The Effect of Clove Essence on Tonic Pain In Mice

Objectives: Opioids are the most effective analgesics but they induce serious side effects such as dependence. So approaching to alternative antinociceptive agents has been the aim of many investigations. Previous studies have reported the effect of clove (Syzygium aromaticum) extract as a local sedative in toothache, and as an anesthetic drug in aquatics such as trout. In the present study we conducted to evaluate the effect of clove essence on tonic pain in mice.

Methods: In this study the Formalin test was used for assessing animal's pain sensation. 28 male Syrian mice were randomly divided into 4 groups. Animals received normal saline (control group) and 3 different doses of clove essence 0.1, 0.2 and 0.4mg/kg respectively (test groups) intraperitoneally 15min before Formalin test. Pain scores were assessed during 1 hour post Formalin injection and the pain rates were statistically analyzed for each 5min intervals.

Results: Our findings showed that clove essence attenuates pain responses in a dose dependent manner. This analgesic effect in comparison with normal saline was significant for all administered doses (P<0.05). The antinociception was more prominent in the inflammatory phase than the acute phase of Formalin test (P<0.05). Conclusion: According to our findings clove essence could attenuate the chronic pain induced by formalin injection in a dose dependant way.