Evaluation of pharmacological mechanisms of antinociceptive effect of Teucrium polium on visceral pain in mice.

Summary Teucrium polium is used for treatment of visceral pain in Iranian folkloric medicine. In this study antinociceptive mechanisms of T. polium hydroethanolic extract were examined by acetic acid-induced writhing test as a model of visceral pain in male NMRI mice. To reveal the antinociceptive mechanisms of the extract, we examined the effects of opioidergic, serotonergic, adrenergic and histaminergic antagonists on extract-induced antinociception. The results of this study showed that pretreatment with naloxone, chlorpheniramine and cimetidine significantly attenuate the antinociceptive effect of the extract. However, cyproheptadine and phentolamine had no effect. Our results clearly show antinociceptive effects of T. polium may be mediated by opioidergic and histaminegic H1 and H2 receptors.