Qian Cao
StarRubia cordifolia L.
Synonyms: Galium cordifolium
Traditionally used for
- Nose & throat
- Urinary & fluids
- Menstrual & women's health
Cautions & contraindications
- Pregnancy
- Young children
- Liver conditions
- Kidney conditions
☯ TCM Properties
Cools the Blood and Stops Bleeding; Invigorates Blood and Dispels Stasis; Stops Bleeding Without Retaining Stasis; Promotes Menstruation
Traditional Chinese Uses
Qian Cao (madder root) is a cool, Blood-moving hemostatic herb with the distinctive quality of stopping bleeding while simultaneously clearing old, stagnant Blood. It is used for heat-type bleeding conditions including heavy menstrual bleeding, nosebleeds, and blood in the urine, but its stasis-dispersing action prevents the accumulation of retained clots — an important consideration in managing menstrual disorders. This dual hemostatic-dispersing action makes it the preferred herb for bleeding from Blood Heat complicated by stagnation.
Western Herbalism Properties
Pharmacological Effects
- Hemostatic and hematopoietic: Topical powder stopped femoral artery bleeding in rabbits; charred herb (0.1 g/20 g oral) shortened mouse bleeding time more than crude; decoction mildly shortened bleeding/coagulation time in humans. Rubidate stimulated hematopoiesis and prevented cyclophosphamide leukopenia in mice.
- Antineoplastic: Cyclic hexapeptides active against several transplanted mouse tumors (P388, L1210, B16 melanoma, colon 38, Lewis lung, Ehrlich); optimal RA-VII dose vs P388 4 mg/kg; RA-V effective against MM2 mammary carcinoma.
- Smooth muscle: Decoction spasmolytic on isolated rabbit intestine (vs acetylcholine); aqueous extract stimulated isolated guinea pig uterus and increased uterine contraction in women in labor.
- Other effects: Warm water extract vasodilated frog web vessels; alizarin had rutin-like inhibition of rat skin connective tissue permeability.
Source: Zhu YP. Chinese Materia Medica: Chemistry, Pharmacology and Applications. Harwood Academic, 1998, p. 427.
Relationships
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Botanical Description
Rubia cordifolia (Rubiaceae), Indian madder or Qian Cao, is a perennial herbaceous climbing or scrambling vine with slender, quadrangular, retrorsely prickly stems 1.5-3.5 m long that scramble over neighboring vegetation. Whorls of 4 (occasionally 6-8) cordate to ovate-lanceolate leaves 2-9 cm long with retrorsely prickly margins and petioles surround each node. Small greenish-yellow to white five-lobed flowers are borne in axillary and terminal cymose panicles, followed by paired globose, fleshy, glossy black drupes 4-6 mm across when ripe. The cylindrical, branched root and rhizome have a characteristic deep red bark rich in anthraquinone pigments (alizarin, purpurin) historically used as a textile dye. Native across temperate and tropical Asia, including India, China, and the Himalayan region. (Sources: POWO; Wikipedia; PFAF)
Active Constituents
Rubiadin (1,3-dihydroxy-2-methylanthraquinone)
HydroxyanthraquinoneConcentration: described as a major constituent of the root and as the anthraquinone that primarily originates from this species; no pharmacopoeial limit and no routine assay is applied to it
This is the compound of concern. Rubiadin is a metabolite of lucidin-3-O-primeveroside and is itself carcinogenic: in a rat medium-term multi-organ bioassay, 0.04% dietary rubiadin significantly increased atypical renal tubules and hyperplasias and induced renal cell adenomas and carcinomas, and also increased GST-P-positive liver cell foci and large-intestinal dysplasias. It is confirmed present in Rubia cordifolia, but it has not been routinely quantified in the Chinese Pharmacopoeia drug and there is no upper limit on it.
Alizarin (1,2-dihydroxyanthraquinone)
HydroxyanthraquinoneConcentration: not quantified in the pharmacopoeial drug
Alizarin also increased renal cell tumours in the same rat multi-organ bioassay at 0.04% of the diet, though at a lower incidence than rubiadin. Its glycoside alizarin primeveroside is converted on oral dosing in the rat to 1-hydroxyanthraquinone, which IARC classifies in Group 2B (possibly carcinogenic to humans).
Lucidin and lucidin primeveroside
Hydroxyanthraquinone and its primeverosideConcentration: not quantified in Rubia cordifolia; the measured values in the literature are for Rubia tinctorum
Lucidin is mutagenic in five Salmonella typhimurium strains without activation, mutagenic at the HPRT locus in V79 cells, causes DNA single-strand breaks and DNA-protein cross-links, induces DNA repair synthesis in rat hepatocytes, and forms deoxyguanosine adducts in vivo. Lucidin is attributed to R. cordifolia in phytochemical compilations, but neither of the two dedicated modern reviews of the drug inventories it, and no quantitative determination of lucidin in R. cordifolia root has been published. The measured content, the DNA-adduct work and the carcinogenicity bioassays all used R. tinctorum. This is where the data run out.
