Chun Gen Pi 椿根皮 — Chinese Herbal Medicine

Chun Gen Pi (椿根皮) At a Glance

• Herb: Chun Gen Pi
• Chinese name: 椿根皮 (Chun Gen Pi)
• Latin name: Cortex Ailanthi
• Nature: Cold
• Taste: Bitter, Astringent
• Meridian: Liver
• Category: To stop diarrhea by closing the large intestine

The name 椿根皮 (Chūn Gēn Pí) means “root bark of the ailanthus tree,” derived from Ailanthus altissima (Tree of Heaven), a deciduous tree widespread across northern and central China. Bitter and astringent in flavor, cold in nature, it combines strong heat-clearing power with binding astringency — a pairing that suits patterns where damp-heat has lodged in the large intestine or lower jiao and refuses to resolve. Its primary clinical role is checking stubborn or chronic dysentery, profuse leukorrhea, and lower-body bleeding arising from damp-heat or heat damaging the vessels.

Actions & Therapeutic Effects

• Clears heat and dries dampness — disperses damp-heat accumulating in the large intestine and lower jiao
• Astringes the intestines and stops diarrhea — checks chronic or dysenteric loose stool through its bitter binding quality
• Stops bleeding — controls uterine hemorrhage, hematochezia, and hemorrhoidal bleeding
• Eliminates dampness and arrests leukorrhea — treats profuse yellow or foul-smelling vaginal discharge
• Kills intestinal parasites — effective against roundworm and trichomonad infestations
• Clears residual heat from the blood level — useful when heat has not fully resolved in chronic inflammatory conditions

Clinical Applications in TCM

• Damp-heat dysentery with tenesmus and blood in stool — combine with Huang Lian (黄连) and Mu Xiang (木香)
• Chronic slippery diarrhea with concurrent heat signs — pair with Bu Gu Zhi (补骨脂) and Rou Dou Kou (肉豆蔻)
• Uterine hemorrhage (崩漏) with heat in the blood — use with Di Yu (地榆) and Ce Bai Ye (侧柏叶)
• Profuse yellow leukorrhea from damp-heat in the lower jiao — combine with Huang Bai (黄柏) and Bai Guo (白果)
• Hemorrhoidal or rectal bleeding — decoct alone or with Di Yu (地榆) as a wash or oral preparation
• Intestinal roundworm infestation — combine with Ku Lian Pi (苦楝皮) and Bing Lang (槟榔)

Precautions & Safety

• Dosage: 6–12 g in decoction; up to 15 g in severe cases; powdered form 1.5–3 g taken with warm water
• Contraindicated in cold-type diarrhea or dysentery without damp-heat; avoid with Spleen-Stomach deficiency cold presenting as loose stools without burning or urgency
• Use with caution during pregnancy; prolonged use may impair digestive function — monitor Spleen qi

Classical TCM Formulas

• Chun Pi San (椿皮散): Chun Gen Pi, Huang Bai, Bai Tou Weng, Huang Qin — chronic Damp-Heat dysentery. Source: Classical simple formula.
• Gu Jing Wan (固经丸): Gui Ban, Bai Shao, Huang Qin, Huang Bai, Chun Gen Pi, Xiang Fu — Yin deficiency with Heat causing uterine bleeding. Source: Yi Xue Ru Men.
• Bai Tou Weng Tang (白头翁汤) + Chun Gen Pi: Bai Tou Weng, Huang Lian, Huang Bai, Qin Pi + Chun Gen Pi — enhanced astringent action for chronic dysentery.

Herb Combinations

• Chun Gen Pi (椿根皮) + Huang Bai (黄柏) + Bai Tou Weng (白头翁): clears Damp-Heat, astringes, and stops dysentery for chronic amoebic/bacillary dysentery. Source: Classical dysentery formulas.
• Chun Gen Pi (椿根皮) + Gui Ban (龟板) + Bai Shao (白芍): astringes and stops uterine bleeding with Yin deficiency and Heat.
• Chun Gen Pi (椿根皮) + Chun Gen Bai Pi (椿根白皮): the inner root bark is stronger and more commonly used than the trunk bark; often used interchangeably.
• Chun Gen Pi (椿根皮) + Huang Qin (黄芩) + Di Yu (地榆): clears Heat-toxin and stops bleeding for dysentery with blood.

Pharmacology & Research

Quassinoids: deliver ailanthone and related bitter principles; exert antiprotozoal and broad antimicrobial activity.
Tannins: provide dense astringency; bind intestinal mucosa to reduce hypermotility and arrest diarrhea.
Alkaloids: contribute hemostatic and anti-inflammatory effects relevant to hemorrhagic and dysenteric presentations.
Flavonoids: offer antioxidant support; modulate local inflammatory response in damp-heat patterns of the lower jiao.

Classical Descriptions

• “椿根皮治赤白久痢、痔漏下血、崩中帶下，主燥濕清熱。” — Běncǎo Gāngmù (本草纲目), Li Shizhen, 1578