Traditionally used for
- Nose & throat
- Cough & breathing
- Digestion
- Pain & joints
- Skin
☯ TCM Properties
Clears Heat and removes toxicity; Expels Wind and alleviates pain; Cools the Blood and stops bleeding
Traditional Chinese Uses
Bai Yao Zi is the tuberous root of Stephania cepharantha (Menispermaceae). A bitter, pungent, cool herb entering the Spleen, Lung and Kidney channels, it clears Heat and resolves Fire toxicity, dispels Wind and alleviates pain, and cools the Blood to stop bleeding. Traditional indications include swollen sore throat and mumps, sores, boils and abscesses (taken internally and applied externally as a crushed poultice), coughing or vomiting of blood and nosebleed from Blood-Heat, painful obstruction (Bi) from Wind-Damp, and traumatic injury. It is usually decocted, powdered, or macerated in wine, with the fresh root pounded for topical use on toxic swellings and snakebite.
Relationships
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Botanical Description
Bai Yao Zi is the tuberous root of Stephania species, principally Stephania cepharantha and the closely related S. tetrandra, both perennial climbing vines of the family Menispermaceae native to southern China and adjacent parts of East Asia. The plant arises from a large, irregularly globose to elongate underground tuber that may weigh several kilograms in mature specimens and is the medicinally collected part. Slender, twining herbaceous stems climb to 2 to 4 metres, bearing alternate, peltate, broadly ovate to nearly round leaves with the petiole inserted within the blade and palmate venation radiating from that point. Small, dioecious, greenish-yellow flowers are borne in umbel-like cymes in the leaf axils, followed by small, flattened, red drupes. The plants favour shaded slopes, thickets, and forest margins from low elevations to about 1500 metres.
Active Constituents
Cepharanthine
Bisbenzylisoquinoline (biscoclaurine) alkaloidConcentration: the principal alkaloid of the tuber; an HPLC study measured about 0.53% in a crude tuber extract, rising to about 2.9% after enrichment to a total-alkaloid fraction
The compound that defines this species and takes its name from it. It is antioxidant, anti-inflammatory, immunomodulatory, antitumour and antiviral in preclinical work, and it stabilises plasma-membrane fluidity, which is proposed as one of its antiviral mechanisms. It has been an approved medicine in Japan since the 1950s (Cepharanthin) for radiation-induced leukopenia and for alopecia areata, so unlike most TCM constituents it has a defined human dosing history, in the range of 1 to 60 mg daily.
Cycleanine
Bisbenzylisoquinoline alkaloidOne of the major bisbenzylisoquinoline alkaloids of the tuber alongside cepharanthine, and one of the alkaloids produced by callus and tuber tissue of this species.
Isotetrandrine
Bisbenzylisoquinoline alkaloidA stereoisomeric relative of tetrandrine, the marker alkaloid of Stephania tetrandra. Its presence is one reason chemical profiles of the two Stephania drugs overlap and why alkaloid detection alone does not confirm which species has been supplied.
Berbamine
Bisbenzylisoquinoline alkaloidA bisbenzylisoquinoline alkaloid recovered from tuber and callus tissue of S. cepharantha. It is widely distributed in the Menispermaceae and Berberidaceae and is not specific to this species.
Aromoline and homoaromoline
Bisbenzylisoquinoline alkaloidsTwo further bisbenzylisoquinolines identified in the tuber and callus-derived roots of S. cepharantha, part of the roughly forty alkaloids characterised from extracts of this species.
Morphinane and hasubanane alkaloids
Isoquinoline-derived alkaloidsSix morphinane and five hasubanane alkaloids were isolated from the tuber of S. cepharantha cultivated in Japan. These skeletons distinguish S. cepharantha chemically from Stephania tetrandra, whose profile is dominated by tetrandrine-type bisbenzylisoquinolines.
⚠ Drug Interactions
Aristolochia fangchi and other aristolochic-acid-containing roots substituted within the Fang Ji / Stephania trade group
The documented catastrophe involved Stephania tetrandra (Han Fang Ji), not S. cepharantha: in a Brussels slimming clinic in the early 1990s the Stephania material was replaced by Aristolochia fangchi (Guang Fang Ji) because the two pinyin names are similar, and more than 100 cases of rapidly progressive interstitial nephritis followed, about 5% of those exposed, with urothelial carcinoma reported in the cohort in the New England Journal of Medicine in 2000. The relevance to Bai Yao Zi is that the name Fang Ji is applied to roots from at least four genera, that S. tetrandra is morphologically similar to A. fangchi, and that S. cepharantha is a Stephania tuber traded in the same channels and readily confused with other Stephania species. I found no report of aristolochic acid detected in authenticated S. cepharantha itself; the hazard is one of supply-chain misidentification, not of the species' own chemistry.
Clinical note: Buy only from suppliers who authenticate to species and test for aristolochic acids. Aristolochic-acid botanicals are prohibited in most jurisdictions. Never accept material labelled only with a pinyin name in the Fang Ji group, and never substitute Bai Yao Zi for, or accept it in place of, Han Fang Ji or Guang Fang Ji.
