Quercetin alleviates inflammation in acute bronchitis rats by inhibiting HMGB1/TLR4 signaling pathway
To investigate the effects of Quercetin(QUE)on inflammatory response and high mobility group protein B1/Toll like receptor 4(HMGB1/TLR4)signaling pathway in acute bronchitis(AB)rats,an AB rat model was constructed,and the successfully modeled rats were assigned into AB group,quercetin low and high dose groups(QUE-L,QUE-H groups),Quercetin high dose+HMGB1 recombinant protein group(QUE-H+r-HMGB1 group),with remaining normal healthy rats as control group.Wright's staining was applied to detect the number of inflammatory cells in the sediment of bronchoalveolar lavage fluid(BALF);ELISA was applied to detect the levels of inflammatory factors in BALF;flow cytometry was used to detect the levels of CD4+T,CD8+T and CD4+T/CD8+T in BALF;HE staining was applied to observe the pathological morphology of bronchial tissue and lung tissue;Western blot was applied to detect the expression of proteins related to the HMGB1/TLR4 signaling pathway.Compared with the control group,the AB group had increased secretion in the bronchial lumen,narrowed lumen,obvious infiltration of inflammatory cells in the wall,shedding and degeneration of bronchial mucosal epithelial cells,obvious thickening of smooth muscle layer,thickening of alveolar wall,widening of alveolar septum,and obvious infiltration of inflammatory cells,increased numbers of NEU,EOS,LYM,and elevated levels of TNF-α,IL-6,CD4+T,CD4+T/CD8+T,and increased expression of HMGB1,TLR4,p-NF-κB p65/NF-κB p65,while lower levels of IL-10 and CD8+T(P＜0.05).QUE(both low and high doses)could alleviate these changes mentioned above in AB rats(P＜0.05).As compared with QUE-H group,QUE-H+r-HMGB1 group demonstrated more severe pathological damage of bronchial and lung tissues,increased numbers of NEU,EOS and LYM,higher levels of TNF-α,IL-6,CD4+T and CD4+T/CD8+T,and higher expression of HMGB1,TLR4 and p-NF-κB p65/NF-κB p65 increased,while lower levels of IL-10 and CD8+T(P＜0.05).Taken together,quercetin can alleviate the inflammatory response in AB rats,and its mechanism of action is related to the inhibition of the HMGB/TLR4 signaling pathway.
QuercetinHigh mobility group protein B1/Toll-like receptor 4 signaling pathwayAcute bronchitisInflammatory response
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维普
