samples containing Vibrio spp. were analyzed by biochemical (API20E-galery) and genetic tests (PCR-RT). These samples were then screened for TTX toxicity by a neuroblastoma cell-based assay (N2a) and the presence of TTX was further confirmed by LC-MS/MS. TTX was detected in two infaunal samples. This is the first confirmation of the presence of TTX in bivalve molluscs from the Galician Rias.
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Affiliation(s)
- Jose Manuel Leão
- Department Analytical and Food Chemistry, University of Vigo, 36310 Vigo, Spain.
- EU Reference Laboratory for Marine Biotoxins, 36310 Vigo, Spain.
| | - Antonio Lozano-Leon
- Department Analytical and Food Chemistry, University of Vigo, 36310 Vigo, Spain.
- Laboratory ASMECRUZ, 36939 Bueu, Pontevedra, Spain.
| | - Jorge Giráldez
- Department Analytical and Food Chemistry, University of Vigo, 36310 Vigo, Spain.
| | - Óscar Vilariño
- Department Analytical and Food Chemistry, University of Vigo, 36310 Vigo, Spain.
- EU Reference Laboratory for Marine Biotoxins, 36310 Vigo, Spain.
| | - Ana Gago-Martínez
- Department Analytical and Food Chemistry, University of Vigo, 36310 Vigo, Spain.
- EU Reference Laboratory for Marine Biotoxins, 36310 Vigo, Spain.
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Santamaria CM, Zhan C, McAlvin B, Zurakowski D, Kohane DS. Tetrodotoxin, Epinephrine, and Chemical Permeation Enhancer Combinations in Peripheral Nerve Blockade. Anesth Analg 2017; 124:1804-1812. [PMID: 28452816 PMCID: PMC5438287 DOI: 10.1213/ane.0000000000002072] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Chemical permeation enhancers (CPEs) have the potential to improve nerve blockade by site 1 sodium channel blockers such as tetrodotoxin (TTX). Here, we investigated the efficacy and toxicity of CPE-enhanced nerve blockade across a range of TTX concentrations using 2 CPEs (sodium octyl sulfate and octyl trimethyl ammonium bromide). We also tested the hypothesis that CPEs could be used to reduce the concentrations of TTX and/or of a second adjuvant drug (in this case, epinephrine) needed to achieve prolonged local anesthesia METHODS:: Sprague-Dawley rats were injected at the sciatic nerve with combinations of TTX and CPEs, with and without epinephrine. Sensory and motor nerve blockade were assessed using a modified hot plate test and a weight-bearing test, respectively. Systemic and local toxicities of the different combinations were assessed. RESULTS Addition of increasing concentrations of TTX to fixed concentrations of CPEs produced a marked concentration-dependent improvement in the rate of successful nerve blocks and in nerve block duration. CPEs did not affect systemic toxicity. At some concentrations, the addition of sodium octyl sulfate increased the duration of block from TTX plus epinephrine, and epinephrine increased that from TTX plus CPEs. The addition of epinephrine did not cause an increase in local toxicity, and it markedly reduced systemic toxicity. CONCLUSIONS CPEs can prolong the duration of nerve blockade across a range of concentrations of TTX. CPEs could also be used to reduce the concentration of epinephrine needed to achieve a given degree of nerve block. CPEs may be useful in enhancing nerve blockade from site 1 sodium channel blockers.
