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Amritha Johny
Toxinology Research Group, Norwegian Veterinary Institute, 0454 Oslo, Norway

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Feed

Journal article
Published: 12 November 2020 in Genes
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Feed safety is a necessity for animal health and welfare as well as prerequisite for food safety and human health. Wheat gluten (WG) is considered as a valuable protein source in fish feed due to its suitability as a feed binder, high digestibility, good amino acid profile, energy density and most importantly, due to its relatively low level of anti-nutritional factors (ANFs). The main aim of this study was to identify the impact of dietary WG on salmon health by analysing growth, feed efficiency and the hepatic and intestinal transcriptomes. The fish were fed either control diet with fishmeal (FM) as the only source of protein or diets, where 15% or 30% of the FM were replaced by WG. The fish had a mean initial weight of 223 g and approximately doubled their weight during the 9-week experiment. Salmon fed on 30% WG showed reduced feed intake compared to the 15% and FM fed groups. The liver was the less affected organ but fat content and activities of the liver health markers in plasma increased with the inclusion level of WG in the diet. Gene expression analysis showed significant changes in both, intestine and liver of fish fed with 30% WG. Especially noticeable were changes in the lipid metabolism, in particular in relation to the intestinal lipoprotein transport and sterol metabolism. Moreover, the intestinal transcriptome of WG-fed fish showed shifts in the expression of a large number of genes responsible for immunity and tissue structure and integrity. These observations implied that the fish receiving WG-containing diet were undergoing nutritional stress. Overall, the study provided evidence that a high dietary level of WG can have a negative impact on the intestinal and liver health of salmon with symptoms similar to gluten sensitivity in humans.

ACS Style

Amritha Johny; Gerd Marit Berge; André S. Bogevik; Aleksei Krasnov; Bente Ruyter; Christiane Kruse Fæste; Tone-Kari Knutsdatter Østbye. Sensitivity to Dietary Wheat Gluten in Atlantic Salmon Indicated by Gene Expression Changes in Liver and Intestine. Genes 2020, 11, 1339 .

AMA Style

Amritha Johny, Gerd Marit Berge, André S. Bogevik, Aleksei Krasnov, Bente Ruyter, Christiane Kruse Fæste, Tone-Kari Knutsdatter Østbye. Sensitivity to Dietary Wheat Gluten in Atlantic Salmon Indicated by Gene Expression Changes in Liver and Intestine. Genes. 2020; 11 (11):1339.

Chicago/Turabian Style

Amritha Johny; Gerd Marit Berge; André S. Bogevik; Aleksei Krasnov; Bente Ruyter; Christiane Kruse Fæste; Tone-Kari Knutsdatter Østbye. 2020. "Sensitivity to Dietary Wheat Gluten in Atlantic Salmon Indicated by Gene Expression Changes in Liver and Intestine." Genes 11, no. 11: 1339.

Journal article
Published: 12 April 2020 in Ecotoxicology and Environmental Safety
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Efficient aquaculture is depending on sustainable protein sources. The shortage in marine raw materials has initiated a shift to “green aquafeeds” based on staple ingredients such as soy and wheat. Plant-based diets entail new challenges regarding fish health, product quality and consumer risks due to the possible presence of chemical contaminants, natural toxins and bioactive compounds like phytoestrogens. Daidzein (DAI), genistein (GEN) and glycitein (GLY) are major soy isoflavones with considerable estrogenic activities, potentially interfering with the piscine endocrine system and affecting consumers after carry-over. In this context, information on isoflavone biotransformation in fish is crucial for risk evaluation. We have therefore isolated hepatic fractions of Atlantic salmon (Salmo salar), the most important species in Norwegian aquaculture, and used them to study isoflavone elimination and metabolite formation. The salmon liver microsomes and primary hepatocytes were characterized with respect to phase I cytochrome P450 (CYP) and phase II uridine-diphosphate-glucuronosyltransferase (UGT) enzyme activities using specific probe substrates, which allowed comparison to results in other species. DAI, GEN and GLY were effectively cleared by UGT. Based on the measurement of exact masses, fragmentation patterns, and retention times in liquid chromatography high-resolution mass spectrometry, we preliminarily identified the 7-O-glucuronides as the main metabolites in salmon, possibly produced by UGT1A1 and UGT1A9-like activities. In contrast, the production of oxidative metabolites by CYP was insignificant. Under optimized assay conditions, only small amounts of mono-hydroxylated DAI were detectable. These findings suggested that bioaccumulation of phytoestrogens in farmed salmon and consumer risks from soy-containing aquafeeds are unlikely.

