Hong Da Ji
StarKnoxia valerianoides Thorel ex Pit.
Synonyms: Knoxia corymbosa auct. non Willd.
Also known as: Hung Ta Chi · Wade–Giles
Safety at a glance
- High risk · Pregnancy: avoid — toxic purgative
- High risk · Do not combine with Gan Cao (十八反)
- Caution · Graded slightly toxic in our catalogue
- Caution · 5 recorded drug interactions, 4 major or contraindicated
- Note · Contraindications or side effects are listed
No rule in our tables for this herb: breastfeeding, herb–drug, dose ceiling. This is not a safety clearance.
Traditionally used for
- Cough & breathing
- Digestion
- Bowel health
- Urinary & fluids
- Skin
Cautions & contraindications
- Pregnancy
- Breastfeeding
- Kidney conditions
- Toxic — professional use only
☯ TCM Properties
Drains water downward and drives out thin mucus; Reduces swelling and dissipates nodules
Traditional Chinese Uses
Hong Da Ji is the root of Knoxia valerianoides (Rubiaceae), a harsh downward-draining medicinal distinct from the Euphorbia-derived Jing Da Ji. Bitter, pungent and cold (and toxic), it drives pathogenic water and thin mucus (phlegm-fluid) downward through the stool and urine, and reduces swelling and dissipates nodules. Classically it is reserved for severe fluid accumulation patterns: pleural and abdominal water retention, generalized edema, and constipation with fullness in robust patients; it also treats scrofula, phlegm nodules, and toxic sores (often applied topically).
Because it is toxic and forcefully cathartic, dosing is small (roughly 1.5-3 g) and it is used only briefly in strong constitutions. It is contraindicated in pregnancy and in Qi, Blood, Yin or Yang deficiency, and classically antagonizes Gan Cao (licorice). Modern practice favors safer diuretics for most edema.
Western Herbalism Properties
Used In Formulas (3)
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Botanical Description
Knoxia valerianoides (Rubiaceae) is the source of Hong Da Ji, Radix Knoxiae. It is an erect perennial herb 30-70 cm tall arising from a cluster of fleshy, spindle- to tooth-shaped roots that are reddish-brown externally and red-brown in cross-section. Stems are quadrangular and pubescent, bearing opposite, lanceolate to narrowly elliptic leaves 5-10 cm long with entire margins and interpetiolar stipules. Small purple to violet flowers are crowded in dense terminal cymose heads that elongate in fruit, followed by tiny didymous capsules. The curved, tooth-like root, dug in autumn, is the drug: markedly toxic, it drains water downward, reduces swelling and dissipates nodules, and is usually processed with vinegar to temper its harshness.
Grassy hillsides, sunny slopes and open thickets in subtropical to tropical southern China.
Active Constituents
Knoxiadin
AnthraquinoneConcentration: one of the characteristic anthraquinones of the root; not routinely quantified in commercial material
A marker anthraquinone of this species and one of the compounds usually named as an active principle of the root. In a systematic screen of 22 constituents at 10 µM it was inactive against five human cancer cell lines, against PC12 cell damage, against LPS-induced nitric oxide, against microsomal lipid peroxidation, against HIV-1 replication and against PTP1B, so claims of potency should be treated with caution.
Rubiadin
AnthraquinoneConcentration: a consistently reported root anthraquinone
A widespread Rubiaceae anthraquinone. It is also a component of madder colour, and in a rat medium-term multi-organ bioassay rubiadin and alizarin showed carcinogenic potential, which is a relevant caution for a root whose anthraquinone profile overlaps that of madder.
Lucidin
AnthraquinoneConcentration: isolated from the root by more than one independent group
The most safety-relevant constituent identified in this root. Lucidin is mutagenic in bacteria, genotoxic in cultured mammalian cells and forms DNA adducts in mice; it is the compound that led to the withdrawal of madder root (Rubia tinctorum) as a food colour and herbal material in Europe. Its presence in Knoxia valerianoides has been reported repeatedly but has never been quantified in the medicinal drug, and no genotoxicity study has been done on Hong Da Ji itself.
Lucidin omega-methyl ether
AnthraquinoneConcentration: isolated from the ethyl acetate and n-butanol fractions of the root
Inhibited advanced glycation end-product formation in vitro with an IC50 of 62.79 µM, against aminoguanidine at 962 µM as positive control.
Nordamnacanthal
AnthraquinoneConcentration: a characteristic root anthraquinone
One of the anthraquinones repeatedly isolated from the root. It was inactive in the broad cytotoxicity, neuroprotection, anti-inflammatory, antioxidant, anti-HIV and PTP1B screen applied to the 22 constituents of the ethanol extract.
Damnacanthol
AnthraquinoneConcentration: a characteristic root anthraquinone
Isolated from both the ethyl acetate and n-butanol fractions of the root. Reported without notable activity in the AGE and aldose reductase screen relative to its co-isolates.
