Huang Bo
StarPhellodendron chinense Schneid. / Phellodendron amurense Rupr.
Traditionally used for
- Colds & fever
- Bowel health
- Urinary & fluids
- Menstrual & women's health
- Skin
Cautions & contraindications
- Young children
☯ TCM Properties
Clears Heat and dries Dampness; Purges Fire and Resolves Toxicity; Drains Ministerial Fire; Clears Heat and resolves sores
Traditional Chinese Uses
Huang Bo (phellodendron bark) is an intensely bitter, cold herb that targets Damp-Heat in the lower burner. It is a primary herb for vaginal discharge with a yellow or foul odor, urinary burning and pain, and diarrhea from intestinal Damp-Heat. It also clears Fire from Kidney deficiency — the deficiency heat pattern associated with night sweats, afternoon fever, and bone-steaming sensations. Externally, it treats Damp-Heat skin conditions including eczema and sores.
Western Herbalism Properties
Relationships
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Botanical Description
Phellodendron chinense, and the closely related P. amurense, are deciduous trees in the Rutaceae family, native to East Asia, particularly central and northern China, Korea, and the Amur River region. They typically reach 10-25 meters tall, with a broad spreading crown and thick, deeply furrowed, cork-like grey bark; the inner bark is conspicuously bright yellow and intensely bitter. The opposite, pinnately compound leaves bear 5-13 ovate to lanceolate, acuminate leaflets, each 5-10 cm long, with finely serrate margins and an unpleasant odor when crushed. The trees are dioecious; small yellow-green flowers are borne in terminal panicles in early summer, followed on female trees by clusters of black, pea-sized drupes. In TCM, the inner bark (Huang Bo) is harvested from mature trees and used as a bitter, cold herb to clear damp-heat, drain fire, and detoxify.
Active Constituents
Berberine
Protoberberine isoquinoline alkaloidConcentration: not less than 0.60 percent berberine hydrochloride is required of Phellodendri Amurensis Cortex, against not less than 3.0 percent for Phellodendri Chinensis Cortex
Present in both source species but at roughly a fifth of the concentration in the Amur bark. This is the single most practically important difference between the two drugs that this record covers: a prescription written for the Chinese species and filled with the Amur species delivers far less of the alkaloid the pharmacology rests on.
Palmatine
Protoberberine isoquinoline alkaloidConcentration: not less than 0.30 percent palmatine hydrochloride is required of Phellodendri Amurensis Cortex
Palmatine is the second pharmacopoeial assay marker for the Amur species. The Chinese species is instead assayed on phellodendrine, so the two barks are held to different specifications and are not simply interchangeable grades of one drug.
Magnoflorine
Quaternary aporphine alkaloidProportionally much more prominent in the Amur bark, where magnoflorine and jatrorrhizine have been proposed as quality markers. It has also been reported to raise tissue uptake of berberine when the two are present together, which complicates any simple read-across of dose from berberine content alone.
Phellodendrine
Quaternary tetrahydroprotoberberine alkaloidOccurs in both species and is genus-diagnostic, which is why it and not berberine is the identity marker for Phellodendron against the other berberine-bearing crude drugs.
Obaculactone (limonin)
Limonoid (degraded triterpenoid)A bitter limonoid of the bark. The limonoid fraction, together with the alkaloid ratios, is what allows the two Phellodendron barks to be told apart by chromatographic fingerprint.
⚠ Drug Interactions
Phellodendri Chinensis Cortex (Chuan Huang Bai) substituted by Phellodendri Amurensis Cortex (Guan Huang Bai)
This record names two species as one drug, but the Chinese Pharmacopoeia holds them to different assays and different limits: 3.0 percent berberine plus 0.34 percent phellodendrine for the Chinese bark, against 0.60 percent berberine plus 0.30 percent palmatine for the Amur bark. Chemical and biological differentiation studies confirm that berberine content is far higher in Cortex Phellodendri Chinensis, and a head-to-head comparison in TPA-induced ear oedema in mice found the anti-inflammatory effect of the two barks differed. Practitioners meet this as substitution in the market, not as a taxonomic footnote.
