yessotoxin and Diarrhea

Yessotoxin (YTX) is a marine polyether toxin that was first isolated in 1986 from the scallop Patinopecten yessoensis. Subsequently, it was reported that YTX is produced by the dinoflagellates Protoceratium reticulatum, Lingulodinium polyedrum and Gonyaulax spinifera. YTXs have been associated with diarrhetic shellfish poisoning (DSP) because they are often simultaneously extracted with DSP toxins, and give positive results when tested in the conventional mouse bioassay for DSP toxins. However, recent evidence suggests that YTXs should be excluded from the DSP toxins group, because unlike okadaic acid (OA) and dinophyisistoxin-1 (DTX-1), YTXs do not cause either diarrhea or inhibition of protein phosphatases. In spite of the increasing number of molecular studies focused on the toxicity of YTX, the precise mechanism of action is currently unknown. Since the discovery of YTX, almost forty new analogues isolated from both mussels and dinoflagellates have been characterized by NMR or LC-MS/MS techniques. These studies indicate a wide variability in the profile and the relative abundance of YTXs in both, bivalves and dinoflagellates. This review covers current knowledge on the origin, producer organisms and vectors, chemical structures, metabolism, biosynthetic origin, toxicological properties, potential risks to human health and advances in detection methods of YTXs.

Topics: Animals; Bivalvia; Diarrhea; Dinoflagellida; Marine Toxins; Maximum Allowable Concentration; Mollusk Venoms; Oxocins; Public Health; Shellfish Poisoning; Structure-Activity Relationship

More than 200 people in China suffered illness with symptoms of diarrhetic shellfish poisoning (DSP) following consumption of mussels (Mytilus galloprovincialis). The event occurred in the cities of Ningbo and Ningde near the East China Sea in May, 2011. LC-MS/MS analysis showed that high concentrations of okadaic acid, dinophysistoxin-1, and their acyl esters were responsible for the incidents. The total concentration was more than 40 times the EU regulatory limit of 160 μg OA eq./kg. Pectentoxin-2 and its seco-acids were also present in the mussels. Additionally, yessotoxins were found to be responsible for positive mouse bioassay results on scallop (Patinopecten yessoensis) and oyster (Crassostrea talienwhanensis) samples collected from the North Yellow Sea in June, 2010. This work shows that high levels of lipophilic toxins can accumulate in shellfish from the Chinese coast and it emphasises that adequate chemical analytical methodologies are needed for monitoring purposes. Further research is required to broaden the knowledge on the occurrence of lipophilic toxins in Chinese shellfish.

Topics: Abdominal Pain; Alveolata; Animals; China; Diarrhea; Diet; Disease Outbreaks; Food Contamination; Humans; Marine Toxins; Mollusk Venoms; Mytilus; Okadaic Acid; Ostreidae; Oxocins; Pacific Ocean; Pectinidae; Pyrans; Seafood; Shellfish Poisoning

Topics: Acrylamides; Animals; Cnidarian Venoms; Cytoskeleton; Diarrhea; Humans; Marine Toxins; Mollusk Venoms; Okadaic Acid; Oxocins; Saxitoxin; Sodium-Potassium-Exchanging ATPase

Monthly concentrations of diarrhetic shellfish poisoning (DSP) toxins and yessotoxin (YTX) in mussels from the coast to the inner part of the Sognefjord were determined. Mussels from nine locations were sampled from March to November 1997. The DSP toxins and YTX were analysed by a colorimetric protein phosphatase 2A (PP2A) inhibition assay or fluorometric HPLC, respectively. The mouse bioassay for DSP toxins was performed including either chloroform or diethyl ether in the final step of extraction. Using ether in the final step normally facilitated extraction of the DSP toxins, okadaic acid (OA) and dinophysis toxin-1 (DTX-1), while chloroform extraction included a wider spectrum of toxins, including YTX and a fast acting toxin(s) with neurotoxic effects. The concentrations of DSP toxins and YTX in mussels increased with distance from the coast. The highest concentrations of YTX (574 microg YTX/100 g mussel meat) and diarrhetic toxins (349 microg OA equivalents/100 g mussel meat) were measured in May and August, respectively, at locations in the inner part of the fjord. Since concentrations of DSP toxins and YTX in mussels increased with distance from the coast, the locations for mussel farming in the Sognefjord close to the coast, seem to be preferable.

Topics: Animals; Bivalvia; Chromatography, High Pressure Liquid; Diarrhea; Enzyme Inhibitors; Ethers, Cyclic; Eukaryota; Female; Marine Toxins; Mice; Mollusk Venoms; Norway; Oxocins; Phospholipases A; Seasons; Shellfish

Yessotoxin (YTX), originally found in association with diarrhetic shellfish poisoning (DSP), caused neither intestinal fluid accumulation nor inhibition of protein phosphatase 2A. Orally, YTX was not lethal to mice at 1.0 mg/kg. The toxin showed weak cytotoxic and antifungal activities. Neither hemolytic nor ichthyotoxic effect was observed.

Topics: Animals; Animals, Suckling; Anti-Infective Agents; Cell Survival; Diarrhea; Dose-Response Relationship, Drug; Enzyme Inhibitors; Ethers, Cyclic; Hemolysis; Male; Mice; Mollusk Venoms; Oxocins; Phosphoprotein Phosphatases; Protein Phosphatase 2; Zebrafish

Mussels exposed to dinoflagellates may represent a human health risk due to accumulation of a variety of algal toxins. In several parts of the world, algal toxins leading to diarrhea (diarrhetic shellfish poisons, DSP) are found in mussels for extended periods of the year. Routine monitoring of these toxins involves ip injections in mice. Chemical analytical methods have been developed for only some of the toxins in question, namely, those giving diarrhea. Other toxins in the DSP complex are not easily detected by analytical methods. In this report we show that freshly prepared hepatocytes from rats are a convenient means to differentiate between the toxins that give diarrhea and those that do not. Consequently, hepatocytes can be useful in both screening and as a tool in the process of developing analytical methods. Freshly prepared hepatocytes might be useful in combination either with the mouse bioassay or with chemical analytical methods.

Topics: Animals; Bacterial Toxins; Bivalvia; Cells, Cultured; Cyanobacteria Toxins; Diarrhea; Dose-Response Relationship, Drug; Ethers, Cyclic; L-Lactate Dehydrogenase; Liver; Macrolides; Male; Marine Toxins; Microcystins; Microscopy, Electron, Scanning; Mollusk Venoms; Okadaic Acid; Oxocins; Pyrans; Rats; Shellfish