title: Celecoxib, a COX-2 inhibitor, synergistically potentiates the anti-inflammatory activity of docosahexaenoic acid in macrophage cell line.
abstract: BACKGROUND
  The anti-inflammatory properties of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and non-steroidal anti-inflammatory drugs overlap in many ways. The aim of this study was to examine the individual and synergetic anti-inflammatory effects of celecoxib, EPA and DHA in RAW-264.7 cell line.
  
  
  METHODS
  The cells were exposed to EPA, DHA, celecoxib, rosiglitazone, GW9662 alone or their combination, and stimulated with 5 μg/mL lipopolysaccharide (LPS). Nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and prostaglandin-E2 (PGE2) levels were estimated in the medium using enzyme-linked immunosorbent assays. The cyclooxygenase-2 (COX-2) and inducible Nitric Oxide Synthase (iNOS) expression were analyzed in the cell lysate by immunoblotting. Peroxisome proliferator-activated receptor γ (PPARγ) and nuclear factor-κB (NF-κB) transcription factor activation assays were performed in the nuclear extract.
  
  
  RESULTS
  Combined treatment of DHA (50 μM) and celecoxib (20 μM) significantly inhibited LPS induced synthesis of NO, TNF-α, IL-6 and PGE2 levels in the cells, compared to the individual treatments. In addition, DHA and celecoxib diminished the COX-2 and iNOS expression in the cells. This was associated with increased PPARγ activity, supressed NF-κB activity in the nucleus. We determined whether GW9662, a specific PPARγ inhibitor, could abolish the anti-inflammatory effect of DHA and celecoxib. GW9662 has abolished the DHA and celecoxib induced PPARγ activation, but did not alter the NF-κB mediated anti-inflammatory effects induced by celecoxib and DHA. Interestingly, EPA did not exhibit any inhibitory effect on these parameters.
  
  
  CONCLUSIONS
  Our results suggest that DHA and celecoxib exhibit anti-inflammatory effect through inhibition of NF-κB, independent of PPARγ. Co-administration of celecoxib and DHA would be promising approach for the treatment of inflammatory diseases.
authors.affiliation: a Biochemistry and Nutrition Department , Lab-115, CSIR - Central Food Technological Research Institute (CFTRI) , Mysuru , Karnataka , India.
authors.forename: Vijay Kumar Reddy
authors.initials: VK
authors.lastname: Kondreddy
authors.affiliation: a Biochemistry and Nutrition Department , Lab-115, CSIR - Central Food Technological Research Institute (CFTRI) , Mysuru , Karnataka , India.
authors.forename: Akhilender Naidu
authors.initials: AN
authors.lastname: Kamatham
mesh_terms: D000818:Animals; D000068579:Celecoxib / Q000819:agonists / Q000494:pharmacology*; D002460:Cell Line; D051546:Cyclooxygenase 2 / Q000096:biosynthesis*; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology*; D015232:Dinoprostone / Q000096:biosynthesis; D004281:Docosahexaenoic Acids / Q000819:agonists / Q000494:pharmacology*; D004357:Drug Synergism; D007249:Inflammation / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D015850:Interleukin-6 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000633:toxicity; D008264:Macrophages / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D009569:Nitric Oxide / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D015850:Interleukin-6; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D004281:Docosahexaenoic Acids; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; D000068579:Celecoxib; D015232:Dinoprostone
keywords: Celecoxib; DHA; EPA; TNF-α; inflammation