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Objectivte: To study the preventive and therapeutic effects of Aromatic Chinese herbs(ACH) on IFV-infected Madin-Darby canine kidney (MDCK) cells and IFV-infected mice.Methods: The antiviral activity of nontoxic-level ACH against IFV A/FM/1/47 was examined by assaying (neutralization assay) its inhibition of the IFV-induced cytopathic effects.The mode of ACH action was examined with a time-of-addition assay of synchronized infections, followed by viral attachment and penetration assays.MTT assay was used to evaluate median inhibitory concentration (EC50) and therapeutic index (TI).In addition, lung virus titers, lung index, lung histology, IFV load in lung, and the effect of ACH on pathogen recognition receptors of tracheal mucosa were detected.The inhibition of viral replication was demonstrated by quantitative real-time PCR, pathology technique and cell culture technique.Results: ACH ≥ 19.31μg/mL caused microscopically detectable alterations in cell morphology (including cellular atrophy, vacuolization, and cell detachment).ACH treatment before viral inoculation had an IC50 of 5.89 μ g/ml and TI of 3.28.ACH treatment upon viral inoculation had IC50 of 9.56μg/ml and TI of 2.02.ACH treatment after viral inoculation failed to inhibit virus and had TI less than 0.05.The preventive treatment with ACH in vivo against IFV was examined.ACH was administered through intranasal or aerosol route once per day for 7 days to BALB/c mice before infection and continued for 4 days after infection.ACH can effectively treat pneumonia caused by H1N1 infection in mice.Aerosol ACH and intranasal ACH showed inhibition rate of lung of 32.29% vs.25.46%, mean lung index of 1.09 vs.1.20, mean lung score of 3.2 vs.3.5, and mean lung virus titer of 5.6 vs.6.0.The lung virus titers, lung index, lung lesion scores and lung virol load of ACH (intranasal and aerosol administration) were significantly lower (p<0.01-0.05).The over-reaction of the immune response induced severe alveolitis with marked infiltration of neutrophiles in the bronchiolar and pneumonia with intense exudates in bronchial lumen in the control mice, and intranasal and aerosol administration of ACH to infected mice were highly effective in preventing death and inhibiting pneumonia.Intranasal ACH significantly suppressed the rnRNA expressions of TLR2, TLR4, and MyD88, indicating it could prevent and control the over-activation of innate immune.These results indicated that TLR2 and TLR4 may play an important role in responding to IFV infection.Conclusions: Our results give scientific support to the use of preventive treatment with ACH against influenza virus.ACH (intranasal and aerosol route) has potential utility in preventing and controlling seasonal pandemics of influenza virus infections.