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Affiliation(s)
- Claudia M. Santamaria
- Laboratory for Biomaterials and Drug Delivery, Division of Critical Care Medicine, Department of Anesthesiology, Boston Children’s Hospital, Boston, MA, United States
| | - Changyou Zhan
- Laboratory for Biomaterials and Drug Delivery, Division of Critical Care Medicine, Department of Anesthesiology, Boston Children’s Hospital, Boston, MA, United States
| | - Brian McAlvin
- Laboratory for Biomaterials and Drug Delivery, Division of Critical Care Medicine, Department of Anesthesiology, Boston Children’s Hospital, Boston, MA, United States
- Division of Medicine Critical Care, Department of Medicine, Boston Children’s Hospital, Boston, MA, United States
| | - David Zurakowski
- Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children’s Hospital, Boston, MA, United States
| | - Daniel S. Kohane
- Laboratory for Biomaterials and Drug Delivery, Division of Critical Care Medicine, Department of Anesthesiology, Boston Children’s Hospital, Boston, MA, United States
- Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children’s Hospital, Boston, MA, United States
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Pratheepa V, Vasconcelos V. Binding and Pharmacokinetics of the Sodium Channel Blocking Toxins (Saxitoxin and the Tetrodotoxins). Mini Rev Med Chem 2017; 17:320-327. [PMID: 27306745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 05/25/2016] [Accepted: 07/05/2016] [Indexed: 06/06/2023]
Abstract
Tetrodotoxin (TTX) found in diverse variety of animals including puffer fishes, some newts, frogs and limited number of non-vertebrate species (6 different phyla). The saxitoxin (STX) and the TTX are small molecules composed of 7,8,9 guanidinium and 1,2,3 guanidinium groups, respectively in their structures. These groups provide positive charge to the molecules and are believed to interact with negatively charged Glu755 and Asp400 residues in domain II and I of the sodium channel strongly. The pharmacokinetic studies (absorption, distribution and accumulation) reported on Takifugu rubripes, Takifugu pardalis, Takifugu niphobles, Takifugu vermicularis, Takifugu snyderi, etc. revealed that higher concentration of TTX is accumulated in liver than in the skin or other tissues. Although TTX is also accumulated in the skin of various marine species (secretory glands) and the excess of TTX are emitted through skin which acts as a defence agent for those species. STX showed high toxicity on crab and other animals, due to its accumulation in the tissues and resistance to the sodium channel proteins. It concluded that TTX and STX based toxicities are developed on the species by the absorption, distribution and accumulation of toxins in tissues. Also the ingestion of these species (marine species) as food may allow transferring toxin to the human being.
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Affiliation(s)
- V Pratheepa
- CIIMAR, Marine and Environmental Research Center, Porto University, Rua dos Bragas, 289, 4050-123 Porto, Portugal
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Ma XL, Zhang F, Wang YX, He CC, Tian K, Wang HG, An D, Heng B, Liu YQ. Genistein inhibition of OGD-induced brain neuron death correlates with its modulation of apoptosis, voltage-gated potassium and sodium currents and glutamate signal pathway. Chem Biol Interact 2016; 254:73-82. [PMID: 27238724 DOI: 10.1016/j.cbi.2016.05.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 05/06/2016] [Accepted: 05/25/2016] [Indexed: 01/25/2023]
Abstract
In the present study, we established an in vitro model of hypoxic-ischemia via exposing primary neurons of newborn rats to oxygen-glucose deprivation (OGD) and observing the effects of genistein, a soybean isoflavone, on hypoxic-ischemic neuron viability, apoptosis, voltage-activated potassium (Kv) and sodium (Nav) currents, and glutamate receptor subunits. The results indicated that OGD exposure reduced the viability and increased the apoptosis of brain neurons. Meanwhile, OGD exposure caused changes in the current-voltage curves and current amplitude values of voltage-activated potassium and sodium currents; OGD exposure also decreased GluR2 expression and increased NR2 expression. However, genistein at least partially reversed the effects caused by OGD. The results suggest that hypoxic-ischemia-caused neuronal apoptosis/death is related to an increase in K(+) efflux, a decrease in Na(+) influx, a down-regulation of GluR2, and an up-regulation of NR2. Genistein may exert some neuroprotective effects via the modulation of Kv and Nav currents and the glutamate signal pathway, mediated by GluR2 and NR2.
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Affiliation(s)
- Xue-Ling Ma
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Feng Zhang
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yu-Xiang Wang
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Cong-Cong He
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Kun Tian
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Hong-Gang Wang
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Di An
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Bin Heng
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yan-Qiang Liu
- College of Life Sciences, Nankai University, Tianjin 300071, China.
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Strand M, Hedström M, Seth H, McEvoy EG, Jacobsson E, Göransson U, Andersson HS, Sundberg P. The Bacterial (Vibrio alginolyticus) Production of Tetrodotoxin in the Ribbon Worm Lineus longissimus-Just a False Positive? Mar Drugs 2016; 14:md14040063. [PMID: 27023570 PMCID: PMC4849067 DOI: 10.3390/md14040063] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 03/14/2016] [Accepted: 03/15/2016] [Indexed: 12/19/2022] Open
Abstract
We test previous claims that the bacteria Vibrio alginolyticus produces tetrodotoxin (TTX) when living in symbiosis with the nemertean Lineus longissimus by a setup with bacteria cultivation for TTX production. Toxicity experiments on the shore crab, Carcinus maenas, demonstrated the presence of a paralytic toxin, but evidence from LC-MS and electrophysiological measurements of voltage-gated sodium channel-dependent nerve conductance in male Wistar rat tissue showed conclusively that this effect did not originate from TTX. However, a compound of similar molecular weight was found, albeit apparently non-toxic, and with different LC retention time and MS/MS fragmentation pattern than those of TTX. We conclude that C. maenas paralysis and death likely emanate from a compound <5 kDa, and via a different mechanism of action than that of TTX. The similarity in mass between TTX and the Vibrio-produced low-molecular-weight, non-toxic compound invokes that thorough analysis is required when assessing TTX production. Based on our findings, we suggest that re-examination of some published claims of TTX production may be warranted.
