Kuan Dong Hua
StarTussilago farfara L.
Traditionally used for
- Cough & breathing
Cautions & contraindications
- Pregnancy
- Breastfeeding
- Liver conditions
☯ TCM Properties
Moistens the Lungs and Descends Qi; Stops Cough; Resolves Phlegm
Traditional Chinese Uses
Kuan Dong Hua (coltsfoot flower bud) is a warm, gentle herb best known for its reliable action in calming and stopping cough. It redirects Lung Qi downward, dissolves Phlegm, and moistens the Lungs without being overly drying or harsh — making it appropriate for coughs of many varieties, both acute and chronic. It is most commonly paired with Zi Wan (aster root) to enhance the combined phlegm-clearing and cough-stopping effect.
Western Herbalism Properties
Traditional Uses
The Iroquois prepared a compound infusion of the roots that was taken as a cough medicine and as a remedy for consumption (tuberculosis) (Herrick, 1977).
Relationships
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Botanical Description
Tussilago farfara is a low-growing herbaceous perennial in the Asteraceae, native across Europe, North Africa and temperate Asia and widely naturalised in North America, where it colonises disturbed ground, roadside banks, stream sides, gravelly slopes and clay soils. Plants spread by long, scaly, white underground rhizomes that produce two distinct kinds of shoots. In late winter and early spring, before any foliage appears, scaly, reddish flowering stems 10-20 cm tall arise singly, each topped by a solitary, bright yellow capitulum 1.5-3 cm across, with many narrow ray florets surrounding a disc; these are followed by spherical, dandelion-like seed heads of plumed achenes. Only after flowering do the large basal leaves expand: long-petiolate, broadly cordate to polygonal, 10-20 cm wide, with shallowly toothed margins, dark green above and densely white-felted with cottony hairs beneath.
Active Constituents
Senkirkine
Otonecine-type 1,2-unsaturated pyrrolizidine alkaloidConcentration: The most abundant pyrrolizidine alkaloid of the drug. In a UPLC-MS/MS survey of 386 herbs of the 2020 Chinese Pharmacopoeia, the Tussilago farfara sample carried 17,600.2 micrograms per kilogram of total pyrrolizidine alkaloids, ten alkaloids in all, senkirkine leading. Wild Polish leaf material by contrast averaged 0.19 plus or minus 0.11 micrograms per gram dry matter, so material varies by orders of magnitude
Hepatotoxic, genotoxic and tumorigenic. The C1-C2 double bond is the toxic feature: hepatic CYP2A6, CYP3A4 and CYP3A5 oxidise it to reactive pyrrolic esters that alkylate protein and DNA and destroy liver sinusoidal endothelial cells, giving hepatic sinusoidal obstruction syndrome with ascites, effusion, oedema, and in severe cases liver failure, transplantation or death. Injury can progress after the herb is stopped. Blood pyrrole-protein adducts are the diagnostic biomarker.
Senecionine N-oxide
Pyrrolizidine alkaloid N-oxideConcentration: Second most abundant pyrrolizidine alkaloid in the pharmacopoeial Tussilago farfara sample
Not detoxified by being an N-oxide. N-oxides are reduced back to the parent 1,2-unsaturated alkaloid in the gut and liver, so they carry the full toxic burden of the free base. Any assay that measures only free alkaloids and ignores N-oxides understates the exposure.
Senecionine
Retronecine-type 1,2-unsaturated pyrrolizidine alkaloidConcentration: Third most abundant pyrrolizidine alkaloid in the pharmacopoeial sample; mean 0.23 plus or minus 0.18 micrograms per gram dry matter across 20 wild Polish leaf samples, where the total alkaloid mean was 0.42 plus or minus 0.26 micrograms per gram
The archetypal hepatotoxic pyrrolizidine alkaloid, bioactivated by the same CYP-dependent route as senkirkine and responsible for sinusoidal obstruction syndrome in outbreaks attributed to other plants of the tribe. Its presence here is what places this drug in the same toxicological class as comfrey and Gynura japonica.
