title: Isotrifoliol inhibits pro-inflammatory mediators by suppression of TLR/NF-κB and TLR/MAPK signaling in LPS-induced RAW264.7 cells.
abstract: Soybeans, produced by Glycine max (L.) Merr., contain high levels of isoflavones, such as genistein and daidzein. However, soy leaves contain more diverse and abundant flavonol glycosides and coumestans, as compared to the soybean. This study investigated the anti-inflammatory effects of the major coumestans present in soy leaf (coumestrol, isotrifoliol, and phaseol) in lipopolysaccharide (LPS)-induced RAW264.7 cells. Coumestans significantly reduced LPS-induced nitric oxide (NO), prostaglandin E2 (PGE2), and reactive oxygen species (ROS) production; isotrifoliol had the most potent anti-inflammatory activity. Isotrifoliol reduced LPS-mediated induction of mRNA expression of inducible nitric-oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin (IL)-1β, IL-6, tumor necrosis factor alpha (TNFα), and chemokines, such as chemokine (C-C motif) ligand (CCL) 2, CCL3, and CCL4. Isotrifoliol prevented NF-κB p65 subunit activation by reducing the phosphorylation and degradation of the inhibitor of NF-κB. And isotrifoliol significantly suppressed phosphorylation of the extracellular signal-regulated protein kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK). Furthermore, isotrifoliol suppressed LPS-induced Toll-like Receptor (TLR) signaling pathway, including mRNA expression of TNF receptor associated factor 6, transforming growth factor beta-activated kinase 1 (TAK1), TAK1 binding protein 2 (TAB2), and TAB3. These results demonstrate that isotrifoliol exerts an anti-inflammatory effect by suppressing the expression of inflammatory mediators via inhibition of TLR/NF-κB and TLR/MAPK signaling in LPS-induced RAW264.7 macrophages. Therefore, isotrifoliol can be used as an anti-inflammatory agent, and coumestan-rich soy leaf extracts may provide a useful dietary supplement.
authors.affiliation: Industrial Bio-materials Research Center, KRIBB, Daejeon 34141, Republic of Korea; Department of Biomolecular Science, Korea University of Science and Technology, KRIBB, Daejeon 34141, Republic of Korea.
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.affiliation: Industrial Bio-materials Research Center, KRIBB, Daejeon 34141, Republic of Korea.
authors.forename: Jeong-Hyun
authors.initials: JH
authors.lastname: Yoon
authors.affiliation: Department of Biomolecular Science, Korea University of Science and Technology, KRIBB, Daejeon 34141, Republic of Korea.
authors.forename: Hyo-Jun
authors.initials: HJ
authors.lastname: Won
authors.affiliation: Industrial Bio-materials Research Center, KRIBB, Daejeon 34141, Republic of Korea; College of Pharmacy, Chungnam National University, Daejeon 34134, Republic of Korea.
authors.forename: Hyeon-Seon
authors.initials: HS
authors.lastname: Ji
authors.affiliation: Industrial Bio-materials Research Center, KRIBB, Daejeon 34141, Republic of Korea.
authors.forename: Heong Joo
authors.initials: HJ
authors.lastname: Yuk
authors.affiliation: Division of Applied Life Science, Gyeongsang National University, Jinju 52828, Republic of Korea.
authors.forename: Ki Hun
authors.initials: KH
authors.lastname: Park
authors.affiliation: Industrial Bio-materials Research Center, KRIBB, Daejeon 34141, Republic of Korea; Insect Biotech Co. Ltd., Daejeon 34054, Republic of Korea.
authors.forename: Ho-Yong
authors.initials: HY
authors.lastname: Park
authors.affiliation: Industrial Bio-materials Research Center, KRIBB, Daejeon 34141, Republic of Korea; Department of Biomolecular Science, Korea University of Science and Technology, KRIBB, Daejeon 34141, Republic of Korea. Electronic address: tsjeong@kribb.re.kr.
authors.forename: Tae-Sook
authors.initials: TS
authors.lastname: Jeong
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000302:isolation & purification / Q000494:pharmacology*; D016207:Cytokines / Q000378:metabolism; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology*; D007249:Inflammation / Q000188:drug therapy*; D018836:Inflammation Mediators / Q000378:metabolism; D008070:Lipopolysaccharides / Q000276:immunology; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D018515:Plant Leaves; D000067996:RAW 264.7 Cells; D015398:Signal Transduction / Q000187:drug effects*; D013025:Glycine max / Q000276:immunology; D051193:Toll-Like Receptors / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D000893:Anti-Inflammatory Agents; D016207:Cytokines; D005419:Flavonoids; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D016328:NF-kappa B; D051193:Toll-Like Receptors; C420347:isotrifoliol; D048051:p38 Mitogen-Activated Protein Kinases
keywords: Anti-inflammation; Coumestans; Isotrifoliol; MAPK; Macrophages; NF-κB