Mycotoxin uptake and metabolistation in Atlantic salmon
The increasing use of plant ingredients in salmon feeds introduce new
contaminants such as mycotoxins which normally are not associated with salmon
culture. Special concern for fish health and food safety has been risen for “novel” mycotoxins such beauvericin (BEA) and enniatins (ENN), little is known on the uptake and potential metabolisation of these mycotoxins in farmed marine fish.
This study aims to assess in which extend Atlantic salmon can absorb and metabolized dietary ENN and BEAU, as well as which phase I, II, and III metabolism systems are activated. Individual Atlantic salmon post smolts are anaesthetized (benzocaine) and force fed with a single force feed dose with BEA or ENN. Following force feeding (lasting approximately30 seconds from start anesthesia) fish will be put back to their holding tanks and kept for 24 hours under normal conditions before terminal sampling with an overdose of benzocaine and samples will be taken.
The single doses used are not expected to give harmful effects to the fish, but would be sufficient allow to study uptake and metabolisation metabolisms. Earlier single-force feeding trials on Atlantic salmon by us (Amlund and Berntssen, 2004, Comp. Biochem. Physiol. C, 138, 4, 507-511; DeGelder and Berntssen et al. 2016 Comp. Biochem. Physiol. C,185-186, 65-67) showed that after anesthesia, the fish recovered quickly (no mortalities), had no regurgitation was observed, and resumed normal feeding behavior. This indicates that the force feeding has little detrimental effect on the gastro-intestinal tract and that the anesthesia reduced discomfort during force feeding.
The present trial will give information on the ability of a marine fish to metabolize a mycotoxins that is present in novel plant based feeds. The degree of metabolization will determine the potential of the mycotoxin to accumulate in the farmed fish and hence its potence to become a feed or food safety issue. The single ENN and Beau dose will be given to pre smolt Atlantic salmon (salmo salar) (100-200 gr) at two levels, giving 5 treatments (control, 2 levels of ENN and BEAU) with 7 fish per treatment (total 35 fish). Samples will be taken to assess which Phase I, II, or III metabolism are activated (e.g. gene expression) and to total assessment of the parent compound and their metabolites (QTOF-vion MS/MS) in liver and bile will indicate the degree of metabolisation of the given single dose.
The use of single dose studies allows to give an exact dose to the fish and the use of individual fish as replicates in a feeding trial (e.g. 7 fish per treatment). In a normal feeding study in which an exact dose per group is assesses, replicate feeding groups (e.g. 3 tanks) are needed per treatment, with at least 15 fish per tank= 225 fish. Hence force feeding itself gives a refinement and reduction in number of animals needed.
contaminants such as mycotoxins which normally are not associated with salmon
culture. Special concern for fish health and food safety has been risen for “novel” mycotoxins such beauvericin (BEA) and enniatins (ENN), little is known on the uptake and potential metabolisation of these mycotoxins in farmed marine fish.
This study aims to assess in which extend Atlantic salmon can absorb and metabolized dietary ENN and BEAU, as well as which phase I, II, and III metabolism systems are activated. Individual Atlantic salmon post smolts are anaesthetized (benzocaine) and force fed with a single force feed dose with BEA or ENN. Following force feeding (lasting approximately30 seconds from start anesthesia) fish will be put back to their holding tanks and kept for 24 hours under normal conditions before terminal sampling with an overdose of benzocaine and samples will be taken.
The single doses used are not expected to give harmful effects to the fish, but would be sufficient allow to study uptake and metabolisation metabolisms. Earlier single-force feeding trials on Atlantic salmon by us (Amlund and Berntssen, 2004, Comp. Biochem. Physiol. C, 138, 4, 507-511; DeGelder and Berntssen et al. 2016 Comp. Biochem. Physiol. C,185-186, 65-67) showed that after anesthesia, the fish recovered quickly (no mortalities), had no regurgitation was observed, and resumed normal feeding behavior. This indicates that the force feeding has little detrimental effect on the gastro-intestinal tract and that the anesthesia reduced discomfort during force feeding.
The present trial will give information on the ability of a marine fish to metabolize a mycotoxins that is present in novel plant based feeds. The degree of metabolization will determine the potential of the mycotoxin to accumulate in the farmed fish and hence its potence to become a feed or food safety issue. The single ENN and Beau dose will be given to pre smolt Atlantic salmon (salmo salar) (100-200 gr) at two levels, giving 5 treatments (control, 2 levels of ENN and BEAU) with 7 fish per treatment (total 35 fish). Samples will be taken to assess which Phase I, II, or III metabolism are activated (e.g. gene expression) and to total assessment of the parent compound and their metabolites (QTOF-vion MS/MS) in liver and bile will indicate the degree of metabolisation of the given single dose.
The use of single dose studies allows to give an exact dose to the fish and the use of individual fish as replicates in a feeding trial (e.g. 7 fish per treatment). In a normal feeding study in which an exact dose per group is assesses, replicate feeding groups (e.g. 3 tanks) are needed per treatment, with at least 15 fish per tank= 225 fish. Hence force feeding itself gives a refinement and reduction in number of animals needed.