Huai Hua
StarStyphnolobium japonicum (L.) Schott
Traditionally used for
- Headaches
- Eye health
- Bowel health
- Blood pressure
☯ TCM Properties
Cools the Blood and Stops Bleeding; Clears Liver Fire; Clears Heat and Stops Diarrhea
Traditional Chinese Uses
Huai Hua (sophora flower, pagoda tree flower) is a bitter, slightly cold herb with a primary affinity for the Large Intestine channel, where it cools Blood Heat to stop bleeding. It is used for hemorrhoidal bleeding, rectal bleeding, and bloody dysentery from Damp-Heat in the Large Intestine, as well as for hemoptysis and epistaxis from Blood Heat. Its Liver-calming action also addresses Heat-related headache, red eyes, and elevated blood pressure. It is one of the most important herbs in the "cooling and stopping bleeding" category.
Western Herbalism Properties
Relationships
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Botanical Description
Styphnolobium japonicum, the Japanese pagoda tree or Chinese scholar tree (formerly Sophora japonica), is a deciduous tree in the Fabaceae, native to China and Korea and long cultivated throughout temperate East Asia. It grows 10 to 25 meters tall, with a broadly rounded crown, dark grey to brown bark that becomes deeply furrowed with age, and smooth, slightly glaucous green young twigs. The pinnately compound leaves are 15 to 25 cm long, bearing 7 to 17 ovate to ovate-lanceolate leaflets 2.5 to 6 cm long, dark green and glabrous above, paler and finely pubescent beneath. The inflorescence is a large, terminal panicle 15 to 30 cm long, appearing in late summer and bearing many fragrant, papilionaceous, creamy-white to pale yellow flowers about 1 to 1.5 cm long. The fruit is an unusual, fleshy, indehiscent, somewhat moniliform pod 2.5 to 8 cm long with constrictions between the seeds, green at first then drying to brown. The dried unopened flower bud (Huai Hua Mi) and fruit (Huai Jiao) are both used medicinally.
Active Constituents
Rutin (quercetin-3-O-rutinoside)
Flavonol glycosideConcentration: the Chinese Pharmacopoeia requires not less than 8.0% in the opened flower (Huai Hua) and not less than 20.0% in the unopened bud (Huai Mi); the European Pharmacopoeia sets not less than 6.0% rutin and 8.0% total flavonoids expressed as rutin
The dominant constituent by mass and the marker compound for the drug. Rutin reduces capillary fragility and permeability, which is the pharmacological correlate of the traditional indication for bleeding from the lower orifices. It is also a protein disulfide isomerase inhibitor with antithrombotic activity in animal thrombosis models, an action that sits awkwardly alongside the herb's haemostatic reputation and is the main reason to think about anticoagulant co-medication.
Quercetin
Flavonol aglyconeConcentration: reported at about 2.8% of Flos Sophorae Immaturus under optimised extraction, and increased at the expense of rutin by roasting or stir-frying
The aglycone released when rutin is hydrolysed, including by dry-frying the herb. Quercetin is antioxidant and anti-inflammatory and is the constituent behind most of the theoretical CYP and P-glycoprotein interaction concerns for this herb.
Narcissoside (isorhamnetin-3-O-rutinoside)
Flavonol glycosideConcentration: reported at about 7.2% of Flos Sophorae Immaturus under optimised extraction
The second most abundant flavonol glycoside of the bud, contributing to the total flavonoid load and to antioxidant activity.
Nicotiflorin (kaempferol-3-O-rutinoside)
Flavonol glycosideConcentration: reported at about 2.9% of Flos Sophorae Immaturus under optimised extraction
A kaempferol rutinoside contributing to the vascular and antioxidant activity of the flower bud.
Isorhamnetin
Methylated flavonol aglyconeA minor aglycone released on hydrolysis of narcissoside; antioxidant and anti-inflammatory in vitro.
Sophoricoside
Isoflavone glycosideAn isoflavone glycoside of Styphnolobium japonicum, most abundant in the fruit but also reported in the flower material. Its aglycone genistein is a phytoestrogen, which is the basis for caution in hormone-sensitive conditions.
Genistein
Isoflavone aglyconeA phytoestrogen and tyrosine kinase inhibitor, present as the aglycone of sophoricoside. Its oestrogenic activity is the reason to record a theoretical interaction with hormonal therapy.
