FeiyanHeji multifunctionally inhibits Influenza Virus via PA Protein Degradation and RIG- I Signaling Pathway Potentiation

Influenza virus infection can lead to high mortality and severe disease complicated by secondary bacterial pneumonia. FeiyanHeji (FyHj) is a traditional Chinese medicine (TCM) mixture used clinically to treat pneumonia caused by influenza, although its mechanism of action remains unclear. We first conducted a network pharmacology analysis of the ten components in FyHj to predict their potential interactions with influenza-related targets. GO and KEGG analyses revealed significant enrichment in the inflammatory response, ubiquitin protein binding, RNA virus-related pathways, and the RIG-I signaling pathway, suggesting these may be involved in the anti-influenza process. Further experimental validation demonstrated that FyHj inhibits viral replication through two mechanisms: (1) promoting the degradation of polymerase acidic (PA) protein by interfering with UBP11-mediated K48-linked deubiquitination, and (2) enhancing antiviral innate immunity by upregulating the RIG-I/MAVS signaling pathway and stabilizing MAVS through inhibition of TRIM25-mediated K48-linked ubiquitination of MAVS. Finally, FyHj was observed to reduce lung viral load and inflammation in mice infected with influenza A virus (IAV). In conclusion, FyHj decoction elicits potent antiviral effects through multiple mechanisms, providing a mechanistic basis for the clinical application of FyHj and highlighting its potential as a source for multi-target anti-influenza therapies.