Oleanolic Acid, a pentacyclic triterpene attenuates the mustard oil-induced colonic nociception in mice.

Abstract

Many natural terpenoid compounds from plants exhibit antinociceptive property but very few studies have addressed their efficacy in visceral models of nociception. The present study evaluated the antinociceptive potential of oleanolic acid, a pentacyclic triterpene in the mouse model of colonic nociception induced by mustard oil. We further examined the possible participation of opioid, alpha2-adrenergic, and transient receptor potential vanilloid 1 (TRPV1)-receptors in its mechanism. Mice were pretreated orally with oleanolic acid (3, 10, 30 mg/kg) or vehicle, and the pain-related behavioral responses to intracolonic injection of mustard oil was analysed. Oleanolic acid significantly suppressed the mustard oil-induced nociceptive behaviors at test doses of 10 and 30 mg/kg, in a dose-related manner. The antinociceptive effect of oleanolic acid (30 mg/kg) was significantly blocked by pretreatment with the opioid antagonist, naloxone (2 mg/kg, i.p.), while the alpha2-adrenoceptor antagonist, yohimbine (2 mg/kg, s.c.), had no effect. Pretreatment with ruthenium red (3 mg/kg, s.c.), a non-competitive TRPV1 antagonist alone caused significant inhibition of mustard oil-induced nociception but its co-administration with oleanolic acid produced neither antagonism nor potentiation of oleanolic acid antinociception. In the open-field test that detects sedative or motor abnormality, mice received 30 mg/kg oleanolic acid did not show any per se influence, but significantly inhibited the mustard oil-induced decrease in ambulation frequency. These data demonstrate the visceral antinociceptive potential of oleanolic acid that involves an opioid mechanism and possibly a modulatory influence on vanilloid-receptors, which needs further study.

• Authors: Juliana Lemos Maia, Roberto César Pereira Lima-Júnior, Juceni Pereira David, Jorge Mauricio David, Flávia Almeida Santos, Vietla Satyanarayana Rao
• Journal: Biological & pharmaceutical bulletin (Biol Pharm Bull) Vol. 29 Issue 1 Pg. 82-5 (Jan 2006) ISSN: 0918-6158 [Print] Japan
• PMID: 16394515 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Adrenergic alpha-2 Receptor Antagonists
• Adrenergic alpha-Antagonists
• Plant Oils
• TRPV Cation Channels
• TRPV1 protein, mouse
• Ruthenium Red
• Yohimbine
• Oleanolic Acid
• mustard oil

Topics

• Adrenergic alpha-2 Receptor Antagonists
• Adrenergic alpha-Antagonists (pharmacology)
• Animals
• Behavior, Animal (drug effects)
• Colonic Diseases (chemically induced, prevention & control)
• Dose-Response Relationship, Drug
• Male
• Mice
• Motor Activity (drug effects)
• Mustard Plant (chemistry, toxicity)
• Oleanolic Acid (pharmacology)
• Pain (chemically induced, prevention & control)
• Plant Oils (toxicity)
• Ruthenium Red (pharmacology)
• TRPV Cation Channels (metabolism)
• Yohimbine (pharmacology)