ObjectiveTo explore the mechanism of Jiebiao Qingli decoction （JQD） in treating pneumonia caused by influenza A virus （IAV） infection.MethodsA total of 132 Balb/c mice were randomly assigned into normal control （NC）， model control （IAV）， oseltamivir （OSV， 37.5 mg·kg^-1）， and high-， medium-， low-dose JQD （H-， M-， and L-JQD： 6.05， 3.02， and 1.51 g·kg^-1， respectively） groups. The NC group was treated with normal saline nasal drops， and the other groups were intranasally inoculated with A/Brisbane/02/2018 （H1N1） ［pdm09-like virus （H1N1）］ for the modeling of IAV infection. Two hours post-modeling， the NC and IAV groups were administrated with normal saline by gavage， while other groups received corresponding drugs for 7 d. The body mass， survival status， and deaths of mice were recorded daily during the administration of the drugs. On days 3 and 7， the lung index was measured for mice in each group. Pathological changes in the lung tissue were observed via hematoxylin-eosin staining. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was conducted to measure the viral load （IAV-M） and the mRNA levels of Toll-like receptor 7 （TLR7）， p38 mitogen-activated protein kinase （p38 MAPK）， and nuclear factor-kappa B （NF-κB） in the lung tissue. Western blot was employed to measure the protein levels of p38 MAPK and NF-κB. Enzyme-linked immunosorbent assay was used to quantify serum levels of interleukin-2 （IL-2）， interleukin-6 （IL-6）， and tumor necrosis factor-alpha （TNF-α）.ResultsCompared with the NC group， the IAV group showed reduced survival quality and survival days （P<0.01）， lung congestion， inflammatory cell infiltration， elevated lung index （P<0.01）， increased viral load （P<0.01）， upregulated TLR7， p38 MAPK， and NF-κB levels （P<0.05， P<0.01）， decreased IL-2 level （P<0.01）， and elevated IL-6 and TNF-α levels （P<0.01）. Compared with the IAV group， H-JQD prolonged survival days （P<0.05）. All JQD groups alleviated pathological changes in the lung tissue and reduced the lung index （P<0.01）. M-JQD and H-JQD decreased the viral load （P<0.01）. H-JQD downregulated the mRNA levels of TLR7， p38 MAPK， and NF-κB （P<0.05， P<0.01） and the protein levels of p38 MAPK and NF-κB （P<0.01）， increased the serum IL-2 level （P<0.01）， and lowered the IL-6 and TNF-α levels （P<0.05， P<0.01）. M-JQD downregulated the mRNA level of NF-κB （P<0.01） and the protein level of p38 MAPK （P<0.05）， elevated the IL-2 level （P<0.01）， and lowered the TNF-α level （P<0.01）.ConclusionM- and H-JQD can prevent and control IAV infection-induced pneumonia dose-dependently by inhibiting the TLR7/MAPK/NF-κB signaling pathway， increasing IL-2， and reducing excessive secretion of IL-6 and TNF-α.

Jiebiao Qingli decoction;influenza A virus （IAV）;influenza;Toll-like receptor 7 （TLR7）/mitogen-activated protein kinase （MAPK）/nuclear factor-kappa B （NF-κB） signaling pathway;cytokines