Zi Hua Di Ding
StarViola yedoensis Makino
Traditionally used for
- Colds & fever
- Skin
☯ TCM Properties
Clears Heat and Resolves Toxicity; Cools the Blood and reduces swelling; Resolves abscesses and disperses nodules
Traditional Chinese Uses
Zi Hua Di Ding (purple viola herb, violae herba) is a cold, bitter herb used in Chinese medicine to clear Heat toxin and reduce swellings. It is one of the five key herbs in the classical Heat-toxin-clearing formula Wu Wei Xiao Du Yin, used for carbuncles, furunculosis, and inflammatory skin abscesses. It also treats snakebite and bee sting toxicity, and some formulas use it for deep-Heat febrile conditions. Its focused Heat-toxin-clearing and anti-inflammatory action makes it a standard herb in skin and infection-related formulas.
Western Herbalism Properties
Relationships
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Botanical Description
Viola yedoensis (sometimes treated as a synonym of V. philippica), Yedo violet or Zi Hua Di Ding, is a low-growing perennial herb in the Violaceae family native to East Asia. The plant is stemless (acaulescent), forming a rosette 5-15 cm tall from a short rhizome with a cluster of fibrous roots. Leaves are basal, long-petiolate, narrowly oblong-lanceolate to triangular-ovate, 3-10 cm long, with finely toothed margins and a heart-shaped or truncate base. Solitary flowers 1-1.5 cm across on slender scapes are dark violet-purple with five petals, the lowest with a short spur, blooming in early to mid spring. Capsules are ellipsoid and three-valved.
Active Constituents
Esculetin (aesculetin, 6,7-dihydroxycoumarin)
Simple coumarinConcentration: the Chinese Pharmacopoeia marker compound for Herba Violae; quantified assay content varies widely with harvest and origin, so no single reliable figure can be given
Esculetin is the compound the Chinese Pharmacopoeia uses to identify and assay this drug, and reported reviews place V. yedoensis above other Viola species for esculetin content. It is antibacterial in vitro against Staphylococcus aureus and streptococci, with reported minimum inhibitory concentrations in the region of 0.03-0.31 g/L, and it inhibits NF-kB-driven cytokine release in inflammation models.
Esculin (aesculetin 6-O-glucoside)
Coumarin glycosideThe glucoside of esculetin and one of the main water-soluble coumarins of the decoction; it is hydrolysed to esculetin by gut flora, so it behaves largely as a pro-drug of the aglycone.
Dimeresculetin (euphorbetin-type dimeric coumarin)
Dimeric coumarinReported to prolong thrombin time markedly in vitro at around 100 micrograms/mL, which is the basis of the anticoagulant activity attributed to this herb. Note that this is a direct in vitro effect on the clotting cascade and is not vitamin K antagonism.
Scopoletin
Methoxylated coumarinA widely distributed coumarin isolated from the aerial parts, contributing to the anti-inflammatory and antibacterial activity attributed to the coumarin fraction.
Cycloviolacin Y5
Cyclotide (bracelet-type cyclic cystine-knot peptide)Isolated from V. yedoensis and among the most potent anti-HIV cyclotides described, with an EC50 of 0.04 microM in an XTT-based assay. Its selectivity is narrow: cytotoxicity to uninfected cells was seen at IC50 1.8 microM, and it was the most haemolytic of the cyclotides tested, which is a caution for any parenteral or injectable use of this material rather than for the decoction.
Cycloviolacin Y4
CyclotideA second anti-HIV cyclotide from the same herb, EC50 0.12 microM with cytotoxicity at IC50 1.7 microM. Cyclotides are heat- and protease-stable, so they survive decoction, but they are large peptides and oral absorption is not established.
Varv E and kalata B1
CyclotideTwo previously known cyclotides also present in V. yedoensis, with anti-HIV EC50 values of 0.35 and 0.66 microM respectively. Their presence is one of the chemical markers that separates Viola material from the unrelated drugs sold under the same Di Ding name.
Yedoensins A and B
SesquiterpeneSesquiterpenes described as unique to this species; reported among the constituents with anti-complement activity. They are useful chemotaxonomic markers for authenticating Viola yedoensis material.
Apigenin, luteolin and their glycosides
FlavoneThe main flavones of the herb, mostly present as glucosides and arabinosides. They account for a large part of the anti-inflammatory activity seen in macrophage assays of V. yedoensis extracts.
