title: The influences of temperature and naloxone on the antinociceptive activity of Corchorus olitorius L. in mice.
abstract: A series of preliminary studies was carried out to evaluate the antinociceptive (pain relief) activity of the aqueous extract of Corchorus olitorius L. leaves (COAE) and to determine the influence of temperature and opioid receptors on COAE activity using the abdominal constriction and hot plate tests in mice. COAE, at concentrations of 10, 25, 50, 75, and 100%, showed both peripheral and central antinociception that are non-concentration- and concentration-dependent respectively. The peripheral activity was clearly observed at a concentration of 25% and diminished at a concentration of 100%, while the central activity was observed at all the concentrations of COAE used. Furthermore, the insignificant results obtained indicated that this peripheral activity (at concentrations of 25 and 50%) was comparable to that of morphine (0.8 mg/kg). Pre-heating COAE at a temperature of 80 degrees C and 100 degrees C, or 60 degrees C and 80 degrees C was found to enhance its peripheral and central antinociception respectively. Pre-treatment with naloxone (10 mg/kg), a general opioid receptor antagonist, for 5 min, followed by COAE, was found to completely block its peripheral, but not central, antinociceptive activity. Based on this observation, we conclude that the antinociceptive activity exhibited by C. olitorius is enhanced by the increase in temperature and may be mediated peripherally, but not centrally, at least in part, via an opioid receptor.
authors.affiliation: School of Biotechnology and Life Sciences, Universiti Industri Selangor, Jalan Zirkon A7/A, Seksyen 7, 40000, Shah Alam, Selangor, Malaysia. shaza8174@hotmail.com
authors.forename: Z A
authors.initials: ZA
authors.lastname: Zakaria
authors.forename: M
authors.initials: M
authors.lastname: Safarul
authors.forename: R
authors.initials: R
authors.lastname: Valsala
authors.forename: M R
authors.initials: MR
authors.lastname: Sulaiman
authors.forename: C A
authors.initials: CA
authors.lastname: Fatimah
authors.forename: M N
authors.initials: MN
authors.lastname: Somchit
authors.forename: A M
authors.initials: AM
authors.lastname: Mat Jais
mesh_terms: D019342:Acetic Acid; D000700:Analgesics / Q000494:pharmacology*; D000701:Analgesics, Opioid / Q000008:administration & dosage; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin / Q000008:administration & dosage; D003085:Colic / Q000139:chemically induced / Q000517:prevention & control*; D032381:Corchorus / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009020:Morphine / Q000008:administration & dosage; D009270:Naloxone / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D010146:Pain / Q000517:prevention & control*; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D013696:Temperature
chemical_list: D000700:Analgesics; D000701:Analgesics, Opioid; D000894:Anti-Inflammatory Agents, Non-Steroidal; D009292:Narcotic Antagonists; D010936:Plant Extracts; D009270:Naloxone; D009020:Morphine; D019342:Acetic Acid; D001241:Aspirin