Bai Tou Weng
StarPulsatilla chinensis (Bge.) Regel
Traditionally used for
- Digestion
- Bowel health
- Menstrual & women's health
- Skin
Cautions & contraindications
- Liver conditions
☯ TCM Properties
Clears Heat and Resolves Toxicity; Cools the Blood and Stops Dysentery; Dries Dampness and kills parasites
Traditional Chinese Uses
Bai Tou Weng (白头翁) is the root of Pulsatilla chinensis (Bge.) Regel (Ranunculaceae), Radix Pulsatillae — the name, "white-headed old man", describes the silvery plumed fruiting head. It is bitter and cold, entering the Stomach and Large Intestine channels. It clears Heat and resolves toxicity, cools the Blood to stop dysentery, and dries Dampness and kills parasites.
It is the chief herb for hot dysenteric disorder with blood — stool containing blood and pus, severe tenesmus, burning of the anus and abdominal pain — and it heads Bai Tou Weng Tang with Huang Lian, Huang Bai and Qin Pi. It has a particular reputation in amoebic and bacillary dysentery. It is also decocted as a wash for Damp-Heat vaginal discharge and genital itching, and used for hot swollen sores.
Because it works by cooling and draining, it is inappropriate in dysenteric disorders of the deficient, cold type and in Spleen and Stomach deficiency Cold.
Western Herbalism Properties
Relationships
Full-screen graph →Click a node for details · double-click to expand it · Ctrl/⌘ + scroll or two fingers to zoom and pan.
Botanical Description
Pulsatilla chinensis (Chinese pasqueflower) is a low-growing perennial herb in the Ranunculaceae family, 15-35 cm tall, native to dry hillsides and grasslands across northern and central China, Korea, and the Russian Far East. It arises from a stout, dark brown, cylindrical taproot 5-20 cm long whose crown bears a conspicuous tuft of long, persistent, silvery-white silky hairs. The basal leaves are long-petioled, palmately divided into three deeply lobed segments, softly silky-pubescent especially when young. A single nodding bell-shaped flower 3-4 cm across is borne on each densely white-hairy scape; the six petaloid sepals are violet to deep purple, with numerous yellow stamens. The fruit is a head of long-tailed, plumose achenes (POWO; Wikipedia).
Active Constituents
Anemoside B4 (pulchinenoside C)
Oleanane-type triterpenoid saponinConcentration: the most abundant saponin of the root; the Chinese Pharmacopoeia sets the marker limit for decoction pieces at not less than 4.6% of the dried drug
The official quality-control marker for Pulsatillae Radix and the compound behind most of the drug's documented anti-inflammatory and immune-modulatory activity. It is poorly absorbed and undergoes only modest hepatic first-pass extraction (about 27% in rat), so much of an oral dose reaches the colon intact, which fits its traditional use in dysenteric disorders.
Anemoside A3
Oleanane-type triterpenoid saponinA minor companion saponin measured alongside anemoside B4 in pharmacokinetic work on Pulsatilla chinensis saponin extracts. It is used as a secondary chemical marker rather than as a compound with a well-characterised action of its own.
Pulsatilla saponin D
Hederagenin-based triterpenoid saponinThe most cytotoxic of the Pulsatilla saponins in cell work, but also the most haemolytic: in Journal of Natural Products work its cytotoxicity and its lysis of erythrocytes track together, and derivatisation was needed to separate them. It is the main reason crude saponin fractions from this root cannot be given parenterally.
Pulsatilla saponin A
Triterpenoid saponinA structurally related root saponin used as the scaffold for semisynthetic derivatives; the parent compound is both cytotoxic and haemolytic in vitro.
23-Hydroxybetulinic acid
Lupane-type triterpene (aglycone)A free triterpene acid of the root. In rat pharmacokinetics it showed the highest liver exposure of the three main markers, with a hepatic first-pass effect around 71%, so it is the constituent most concentrated in the liver after an oral dose.
⚠ Drug Interactions
Hepatotoxic drugs and other liver stressors (e.g. paracetamol, methotrexate, alcohol)
Long-term oral dosing of Pulsatilla chinensis saponins to rats produced chronic liver injury; serum metabonomics attributed it to disturbance of the ceramide/sphingomyelin balance with downstream dysregulation of lipid metabolism and hepatocyte apoptosis. The evidence is animal, not clinical, and concerns concentrated saponin extracts rather than short courses of the crude decoction.
Clinical note: Keep courses short, as classical practice does. Avoid concentrated Pulsatilla saponin extracts alongside known hepatotoxins, and monitor liver enzymes if the herb is used for more than a few weeks or in patients with existing liver disease.
P-glycoprotein and CYP3A substrates (e.g. florfenicol, digoxin, ciclosporin)
In broiler chickens, anemoside B4 changed the pharmacokinetics of florfenicol and altered hepatic mRNA expression of the xenobiotic receptor CXR and of MDR1, CYP3A37 and UGT1E. Avian CYP3A37 and CXR are not the human enzymes, so this establishes only that the saponin can engage the transporter and nuclear-receptor machinery; no human interaction study exists.
