摘要
Objective To analyze and explore the analgesic effect of Angelica dahurica in neuropathic pain and its regulatory effect on the Mas-related G-protein coupled receptor member D(MrgprD)-transient receptor potential ankyrin 1(TRPA1)signaling pathway,using a mouse model of sciatic nerve chronic constriction injury(CCI).Methods A CCI mouse model was prepared by sterile surgical ligation and wrapping of the sciatic nerve in 30 mice.Pain-related behavioral changes induced by mechanical stimulation were detected by the VonFrey method,and the thermal hyperalgesic effects of Angelica dahurica were evaluated by thermal radiation experiments.The effects of Angelica dahurica on the protein expression levels MrgprD and TRPA1,the number of dorsal root ganglion(DRG)positive neurons,and mRNA levels of MrgprD and TRPA1 in mice were detected by Western Blot,immunofluorescence,and reverse transcription-polymerase chain reaction,respectively.Differences in fluorescence signal intensity in HEK293 cells after single transfection and co-transfection with MrgprD and TRPA1 plasmids,respectively,were analyzed by calcium imaging experiments.Results A total of 25 CCI mouse models were successfully prepared,with a modeling rate of 83.33％(25/30).The mechanical threshold and foot retraction latency were significantly higher in CCI mice treated with Angelica dahurica compared with the control group(P＜0.05).Expression levels of MrgprD and TRPA1 proteins were significantly lower in CCI mice treated with Angelica dahurica than in the control group(P＜0.05).The number of MrgprD-and TRPA1-positive neurons in the DRG was significantly lower group(P＜0.05)and the mRNA levels of MrgprD and TRPA1 were also significantly lower in CCI mice treated with Angelica dahurica than in the control group(P＜0.05).The fluorescence intensity was significantly higher in HEK293 cells co-transfected with MrgprD and TRPA1 plasmids than in single-transfected and blank control cells(P＜0.05).Conclusions This study demonstrated that the MrgprD-TRPA1 pathway is an important target for neuropathic pain,and indicated that Angelica dahurica can inhibit neuropathic pain by regulating this signal transduction pathway.These result provide a foundation for further research on the development of new clinical analgesic drugs and analgesic mechanisms.