Bioavailability profiling shows differences in OA, DTX1 and DTX2 toxins that justify their toxicity

Area of Science:

• Marine Biology
• Toxicology
• Food Safety

Background:

• Marine toxins, specifically Okadaic acid (OA) group compounds, are produced by dinoflagellates and accumulate in seafood, posing a global health risk.
• These toxins are the causative agents of Diarrhetic Shellfish Poisoning (DSP) in humans, also known as Diarrhetic Shellfish Toxins (DSTs).

Purpose of the Study:

• To investigate the symptoms, toxicity, absorption, distribution, and elimination of OA, Dinophysistoxin-1 (DTX1), and Dinophysistoxin-2 (DTX2).
• To evaluate these effects at a sublethal dose (90 μg toxin/kg body weight) administered via voluntary feeding in mice.

Main Methods:

• Sublethal doses of OA, DTX1, and DTX2 were administered to mice through voluntary feeding.
• Symptoms, toxin distribution within organs, excretion routes, and elimination rates were monitored.
• Macroscopic damage in gastrointestinal organs was assessed post-administration.

Main Results:

• OA and DTX1 induced more severe symptoms, notably diarrhea, compared to DTX2.
• Toxins were distributed throughout the organism, with detectable levels in the liver, kidney, stomach, small intestine, and large intestine.
• Fecal excretion was predominant; OA showed rapid elimination, while DTX2 exhibited prolonged excretion.
• Macroscopic damage to the stomach and intestines was observed, persisting up to 120 hours.

Conclusions:

• Sublethal doses of Diarrhetic Shellfish Toxins (DSTs) significantly impact organismal pharmacokinetics, leading to observable toxicity and gastrointestinal damage.
• Understanding the absorption, distribution, and elimination of these toxins is critical for assessing public health risks associated with contaminated seafood.
• The differential excretion rates of OA and DTX2 highlight the need for specific monitoring and risk management strategies.