title: Enhanced anti-inflammatory effects of DHA and quercetin in lipopolysaccharide-induced RAW264.7 macrophages by inhibiting NF-κB and MAPK activation.
abstract: The aim of the present study was to investigate the anti-inflammatory effects of docosahexaenoic acid (DHA) + quercetin (QE) used in combination. DHA and QE are natural compounds derived from various foods and have been demonstrated to exert anti‑inflammatory effects The protein mRNA expression involved in the nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) signalling pathway was analyzed by western blot analysis and reverse transcription-polymerase chain reaction methods respectively, other cytokines were detected by an enzyme‑linked immunosorbent assay kit. The results of the present study demonstrated that combined treatment of lipopolysaccharide (LPS)‑stimulated RAW264.7 cells with DHA + QE decreased the levels of pro‑inflammatory mediators to a greater extent than QE or DHA alone. Additionally, DHA + QE synergistically suppressed nitric oxide, prostaglandin E2 and cyclooxygenase-2 levels. Molecular‑level studies indicated that the DHA + QE combination can significantly inhibit the mRNA expression of NF‑κB subunits p50 and p65, extracellular signal‑regulated kinase (ERK) 1/2 and c‑JUN N‑terminal kinase (JNK) 1/2, which suggests that the NF‑κB signalling pathway is involved in the synergistic effects observed. Furthermore, western blot analysis demonstrated that DHA + QE synergistically inhibit the phosphorylation of p50, p65, ERK1/2 and JNK1/2. This finding indicates that the enhanced anti‑inflammatory effects of the combined compounds are achieved by suppressing NF‑κB and MAPK signalling in LPS‑stimulated RAW264.7 cells. The results of the present study suggest that DHA and QE in combination may be utilized as potent anti‑inflammatory compounds, with potential preventative or palliative effects on obesity, atherosclerosis and cardiovascular diseases.
authors.affiliation: College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R. China.
authors.forename: Tian-Lei
authors.initials: TL
authors.lastname: Si
authors.affiliation: College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R. China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Liu
authors.affiliation: National Engineering Research Center For Wheaten Food, Henan Xingtai S&T Industry Co., Ltd., Zhengzhou, Henan 450007, P.R. China.
authors.forename: Yu-Fei
authors.initials: YF
authors.lastname: Ren
authors.affiliation: College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R. China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R. China.
authors.forename: Xiao-Yun
authors.initials: XY
authors.lastname: Xu
authors.affiliation: College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R. China.
authors.forename: Er-Hu
authors.initials: EH
authors.lastname: Li
authors.affiliation: College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R. China.
authors.forename: Si-Yi
authors.initials: SY
authors.lastname: Pan
authors.affiliation: College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R. China.
authors.forename: Jiu-Liang
authors.initials: JL
authors.lastname: Zhang
authors.affiliation: College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R. China.
authors.forename: Ke-Xing
authors.initials: KX
authors.lastname: Wang
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology* / Q000633:toxicity; D015415:Biomarkers; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism; D004281:Docosahexaenoic Acids / Q000494:pharmacology* / Q000633:toxicity; D005786:Gene Expression Regulation / Q000187:drug effects; D018836:Inflammation Mediators / Q000378:metabolism; D008070:Lipopolysaccharides / Q000276:immunology; D008262:Macrophage Activation / Q000187:drug effects / Q000276:immunology; D008264:Macrophages / Q000187:drug effects* / Q000502:physiology*; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D011794:Quercetin / Q000494:pharmacology* / Q000633:toxicity; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000893:Anti-Inflammatory Agents; D015415:Biomarkers; D016207:Cytokines; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D016328:NF-kappa B; D004281:Docosahexaenoic Acids; D009569:Nitric Oxide; D011794:Quercetin; D052247:Nitric Oxide Synthase Type II; D020928:Mitogen-Activated Protein Kinases