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Affiliation(s)
- Malin Strand
- Swedish Species Information Centre, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden.
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, 75237 Uppsala, Sweden.
| | - Martin Hedström
- Division of Biotechnology, Lund University, 22100 Lund, Sweden.
| | - Henrik Seth
- Department of Biological and Environmental Sciences, University of Gothenburg, 40530 Gothenburg, Sweden.
- Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 40530 Gothenburg, Sweden.
| | - Eric G McEvoy
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool L32AJ, UK.
| | - Erik Jacobsson
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, 75237 Uppsala, Sweden.
| | - Ulf Göransson
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, 75237 Uppsala, Sweden.
| | - Håkan S Andersson
- Linnaeus University Centre for Biomaterials Chemistry, Department of Chemistry and Biomedical Sciences, Linnaeus University, 39234 Kalmar, Sweden.
| | - Per Sundberg
- Department of Biological and Environmental Sciences, University of Gothenburg, 40530 Gothenburg, Sweden.
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Nagashima Y. [Dangerous marine animals. Food poisonings due to marine biotoxins of fishes]. Chudoku Kenkyu 2016; 29:3-9. [PMID: 27255017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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Wesołowski A, Płusa T. [Saxitoxins and tetrodotokxins as a new biological weapon]. Pol Merkur Lekarski 2015; 39:173-175. [PMID: 26449582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Saxitoxins (STX) and tetrodotoxins (TTX) are a group of chemical compounds produced by certain species of marine algae and fish. Lethal dose for a human is about 0.5-2.0 mg when the toxin enters the body via food, and 0.05 mg of poisoning at the time of injection. In the case of aerosol the lethal dose for human being is 5 mg/min/m(3). STX and TTX poisoning cause mostly symptoms from the nervous system in the form of: paresthesia around the lips, tongue, gums, distal segments of the limbs, headache, dysphonia, astigmatism, floating feeling, muscle weakness, paralysis of cranial and peripheral nerves. There is no specific antidote for STX and TTX. It is recommended supportive treatment.
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Affiliation(s)
- Adam Wesołowski
- Military Medical Institute in Warsaw, Department of Internal Medicine, Pulmonology and Allergology, Central Clinical Hospital of the Ministry of National Defense
| | - Tadeusz Płusa
- Military Medical Institute in Warsaw, Department of Internal Medicine, Pulmonology and Allergology, Central Clinical Hospital of the Ministry of National Defense
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Vlamis A, Katikou P, Rodriguez I, Rey V, Alfonso A, Papazachariou A, Zacharaki T, Botana AM, Botana LM. First Detection of Tetrodotoxin in Greek Shellfish by UPLC-MS/MS Potentially Linked to the Presence of the Dinoflagellate Prorocentrum minimum. Toxins (Basel) 2015; 7:1779-807. [PMID: 26008234 PMCID: PMC4448174 DOI: 10.3390/toxins7051779] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 04/25/2015] [Accepted: 05/11/2015] [Indexed: 12/21/2022] Open
Abstract
During official shellfish control for the presence of marine biotoxins in Greece in year 2012, a series of unexplained positive mouse bioassays (MBA) for lipophilic toxins with nervous symptomatology prior to mice death was observed in mussels from Vistonikos Bay–Lagos, Rodopi. This atypical toxicity coincided with (a) absence or low levels of regulated and some non-regulated toxins in mussels and (b) the simultaneous presence of the potentially toxic microalgal species Prorocentrum minimum at levels up to 1.89 × 103 cells/L in the area’s seawater. Further analyses by different MBA protocols indicated that the unknown toxin was hydrophilic, whereas UPLC-MS/MS analyses revealed the presence of tetrodotoxins (TTXs) at levels up to 222.9 μg/kg. Reviewing of official control data from previous years (2006–2012) identified a number of sample cases with atypical positive to asymptomatic negative MBAs for lipophilic toxins in different Greek production areas, coinciding with periods of P. minimum blooms. UPLC-MS/MS analysis of retained sub-samples from these cases revealed that TTXs were already present in Greek shellfish since 2006, in concentrations ranging between 61.0 and 194.7 μg/kg. To our knowledge, this is the earliest reported detection of TTXs in European bivalve shellfish, while it is also the first work to indicate a possible link between presence of the toxic dinoflagellate P. minimum in seawater and that of TTXs in bivalves. Confirmed presence of TTX, a very heat-stable toxin, in filter-feeding mollusks of the Mediterranean Sea, even at lower levels to those inducing symptomatology to humans, indicates that this emerging risk should be seriously taken into account by the EU to protect the health of shellfish consumers.
