title: Effects of an ethanol extract and the diterpene, xylopic acid, of Xylopia aethiopica fruits in murine models of musculoskeletal pain.
abstract: BACKGROUND
  Fruits of Xylopia aethiopica (Dunal) A. Rich. (Annonaceae) are used traditionally to manage arthritis, headache and other pain disorders.
  
  
  OBJECTIVE
  The analgesic properties of the X. aethiopica ethanol fruit extract (XAE) and xylopic acid (XA) were evaluated in musculoskeletal pain models.
  
  
  METHODS
  Acute muscle pain was induced in gastrocnemius muscle of Sprague-Dawley rats with 3% carrageenan (i.m.). Rats received XAE (30-300 mg/kg), XA (10-100 mg/kg) or morphine (1-10 mg/kg) after 12 h. Effects of XAE and XA on muscle pain were assessed by measuring post-treatment grip strength of the rats. Chronic muscle pain was similarly induced, but drug treatment was on the eighth day and effects of XAE and XA assessed with Randall-Selitto test for hyperlagesia. Acute-skeletal pain was induced in knee joints of rats with 3% carrageenan-kaolin mixture and effects determined 12-h later. Similar induction protocol was used for chronic knee pain with treatment and measurement as done for chronic muscle pain.
  
  
  RESULTS
  XAE and XA significantly and dose-dependently ameliorated both acute muscle (ED50mg/kg: XAE = 22.9; XA = 6.2) and skeletal hyperalgesia (XAE = 39.9; XA = 17.7) induced by 3% carrageenan. Similarly, chronic skeletal hyperalgesia was reduced by XAE and XA treatment similar to morphine (ED50: XAE = 13.0; XA = 4.6). This reduction was also seen in chronic muscle hyperalgesia (ED50: XAE = 79.1; XA = 42.7). XAE and XA significantly reduced the spread of hyperalgesia to contralateral limbs in both models of chronic hyperalgesia.
  
  
  CONCLUSIONS
  These findings establish analgesic properties of the ethanol fruit extract of X. aethiopica and xylopic acid in musculoskeletal pain.
authors.affiliation: a Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences , Kwame Nkrumah University of Science & Technology , Kumasi , Ghana.
authors.forename: Eric
authors.initials: E
authors.lastname: Woode
authors.affiliation: b Department of Biomedical and Forensic Sciences, School of Biological Science , University of Cape Coast , Cape Coast , Ghana.
authors.forename: Elvis Ofori
authors.initials: EO
authors.lastname: Ameyaw
authors.affiliation: a Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences , Kwame Nkrumah University of Science & Technology , Kumasi , Ghana.
authors.forename: Eric
authors.initials: E
authors.lastname: Boakye-Gyasi
authors.affiliation: a Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences , Kwame Nkrumah University of Science & Technology , Kumasi , Ghana.
authors.forename: Wonder Kofi Mensah
authors.initials: WK
authors.lastname: Abotsi
authors.affiliation: c Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences , Kwame Nkrumah University of Science & Technology , Kumasi , Ghana.
authors.forename: James
authors.initials: J
authors.lastname: Oppong Kyekyeku
authors.affiliation: c Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences , Kwame Nkrumah University of Science & Technology , Kumasi , Ghana.
authors.forename: Reimmel
authors.initials: R
authors.lastname: Adosraku
authors.affiliation: a Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences , Kwame Nkrumah University of Science & Technology , Kumasi , Ghana.
authors.forename: Robert Peter
authors.initials: RP
authors.lastname: Biney
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004224:Diterpenes / Q000302:isolation & purification / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000627:therapeutic use; D005260:Female; D005638:Fruit; D008297:Male; D059352:Musculoskeletal Pain / Q000188:drug therapy* / Q000378:metabolism; D010936:Plant Extracts / Q000302:isolation & purification / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016896:Treatment Outcome; D054336:Xylopia
chemical_list: D004224:Diterpenes; D010936:Plant Extracts; D000431:Ethanol
keywords: Acute pain; carrageenan; chronic pain; kaolin; morphine; myalgia