Clinical note: Ask your supplier which species you are being sold and expect the answer to be on the certificate of analysis. Where a formula's effect depends on berberine load, specify the Chinese species by name rather than by the shared pinyin.
Ciclosporin, CYP3A4 and CYP2D6 substrates, and P-glycoprotein substrates
The full berberine interaction set applies here as it does to the Huang Bai record for Phellodendron chinense, and is set out in detail there. What is specific to this record is that it is a two-species entry: because the Amur bark carries roughly a fifth of the berberine, the magnitude of a berberine-driven interaction is not the same across the two source plants, and a patient stabilised on one species may not behave the same way on the other.
Clinical note: Do not assume interaction risk scales with the pinyin name. If a transplant or narrow-index patient is on this herb, re-check drug levels after any change of supplier or species, not only after a change of dose.
Neonatal use and drugs raising unconjugated bilirubin
The restriction that Singapore has applied since 1978 is written against Cortex Phellodendri as a drug, not against one botanical source of it, so it covers both species named in this record. The underlying evidence is the berberine bilirubin-displacement work described under the Huang Bai record; the lower berberine content of the Amur bark reduces but does not remove the concern.
Clinical note: Contraindicated in newborns and in jaundiced infants regardless of which Phellodendron species the pharmacy supplies.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3–12 g | Daily | — | — | 中国药典 2020 【用法与用量】3～12g。外用适量。 【性味与归经】苦，寒。归肾、膀胱经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Evidence Tier
Moderate evidence · 4 studiesRecorded 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
1
0 verified · 1 unverified
In vitro / animal
3
0 verified · 3 unverified
Show 3 studies
- Comparison on the anti-inflammatory effect of Cortex Phellodendri Chinensis and Cortex Phellodendri Amurensis in 12-O-tetradecanoyl-phorbol-13-acetate-induced ear edema in mice
- Chemical and Biological Differentiation of Cortex Phellodendri Chinensis and Cortex Phellodendri Amurensis
- Chemical discrimination of cortex Phellodendri amurensis and cortex Phellodendri chinensis by multivariate analysis approach
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
Some DOIs on this page have not been checked against the registries yet; their studies count as unverified until they are.
Clinical Studies
Comparison on the anti-inflammatory effect of Cortex Phellodendri Chinensis and Cortex Phellodendri Amurensis in 12-O-tetradecanoyl-phorbol-13-acetate-induced ear edema in mice
A direct head-to-head comparison of the two barks that this record treats as one drug, in the TPA ear-oedema model. It is the main in vivo evidence that Cortex Phellodendri Chinensis and Cortex Phellodendri Amurensis do not behave identically, and is the pharmacological counterpart to the pharmacopoeia's decision to hold them to separate standards.
Chemical and Biological Differentiation of Cortex Phellodendri Chinensis and Cortex Phellodendri Amurensis
Chemical and biological profiling of the two source barks, confirming that berberine content is markedly higher in the Chinese species and that the two can be separated on their constituent profiles. It provides the analytical basis for treating substitution of one for the other as a dispensing error.
Chemical discrimination of cortex Phellodendri amurensis and cortex Phellodendri chinensis by multivariate analysis approach
A metabolomics-style multivariate approach that separates the two Phellodendron barks on their chemical fingerprints and identifies the constituents responsible for the separation. It is the method a laboratory would use to check which species a batch actually is.
Tolerance of Phellodendron amurense Bark Extract (Nexrutine®) in Patients with Human Prostate Cancer
A tolerance study of a standardised Phellodendron amurense bark extract in 21 men undergoing surgery or radiation for prostate cancer, nine surgical and twelve irradiated. Two transient grade 3 toxicities occurred during the extract-alone phase and no grade 4 toxicity was seen. It is one of very few human studies conducted on the Amur species itself rather than on isolated berberine, and it is a tolerance study, so it says nothing about efficacy.
Historical Texts
Ben Cao Gang Mu
Ming dynastyReferences
- Sun, Yue; Lenon, George Binh; Yang, Angela Wei Hong. Phellodendri Cortex: A Phytochemical, Pharmacological, and Pharmacokinetic Review . Evidence-Based Complementary and Alternative Medicine (2019) [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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