Ban Lan Gen (Radix Isatidis)

What Is Ban Lan Gen

Ban Lan Gen also known as Radix Isatidis is the root of Isatis Indigotica, which is a biennial herb belonging to the family Cruciferae. It is a relatively practical and common Chinese herbal medicine, which first appeared in <Tang Ben Cao> in 659 AD.

This plant is used medicinally. Its leaves can also be made into Chinese herbal medicine, which is called Da Qing Ye (Folium Isatidis).

In southern China, the roots and rhizomes of Strobilanthes cusia are also known as Ban Lan Gen. Its effect is similar to that of Radix Isatidis.

Isatis Indigotica

In the fall of every year, people gather the roots of Isatis indigotica, wash them with water, remove their impurities, cut them into slices, dry them in the sun, and make them into Chinese herbal medicines.

Ban Lan Gen contains indigotin, indirubin, isaindigodione, 3-hydroxyphenyl quinazolone, tryptanthrin, 2,4,(1H,3H)-quinazol dione, isaindigotone, sinigrin, palmitic acid, mustard Acid, fragrant acid, linoleic acid, maleic acid, benzoic acid, anthranilic acid, amino acids, β-sitosterol, γ-sitosterol, quinoline compounds, adenosine, polysaccharides, emodin, and pyrophaeophorbide.

Generally, light grayish-yellow or light brownish yellow Ban Lan Gen with yellow wood parts is preferred.

According to <Fen Lei Cao Yao Xing>, the medicinal property of Ban Lan Gen is relatively cold, with a bitter taste. It has a certain therapeutic effect on the pathological changes of the heart and stomach meridians.

The medicinal property of Ban Lan Gen is similar to that of Da Qing Ye (Folium Isatidis) and Qing Dai (Indigo Naturalis).

In traditional Chinese medicine, Ban Lan Gen is often used to clear heat and remove toxins, cool blood and relieve sore throat, treat upper respiratory tract infections, acute laryngitis, tonsillitis, acute hepatitis, enteritis, influenza, epidemic cerebrospinal meningitis, Japanese encephalitis Erysipelas, condyloma acuminatum, infectious mononucleosis, acute conjunctivitis, and keratitis.

There are about 100 kinds of traditional Chinese medicine prescriptions containing Ban Lan Gen, such as Banlangen Keli, Lianhua Qingwen capsule, and Zhong Gan Qing Pian.


  • Anti-oxidation, scavenging superoxide anion, and hydroxyl radical.
  • Inhibiting influenza virus, Japanese encephalitis virus, mumps virus, arboviruses.
  • Improving immunity and inhibiting platelet aggregation induced by ADP.
  • Reducing the damage of CCL4 to liver tissue and protecting the liver.
  • Reducing serum cholesterol, triglycerides, and myocardial oxygen consumption.
  • Dispelling wind and heat, treating fever, headache, sore throat caused by wind-heat.
  • Clearing excess-fire in heart and stomach, treating fever, headache, thirst, and sore throat in the early stage of warm diseases.
  • Treating macules and purplish tongue caused by warm diseases.
  • Removing heat toxins, treating erysipelas, sores, and carbuncles.
  • Inhibiting bacillus subtilis, Staphylococcus aureus, Escherichia coli, typhoid bacilli, and dysentery bacilli.
  • Indirubin is an effective drug for the treatment of chronic myeloid leukemia. Both it and its derivatives can promote the apoptosis of tumor cells.


Side Effects

It has been reported that oral Ban Lan Gen may cause digestive system symptoms or hemolytic reactions.

Overdose of it may cause loss of appetite, abdominal pain, diarrhea, and bloating.

Its injection may cause allergic reactions, such as urticaria, erythema multiforme, atopic dermatitis, multiple granulomas, or anaphylactic shock.

Precautions and Warnings

  • The dosage of Ban Lan Gen should be controlled at 9-15g.
  • It is recommended to reduce the dosage when children take it.
  • It can be made into decoctions, tea, powders, or injections.
  • People who are allergic to Ban Lan Gen should not take it.
  • People with no syndromes of excess heat should not take it.
  • People with deficiency-cold in the spleen and stomach should not take it.
  • Pregnant women should not take it.