Purpurin (1,2,4-trihydroxyanthraquinone)
HydroxyanthraquinoneConcentration: Chinese Pharmacopoeia marker, not less than 0.10% of the dried root and rhizome; measured at 0.00 to 3.03 mg/g across 46 wild sampling sites in seven Chinese provinces, with many Sichuan samples below the standard
One of the two quality-control markers for the drug. It is antioxidant and has been studied for anticancer, antibacterial and neuromodulatory effects, and after oral dosing of R. cordifolia extract (0.82 g/kg) in rats it reached a Cmax of 70.10 ng/mL at 1.61 h. It is a potency marker, not a safety marker.
Mollugin
Naphthohydroquinone (naphthoquinone-type)Concentration: Chinese Pharmacopoeia marker, not less than 0.40% of the dried root and rhizome; measured at 0.03 to 10.09 mg/g across 46 wild sampling sites, with almost all Sichuan sites below the standard
The second pharmacopoeial marker. Neuroprotective, anti-inflammatory, anticancer and antiviral in preclinical work; rat Cmax 52.10 ng/mL at 1.99 h after 0.82 g/kg of the extract orally.
Munjistin
Anthraquinone carboxylic acid (xanthopurpurin-2-carboxylic acid)Concentration: described as one of the two main anthraquinones of the root alongside purpurin; not a pharmacopoeial marker
A major root anthraquinone. Rat Cmax 26.09 ng/mL at 2.58 h after oral dosing of the extract, the slowest-absorbed of the three markers followed pharmacokinetically.
RA-V (deoxybouvardin) and RA-VII
Bicyclic hexapeptides (Rubia RA-series cyclopeptides)Concentration: roughly 100 micrograms per gram of root (about 0.01%) for RA-V and RA-VII; other RA congeners below 1 microgram per gram
The most potent cytotoxins in the drug. They inhibit eukaryotic protein synthesis by binding the ribosome, stabilise F-actin and cause G2 arrest, and inhibit Wnt, Myc and Notch signalling at nanogram-per-millilitre concentrations. RA-VII went into phase I trials as an anticancer drug in Japan. Their presence means Qian Cao is not a pharmacologically inert blood-cooling herb even at the low concentration found.
⚠ Drug Interactions
Other anthraquinone-containing herbs and stimulant laxatives (Da Huang/Rheum, Hu Zhang/Polygonum cuspidatum, senna, aloe)
Rubiadin, confirmed in R. cordifolia, was carcinogenic on its own in rats at 0.04% of the diet, targeting kidney, liver and large intestine, and alizarin was weakly carcinogenic in the same assay. Whole madder root from the sister species R. tinctorum produced dose-dependent benign and malignant liver and kidney tumours in ACI rats over 780 days, with DNA adducts in liver, kidney and colon and an adduct co-migrating with the lucidin-deoxyguanosine adduct. Co-prescribing several hydroxyanthraquinone herbs adds these exposures together. Long-term anthraquinone herb use is also the recognised cause of melanosis coli.
Clinical note: Do not stack Qian Cao with other anthraquinone herbs, and keep courses short and intermittent rather than continuous. Avoid entirely in pregnancy, in children, and in anyone with existing renal or hepatic disease or a personal or family history of renal or colorectal cancer. There is no established safe chronic dose.
Nephrotoxic drugs (aminoglycosides, ciclosporin, tacrolimus, cisplatin, long-term NSAIDs)
The proximal renal tubule is the primary target organ of the anthraquinones in this genus. Rubiadin produced cytoplasmic swelling and karyomegaly in the outer medulla after one week of oral dosing in rats and atypical tubules after 26 weeks, and whole madder colour produced karyomegaly, atypical tubules and renal cell adenomas and carcinomas dose-dependently in a two-year F344 rat study. The extrapolation to human co-medication is not directly measured.
Clinical note: Avoid concurrent use with nephrotoxic drugs. If Qian Cao is used at all in a patient on such therapy, check renal function before and during the course.
Anticoagulants and antiplatelet drugs (warfarin, direct oral anticoagulants, aspirin, clopidogrel)
The drug is used traditionally both to stop bleeding and to invigorate blood, and modern reviews credit it with effects on the coagulation-fibrinolysis system. The raw drug is described as blood-moving and the charred drug (Qian Cao Tan) as astringent and haemostatic, so the direction of effect depends on which preparation is dispensed. No human coagulation study of R. cordifolia has been published, so neither direction can be relied on in a patient on an anticoagulant.