Protocatechuic acid
Phenolic acidA simple phenolic acid reported at its highest level in this species among the Viola studied; antioxidant and mildly antibacterial.
Oleanolic acid and ursolic acid
Pentacyclic triterpenoidCommon plant triterpenoids present in the aerial parts, with anti-inflammatory and hepatoprotective activity in cell and animal models.
⚠ Drug Interactions
Ku Di Ding (Corydalis bungeana) and other Di Ding substitutes
Several unrelated plants are traded in China under a Di Ding name: Zi Hua Di Ding is Viola yedoensis, Ku Di Ding is Corydalis bungeana (an isoquinoline-alkaloid-bearing Papaveraceae), and further material is sold as Di Ding from Gentiana species. Viola contains coumarins, flavonoids and cyclotides and no alkaloid load of consequence, whereas Corydalis bungeana material carries corynoline-type alkaloids. Receiving one when the prescription intended the other changes the pharmacology of the whole formula.
Clinical note: Specify Herba Violae or Viola yedoensis on the prescription rather than Di Ding alone, and check that the supplied material matches the Pharmacopoeia description. Esculetin is the Pharmacopoeia assay marker and its absence is a red flag for substituted material.
Warfarin, direct oral anticoagulants and antiplatelet drugs
Coumarins from this herb, principally dimeresculetin and esculetin, prolong thrombin time and affect several coagulation pathways in vitro. This is a direct in vitro effect at concentrations far above anything demonstrated after an oral dose, and it is not the vitamin K epoxide reductase mechanism of warfarin, so the two are not pharmacologically equivalent. No human interaction has been reported.
Clinical note: No specific action is required at normal decoction doses, but if a patient on an anticoagulant is taking large or prolonged doses, monitor INR or for unusual bruising as you would with any new herb.
Injectable or parenteral Viola preparations
Cycloviolacin Y5 and related cyclotides from V. yedoensis are membrane-disrupting peptides and were the most haemolytic compounds in the human erythrocyte assay used in their original isolation. This is a property of the isolated peptides in direct contact with red cells and has no bearing on the traditional oral decoction, but it is a real concern for any injectable formulation of this plant.
Clinical note: Use this herb orally or topically as tradition and the Pharmacopoeia direct. Treat any injectable Viola preparation as unvalidated.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 15–30 g | Daily | — | — | 中国药典 2020 【用法与用量】15～30g。 【性味与归经】苦、辛，寒。归心、肝经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
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
1 verified · 2 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
Anti-HIV Cyclotides from the Chinese Medicinal Herb Viola yedoensis
Isolated eight cyclotides from Viola yedoensis, five of them new (cycloviolacins Y1-Y5), alongside kalata B1, varv A and varv E. In XTT-based anti-HIV assays cycloviolacin Y5 was the most potent at EC50 0.04 microM, with cycloviolacin Y4 at 0.12 microM and varv E at 0.35 microM. Cytotoxicity to uninfected cells was in the 1.7-5.7 microM range, so the therapeutic window is narrow, and cycloviolacin Y5 was the most haemolytic peptide tested.
Anti-inflammatory effects of Viola yedoensis and the application of cell extraction methods for investigating bioactive constituents in macrophages
An ethanol extract of Viola yedoensis suppressed nitric oxide and pro-inflammatory cytokine production in LPS-stimulated macrophages, and the authors used a cell-extraction approach to identify which constituents actually enter the cells and account for the effect. Supports the classical use for Heat-toxin sores at the level of macrophage inflammation, but this is cell-culture work and not clinical evidence.
Study on antibacterial active components from Viola yedoensis
A Chinese-language study tracing the antibacterial activity of Viola yedoensis to specific fractions and identifying coumarins as the principal antibacterial constituents. Cited widely as the basis for attributing the herb's antibacterial reputation to its coumarin fraction rather than to its flavonoids.
Historical Texts
Ben Cao Gang Mu
Ming dynasty (1596)Yi Zong Jin Jian (Golden Mirror of the Medical Tradition)
Qing dynasty (1742)References
- Wang S, Shen C, Zhang S, Di H, Wang Y, Guan F. A Comprehensive Review of the Phytochemistry and Therapeutic Efficacy of Viola yedoensis Makino . Molecules (2025) [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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