Abstract
Porcine reproductive and respiratory syndrome (PRRS) is a highly contagious epidemic caused by the porcine reproductive and respiratory syndrome virus (PRRSV). Characterized by reproductive disorders in pregnant sows and respiratory symptoms in pigs of all ages, it poses a severe threat to the global swine industry. In recent years, the high mutation rate of PRRSV has increasingly limited the effectiveness of vaccines against it, prompting the search for new anti-PRRSV drugs. scutellarin (SCU), a natural flavonoid compound extracted from the medicinal plant Scutellaria baicalensis, possesses multiple biological activities. Its antiviral effects have been demonstrated in numerous studies; however, its inhibitory activity against PRRSV and the underlying mechanism remain unknown. In this study, through in vitro cell experiments, we found that scutellarin significantly inhibits PRRSV infection in PAMs. Furthermore, it directly acts on PRRSV to exert antiviral effects. Transcriptomic analysis suggests that scutellarin may exert its anti-PRRSV effects by regulating host immunity and anti-inflammation through immune-related signaling pathways, including the complement and coagulation cascades, ECM-receptor interaction, Rap1 signaling pathway, and PI3K-Akt signaling pathway.