P-glycoprotein substrates (e.g. digoxin, ciclosporin, vinblastine, daunorubicin, paclitaxel)
Cepharanthine is both a substrate and a potent inhibitor of P-glycoprotein. In the classic Journal of Pharmacology and Experimental Therapeutics study it inhibited P-glycoprotein-mediated transport of vinblastine and daunorubicin, with a 50% inhibitory concentration of 2.06 micromolar against daunorubicin transport. Later work shows cepharanthine hydrochloride reverses MDR1-mediated multidrug resistance in ovarian and oesophageal carcinoma lines and downregulates MDR1 mRNA and protein. This is a deliberate therapeutic property in oncology, but in an unsupervised herbal context it means efflux-limited drugs can accumulate.
Clinical note: Take particular care with digoxin and with oral chemotherapy. Where a patient is on a narrow-therapeutic-index P-glycoprotein substrate, separate the herb or avoid it, and involve the prescribing physician rather than adjusting doses independently.
Anticancer drugs subject to MRP7 (ABCC10)-mediated resistance
Cepharanthine is reported as a potent reversal agent for MRP7 (ABCC10)-mediated multidrug resistance as well as for P-glycoprotein, so its transporter effects are not confined to a single efflux pump. The consequences for normal-tissue drug distribution during chemotherapy have not been characterised in patients.
Clinical note: Do not add this herb to an active chemotherapy regimen without oncology input, whatever its reputation as a resistance-reversal agent.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | Dose not established here — see note | — | — | — | No Chinese Pharmacopoeia 2025 monograph found for this drug, so no pharmacopoeial dose is given here. *Stephania cepharantha*. Hepatotoxicity has been reported with prolonged use of Stephania-derived drugs, and the genus has a serious adulteration history: *Stephania* material substituted with *Aristolochia fangchi* caused an epidemic of aristolochic-acid nephropathy and urothelial cancer in Belgium. Verify botanical identity before dispensing. The previous value was generic filler generated from tcm_category and was cleared; it has not been replaced with an estimate. |
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
0 verified · 3 unverified
Show 3 studies
- Cepharanthin, a multidrug resistant modifier, is a substrate for P-glycoprotein.
- High Performance Liquid Chromatography Determination and Optimization of the Extraction Process for the Total Alkaloids from Traditional Herb Stephania cepharantha Hayata
- New Morphinane and Hasubanane Alkaloids from Stephania cepharantha
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
Cepharanthin, a multidrug resistant modifier, is a substrate for P-glycoprotein.
Cepharanthine was shown to be a P-glycoprotein substrate that potently inhibits the transporter, blocking vinblastine and daunorubicin transport with a 50% inhibitory concentration of 2.06 micromolar against daunorubicin. The quantitative basis for treating this herb as a P-glycoprotein interaction risk.
High Performance Liquid Chromatography Determination and Optimization of the Extraction Process for the Total Alkaloids from Traditional Herb Stephania cepharantha Hayata
Quantified cepharanthine in S. cepharantha material by HPLC and optimised its extraction, reporting roughly 0.53% cepharanthine in the crude extract (crude extract yield 18.6%) and about 2.9% after macroporous-resin enrichment to a total-alkaloid fraction of 3.4% yield.
New Morphinane and Hasubanane Alkaloids from Stephania cepharantha
Isolated six morphinane and five hasubanane alkaloids from tubers of S. cepharantha cultivated in Japan, establishing alkaloid classes that help distinguish this species chemically from other Stephania used under Fang Ji-type names.
Historical Texts
Xin Xiu Ben Cao (Tang Ben Cao)
Tang dynastyBen Cao Gang Mu
Ming dynastyReferences
- Christian Bailly. Cepharanthine: An update of its mode of action, pharmacological properties and medical applications . Phytomedicine (2019) [DOI]
- Di Liang, Qi Li, Lina Du, Guifang Dou. Pharmacological Effects and Clinical Prospects of Cepharanthine . Molecules (2022) [DOI]
- Moshe Rogosnitzky, Paul Okediji, Igor Koman. Cepharanthine: a review of the antiviral potential of a Japanese-approved alopecia drug in COVID-19 . Pharmacological Reports (2020) [DOI]
- Vaishali C. Joshi, Bharathi Avula, Ikhlas A. Khan. Authentication of Stephania tetrandra S. Moore (Fang Ji) and differentiation of its common adulterants using microscopy and HPLC analysis . Journal of Natural Medicines (2007) [DOI]
- Sidonie Tankeu, Ilze Vermaak, Weiyang Chen, Maxleene Sandasi, Alvaro Viljoen. Differentiation between two fang ji herbal medicines, Stephania tetrandra and the nephrotoxic Aristolochia fangchi, using hyperspectral imaging . Phytochemistry (2016) [DOI]
- J. L. Nortier, M. C. Martinez, H. H. Schmeiser, V. M. Arlt, C. A. Bieler, M. Petein, M. F. Depierreux, L. De Pauw, D. Abramowicz, P. Vereerstraeten, J. L. Vanherweghem. Urothelial Carcinoma Associated with the Use of a Chinese Herb (Aristolochia fangchi) . New England Journal of Medicine (2000) [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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