Cao Dou Kou
StarAlpinia katsumadai Hayata
Traditionally used for
- Digestion
☯ TCM Properties
Transforms Dampness and Moves Qi; Warms the Middle Burner; Stops Vomiting; Disperses Cold
Traditional Chinese Uses
Cao Dou Kou (katsumada galangal seed) is a warm, pungent herb used to warm the Stomach, dry Dampness, and move Qi in the middle burner. It addresses cold-type gastric conditions with vomiting, nausea, abdominal fullness, and poor appetite from Dampness obstructing the middle burner. It is specifically suited for cold-Damp patterns in the Stomach where the Damp is not transforming and the patient has clear signs of cold rather than heat.
Western Herbalism Properties
Relationships
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Botanical Description
Alpinia katsumadai, Katsumada's galangal, is a robust rhizomatous perennial herb of the family Zingiberaceae native to moist forest understorey in southern China (especially Hainan and Guangxi) and northern Vietnam. The fragrant, knotted, branching rhizome gives rise to clumped leafy pseudostems 1.5-3 m tall formed by the overlapping leaf sheaths, bearing alternate, oblong-lanceolate leaves 30-65 cm long and 6-10 cm wide, glabrous and bright green. The terminal, erect, conical raceme 20-30 cm long carries showy white flowers about 3 cm long with a distinctive yellow labellum streaked with red-purple, subtended by deciduous coloured bracts. The fruit is a globose, faintly ribbed, yellowish-brown capsule 1.5-3 cm across containing a tightly packed mass of polygonal greyish-brown aromatic seeds with a pungent, slightly bitter, warming, cardamom-like flavour, harvested when the capsules begin to split.
Active Constituents
Cardamonin
Chalcone (flavonoid)Concentration: The dominant flavonoid of the seed on post-silylation GC-MS profiling
The best-studied single compound of the seed. It is broadly anti-inflammatory and antiproliferative in cell and rodent models, acting on NF-kB and mTOR signalling, and is the compound most often invoked to explain the seed's gastroprotective reputation. All of this evidence is preclinical; no human trial of cardamonin has been reported.
Alpinetin
Flavanone (dihydroflavone)Concentration: Co-occurs with cardamonin and the two are routinely assayed together as the seed's flavonoid marker pair
The flavanone counterpart of cardamonin, isolated alongside it since the earliest chemical work on the genus. It shows anti-inflammatory and antioxidant activity in cell and rodent models. Reported human pharmacokinetic data for alpinetin come from rat studies only.
Katsumadain A
Diarylheptanoid bearing an alpha-pyroneConcentration: A minor isolate; obtained in milligram quantities from seed extract during bioassay-guided fractionation
Isolated from the seed as one of two novel diarylheptanoid anti-emetic principles, both active against copper sulfate-induced emesis in young chicks, which is the closest experimental correlate of the drug's traditional use to stop vomiting. Separately it inhibits influenza virus neuraminidase in vitro with an IC50 of about 1.05 micromolar against human H1N1 A/PR/8/34 and 0.9-1.64 micromolar against four swine H1N1 isolates, binding a site distinct from the sialic-acid pocket that oseltamivir occupies. Both findings are preclinical.
Daucene
Sesquiterpene hydrocarbon (volatile oil)Concentration: 274.41 micrograms per gram of seed by headspace SPME GC-MS
Together with alpha-phellandrene it is the principal determinant of the seed's aroma. The volatile fraction of the seed, of which sesquiterpenes make up about 55%, is the part associated with the drug's traditional warming and anti-emetic action.
alpha-Phellandrene
Monoterpene hydrocarbon (volatile oil)Concentration: 161.25 micrograms per gram of seed by headspace SPME GC-MS
A major monoterpene of the seed aroma profile; monoterpenes account for roughly 37% of the headspace volatiles. In rodents the whole volatile oil of A. katsumadai reduced 5-fluorouracil-induced intestinal mucositis, an effect attributed to the oil rather than to any single terpene.
