Study on the mechanism of Mianyu Tie in promoting the recovery of nerve function after acute facial nerve injury in Balb/c mice

Liu Xiaoqing; Zhao Ge; Liang Xiaoyan; Zheng Cuijuan; Zhang Rui

doi:10.3969/j.issn.1002-1949.2024.07.010

Abstract：Objective To investigate the effect and potential mechanism of Mianyu Tie in promoting the recovery of nerve function after acute facial nerve injury.Methods A total of 120 SPF male Balb/c mice were randomly divided into Sham group(n=40),Model group(n=40)and treatment group(M+MYT,n=40).The models of acute facial nerve injury were established by pressing the trunk of facial nerve.After the successful establishment of the model,the M+MYT group mice were treated with Mianyu Tie for 24 h,the Sham group and the Model group were not treated,and the facial nerve function of each group was scored every 24 h.On the 9th day after operation,the brainstem facial nucleus,facial nerve trunk and blood samples of eyeball vein were collected.Hematoxylin-eosin(HE)staining and transmission electron microscopy were used to observe the morphological changes in the facial nerve trunk and facial nucleus neuron.Immunofluorescence and Western blot were used to detect the expression of monocyte chemoattractant protein-1(MCP-1),tumour necrosis factor-α(TNF-α),inducible nitric oxide synthase(iNOS),endothelial nitric oxide synthase(eNOS),endothelin-1(ET-1)and vascular endothelial growth factor(VEGF)in mouse facial nucleus neuron,respectively.Enzyme-linked immunosorbent assay(ELISA)was used to detect the content of MCP-1,TNF-α,iNOS,eNOS,ET-1 and VEGF in serum.Nitrate reductase method was used to detect the concentration of nitric oxide(NO)in serum.Results On 9th day after operation,the facial nerve function score in the M+MYT group was lower than that in the Model group(P＜0.05).HE staining and transmission electron microscopy indicated that the injury to facial nucleus neurons and nerve fibers in the M+MYT group was significantly improved compared with the Model group.Immunofluorescence,Western blot and ELISA methods showed that the expression of MCP-1,TNF-α,iNOS,ET-1 and VEGF in the M+MYT group was significantly lower than that in the Model group(P＜0.05),eNOS expression was higher than that in the Model group(P＜0.05).Nitrate reductase method showed that the concentration of NO was the highest in the M+MYT group and the lowest in the Sham group(P＜0.01).Conclusions Mianyu Tie can reduce the expression of MCP-1,TNF-α,iNOS,ET-1 and VEGF and enhance the expression of NO and eNOS,effectively control inflammation,protect micro vascular endothelial function,reduce vascular permeability,and promote the recovery of nerve function after acute facial nerve injury.