Antinociceptive activity of flower buds extract of Sophora japonica and its main active ingredient quercetin in bee venom-induced rat model

Aim: Sophora japonica L. is one of the traditional medicines in the world for a long time. The major ingredients flavonoids are shown to various pharmacological and nutritional values. The study was performed to investigate the antinociceptive activity of methanolic extract (ME) and its main flavonoid quercetin from flower buds of S. japonica in the bee venom-induced rat model. Methods: The antinociceptive activity of the ME of flower buds from S. japonica (50-500 mg/kg) and the isolated compound quercetin (5-50 mg/kg) were evaluated by using bee venom-induced rat model after administrating respectively.Results: The administration of ME from S. japonica and quercetin significantly increased the tolerance to pain in SD rats in comparison to control. The ME of S. japonica and quercetin produced significant inhibition of both the early (neurogenic pain or acute pain, 0-10 min) and the late (inflammatory pain or tonic pain, 11-40 min) phases of bee venom-induced pain. Furthermore, the ME (100-500 mg/kg, i.p.) caused a significant increase in the latency to response in the hot-plate test. However, the quercetin (5-50 mg/kg, i.p.) had no significant effect in the hot-plate test. Conclusion: These results suggest that the ME of S. japonica and its main active ingredient quercetin appear to contribute for the antinociceptive property in the bee venom-induced rats. The investigation gives an evidence of potential uses of the flower buds extract of S. japonica and quercetin as medicines of adjunctive therapy pain. [J Intercult Ethnopharmacol 2014; 3(1.000): 9-14