Clinical note: Record which preparation is being used, raw or charred. Monitor INR or clinical bleeding when Qian Cao is added to or withdrawn from an anticoagulated patient's formula.
Rubia schumanniana and Rubia magna sold as Rubiae Radix et Rhizoma (documented adulterants)
Rubia schumanniana E. Pritz. and Rubia magna P. G. Xiao are documented common adulterants of Rubiae Radix et Rhizoma. An LC-MS ion-identity method published in 2025 detected 3% adulteration and identified three market samples as adulterants. Nothing is known about the rubiadin or lucidin content of these substitute species, so the toxicological reasoning above does not transfer to them.
Clinical note: Source Qian Cao from suppliers who assay purpurin and mollugin against the Chinese Pharmacopoeia limits. A sample failing those limits is either poor-quality R. cordifolia or a different species.
Rubia tinctorum (European madder) substituted or confused with Qian Cao
R. tinctorum root is the species in which lucidin was identified as the mutagenic principle, in which DNA adducts and liver and kidney tumours were demonstrated in rats, and whose extract (madder colour) was delisted as a food additive in Japan in 2004 after a two-year rat bioassay showed unequivocal renal and hepatic carcinogenicity. Reviews of R. cordifolia note that the European Commission has treated R. tinctorum as a plant carrying serious risks and that medicinal madder root products are no longer permitted in Germany. Qian Cao and European madder are both red-dye Rubia roots and are visually similar as cut crude drug.
Clinical note: Confirm botanical origin. R. tinctorum is not an acceptable substitute for Qian Cao in any jurisdiction, and a supplier offering madder root as Qian Cao should be rejected.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 6–10 g | Daily | — | — | 中国药典 2020 【用法与用量】6～10g。 【性味与归经】苦，寒。归肝经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
The combination both astringes to stop bleeding and moves blood to dispel stasis, so bleeding is controlled without retaining stasis.
Blood exhaustion with amenorrhea or irregular uterine bleeding; the pair also appears in Gu Chong Tang (Zhang Xichun).
Core pair of a classical formula — Si Wu Zei Gu Yi Lu Ru Wan, Huang Di Nei Jing Su Wen
Evidence Tier
Moderate evidence · 7 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
7
5 verified · 2 unverified
Show 7 studies
- Carcinogenic potential of alizarin and rubiadin, components of madder color, in a rat medium‐term multi‐organ bioassay
- Induction of kidney and liver cancers by the natural food additive madder color in a two-year rat carcinogenicity study
- Carcinogenicity and DNA adduct formation observed in ACI rats after long-term treatment with madder root, Rubia tinctorum L
- The genotoxicity of lucidin, a natural component of Rubia tinctorum L., and lucidinethylether, a component of ethanolic Rubia extracts
- Identification of a mutagenic substance, in Rubia tinctorum L. (madder) root, as lucidin
- Mitodepressive Effect of Rubia cordifolia Extract on the Bone Marrow Cells of Mice
- Simultaneous Determination of Purpurin, Munjistin and Mollugin in Rat Plasma by Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry: Application to a Pharmacokinetic Study after Oral Administration of Rubia cordifolia L. Extract
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
Carcinogenic potential of alizarin and rubiadin, components of madder color, in a rat medium‐term multi‐organ bioassay
Male F344 rats initiated with five carcinogens were fed 0.008% or 0.04% alizarin or rubiadin for 23 weeks. Rubiadin at 0.04% significantly increased atypical renal tubules and hyperplasias and induced renal cell adenomas and carcinomas, and also increased GST-P-positive liver cell foci and large-intestinal dysplasias. Alizarin increased renal cell tumours at lower incidence. This is the study that matters most for Rubia cordifolia, because rubiadin is a confirmed major constituent of this species rather than only of R. tinctorum.
Induction of kidney and liver cancers by the natural food additive madder color in a two-year rat carcinogenicity study
Male and female F344 rats fed 0%, 2.5% or 5.0% madder colour for 104 weeks showed dose-dependent karyomegaly, atypical renal tubules and hyperplasias, renal cell adenomas and carcinomas, and hepatocellular adenomas and carcinomas in both sexes. The authors call the evidence of carcinogenicity against renal tubule cells and hepatocytes unequivocal. The test material was extracted from Rubia tinctorum, not Rubia cordifolia.
