Mao Zhao Cao
StarRanunculus ternatus Thunb.
Traditionally used for
- Cough & breathing
- Nerves & recovery
- Pain & joints
- Skin
☯ TCM Properties
Transforms Phlegm and Dissipates Nodules; Resolves Toxicity and Reduces Swelling; Disperses Accumulations and Dissipates Nodules
Traditional Chinese Uses
Mao Zhao Cao (Ranunculus ternatus, cat-claw buttercup) is a warm herb used in Chinese medicine to dissipate Phlegm nodules, disperse accumulations, and stop pain. It is applied for scrofula, lymph node swellings, thyroid nodules, and carbuncles from Phlegm-Fire stagnation, as well as for joint pain and neuralgia from obstruction. It has mild toxicity and must be used in controlled doses. Topically it is applied for skin conditions and inflammatory swellings.
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Botanical Description
Ranunculus ternatus is a small tuberous perennial herb in the Ranunculaceae, native to grassy fields, ditch banks, and damp slopes across central and southern China, Japan, and Korea. From a cluster of small, spindle-shaped to ovoid fleshy tubers 5-15 mm long arises a low rosette of long-petiolate basal leaves that are simple to ternately compound, with three obovate to broadly cuneate leaflets that are shallowly three-lobed or coarsely toothed at the apex, dark green and glabrous to sparsely hairy. One to a few slender flowering stems 5-20 cm tall bear small bright yellow five-petalled flowers about 8-10 mm across with numerous stamens and a domed receptacle. Fruits are small ovoid achenes aggregated into a head. The dried tuberous roots, dug in spring, are the medicinal Mao Zhao Cao.
Active Constituents
Ternatoside A and ternatoside B
Phenolic glycosidesConcentration: Minor constituents isolated from the tuberous root
The two glycosides described as new from the roots of this species and named after it, isolated alongside sternbin, methylparaben, 4-O-D-glucopyranosyl-p-coumaric acid and linocaffein. They are chemotaxonomic markers for the root drug rather than compounds with an established pharmacology.
Benzophenone derivatives - methyl and n-butyl (R)-3-[2-(3,4-dihydroxybenzoyl)-4,5-dihydroxyphenyl]-2-hydroxypropanoate
Polyhydroxylated benzophenonesConcentration: Minor constituents of the root
The compounds behind the anti-tuberculosis claim. The methyl ester showed activity against Mycobacterium tuberculosis in vitro, and a 1:1 mixture with gallic acid was more active than the ester alone. This is in vitro activity against a cultured organism, not evidence of clinical efficacy in tuberculosis.
Indolopyridoquinazoline alkaloidal glycosides
Quinazoline alkaloid glycosidesConcentration: Trace constituents of the root
An unusual alkaloid class for the Ranunculaceae, isolated from this species. Their significance is that they anchor the alkaloid fraction that later oncology work identified as the active one.
Total alkaloid fraction of the root
Mixed alkaloidsConcentration: Characterised as a fraction rather than as individual quantified compounds
In mouse colorectal cancer models the alkaloid fraction, not the glycoside or polysaccharide fractions, carried the anti-metastatic activity, suppressing epithelial-mesenchymal transition with MMP3 and CCL5 as the identified targets. This is the best-characterised activity of the drug and it is entirely preclinical.
Root polysaccharides
PolysaccharidesConcentration: A major fraction of the aqueous extract by mass
The fraction credited with the immunomodulatory and antioxidant activity reported in normal and immunosuppressed mice. It is the plausible basis of the traditional use in scrofula and chronic lymphadenopathy, and the reason the drug is a theoretical concern alongside immunosuppressant therapy.
Sternbin
FlavanoneConcentration: Minor constituent of the root
One of the known flavonoids recovered from the root in the phytochemical survey of the species. It is reported as a constituent without an attributed activity in this plant.
Vanillic acid and gallic acid
Phenolic acidsConcentration: Minor constituents of the root
Common phenolic acids, notable here only because gallic acid potentiated the anti-mycobacterial activity of the root's benzophenone when the two were tested together.
Ranunculin and its degradation products protoanemonin and anemonin
Glucoside of a gamma-hydroxy unsaturated lactone, and the vesicant lactone protoanemonin released from itConcentration: Not reported among the constituents isolated from the dried tuberous root, which is the medicinal drug; the genus as a whole carries ranunculin in fresh tissue and protoanemonin biosynthesis has been demonstrated in Ranunculus glaber Makino, a taxon of the ternatus complex
The reason this species is safe to take internally while its relatives are not. Ranunculin is enzymatically converted on tissue damage to protoanemonin, a volatile vesicant lactone that blisters skin and mucosa and is the toxin of the buttercup genus; on drying, protoanemonin dimerises to the far less irritant anemonin. Repeated phytochemical work on the dried tuberous root of R. ternatus has recovered glycosides, benzophenones, alkaloids and polysaccharides but not ranunculin, and this - the part used, and the fact that it is dried - is what separates the drug from Mao Gen. It is not a claim that the living plant lacks the biosynthetic pathway.
⚠ Drug Interactions
Mao Gen (Ranunculus japonicus) and other fresh Ranunculus species substituted or adulterated into Mao Zhao Cao
Mao Zhao Cao and Mao Gen are Ranunculus species with similar folk names, and Mao Gen (R. japonicus) is a recognised vesicant used externally as a blistering agent, never as an internal decoction. The difference is ranunculin: R. japonicus carries it, and on tissue damage it releases protoanemonin, which blisters skin and mucosa. Mao Zhao Cao's safety as an internal drug depends on being the dried tuberous root of R. ternatus specifically. Substitution in either direction is a substitution between a drug that is swallowed and a drug that raises blisters, and this corpus already carries the reciprocal warning on the Mao Gen record.
