Tissue distribution and elimination of deoxynivalenol and ochratoxin A in dietary-exposed Atlantic salmon (Salmo salar)

Abstract

Post-smolt Atlantic salmon (Salmo salar) were fed standard feed with added 2 or 6 mg kg -1 pure deoxynivalenol (DON), 0.8 or 2.4 mg kg -1 pure ochratoxin A (OTA), or no added toxins for up to 8 weeks. The experiments were performed in duplicate tanks with 25 fish each per diet group, and the feed was given for three 2-h periods per day. After 3, 6 and 8 weeks, 10 fish from each diet group were sampled. In the following hours after the last feeding at 8 weeks, toxin elimination was studied by sampling three fish per diet group at five time points. Analysis of DON and OTA in fish tissues and plasma was conducted by liquid chromatography-mass spectrometry and high-pressure liquid chromatography with fluorescence detection, respectively. DON was distributed to the liver, kidney, plasma, muscle, skin and brain, and the concentrations in liver and muscle increased significantly from 3 to 8 weeks of exposure to the high-DON diet. After the last feeding at 8 weeks, DON concentration in liver reached a maximum at 1 h and decreased thereafter with a half-life (t 1/2 ) of 6.2 h. DON concentration in muscle reached a maximum at 6 h and was then eliminated with a t 1/2 = 16.5 h. OTA was mainly found in liver and kidney, and the concentration in liver decreased significantly from 3 to 8 weeks in the high-OTA group. OTA was eliminated faster than DON from various tissues. By using Norwegian food consumption data and kinetic findings in this study, we predicted the human exposure to DON and OTA from fish products through carryover from the feed. Following a comparison with tolerable daily intakes, we found the risk to human health from the consumption of salmon-fed diets containing maximum recommended levels of these toxins to be negligible. ARTICLE HISTORY

Mycotoxins in aquaculture: feed and food

“…While Bernhoft et al . () proved the possibility of DON deposition in the liver and muscle in a relatively short exposure period (3 weeks) with high DON levels (2,000 and 6,000 μg kg −1 DON), Nácher‐Mestre et al . () showed no carry over effects of FUM and DON co‐contamination at low levels during long exposure periods.…”

“…In Atlantic salmon (Bernhoft et al . ), it would appears that OTA is rapidly eliminated. Its deposition in tissues was only shown in liver (4.81 μg kg −1 ) and only at the highest OTA intake level (2,400 μg kg −1 ).…”

“…The most comprehensive study was carried out by Bernhoft et al . () in Atlantic salmon ( S. salar ). Bernhoft et al .…”

“…Bernhoft et al . () fed salmon with 2,000 and 6,000 μg kg −1 DON over the course of 8 weeks and sampling liver, muscle, kidney and skin at 3, 6 and 8 weeks. The authors observed that both exposure dosages (2,000 and 6,000 μg kg −1 DON) led to DON deposition in the liver and muscle at all sampling points, except for the higher dosage at the last sampling point (8 weeks), at which DON was found in all sampled tissues (Table ).…”

Report from the 1st MYCOKEY International Conference Global Mycotoxin Reduction in the Food and Feed Chain Held in Ghent, Belgium, 11–14 September 2017

“…ENNB1 and DON belong to the most prevalent fungal derivatives in grain in temperate climate zones and have been detected in the liver and edible muscle of different fish from aquaculture (Tolosa et al, 2014;Bernhoft et al, 2017). The microsomal assay conditions were optimised by using different mycotoxin concentrations and incubation times, with the aim of either maximum metabolite production or linear kinetics of ENNB1 and DON depletion.…”