Effects of Chinese Herbal Compound on the Newcastle Disease Virus

[Objective]To explore the antiviral mechanisms of the Chinese herbal compound on Newcastle disease virus(NDV)and to provide a scientific basis for the reasonable usage of the antiviral drugs in clinic.[Method]The Chinese herbal compound was composed of Hedyotis diffusa,Lonicera japonica Thunb,Radix astragali and Glycyrrhiza uralensis.Then it was prepared to the Chinese herbal compound fluid extract with different concentrations.Its maximum no toxicity concentration and the tissue culture infective dose(TCID50)of NDV were respectively determined.There were normal cell control group,infected cell control group and treatment groups(different concentrations of the Chinese herbal compound).Different three methods were used for detecting the antiviral activities of the Chinese herbal compound.The OD value were determined by MTT[3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]method,and the therapeutic indexes were calculated to evaluate the antiviral effects.[Result]The maximum of no toxicity concentration of the Chinese herbal compound was 2-6 g/ml,and the TCID50 was 10-7.3.The minimum effective concentration of Chinese herbal compound using the first method was 2-10 g/ml,that of using the second method was 2-8 g/ml,and that of using third method was 2-7 g/ml.[Conclusion]The first method obtained the best antiviral effects,followed by the second method and the last was the third method,which indicated that the Chinese herbal compound not only kill the virus directly,but also inhibit the a certain process of the virus adsorption,penetration,replication and maturing.These provide a scientific basis for the reasonable usage of the antiviral drugs in clinic.