Clinical note: Insist on the tuberous root (Radix Ranunculi Ternati), properly dried, and reject aerial material or anything fresh. Refuse a batch that smells acrid or that causes tingling or blistering on handling. If a patient reports oral burning after a Mao Zhao Cao decoction, stop the formula and re-authenticate the batch rather than reducing the dose.
Anti-tuberculosis chemotherapy (isoniazid, rifampicin, pyrazinamide, ethambutol)
The traditional and modern Chinese indication for this drug is scrofula and lymph node tuberculosis, and its anti-tubercular reputation rests on in vitro inhibition of Mycobacterium tuberculosis by isolated benzophenones. There is no human trial evidence that the herb treats tuberculosis. Tuberculosis is curable only by prolonged multi-drug chemotherapy, and partial or interrupted treatment selects for resistance; the danger is not a pharmacokinetic interaction but a patient who substitutes or delays.
Clinical note: Never offer Mao Zhao Cao as an alternative to, or a reason to defer, standard anti-tuberculosis therapy, and say so explicitly to the patient. If used adjunctively, confirm the patient is under specialist TB care and is adherent, and report any new lymphadenopathy or systemic symptoms to that team rather than adjusting the herbal formula.
Ciclosporin, tacrolimus, azathioprine and other immunosuppressants
The root polysaccharide fraction is reported to enhance immune function in mice, which is the direction opposite to the intent of transplant and autoimmune immunosuppression. No human data exist and the animal work uses crude polysaccharide rather than a decoction, so this is a mechanistic caution rather than a documented interaction. It is worth stating because the drug's traditional indications - chronic lymphadenopathy, nodules - overlap with populations who may be on such therapy.
Clinical note: Avoid in transplant recipients and in patients on immunosuppression for autoimmune disease unless their specialist is informed. Watch for a change in disease activity rather than relying on drug levels, which this mechanism would not move.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 15–30 g | — | — | — | ChP 2025. 单味药可用至120g — up to 120 g when used as a single herb. Corrected from a generic 6-15g filler value generated from tcm_category; note the filler was too LOW here, not too high. |
Evidence Tier
Moderate evidence · 5 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
5
0 verified · 5 unverified
Show 5 studies
- Chemical Constituents from the Roots of Ranunculus ternatus and their Inhibitory Effects on Mycobacterium tuberculosis
- Ranunculus ternatus Thunb. alkaloids attenuate colorectal cancer metastasis through EMT suppression
- Chemical Constituents from the roots of Ranunculus ternatus
- Two New Indolopyridoquinazoline Alkaloidal Glycosides from Ranunculus ternatus
- New heterocyclic compounds from Ranunculus ternatus Thunb.
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
Some DOIs on this page have not been checked against the registries yet; their studies count as unverified until they are.
Clinical Studies
Chemical Constituents from the Roots of Ranunculus ternatus and their Inhibitory Effects on Mycobacterium tuberculosis
Two new benzophenones were isolated from the roots of Ranunculus ternatus along with vanillic acid and gallic acid. The methyl ester showed activity against Mycobacterium tuberculosis, and a 1:1 mixture with gallic acid was more active than the ester alone. This is the primary experimental basis for the drug's anti-tubercular reputation and it is a broth assay against cultured mycobacteria, not a clinical result.
Ranunculus ternatus Thunb. alkaloids attenuate colorectal cancer metastasis through EMT suppression
Fraction-guided work in HCT116 and CT26 cells and in ectopic and tail-vein-injection mouse models identified the alkaloid fraction as the anti-colorectal-cancer principle. The alkaloids suppressed epithelial-mesenchymal transition, lowered TGF-beta and CCL5 in tumour and serum, downregulated MMP3, MMP9 and beta-catenin and raised E-cadherin, and reduced distant metastasis. The authors state this is the first experimental evidence of an anti-metastatic effect for the species; there is no human evidence.
Chemical Constituents from the roots of Ranunculus ternatus
Phytochemical study of the root that named the two new glycosides ternatoside A and ternatoside B, alongside sternbin, methylparaben, 4-O-D-glucopyranosyl-p-coumaric acid and linocaffein. Relevant to the record mainly for what it does not contain: no ranunculin or protoanemonin was recovered from the dried root.
Two New Indolopyridoquinazoline Alkaloidal Glycosides from Ranunculus ternatus
Isolation and structure elucidation of two new indolopyridoquinazoline alkaloid glycosides from the species, establishing that this Ranunculus carries a quinazoline alkaloid series. Purely chemical, but it is the groundwork for the later identification of the alkaloid fraction as the pharmacologically active one.
New heterocyclic compounds from Ranunculus ternatus Thunb.
Further phytochemical characterisation of the species, adding new heterocyclic structures to its inventory. Included so the constituent list rests on more than one isolation campaign; it reports no pharmacological endpoint.
References
- Wang Changlin, Wang Jieqiong, Gao Mingzhou, Gao Peng, Gao Dongmei, Zhang Hao, Mu Xiangyu, Qiao Mingqi. Radix Ranunculi ternati: review of its chemical constituents, pharmacology, quality control and clinical applications . Journal of Pharmacy and Pharmacology (2022) [DOI]
- Sirak Betelhem, Aragaw Misgana, Tadesse Solomon. Ranunculin, Protoanemonin, and Anemonin: Pharmacological and Chemical Perspectives . Current Medicinal Chemistry (2025) [DOI]
- Suga Takayuki, Hirata Toshifumi. THE BIOSYNTHESIS OF PROTOANEMONIN IN RANUNCULUS GLABER MAKINO . Chemistry Letters (1973) [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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