Effection of Six Chinese medicinal herbs on Activity of Newcastle disease virus

The effection of six extracts,which were from Isatis leaf, Isatis root, Houttuynia, Patrinia, Rhizoma Polygoni cuspidat, Sophora Flavescens Ait, on activity of NDV was investigated in chicken embryos.To study the action of six extracts on NDV, three ways were adopted which were adding medicine and virus after acted for a while,inoculating virus after adding medicine, inoculating virus before adding medicine. Isatis root, Patrinia, Houttuynia exhibited stronger effect on NDV. One of Isatis root, Patrinia, Houttuynia can be studied as principal agent. It provided a theoretic basis for screening out the substance with high anti-NDV activity and clinical prevention and treatment of ND.