Astragaloside IV inhibits inflammation caused by influenza virus via ROS/NLRP3/Caspase-1 signaling pathway

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 anti-fibrosis pharmacological effects, and shows protective effect in acute lung injury. This study utilized the immunofluorescence, flow cytometry, ELISA, RT-qPCR, Western blot and Hematoxylin and eosin(H&E) staining methods to investigate the mechanism of AS-IV in reducing viral pneumonia caused by influenza A virus (IAV) in A549 cells and BALB/c mice. The results showed that AS-IV suppressed ROS production in influenza virus-infected A549 cells in a dose-dependent manner, and subsequently inhibited the activation of NLRP3 inflammasome and Caspase-1, decreased 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. Which provides a new therapeutic strategy for influenza virus infection.