Wu Bei Zi
StarMelaphis chinensis (Bell) Baker (on Rhus chinensis Mill.)
Traditionally used for
- Teeth & mouth
- Cough & breathing
- Bowel health
- Fertility & vitality
- Skin
☯ TCM Properties
Clears Lung Heat and Drains Lung Fire; Astringes the Intestines and Stops Diarrhea; Astringes to Stop Sweating; Secures Essence and Stops Seminal Emission; Stops Bleeding; Absorbs Dampness and Heals Sores
Traditional Chinese Uses
Wu Bei Zi (Chinese gall, sumac gall) is a cold, astringent substance formed by gall insects on sumac trees. It is one of the most powerfully astringent substances in Chinese medicine, used to stop chronic diarrhea, control abnormal sweating, stop bleeding, and consolidate Jing. Topically, it treats weeping skin conditions, mouth ulcers, bleeding gums, and hemorrhoids. Its extreme astringency is deployed in formulas addressing leakage conditions where urgent consolidation is required.
Pharmacological Effects
- Antibacterial: Decoction inhibited in vitro Pseudomonas aeruginosa, Bacillus dysenteriae and other Bacillus spp., E. coli, Staphylococcus aureus, S. albus and Diplococcus pneumoniae.
- Hepatoprotective and antioxidation: Oral gallotannin 75 mg/kg reduced the SGPT rise in mice given NaNO2 plus aminopyrine (0.2 g/kg i.g.); i.p. tannin was ineffective and oral tannin did not protect against CCl4 injury. In vitro gallotannin scavenged NO2- at 5 µg/ml and inhibited ·OH production at 25 µg/ml.
Source: Zhu YP. Chinese Materia Medica: Chemistry, Pharmacology and Applications. Harwood Academic, 1998, p. 659.
Relationships
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Botanical Description
Wu Bei Zi, the Chinese gallnut, is the dried insect-induced gall formed on the leaves and petioles of the Chinese sumac Rhus chinensis Mill. (Anacardiaceae) by the aphid Melaphis chinensis (Hemiptera, Aphididae). The aphid is host-alternating: its sexual generation parasitizes mosses, while the asexual gall-forming generation feeds on Rhus chinensis, where its saliva induces the plant to produce hollow, irregular, often horn- or fist-shaped outgrowths 3–9 cm long, with thin pale-brown velvety walls enclosing the developing aphid colony. The mature galls are collected in autumn before the winged aphids emerge, scalded to kill the insects, and sun-dried. The walls contain very high concentrations of hydrolyzable tannins (up to 70% gallotannin), the basis of the substance’s extreme astringency. In TCM Wu Bei Zi is sour, astringent, and cold, binding the lung, intestine, and lower jiao to stop chronic cough, diarrhea, sweating, bleeding, and seminal emission; it is also applied externally to sores and ulcers.
Active Constituents
Chinese gallotannin (gallotannins)
Hydrolyzable tanninsConcentration: Approximately 50-70% of the gall
The dominant constituents: a glucose core esterified with multiple galloyl units (from tri- up to about 14 galloyl residues). Responsible for the strong astringent, antibacterial, antiviral, and hemostatic actions; higher-galloylation species (e.g., hexa- to hepta-galloylglucose) show the strongest antibacterial and antioxidant activity.
Gallic acid
Phenolic acidConcentration: Up to about 20% (hydrolysis product of gallotannins)
Identified as the main demineralization-inhibiting and antimicrobial small molecule; contributes antioxidant, anti-inflammatory, and anticaries activity.
Methyl gallate
Phenolic esterConcentration: Approximately 7%
A galloyl ester with antibacterial and antioxidant properties, complementing the activity of free gallic acid.
Penta-O-galloyl-beta-D-glucose (PGG)
GallotanninConcentration: Notable component of the tannin fraction
A well-studied gallotannin with antioxidant, antiviral, anti-inflammatory, and antitumor activity in experimental studies.
Ellagic acid
PolyphenolConcentration: Minor constituent
A polyphenol formed alongside gallic acid derivatives, contributing antioxidant and astringent effects.
Higher galloylglucoses (hexa-/hepta-galloylglucose)
GallotanninsConcentration: Fraction of total tannins
High-molecular-weight gallotannins showing the greatest antibacterial activity in the series (e.g., against Bacillus cereus and Salmonella typhimurium), with activity positively correlated with the number of galloyl groups.
⚠ Drug Interactions
Oral iron and mineral supplements
The high tannin content chelates iron, calcium, zinc, and similar cations in the gut lumen, forming insoluble complexes that impair their absorption.
Clinical note: Separate ingestion of Wu Bei Zi from iron or mineral supplements by several hours.
Alkaloid-containing drugs and cationic medications
Tannins precipitate alkaloids and many basic/cationic drug molecules, potentially lowering absorption and therapeutic effect when taken together orally.
Clinical note: Avoid simultaneous oral dosing with alkaloidal drugs; stagger administration times.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3–6 g | Daily | — | — | 中国药典 2020 【用法与用量】3～6g。外用适量。 【性味与归经】酸、涩，寒。归肺、大肠、肾经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Preparation Methods
Powder (oral astringent)
Parts: gall
The dried gall is ground to a fine powder; roughly 1-1.5 g is taken to astringe the intestines, stop chronic diarrhea, control sweating, and secure essence. Small doses are used because of the potent tannin content.
Decoction
Parts: gall
About 3-6 g decocted in water for internal astringent use; because the constituents are very astringent it is used in low dose and often for short courses.
Topical wash or powder
Parts: gall
Powdered gall, or a decoction used as a wash/gargle, is applied externally for sores, ulcers, bleeding, hemorrhoids, and mouth/throat inflammation, taking advantage of its astringent, drying, and antibacterial actions.
Evidence Tier
Limited evidence · 1 studyRecorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.
Systematic review / meta-analysis
0
Randomized controlled trial
0
Other clinical trial
0
Observational / case report
0
In vitro / animal
1
1 verified · 0 unverified
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Chemical composition of Galla chinensis extract and the effect of its main component(s) on the prevention of enamel demineralization in vitro
Galla chinensis extract was chemically characterized (gallic acid comprising about 71% of the major organic components) and tested in pH-cycling and demineralization models. Gallic acid was identified as the main effective, demineralization-inhibiting component, supporting Galla chinensis as a candidate anticaries agent with a mechanism distinct from fluoride.
⚠ Safety & Contraindications
Contraindications
Its use is prohibited in patients with diarrhea or dysentery due to damp-heat.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, p. 386.
Historical Texts
Kai Bao Ben Cao (Materia Medica of the Kaibao Era)
Song dynasty, 973-974Ben Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming dynasty, 1596References
- Ren YM, et al.. Galla Chinensis, a Traditional Chinese Medicine: Comprehensive review of botany, traditional uses, chemical composition, pharmacology and toxicology . Journal of Ethnopharmacology (2021) [DOI]
- Djakpo O, Yao W. Rhus chinensisandGalla Chinensis– folklore to modern evidence: review . Phytotherapy Research (2010) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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