The intervention effect of baicalein on colitis in mice through TLR4/NF-κB signaling pathway
SHAO Xiaoxiao1, WANG Weizhong2, MA Guolong1, JIN Yingli1, SHI Ruixin2, JIANG Yi1
1.Department of Gastroenterology, the Second Affiliated Hospital & Yuying Children’s Hospital, Wenzhou 325027, China; 2.The Second Clinical Medical College, Wenzhou Medical University, Wenzhou 325035, China
SHAO Xiaoxiao,WANG Weizhong,MA Guolong, et al. The intervention effect of baicalein on colitis in mice through TLR4/NF-κB signaling pathway[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2022, 52(11): 861-867.
Abstract：Objective: To investigate the effect of baicalein on experimental colitis induced by dextran sodium sulfate (DSS) through TLR4/NF-κB signaling pathway. Methods: Male mice of C57BL/6 strain were randomly divided into 5 groups: control group, colitis group, baicalein low-dose (BA-L) treatment group [10 mg/(kg·d)], baicalein high-dose (BA-H) treatment group [25 mg/(kg·d)] and 5-amino-salicylic acid (5-ASA) treatment group, with 12 mice in each group. Except for the control group, the other mice were given 3.5% DSS solution for 7 days to construct the experimental colitis model. Different doses of baicalein or 5-ASA were administered 7 days before DSS modeling and 7 days after DSS modeling, and the treatment lasted for 14 days. The average body weight, disease activity index (DAI) and colon histological activity degree score (HAI) were compared among all groups. The mRNA levels of IL-1β, TNF-α, IFN-γ, TLR4, NF-κB P65 and MyD88 in colon tissues of mice in each group were detected by real-time fluorescence quantitative PCR. The nucleation rate of NF-κB P65 in intestinal epithelial cells was determined by immunofluorescence. Results: Compared with the control group, mice in the colitis group developed severe colitis, which was manifested by decreased body weight, shortened total colon length, and significantly increased DAI and HAI (all P<0.01). And compared with the colitis group, the colitis of mice was significantly improved in BA-L group, BA-H group and 5-ASA group (all P<0.05). Besides, the mRNA expression levels of IFN-γ, TNF-α, IL-1β, MyD88, NF-κB p65 and TLR4 in colitis group were significantly higher than those in control group (all P<0.01). While the mRNA expression levels above in Ba-L group, BA-H group and 5-ASA group were significantly lower than those in the colitis group (all P<0.05). In addition, the nucleation rate of NF-κB p65 in intestinal epithelial cells of the colitis group was significantly higher than that of the control group (all P<0.001). While the nucleation rate of NF-κB P65 in Ba-L group, Ba-H group and 5-ASA group was significantly lower than that in the colitis group (all P<0.001).Conclusion: Baicalein may inhibit DSS-induced colon inflammation through TLR4/NF-κB signaling pathway in a dose-dependent manner.
