Study On The Antipruritic Mechanism Of Zanthoxylum Bungeanum And Zanthoxylum Schinifolium Volatile Oil On Chronic Eczema Based On H1R And PAR-2 Mediated GRPR Pathway

Objective: Observe the antipruritic effect of the volatile oil of Zanthoxylum bungeanum and Zanthoxylum schinifolium on chronic eczema model and the expression of histamine type 1receptor(H1R),protease-activated receptor 2(PAR-2),transient receptor potential vanilloid1(TRPV1),transient receptor potential Ankyrin 1(TRPA1),and gastrin-releasing peptide receptor(GRPR),and elucidate the antipruritic mechanism of Zanthoxylum bungeanum and Zanthoxylum bungeanum volatile oil in the treatment of chronic eczema.Methods: The model of chronic eczema was established by using 2,4-dinitrochlorobenzene(DNCB).The composition and content of volatile oil in Zanthoxylum schinifolium and Zanthoxylum bungeanum were determined by gas chromatography-mass spectrometry(GCMS);the antipruritic effect was evaluated by(EASI)score of eczema area and severity index and scratching times;the contents of histamine,gastrin-releasing peptide(GRP),interleukin-4(IL-4)and immunity globulin E(IgE)in serum of rats were determined by enzyme-linked immunosorbent assay(ELISA).The tissue morphology was observed by HE staining.The expressions of H1R,PAR-2,TRPV1,TRPA1,and GRPR were detected by immunohistochemistry,Western blot,and QRT-PCR.Results: There are differences in the content and composition of volatile oil between Zanthoxylum bungeanum and Zanthoxylum schinifolium.Compared with the model group,the difference of EASI score and scratching times in Zanthoxylum bungeanum group and Zanthoxylum schinifolium group were significantly increased,the concentrations of IL-4,IgE,GRP,and histamine were significantly decreased,the degree of inhibition on the pathological manifestations of chronic eczema was obvious,and the expression levels of H1R,PAR-2,TRPV1,and GRPR were significantly decreased.There was no significant difference in antipruritic effect between the two groups.The expression of TRPA1 is inconsistent at the protein and gene level,which needs to be further discussed.Conclusion: The volatile oil of Zanthoxylum bungeanum and Zanthoxylum schinifolium can reduce the expression of H1R,PAR-2,TRPV1,and GRPR.The mechanism may be through the intervention of H1R and PAR-2 mediated GRPR pathway to achieve the effect,both of which have the same antipruritic effect.