title: Antinociceptive and hypnotic properties of Celastrus orbiculatus.
abstract: BACKGROUND
  Celastrus orbiculatus, a woody vine of the Celastraceae family, has been widely used as a traditional medicine for the treatment of many diseases, including rheumatoid arthritis and odontalgia. In this study, we assessed the sedative and antinociceptive activities of the methanolic extract of Celastrus orbiculatus (MCO).
  
  
  METHODS
  The antinociceptive effect of MCO was evaluated using several experimental pain models, including thermal nociception methods, such as the tail immersion and the hotplate tests, as well as chemical nociception induced by intraperitoneal acetic acid and subplantar formalin administration in mice. To verify the possible connection of the opioid receptor to the antinociceptive activity of MCO, we performed a combination test with naloxone, a nonselective opioid receptor antagonist. The sedative effect of MCO was studied using the pentobarbital-induced sleeping model.
  
  
  RESULTS
  MCO demonstrated strong and dose-dependent antinociceptive activity compared to tramadol and indomethacin in various experimental pain models. The combination test using naloxone revealed that the antinociceptive activity of MCO is associated with activation of the opioid receptor. MCO also caused decreased sleep latency and increased sleeping time in the pentobarbital-induced sleeping model; however, MCO alone did not induce sleep.
  
  
  CONCLUSIONS
  In the present study, MCO showed potent antinociceptive and sedative activities. Based on these results, MCO may be considered a valuable anti-nociceptive and hypnotic agent for the treatment of various diseases.
authors.affiliation: College of Pharmacy, Woosuk University, Chonbuk 565-701, Republic of Korea.
authors.forename: Ho Joon
authors.initials: HJ
authors.lastname: Park
authors.forename: Dong Seok
authors.initials: DS
authors.lastname: Cha
authors.forename: Hoon
authors.initials: H
authors.lastname: Jeon
mesh_terms: D019342:Acetic Acid; D000818:Animals; D031247:Celastrus / Q000737:chemistry; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D005557:Formaldehyde; D006993:Hypnotics and Sedatives / Q000302:isolation & purification / Q000494:pharmacology*; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010146:Pain / Q000139:chemically induced / Q000503:physiopathology / Q000517:prevention & control*; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects*; D010634:Phenobarbital / Q000494:pharmacology; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal; D011930:Reaction Time / Q000187:drug effects; D012890:Sleep / Q000187:drug effects*; D013997:Time Factors; D014147:Tramadol / Q000494:pharmacology
chemical_list: D006993:Hypnotics and Sedatives; D009292:Narcotic Antagonists; D010936:Plant Extracts; D005557:Formaldehyde; D009270:Naloxone; D014147:Tramadol; D019342:Acetic Acid; D007213:Indomethacin; D010634:Phenobarbital