Protective effects of Yinhuapinggan granule on mice with influenza viral pneumonia

Yinhuapinggan granule (YHPG), a Chinese medicine granule on the basis of Ma-Huang-Tang (Ephedra Decoction) and the clinical experience of Professor Wan Haitong, has been shown to inhibit the growth of influenza virus in vitro. The aim of this study was to investigate the protective effects of YHPG on mice with influenza viral pneumonia and its effects on regulating related inflammatory cytokines in influenza virus A-infected mice. ICR mice were inoculated intranasally with 15 LD50 viral dose of influenza virus A/PR/8/34 (H1N1) and treatments with YHPG (7.5, 15 and 30g/kg) were orally administrated daily for 5 consecutive days after challenge, respectively. The results showed that mortality rate, lung index, lung histopathological changes, IL-6 and TNF-α in serum were significantly attenuated in the treatment of YHPG (15 and 30g/kg) than those in the IFV control group, while the levels of IL-2 was significantly enhanced. Moreover, the RT-PCR results revealed that YHPG (15 and 30g/kg) significantly depressed the expressions of IL-1β, IFN-γ and TNF-α mRNA in lung tissues. Furthermore, the immunohistochemical staining results also revealed that the expression of NF-κB p65 proteins was downregulated when treated with YHPG (15 and 30g/kg). These results showed YHPG has protective effects on IFV-infected mice, due to its ability of alleviation of lung damage, regulation of the cytokine production via inhibiting the NF-κB p65 activation, attenuation of systemic and pulmonary inflammatory responses.