Astragaloside IV inhibits inflammation caused by influenza virus via reactive oxygen species/NOD‐like receptor thermal protein domain associated protein 3/Caspase‐1 signaling pathway

Abstract

Abstract Background Astragaloside IV (AS‐IV) is the most active monomer in the traditional Chinese herbal medicine Radix Astragali, which has a wide range of antiviral, anti‐inflammatory, and antifibrosis pharmacological effects, and shows protective effects in acute lung injury. Methods This study utilized the immunofluorescence, flow cytometry, enzyme‐linked immunosorbent assay, quantitative reverse transcription‐polymerase chain reaction, western blot, and hematoxylin and eosin staining methods to investigate the mechanism of AS‐IV in reducing viral pneumonia caused by influenza A virus in A549 cells and BALB/c mice. Results The results showed that AS‐IV suppressed reactive oxygen species production in influenza virus‐infected A549 cells in a dose‐dependent manner, and subsequently inhibited the activation of nucleotide‐binding oligomerization domain‐like receptor thermal protein domain associated protein 3 inflammasome and Caspase‐1, decreased interleukin (IL) ‐1β and IL‐18 secretion. In BALB/c mice infected with Poly (I:C), oral administration of AS‐IV can significantly reduce Poly (I:C)‐induced acute pneumonia and lung pathological injury. Conclusions AS‐IV alleviates the inflammatory response induced by influenza virus in vitro and lung flammation and structural damage caused by poly (I:C) in vivo.

Keywords

• astragaloside IV
• Caspase‐1
• inflammation
• influenza virus
• NOD‐like receptor thermal protein domain associated protein 3
• reactive oxygen species