Tussilagone
Sesquiterpene esterConcentration: Principal sesquiterpene of the flower bud; in rats given Farfarae Flos extract at 3.90 and 7.80 g per kg it reached peak plasma concentration within about 0.2 to 0.7 hours and had the shortest terminal half-life of the constituents measured, with lower Cmax and AUC than the phenolic acids
The main non-alkaloid active. It suppressed RANKL-driven osteoclast differentiation and bone resorption without cytotoxicity, working through mitochondrial reactive oxygen species and Nrf2 stabilisation, and reduced bone loss in ovariectomised and lipopolysaccharide-treated mice. Anti-inflammatory in cell and animal models. All preclinical.
Chlorogenic acid
Caffeoylquinic acidConcentration: One of seven phenolic acids quantified in rat plasma after Farfarae Flos extract, alongside neochlorogenic acid, cryptochlorogenic acid, caffeic acid and isochlorogenic acids A, B and C; the phenolic acids as a group had the highest Cmax and AUC of the constituents measured
The best-absorbed constituent class of the drug in rodents. Antioxidant and anti-inflammatory in the usual assays. It is not the fraction that carries the risk, and its presence is no reason to treat the drug as benign.
Rutin
Flavonol glycosideConcentration: One of two flavonoids quantified in rat plasma after Farfarae Flos extract, the other being isoquercitrin
Absorbed at lower plasma concentrations than the phenolic acids after oral extract. Contributes to the antioxidant activity of the drug.
⚠ Drug Interactions
Hepatotoxic drugs and alcohol (paracetamol, methotrexate, isoniazid, azathioprine)
The drug contains 1,2-unsaturated pyrrolizidine alkaloids, which are hepatotoxic, genotoxic and carcinogenic, and it is restricted for that reason in several jurisdictions: use has been curtailed in Germany and Austria, German authorities capped daily intake of toxic pyrrolizidine alkaloids at 1 microgram, and the European Commission now sets maximum levels for these alkaloids in herbal infusions and food supplements. A PA-free registered clone, Tussilago farfara variety Wien, was bred in response so that pharmaceutical material could be supplied at all. Ordinary market material is not that clone. In the Chinese Pharmacopoeia survey the estimated daily intake from this herb at its recommended 10 g dose was 2.514 micrograms per kilogram body weight per day, some 359 times the 0.007 microgram per kilogram baseline used in the same assessment, giving a lifetime margin of exposure of 94.2 and, even assuming only two weeks of use per year for life, 2,450.7 - both far below the 10,000 that would indicate low concern. Adding a second hepatotoxin to that is indefensible.
Clinical note: Do not combine with other hepatotoxins or with regular alcohol. Do not give at all in pregnancy, breastfeeding, infancy, or existing liver disease. If used, insist on PA-assayed material, keep the course to days rather than weeks, and investigate weight gain, abdominal distension, ascites or right upper quadrant pain urgently.
CYP3A4 and CYP3A5 inducers (rifampicin, carbamazepine, phenytoin, St John's wort)
Toxification of 1,2-unsaturated pyrrolizidine alkaloids is a microsomal cytochrome P450 reaction with a preference for CYP2A6, CYP3A4 and CYP3A5, occurring in hepatocyte endoplasmic reticulum. The parent alkaloid is not itself the toxin; the pyrrolic ester it becomes is. Inducing those isoforms therefore increases, rather than clears, the hazard from a given dose.
Clinical note: Regard concurrent enzyme-inducing therapy as a contraindication rather than a caution.
Other pyrrolizidine alkaloid-containing herbs (Tu San Qi/Gynura japonica, Qian Li Guang/Senecio scandens, Zi Cao, comfrey, borage)
The harm is a function of cumulative 1,2-unsaturated alkaloid intake, not of any one herb. Gynura japonica is the identified culprit behind most pyrrolizidine alkaloid liver injury in China, and pyrrolizidine alkaloids were detectable in 271 of 386 pharmacopoeial Chinese herbs surveyed, at 0.1 to 25,567.4 micrograms per kilogram, so a formula can accumulate exposure from herbs no one regards as toxic. Honey and herbal teas add background intake on top.
