Effect and mechanism of Reduning injection on influenza A virus / 药学学报

The purpose of this study is to investigate the effect of Reduning injection (RI) on influenza A virus (IAV) and its mechanism. We evaluated the cytotoxicity of RI in A549 and MDCK cells by cell counting kit-8 (CCK-8) assay. Western blot and cytopathic effect (CPE) assays were applied to test the effects of RI on viral protein, CPE and virus virulence to evaluate its inhibitory effect. The proteins level of heme oxygenase 1 (HO-1), nuclear factor erythroid 2-related factor 2 (Nrf2), phosphorylation of P38 mitogen-activated protein kinases (MAPK) and extracellular signal-regulated kinases 1/2 (ERK1/2) were detected by Western blot. Real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the RNA expression of interferon-α/β (IFN-α/β). The relative luciferase reporter assay was used to analyze the promoter activity and transcriptional regulation of Nrf2. The results indicated that RI inhibited IAV-induced MDCK cytopathies in a dose-dependent manner, decreased M2 protein of influenza virus and viral titer, indicating that it has definite effect on inhibiting IAV. RI promotes the phosphorylation of P38 MAPK and ERK1/2, activates the activity of Nrf2 nuclear transcription factor, increases the expression of Nrf2 protein in the nucleus, thus up-regulates the expression of HO-1 protein, and ultimately increases the IFN-α/β mRNA level. In summary, our results demonstrated that RI inhibits the replication of IAV by activating MAPK/Nrf2/HO-1 signaling pathway, revealing a new mechanism of RI against influenza virus, and providing theoretical basis for clinical treatment of influenza virus.

Effect of compound houttuynia mixture on influenza virus in vitro / 药学学报

Compound houttuynia mixture belongs to OTC class A medicine, which is made from Houttuynia cordata, Scutellaria baicalensis, Radix Isatidis, Forsythia, and Lonicera. As a kind of compound preparation of traditional Chinese medicine, houttuynia cordata mixture has extensive pharmacological effects, for example, clearing away heat and detoxifying, thus it is used for the sore throat, acute pharyngitis, and tonsillitis with wind-heat syndrome. In this study, the antiviral activity against influenza viruses and the primary mechanism of compound houttuynia mixture was evaluated. The antiviral effect of compound houttuynia mixture was determined by cytopathic effects (CPE), Western blot, quantitive reverse transcription PCR (qRT-PCR), and virus titer assays. The effect of houttuynia mixture on the replication cycle of influenza virus was evaluated by time-of-addition assay. In conclusion, the results showed that the compound houttuynia mixture had a broad-spectrum effect against influenza virus, including the international common influenza virus strains, the drug-resistant strains and the highly pathogenic avian influenza viruses H5N1 and H7N9. It mainly impairs the early stage of the viral replication.