3-Hydroxymorindone
AnthraquinoneConcentration: reported among the principal root anthraquinones
One of the anthraquinones commonly named as a key component of the root in the Chinese literature.
1,3,6-Trihydroxy-2-methoxymethylanthraquinone
AnthraquinoneConcentration: isolated from the root
The most active compound in the advanced glycation screen of this root, inhibiting AGE formation with an IC50 of 52.72 µM and rat lens aldose reductase with an IC50 of 3.04 µM. These are in vitro findings on isolated compounds and say nothing about the whole drug at clinical doses.
Valeriaquinone A
Anthraquinone-coumarin hybridConcentration: a trace constituent isolated from the root
A structurally unusual hybrid isolated from this species and reported as a selective inhibitor of protein tyrosine phosphatase 1B. Of chemical interest; no bearing on the traditional use.
⚠ Drug Interactions
Euphorbia pekinensis (Jing Da Ji) dispensed as Da Ji
Hong Da Ji is the root of Knoxia valerianoides, a Rubiaceae drug whose chemistry is anthraquinone-based. Jing Da Ji is the root of Euphorbia pekinensis, a Euphorbiaceae drug whose chemistry is casbane diterpenoid-based. Both have been sold and prescribed as Da Ji, both are Pharmacopoeia-graded toxic, and classical texts routinely use the single name for both. They were only separated into distinct monographs from the 1995 edition of the Chinese Pharmacopoeia. Jing Da Ji is the more toxic and more strongly water-draining of the two and must be vinegar-processed; Hong Da Ji is regarded as less toxic and stronger at dispersing swelling and nodules, and does not carry the same mandatory processing requirement. The Latin name attached to this record in the source database, Radix Euphorbiae Pekinensis, is itself an instance of the conflation. Substituting one for the other silently changes the potency, the toxic mechanism and the processing the prescription assumed.
Clinical note: Order by binomial. Verify on receipt: Hong Da Ji roots are short and curved, red-brown outside and red-brown in section; Jing Da Ji roots are longer and conical, grey-brown outside and whitish-yellow in section. Colour of the cut surface is the quickest discriminator. Reject material labelled only Da Ji.
Gan Cao (Glycyrrhiza uralensis, Glycyrrhiza glabra) and licorice-containing formulas
Hong Da Ji inherits the Eighteen Incompatibilities prohibition against Gan Cao because it is dispensed under the name Da Ji, and every practical materia medica applies the prohibition to it. The honest position is that the modern experimental work on the Da Ji and Gan Cao incompatibility, covering renal cell toxicity, CYP2C9 induction and gut microbiota disruption, has been done on Euphorbia pekinensis, not on Knoxia valerianoides. No study has tested Knoxia valerianoides with Glycyrrhiza. Because the two drugs are chemically unrelated, the mechanism established for the Euphorbia cannot simply be assumed to transfer. The prohibition should still be observed, but it rests on classical authority and on the shared name rather than on evidence about this species.
Clinical note: Do not combine with Gan Cao. Check patent formulas and granule blends for hidden licorice. Do not tell a patient the prohibition has been experimentally demonstrated for this particular root, because it has not.
Digoxin and other cardiac glycosides; loop and thiazide diuretics
Hong Da Ji is used to drive off accumulated fluid in ascites and pleural effusion by catharsis and diuresis, and it is prescribed to exactly the patient group most likely to be on digoxin and loop diuretics. Potassium depletion from any source increases digoxin binding at Na,K-ATPase and lowers the arrhythmia threshold. No study has examined this combination with this herb, so the mechanism is inferred from the drug's action rather than demonstrated.
Clinical note: Do not use in a digitalised patient or alongside pharmaceutical diuretics without electrolyte and renal monitoring. Stop at the first sign of excessive fluid loss rather than completing a fixed course.
Concurrent oral medication of any kind
Any drug that produces watery stools shortens intestinal transit and can carry co-administered oral medication through before it is absorbed. This is a generic consequence of catharsis rather than a documented property of this species.
Clinical note: Separate essential oral medication from the herb, and be alert to loss of effect of narrow-therapeutic-index drugs such as levothyroxine, antiepileptics and oral contraceptives during a course.
Pregnancy (all trimesters)
The drug is contraindicated in pregnancy throughout the classical and modern Chinese literature as a toxic drastic water-expelling agent. It also contains lucidin, an anthraquinone that is mutagenic in bacteria, genotoxic in mammalian cells and DNA-adduct-forming in mice, which is a further reason to avoid exposure in pregnancy even though the content in the drug has never been measured.
