Protective effects of Yinhuapinggan granule on mice with influenza viral pneumonia

• YHPG significantly reduced mortality, prolonged life span and increased the survival time of infected mice.
• YHPG significantly decreased the lung index and ameliorate the lung damage compared with IFV-infected mice.
• YHPG reduced the inflammatory responses by regulating the cytokines expression.
• YHPG inhibited the expression of NF-κB p65 proteins in the lung tissues induced by influenza virus.

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 30 g/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 30 g/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 30 g/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 30 g/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.