| ‘Aquamax’ has developed innovative food safety toxicity tests by identifying and characterising signature effects of key toxicants in fish: Built on the hypothesis that the effects of chemicals on an organism start with the interaction between a chemical and one or several biomolecules, the assumption was made that each interaction changes the production of proteins and that toxic chemicals with a similar mechanism of action have similar gene (mRNA) and protein expression profiles. To test this assumption, mice were fed salmon-based diets spiked with model toxicants. Different toxicants fed at high doses generated unique mRNA and protein expression profiles. However, in mice fed daily salmon containing environmentally-realistic concentrations of single toxicants, few effects on gene expression occurred. |  |
‘Aquamax’ has elucidated actions of keytoxicants and their amelioration by fish nutrients in developing mice andcultured mouse cells:
The expression ofthousands of genes (mRNA) and proteins in mouse brains and cultured mouse braincells were measured alongside pathological indices in tissues, changes inhormone levels, and neurodevelopment. ‘Aquamax’ studies focused primarily onthe effects of MeHg and the emerging group of brominated flame retardants.
High concentrations of MeHg causedoxidative damage in specific brain cells but more diverse effects included thedisturbance of immune proteins and evidence of competition for zinc inproteins.
Brominated flame retardants showedrelated effects on the brain, notably in disturbances of calcium and thyroidhormone signalling, protein unfolding and the activation of neuro-degenerativepathways. In mice, environmentally-realistic concentrations of brominated flameretardants caused subtle changes in tissues and hormone levels when the animalswere fed contaminated fish every day for four weeks. The brominated flameretardant, BDE47 accumulated in the brains of maternally-exposed offspring,reflecting maternal intake. Accumulationof BDE47 was significantly lower in offspring from dams fed a fish-based feedcompared to a casein-based feed. A few early reflexes were significantlyimpaired by exposure to BDE47 and better nutrition did not improve behaviouraltests. Few effects were observed on neurodevelopment in mouse pups of dams feddiets containing MeHg.
Many nutrients in seafood may counteracteffects of environmental pollutants. In the experiments on mice and culturedcells, both selenium and Ω-3 fatty acids protected against MeHg toxicity. Ω-3fatty acids also protected against toxic effects of the brominatedflame-retardant, HBCD, commonly found in oily fish.Therefore, the protective effects of nutrients in fish must be balanced withthe risk of consuming toxicants in fish.
‘Aquamax’ has conducted food safety testsin animals fed fish farmed on traditional and new feeds.
Several genetic,physiological and morphometric biomarkers have been identified, which aresymptomatic of exposure to groups of environmental contaminants commonly foundin fish. In all previous studies, exposures involved addition of singletoxicants to a salmon-based diet. In the final study of ‘Aquamax’, mice fed forfour weeks on feeds made from heavily contaminated Baltic salmon, ‘traditional’farmed salmon and salmon produced with ‘Aquamax’ technology, are being analysedfor detectable effects.
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