⚠ Drug Interactions
Rou Dou Kou (Myristica fragrans, nutmeg) substituted for Cao Dou Kou
Cao Dou Kou is one of four Chinese drugs sold under cardamom-type names that are grouped together in the trade and are documented as difficult to authenticate: Bai Dou Kou (Amomum kravanh fruit), Hong Dou Kou (Alpinia galanga fruit), Cao Dou Kou (Alpinia katsumadai seed) and Rou Dou Kou (Myristica fragrans seed). A 2026 comparative review of the four drugs names species authentication as one of the key unresolved problems for the group. The substitution matters clinically because nutmeg contains myristicin and elemicin and causes anticholinergic delirium, tachycardia and hallucinations in overdose, whereas the Alpinia seed has no comparable acute toxicity.
Clinical note: Insist on the botanical binomial, not the pinyin, on the certificate of analysis. GC, HPLC and TLC all separate the four drugs. If a patient reports agitation, flushing, dry mouth or hallucinations after a prescription containing Cao Dou Kou, consider nutmeg substitution and stop the formula.
Bai Dou Kou (Amomum kravanh fruit) or Cao Guo (Lanxangia tsao-ko fruit) substituted for Cao Dou Kou
These are separate pharmacopoeial drugs with distinct chemistry: Cao Dou Kou is defined by cardamonin, alpinetin and the katsumadains; Bai Dou Kou by a fruit oil rich in 1,8-cineole; Cao Guo by a fruit oil in which 1,8-cineole and geraniol dominate, plus bicyclic nonanes such as tsaokoin and isotsaokoin that are characteristic of that species. They are nonetheless routinely confused, because all three sit in the same pinyin family and the same traditional category and the older bencao literature used the bare name dou kou for what is now Cao Dou Kou. Alpinia katsumadai is in fact a documented adulterant of Cao Guo, and in a rat functional dyspepsia model it regulated the fewest metabolic pathways of the four materials tested.
Clinical note: Cao Dou Kou is a seed, Bai Dou Kou and Cao Guo are whole fruits, so gross inspection catches many substitutions. Confirm the binomial and the plant part before dispensing.
Fluorouracil and other mucositis-causing cytotoxic chemotherapy
A. katsumadai volatile oil reduced 5-fluorouracil-induced intestinal mucositis in mice, acting through gut microbiota changes and modulation of glucocorticoid-receptor and mPGES-1/PGE2/EP4 signalling (Liu et al. 2023, animal). There is no human evidence, no data on whether the oil alters fluorouracil exposure, and no oncology guideline supports this use.
Clinical note: Do not present this as an established supportive-care option. Any use alongside chemotherapy should be disclosed to the treating oncologist, since interactions with cytotoxic regimens are untested.
Oseltamivir and other neuraminidase inhibitors
Katsumadain A from the seed inhibits influenza neuraminidase in vitro at low micromolar concentrations and appears to bind outside the sialic-acid pocket targeted by oseltamivir (Grienke et al. 2010, in vitro). This has been discussed as a possible complementary mechanism, but no combination has been studied in animals or humans, and plasma concentrations from an oral decoction are unknown.
Clinical note: Cao Dou Kou is not a substitute for antiviral treatment in influenza. There is no reason to withhold it from a patient taking oseltamivir, and no reason to add it for that purpose.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3–6 g | Daily | — | — | 中国药典 2020 【用法与用量】3～6g。 【性味与归经】辛，温。归脾、胃经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Evidence Tier
Moderate evidence · 6 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
0
In vitro / animal
6
2 verified · 4 unverified
Show 6 studies
- Two Novel Anti-emetic Principles of Alpinia katsumadai
- Antiviral Potential and Molecular Insight into Neuraminidase Inhibiting Diarylheptanoids from Alpinia katsumadai
- Comprehensive metabolites characterization of Alpinia katsumadai seeds via a multiplex approach of UHPLC-MS/MS and GC-MS techniques
- Alpinia katsumadai Hayata Volatile Oil Is Effective in Treating 5-Fluorouracil-Induced Mucositis by Regulating Gut Microbiota and Modulating the GC/GR Pathway and the mPGES-1/PGE2/EP4 Pathways
- Alpinia katsumadai Hayata induces growth inhibition and autophagy-related apoptosis by regulating the AMPK and Akt/mTOR/p70S6K signaling pathways in cancer cells
- Anti-Periodontitis Effect of Ethanol Extracts of Alpinia Katsumadai Seeds
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
Two Novel Anti-emetic Principles of Alpinia katsumadai
Two new diarylheptanoids, katsumadain A and katsumadain B, were isolated from A. katsumadai seed and both suppressed copper sulfate-induced emesis in young chicks. This is the primary experimental support for the drug's classical indication of stopping vomiting, and it identifies specific compounds rather than crediting the crude volatile oil. An animal model in a non-mammalian species; there is no human anti-emetic trial of this seed.