Clinical note: Total the pyrrolizidine alkaloid sources across the whole prescription, including the ones present as contaminants rather than as intended ingredients.
Oral contraceptives, tamoxifen and other drugs associated with hepatic vascular injury
Pyrrolizidine alkaloid injury targets the liver sinusoidal endothelial cell specifically, producing sinusoidal obstruction syndrome rather than a hepatocellular hepatitis. Drugs independently associated with hepatic vascular and sinusoidal lesions act on the same compartment. No case series has tested the combination, so this is reasoning from mechanism rather than from data.
Clinical note: Note the theoretical basis and prefer avoidance; do not present this as a documented interaction.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 5–10 g | Daily | — | — | 中国药典 2020 【用法与用量】5～10g。 【性味与归经】辛、微苦，温。归肺经。 — 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.
Moistens the lungs and enriches yin while stopping cough, for chronic cough with blood-streaked sputum from yin deficiency.
Core pair of a classical formula — Bai Hua Gao, Ji Sheng Fang (Yan Yonghe)
Mutually reinforce moistening of the lungs, descending of qi and stopping of cough; one favors transforming phlegm, the other stopping cough.
Suited to cough of any kind, new or chronic, cold or heat.
Named pairing — Zhong Yao Xue national textbook, pei wu discussion
Evidence Tier
Strong 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
1
1 verified · 0 unverified
Randomized controlled trial
0
Other clinical trial
0
Observational / case report
0
In vitro / animal
3
0 verified · 3 unverified
Show 3 studies
- Tussilagone inhibits osteoclastogenesis by modulating mitochondrial function and ROS production involved Nrf2 activation
- Comparison of the difference in the anti-inflammatory activity of two different color types of Farfarae Flos based on in vitro, in vivo experiments and untargeted metabolomics
- Simultaneous Determination of Seven Phenolic Acids, Two Flavonoids, and Tussilagone in Rat Plasma after Administration of Farfarae Flos Extract by LC–MS/MS
Other / unclassified
2
0 verified · 2 unverified
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Determination of Toxic Pyrrolizidine Alkaloids in Traditional Chinese Herbal Medicines by UPLC-MS/MS and Accompanying Risk Assessment for Human Health
Analytical survey with a formal risk assessment across 386 herbs of the 2020 Chinese Pharmacopoeia. Pyrrolizidine alkaloids were found in 271 of them at 0.1 to 25,567.4 micrograms per kilogram. The Tussilago farfara sample carried 17,600.2 micrograms per kilogram across ten alkaloids led by senkirkine, senecionine N-oxide and senecionine; at the recommended 10 g daily dose that gives an estimated daily intake of 2.514 micrograms per kilogram body weight, a lifetime margin of exposure of 94.2, and 2,450.7 even on the generous assumption of two weeks of use per year. Both figures sit far below the margin of 10,000 conventionally taken to indicate low concern for a genotoxic carcinogen.
A systematic review and quality assessment of case reports of adverse events for borage (Borago officinalis), coltsfoot (Tussilago farfara) and comfrey (Symphytum officinale)
Systematic appraisal of the human case-report literature. Eleven reports met criteria and nine were assessable for causality, all showing some association between the material ingested and the adverse event, but botanical identification was so poor that attribution to coltsfoot specifically is unreliable: whole-herb misidentification and substitution, absent botanical verification, and attribution of an alkaloid to coltsfoot when it occurs in other toxic plants. The authors conclude the case series cannot settle the safety question either way. This is an argument that the human case literature is weak evidence, not that the alkaloid content or its measured margin of exposure is in doubt.