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Affiliation(s)
- Aristidis Vlamis
- Department of Pharmacology, Veterinary School, University of Santiago de Compostela, Lugo 27002, Spain.
- National Reference Laboratory on Marine Biotoxins, Veterinary Centre of Thessaloniki, Ministry of Productive Reconstruction, Environment and Energy, 3A Limnou street, GR 54627 Thessaloniki, Greece.
| | - Panagiota Katikou
- National Reference Laboratory on Marine Biotoxins, Veterinary Centre of Thessaloniki, Ministry of Productive Reconstruction, Environment and Energy, 3A Limnou street, GR 54627 Thessaloniki, Greece.
| | - Ines Rodriguez
- Department of Pharmacology, Veterinary School, University of Santiago de Compostela, Lugo 27002, Spain.
| | - Verónica Rey
- Department of Pharmacology, Veterinary School, University of Santiago de Compostela, Lugo 27002, Spain.
| | - Amparo Alfonso
- Department of Pharmacology, Veterinary School, University of Santiago de Compostela, Lugo 27002, Spain.
| | - Angelos Papazachariou
- National Reference Laboratory on Marine Biotoxins, Veterinary Centre of Thessaloniki, Ministry of Productive Reconstruction, Environment and Energy, 3A Limnou street, GR 54627 Thessaloniki, Greece.
| | - Thetis Zacharaki
- National Reference Laboratory on Marine Biotoxins, Veterinary Centre of Thessaloniki, Ministry of Productive Reconstruction, Environment and Energy, 3A Limnou street, GR 54627 Thessaloniki, Greece.
| | - Ana M Botana
- Department of Pharmacology, Veterinary School, University of Santiago de Compostela, Lugo 27002, Spain.
| | - Luis M Botana
- Department of Pharmacology, Veterinary School, University of Santiago de Compostela, Lugo 27002, Spain.
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Kadala A, Charreton M, Jakob I, Cens T, Rousset M, Chahine M, Le Conte Y, Charnet P, Collet C. Pyrethroids differentially alter voltage-gated sodium channels from the honeybee central olfactory neurons. PLoS One 2014; 9:e112194. [PMID: 25390654 PMCID: PMC4229128 DOI: 10.1371/journal.pone.0112194] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 10/13/2014] [Indexed: 11/29/2022] Open
Abstract
The sensitivity of neurons from the honey bee olfactory system to pyrethroid insecticides was studied using the patch-clamp technique on central ‘antennal lobe neurons’ (ALNs) in cell culture. In these neurons, the voltage-dependent sodium currents are characterized by negative potential for activation, fast kinetics of activation and inactivation, and the presence of cumulative inactivation during train of depolarizations. Perfusion of pyrethroids on these ALN neurons submitted to repetitive stimulations induced (1) an acceleration of cumulative inactivation, and (2) a marked slowing of the tail current recorded upon repolarization. Cypermethrin and permethrin accelerated cumulative inactivation of the sodium current peak in a similar manner and tetramethrin was even more effective. The slow-down of channel deactivation was markedly dependent on the type of pyrethroid. With cypermethrin, a progressive increase of the tail current amplitude along with successive stimulations reveals a traditionally described use-dependent recruitment of modified sodium channels. However, an unexpected decrease in this tail current was revealed with tetramethrin. If one considers the calculated percentage of modified channels as an index of pyrethroids effects, ALNs are significantly more susceptible to tetramethrin than to permethrin or cypermethrin for a single depolarization, but this difference attenuates with repetitive activity. Further comparison with peripheral neurons from antennae suggest that these modifications are neuron type specific. Modeling the sodium channel as a multi-state channel with fast and slow inactivation allows to underline the effects of pyrethroids on a set of rate constants connecting open and inactivated conformations, and give some insights to their specificity. Altogether, our results revealed a differential sensitivity of central olfactory neurons to pyrethroids that emphasize the ability for these compounds to impair detection and processing of information at several levels of the bees olfactory pathway.