Carcinogenicity and DNA adduct formation observed in ACI rats after long-term treatment with madder root, Rubia tinctorum L
ACI rats fed 1% or 10% madder root for 780 days developed dose-dependent benign and malignant liver and kidney tumours. 32P-postlabelling showed increased DNA adducts in liver, kidney and colon after two weeks at 10%, with an HPLC peak co-migrating with the adduct formed in vitro between lucidin and deoxyguanosine-3'-phosphate. The authors concluded that medicinal use of madder root carries a carcinogenic risk. Again, the species is R. tinctorum.
The genotoxicity of lucidin, a natural component of Rubia tinctorum L., and lucidinethylether, a component of ethanolic Rubia extracts
Lucidin was mutagenic in five Salmonella typhimurium strains without S9 and more so with it, mutagenic at the HPRT locus in V79 cells, and induced DNA single-strand breaks, DNA-protein cross-links, DNA repair synthesis in rat hepatocytes and transformation of C3H/M2 mouse fibroblasts. Lucidin ethyl ether, formed when madder root is extracted with boiling ethanol, was also mutagenic. Note that this means an alcohol extraction of a lucidin-containing Rubia generates a second genotoxic species.
Identification of a mutagenic substance, in Rubia tinctorum L. (madder) root, as lucidin
The original identification: all of the mutagenic activity of madder root extract towards Salmonella typhimurium TA100 and TA98 was attributed to lucidin. This is the finding that ultimately removed R. tinctorum from medicinal use in Germany and from the Japanese food-additive list.
Mitodepressive Effect of Rubia cordifolia Extract on the Bone Marrow Cells of Mice
Extract of R. cordifolia depressed the mitotic rate of Swiss male mouse bone marrow cells at almost all concentrations and exposure times tested, with the effect increasing with exposure duration. This is one of the very few toxicity studies performed on R. cordifolia itself rather than on R. tinctorum.
Simultaneous Determination of Purpurin, Munjistin and Mollugin in Rat Plasma by Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry: Application to a Pharmacokinetic Study after Oral Administration of Rubia cordifolia L. Extract
After 0.82 g/kg of R. cordifolia extract orally in rats, Cmax was 70.10 ng/mL for purpurin (Tmax 1.61 h), 26.09 ng/mL for munjistin (Tmax 2.58 h) and 52.10 ng/mL for mollugin (Tmax 1.99 h), all showing slow absorption and metabolism. This is essentially the only pharmacokinetic dataset for the drug, and it covers none of the genotoxic anthraquinones.
⚠ Safety & Contraindications
- Pregnancy
- Young children
- Liver conditions
- Kidney conditions
Side Effects
- Oral decoction caused prolonged nausea and mild elevation of blood pressure.
Source: Zhu YP. Chinese Materia Medica: Chemistry, Pharmacology and Applications. Harwood Academic, 1998, p. 427.
Historical Texts
Huang Di Nei Jing
Warring States to Han dynastyShen Nong Ben Cao Jing
Han dynastyBen Cao Gang Mu
Ming dynastyReferences
- Shan M, Yu S, Yan H, Chen P, Zhang L, Ding A. A Review of the Botany, Phytochemistry, Pharmacology and Toxicology of Rubiae Radix et Rhizoma . Molecules (2016) [DOI]
- Wen M, Chen Q, Chen W, Yang J, Zhou X, Zhang C, Wu A, Lai J. A comprehensive review of Rubia cordifolia L.: Traditional uses, phytochemistry, pharmacological activities, and clinical applications . Frontiers in Pharmacology (2022) [DOI]
- Watroly MN, Sekar M, Fuloria S, Gan SH, Jeyabalan S, Wu YS, Subramaniyan V, Sathasivam KV. Chemistry, Biosynthesis, Physicochemical and Biological Properties of Rubiadin: A Promising Natural Anthraquinone for New Drug Discovery and Development . Drug Design, Development and Therapy (2021) [DOI]
- Wang Y, Liu H, Yu S, Zhang Y, Huang Y, He X, Chen W. Effects of geographical, soil and climatic factors on the two marker secondary metabolites contents in the roots of Rubia cordifolia L. . Frontiers in Plant Science (2024) [DOI]
- Zhang L, Han T, Wang X, Zhang Y, Zhang J, Jing W, Li M, Cheng X. Identification and Adulteration Evaluation of Rubiae Radix Et Rhizoma and Its Common Adulterants Based on LC-MS and Chemometrics . Molecules (2025) [DOI]
- Rao GMM, Rao CV, Pushpangadan P, Shirwaikar A. Hepatoprotective effects of rubiadin, a major constituent of Rubia cordifolia Linn. . Journal of Ethnopharmacology (2006) [DOI]
- Kawasaki Y, Goda Y, Yoshihira K. The Mutagenic Constituents of Rubia tinctorum. . Chemical and Pharmaceutical Bulletin (1992) [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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