Animal bioassays: identification of toxins and mechanism of action *

Complex secondary metabolites, some of which ar highly toxic to mammals, are produced by some marine organisms. Some such organisms are important food sources for marine animals, and when ingested, the toxins that they contain may be absorbed and stored in the tissues of the predators, which may then become toxic to animals higher up in the food chain. In order to avoid harm to consumers of seafood, it is essential that the potential risk to human health of such substances is undertaken, so that appropriate regulatory limits may be set. Risk assessment comprises four stages: hazard identification, hazard characterisation, exposure assessment and risk characterisation. In most cases, risk is assessed through toxicological studies in animals, which must be based on appropriate techniques and routes of administration. The mechanism of toxicity of poisons is an important factor in hazard characterisation, and certain criteria must be met for the identification of such mechanisms. While considerable progress has been made in the risk assessment of seafood toxins through toxicological studies in animals, there are still gaps in our knowledge. * Title in final publication: Toxicology of seafood toxins: animal studies and mechanisms of action