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Affiliation(s)
- Aklesso Kadala
- INRA, UR 406 Abeilles et Environnement, Toxicologie Environnementale, Avignon, France
| | - Mercedes Charreton
- INRA, UR 406 Abeilles et Environnement, Toxicologie Environnementale, Avignon, France
- UMT Protection des Abeilles dans l'Environnement, Avignon, France
| | - Ingrid Jakob
- INRA, UR 406 Abeilles et Environnement, Toxicologie Environnementale, Avignon, France
| | - Thierry Cens
- CNRS, UMR 5237, Centre de Recherche de Biochimie Macromoléculaire, Université Montpellier 2, Montpellier, France
| | - Matthieu Rousset
- CNRS, UMR 5237, Centre de Recherche de Biochimie Macromoléculaire, Université Montpellier 2, Montpellier, France
| | - Mohamed Chahine
- Department of medicine, Laval University, Québec city, Canada
| | - Yves Le Conte
- INRA, UR 406 Abeilles et Environnement, Toxicologie Environnementale, Avignon, France
- UMT Protection des Abeilles dans l'Environnement, Avignon, France
| | - Pierre Charnet
- CNRS, UMR 5237, Centre de Recherche de Biochimie Macromoléculaire, Université Montpellier 2, Montpellier, France
| | - Claude Collet
- INRA, UR 406 Abeilles et Environnement, Toxicologie Environnementale, Avignon, France
- UMT Protection des Abeilles dans l'Environnement, Avignon, France
- * E-mail:
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Shen Q, Jiang T, Li N, Wang J, Han C, Zhang J, Xu J, Zhang D, Li F. [Study on tetrodotoxin detection and toxic puffer fish identification of roasted fish fillet at the retail in Beijing and Qingdao]. Wei Sheng Yan Jiu 2014; 43:944-952. [PMID: 25603604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE The roasted fish fillet sample at the retail collected in Beijing and Qingdao were detected for TTX, and the TTX positive samples was analyzed for fish species identification. METHODS TTX was tested by EUSA method and the cytochrome c oxidase I (COI) genome of TTX-positive samples was extracted and identified by DNA barcode. RESULTS Totally, 90 samples were tested by EUSA and 58 (64.4%) samples were positive for TTX with the levels ranging from 0.10 mg/kg to 63.81 mg/kg. Among the TTX positive samples, 24 (41.3%) were identified containing toxic puffer fish and 21 (87.5%) were Lagocephalus lunaris, the highly toxic puffer fish. CONCLUSION Some roasted fish fillet samples obtained from the retail in two cities were positive for TTX and contained toxic puffer fish. Based on these results, we suggest that roasted fish fillet producers should prevent toxic puffer fish from mixing in the raw material and the I regulators should strengthen the TTX surveillance and product labeling supervision of roasted fish fillet.
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Affiliation(s)
- Qing Shen
- Medical College, Qingdao University, Qingdao 266021, Shandong Province.
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Lu W, Wen B, Zhang F, Wang JH. Voltage-independent sodium channels emerge for an expression of activity-induced spontaneous spikes in GABAergic neurons. Mol Brain 2014; 7:38. [PMID: 24886791 PMCID: PMC4039334 DOI: 10.1186/1756-6606-7-38] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 05/13/2014] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Cerebral overexcitation needs inhibitory neurons be functionally upregulated to rebalance excitation vs. inhibition. For example, the intensive activities of GABAergic neurons induce spontaneous spikes, i.e., activity-induced spontaneous spikes (AISS). The mechanisms underlying AISS onset remain unclear. We investigated the roles of sodium channels in AISS induction and expression at hippocampal GABAergic neurons by electrophysiological approach. RESULTS AISS expression includes additional spike capability above evoked spikes, and the full spikes in AISS comprise early phase (spikelets) and late phase, implying the emergence of new spikelet component. Compared with the late phase, the early phase is characterized as voltage-independent onset, less voltage-dependent upstroke and sensitivity to TTX. AISS expression and induction are independent of membrane potential changes. Therefore, AISS's spikelets express based on voltage-independent sodium channels. In terms of AISS induction, the facilitation of voltage-gated sodium channel (VGSC) activation accelerates AISS onset, or vice versa. CONCLUSION AISS expression in GABAergic neurons is triggered by the spikelets based on the functional emergence of voltage-independent sodium channels, which is driven by intensive VGSCs' activities.
