Saxitoxin and Other Paralytic Toxins: Toxicological Profile

Suárez‐Isla, Benjamin A.

doi:10.1007/978-94-007-6419-4_25

Cited by 4 publications

(3 citation statements)

References 75 publications

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“…While, the risk to humans from PSTs is wellunderstood [ 27 ], and management systems are in place to limit the risk of intoxications from shellfish consumption, PSTs can also impact animal health with negative effects on a wide range of marine organisms [ 28 ], including fish [ 29 , 30 , 31 ], whales and seals [ 32 , 33 ], otters [ 34 ], sea birds [ 35 , 36 ], sea urchins [ 37 ], starfish [ 38 ], gastropods [ 39 ], as well as bivalve molluscs [ 40 , 41 ]. Furthermore, there have been instances of PSTs affecting terrestrial animals.…”

Section: Introductionmentioning

confidence: 99%

Multiple New Paralytic Shellfish Toxin Vectors in Offshore North Sea Benthos, a Deep Secret Exposed

et al. 2020

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In early 2018, a large easterly storm hit the East Anglian coast of the UK, colloquially known as the ‘Beast from the East’, which also resulted in mass strandings of benthic organisms. There were subsequent instances of dogs consuming such organisms, leading to illness and, in some cases, fatalities. Epidemiological investigations identified paralytic shellfish toxins (PSTs) as the cause, with toxins present in a range of species and concentrations exceeding 14,000 µg STX eq./kg in the sunstar Crossaster papposus. This study sought to better elucidate the geographic spread of any toxicity and identify any key organisms of concern. During the summers of 2018 and 2019, various species of benthic invertebrates were collected from demersal trawl surveys conducted across a variety of locations in the North Sea. An analysis of the benthic epifauna using two independent PST testing methods identified a ‘hot spot’ of toxic organisms in the Southern Bight, with a mean toxicity of 449 µg STX eq./kg. PSTs were quantified in sea chervil (Alcyonidium diaphanum), the first known detection in the phylum bryozoan, as well as eleven other new vectors (>50 µg STX eq./kg), namely the opisthobranch Scaphander lignarius, the starfish Anseropoda placenta, Asterias rubens, Luidia ciliaris, Astropecten irregularis and Stichastrella rosea, the brittlestar Ophiura ophiura, the crustaceans Atelecyclus rotundatus and Munida rugosa, the sea mouse Aphrodita aculeata, and the sea urchin Psammechinus miliaris. The two species that showed consistently high PST concentrations were C. papposus and A. diaphanum. Two toxic profiles were identified, with one dominated by dcSTX (decarbamoylsaxitoxin) associated with the majority of samples across the whole sampling region. The second profile occurred only in North-Eastern England and consisted of mostly STX (Saxitoxin) and GTX2 (gonyautoxin 2). Consequently, this study highlights widespread and variable levels of PSTs in the marine benthos, together with the first evidence for toxicity in a large number of new species. These findings highlight impacts to ‘One Health’, with the unexpected sources of toxins potentially creating risks to animal, human and environmental health, with further work required to assess the severity and geographical/temporal extent of these impacts.

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Section: Introductionmentioning

confidence: 99%

Multiple New Paralytic Shellfish Toxin Vectors in Offshore North Sea Benthos, a Deep Secret Exposed

et al. 2020

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“…Mouse NOAELs are 163 and 341 μg/kg BW upon administration of STX via gavage and feeding, respectively, and LD 50 values upon gavage dosing are 356 and 370 μg/kg BW, while upon feeding, the LD 50 values are 853 and 958 μg/kg BW. , For humans, reported NOAELs are 0.5 and 0.7 μg STX equivalents/kg BW. , In addition, Arnich and Thébault collected epidemiological data from previous intoxication cases associated with the ingestion of shellfish contaminated with STX-group toxins and built a dose–symptom model, resulting in identification of a dose of 0.37 μg STX equivalents/kg BW as the lower critical dose with a probability higher than 10% of showing symptoms (LCD 10 ). The human LD 50 was reported as 5.7 μg/kg BW by Nguyen et al or estimated by Suarez-Isla as 1–4 mg depending upon age and physical conditions of the individual, amounting to 16.7–66.7 μg/kg BW assuming a body weight of 60 kg for the average individual. All these data are also presented in Figure for comparison to the predicted in vivo dose–response curves, which shows that the predicted curves derived from available in vitro concentration–response datasets are in line with these PODs.…”

