title: Effect of in vitro digested cod liver oil of different quality on oxidative, proteomic and inflammatory responses in the yeast Saccharomyces cerevisiae and human monocyte-derived dendritic cells.
abstract: BACKGROUND
  Upon oxidation of the polyunsaturated fatty acids in fish oil, either before ingestion or, as recently shown, during the gastro-intestinal passage, a cascade of potentially cytotoxic peroxidation products, such as malondialdehyde and 4-hydroxy-2-hexenal, can form. In this study, we digested fresh and oxidised cod liver oils in vitro, monitored the levels of lipid peroxidation products and evaluated oxidative, proteomic and inflammatory responses to the two types of digests in the yeast Saccharomyces cerevisiae and human monocyte-derived dendritic cells.
  
  
  RESULTS
  Digests of cod liver oil with 22-53 µmol L(-1) malondialdehyde and 0.26-3.7 µmol L(-1) 4-hydroxy-2-hexenal increased intracellular oxidation and cell energy metabolic activity compared to a digested blank in yeast cells and the influence of digests on mitochondrial protein expression was more pronounced for oxidised cod liver oil than fresh cod liver oil. The four differentially expressed and identified proteins were related to energy metabolism and oxidative stress response. Maturation of dendritic cells was affected in the presence of digested fresh cod liver oil compared to the digested blank, measured as lower CD86 expression. The ratio of secreted cytokines, IL-12p40/IL-10, suggested a pro-inflammatory effect of the digested oils in relation to the blank (1.47-1.67 vs. 1.07).
  
  
  CONCLUSIONS
  Gastro-intestinal digestion of cod liver oil increases the amount of oxidation products and resulting digests affect oxidation in yeast and immunomodulation of dendritic cells.
authors.affiliation: Food Science, Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Larsson
authors.affiliation: Biotechnical Faculty, Department of Food Science and Technology, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Katja
authors.initials: K
authors.lastname: Istenič
authors.affiliation: National Food Institute, Technical University of Denmark, Lyngby, Denmark.
authors.forename: Tune
authors.initials: T
authors.lastname: Wulff
authors.affiliation: Matís ohf., Reykjavik, Iceland.
authors.forename: Rósa
authors.initials: R
authors.lastname: Jónsdóttir
authors.affiliation: Matís ohf., Reykjavik, Iceland.
authors.forename: Hordur
authors.initials: H
authors.lastname: Kristinsson
authors.affiliation: Department of Immunology and Centre for Rheumatology Research, Landspitali, The National University Hospital of Iceland, Reykjavik, Iceland.|Faculty of Medicine, Biomedical Center, University of Iceland, Reykjavik, Iceland.
authors.forename: Jona
authors.initials: J
authors.lastname: Freysdottir
authors.affiliation: Food Science, Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Undeland
authors.affiliation: Biotechnical Faculty, Department of Food Science and Technology, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Polona
authors.initials: P
authors.lastname: Jamnik
mesh_terms: D000447:Aldehydes / Q000378:metabolism; D002454:Cell Differentiation; D003060:Cod Liver Oil / Q000378:metabolism / Q000494:pharmacology*; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000187:drug effects*; D004063:Digestion; D004734:Energy Metabolism / Q000187:drug effects*; D006801:Humans; D007249:Inflammation / Q000209:etiology* / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000378:metabolism; D009000:Monocytes / Q000187:drug effects; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics; D012441:Saccharomyces cerevisiae / Q000187:drug effects*
chemical_list: D000447:Aldehydes; D016207:Cytokines; D024101:Mitochondrial Proteins; D020543:Proteome; C045934:4-hydroxy-2-hexenal; D008315:Malondialdehyde; D003060:Cod Liver Oil
keywords: cod liver oil; digestion; immunomodulation; oxidation; yeast