Cross‑kingdom antiviral action of Scutellaria baicalensis Georgi and Chrysanthemum indicum L. miRNAs: A novel strategy against duck viral hepatitis.

Duck viral hepatitis (DVH) requires novel therapeutic strategies. This study investigated antiviral miRNAs in separate decoctions of Scutellaria baicalensis Georgi and Chrysanthemum indicum L. High-throughput sequencing identified 14 highly expressed miRNAs, which were chemically synthesized for functional validation. CCK8 assay quantified cytoprotection in duck embryonic hepatocytes (DEHs) and RT-qPCR measured DHAV-1 gene expression, enabling the selection of the most effective miRNAs. Two candidates, novel-miR2 (from S. baicalensis) and novel-miR10 (from C. indicum), were selected for detailed study. RT-qPCR along with fluorescent probes assessed miRNA concentrations, stability, and their effects on DEHs biological characteristics. In vivo evaluations included mortality rates, liver histopathology/function, and markers of inflammation/apoptosis. Both miRNAs exhibited differential concentrations in fresh versus dried herbs and demonstrated good thermal stability. In vitro, miRNAs reduced DHAV-1 replication, apoptosis, necrosis, and ROS, while enhancing cell viability. Oral administration improved survival rates in infected ducklings, lowered serum liver enzymes, and alleviated hepatic damage. Specifically, novel-miR2 predominantly reduced apoptosis, whereas novel-miR10 alleviated inflammation. Collectively, novel-miR2 and novel-miR10 suppressed DHAV-1-induced hepatitis, exerting hepatoprotective effects. These findings provided new evidence for clarifying the active constituents of herbal decoctions and their miRNA‑mediated cross‑kingdom antiviral mechanism.