白鲜皮主要药效成分白鲜碱、黄柏酮、梣酮的抗皮炎作用比较及机制研究

Comparison and mechanism study on the anti⁃dermatitis effects of the main pharmaco⁃dynamic components of cortex dictamni including obacunone,dictamnine,and fraxinellone

目的:比较中药白鲜皮的3种主要活性成分白鲜碱、黄柏酮、梣酮在特应性皮炎(atopic dermatitis,AD)治疗中的作用并探讨其机制。方法:利用2,4⁃二硝基氟苯(2,4⁃dinitrofluorobenzene,DNFB)构建小鼠皮炎模型,观察白鲜皮醇提物、白鲜碱、黄柏酮、梣酮、地塞米松对AD小鼠引起的慢性瘙痒的作用;采用皮损评分评估小鼠皮损严重程度。苏木精⁃伊红(hematoxy⁃lin⁃eosin,HE)和甲苯胺蓝染色评估小鼠表皮厚度和肥大细胞数目。酶联免疫吸附试验(enzyme⁃linked immunosorbent assay,ELISA)检测小鼠皮损组织中白介素(interleukin,IL)⁃4、IL⁃31、IL⁃10水平;Western blot检测Janus激酶(janus kinase,JAK)1、p⁃JAK1、信号转导和转录激活因子(signal transducer and activator of transcription,STAT)3、p⁃STAT3、STAT6、p⁃STAT6的蛋白水平。结果:AD小鼠引起的慢性瘙痒能明显被白鲜皮醇提物抑制。与模型组相比,白鲜皮的3种主要活性成分中:白鲜碱和梣酮能明显抑制AD小鼠引起的慢性瘙痒,改善皮损症状和炎症细胞浸润,下调IL⁃4、IL⁃31水平,上调IL⁃10水平,并抑制JAK1⁃STAT3/STAT6信号通路,但黄柏酮组与模型组比较差异无统计学意义。结论:白鲜碱和梣酮可能是白鲜皮发挥抗皮炎作用的主要活性成分。

Objective:To compare the effects of three main active components of cortex dictamni namely obacunone,dictamnine,and fraxinellone,in the treatment of atopic dermatitis(AD)and explore their mechanisms.Methods:The AD mouse model was established using 2,4⁃dinitrofluorobenzene(DNFB),and the effects of ethanol extract of cortex dictamni,obacunone,dictamnine,fraxinellone,and dexamethasone on chronic itch induced by AD in mice were observed.The severity degree of skin lesions in mice was evaluated using a skin lesion scoring system.Hematoxylin⁃eosin(HE)and toluidine blue staining were used to evaluate epidermal thickness and mast cell count in mice.Enzyme⁃linked immunosorbent assay(ELISA)was used to detect the levels of interleukin(IL)⁃4,IL⁃31,and IL⁃10 in mouse skin lesions.Western blot was used to detect the protein levels of Janus kinase(JAK1),phosphorylated JAK1(p⁃JAK1),signal transducer and activator of transcription(STAT)3,p⁃STAT3,STAT6 and p⁃STAT6.Results:Chronic itch induced by AD in mice was significantly inhibited by the ethanol extract of cortex dictamni.Compared with the model group,two of the three main active componentsof Cortex dictamni,namely dictamnine and fraxinellone,significantly inhibited the chronic itch induced by AD in mice,improved skin lesion symptoms and inflammatory cell infiltration,downregulated the levels of IL⁃4 and IL⁃31,upregulated the levels of IL⁃10,and inhibited the JAK1⁃STAT3/STAT6 signaling pathway.However,there was no significant difference between the obacunone group and the model group.Conclusion:Dictamnine and fraxinellone may be the main active components of cortex dictamnitoin exerting anti⁃dermatitis effect.