Da Qing Ye
StarIsatis tinctoria
Synonyms: Isatis tinctoria var. pastoris
Traditionally used for
- Nose & throat
- Colds & fever
- Urinary & fluids
☯ TCM Properties
Clears Heat and resolves Fire toxicity; Cools the Blood and dissipates maculae; Cools Gallbladder Heat
Traditional Chinese Uses
Da Qing Ye (isatis leaf, woad leaf) is a cold, bitter herb that powerfully clears Heat toxin and cools the Blood. It is used for febrile illnesses with high fever, rashes, delirium, and bleeding from Blood Heat — particularly epidemic-type conditions where Heat toxin is intense and rapid in progression. It addresses swollen, painful throat, tonsillitis, and other upper respiratory infections from Heat toxin. Together with Ban Lan Gen (isatis root) from the same plant, it forms a complementary pair widely used for acute infections in Chinese medicine.
Western Herbalism Properties
Relationships
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Gallery
Botanical Description
Isatis tinctoria is a biennial or perennial herb in the mustard family (Brassicaceae), growing 50-130 cm tall. First-year plants form a basal rosette of oblong, glaucous (blue-green) leaves 10-30 cm long. Second-year stems are erect and branched, with smaller stem-clasping leaves. Small yellow flowers are produced in branched corymbs. The distinctive fruits are oblong, flat, pendulous, one-seeded, and dark when mature (resembling a tongue). Leaves are used for Da Qing Ye, roots for Ban Lan Gen.
Fields, roadsides, disturbed habitats, and rocky slopes; native to Eurasia, historically cultivated as a dye plant, now naturalized in many temperate regions. Grown commercially in China.
Isatis tinctoria is widely cultivated in China and naturalized throughout temperate regions. It is commonly grown for both medicinal and dye purposes. No conservation concerns, though wild populations may be less common in some areas.
Active Constituents
Indirubin
Bis-indole (indigoid) alkaloidConcentration: the Chinese Pharmacopoeia marker for Daqingye, required at not less than 0.020% of the dried leaf; in a 2025 Hong Kong market survey only 1 of 19 samples sold as Daqingye reached that limit
Indirubin is the isomer of indigo that carries most of the cytostatic and anti-inflammatory interest in this drug; it inhibits cyclin-dependent kinases and GSK-3beta, and it is the lead structure behind the semi-synthetic indirubin analogues developed for leukaemia. It is also the compound the Pharmacopoeia uses to decide whether a leaf sample is genuine Isatis at all.
Indigo (indigotin)
Indigoid pigmentConcentration: the blue pigment that gives the drug its name; commercial natural indigo prepared from Isatis tinctoria has been characterised as roughly 91% indigo with about 4% indirubin
Indigo is not present as such in the living leaf but forms from indican-type precursors on drying, fermentation or extraction, which is why harvest and processing change the assay result far more than they do for a simple alkaloid. It is the main constituent of the derived drug Qing Dai (indigo naturalis) rather than an independently potent agent.
Tryptanthrin
Indoloquinazoline alkaloidConcentration: a minor lipophilic constituent, concentrated in dichloromethane and supercritical CO2 leaf extracts rather than in water decoctions
Tryptanthrin was identified as the COX-2 inhibitory principle of lipophilic Isatis tinctoria leaf extracts. Importantly, in the same work the isolated compound showed no significant anti-inflammatory effect in carrageenan paw oedema or TPA ear oedema, so the in vivo activity of the extract cannot be attributed to tryptanthrin alone.
Epigoitrin (R-goitrin)
Thiooxazolidinone from glucosinolate hydrolysis (epiprogoitrin)Concentration: the Pharmacopoeia marker for the root drug Banlangen rather than for the leaf, required at not less than 0.020%; an authenticated root sample assayed at 0.023%
Epigoitrin and its enantiomer goitrin arise when the myrosinase enzyme acts on epiprogoitrin during processing. Goitrin is a well-characterised thyroid peroxidase inhibitor and the reason woad and its relatives are classed as goitrogenic plants; the antiviral activity claimed for Banlangen is attributed to the R-enantiomer.
