title: DHA suppresses Prevotella intermedia lipopolysaccharide-induced production of proinflammatory mediators in murine macrophages.
abstract: Several reports have indicated that dietary intake of DHA is associated with lower prevalence of periodontitis. In the present study, we investigated the effect of DHA on the production of proinflammatory mediators in murine macrophage-like RAW264.7 cells stimulated with lipopolysaccharide (LPS) isolated from Prevotella intermedia, a pathogen implicated in inflammatory periodontal disease, and its mechanisms of action. LPS was isolated from lyophilised P. intermedia ATCC 25,611 cells using the standard hot-phenol-water protocol. Culture supernatants were collected and assayed for NO, IL-1β and IL-6. Real-time PCR analysis was carried out to detect the expression of inducible NO synthase (iNOS), IL-1β, IL-6 and haeme oxygenase-1 (HO-1) mRNA. Immunoblot analysis was carried out to quantify the expression of iNOS and HO-1 protein and concentrations of signalling proteins. DNA-binding activities of NF-κB subunits were determined using an ELISA-based assay kit. DHA significantly attenuated the production of NO, IL-1β and IL-6 at both gene transcription and translation levels in P. intermedia LPS-activated RAW264.7 cells. DHA induced the expression of HO-1 in cells treated with P. intermedia LPS. Selective inhibition of HO-1 activity by tin protoporphyrin IX significantly mitigated the inhibitory effects of DHA on LPS-induced NO production. DHA significantly attenuated the phosphorylation of c-Jun N-terminal kinase induced by LPS. In addition, DHA suppressed the transcriptional activity of NF-κB by regulating the nuclear translocation and DNA-binding activity of NF-κB p50 subunit and inhibited the phosphorylation of signal transducer and activator of transcription 1. Further in vivo studies are needed to better evaluate the potential of DHA in humans as a therapeutic agent to treat periodontal disease.
authors.affiliation: Department of Biological Science, College of Medical and Life Sciences, Silla University, 140 Baegyang-daero, 700beon-gil, Sasang-gu, Busan 617-736, Korea.
authors.forename: Eun-Young
authors.initials: EY
authors.lastname: Choi
authors.affiliation: Department of Biological Science, College of Medical and Life Sciences, Silla University, 140 Baegyang-daero, 700beon-gil, Sasang-gu, Busan 617-736, Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Jin
authors.affiliation: Department of Periodontology, School of Dentistry, Pusan National University, 49 Busandaehak-ro, Mulgeum-eup, Yangsan, Gyeongsangnam-do 626-870, Korea.
authors.forename: Jeom-Il
authors.initials: JI
authors.lastname: Choi
authors.affiliation: Department of Biological Science, College of Medical and Life Sciences, Silla University, 140 Baegyang-daero, 700beon-gil, Sasang-gu, Busan 617-736, Korea.
authors.forename: In Soon
authors.initials: IS
authors.lastname: Choi
authors.affiliation: Department of Periodontology, School of Dentistry, Pusan National University, 49 Busandaehak-ro, Mulgeum-eup, Yangsan, Gyeongsangnam-do 626-870, Korea.
authors.forename: Sung-Jo
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002461:Cell Line, Transformed; D004041:Dietary Fats / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004281:Docosahexaenoic Acids / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D051547:Heme Oxygenase-1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D018836:Inflammation Mediators / Q000037:antagonists & inhibitors* / Q000378:metabolism; D053583:Interleukin-1beta / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors* / Q000302:isolation & purification / Q000633:toxicity; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D008565:Membrane Proteins / Q000819:agonists / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D008665:Metalloporphyrins / Q000494:pharmacology; D051379:Mice; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D010518:Periodontitis / Q000276:immunology / Q000378:metabolism / Q000382:microbiology / Q000517:prevention & control; D018713:Prevotella intermedia / Q000378:metabolism*; D011524:Protoporphyrins / Q000494:pharmacology; D000093242:Interleukin-6 Inhibitors
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004041:Dietary Fats; D004281:Docosahexaenoic Acids; D004791:Enzyme Inhibitors; D051547:Heme Oxygenase-1; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D015850:Interleukin-6; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D008665:Metalloporphyrins; D016328:NF-kappa B; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; D011524:Protoporphyrins; D000093242:Interleukin-6 Inhibitors; C587672:IL1B protein, mouse; C577686:interleukin-6, mouse; C032628:tin protoporphyrin IX; C496317:Nos2 protein, mouse; C496542:Hmox1 protein, mouse