title: Anti-nociceptive activity of the crude extract of Myrianthus arboreus P. Beauv (Cecropiaceae) in mice.
abstract: BACKGROUND
  Myrianthus arboreus P. Beauv (Cecropiaceae) is a shrub or a tree plant widely distributed in Tropical Africa. In the South Eastern part of Nigeria, the leaves are used in traditional medicine as an analgesic for muscular pains, and also as an enema to relieve pain in the back and loins. Although no scientific study has been performed to validate its traditional use in pain management, this study therefore aims at investigating the anti-nociceptive activity of M. arboreus leaves extract in mice.
  
  
  METHODS
  Anti-nociceptive activity of M. arboreus was investigated using acetic acid induced writhing, formalin induced paw licks, hot plate, and tail flick tests. Acute toxicity was determined using a slightly modified Lorkes method.
  
  
  RESULTS
  The extract of M. arboreus produced a significant dose-dependent [F (4, 20)=13.48 p<0.001] inhibition of abdominal writhings induced by acetic acid. In the formalin paw licking test, it produced a significant dose-dependent inhibition of neurogenic and inflammatory pain [F (4, 17.5)=60.13 p<0.001]. It also produced a significant dose dependent [F (4, 20)=30.5 p<0.001; F (4, 20)=0.321 p<0.0001] prolongation of the latency and reaction time in the hot plate and tail immersion tests. Peak effect was observed at the highest dose (40 mg/kg). LD50 of the plant was found to be 894 mg/kg.
  
  
  CONCLUSIONS
  M. arboreus possesses potent antinociceptive activity mediated centrally and peripherally, an effect which may justify its traditional use in the management of pain.
authors.affiliation: Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Ibadan, Nigeria. Electronic address: lizzyolonode@gmail.com.
authors.forename: Elizabeth Toyin
authors.initials: ET
authors.lastname: Olonode
authors.affiliation: Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Ibadan, Nigeria.
authors.forename: Adegbuyi Oladele
authors.initials: AO
authors.lastname: Aderibigbe
authors.affiliation: Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Ibadan, Nigeria.
authors.forename: Adewale Ganiyu
authors.initials: AG
authors.lastname: Bakre
mesh_terms: D019342:Acetic Acid; D000700:Analgesics / Q000627:therapeutic use* / Q000633:toxicity; D000818:Animals; D045424:Complex Mixtures / Q000627:therapeutic use / Q000633:toxicity; D005557:Formaldehyde; D006358:Hot Temperature; D007928:Lethal Dose 50; D051379:Mice; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use* / Q000633:toxicity; D018515:Plant Leaves; D027003:Urticaceae
chemical_list: D000700:Analgesics; D045424:Complex Mixtures; D010936:Plant Extracts; D005557:Formaldehyde; D019342:Acetic Acid
keywords: Acetic acid (PubChem CID: 176); Acetylsalicylic acid (PubChem CID: 2244); Anti-nociception; Formalin (PubChem CID: 712); Morphine (PubChem CID: 5464110); Myrianthus arboreus; Naloxone (PubChem CID: 5464092); Tail immersion; Tail-flick; Writhing reactions