Vicenin-2
Flavone C-glycoside (apigenin 6,8-di-C-glucoside)Concentration: reported together with isovitexin as the most abundant flavonoids in a hydroalcoholic leaf extract of European Isatis tinctoria
Vicenin-2 contributes to the radical-scavenging and anti-inflammatory profile of aqueous-alcoholic leaf preparations. It is a common Brassicaceae flavone and is not specific to Isatis, so it is a poor authentication marker even though it is quantitatively prominent.
Isatin
Oxindole alkaloidConcentration: trace constituent of the leaf and a degradation product of the indole precursors
Isatin is one of the indole-derived minor constituents repeatedly recovered from Isatidis Folium and is listed among the key components credited with the anti-inflammatory activity of indigo-type preparations.
Sinigrin and epiprogoitrin
GlucosinolatesConcentration: epiprogoitrin and indol-3-ylmethyl glucosinolate are the dominant glucosinolates of Chinese woad
These sulphur glycosides are the inert storage forms; on crushing or decoction they are hydrolysed by myrosinase to isothiocyanates and to goitrin, which is where both the pungency and the antithyroid potential of the drug come from.
⚠ Drug Interactions
Strobilanthes cusia / Baphicacanthus cusia (Nan Ban Lan Gen, Ma Lan) supplied as Da Qing Ye
A 2025 authentication survey of the Hong Kong market found that 16 of 19 samples sold as Daqingye and 17 of 18 sold as Banlangen were Strobilanthes species rather than Isatis, with one further Daqingye sample adulterated with Blumea balsamifera. The substituted material showed no epigoitrin peak at all and a distinctly different HPLC profile, so the Pharmacopoeia markers for Isatis are simply absent. Historically several unrelated plants were all sold as Da Qing Ye, including Baphicacanthus cusia, Polygonum tinctorium and Clerodendrum cyrtophyllum, and that regional habit persists in trade.
Clinical note: Specify Isatis tinctoria (Isatis indigotica) leaf when ordering, and ask the supplier for an indirubin assay. If the material is Strobilanthes, treat it as Nan Ban Lan Gen and do not assume the Isatis literature applies.
Levothyroxine, antithyroid drugs (carbimazole, propylthiouracil) and thyroid-function monitoring
Isatis is a Brassicaceae plant whose glucosinolate epiprogoitrin is hydrolysed to goitrin, a documented inhibitor of thyroid peroxidase that blocks iodine incorporation and lowers thyroxine synthesis. Goitrin content is high enough in the root that the Pharmacopoeia uses it as the identity marker, and the leaf shares the same glucosinolate pathway. No clinical case of Isatis-induced hypothyroidism has been reported, so this is a pharmacological inference rather than an observed interaction.
Clinical note: Short courses for acute febrile illness are the traditional use and are unlikely to matter. If the herb is used continuously for weeks in a patient on thyroid replacement or with known thyroid disease, check TSH rather than assuming no effect.
Radix Isatidis (Ban Lan Gen) preparations, where the leaf and root are treated as interchangeable
Isatis tinctoria yields two separate Pharmacopoeia drugs from the same plant: Isatidis Folium (Da Qing Ye, the leaf) and Isatidis Radix (Ban Lan Gen, the root). They are assayed against different markers, indirubin for the leaf and epigoitrin for the root, and the great majority of the modern antiviral and clinical literature, including the granule preparations sold for influenza, concerns the root. Reports of adverse reactions to oral and injectable Banlangen preparations, including hypersensitivity and haemolytic reactions, are likewise root data.
