title: Anti-inflammatory effects of ethanol extracts of Chinese propolis and buds from poplar (Populus×canadensis).
abstract: BACKGROUND
  Propolis is used widely in a number of cultures as a folk medicine and is gaining wider recognition for its potential therapeutic use, due to its wide range of biological properties and pharmacological activities, especially its anti-inflammatory effects. Despite an increasing number of studies focused on the biological activities of propolis together with its botanical sources, studies on Chinese propolis are insufficient. This study was designed to investigate the anti-inflammatory properties of ethanol extracts from Chinese propolis (EECP) and poplar buds (EEPB) from Populus×canadensis Moench (Salicaceae family).
  
  
  METHODS
  Phytochemical analysis of EECP and EEPB was performed via total phenolic and flavonoid content measurements followed by high-performance liquid chromatography (HPLC) analysis. DPPH and ABTS free-radical scavenging methods were used to evaluate their anti-oxidant properties. The anti-inflammatory effects of EECP and EEPB were investigated in vitro by evaluating their modulating effects on the key inflammatory cytokines and mediators in LPS/IFN-γ co-stimulated RAW 264.7 cells and by measuring nuclear factor (NF)-κB activation in TNF-α or IL-1β stimulation HEK 293 cells using reporter gene assays. Their effects on acute inflammatory symptoms (LPS-induced endotoxemia and acute pulmonary damage) were also examined in mice.
  
  
  RESULTS
  EECP and EEPB exhibited strong free-radical scavenging activity and significant in vitro anti-inflammatory effects by modulating key inflammatory mediators of mRNA transcription, inhibiting the production of specific inflammatory cytokines, and blocking the activation of nuclear factor (NF)-κB. The administration of EECP and EEPB (25 and 100 mg/kg) provided significant protective effects by attenuating lung histopathological changes and suppressing the secretion of LPS-stimulated inflammatory cytokines, such as interleukin-6 (IL-6), IL-10, MCP-1, TNF-α and IL-12p70 production in endotoxemic mice.
  
  
  CONCLUSIONS
  The results presented here reveal the potent anti-inflammatory properties of Chinese propolis and poplar buds, and provide biological information for developing suitable substitute(s) for propolis in the prevention and treatment of inflammatory diseases.
authors.affiliation: College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.affiliation: College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Jianglin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Shun
authors.initials: S
authors.lastname: Ping
authors.affiliation: Laboratory Animal Research Center, Zhejiang Chinese Medical University, Hangzhou 310053, China.
authors.forename: Quanxin
authors.initials: Q
authors.lastname: Ma
authors.affiliation: Zhejiang Academy of Traditional Chinese Medicine, Hangzhou 310007, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Chen
authors.affiliation: School of Life Science, Liaocheng University, Liaocheng 252059, China.
authors.forename: Hongzhuan
authors.initials: H
authors.lastname: Xuan
authors.affiliation: College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; Husbandry and veterinary technical popularization center of Zhejiang Province, Hangzhou 310020, China.
authors.forename: Jinhu
authors.initials: J
authors.lastname: Shi
authors.affiliation: College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Cuiping
authors.initials: C
authors.lastname: Zhang
authors.affiliation: College of Animal Sciences, Zhejiang University, Hangzhou 310058, China. Electronic address: flhu@zju.edu.cn.
authors.forename: Fuliang
authors.initials: F
authors.lastname: Hu
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D002460:Cell Line; D002681:China; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D016207:Cytokines / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D019446:Endotoxemia / Q000188:drug therapy / Q000473:pathology; D000431:Ethanol / Q000737:chemistry; D016166:Free Radical Scavengers / Q000302:isolation & purification / Q000494:pharmacology; D057809:HEK293 Cells; D006801:Humans; D007249:Inflammation / Q000188:drug therapy / Q000473:pathology; D018836:Inflammation Mediators / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity; D008264:Macrophages / Q000187:drug effects; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010936:Plant Extracts / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D032107:Populus / Q000737:chemistry*; D011429:Propolis / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000893:Anti-Inflammatory Agents; D016207:Cytokines; D016166:Free Radical Scavengers; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D010936:Plant Extracts; D000431:Ethanol; D011429:Propolis
keywords: Anti-inflammatory; Anti-oxidant; Chinese propolis; NF-κB; Poplar buds