Section: Resultsmentioning

confidence: 99%

Integrating In Vitro Data and Physiologically Based Kinetic Modeling to Predict and Compare Acute Neurotoxic Doses of Saxitoxin in Rats, Mice, and Humans

Chen

Noorlander

Wesseling

et al. 2023

Environ. Sci. Technol.

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Current climate trends are likely to expand the geographic distribution of the toxigenic microalgae and concomitant phycotoxins, making intoxications by such toxins a global phenomenon. Among various phycotoxins, saxitoxin (STX) acts as a neurotoxin that might cause severe neurological symptoms in mammals following consumptions of contaminated seafood. To derive a point of departure (POD) for human health risk assessment upon acute neurotoxicity induced by oral STX exposure, a physiologically based kinetic (PBK) modeling-facilitated quantitative in vitro to in vivo extrapolation (QIVIVE) approach was employed. The PBK models for rats, mice, and humans were built using parameters from the literature, in vitro experiments, and in silico predictions. Available in vitro toxicity data for STX were converted to in vivo dose–response curves via the PBK models established for these three species, and POD values were derived from the predicted curves and compared to reported in vivo toxicity data. Interspecies differences in acute STX toxicity between rodents and humans were found, and they appeared to be mainly due to differences in toxicokinetics. The described approach resulted in adequate predictions for acute oral STX exposure, indicating that new approach methodologies, when appropriately integrated, can be used in a 3R-based chemical risk assessment paradigm.

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“…The oral LD 50 of STX for humans is 5.7 μg/kg, or approximately 0.57 mg of saxitoxin for a 100 kg human, and the lethal dose by injection is approximately 0.6 μg/kg. The human toxicity of aerosolized saxitoxin is estimated to be 5 mg min/m 3 . , Contrary to ricin, there are no cases of alleged use of saxitoxin for purposes of chemical warfare or terrorism …”

Section: Saxitoxinmentioning

confidence: 99%

Ricin and Saxitoxin: Two Natural Products That Became Chemical Weapons

Sierra

Martínez‐Álvarez

2020

J. Chem. Educ.

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Ricin and saxitoxin are highly toxic natural products that have been weaponized and are included in Schedule 1 of the Chemical Weapons Convention. Both toxins are available from natural sources, and they can be used as homemade chemical weapons for terrorist purposes. The availability of ricin is high because the shrub Ricinus communis is widespread worldwide, and access to Ricinus seeds (castor beans are the source of ricin) is easy; its use for illegal purposes has happened several times. Contrary to ricin, saxitoxin is difficult to isolate from natural sources, or to obtain by chemical synthesis, which makes the use of saxitoxin in terrorist actions unlikely. Additionally, the mechanisms of action of both toxins are totally different. Ricin targets the ribosome while saxitoxin targets the Na-channels in the cell membrane. In both cases cell death occurs very efficiently. The potency of both chemicals makes ricin and saxitoxin excellent leads for the development of new drugs for rightful applications, including, among others, treatment of cancer or anesthesia.

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Saxitoxin and Other Paralytic Toxins: Toxicological Profile

Cited by 4 publications

References 75 publications

Multiple New Paralytic Shellfish Toxin Vectors in Offshore North Sea Benthos, a Deep Secret Exposed

Multiple New Paralytic Shellfish Toxin Vectors in Offshore North Sea Benthos, a Deep Secret Exposed

Integrating In Vitro Data and Physiologically Based Kinetic Modeling to Predict and Compare Acute Neurotoxic Doses of Saxitoxin in Rats, Mice, and Humans

Ricin and Saxitoxin: Two Natural Products That Became Chemical Weapons

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