Fig 4. Antioxidative effect of AS-IV. (A) Effects of AS-IV on TAC, SOD, GPX, CAT, and MDA in A549 cells infected with influenza virus. (B) Effects of AS-IV on ROS in A549 cells infected with influenza virus. The values are expressed as the mean ± SD. of three independent experiments. * P < 0.05, ** P< 0.01.
3.3. AS-IV inhibits the activation of the NLRP3/Caspase-1 signaling pathway induced by influenza infection
Former studies have shown that increased ROS can activate NLRP3 inflammasome-mediated cell damage[10], so we examined the expression levels of factors associated with the NLRP3/Caspase-1 signaling pathway in each group of cells. Our results showed that NLRP3 levels increased after influenza virus infection, but NLRP3 mRNA and protein levels decreased in a dose-dependent manner after AS-IV treatment (Fig. 5A, E-F). Moreover, compared with the IAV group, the activation of Caspase-1 in A549 cells after AS-IV treatment and the secretion of cytokines IL-18 and IL-1β were decreased (Fig. 5B-E, G-J).