title: Omega-3 supplementation improves pancreatic islet redox status: in vivo and in vitro studies.
abstract: OBJECTIVE
  The aim of the study was to evaluate the potential changes induced by fish oil (FO) supplementation on the redox status of pancreatic islets from healthy rats. To test whether these effects were due to eicosapentaenoic acid and docosahexaenoic acid (ω-3), in vitro experiments were performed.
  
  
  METHODS
  Rats were supplemented with FO, and pancreatic islets were obtained. Islets were also treated in vitro with palmitate (P) or eicosapentaenoic acid + docosahexaenoic acid (ω-3). Insulin secretion (GSIS), glucose oxidation, protein expression, and superoxide content were analyzed.
  
  
  RESULTS
  The FO group showed a reduction in superoxide content. Moreover, FO reduced the expression of NAD(P)H oxidase subunits and increased superoxide dismutase, without altering β-cell function. Palmitate increased β-cell reactive oxygen species (ROS) production, apoptosis, and impaired GSIS. Under these conditions, ω-3 triggered a parallel reduction in ROS production and β-cell apoptosis induced by P and protected against the impairment in GSIS. There was no difference in mitochondrial ROS production.
  
  
  CONCLUSIONS
  Our results show that ω-3 protect pancreatic islets from alterations induced by P. In vivo FO supplementation modulates the redox state of pancreatic β-cell. Considering that in vitro effects do not involve mitochondrial superoxide production, we can speculate that this protection might involve NAD(P)H oxidase activity.
authors.affiliation: From the *Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo; and †Department of Physiology Sciences, University of Londrina, Londrina, Paraná, Brazil.
authors.forename: Camila F
authors.initials: CF
authors.lastname: Lucena
authors.forename: Leticia P
authors.initials: LP
authors.lastname: Roma
authors.forename: Maria Fernanda R
authors.initials: MF
authors.lastname: Graciano
authors.forename: Katherine
authors.initials: K
authors.lastname: Veras
authors.forename: Daniel
authors.initials: D
authors.lastname: Simões
authors.forename: Rui
authors.initials: R
authors.lastname: Curi
authors.forename: Angelo R
authors.initials: AR
authors.lastname: Carpinelli
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D017209:Apoptosis / Q000187:drug effects; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000008:administration & dosage*; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage*; D005978:Glutathione / Q000378:metabolism; D007328:Insulin / Q000097:blood; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D019255:NADPH Oxidases / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D019308:Palmitic Acid / Q000633:toxicity; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors; D046509:Tissue Culture Techniques
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D017382:Reactive Oxygen Species; D013481:Superoxides; D004281:Docosahexaenoic Acids; D019308:Palmitic Acid; D015118:Eicosapentaenoic Acid; D013482:Superoxide Dismutase; D019255:NADPH Oxidases; D005978:Glutathione