The Incidence of Tetrodotoxin and Its Analogs in the Indian Ocean and the Red Sea

Abstract

Tetrodotoxin (TTX) is a potent marine neurotoxin with bacterial origin. To date, around 28 analogs of TTX are known, but only 12 were detected in marine organisms, namely TTX, 11-oxoTTX, 11-deoxyTTX, 11-norTTX-6(R)-ol, 11-norTTX-6(S)-ol, 4-epiTTX, 4,9-anhydroTTX, 5,6,11-trideoxyTTX, 4-CysTTX, 5-deoxyTTX, 5,11-dideoxyTTX, and 6,11-dideoxyTTX. TTX and its derivatives are involved in many cases of seafood poisoning in many parts of the world due to their occurrence in different marine species of human consumption such as fish, gastropods, and bivalves. Currently, this neurotoxin group is not monitored in many parts of the world including in the Indian Ocean area, even with reported outbreaks of seafood poisoning involving puffer fish, which is one of the principal TTX vectors know since Egyptian times. Thus, the main objective of this review was to assess the incidence of TTXs in seafood and associated seafood poisonings in the Indian Ocean and the Red Sea. Most reported data in this geographical area are associated with seafood poisoning caused by different species of puffer fish through the recognition of TTX poisoning symptoms and not by TTX detection techniques. This scenario shows the need of data regarding TTX prevalence, geographical distribution, and its vectors in this area to better assess human health risk and build effective monitoring programs to protect the health of consumers in Indian Ocean area.

First record of the oceanic puffer Lagocephalus lagocephalus (Linnaeus, 1758) from the Syrian marine waters (eastern Mediterranean)

“…The poisonous nature of this puffer fish is largely due to the tetrodotoxin (TTX) and paralytic saxitoxin contents of their internal organs (liver, ovary, intestine, skin…etc.). Tetrodotoxin is a potent neurotoxin that blocks the voltage-gated sodium channels on the surface of nerve membranes: It is 100 times more potent than cyanide, and one puffer fish may be enough to kill 30 adults (Santhanam 2018;Tamele et al 2019 (Rahman et al 2014;Galiya et al 2015;Ali 2018). The oceanic puffer Lagocephalus lagocephalus (Linnaeus, 1758) is a native tetraodontid species that can be found in many Mediterranean coasts (Froese and Pauly 2019), but had not been recorded before in the marine waters of Syria (Ali 2018).…”

Acute Toxicity Assessment: Macroscopic and Ultrastructural Effects in Mice Treated with Oral Tetrodotoxin

“…The TTX geographic expansion to Europe and diversification of TTX-bearing organisms (gastropods, crustaceans, and molluscs) [3] has made this toxin recognized as an emerging risk by European regulators [29]. In any case, the symptoms of poisoning due to the consumption of TTX vectors depend on the amount of toxin ingested [31]. Normally, onset of clinical signs begin very fast, within 30 min to 3 hours after consumption of TTX vectors, indicating an acute intoxication [6,31,32].…”

“…In any case, the symptoms of poisoning due to the consumption of TTX vectors depend on the amount of toxin ingested [31]. Normally, onset of clinical signs begin very fast, within 30 min to 3 hours after consumption of TTX vectors, indicating an acute intoxication [6,31,32].…”

On the occurrence and health risks of the Silver-cheeked Toadfish (Lagocephalus sceleratus Gmelin, 1789) in the marine ecosystem of the Gaza Strip, Palestine

“…This may contribute to lower the risks of poisoning by consumers. In contrast, such gonads and livers are considered vey delicious in certain areas of the world, and their eating by some people causes hospitalization and even deaths (Arakawa et al 2010;Nader et al 2012 andTamele et al 2019).…”

“…Although many species of pufferfishes are economically important and edible in many countries of the Mediterranean region, the Silver-cheeked Toadfish, in particular, is not among the commercial species because of its high toxicity. Therefore, it has been considered to be a serious hazard to consumers since it contains a strong and potent marine toxin called Tetrodotoxin (TTX), which can be very poisonous and even lethal to humans (Sims and Ostman, 1986;Ahasan et al 2004;Zaki 2004;Bentur et al 2008;Noguchi and Arakawa 2008;Saoudi et al 2008;Chamandi et al 2009;Katikou et al 2009;Arakawa et al 2010;Islam et al 2011;Kheifets et al 2012;Nader et al 2012;Kosker et al 2016;Tamele et al 2019).…”