Effect of Aqueous Extract of Trigonella foenum-graecum on Pain and Inflammation Induced by Formalin in Male Mice

Background: Studies have emphasized the effect of Trigonella foenum-graecum extract on the reduction of pain and inflammation. Objective: In this research we investigated the mechanisms of Trigonella foenum-graecum extract in reducing pain and inflammation induced by formalin. Methods: Male Albino mice (weight 20 - 25 g) were evaluated through the injection of 2 microliters of formalin to the plantar part of right foot. Following this, the rate of animal foot pain and inflammation were measured using Dubbison-Dennis and immersion in mercury. Trigonella foenum-graecum extract was injected 30 minutes before administration of formalin to the animals intraperitoneally. In addition, blood samples were taken from animals and corticosterone concentrations were measured. In an in vitro study the effect of extract on the activity of cyclooxygenase type 1 and 2 was assessed. Results: Our results showed that Trigonella foenum-graecum extract inhibits the first and second phase of pain induced by formalin, while inflammation is slightly reduced. Also the effect of Trigonella foenum-graecum extract is reversible with naloxone or memantine administration. Also Trigonella foenum-graecum extract could not increase plasma corticosterone level and was ineffective in activity of cyclooxygenase type 1 and 2 enzyme. Conclusion: Although Trigonella foenum-graecum extract can inhibit pain induced by formalin administration, but it seems that the reduction of pain is due to the possible interaction of components of Trigonella foenum-graecum extract with opioid and/or glutamate systems which occurs in the body and the mechanisms of inflammation reduction are not activated by the extract.