Antiviral effects of Yinhuapinggan granule against influenza virus infection in the ICR mice model

Yinhuapinggan granule (YHPG), a Chinese medicine granule based on Ma-Huang-Tang (Ephedra Decoction) and the clinical experience of Professor Wan Haitong, is used in traditional Chinese medicine (TCM) for the treatment of colds, influenza, fever, inflammation and cough. This study investigated the antiviral effects of YHPG on the production of inflammatory cytokines in influenza virus (IFV)-infected mice and evaluated the effect of YHPG on the expression of NF-κB p65 and the level of key signaling molecules in the TLR4 signaling pathway. ICR mice were orally administrated YHPG at doses of 7.5, 15 and 30 g kg−1 day−1 for 2 or 6 days after IFV infection. On days 3 and 7 after infection, YHPG (15 g/kg and 30 g/kg) significantly increased levels of interleukin (IL)-2 and interferon gamma and decreased levels of IL-4, IL-5 and tumor necrosis factor (TNF) in serum compared with the IFV control group. Furthermore, the expression of TLR4, MyD88, TRAF6 and NF-κB p65 at the mRNA and protein level was significantly lower in the YHPG (15 and 30 g/kg) treatment groups than in the IFV control group. These results suggest that YHPG has antiviral effects in IFV-infected mice, which is associated with the inhibition of the TLR4−MyD88−TRAF6 signaling pathway and the expression of NF-κB p65.