Analgesic and anti-inflammatory potential of aerial parts of the Daphne mucronata Royle extract in mice: Opioid-independent action

ObjectiveTo investigate the analgesic and anti-inflammatory property and possible involvement of opioid receptors of ethyl acetate extract from aerial parts of Daphne mucronata (D. mucronata) in mice by formalin test.MethodsSingle doses of 2.5, 5.0 and 10.0 mg/kg of body weight of ethyl acetate extract of D. mucronata were intraperitoneally administered to the mice 30 min before analgesic test. The anti-nociceptive effect of preparations was evaluated based on the formalin in mice.ResultsThe results indicated that the extract (2.5, 5.0 and 10.0 mg/kg) increased the pain threshold of mice and induced analgesia in both phases of formalin test. Like morphine sulfate (5.0 mg/kg, i.p.), the extract also showed more effective analgesic effect on the late phase of formalin test. Pre-treatment of animals with naloxone (5.0 mg/kg i.p.) did not inhibit the effects of the extract.ConclusionsOur findings suggest that D. mucronata contains potential analgesic and anti-inflammatory compounds which support its traditional use. Moreover, it seems that the analgesic and anti-inflammatory effects of the extract is mediated by non-opioid mechanisms. Further pharmacological studies are required to determine whether the analgesic mechanisms are actually responsible for such properties.