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

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) -1ß and IL-18 secretion. In BALB/c mice infected with Poly (IC), oral administration of AS-IV can significantly reduce Poly (IC)-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 (IC) in vivo.