Long Dan Cao (Radix Gentianae)

Long Dan Cao also known as Radix Gentianae is the root and rhizome of Gentiana. It is a relatively practical and common Chinese herbal medicine with a medicinal history of over 2,000 years.

Gentiana is a large genus of the gentian family and is an annual or perennial herb. There are more than 400 species in this genus, some of which are evergreen. Most of the plants of this genus are for ornamental use, and only some species have medicinal value.

The Long Dan Cao referred to herein is the root and rhizome of Gentiana manshurica, Gentiana triflora, Gentiana scabra or Gentiana rigescens.

Gentiana manshurica often grows in hillside grasslands or wet grasslands at an altitude of 100-1,100 meters. It is distributed in northern China and North Korea.

Gentiana triflora often grows on grasslands, wet grasslands, or forest edges at 640-950 meters above sea level. It can be found in the three eastern provinces of China, Inner Mongolia, Hebei, Russia, Japan, and North Korea.

Gentiana scabra often grows on hillside grasslands, thickets or forests at an altitude of 400-1,700 meters. It is distributed in China, Japan, Russia, and the United States.

Gentiana rigescens often grows in hillside grasslands, shrubs, or valleys at an altitude of 1,100-3,000 meters. It is native to Yunnan, Sichuan, Guizhou, Hunan, and Guangxi in China.

In spring and autumn each year, people gather the roots and rhizomes of Gentiana, wash them with water, dry them in the sun, cut them into segments, and make them into Chinese herbs.

Long Dan Cao contains gentiopicroside, swertiamarin, sweroside, amarogentin, amaroswerin, gentianine, gentioflavine, gentianidine, gentianal, and β-sitosterol. Generally, light yellow or yellowish-brown Long Dan Cao is the best.

According to <Shennong Ben Cao Jing>, the medicinal property of Long Dan Cao is relatively cold. It has a bitter taste similar to that of bile and has a certain therapeutic effect on the pathological changes of liver and gallbladder meridians.

In Chinese medicine, Long Dan Cao is often used to clear heat and dry dampness, purge liver fire and gallbladder fire, treat jaundice, convulsion, acute hepatitis, cholecystitis, otitis media, epidemic meningitis, epidemic Japanese encephalitis, urinary tract infection, and acute conjunctivitis.

There are more than 70 kinds of traditional Chinese medicine prescriptions containing Long Dan Cao, such as Long Dan Xie Gan Wan, Bai Dian Feng Jiao Nang, and Yindan Pinggan Capsules.

Health benefits of Long Dan Cao

  • Anti-inflammation, anti-tumor, and anti-plasmodium.
  • Inhibiting antibody production and delaying allergic reactions.
  • Inducing diuresis and promoting bile secretion.
  • Promoting the secretion of gastric juice and gastric acid, increase free hydrochloric acid, and improve appetite.
  • Reducing the damage of CCL4 or D-galactosamine to liver tissues and protecting the liver.
  • Relaxing muscles and relieve intestinal and uterine spasms.
  • Low doses of gentianine excite the central nervous system.
  • Large doses of gentianine inhibit the central nervous system and cause anesthesia.
  • It contains swertiamarin, which can inhibit the central nervous system and has analgesic and sedative effects.
  • Clearing damp-heat in lower energizer, treating jaundice caused by damp-heat in lower energizer.
  • Treating genital swelling and itching, eczema, yellow or odorous leucorrhea caused by the downward flow of damp-heat.
  • Clearing liver fire and gallbladder fire, treating headache, eye congestion, acute deafness, rib pain, and bitter mouth caused by the up-flaming of liver fire.
  • Treating high fever and convulsions caused by the exuberant liver heat or excessive heat generating wind.
  • Inhibiting Trichophyton gypsoides, Nocardia asteroides, Leptospira, Pseudomonas aeruginosa, Proteus, Typhoid bacilli, Dysentery bacilli, and Staphylococcus aureus.
  • The study found that large doses of gentianine can lower blood pressure, inhibit the heart, and slow heart rate.

Long Dan Cao is used with other Chinese herbs

Side effects of Long Dan Cao

Taking it in large doses may cause gastrointestinal reactions such as upper abdominal discomfort, nausea, vomiting, abdominal distension, diarrhea, etc. In severe cases, it may cause headaches, dizziness, and redness of the face.

Precautions of Long Dan Cao

  • The dosage of Long Dan Cao should be controlled between 3-6g.
  • It can be made into decoction or ground into powder for external use.
  • Pregnant women and children should not take it.
  • People with renal insufficiency should not take it.
  • People with deficiency-cold in spleen and stomach should not take it.
  • People with consumption of body-fluid from Yin deficiency should not take it.
  • People who impair body fluids due to Yin deficiency should not take it.