摘要
Objective:To explore whether the ethanol extract of Herpetospermum caudigerum Wall(EHC),a Xizang medicinal plant traditionally used for treating liver diseases,can improve imiquimod-induced psoriasis-like skin inflammation.Methods:Immunohistochemistry and immunofluorescence staining were used to determine the effects of topical EHC use in vivo on the skin pathology of imiquimod-induced psoriasis in mice.The protein levels of interferon-γ(IFN-γ),tumor necrosis factor-a(TNF-a),and interleukin-17A(IL-17A)in mouse skin samples were examined using immunohistochemical staining.In vitro,IFN-γ-induced HaCaT cells with or without EHC treatment were used to evaluate the expression of keratinocyte-derived intercellular cell adhesion molecule-1(ICAM-1)and chemokine CXC ligand 9(CXCL9)using Western blotting and reverse transcription-quantitative polymerase chain reaction.The protein synthesis inhibitor cycloheximide and proteasome inhibitor MG132 were utilized to validate the EHC-mediated mechanism underlying degradation of ICAM-1 and CXCL9.Results:EHC improved inflammation in the imiquimod-induced psoriasis mouse model and reduced the levels of IFN-γ,TNF-a,and IL-17A in psoriatic lesions.Treatment with EHC also suppressed ICAM-1 and CXCL9 in epidermal keratinocytes.Further mechanistic studies revealed that EHC suppressed keratinocyte-derived ICAM-1 and CXCL9 by promoting ubiquitin–proteasome-mediated protein degradation rather than transcriptional repression.Seven primary compounds including ehletianol C,dehydrodiconiferyl alcohol,herpetrione,herpetin,herpetotriol,herpetetrone and herpetetrol were identified from the EHC using ultra-performance liquid chromatography-quadrupole-time of flight-mass spectrometry.Conclusion:Topical application of EHC ameliorates psoriasis-like skin symptoms and improves the inflammation at the lesion sites.
基金
supported by grants from the National Natural Science Foundation of China(Grant No.82174202,No.32270407 and No.82074428)
Natural Science Foundation of Sichuan Province(Grant No.2022NSFSC0726)
Innovative Team Projects of Shanghai Municipal Commission of Health(Grant No.2022CX001)
Innovation Foundation of the Affiliated Hospital of Chengdu University(Grant No.CDFYCX202209)
Major Research and Development Plan of Xizang Autonomous Region(Grant No.XZ202201ZY0031G).