Antinociceptive effect of stigmasterol on formalin-induced rat

Pain has been defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage. Nowadays we use analgesic or NSAIDs to alleviate pain but the usage of NSAIDs is associated with a lot of side effects. Therefore, it is believed to have less side effects by using natural sources as medicine to treat pain. This study was conducted to determine the antinociceptive effect of stigmasterol on formalin-induced inflammation in rats. Formalin induce pain in two distinct phases; phase 1 and phase 2. Phase 1 is an acute pain or neurogenic pain that will start from O to 5 minutes. Phase 2 is an inflammation pain observed from 5 to 60 minutes. Stigmasterol (10, 20 and 40 mg/kg) was given intraperitoneally 30 minutes prior to formalin injection intradermally on the plantar surface of the hind paw of each rat. Indomethacin is used as a reference drug in this study. The frequency of licking and biting were recorded up to 60 minutes. From our results, stigmasterol ( 40 mg/kg) and indomethacin (10 mg/kg) exhibit significant reduction of pain in phase 2. However, there was no significant difference in phase I between I Omg, 20mg and 40mg of stigmasterol in percentage of inhibition. In conclusion, stigmasterol (40 mg/kg, i.p.) reveals antinociceptive effect by inhibiting inflammatory mediators at the late phase and further studies need to be conducted to determine the exact mechanism of action.