Botanical Overview
Huang Po (Phellodendron amurense) is a flowering plant in the Rutaceae family. Traditional medicine systems have documented several valuable applications for this species, supported by its observed therapeutic effects. The citrus family (Rutaceae) includes trees and shrubs with gland-dotted leaves that release aromatic oils when crushed. The flowers are typically white with four or five petals, and the fruits are often modified berries with a leathery rind. Most species produce alkaloids and limonoids with medicinal activity.
General Description
It is a major source of huáng bò (Chinese: 黄柏 or 黄檗), one of the 50 fundamental herbs used in traditional Chinese medicine. The Ainu people used its fruit, called “shikerebe-ni” (in Ainu, sikerpe), as a painkiller. It is known as hwangbyeok in Korean and (キハダ) kihada in Japanese. It is native to eastern Asia: northern China, northeast China, Korea, Ussuri, Amur, and Japan, the Amur cork tree is considered invasive in many parts of North America. The State of Massachusetts lists it as a noxious weed.
Family Context
The Rutaceae family is primarily tropical and subtropical. Notable medicinal members include:
- Kabusu — 76 documented uses
- Petitgrain — 76 documented uses
- Rue — 54 documented uses
- Orange — 47 documented uses
Geographic Distribution
Huang Po has been recorded in 10 countries and territories worldwide, including Canada, China, Germany, Estonia, Japan, and others.
Traditional Uses
Huang Po has been traditionally used for digestive health, respiratory conditions, and skin and wound care, among other applications.
Digestive health.
- Stomachic
- Vermifuge
For digestive complaints, the herb is typically prepared as a tea or decoction taken before meals. The bitter compounds stimulate digestive secretions and improve nutrient absorption. Some traditions use the powdered root or leaves in small doses as a stomachic tonic.
Respiratory conditions.
- Expectorant
Respiratory conditions are addressed through steam inhalation of the herb’s vapors or internal use as a warm tea. The hot infusion acts as an expectorant, helping to loosen phlegm and clear congestion. Some traditions combine it with honey for coughs.
Skin and wound care.
- Skin
- Itch
For skin conditions, the fresh or dried plant is applied topically as a poultice, wash, or compress. A strong decoction can be used to clean wounds and sores. The antimicrobial properties help prevent infection while promoting tissue repair.
Active Compounds
Phytochemical research has identified 30 compounds in this species, including a diverse array of phytochemical classes (see the Complete Chemical Inventory below for the full list).
The identified compounds include the following categories:
- Flavonoid: antioxidant compounds that protect cells from oxidative damage
- Terpene: aromatic compounds with anti-inflammatory and antimicrobial properties
- Sterol: cholesterol-like compounds with anti-inflammatory properties