title: Emodin inhibits LPS-induced inflammatory response by activating PPAR-γ in mouse mammary epithelial cells.
abstract: Emodin, an anthraquinone derivative isolated from the rhizomes of Rheum palmatum, has been reported to have a protective effect against lipopolysaccharide (LPS)-induced mastitis. However, the underlying molecular mechanisms are not well understood. The aim of this study was to investigate the molecular mechanisms of emodin in modifying lipopolysaccharide (LPS)-induced signaling pathways in mouse mammary epithelial cells (MEC). The pro-inflammatory cytokines were determined by ELISA. Nuclear factor-κB (NF-κB), inhibitory kappa B (IκBα) protein, p38, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and PPAR-γ were determined by Western blotting. The results showed that emodin suppressed tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), iNOS and COX-2 expression. We also found that emodin inhibited LPS-induced NF-κB activation, IκBα degradation, phosphorylation of ERK, JNK and P38. Furthermore, emodin could activate PPAR-γ and the anti-inflammatory effects of emodin can be reversed by GW9662, a specific antagonist for PPAR-γ. In conclusion, our results demonstrate that emodin activates PPAR-γ, thereby attenuating LPS-induced inflammatory response.
authors.affiliation: College of Veterinary Medicine, Jilin University, Changchun 130062, Jilin Province, PR China.
authors.forename: Zhengtao
authors.initials: Z
authors.lastname: Yang
authors.affiliation: College of Veterinary Medicine, Jilin University, Changchun 130062, Jilin Province, PR China.
authors.forename: Ershun
authors.initials: E
authors.lastname: Zhou
authors.affiliation: College of Veterinary Medicine, Jilin University, Changchun 130062, Jilin Province, PR China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wei
authors.affiliation: College of Veterinary Medicine, Jilin University, Changchun 130062, Jilin Province, PR China.
authors.forename: Depeng
authors.initials: D
authors.lastname: Li
authors.affiliation: College of Veterinary Medicine, Jilin University, Changchun 130062, Jilin Province, PR China.
authors.forename: Zhengkai
authors.initials: Z
authors.lastname: Wei
authors.affiliation: College of Veterinary Medicine, Jilin University, Changchun 130062, Jilin Province, PR China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Jilin University, Changchun 130062, Jilin Province, PR China. Electronic address: xczhang@jlu.edu.cn.
authors.forename: Xichen
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004642:Emodin / Q000494:pharmacology*; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D007249:Inflammation / Q000139:chemically induced* / Q000188:drug therapy* / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D008321:Mammary Glands, Animal / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D016328:NF-kappa B / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D047495:PPAR gamma / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D015850:Interleukin-6; D008070:Lipopolysaccharides; D016328:NF-kappa B; D047495:PPAR gamma; D014409:Tumor Necrosis Factor-alpha; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D004642:Emodin
keywords: Cytokines; Emodin; LPS; Mastitis; NF-κB; PPAR-γ