黄芩苷通过TLR4/NF-κB通路调控LPS诱导的大鼠肠黏膜微血管内皮细胞分泌炎性因子研究

Effects of baicalin on LPS induced secretion of inflammatory factors in rat intestinal mucosa microvascular endothelial cells via TLR4/NF-κB pathway

为了探讨黄芩苷对脂多糖（LPS）引起的大鼠肠黏膜微血管内皮细胞（RIMMVECs）分泌炎性因子肿瘤坏死因子（TNF-α）、白细胞介素-1β（IL-1β）和白细胞介素-6（IL-6）的影响及其机制,试验将第3代RIMMVECs细胞分为5组,即空白对照组、造模组、高浓度药物组、中浓度药物组和低浓度药物组,用LPS刺激细胞造模,各药物组的细胞在给予LPS前先用不同浓度黄芩苷预处理,然后以ELISA方法检测其细胞上清液中TNF-α、IL-1β、IL-6表达水平,并用Western-blot方法检测各组细胞Toll样受体4（TLR4）、核转录因子κB（NF-κB）和磷酸化核转录因子κB（p-NF-κB）蛋白表达量。结果表明：与空白对照组相比,3个浓度药物组RIMMVECs受LPS刺激后分泌的TNF-α、IL-1β和IL-6显著降低,同时黄芩苷预处理可抑制TLR4的表达和NF-κB的磷酸化。说明黄芩苷通过调控TLR4/NF-κB信号通路可抑制炎性因子的分泌。

The aim of the present study was to investigate the mechanism of baicalin on lipopolysaccharide（LPS） induced inflammatory cytokines secretion in rat intestinalmucosa microvascular endothelial cells（RIMMVECs）, such as tumor necrosis factor（TNF-α）, interleukin-1β（IL-1β） and interleukin-6（IL-6）.The third passage RIMMVECs were divided into five groups： blank control group, model group, high concentration drug group, medium concentration drug group and low concentration drug group.Cells in each drug group were pretreated with different concentrations of baicalin and stimulated with LPS.The expression levels of TNF-α, IL-1β and IL-6 in the supernatant of the cells were detected by ELISA, and the expressions of Toll-like receptor 4（TLR4）, nuclear factor κB（NF-κB） and phosphorylated nuclear factor-κB（p-NF-κB） were detected by Western-blot.The results showed that the secretion of TNF-α, IL-1β and IL-6 in RIMMVECs stimulated by LPS in the three drug groupswere significantly lower than those in the control group, and TLR4 expression and NF-κB phosphorylationcould be inhibitedby using baicalinpretreatment.These results suggest that baicalin can inhibit the secretion of inflammatory factors by regulating TLR4/NF-κB signaling pathway.