The impact of Baicalin on influenza virus gene replication and oxidative-stress damage

Influenza A virus targets the lung epithelial cells for infection and produces clinical outcomes ranging from a mild upper respiratory infection to severe pneumonia. Baicalin is Chinese herbal monomer of phenolic hydroxyl flavonoids extracted from scutellaria baicalensis of heat-clearing and detoxicating drug, has better anti-inflammatory function, antioxidant function and antiviral activity, but the mechanism of the anti-influenza viral activity of baicalin has not been revealed. The research object of the study is to discuss the significant activity and part mechanism of baicalin against influenza A viruses. Antiviral efficiency of baicalin in vitro was observed with trypan blue staining method. RT-PCR was used to study the impact of baicalin on influenza A virus structural protein HA, NA, M gene replication. Intracellular generation of reactive oxygen species (ROS) was examined by flow cytometry using probe DCFH-DA. Antioxidant reagent kits were applied to detect Superoxide dismutase (SOD) activity, malondialdehyde (MDA) content. The results showed that baicalin has a better protective effect on cell damage from influenza A virus. Compared to virus infected group, HA, NA, M gene replication in high concentration baicalin (50 mu g/ml) treatment group was in a decreasing trend respectively, but there has no significant difference. Baicalin can reduce influenza virus-induced ROS production in a dose-dependent manner, and decrease the production of malondialdehyde (MDA)ythe end product of lipid peroxidationyimprove the activity of antioxidant enzyme SOD, and so reduce influenza virus infection-induced oxidative-stress damage.