Screening Of Anti-NDV Traditional Chinese Medicine Prescription And A Preliminary Study On The Antiviral Mechanism

Newcastle disease is an acute,febrile and highly contagious disease caused by Newcastle disease virus (NDV),with high incidence and fatality rate, and is one of the major infectious diseases of poultry industry, OIE classified it as classA disease, and bring huge loss to poultry industry. Although vaccination is the most common preventive measures, but the immune chickens infecting ND brings serious challenges for the prevention of Newcastle disease, thus, current application research was focus on antiviral medicine, espically antiviral traditional Chinese medicine with lower drug residues. Recent studies showed that many Chinese herbal medicine and its components had antiviral activity,so screening the anti-NDV traditional Chinese medicine ingredients,and making use of compatibility to form prescription, screening the prescriptions with stronger anti-NDV effect, and studying the antiviral mechanism has important significance to the prevention and treatment of Newcastle disease.In this study, we used cell culture and MTT method to screen the traditional Chinese medicine ingredients in Baicalin, oxymatrine, Panax Notoginsenosidum, coptis root berberine, chrysanthemum flavone, chlorogenic acid, isatis root polysaccharide, astragalus polysaccharide, isatis root alkaloid and epimedium polysaccharide which were all in safety concentrations, in order to evaluate the anti-NDV ability. The results showed that the majority of Chinese medicine ingredients could inhibit the viral infectivity, and baicalin, oxymatrine, Panax Notoginsenosidum and chrysanthemum flavone inhibited stronger.To make use of compatibility to form prescription which had stonger anti-NDV activity, firstly, according to a certain proportion,10 traditional Chinese medicine formulae were formed by three kinds of Chinese medicinal ingredients which were selected from Panax Notoginsenosidum, chrysanthemum flavone, baicalin, oxymatrine, isatis root alkaloid, astragalus polysaccharide and isatis root polysaccharide, then conducted the anti-vival screening tese. The results showed that formula 1,5,6,7,9,10 had better antiviral activity, furthermore, the different modes of administration and drug concentrations had a certain effect on the antiviral ability.Though DF1 cell culture we found 6 formulae which have strong effect against Newcastle disease virus, in order to further verify the antiviral effect in vivo, we use chicken embryo inoculation determination of hemagglutination agglutination hemagglutination agglutination value to verify it. The results showed that hemagglutination agglutination value of the experimental group was significantly lower than that of virus control group, at the same time,the differences camparing with the single ingredients at the same concentration shawed significantly or very significantly, it suggested the formula not only had good the antiviral effect, but also had the stronger antiviral effect than single ingredients. Therefore, the different modes of administration and the concentration of the formulae could influence the antiviral ability.For further study on mechanism of traditional Chinese Medicine formula against Newcastle disease virus, using MTT method and ELISA method, we determined the effect of 6 Chinese medicinal formula on chicken peripheral blood lymphocyte proliferation and the secretion of IL-2, IFN-γ cytokine. The results showed that the 6 formulas in varying degree promote lymphocyte proliferation and the effect is affected by different concentrations. In addition,6 formulas can promote the secretion of IL-2 lymphocytes, IFN-γ, but is the effects were affected by the concentration of prescription.