The role of opioids, serotonergic and cholinergic pain receptors to induce analgesic effect of Trachyspermum ammi essence using formalin test in mice

Objective: In previous studies it has been demonstrated that different substances, can inhibit pain occurred through opioids, serotonergic, and cholinergic pain receptors these receptors can be inhibited while in presence of naloxone, ondansetron and atropine. Therefore the aim of this study was to determine the effect of Trachyspermum ammi essence on modulation of pain score by the use of formalin test in mice. Methods: In this experimental study, 20 male mice (20-25) were included. They were randomly divided into test and control groups. The test groups were intraperitoneal injected specific amount of inhibitors such as naloxone, ondansetron and atropine. After 10 min these specimens were injected Trachyspermum ammi essence and were observed for 60 min.to score pain effect caused by formalin injection. Results: Our result indicated that mean score of the pain during the observation for 60 min (every 5 minutes) of formalin test in groups that received ondansetron, naloxone and TAE it is significantly decrease the pain score whiles group of atropine which induced before TAE significantly (P 0.05) increased the pain score. Conclusion: In conclusion, this research demonstrated the possible role of cholinergic signaling in antinociceptive effect. Thus more studies are required to prove the further effects of this essence on different signaling systems.