Characteristic Distribution of Ciguatoxins in the Edible Parts of a Grouper, Variola louti.

Naomasa Oshiro,Yoshiko Sugita-Konishi,Kyoko Kuniyoshi,Naoki Kobayashi,Takeshi Yasumoto,Hiroya Nagasawa,Hiroshi Asakura

doi:10.3390/toxins13030218

Naomasa Oshiro, Yoshiko Sugita-Konishi + Show 5 more

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https://doi.org/10.3390/toxins13030218

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Abstract

Ciguatera fish poisoning (CFP) is one of the most frequently encountered seafood poisoning syndromes; it is caused by the consumption of marine finfish contaminated with ciguatoxins (CTXs). The majority of CFP cases result from eating fish flesh, but a traditional belief exists among people that the head and viscera are more toxic and should be avoided. Unlike the viscera, scientific data to support the legendary high toxicity of the head is scarce. We prepared tissue samples from the fillet, head, and eyes taken from five yellow-edged lyretail (Variola louti) individuals sourced from Okinawa, Japan, and analyzed the CTXs by LC-MS/MS. Three CTXs, namely, CTX1B, 52-epi-54-deoxyCTX1B, and 54-deoxyCTX1B, were confirmed in similar proportions. The toxins were distributed nearly evenly in the flesh, prepared separately from the fillet and head. Within the same individual specimen, the flesh in the fillet and the flesh from the head, tested separately, had the same level and composition of toxins. We, therefore, conclude that flesh samples for LC-MS/MS analysis can be taken from any part of the body. However, the tissue surrounding the eyeball displayed CTX levels two to four times higher than those of the flesh. The present study is the first to provide scientific data demonstrating the high toxicity of the eyes.

Highlights

Ciguatera fish poisoning (CFP) is one of the most frequently encountered seafood poisoning syndromes; it is caused by the consumption of the marine finfish contaminated with ciguatoxins (CTXs) [1,2,3,4]
We reported the regional and species-specific features of the CTX profiles of fish in the Pacific using liquid chromatography–tandem mass spectrometry (LC-MS/MS)
The present study demonstrates that flesh samples for toxin analysis can be arbitrarily taken from all parts of the body of V. louti except the eye areas

Summary

Introduction

Ciguatera fish poisoning (CFP) is one of the most frequently encountered seafood poisoning syndromes; it is caused by the consumption of the marine finfish contaminated with ciguatoxins (CTXs) [1,2,3,4]. CTXs bind to receptor-site 5 of the alpha subunit of the voltage-gated sodium channel and cause hyperexcitability of the nerve membrane [5]. CFP is associated with gastrointestinal, cardiovascular, and neurological disorders, and more than 170 symptoms and signs have been reported [1]. The patients recover within a few days in mild cases, but the symptoms last for months or years in severe cases [5]. CFP mostly occurs in tropical and subtropical regions of the Pacific, the Indian Ocean, and the Caribbean Sea and is commonly reported in the South Pacific islands, including French

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