Study on Anti-virus Effect of Peptides from Isatis indigotica on the Mice Infected by Influenza Virus

OBJECTIVE:To study the anti-virus effect of peptides from Isatis indigotica on the mice infected with influenza virus. METHODS:Mice models of influenza virus infection were induced by nasal drops of 4LD50 influenza virus H1N1(A/PR8/34). Mice were divided into normal control group(constant volume of normal saline),model group(constant volume of normal saline),ribavirin group(i.p.,40 mg/kg,consecutive 7 days) and I. indigotica peptides high-dose,medium-dose and low-dose groups(i.g.,200,100,50 mg/kg,consecutive 14 days). The mortality,survival time,lung index,virus titer,the proliferation of T and B lymphocyte in mice were determined. RESULTS:Compared with normal control group,the mortality,lung index of mice in model group were increased significantly,while survival time,the proliferation of T and B lymphocyte was decreased significantly;there was statistical significance(P0.01). Compared with model group,the mortality,survival time and lung index on 5th day were decreased significantly in I. indigotica peptides high-dose and medium-dose groups;there was statistical significance(P 0.01 or P0.05);virus titer of I. indigotica peptides high-dose was decreased significantly on 3rd day;there was statistical significance(P0.05);T and B lymphocyte of I. indigotica peptides high-dose,medium-dose and low-dose groups were increased significantly;there was statistical significance(P0.01 or P0.05). CONCLUSIONS:I. indigotica peptides can obviously inhibit influenza virus in vivo and improve immune function.