title: Polygonum viviparum L. inhibits the lipopolysaccharide-induced inflammatory response in RAW264.7 macrophages through haem oxygenase-1 induction and activation of the Nrf2 pathway.
abstract: BACKGROUND
  Polygonum viviparum L. (PV) is a member of the family Polygonaceae and is widely distributed in high-elevation areas. It is used as a folk remedy to treat inflammation-related diseases. This study was focused on the anti-inflammatory response of PV against lipopolysaccharide (LPS)-induced inflammation in RAW264.7 macrophages.
  
  
  RESULTS
  Treatment with PV did not cause cytotoxicity at 0-50 µg mL(-1) in RAW264.7 macrophages, and the IC(50) value was 270 µg mL(-1). PV inhibited LPS-stimulated nitric oxide (NO), prostaglandin (PG)E(2) , interleukin (IL)-1β and tumour necrosis factor (TNF)-α release and inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 protein expression. In addition, PV suppressed the LPS-induced p65 expression of nuclear factor (NF)-κB, which is associated with the inhibition of IκB-α degradation. These results suggest that, among mechanisms of the anti-inflammatory response, PV inhibits the production of NO and these cytokines by down-regulating iNOS and COX-2 gene expression. Furthermore, PV can induce haem oxygenase (HO)-1 protein expression through nuclear factor E2-related factor 2 (Nrf2) activation. A specific inhibitor of HO-1, zinc(II) protoporphyrin IX, inhibited the suppression of iNOS and COX-2 expression by PV.
  
  
  CONCLUSIONS
  These results suggest that PV possesses anti-inflammatory actions in macrophages and works through a novel mechanism involving Nrf2 actions and HO-1. Thus PV could be considered for application as a potential therapeutic approach for inflammation-associated disorders.
authors.affiliation: School of Pharmacy, College of Pharmacy, Taipei Medical University, Taiwan.
authors.forename: Hui-Wen
authors.initials: HW
authors.lastname: Cheng
authors.forename: Kock-Chee
authors.initials: KC
authors.lastname: Lee
authors.forename: Khoot-Peng
authors.initials: KP
authors.lastname: Cheah
authors.forename: Ming-Long
authors.initials: ML
authors.lastname: Chang
authors.forename: Che-Wei
authors.initials: CW
authors.lastname: Lin
authors.forename: Joe-Sharg
authors.initials: JS
authors.lastname: Li
authors.forename: Wen-Yu
authors.initials: WY
authors.lastname: Yu
authors.forename: E-Tung
authors.initials: ET
authors.lastname: Liu
authors.forename: Chien-Ming
authors.initials: CM
authors.lastname: Hu
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000235:genetics; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects; D051547:Heme Oxygenase-1 / Q000096:biosynthesis*; D007249:Inflammation / Q000139:chemically induced / Q000517:prevention & control*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects* / Q000201:enzymology; D051379:Mice; D051267:NF-E2-Related Factor 2 / Q000187:drug effects* / Q000502:physiology; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000235:genetics; D010936:Plant Extracts / Q000494:pharmacology; D028502:Polygonum / Q000737:chemistry*
chemical_list: D000893:Anti-Inflammatory Agents; D016861:Cyclooxygenase Inhibitors; D008070:Lipopolysaccharides; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D010936:Plant Extracts; D052247:Nitric Oxide Synthase Type II; D051547:Heme Oxygenase-1; D051546:Cyclooxygenase 2