Radix Isatidis (indigowoad root), as the Traditional Chinese Medicine (TCM), is a kind of dried root of the plant Isatidis indigotica Fort (family Cruciferae), and is officially listed in the Chinese Pharmacopoeia.
It is mainly distributed in Hebei, JiangXi,Zhejiang, Fujian, Anhui and Gansu provinces in China. It has been used as a medicinal plant for more than 2000 years from Shen Nong Ben Cao-Jing, a famous ancient Chinese medicinal literary.
It has a widely useful activities including anti-virus, anti-bacterial, anti-endotoxic, anti-inflammatory, and immune regulatory effects. Because the chemical constituents with anti-bacterial effect of Radix Isatidis remain uncertain, the reasons for its actions have remained a puzzle for a long time. Some researchers considered that the extract of Radix Isatidis had high anti-virus effects.