摘要
目的:体外研究黄芩苷经由TLR4信号转导途径抗ESBLs大肠埃希菌感染的作用及其机制。方法:用临床分离ESBLs大肠埃希菌接种于单层生长的RAW264.7细胞培养板中以及用黄芩苷(25,50 mg.L-1)预处理的单层生长的RAW264.7细胞培养板中,逆转录聚合酶链反应(RT-PCR)检测培养细胞TLR4 mRNA表达的变化,免疫荧光检测TLR4蛋白表达的变化,Western blot检测NF-κB表达的变化和酶联免疫吸附(ELISA)检测培养上清中TNF-α含量的变化。结果:ESBLs大肠埃希菌上调RAW264.7细胞TLR4 mRNA和蛋白的表达,NF-κB表达量增加,培养上清中TNF-α含量升高。黄芩苷能抑制大肠埃希菌对RAW264.7细胞TLR4 mRNA和蛋白的上调作用,降低NF-κB的活化,减少TNF-α的分泌,抑制作用呈现黄芩苷剂量依赖性。结论:黄芩苷对ESBLs大肠埃希菌体外直接抑菌作用虽然较弱,但可通过抑制TLR4及其介导的信号转导途径减少炎性因子的生成,从而发挥抗炎作用。
Objective： To investigate the effect and mechanism of baicalin against fl-lactamases Escherichia coli （ ESBLs E. coli） mediated by toll-like receptor 4 （TLR4） signal transduction pathway. Method： The RAW264. 7 cells monolayer pretreated with different concentration of baicalin were inoculated with ESBLs E. coli. The expression of TLR4 mRNA and protein were analyzed by semi-quantitative RT-PCR and Immunofluorescenee, respectively. The activity of NF-KB was detected by Western blot using total cellular protein. The production of TNF-ct in supernatant was determined by enzyme linked immunosorbnent assay （ELISA）. Result： ES- BLs E. coli significantly up-regulated the expression levels of TLR4 mRNA and protein in a time-dependent manner, induced the acti- vation of NF-κB in RAW264. 7, enhanced the production of TNF-ct in supernatant. Baicalin down-regulated the expression of TLR4 mRNA and protein, decreased the activation of NF-κB in RAW264. 7 cells and reduced the production of TNF-ot in supernatant in a dose-dependent manner. Conclusion： Baicailin could inhibit TLR4 signal transduction pathway. The mechanism of baicalin against ESBLs E. coli may be through inhibiting the expression of TLR4 and its signal transduction pathway.
出处
《中国中药杂志》
CAS
CSCD
北大核心
2013年第10期1590-1594,共5页
China Journal of Chinese Materia Medica
基金
安徽省自然科学基金项目(090413092)
安徽中医学院青年基金项目(2011qn032)
安徽省高等学校省级优秀青年人才基金项目(2012sqrl108)