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Affiliation(s)
- Wei Lu
- State Key lab for Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
- Graduate School of the Chinese Academy of Sciences, Beijing 100049, China
| | - Bo Wen
- State Key lab for Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
- Graduate School of the Chinese Academy of Sciences, Beijing 100049, China
| | - Fengyu Zhang
- State Key lab for Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
| | - Jin-Hui Wang
- State Key lab for Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
- Graduate School of the Chinese Academy of Sciences, Beijing 100049, China
- Qingdao University, Medical College, 38, Dengzhou, Shandong 266021, China
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Bane V, Lehane M, Dikshit M, O'Riordan A, Furey A. Tetrodotoxin: chemistry, toxicity, source, distribution and detection. Toxins (Basel) 2014; 6:693-755. [PMID: 24566728 PMCID: PMC3942760 DOI: 10.3390/toxins6020693] [Citation(s) in RCA: 202] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 01/24/2014] [Accepted: 01/26/2014] [Indexed: 11/16/2022] Open
Abstract
Tetrodotoxin (TTX) is a naturally occurring toxin that has been responsible for human intoxications and fatalities. Its usual route of toxicity is via the ingestion of contaminated puffer fish which are a culinary delicacy, especially in Japan. TTX was believed to be confined to regions of South East Asia, but recent studies have demonstrated that the toxin has spread to regions in the Pacific and the Mediterranean. There is no known antidote to TTX which is a powerful sodium channel inhibitor. This review aims to collect pertinent information available to date on TTX and its analogues with a special emphasis on the structure, aetiology, distribution, effects and the analytical methods employed for its detection.
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Affiliation(s)
- Vaishali Bane
- Mass Spectrometry Research Centre (MSRC) and PROTEOBIO Research Groups, Department of Chemistry, Cork Institute of Technology, Rossa Avenue, Bishopstown, Cork, Ireland.
| | - Mary Lehane
- Mass Spectrometry Research Centre (MSRC) and PROTEOBIO Research Groups, Department of Chemistry, Cork Institute of Technology, Rossa Avenue, Bishopstown, Cork, Ireland.
| | | | - Alan O'Riordan
- Nanotechnology Group, Tyndall National Institute, University College Cork, Lee Maltings, Cork, Ireland.
| | - Ambrose Furey
- Mass Spectrometry Research Centre (MSRC) and PROTEOBIO Research Groups, Department of Chemistry, Cork Institute of Technology, Rossa Avenue, Bishopstown, Cork, Ireland.
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Quinlan ME, Hirasawa M. Multivesicular release underlies short term synaptic potentiation independent of release probability change in the supraoptic nucleus. PLoS One 2013; 8:e77402. [PMID: 24086774 PMCID: PMC3782434 DOI: 10.1371/journal.pone.0077402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 09/03/2013] [Indexed: 11/19/2022] Open
Abstract
Magnocellular neurons of the supraoptic nucleus receive glutamatergic excitatory inputs that regulate the firing activity and hormone release from these neurons. A strong, brief activation of these excitatory inputs induces a lingering barrage of tetrodotoxin-resistant miniature EPSCs (mEPSCs) that lasts for tens of minutes. This is known to accompany an immediate increase in large amplitude mEPSCs. However, it remains unknown how long this amplitude increase can last and whether it is simply a byproduct of greater release probability. Using in vitro patch clamp recording on acute rat brain slices, we found that a brief, high frequency stimulation (HFS) of afferents induced a potentiation of mEPSC amplitude lasting up to 20 min. This amplitude potentiation did not correlate with changes in mEPSC frequency, suggesting that it does not reflect changes in presynaptic release probability. Nonetheless, neither postsynaptic calcium chelator nor the NMDA receptor antagonist blocked the potentiation. Together with the known calcium dependency of HFS-induced potentiation of mEPSCs, our results imply that mEPSC amplitude increase requires presynaptic calcium. Further analysis showed multimodal distribution of mEPSC amplitude, suggesting that large mEPSCs were due to multivesicular glutamate release, even at late post-HFS when the frequency is no longer elevated. In conclusion, high frequency activation of excitatory synapses induces lasting multivesicular release in the SON, which is independent of changes in release probability. This represents a novel form of synaptic plasticity that may contribute to prolonged excitatory tone necessary for generation of burst firing of magnocellular neurons.