Clinical note: No action needed for ordinary decoction use. Treat with caution alongside narrow-therapeutic-index P-glycoprotein substrates such as digoxin, and report any unexpected change in drug levels.
Injectable and parenteral preparations of Pulsatilla saponins
Crude Pulsatilla chinensis saponins lyse erythrocytes in vitro: about 15.4% haemolysis of 0.5% rabbit red cells at 500 micrograms/mL and 7.4% at 250 micrograms/mL, and Pulsatilla saponin D is directly haemolytic. This is a general amphiphilic-saponin membrane effect and is the reason the drug is an oral and topical medicine, not an injectable one.
Clinical note: Never use crude root extracts by any parenteral route. The haemolytic risk is not relevant to normal oral decoctions, where the saponins are poorly absorbed.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 9–15 g | Daily | — | — | 中国药典 2020 【用法与用量】9～15g。 【性味与归经】苦，寒。归胃、大肠经。 — 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.
Together they clear heat, dry damp, cool the blood and stop dysentery, targeting heat-toxin dysentery with blood and pus.
Core pair of a classical formula — Bai Tou Weng Tang, Shang Han Lun (Zhang Zhongjing)
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
4 verified · 1 unverified
Show 5 studies
- Anti-inflammatory and immune-modulatory properties of anemoside B4 isolated from Pulsatilla chinensis in vivo
- Pulsatilla chinensis Saponins Ameliorate Inflammation and DSS-Induced Ulcerative Colitis in Rats by Regulating the Composition and Diversity of Intestinal Flora
- Safety investigation of Pulsatilla chinensis saponins from chronic metabonomic study of serum biomedical changes in oral treated rat
- Cytotoxicity, Hemolytic Toxicity, and Mechanism of Action of Pulsatilla Saponin D and Its Synthetic Derivatives
- Effects of anemoside B4 on pharmacokinetics of florfenicol and mRNA expression of CXR, MDR1, CYP3A37 and UGT1E in broilers
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 immune-modulatory properties of anemoside B4 isolated from Pulsatilla chinensis in vivo
Anemoside B4 purified from Pulsatilla chinensis suppressed inflammation in mouse models and modulated immune-cell responses, supporting the saponin fraction as the anti-inflammatory principle of the root rather than a phenolic or alkaloid component.
Pulsatilla chinensis Saponins Ameliorate Inflammation and DSS-Induced Ulcerative Colitis in Rats by Regulating the Composition and Diversity of Intestinal Flora
In rats with dextran sulfate sodium colitis, Pulsatilla chinensis saponins reduced colonic inflammation and shifted the composition and diversity of the gut microbiota. This is the closest mechanistic evidence for the classical use of Bai Tou Weng in damp-heat dysenteric disorders, but it remains an animal model.
Safety investigation of Pulsatilla chinensis saponins from chronic metabonomic study of serum biomedical changes in oral treated rat
Chronic oral administration of Pulsatilla chinensis saponins to rats produced liver injury. Serum metabonomics implicated disruption of the ceramide/sphingomyelin balance and bile-acid-mediated sphingolipid signalling, with consequent lipid dysregulation and apoptosis. The authors conclude that long-term safety of the saponin fraction needs further attention.
Cytotoxicity, Hemolytic Toxicity, and Mechanism of Action of Pulsatilla Saponin D and Its Synthetic Derivatives
Pulsatilla saponin D was both cytotoxic to tumour cell lines and haemolytic to erythrocytes; semisynthetic derivatives were used to probe whether the two activities could be separated. Documents the membrane-lytic hazard that rules out parenteral use of the crude saponins.
Effects of anemoside B4 on pharmacokinetics of florfenicol and mRNA expression of CXR, MDR1, CYP3A37 and UGT1E in broilers
Anemoside B4 altered florfenicol pharmacokinetics in broiler chickens and changed hepatic expression of CXR, MDR1, CYP3A37 and UGT1E, indicating that the marker saponin can engage drug-transporter and drug-metabolising machinery. Avian enzymes differ from human ones, so the finding is a flag rather than a quantified human interaction.
Historical Texts
Shen Nong Ben Cao Jing
Han dynastyShang Han Lun
Han dynastyReferences
- Jinmiao Zhong, Lihua Tan, Meiwan Chen, Chengwei He. Pharmacological activities and molecular mechanisms of Pulsatilla saponins . Chinese Medicine (2022) [DOI]
- Yan-hong Li, Min Zou, Qian Han, Li-rong Deng, Richard M. Weinshilboum. Therapeutic potential of triterpenoid saponin anemoside B4 from Pulsatilla chinensis . Pharmacological Research (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.
📝 Notes
Public notes from the community and your own private notes on Bai Tou Weng.
No notes yet.