⚠ Drug Interactions
Warfarin and other vitamin K antagonists
Two opposing pulls exist. Rutin, which makes up 8-20% of this drug by weight, is an inhibitor of protein disulfide isomerase and was shown in mouse thrombosis models to block thrombus formation, so a therapeutic dose of Huai Hua delivers a gram-scale dose of a compound with demonstrated antithrombotic activity. Against that, the herb is used traditionally to stop bleeding and quercetin has in vitro inhibitory activity at CYP2C9, the enzyme clearing S-warfarin. Neither effect has been measured in anticoagulated patients taking Huai Hua, so the direction and size of any clinical change is unknown.
Clinical note: Check INR within one to two weeks of starting or stopping the herb in any patient on a vitamin K antagonist, and again if the dose or the preparation (raw versus charred) changes.
Antiplatelet drugs (aspirin, clopidogrel) and direct oral anticoagulants
Extrapolated from the antithrombotic activity of rutin as a thiol isomerase inhibitor in preclinical models. There is no published human bleeding event attributable to Huai Hua, and no pharmacodynamic study in patients on antiplatelet therapy.
Clinical note: No action needed beyond ordinary vigilance for bruising or bleeding; do not withhold the herb on this basis alone.
CYP3A4 substrates and P-glycoprotein substrates with a narrow therapeutic index (e.g. ciclosporin, digoxin)
Quercetin, released from rutin by gut microbial and enteric hydrolysis and enriched by dry-frying the herb, inhibits CYP3A4 and P-glycoprotein in vitro. Whether the quercetin exposure achieved from a 5-10 g decoction of Huai Hua reaches interacting concentrations in vivo has not been tested.
Clinical note: Worth noting in a transplant or digoxin patient; monitor levels rather than avoid the herb outright.
Hormonal therapy in oestrogen-sensitive disease (tamoxifen, aromatase inhibitors, HRT)
The genus contributes the isoflavone sophoricoside and its phytoestrogenic aglycone genistein. Isoflavone content of the flower is far lower than of the fruit, and no clinical interaction has been reported with Huai Hua specifically.
Clinical note: Low priority. Record the exposure in patients on endocrine therapy for breast cancer rather than treating it as a contraindication.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 5–10 g | Daily | — | — | 中国药典 2020 【用法与用量】5～10g。 【性味与归经】苦，微寒。归肝、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.
The combination cools the blood and stops bleeding more strongly than either alone, for heat-type intestinal bleeding.
Intestinal wind and toxic accumulation with bright red rectal bleeding; the formula also contains Jing Jie and Zhi Ke.
Core pair of a classical formula — Huai Hua San, Pu Ji Ben Shi Fang (Xu Shuwei)
Together they cool the blood and stop bleeding with a particular focus on the lower burner and Large Intestine.
Bleeding hemorrhoids, bloody stools and bloody dysentery from damp-heat or heat in the blood.
Named pairing — Lü Jingshan, Shi Jinmo Dui Yao
Historical Texts
Shen Nong Ben Cao Jing
Han dynastyRi Hua Zi Ben Cao
Five Dynasties, early 10th centuryChinese Pharmacopoeia (Zhonghua Renmin Gongheguo Yaodian)
Modern, 1995 edition onwardReferences
- He X, Bai Y, Zhao Z, Wang X, Fang J, Huang L, Zeng M, Zhang Q, Zhang Y, Zheng X. Local and traditional uses, phytochemistry, and pharmacology of Sophora japonica L.: A review . Journal of Ethnopharmacology (2016) [DOI]
- Gong Y, Fan L, Wang L, Li J. Flos Sophorae Immaturus: Phytochemistry, bioactivities, and its potential applications . Food Reviews International (2021) [DOI]
- Zuo L, Meng R, Li X, Meng X, Zhang Y, Chen D, Watcharin W. Widely targeted metabolomics study of flower buds of Styphnolobium japonicum from different producing areas . Scientific Reports (2025) [DOI]
- Nguyen HC, Hoang HTT, Miyamoto A, Nguyen TD, Nguyen HTT. Effects of Roasting on Antibacterial and Antioxidant Properties of Sophora japonica Buds—The Involvements of Rutin and Quercetin Constituents . Plants (2024) [DOI]
- Jasuja R, Passam FH, Kennedy DR, Kim SH, van Hessem L, Lin L, Bowley SR, Joshi SS, Dilks JR, Furie B, Furie BC, Flaumenhaft R. Protein disulfide isomerase inhibitors constitute a new class of antithrombotic agents . Journal of Clinical Investigation (2012) [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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