title: Evaluation of antinociceptive effects of Crassocephalum bauchiense Hutch (Asteraceae) leaf extract in rodents.
abstract: BACKGROUND
  The leaves of Crassocephalum bauchiense have long been used in traditional Cameroonian medicine for the treatment of epilepsy, pain, inflammatory disorders, arthritis and intestinal pain.
  
  
  OBJECTIVE
  In this study, we attempted to identify the possible antinociceptive action of the aqueous extract and the alkaloid fraction prepared from the leaves of Crassocephalum baucheiense.
  
  
  METHODS
  Using acetic acid induced abdominal constrictions, formalin-, capsaisin- and glutamate-induced nociception, and hot plate assay procedures, the antinociceptive effects of the aqueous extract and the alkaloid fraction was assessed after oral administration in mice. Morphine sulfate was used as reference analgesic agent. Mice were submitted to the rota-rod task and open-field test in order to assess any non-specific muscle-relaxant or sedative effects of the extracts of Crassocephalum bauchiense. Male and female Swiss mice were used to assess acute toxicity of these extracts.
  
  
  RESULTS
  The aqueous extract and the alkaloid fraction of Crassocephalum bauchiense produced a significant antinociceptive effects in the acetic acid, formalin, glutamate, capsaicin and hot plate tests. These antinociceptive effects of Crassocephalum bauchiense were significantly attenuated by pretreatment with naloxone. The extracts of Crassocephalum bauchiense did not alter the locomotion of animals in the open-field or rotarod tests, which suggest a lack of a central depressant effect. The animals did not exhibit any acute toxicity to the aqueous extract and the alkaloid fraction, so it was not possible to calculate the LD(50).
  
  
  CONCLUSIONS
  The results confirm the popular use of Crassocephalum bauchiense as an antinociceptive, and contribute to the pharmacological knowledge of this species because it was shown that the aqueous extract and the alkaloid fraction of Crassocephalum bauchiense produced dose related antinociception in models of chemical and thermal nociception through mechanisms that involve an interaction with opioidergic pathway.
authors.affiliation: Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, P.O. Box 63 Buea, Cameroon. taiwe sotoing@yahoo.fr
authors.forename: Germain Sotoing
authors.initials: GS
authors.lastname: Taïwe
authors.forename: Elisabeth Ngo
authors.initials: EN
authors.lastname: Bum
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Talla
authors.forename: Théophile
authors.initials: T
authors.lastname: Dimo
authors.forename: Neteydji
authors.initials: N
authors.lastname: Sidiki
authors.forename: Amadou
authors.initials: A
authors.lastname: Dawe
authors.forename: Richard Marcel
authors.initials: RM
authors.lastname: Nguimbou
authors.forename: Paul Désiré Djomeni
authors.initials: PD
authors.lastname: Dzeufiet
authors.forename: Michel
authors.initials: M
authors.lastname: De Waard
mesh_terms: D019342:Acetic Acid; D000284:Administration, Oral; D000470:Alkaloids / Q000494:pharmacology; D000700:Analgesics / Q000008:administration & dosage / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D019659:Asteraceae / Q000737:chemistry; D001522:Behavior, Animal / Q000187:drug effects; D002211:Capsaicin; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D005557:Formaldehyde; D018698:Glutamic Acid; D006358:Hot Temperature; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010146:Pain / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control* / Q000523:psychology; D017288:Pain Threshold / Q000187:drug effects; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D018515:Plant Leaves; D010946:Plants, Medicinal; D012997:Solvents / Q000737:chemistry; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000470:Alkaloids; D000700:Analgesics; D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D010936:Plant Extracts; D012997:Solvents; D014867:Water; D005557:Formaldehyde; D009270:Naloxone; D018698:Glutamic Acid; D009020:Morphine; D019342:Acetic Acid; D002211:Capsaicin