title: Eckols reduce dental pulp inflammation through the ERK1/2 pathway independent of COX-2 inhibition.
abstract: OBJECTIVE
  The aim of this study was to elucidate the role of 6-6 bieckol (EB1) and pholorofucofuroeckol-A (EB5) from brown seaweed marine algae (Eisenia bicyclis) on lipopolysaccharide (LPS)-induced inflammation in human dental pulp cells (HDPCs).
  
  
  METHODS
  The cytotoxicity of EB1 and EB5 was examined by MTT assay on LPS-induced human dental pulp cells. Their role on expression of inflammatory, odontogenic, and osteogenic molecules was determined by Western blot analysis. The dentin mineralization was checked by alkaline phosphatase activity.
  
  
  RESULTS
  The five compounds from E. bicyclis have different structure with non-cytotoxic in HDPCs. EB1 and EB5 showed anti-inflammatory properties and inhibited phosphorylated-extracellular signal-regulated kinase (p-ERK1/2) and phosphorylated-c-jun N-terminal kinases (p-JNK) without any cytotoxicity. In particular, EB1 inhibited cyclooxygenase-2 (COX-2) and p-ERK1/2 signaling, and EB5 inhibited only p-ERK1/2 signaling but not COX-2. Both compounds inhibited nuclear factor kappa-B (NF-κB) translocation. Furthermore, EB1 and EB5 increased dentinogenic and osteogenic molecules, and dentin mineralized via alkaline phosphatase activity (ALP) in LPS-induced HDPCs.
  
  
  CONCLUSIONS
  This study elucidates that EB1 and EB5 have different types of anti-inflammatory property and help in dentin formation. Therefore, these compounds derived from marine algae of E. bicyclis may be used as selective therapeutic strategies for pulpitis and oral diseases.
authors.affiliation: Department of Oral Biochemistry, Institute of Oral Bioscience, BK21 program, School of Dentistry, Chonbuk National University, Jeonju, Korea.
authors.forename: U
authors.initials: U
authors.lastname: Paudel
authors.forename: Y H
authors.initials: YH
authors.lastname: Lee
authors.forename: T H
authors.initials: TH
authors.lastname: Kwon
authors.forename: N H
authors.initials: NH
authors.lastname: Park
authors.forename: B S
authors.initials: BS
authors.lastname: Yun
authors.forename: P H
authors.initials: PH
authors.lastname: Hwang
authors.forename: H K
authors.initials: HK
authors.lastname: Yi
mesh_terms: D002478:Cells, Cultured; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D003782:Dental Pulp / Q000201:enzymology / Q000473:pathology*; D006801:Humans; D007249:Inflammation / Q000201:enzymology / Q000473:pathology*; D020935:MAP Kinase Signaling System; D012624:Seaweed
chemical_list: D052246:Cyclooxygenase 2 Inhibitors
keywords: 6-6 bieckol; COX-2; ERK1/2; Eisenia bicyclis; human dental pulp cells; pholorofucofuroeckol-A