Spring climate is warm, suitable for the survival and propagation of bacteria, viruses and other microorganisms. Therefore, colds, flu, acute bronchitis, pneumonia, encephalopathy, measles, scarlet fever, mumps, and fulminant eye disease often occur at this time. Prevent and cure these spring frequently come on, in a lot of good medicine, banlangen can be regarded as more ideal medicine.

　　Radix isatidis contains indigo glycoside, B - sitosterol, amino acid, etc. The Chinese traditional medicine dictionary says that it can "clear heat, detoxify, cool blood." Treat influenza, epidemic cerebrospinal meningitis, je, pneumonia, pharynx is swollen, mumps, clattering, spots, "widely regarded for its utility.

　　The leaf of banlangen root, namely the big green leaf of traditional Chinese medicine, is also a good medicine for clearing heat and detoxifying, cooling blood and stopping bleeding, it has good therapeutic effect for diseases such as influenza, hepatitis, dysentery, pneumonia, gastroenteritis, oral ulcers, warts, etc.