高良姜素调节皮肤免疫稳态抗黑色素丢失的作用机制研究OA

Objective:To investigate the mechanism by which galangin,the primary active ingredient of traditional Chinese medicine(TCM)Alpiniae Officinarum Rhizoma,prevents skin depigmentation in mice.Methods:In vivo,imi-quimod(IMQ)was used to establish an adaptive immune model of mouse skin,and galangin cream was applied on the mice's back from day 2 of induction until day 7.Hematoxylin-eosin(HE)staining was used to detect pathological chan-ges in the skin tissue,while immunohistochemistry(IHC)and immunofluorescence(IF)were used to assess the expres-sion levels of F4/80,CD68,and CD8+T cells.Flow cytometry was employed to detect T cell subsets in the spleen and peripheral blood of mice.In vitro,lipopolysaccharide(LPS)was used to induce an inflammatory model of RAW264.7 cells.The culture supernatant of LPS-stimulated RAW264.7 cells treated with galangin was collected and co-cultured with B16F10 cells to measure B16F10 cell viability,melanin content,tyrosinase activity,and reactive oxygen species(ROS)levels,and the mRNA expression of inflammatory cytokines was determined by RT-qPCR.Results:Compared with those in the normal control group,mice in model control group exhibited a significantly increased number of erythe-ma,decreased percentage of melanin(P<0.05),and increased number of macrophages,CD68,and CD8+T cells(P<0.05),decreased CD45+T cells in the spleen,and increased CD45+T cells in peripheral blood.Meanwhile,the ratios of CD3+T/CD45+T cells and CD3+,CD8+T cells/CD4+T cells were downregulated(P<0.05).Compared with those in the model group,mice treated with galangin at a dose of 40 mg/kg showed a significantly decreased number of erythema,increased percentage of melanin(P<0.05),and decreased number of macrophages,CD68,and CD8+T cells in the skin(P<0.05),significantly increased proportion of CD45+T cells in the spleen,decreased CD45+T cells in peripheral blood,and reduced ratios of CD3+T/CD4+T cells and CD3+,CD8+T cells/CD45+T cells(P<0.05).At the cellular level,compared with those in the blank control group,the mRNA expression levels of inflammatory cytokines Il1β,iNos,and Il6 in LPS-stimulated RAW264.7 cells were significantly upregulated.Co-culture with B16F10 cells showed reduced B16F10 cell viability,melanin content,and tyrosinase activity.Compared with those in the model group,the mRNA ex-pression levels of inflammatory cytokines Il1β,iNos,and Il6 in 0.01 mmol/L galangin-treated RAW264.7 cells were downregulated.Increased cell viability,melanin content,and tyrosinase activity of melanocytes(P<0.05),and decreased ROS levels were also observed(P<0.05).Conclusion:Galangin may improve inflammation-mediated immune homeo-stasis by inhibiting the expression of inflammatory cytokines such as iNOS,thereby protecting melanocytes from T-cell-mediated damage,and ultimately preventing the loss of melanin.