目的：本研究通过马齿苋挥发油干预辣椒素诱导角质层细胞内瘙痒模型，探究马齿苋对抗湿疹瘙痒的作用机制。方法：采用辣椒素诱导的SD大鼠角质层细胞作为胞内瘙痒模型，模型细胞分为模型组、马齿苋挥发油高、低剂量组，另设正常角质层细胞作为空白对照。实验结束后采用免疫荧光技术检测角质层细胞形态，采用流式细胞技术测定细胞内Ca²⁺浓度，采用酶联免疫法法测定白三烯、白细胞介素-31和H1羟色胺含量，RT-PCR测定角质层细胞中辣椒素受体蛋白基因表达，western blot测定辣椒素受体蛋白表达。结果：与模型组相比，马齿苋挥发油干预组的阳性角质层细胞数量明显减小（P<0.05），胞内Ca²⁺浓度明显降低（P<0.05），白三烯、白细胞介素-31和H1羟色胺含量均有明显减少（P<0.05），角质层细胞中辣椒素受体蛋白的基因和蛋白表达均明显减少（P<0.05）。结论：马齿苋挥发油可能通过下调辣椒素受体蛋白表达，减少炎症继发反应而产生止痒效应。

This study aimed to explore the mechanism of volatile oil from purslane in treating itch induced by eczema through establishing the itch model,stimulating the keratinocyte with capsaicine(CAP).SD rats were divided into the control group,the model group,the high dose group of volatile oil from purslane,and low dose group of volatile oil from purslane.After finishing the experiment,the morphology of keratinocytes was observed by immunofluorescence technique,while Ca²⁺ concentration was detected by flow cytometry,and the contents of leukotriene A4 methyl ester(LTA4),interleukin-31(IL-31)and hydroxy trptamine H1(HTH1)were quantified by ELISA assay.The expression of TRPV1 mRNA in keratinocytes was tested by RT-PCR,while the protein level of TRPV1 was quantified by western blot.Compared with the model group,it was found that the cell count of positive keratinocytes,the ^Ca2+ concentration,the levels of LTA4,IL-31 and HTH1,and the mRNA and protein expressions of TRPV1 in the high dose and low dose groups were significantly decreased(P<0.05).In conclusion,it was demonstrated that the volatile oil from purslane may relieve itch through inhibiting the activation of TRPV1 and reducing secondary inflammatory reaction.

国家自然科学基金委青年科学基金项目（81403405）：马齿苋提取物激活TRPV1调控痒信号通路治疗急性湿疹的分子机制研究，负责人：胡一梅。