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Affiliation(s)
- Michelle E. Quinlan
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’s, Newfoundland, Canada
| | - Michiru Hirasawa
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’s, Newfoundland, Canada
- * E-mail:
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Conejo NM, Cimadevilla JM, González-Pardo H, Méndez-Couz M, Arias JL. Hippocampal inactivation with TTX impairs long-term spatial memory retrieval and modifies brain metabolic activity. PLoS One 2013; 8:e64749. [PMID: 23724089 PMCID: PMC3665627 DOI: 10.1371/journal.pone.0064749] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 04/16/2013] [Indexed: 01/16/2023] Open
Abstract
Functional inactivation techniques enable studying the hippocampal involvement in each phase of spatial memory formation in the rat. In this study, we applied tetrodotoxin unilaterally or bilaterally into the dorsal hippocampus to evaluate the role of this brain structure in retrieval of memories acquired 28 days before in the Morris water maze. We combined hippocampal inactivation with the assessment of brain metabolism using cytochrome oxidase histochemistry. Several brain regions were considered, including the hippocampus and other related structures. Results showed that both unilateral and bilateral hippocampal inactivation impaired spatial memory retrieval. Hence, whereas subjects with bilateral hippocampal inactivation showed a circular swim pattern at the side walls of the pool, unilateral inactivation favoured swimming in the quadrants adjacent to the target one. Analysis of cytochrome oxidase activity disclosed regional differences according to the degree of hippocampal functional blockade. In comparison to control group, animals with bilateral inactivation showed increased CO activity in CA1 and CA3 areas of the hippocampus during retrieval, while the activity of the dentate gyrus substantially decreased. However, unilateral inactivated animals showed decreased CO activity in Ammon's horn and the dentate gyrus. This study demonstrated that retrieval recruits differentially the hippocampal subregions and the balance between them is altered with hippocampal functional lesions.
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Affiliation(s)
- Nélida María Conejo
- Laboratory of Neuroscience, Department of Psychology, University of Oviedo, Oviedo, Spain.
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Asakawa M, Ito K, Kajihara H. Highly toxic ribbon worm Cephalothrix simula containing tetrodotoxin in Hiroshima Bay, Hiroshima Prefecture, Japan. Toxins (Basel) 2013; 5:376-95. [PMID: 23430577 PMCID: PMC3640541 DOI: 10.3390/toxins5020376] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/30/2013] [Accepted: 02/07/2013] [Indexed: 11/16/2022] Open
Abstract
In 1998, during a toxicological surveillance of various marine fouling organisms in Hiroshima Bay, Japan, specimens of the ribbon worm, Cephalothrix simula (Nemertea: Palaeonemertea) were found. These ribbon worms contained toxins with extremely strong paralytic activity. The maximum toxicity in terms of tetrodotoxin (TTX) was 25,590 mouse units (MU) per gram for the whole worm throughout the monitoring period. The main toxic component was isolated and recrystallized from an acidified methanolic solution. The crystalline with a specific toxicity of 3520 MU/mg was obtained and identified as TTX by high performance liquid chromatography (HPLC)-fluorescent detection (FLD) (HPLC-FLD), electrospray ionization-mass spectrometry (ESI-MS), infrared (IR), nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS). The highest toxicity of C. simula exceeded the human lethal dose per a single worm. A toxicological surveillance of C. simula from 1998 to 2005 indicated approximately 80% of the individuals were ranked as "strongly toxic" (≥1000 MU/g). Forty-eight percent of the specimens possessed toxicity scores of more than 2000 MU/g. Seasonal variations were observed in the lethal potency of C. simula. Specimens collected on January 13, 2000 to December 26, 2000 showed mean toxicities of 665-5300 MU/g (n = 10). These data prompted a toxicological surveillance of ribbon worms from other localities with different habitats in Japan, including Akkeshi Bay (Hokkaido) under stones on rocky intertidal beaches, as well as Otsuchi (Iwate) among calcareous tubes of serpulid polychaetes on rocky shores. Within twelve species of ribbon worms examined, only C. simula possessed extremely high toxicity. Therefore, C. simula appears to show generally high toxicity irrespective of their locality and habitat.
