Extracts prepared from Ginkgo bibioba, Ficus carica, Isatis indigotica, and Rheum officinale exhibit over 50% antiviral activity, and that of Ficus carica is up to 68.6%.

• 其中银杏、无花果、板兰根、大黄对烟草花叶病毒的抑制率在50%25以上，无花果最高，达到68.；6%25。