OBJECTIVE To investigate the protective effect of Shierwei Yishou San(SYS) against acute lung injury induced by influenza A(H1N1) virus, and to elucidate its potential molecular mechanism.

METHODS A total of 108 BALB/c mice were randomly divided into 6 groups, namely vehicle group, model group, low, medium, high dose SYS group, and positive group, with 18 mice in each group. Except for the vehicle group, mice in the other groups were infected intranasally with the H1N1-PR8 strain to establish the mouse model of acute lung injury induced by H1N1 virus infection. Mice in each administration group were intragastrically given low, medium and high doses of SYS as well as the positive drug oseltamivir phosphate. The pharmacodynamic efficacy of SYS against acute lung injury induced by H1N1 virus infection was evaluated by observing the survival rate, body weight changes, lung tissue viral load/titer, inflammatory response, and the degree of pathological damage. Network pharmacology was used to predict the potential mechanisms by which SYS alleviates H1N1 virus-induced lung injury, and lung tissue samples obtained from the above in vivo pharmacodynamic experiments were used to verify the expression levels of key genes and proteins in the relevant pathway.

RESULTS Pharmacodynamic experiments results revealed that SYS had a certain protective effect on the survival rate and body weight of H1N1 virus-infected mice, significantly inhibited viral replication in lung tissues, and alleviated inflammatory responses and pathological damage in mice. Network pharmacology prediction results suggested that the potential mechanisms of the four core medicinal herbs in SYS intervening H1N1 virus infection and subsequent lung injury was closely associated with the NLRP3 inflammasome-mediated pyroptosis pathway in the NOD-like receptor signaling pathway. Mechanistic studies demonstrated that SYS could suppress NF-κB activation, reduced the mRNA and protein expression of NLRP3, Caspase-1, and GSDMD, and inhibited Caspase-1 activation as well as the GSDMD protein cleavage mediated by activated Caspase-1.

CONCLUSION SYS can ameliorate H1N1 virus-induced acute lung injury in mice by inhibiting the NF-κB-mediated NLRP3 inflammasome/pyroptosis pathway.