Clinical note: Do not transfer root trial data or root dosing to the leaf. When reading a study, check whether the material was Radix or Folium Isatidis before applying it.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 9–15 g | daily | — | adult | 中国药典 2020年版 一部 【大青叶】【用法与用量】9～15g。 — Chinese Pharmacopoeia 2020, Vol. I. |
Evidence Tier
Moderate evidence · 3 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
3
2 verified · 1 unverified
Show 3 studies
- Anti-Inflammatory and Antiallergic Activity in vivo of Lipophilic Isatis tinctoria Extracts and Tryptanthrin
- Hydroalcoholic Leaf Extract of Isatis tinctoria L. via Antioxidative and Anti-Inflammatory Effects Reduces Stress-Induced Behavioral and Cellular Disorders in Mice
- Tryptanthrin alleviate lung fibrosis via suppression of MAPK/NF-κB and TGF-β1/SMAD signaling pathways in vitro and in vivo
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
Anti-Inflammatory and Antiallergic Activity in vivo of Lipophilic Isatis tinctoria Extracts and Tryptanthrin
Supercritical CO2 and dichloromethane extracts of Isatis tinctoria leaf inhibited carrageenan-induced mouse paw oedema and TPA-induced mouse ear oedema after both oral and topical dosing, and the dichloromethane extract reduced oedema and neutrophil infiltration in a subchronic model. Tryptanthrin, previously identified as the COX-2 inhibitory principle, produced no significant effect on its own in these models, so the authors concluded the activity resides in other or multiple constituents. The plant material was European woad leaf, not Chinese Pharmacopoeia Daqingye.
Hydroalcoholic Leaf Extract of Isatis tinctoria L. via Antioxidative and Anti-Inflammatory Effects Reduces Stress-Induced Behavioral and Cellular Disorders in Mice
A 70% methanol leaf extract of European Isatis tinctoria was given intraperitoneally at 50, 100 and 500 mg/kg to CD-1 mice subjected to acute restraint stress, with bupropion 10 mg/kg as reference. The highest dose reversed stress-induced falls in locomotor activity and social interaction and reduced anxiety-like behaviour, alongside lower nitric oxide and plasma C-reactive protein. Vicenin-2 and isovitexin were the most abundant flavonoids in the extract. This is a parenteral animal study of a European accession and says nothing directly about oral decoctions of the Chinese drug.
Tryptanthrin alleviate lung fibrosis via suppression of MAPK/NF-κB and TGF-β1/SMAD signaling pathways in vitro and in vivo
Tryptanthrin, the indoloquinazoline alkaloid of Isatis tinctoria, reduced fibrotic and inflammatory markers in bleomycin-induced pulmonary fibrosis in mice and in matching cell models, acting through MAPK/NF-kappaB and TGF-beta1/SMAD signalling. The work uses the isolated compound at pharmacological doses, not the crude leaf, and tryptanthrin is a lipophilic constituent poorly extracted by the water decoction in which Da Qing Ye is normally given.
Historical Texts
Ming Yi Bie Lu
Six Dynasties, compiled c. 500 CE and attributed to Tao HongjingBen Cao Gang Mu
Ming dynasty, 1596Pharmacopoeia of the People's Republic of China
Modern, leaf and root listed separately since the 1985 editionReferences
- Chen J, Zhu Z, Gao T, Chen Y, Yang Q, Fu C, Zhu Y, Wang F, Liao W. Isatidis Radix and Isatidis Folium: A systematic review on ethnopharmacology, phytochemistry and pharmacology . Journal of Ethnopharmacology (2022) [DOI]
- Ngai HL, Cheng SW, Tse TS, Lee HK, Shaw PC. Quality assessment of medicinal material Daqingye and Banlangen from Isatis tinctoria Fort. reveals widespread substitution with Strobilanthes species . PLOS One (2025) [DOI]
- Hu Y, Chen LL, Ye Z, Li LZ, Qian HZ, Wu MQ, Wang J, Qin KH, Ye QB. Indigo naturalis as a potential drug in the treatment of ulcerative colitis: a comprehensive review of current evidence . Pharmaceutical Biology (2024) [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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