Concentrations of Tetrodotoxin (TTX) and Its Analogue 4,9-Anhydro TTX in Different Tissues of the Silver-Cheeked Pufferfish (Lagocephalus sceleratus, Gmelin, 1789) Caught in the South-Eastern Mediterranean Sea, Lebanon.

Abed El Rahman Hassoun,Milad Fakhri,Céline Mahfouz,Romana Roje-Busatto,Sharif Jemaa,Ivana Ujević,Nikša Nazlić

doi:10.3390/toxins14020123

Abstract

Pufferfishes are among the best-known marine organisms that accumulate marine biotoxins such as Tetrodotoxin (TTX). In the Mediterranean Sea, the silver-cheeked toadfish Lagocephalus sceleratus is the most reported TTX-bearer, causing many fatal and non-fatal cases. In Lebanon, no previous studies have measured TTX levels although the possibility of TTX-poisoning is high since L. sceleratus is caught in different sizes and can be mistaken with other small fishes. Hence, this study reports TTX and its analogue 4,9-anhydro TTX in L. sceleratus collected from Lebanese waters in the Eastern Mediterranean Sea. The results show that TTX concentrations in fish tissues varied between 0.10 and 252.97 µg/g, while those of 4,9-anhydro TTX oscillated between 0.01 and 43.01 µg/g. Internal organs of L. sceleratus were the most toxic parts of its body, with the highest TTX levels found in gonads (mainly ovaries) and liver, followed by the muscles and skin with concentrations always exceeding the safety level. Toxicity fluctuations of L. sceleratus, its expansion, ecological and economic effects were also elucidated. Based on the present findings, it has been confirmed that L. sceleratus constitutes a health, ecological and economic risks, and therefore its trade in seafood markets should be banned to avoid any potential intoxication.

Highlights

Introduction iationsMarine biotoxins are naturally existing chemicals produced by toxic algae that can accumulate in marine biota [1]
Our results demonstrate the potential toxicity of L. sceleratus when consumed, since a couple of accidental intoxication cases related to its consumption were recently reported in Lebanon [29,49]
Results in this study demonstrate the relationship between the high toxicity of L. sceleratus and the size of fish—the bigger the fish the more toxic it is, which is in agreement with results found in other studies [11]

Summary

Introduction

Introduction iationsMarine biotoxins are naturally existing chemicals produced by toxic algae that can accumulate in marine biota [1]. Some biotoxins are thought to be produced primarily by marine bacteria These toxins may bioaccumulate through the food chain or in combination with parasitism or symbiosis (a part of the animal’s natural microbiome), intoxicating detritus feeders, small carnivores, omnivores/scavengers, and organisms higher up the food chain [2]. This is the case of Tetrodotoxin (TTX), a non-protein, weakly basic organic, and low molecular weight compound that is soluble in water and acidic environments, colorless, odorless, tasteless, and heat resistant [3,4,5]. It acts by binding and blocking the voltage-gated

Methods

Discussion

Conclusion