Content of pyrrolizidine alkaloids in the leaves of coltsfoot (Tussilago farfara L.) in Poland
Twenty samples from wild Polish populations, grown on at a medicinal plant garden near Poznan, were assayed for senkirkine and senecionine. Means were 0.19 plus or minus 0.11 and 0.23 plus or minus 0.18 micrograms per gram dry matter, total 0.42 plus or minus 0.26. This is leaf, the European drug, and it is three to four orders of magnitude below the pharmacopoeial Chinese flower-bud figure - a reminder that plant part, provenance and season decide the alkaloid load, and that no dose in grams predicts alkaloid exposure.
Tussilagone inhibits osteoclastogenesis by modulating mitochondrial function and ROS production involved Nrf2 activation
Tussilagone suppressed RANKL-induced osteoclast differentiation and bone resorption without cytotoxicity, lowering mitochondrial and intracellular reactive oxygen species and NFATc1 transcription while stabilising Nrf2; Nrf2 knockdown abolished the effect. It reduced bone loss in ovariectomised and lipopolysaccharide-treated mice. An isolated constituent in animals, not the herb in patients.
Comparison of the difference in the anti-inflammatory activity of two different color types of Farfarae Flos based on in vitro, in vivo experiments and untargeted metabolomics
Yellowish-white and purplish-red flower-bud types of the drug were compared in RAW 264.7 cells and in mice over seven days. Both suppressed interleukin-6, interleukin-10, tumour necrosis factor alpha and nitric oxide, the purplish-red type more strongly, and untargeted metabolomics identified 48 differentially accumulated compounds correlating with the activity. The finding matters mainly as evidence that two commercial grades of the same drug are not chemically equivalent.
Simultaneous Determination of Seven Phenolic Acids, Two Flavonoids, and Tussilagone in Rat Plasma after Administration of Farfarae Flos Extract by LC–MS/MS
Pharmacokinetics in rats given Farfarae Flos extract at 3.90 and 7.80 g per kg. Neochlorogenic, chlorogenic, cryptochlorogenic, caffeic and isochlorogenic acids A, B and C, plus rutin and isoquercitrin and tussilagone, all appeared in plasma with Tmax between 0.21 and 0.69 hours. Phenolic acids reached the highest Cmax and AUC; tussilagone was cleared fastest. Establishes which constituents are actually systemically available from the flower bud.
Historical Texts
Shen Nong Ben Cao Jing
Han dynasty, compiled by c. 200 CEMing Yi Bie Lu
Period of Division, c. 500 CEBen Cao Gang Mu
Ming dynasty, 1596References
- Chen S, Dong L, Quan H, Zhou X, Ma J, Xia W, Zhou H, Fu X. A review of the ethnobotanical value, phytochemistry, pharmacology, toxicity and quality control of Tussilago farfara L. (coltsfoot) . Journal of Ethnopharmacology (2021) [DOI]
- Teschke R, Vongdala N, Quan NV, Quy TN, Xuan TD. Metabolic Toxification of 1,2-Unsaturated Pyrrolizidine Alkaloids Causes Human Hepatic Sinusoidal Obstruction Syndrome: The Update . International Journal of Molecular Sciences (2021) [DOI]
- Lis-Cieplak A, Trześniowska K, Stolarczyk K, Stolarczyk EU. Pyrrolizidine Alkaloids as Hazardous Toxins in Natural Products: Current Analytical Methods and Latest Legal Regulations . Molecules (2024) [DOI]
- Wawrosch C, Kopp B, Wiederfield H. Permanent monitoring of pyrrolizidine alkaloid content in micropropagated Tussilago farfara L.: A tool to fulfill statutory demands for the quality of coltsfoot in Austria and Germany . Acta Horticulturae (2000) [DOI]
- Zhu L, Zhang CY, Li DP, Chen HB, Ma J, Gao H, Ye Y, Wang JY, Fu PP, Lin G. Tu-San-Qi (Gynura japonica): the culprit behind pyrrolizidine alkaloid-induced liver injury in China . Acta Pharmacologica Sinica (2021) [DOI]
- Kopp T, Abdel-Tawab M, Mizaikoff B. Extracting and Analyzing Pyrrolizidine Alkaloids in Medicinal Plants: A Review . Toxins (2020) [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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