title: Generation and dietary modulation of anti-inflammatory electrophilic omega-3 fatty acid derivatives.
abstract: Dietary ω-3 polyunsaturated fatty acids (PUFAs) decrease cardiovascular risk via suppression of inflammation. The generation of electrophilic α,β-unsaturated ketone derivatives of the ω-3 PUFAs docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA) in activated human macrophages is catalyzed by cyclooxygenase-2 (Cox-2). These derivatives are potent pleiotropic anti-inflammatory signaling mediators that act via mechanisms including the activation of Nrf2-dependent phase 2 gene expression and suppression of pro-inflammatory NF-κB-driven gene expression. Herein, the endogenous generation of ω-3 PUFAs electrophilic ketone derivatives and their hydroxy precursors was evaluated in human neutrophils. In addition, their dietary modulation was assessed through a randomized clinical trial.
  
  
  METHODS
  Endogenous generation of electrophilic omega-3 PUFAs and their hydroxy precursors was evaluated by mass spectrometry in neutrophils isolated from healthy subjects, both at baseline and upon stimulation with calcium ionophore. For the clinical trial, participants were healthy adults 30-55 years of age with a reported EPA+DHA consumption of ≤300 mg/day randomly assigned to parallel groups receiving daily oil capsule supplements for a period of 4 months containing either 1.4 g of EPA+DHA (active condition, n = 24) or identical appearing soybean oil (control condition, n = 21). Participants and laboratory technicians remained blinded to treatment assignments.
  
  
  RESULTS
  5-lypoxygenase-dependent endogenous generation of 7-oxo-DHA, 7-oxo-DPA and 5-oxo-EPA and their hydroxy precursors is reported in human neutrophils stimulated with calcium ionophore and phorbol 12-myristate 13-acetate (PMA). Dietary EPA+DHA supplementation significantly increased the formation of 7-oxo-DHA and 5-oxo-EPA, with no significant modulation of arachidonic acid (AA) metabolite levels.
  
  
  CONCLUSIONS
  The endogenous detection of these electrophilic ω-3 fatty acid ketone derivatives supports the precept that the benefit of ω-3 PUFA-rich diets can be attributed to the generation of electrophilic oxygenated metabolites that transduce anti-inflammatory actions rather than the suppression of pro-inflammatory AA metabolites.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT00663871.
authors.affiliation: Fondazione Ri.Med, Palermo, Italy; Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Chiara
authors.initials: C
authors.lastname: Cipollina
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Sonia R
authors.initials: SR
authors.lastname: Salvatore
authors.affiliation: Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh Pennsylvania, United States of America.
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Muldoon
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Freeman
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Schopfer
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism; D004032:Diet; D004305:Dose-Response Relationship, Drug; D015525:Fatty Acids, Omega-3 / Q000096:biosynthesis* / Q000737:chemistry / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007659:Ketones / Q000737:chemistry; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D015525:Fatty Acids, Omega-3; D007659:Ketones; D001094:Arachidonate 5-Lipoxygenase
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