Pufferfish poisoning poses a serious threat to human health, with numerous incidents reported worldwide. The toxicity of pufferfish is primarily attributed to tetrodotoxins (TTXs) and paralytic shellfish toxins (PSTs), both of which are potent blockers of voltage-gated sodium channels. However, the toxicity profiles of individual TTX analogues and the presence of PSTs in certain pufferfish species remain poorly understood, creating challenges for food safety management and risk assessment.

Two recent papers from Monica Campàs’ group address this critical issue by improving our understanding of these toxins in pufferfish. The authors utilized an automated patch clamp system (the Patchliner) to assess the effects of five TTX analogues and two PSTs – saxitoxin (STX) and its analogue decarbamoylsaxitoxin (dcSTX) – on voltage-gated sodium channels in Neuro-2a cells. From this data, they determined toxicity equivalency factors (TEFs) for the TTX and STX analogues, showing that all analogues were less toxic than TTX or STX, respectively.

The authors also demonstrated that TEFs derived from APC experiments could be used as correction factors in LC−MS/MS data, making it easier to turn analytical data into useful toxicological insights.

Importantly, although previous research had primarily associated pufferfish toxicity with TTX, these studies mark the first record of PSTs in Mediterranean pufferfish L. lagocephalus. The presence of STX and dcSTX in pufferfish, particularly in the liver, suggests a growing risk to seafood safety in this region.

These studies offer new insights into the presence of PSTs in Mediterranean pufferfish and provide a novel approach for assessing the toxicity of TTX analogues. The successful application of automated patch clamp for toxicological assessment of TTX analogues and the establishment of TEFs offer valuable tools for translating analytical data into meaningful toxicological information.

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Find the two articles here: https://pubs.acs.org/doi/10.1021/acs.jafc.4c04321 and https://www.sciencedirect.com/science/article/abs/pii/S0045653524019489

Learn more about the Patchliner, the most versatile automated patch clamp system on the market: https://www.nanion.de/products/patchliner/