What Is Long Dan Cao
Long Dan Cao also known as Radix Gentianae is the root and rhizome of Gentiana manshurica, G. triflora, G. scabra, or G. rigescens, which is a perennial herb belonging to the family Gentianaceae. It is a relatively practical and common Chinese herbal medicine, which first appeared in <Shennong Ben Cao Jing> in the late Western Han Dynasty (about 100 BC).
There are about 334 species of Gentian, which are distributed in the high mountains of temperate regions. Among them, some species are annual herbs. Most of the plants in this genus are for ornamental use, and only some species are used for medicinal purposes.
Gentiana manshurica are hardy and like cold weather. They often grow on hillside grasslands, wet grasslands, or roadsides 100-1,100 meters above sea level. They can be found in China and North Korea.
G. triflora often grows on grasslands, wet grasslands, or under forests at an altitude of 640-950 meters. They can be found in Inner Mongolia, Hebei, and the three northeast provinces of China, Russia, Japan, and Korea.
G. scabra often grows on hillsides, grasslands, roadsides, river beaches, shrubs, or forest edges at an altitude of 400-1,700 meters. They are distributed in China, Russia, North Korea, and Japan.
G. rigescens is a plant endemic to China. They are mainly distributed in hillside grasslands, shrubs, and under forests on the Yunnan-Guizhou Plateau in China. Currently, they have not been introduced and cultivated artificially.
In spring and autumn every year, people gather the roots and rhizomes of Gentiana manshurica, G. triflora, G. scabra, or G. rigescens, wash them with water, remove impurities, dry them in the sun, cut them into sections, and make them into Chinese herbal medicines.
Long Dan Cao contains gentiopicrin, gentioline, swertiamarin, swertianolin, loganic acid, secoxyloganin, isoorientin, isovitexin, kaempferol, trilobatin, quercetin, chromone, ursolic aldehyde, ethyl gallate, salicylic acid, stigmasterol, ursolic acid, oleanolic acid, gentioflavine, gentianose, gentianidine, and gentianol.
Generally, yellow-brown or dark-brown Long Dan Cao with yellow-white or brown-yellow cross-section and light yellow wood hearts is preferred.
According to <Shennong Ben Cao Jing>, the medicinal property of Long Dan Cao is relatively cold with a bitter taste. It has a certain therapeutic effect on the pathological changes of the liver and gallbladder meridians.
In traditional Chinese medicine (TCM), it is often used to clear heat and dry dampness, purge liver fire and gallbladder fire, and treat acute jaundice hepatitis, acute conjunctivitis, asthenospermia, herpes zoster, postherpetic neuralgia, anal eczema, anal fissure, hemorrhoids, and early perianal abscess.
There are more than 70 kinds of traditional Chinese medicine prescriptions containing it, such as Long Dan Xie Gan Wan, Bai Dian Feng Jiao Nang, and Yindan Pinggan Capsules.
- Anti-inflammation, inhibiting mouse ear swelling induced by xylene or croton oil.
- Promoting bile secretion and gallbladder contraction, stimulating gastric acid and gastric juice secretion, and improving appetite.
- Inhibiting the acute hepatocyte necrosis caused by CCL4 or D-galactosamine and protecting the liver.
- Large doses of gentioline can lower blood pressure, inhibit the heart, and slow down the heart rate.
- Clearing damp-heat in lower energizer, treating jaundice caused by damp-heat
- Treating genital swelling and itching, eczema, yellow or odorous leucorrhea caused by the downward flow of damp-heat.
- Clearing excessive fire in liver and gallbladder, 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 excessive heat in liver meridian or excessive heat generating wind.
- Inhibiting human lung cancer cell A549, human liver cancer cell HepG2, human epithelial ovarian cancer cell HO8910, and human ovarian cancer SKOV3.
- Inhibiting Pseudomonas aeruginosa, Proteus, Typhi, Trichophyton gypsum, Nocardia Stellaria, and Leptospira.
- Its water extract can inhibit the respiratory syncytial virus.
- Gentiopicrin can reduce the content of lipid droplets and triglycerides in 3T3-L1 cells. In vivo experiments have also shown that oral gentiopicrin can reduce the weight and visceral fat mass of mice.
- Studies have found that gentiopicrin can inhibit the transcription of G6PC and PEPCK, and inhibit the transcriptional activity of FOXO1 by inducing the phosphorylation of AKT of Ser473, thereby reducing high-quality diet-induced hyperglycemia in mice.
- It can be used in combination with Gui Zhi (Ramulus Cinnamomi), Yi Yi Ren (Semen Coicis), Niu Xi (Radix Achyranthis Bidentatae), Chen Pi (Tangerine Peel), and Sheng Jiang (Rhizoma Zingiberis Recens) to treat joint effusion.
- It can be used in combination with Dan Shen (Radix et Rhizoma Salviae Miltiorrhizae), Chuan Xiong (Rhizoma Chuanxiong), and Da Huang (Radix et Rhizoma Rhei) to treat constipation and herpes zoster.
- It can be used in combination with Niu Huang (Calculus Bovis), Qing Dai (Indigo Naturalis), and Huang Lian (Rhizoma Coptidis) to treat high fever and convulsions caused by the excessive heat in liver meridian or excessive heat generating wind.
- It can be used in combination with Zhi Zi (Fructus Gardeniae), Chai Hu (Radix Bupleuri), and Huang Qin (Radix Scutellariae) to treat headaches, eye congestion, acute deafness, rib pain, and bitter mouth caused by the up-flaming of liver fire.
- It can be used in combination with Ze Xie (Rhizoma Alismatis), Mu Tong (Caulis Akebiae), and Che Qian Cao (Plantago Asiatica) to treat genital swelling and itching, eczema, yellow or odorous leucorrhea caused by the downward flow of damp-heat.
At present, there is no data showing that it has toxic effects, and there are no reports of serious adverse reactions when it is taken in accordance with the prescribed dose.
Precautions and Warnings
- The dosage of Long Dan Cao should be controlled between 3-6g.
- It can be made into decoctions or ground into powder for external use.
- People who are allergic to Long Dan Cao should not take it.
- It should not be taken at the same time as Sheng Di Huang (Radix Rehmanniae).
- People with deficiency-cold in the spleen and stomach should not take it.
- People with consumption of body-fluid due to yin deficiency should not take it.
- Pregnant women, children, and the elderly should not take it.