RESUMO
Aim To investigate the periphery analge-sic effect of myricetin on a rat model of inflammatory pain and the mechanism. Methods Rat models of in-flammatory pain were induced by complete Freund ’ s adjuvant ( CFA) injection in left hindlimb plantar cen-ter. The thermal withdrawal latency ( TWL) was meas-ured before and after CFA or myricetin treatment. Elec-trophysiological method was used to identify the effect of myricetin on the action potential frequency and the voltage dependent potassium channel currents in small DRG neurons. Results Rats with CFA injected showed thermal hyperalgesia ( P <0. 05 ) and TWL in-creased significantly after myricetin intraperitoneally in-jected ( P <0. 05 ) . Current clamp recording showed the action potential frequency of small DRG neurons in rats was inhibited by myricetin ( P<0. 01 ) and voltage calmap recording showed the inhibitory effect of myr-icetin was enhanced by calcium depended potassium channel currents ( P<0. 05 ) . Conclusion Myricetin exerts periphery analgesic effect by enhancing calcium depended potassium channel currents and inhibiting excitability of small neurons of dorsal root ganglion.