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Affiliation(s)
- Manabu Asakawa
- Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8528, Japan
| | - Katsutoshi Ito
- National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, Maruishi 2-17-5, Hatsukaichi, Hiroshima 739-0452, Japan; E-Mail:
| | - Hiroshi Kajihara
- Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan; E-Mail:
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Anraku K, Nonaka K, Yamaga T, Yamamoto T, Shin MC, Wakita M, Hamamoto A, Akaike N. Removal of toxin (tetrodotoxin) from puffer ovary by traditional fermentation. Toxins (Basel) 2013; 5:193-202. [PMID: 23334671 PMCID: PMC3564078 DOI: 10.3390/toxins5010193] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 01/10/2013] [Accepted: 01/11/2013] [Indexed: 11/07/2022] Open
Abstract
The amounts of puffer toxin (tetrodotoxin, TTX) extracted from the fresh and the traditional Japanese salted and fermented "Nukazuke" and "Kasuzuke" ovaries of Takifugu stictonotus (T. stictonotus) were quantitatively analyzed in the voltage-dependent sodium current (I(Na)) recorded from mechanically dissociated single rat hippocampal CA1 neurons. The amount of TTX contained in "Nukazuke" and "Kasuzuke" ovaries decreased to 1/50-1/90 times of that of fresh ovary during a salted and successive fermented period over a few years. The final toxin concentration after fermentation was almost close to the TTX level extracted from T. Rubripes" fresh muscle that is normally eaten. It was concluded that the fermented "Nukazuke" and "Kasuzuke" ovaries of puffer fish T. Stictonotus are safe and harmless as food.
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Affiliation(s)
- Kensaku Anraku
- Research Division for Life Science, Kumamoto Health Science University, 325 Izumi-machi, Kitaku, Kumamoto 861-5598, Japan; E-Mails: (K.A.); (K.N.); (T.Y.); (T.Y.); (M.-C.S); (M.W.); (A.H.)
| | - Kiku Nonaka
- Research Division for Life Science, Kumamoto Health Science University, 325 Izumi-machi, Kitaku, Kumamoto 861-5598, Japan; E-Mails: (K.A.); (K.N.); (T.Y.); (T.Y.); (M.-C.S); (M.W.); (A.H.)
| | - Toshitaka Yamaga
- Research Division for Life Science, Kumamoto Health Science University, 325 Izumi-machi, Kitaku, Kumamoto 861-5598, Japan; E-Mails: (K.A.); (K.N.); (T.Y.); (T.Y.); (M.-C.S); (M.W.); (A.H.)
| | - Takatoshi Yamamoto
- Research Division for Life Science, Kumamoto Health Science University, 325 Izumi-machi, Kitaku, Kumamoto 861-5598, Japan; E-Mails: (K.A.); (K.N.); (T.Y.); (T.Y.); (M.-C.S); (M.W.); (A.H.)
| | - Min-Chul Shin
- Research Division for Life Science, Kumamoto Health Science University, 325 Izumi-machi, Kitaku, Kumamoto 861-5598, Japan; E-Mails: (K.A.); (K.N.); (T.Y.); (T.Y.); (M.-C.S); (M.W.); (A.H.)
| | - Masahito Wakita
- Research Division for Life Science, Kumamoto Health Science University, 325 Izumi-machi, Kitaku, Kumamoto 861-5598, Japan; E-Mails: (K.A.); (K.N.); (T.Y.); (T.Y.); (M.-C.S); (M.W.); (A.H.)
| | - Ayaka Hamamoto
- Research Division for Life Science, Kumamoto Health Science University, 325 Izumi-machi, Kitaku, Kumamoto 861-5598, Japan; E-Mails: (K.A.); (K.N.); (T.Y.); (T.Y.); (M.-C.S); (M.W.); (A.H.)
| | - Norio Akaike
- Research Division for Life Science, Kumamoto Health Science University, 325 Izumi-machi, Kitaku, Kumamoto 861-5598, Japan; E-Mails: (K.A.); (K.N.); (T.Y.); (T.Y.); (M.-C.S); (M.W.); (A.H.)
- Research Division for Clinical Pharmacology, Medical Corporation, JuryoGroup, Kumamoto Kinoh Hospital, 6-8-1 Yamamuro, Kitaku, Kumamoto 860-8518, Japan
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