title: Complete Freund's adjuvant-induced acute inflammatory pain could be attenuated by triptolide via inhibiting spinal glia activation in rats.
abstract: BACKGROUND
  Inflammatory pain is one of the most common clinical symptoms, mechanical allodynia and thermal hypersensitivities are associated with proinflammatory cytokines, and proinflammatory cytokine antagonists could alleviate the hypersensitivity. Previous studies showed that a traditional Chinese medicine ingredient, triptolide could inhibit inflammatory cytokines; however, it was still unknown whether triptolide had beneficial effects on treating inflammatory pain.
  
  
  METHODS
  The effects of triptolide on Complete Freund's Adjuvant-induced acute inflammatory pain were investigated using behavioral tests. The activation of spinal glia was morphologically observed by immunofluorescent histochemistry. The levels of OX42, glia fibrillary acidic protein, and phosphorylated extracellular signal-regulated kinase in the spinal cord were detected by Western blot, and the messenger RNA levels of interleukin 1β, interleukin 6, and tumor necrosis factor alpha were detected by real-time polymerase chain reaction.
  
  
  RESULTS
  These results demonstrate that the triptolide effectively attenuates inflammatory pain induced by Complete Freund's Adjuvant, the underlying mechanism may regulate the phosphorylated extracellular signal-regulated kinase signaling pathway and inhibit the spinal glia activation, and then downregulate the proinflammatory cytokines; the triptolide may be clinically useful as a drug of anti-inflammatory pain.
  
  
  CONCLUSIONS
  In the present study, we first reported that repeated systemic administration of triptolide could safely prevent and reverse inflammatory pain. The triptolide may serve as a new potential compound for developing safe therapeutics for patients suffering inflammatory pain.
authors.affiliation: Department of Radiation Oncology, PLA 302 Hospital, Beijing, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Xu
authors.affiliation: Department of Clinical Laboratory, PLA 302 Hospital, Beijing, China.
authors.forename: Youhan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Medical Branch, PLA 302 Hospital, Beijing, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Osteology, PLA 304 Hospital, Beijing, China.
authors.forename: Yunqing
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Medical Branch, Air force General Hospital, Beijing, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Zhao
authors.affiliation: Department of Ophthalmology, Naval General Hospital, Beijing, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Oncology, Hainan branch of PLA General Hospital, Beijing, China. Electronic address: qianniansong1@163.com.
authors.forename: Niansong
authors.initials: N
authors.lastname: Qian
authors.affiliation: Department of Oncology, Hainan branch of PLA General Hospital, Beijing, China. Electronic address: zhh301@sina.com.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Radiation Oncology, PLA 302 Hospital, Beijing, China. Electronic address: 326308005@qq.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Li
mesh_terms: D059787:Acute Pain / Q000139:chemically induced / Q000188:drug therapy*; D000818:Animals; D016207:Cytokines / Q000378:metabolism; D004224:Diterpenes / Q000494:pharmacology / Q000627:therapeutic use*; D004353:Drug Evaluation, Preclinical; D004789:Enzyme Activation; D004852:Epoxy Compounds / Q000494:pharmacology / Q000627:therapeutic use; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005620:Freund's Adjuvant; D007166:Immunosuppressive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D007249:Inflammation / Q000188:drug therapy; D018836:Inflammation Mediators / Q000378:metabolism; D008297:Male; D009457:Neuroglia / Q000187:drug effects*; D010616:Phenanthrenes / Q000494:pharmacology / Q000627:therapeutic use*; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D016207:Cytokines; D004224:Diterpenes; D004852:Epoxy Compounds; D007166:Immunosuppressive Agents; D018836:Inflammation Mediators; D010616:Phenanthrenes; D010936:Plant Extracts; C001899:triptolide; D005620:Freund's Adjuvant; D048049:Extracellular Signal-Regulated MAP Kinases
keywords: Glia; Inflammatory pain; Triptolide; pERK