Effect of baicalin on expression of TLR4 in RAW264.7 cells infected by ESBLs Escherichia coli
Yun, Y.; Wang, C.-Z.; Gui, L.; Li, Z.-X.
Zhongguo Zhong Yao Za Zhi 38(10): 1590-1594
2013
ISSN/ISBN: 1001-5302 PMID: 23947144 Document Number: 669238
To investigate the effect and mechanism of baicalin against beta-lactamases Escherichia coli (ESBLs E. coli) mediated by toll-like receptor 4 (TLR4) signal transduction pathway. 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 Immunofluorescence, respectively. The activity of NF-kappaB was detected by Western blot using total cellular protein. The production of TNF-alpha in supernatant was determined by enzyme linked immunosorbnent assay (ELISA). ESBLs E. coli significantly up-regulated the expression levels of TLR4 mRNA and protein in a time-dependent manner, induced the activation of NF-KB in RAW264. 7, enhanced the production of TNF-alpha in supernatant. Baicalin down-regulated the expression of TLR4 mRNA and protein, decreased the activation of NF-KB in RAW264. 7 cells and reduced the production of TNF-alpha in supernatant in a dose-dependent manner. 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.