ACS Style

Amritha Johny; Lada Ivanova; Tone-Kari Knutsdatter Østbye; Christiane Kruse Fæste. Biotransformation of phytoestrogens from soy in enzymatically characterized liver microsomes and primary hepatocytes of Atlantic salmon. Ecotoxicology and Environmental Safety 2020, 197, 110611 .

AMA Style

Amritha Johny, Lada Ivanova, Tone-Kari Knutsdatter Østbye, Christiane Kruse Fæste. Biotransformation of phytoestrogens from soy in enzymatically characterized liver microsomes and primary hepatocytes of Atlantic salmon. Ecotoxicology and Environmental Safety. 2020; 197 ():110611.

Chicago/Turabian Style

Amritha Johny; Lada Ivanova; Tone-Kari Knutsdatter Østbye; Christiane Kruse Fæste. 2020. "Biotransformation of phytoestrogens from soy in enzymatically characterized liver microsomes and primary hepatocytes of Atlantic salmon." Ecotoxicology and Environmental Safety 197, no. : 110611.

Journal article
Published: 13 April 2019 in Toxins
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New protein sources in fish feed require the assessment of the carry-over potential of contaminants and anti-nutrients from feed ingredients into the fish, and the assessment of possible health risks for consumers. Presently, plant materials including wheat and legumes make up the largest part of aquafeeds, so evaluation of the transfer capabilities of typical toxic metabolites from plant-infesting fungi and of vegetable phytoestrogens into fish products is of great importance. With the aim of facilitating surveillance of relevant mycotoxins and isoflavones, we have developed and validated a multi-analyte LC-HRMS/MS method that can be used to ensure compliance to set maximum levels in feed and fish. The method performance characteristics were determined, showing high specificity for all 25 targeted analytes, which included 19 mycotoxins and three isoflavones and their corresponding aglycons with sufficient to excellent sensitivities and uniform analytical linearity in different matrices. Depending on the availability of matching stable isotope-labelled derivates or similar-structure homologues, calibration curves were generated either by using internal standards or by matrix-matched external standards. Precision and recovery data were in the accepted range, although they varied between the different analytes. This new method was considered as fit-for-purpose and applied for the analysis of customised fish feed containing wheat gluten, soy, or pea protein concentrate as well as salmon and zebrafish fed on diets with these ingredients for a period of up to eight weeks. Only mycotoxin enniatin B, at a level near the limit of detection, and low levels of isoflavones were detected in the feed, demonstrating the effectiveness of maximum level recommendations and modern feed processing technologies in the Norwegian aquaculture industry. Consequently, carry-over into fish muscle was not observed, confirming that fillets from plant-fed salmon were safe for human consumption.

ACS Style

Amritha Johny; Christiane Kruse Fæste; André S. Bogevik; Gerd Marit Berge; Jorge M.O. Fernandes; Lada Ivanova. Development and Validation of a Liquid Chromatography High-Resolution Mass Spectrometry Method for the Simultaneous Determination of Mycotoxins and Phytoestrogens in Plant-Based Fish Feed and Exposed Fish. Toxins 2019, 11, 222 .

AMA Style

Amritha Johny, Christiane Kruse Fæste, André S. Bogevik, Gerd Marit Berge, Jorge M.O. Fernandes, Lada Ivanova. Development and Validation of a Liquid Chromatography High-Resolution Mass Spectrometry Method for the Simultaneous Determination of Mycotoxins and Phytoestrogens in Plant-Based Fish Feed and Exposed Fish. Toxins. 2019; 11 (4):222.

Chicago/Turabian Style

Amritha Johny; Christiane Kruse Fæste; André S. Bogevik; Gerd Marit Berge; Jorge M.O. Fernandes; Lada Ivanova. 2019. "Development and Validation of a Liquid Chromatography High-Resolution Mass Spectrometry Method for the Simultaneous Determination of Mycotoxins and Phytoestrogens in Plant-Based Fish Feed and Exposed Fish." Toxins 11, no. 4: 222.