Figure 1. Hesperidin and kaempferol cause the opposite effects on influenza virus replication and antiviral state in the infected MDCK and A549 cells.

(A) MDCK cells were infected with influenza A/WSN/33 viruses at MOI of 0.001 for 3 h, and then incubated with 100 μM of hesperidin or kaempferol for another 48 h, the cells were harvested and virus titer of each treatment was measured by TCID₅₀ method. A549 cells were infected by Influenza A/WSN/33 virus for 3 h, and then treated with hesperidin or kaempferol for 24 h, 0.05% DMSO as a control (PC). Cellular viral RNA (vRNA) level was examined by analyzing NP gene expression using Q-PCR (B), cellular influenza virus proteins NP and NS1 were detected by western blot (C), full-length blots are presented in Supplementary Figure 15. Anti-viral state associated genes expression in the infected A549 cells (D) and uninfected A549 cells (E). These genes, including interferon α (IFNα), interferon β (IFNβ) and interferon γ (IFNγ), monocyte chemotactic protein 1 (MCP1), regulated on activation, normal T cell expressed and secreted (RANTES) and interferon-inducible protein 10 (IP10) were determined by Q-PCR. Results were presented as means ± SEM of three independent experiments,*p < 0.05; **p < 0.01; ***p < 0.001, compared with untreated cell, mRNA expression of each target gene was normalized to GAPDH mRNA expression. H represented hesperidin; K represented kaempferol; 0.05% DMSO as a control (NC).