What is Huang Bai(Cortex Phellodendri Herb)

Huáng bǎi (黄柯 or Huang Bai literally "Huang Bai"), huáng bó (黄柏) or huáng bò (Huang Bai) is one of the fifty basic herbs of Chinese medicine.Also known as Cortex Phellodendri, it is the bark of one of two cypress trees:Phellodendron amurense or Phellodendron chinense.

Cultivation

One of the main producing regions for Cortex Phellodendri (Guan Phellodendron, or "Plateau Phellodendron") is Taoshan District in Heilongjiang Province, but other areas in Heilongjiang, Jilin, Liaoning and Inner Mongolia may also be suitable.These provinces are located in the far north-east of China,near Heilongjiang, known in Russian as Аму́р (Amur River), and cork commonly known as Amur cork tree.Cortex Phellodendri (Sichuan Phellodendron, namely "Lowland Phellodendron") production areas include Sichuan, Hubei, Guizhou, Yunnan, Guangxi.

Preparation 

The bark is collected during Qingming (Qing Ming), the fifth solar term (April 4-20).Dry it and cut it into slices.The bark can be used raw or fried with salt. A typical dose is 3-10 grams.Various water and ethanol extraction methods may have different activities, and methods such as "semi-bionic extraction" have been investigated to improve yields.Some pharmacological activities of bark can be analyzed by using monoclonal antibodies,thin layer chromatography,HPLC,potentiometry or acid potassium permanganate chemiluminescence Berberine levels were standardized.The two species of Phellodendrons (P.amurense and chinense) differ quantitatively, suggesting their clinical use as separate resources.Analysis of 31 commercial samples in 1993 found total levels of five alkaloids in P.wilsonii and P. amurense var samples.Sachalinense is 4.1% (mainly berberine), while P. amurense and Ph. chinense contain 1.5%.The content of four harmful trace heavy metals (arsenic, cadmium, mercury, and thallium) in comfrey for export is restricted by the Pharmacopoeia of the People's Republic of China and the Green Trade Standards for Import and Export of Medicinal Plants and Preparations.

Traditional attributes

The bark is classified in TCM as the Five Elements of Humor, Bitter Cold, and affects the Kidney, Bladder, and Large Intestine meridians. It is said to "clear away heat and dampness","reduce fire and detoxify".