Antinociceptive mechanisms of Rosmarinus officinalis extract in mice using writhing test

Rosemary (Rosmarinus officinalis) is a common household plant grows in many parts of the world, including Iran. Rosemary leaves are used in folk medicine as an antispasmodic, analgesic, diuretic and ntiepileptic agent. The objective of this study was to investigate the antinociceptive mechanisms of rosemary extract using a writhing test as a model of visceral pain. Possible antinociceptive mechanisms were explored by testing the effects of naloxone (nonselective opioid antagonist), cyproheptadine (nonselective serotonin antagonist), Chicago sky blue 6B (inhibitor of glutamate uptake) and bicuculline (GABAA antagonist) on rosemary extract-induced antinociception. Results showed that rosemary extract (50, 100 and 200 mg/kg, i.p.) induces antinociceptive effects in a dose-dependent manner (p< .001). Pre-treatment with naloxone and bicuculline significantly reduced this effect (from 61.04% to 27.56%, and from 60.31% to 42.09%, respectively; p