1. Aliases

Guangdong Banlangen, Malalangen, Banlangen, and Indigo indigotica.
2. Plant morphology
Perennial herbs. The base of the stem is slightly lignified, with many branches, obvious stem nodes, and tender branches covered with brown fine soft hairs. The leaves are opposite, ranging from inverted oval shaped to oval shaped, with the apex gradually pointed and the base gradually narrowed. The edges are shallow serrated, and there are 4-8 pairs of lateral veins. Spike inflorescence, with branching tips attached; Bracts leafy, early setting; Calyx lobes 5, outer layer pubescent; The corolla tube is funnel-shaped and light purple in color. The corolla tube is slightly downward curved near the middle, with a 5-lobed apex; 4 stamens, 2-strong; The ovary is superior, the style is slender and hairy. Capsule.
3. Origin distribution
Born in valleys and damp areas under sparse forests, mostly cultivated. Distributed in Fujian, Guangdong, Sichuan, and various regions south of the Yangtze River Basin.
4. Harvesting and processing
Harvest in summer and autumn, remove aboveground stems, wash and sun dry.
5. Characteristics of medicinal herbs
The rhizome of Nanban Blue Root is round, often curved, and has branches. The surface is grayish brown with fine longitudinal stripes; Enlarged nodes with fine roots or stem residues on them; The outer skin is easy to peel off and appears blue gray. Hard and brittle, easily broken, with an uneven cross-section. The skin is blue gray, and the wood is gray blue to light yellow brown. There is pulp in the center. The roots are of varying thickness, curved and branched, with slender and flexible roots. Slight breath, light taste.
6. Nature, taste, and meridian tropism
Bitter taste, cold nature. Guixin Meridian and Stomach Meridian.
7. Effect and function
Clear heat and detoxify, cool blood and reduce swelling. It belongs to the category of heat clearing and detoxifying drugs under the category of heat clearing drugs.
8. Clinical applications
9-15 grams, decoct and take. It is mainly used to treat viral and bacterial diseases such as hepatitis B, chickenpox, tonsillitis, pharyngitis, etc. in clinical practice.
9. Pharmacological research
South Banlangen decoction has certain antibacterial effects and effects, and has an inhibitory effect on virus proliferation in vitro. It also has antipyretic and anti-inflammatory effects.
10. Chemical composition
The whole plant of Nanbanlangen contains triterpenoids. Indirubin has anticancer activity - (3H) - quinolone has anti-inflammatory and antihypertensive activity, and its roots contain indole glycosides, chrysophanol, and various amino acids. It also contains components such as indigo glycoside, indirubin lupine ketone, lupine alcohol, betulin alcohol, and β - sitosterol.
11. Taboos for use
Patients with spleen and stomach deficiency cold, lack of solid fire and heat toxicity should use with caution.
12. Compatibility prescription
① Treatment for mumps: 30g of Nanban Langen, or 15g of Honeysuckle and Dandelion each, decocted in water; Mash fresh Malay leaves for external use. (Zhejiang Southern Version Reform Edition)
② Treatment of sore throat: 30g of Nanban Langen, 30g of Kaihou Arrow, 30g of Shandougen, and 9g of Mabo. Boiled in water. (Chongqing Herbal Medicine)
③ To prevent pediatric asthma induced pneumonia: use 4.5g of Nanban Langen, Honeysuckle, and Yizhi Huanghua each for the ages of 4-7, and 3g each for those under 3 years old. Boil in water, take 3-4 times a day. (New Edition of Zhejiang Southern Materia Medica)
④ To treat mild heat in summer and persist for a long time: 30g of Nanban Langen, 9g of Chaihu, and 9g of Beisha Shen or Hai'er Shen for those with weak body. Boil in water. Take one dose daily for 7-10 consecutive days. (New Edition of Zhejiang Southern Materia Medica)
⑤ Treatment for heat and toxic sores: 30g of Nanbanlangen, 30g of Yinhuateng, 30g of Dandelion, and 15g of Poria cocos. Stewed meat suit. (Chongqing Herbal Medicine)
The content of the article is for clinical reference only. Non professionals in traditional Chinese medicine are not allowed to try medication.