Clinical note: Do not prescribe in pregnancy, when pregnancy is possible, or during breastfeeding. Given the lucidin question, avoid long or repeated courses in anyone.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 1.5–3 g | — | — | — | ChP 2025. 红大戟。内服醋制用 — vinegar-processed for internal use; in pills or powder 1 g per dose. Corrected from a generic 6-15g decoction filler value generated from tcm_category. |
| topical | Appropriate amount | — | — | — | ChP 2025. 外用适量，生用。 |
Dosage Calculator
⚖ Dosage Calculator
A weight-based mathematical estimate for Hong Da Ji. Not a prescription.
Evidence Tier
2 studies on recordRecorded 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
2
1 verified · 1 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
Anthraquinones from the Roots of Knoxia valerianoides
Twenty-two constituents were isolated from an ethanol extract of the root, including nordamnacanthal, ibericin, rubiadin, damnacanthol, 3-hydroxymorindone, knoxiadin, lucidin, xanthopurpurin, digiferruginol and rubiadin-1-methyl ether, thirteen of them for the first time from this species. Notably, at 10 µM none of them was active against the HCT-8, Bel7402, BGC-823, A549 or A2780 cancer cell lines, against deserum and glutamate-induced PC12 cell damage, against LPS-induced nitric oxide production, against rat liver microsomal lipid peroxidation, against HIV-1 replication or against PTP1B. A useful negative result against the broad activity claims made for this root.
Anthraquinones from the Roots of Knoxia valerianoides inhibit the formation of advanced glycation end products and rat lens aldose reductase in vitro
Eight compounds were isolated from ethyl acetate and n-butanol fractions of the root: lucidin, lucidin omega-methyl ether, rubiadin, damnacanthol, 1,3,6-trihydroxy-2-methoxymethylanthraquinone, 3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone, its 3-O-beta-primeveroside, and vanillic acid. 1,3,6-Trihydroxy-2-methoxymethylanthraquinone inhibited advanced glycation end-product formation most strongly (IC50 52.72 µM, against aminoguanidine at 962 µM), and rat lens aldose reductase was inhibited by four of the compounds with IC50 values of 2.05 to 6.39 µM. Isolated-compound in vitro work only; it does not support any diabetic indication for the crude drug.
⚠ Safety & Contraindications
- Pregnancy
- Breastfeeding
- Kidney conditions
- Toxic — professional use only
Contraindications
Contraindicated in pregnancy and in the weak or depleted.
Safety Warnings
- A purgative for short-term use only.
- Incompatible with Gan Cao under the classical eighteen incompatibilities.
- Distinct from Jing Da Ji (Euphorbia pekinensis) despite the shared Da Ji name — the two are different plants with different toxicities.
⚠ Rule-Based Cautions
These entries come from the deterministic rule tables that gate Verscienta's formula tools — classical pair prohibitions, pregnancy and lactation contraindications, dose ceilings, and drugs outside the Chinese Pharmacopoeia. The botanical-genus entries are different: advisory notes are not part of the safety screen; the Aristolochia genus check is.
Incompatibilities (十八反 / 十九畏)
- 十八反: Gan Cao × Da Ji — avoid combining with Gan Cao / Glycyrrhiza / Licorice
Pregnancy
Avoid toxic purgative
⚠ Toxicity Information
Purgation with abdominal pain, nausea and vomiting; dehydration on repeated dosing.
Historical Texts
Pharmacopoeia of the People's Republic of China
modern, 1995 edition onwardReferences
- Zhao F, Wang S, Lin S, Zhu C, Yue Z, Yu Y, Liu B, Wu X, Yang Y, Li Y, Shi J. Natural and unnatural anthraquinones isolated from the ethanol extract of the roots of Knoxia valerianoides . Acta Pharmaceutica Sinica B (2012) [DOI]
- Zhou Z, Jiang S, Zhu D, Lin L. Anthraquinones from Knoxia valerianoides . Phytochemistry (1994) [DOI]
- Jiang Y, Yang R, Qu Z, Hou G, Cong W, Wang C, Zhao F. Valeriaquinone A, a unique anthraquinone-coumarin hybrid with selective inhibition of PTP1B from Knoxia valerianoides . Chinese Chemical Letters (2022) [DOI]
- Westendorf J, Poginsky B, Marquardt H, Groth G, Marquardt H. The genotoxicity of lucidin, a natural component of Rubia tinctorum L., and lucidinethylether, a component of ethanolic Rubia extracts . Cell Biology and Toxicology (1988) [DOI]
- Inoue K, Yoshida M, Takahashi M, Fujimoto H, Shibutani M, Hirose M, Nishikawa A. Carcinogenic potential of alizarin and rubiadin, components of madder color, in a rat medium-term multi-organ bioassay . Cancer Science (2009) [DOI]
- Zhao F, Zhao S, Han J, Wang Y, Wang Y, Wang C. Antiviral anthraquinones from the roots of Knoxia valerianoides . Phytochemistry Letters (2015) [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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