Antiviral Potential and Molecular Insight into Neuraminidase Inhibiting Diarylheptanoids from Alpinia katsumadai
Bioassay-guided work on A. katsumadai seed extract isolated six constituents, of which four diarylheptanoids inhibited influenza neuraminidase at low micromolar concentrations against human H1N1 A/PR/8/34. Katsumadain A was the most active (IC50 about 1.05 micromolar) and also inhibited neuraminidase from four swine H1N1 viruses, with antiviral activity confirmed by plaque reduction. Molecular dynamics work supported binding to a site distinct from the classical sialic-acid pocket.
Comprehensive metabolites characterization of Alpinia katsumadai seeds via a multiplex approach of UHPLC-MS/MS and GC-MS techniques
A three-platform metabolomic map of the seed annotating 82 secondary metabolites. Headspace GC-MS found 30 aroma compounds dominated by sesquiterpenes (55.1%) and monoterpenes (36.8%), with daucene at 274.41 and alpha-phellandrene at 161.25 micrograms per gram; post-silylation GC-MS identified sucrose as the major sugar (23.81 mg/g) and cardamonin as the major flavonoid. Two catechin-guibourtinidol derivatives and a deoxy phloretin C-hexoside are reported for the first time in the genus. This is an analytical characterisation, not a pharmacological study.
Alpinia katsumadai Hayata Volatile Oil Is Effective in Treating 5-Fluorouracil-Induced Mucositis by Regulating Gut Microbiota and Modulating the GC/GR Pathway and the mPGES-1/PGE2/EP4 Pathways
The seed's volatile oil reduced 5-fluorouracil-induced intestinal mucositis in mice, with restoration of gut microbial composition and suppression of the mPGES-1/PGE2/EP4 inflammatory axis alongside glucocorticoid-receptor pathway effects. It is a rodent model of a chemotherapy complication; no human data exist.
Alpinia katsumadai Hayata induces growth inhibition and autophagy-related apoptosis by regulating the AMPK and Akt/mTOR/p70S6K signaling pathways in cancer cells
Extract of A. katsumadai inhibited proliferation of cancer cell lines and induced autophagy-related apoptosis through AMPK activation and Akt/mTOR/p70S6K suppression. A cell-based mechanistic study only; it does not support any clinical anticancer claim for the drug.
Anti-Periodontitis Effect of Ethanol Extracts of Alpinia Katsumadai Seeds
Ethanol extract of the seed suppressed inflammatory mediators and osteoclast-related signalling in cell models of periodontal inflammation. Preclinical; no clinical periodontitis trial of the seed has been reported.
⚠ Safety & Contraindications
Contraindications
Its use is cautious in patients with yin deficiency and blood dryness.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, pp. 131–133.
Historical Texts
Ming Yi Bie Lu (Miscellaneous Records of Famous Physicians)
Attributed to Tao Hongjing, c. 500 CEKai Bao Ben Cao (Materia Medica of the Kaibao Era)
Northern Song, 973-974 CEBen Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming dynasty, 1596Pharmacopoeia of the People's Republic of China, Alpiniae Katsumadai Semen (Cao Dou Kou) monograph
Modern standard, 2020 editionReferences
- El-Haddad AE; Khaled L; Farag MA. Alpinia katsumadai seed from a condiment to ethnomedicine to nutraceutical, a comprehensive review of its chemistry and health benefits . Journal of Traditional and Complementary Medicine (2026) [DOI]
- Yang X; Xie J; Zhang Q; Su S; Wang T; Gao H; Zhao L; Renzhen W; Su J; Zhang Y. Fructus Amomi Rotundus, Fructus Galangae, Semen Alpiniae Katsumadai and Semen Myristicae comparison of traditional medicinal uses, phytoconstituents, bioactivities . Journal of Ethnopharmacology (2026) [DOI]
- Liu L; Chen X; Hu Z. Separation and determination of alpinetin and cardamonin in Alpinia katsumadai Hayata by flow injection–micellar electrokinetic chromatography . Talanta (2007) [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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