Study of possible combined toxic effects of azaspiracid-1 and okadaic acid in mice via the oral route.

Toxins from the okadaic acid (OA) and azaspiracid (AZA) group cause considerable negative health effects in consumers when present in shellfish above certain levels. The main symptoms, dominated by diarrhoea, are caused by damage to the gastrointestinal (GI) tract. Even though OA and AZAs exert toxicity via different mechanisms, it is important to find out whether they may enhance the health effects if present together since they act on the same organs and are regulated individually.

Pinnatoxins and spirolides in Norwegian blue mussels and seawater.

Fast-acting cyclic imines belonging to the pinnatoxin and pteriatoxin group of toxins were originally identified in shellfish of the genera Pinna and Pteria in Japan, after food poisoning events in China linked to consumption of Pinna spp. Recently, a range of new and known pinnatoxin analogs has been identified in shellfish, sediment, and seawater samples from Australia and New Zealand. Although the structurally closely-related spirolide toxins are better known, and have a worldwide distribution including Norway and other parts of Europe, the presence of pinnatoxins has not been reported in European waters or shellfish.

Combined oral toxicity of azaspiracid-1 and yessotoxin in female NMRI mice.

For many years, the presence of yessotoxins (YTXs) in shellfish has contributed to the outcome of the traditional mouse bioassay and has on many occasions caused closure of shellfisheries. Since YTXs do not appear to cause diarrhoea in man and exert low oral toxicity in animal experiments, it has been suggested that they should be removed from regulation. Before doing so, it is important to determine whether the oral toxicity of YTXs is enhanced when present together with shellfish toxins known to cause damage to the gastrointestinal tract.

Sub-lethal dosing of azaspiracid-1 in female NMRI mice.

The main aim of this study was to examine absorption and pathological effects of a single sub-lethal dose of the marine biotoxin azaspiracid-1 (AZA1) in mice after oral intubation. When the mice received AZA1 at doses of 100, 200 or 300 μg/kg body weight (b.w.

Effect of mouse strain and gender on LD(50) of yessotoxin.

The aim of the present study was to determine whether the intraperitoneal LD(50) for yessotoxin (YTX) in mice varies with strain or gender. Thirty-six male and 36 female mice, of body weight 16-20 g, from each of the strains ICR (CD-1), Swiss (CFW-1) and NMRI were employed. They were not fasted before YTX treatment.

Relative toxicity of dinophysistoxin-2 (DTX-2) compared with okadaic acid, based on acute intraperitoneal toxicity in mice.

When substituting the mouse bioassay for lipophilic marine algal toxins in shellfish with analytical methods, science based factors of relative toxicity for all analogues that contribute to health risk to consumers are necessary. The aim of this paper is to establish the relative intraperitoneal toxicity of dinophysistoxin-2 (DTX-2) compared with okadaic acid (OA). The study was performed as an open, randomised parallel group trial with a four level response surface design within each of the two parallels.

Discovery of fatty acid ester metabolites of spirolide toxins in mussels from Norway using liquid chromatography/tandem mass spectrometry.

Cultured mussels sampled in the spring of 2002 and 2003 from Skjer, a location in the Sognefjord, Norway, tested positive in the mouse bioassay for lipophilic toxins. In a previous report, it was established that a number of spirolides, cyclic imine toxins produced by the phytoplankton Alexandrium ostenfeldii, were present in the mussels and were responsible for the observed toxicity. The main toxin proved to be a new compound named 20-methyl spirolide G.

Comparison of ELISA and LC-MS analyses for yessotoxins in blue mussels (Mytilus edulis).

Blue mussels (Mytilus edulis) collected from Flødevigen Bay, Norway, in 2001 and 2002 were analysed for yessotoxins (YTXs) by ELISA and yessotoxin (YTX), 45-hydroxyYTX, and carboxyYTX by LC-MS. Results from the two methods were compared to evaluate the ELISA. The response in the ELISA was 3-13 times higher than LC-MS, probably due to the antibodies binding to other YTX analogues not included in the LC-MS analysis.