Evaluate the analgesic opiate receptors of hops (Humulus lupulus L.) extract in mice

The substances can produce analgesia by different receptors and the most important receptor is opiate receptor. Opiates agonists produced analgesia by binding specific G protein-coupled receptors located primarily in brain and spinal cord regions involved in the transmission and modulation of pain. Hops with its scientific name Humulus Lupulus have hormonic and analgesic properties which is produced by Lopolon in plant. In this study formalin test was used as a standard pain inducing test and the analgesic effect of naloxan (5mg/kg) as an inhibitor of opiate receptor were compared to 10mg/kg of hops extract. The results show that, hops extract has no analgesic property by pretreatment of naloxan and the pain response is not significant as compared to normal saline. The pretreatment of naloxan by applying hops extract pain response is significantly increased in inflammatory phase of formalin test. This may be due to the hops arising from opiate receptors.