月季抗糠秕马拉色菌活性部位筛选及其抑制脂溢性皮炎的作用机制OA

Objective:To screen Chinese herbal medicines for optimal inhibitory activity against Malassezia furfur (M.furfur),and to identify the most potent anti-microbial fraction and investigate its mechanism of action. Methods:The Chinese herbal extract and its polar fractions exhibiting the strongest inhibitory effect against M. furfur were initially screened from twenty Chinese herbal medicines using the Oxford cup method and broth microdilution assay. A highly active subfraction was subsequently obtained through silica gel column chromatography. The effects of this active subfrac-tion on the growth and structural integrity of M. furfur cells were evaluated by turbidimetry,exogenous sorbitol hypertonic protection assay,extracellular alkaline phosphatase activity assay,propidium iodide fluorescence staining,and crystal violet staining. M. furfur-induced inflammatory models in HaCaT keratinocytes and SZ95 sebocytes were employed. The safety of the active subfraction was assessed by MTT assay for cell viability. Nitric oxide release was measured by the Griess test,and the levels of IL-6 and tumor necrosis factor (TNF)-α in cell supernatants were determined by enzyme-linked immunosorbent assay. Lipid synthesis in SZ95 cells was evaluated by Nile red staining. The chemical constituents of the highly active fraction obtained by silica gel column chromatography were analyzed and identified by ultra performance liquid chromatography-mass spectrometry (UPLC-MS). Potential anti-seborrheic dermatitis targets and pathways were predicted through constructing a protein-protein interaction network,Gene Ontology (GO) functional annotation,and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Results:Among the extracts of twenty Chinese herbal medicines,the extract of Rosa chinensis Jacq . demonstrated the most potent inhibitory activity against M. furfur. Its ethyl acetate fraction exhibited the most potent antimicrobial effect,from which subfraction Fr.2 was isolated as the most active component,with an inhibition zone diameter of (25.30±0.49) mm and a minimum inhibitory concentration of 1 mg/mL.Fr.2 effectively inhibited the growth of M. furfur and disrupted cellular structures,including the cell wall,cell membrane,and biofilm. Within a safe concentration range (25-100 µg/mL),Fr. 2 showed no cytotoxicity toward HaCaT and SZ95 cells and dose-dependently reduced the release of inflammatory factors in HaCaT cells and lipid synthesis in SZ95 cells.A total of 27 constituents were identified from Fr.2 by UPLC-MS,including organic acids,flavonoids,and alkaloids.The anti-seborrheic dermatitis effect of Fr.2 was associated with the regulation of core targets including TNF,chemokine C-X-C motif ligand 8,prostaglandin G/H synthase 2,signal transducer and activator of transcription 3,and epidermal growth factor receptor.GO analysis indicated that common targets of the drug and disease were primarily involved in neural signaling regulation and inflammatory modulation.KEGG pathway analysis further revealed that Fr.2 may exert its therapeutic effect on seborrheic dermatitis by modulating immune-inflammatory pathways,lipid metabolism and vascular function-related pathways,and neural signaling pathways.Conclusion:Rosa chinensis Jacq.exerts its antimicrobial effect against M.furfur by disrupting cell wall,cell membrane,and biofilm structures,and also demonstrates anti-seborrheic dermatitis activity,which may be attributed to the inhibition of inflammatory signaling pathways and the reduction of lipid synthesis.