Artemisia annua L. leaf extracts suppress influenza virus infection by targeting the viral nucleoprotein and blocking mitochondria-mediated apoptosis.

Artemisia annua L. is a medicinal herb with multiple therapeutic applications, whereas its anti-influenza A virus (IAV) efficiency and mechanism of action are still unclear. Here, we investigated the inhibition activity and mechanism of A. annua leaf methanol extracts (AALME) against IAV in vitro and in vivo. Our results revealed that AALME exhibits potent anti-IAV activity by interacting with IAV particles. Mechanistically, AALME directly targets the IAV nucleoprotein (NP) protein and abolishes the nuclear import of IAV NP. AALME profoundly suppresses IAV-induced mitochondrial apoptosis via suppressing ROS-mediated AIF-dependent pathways. More importantly, we found that AALME plays a crucial role in protecting mice from IAV infection and mitigating IAV pathogenicity. This current work provides mechanistic insight into the mechanism by which AALME controls IAV infection in vitro and in vivo, potentially contributing to the development of antiviral treatments for IAV infection.