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Published on: March 10, 2015
Comparison of oral and intraperitoneal toxicity of yessotoxin towards mice
1Department of Pharmacology, Microbiology and Food Hygiene, Norwegian School of Veterinary Science, PO Box 8146, Dep., 0033, Oslo, Norway. tore.aune@veths.no
Abstract:
Currently, yessotoxin is regulated among the toxins in the diarrhetic shellfish poisoning (DSP) complex. Yessotoxin is equally acutely toxic towards mice upon intraperitoneal injections as those algal toxins giving diarrhea, but is not diarrheagenic. Its presence in mussels may therefore lead to overestimation of risk of DSP in consumers when the standard mouse bioassay is used. Arguments are presented for the use of analytical methods instead of the mouse bioassay for the diarrheagenic DSP toxins and yessotoxin. Yessotoxin was found to be more than ten times less toxic to mice via the oral route, compared with intraperitoneal injections. Even at 10mg/kg body weight, the highest dose ever tested orally, yessotoxin did not kill the mice. By means of light microscopy of several organs, moderate changes were only observed in the heart. Ultrastructural studies revealed swelling of heart muscle cells leading to separation of the organelles. Effects were most pronounced close to the capillaries. The pathological changes were clearly dose dependent, and the lowest oral dose where any effects were seen was 2.5mg yessotoxin per kg.
Insights
Yessotoxin, a toxin in the diarrhetic shellfish poisoning complex, is not diarrheagenic but shows acute toxicity in mice. Analytical methods are recommended over mouse bioassays to avoid overestimating risks from yessotoxin in shellfish.
Area of Science:
- Marine Toxinology
- Ecotoxicology
- Food Safety
Background:
- Yessotoxin is regulated as part of the diarrhetic shellfish poisoning (DSP) complex.
- Yessotoxin exhibits acute toxicity in mice but lacks diarrheagenic properties.
- Current reliance on mouse bioassays may overestimate DSP risks due to yessotoxin's presence.
Purpose of the Study:
- To evaluate the oral toxicity and pathological effects of yessotoxin.
- To advocate for analytical methods over mouse bioassays for DSP toxin detection.
Main Methods:
- Oral administration of yessotoxin to mice at varying doses.
- Light and ultrastructural microscopy of mouse organs, focusing on the heart.
- Dose-response assessment of observed pathological changes.
Main Results:
- Yessotoxin is significantly less toxic orally than via intraperitoneal injection.
- No mortality observed even at the highest oral dose (10 mg/kg).
- Dose-dependent moderate cardiac changes, including myocyte swelling, observed at oral doses as low as 2.5 mg/kg.
Conclusions:
- Yessotoxin's oral toxicity profile differs significantly from intraperitoneal toxicity.
- Mouse bioassays may misrepresent the risk of yessotoxin in shellfish consumption.
- Analytical detection methods are preferable for accurate risk assessment of yessotoxin and DSP toxins.
