Chou Wu Tong
StarClerodendrum trichotomum
Synonyms: Clerodendrum trichotomum var. ferrugineum, Clerodendrum fargesii, Siphonanthus trichotomus, Siphonanthus trichotomus var. ferrugineus, Siphonanthus yakusimensis, Clerodendrum trichotomum var. yakusimense, Clerodendrum trichotomum f. ferrugineum, Clerodendrum trichotomum var. tomentosum, Clerodendrum koshunense, Clerodendrum serotinum, Siphonanthus trichotomus var. esculentus, Siphonanthus trichotomus var. fargesii, Clerodendrum trichotomum var. villosum, Clerodendrum trichotomum f. albicarpum, Clerodendrum trichotomum var. fargesii, Clerodendrum yakusimense, Ovieda trichotoma, Clerodendrum trichotomum var. esculentum
Traditionally used for
- Headaches
- Dizziness
- Ears & hearing
- Nerves & recovery
- Pain & joints
- Blood pressure
Cautions & contraindications
- Heart conditions
☯ TCM Properties
Dispels Wind-Dampness; Calms Liver Yang and lowers Blood pressure
Traditional Chinese Uses
Chou Wu Tong (臭梧桐) is the leaf and young twig of Clerodendrum trichotomum Thunb. (Lamiaceae), Folium Clerodendri — the name, "stinking parasol tree", records the unpleasant smell of the fresh leaf. It is acrid, bitter and sweet and cool, entering the Liver channel. It dispels Wind-Dampness, and calms Liver Yang and lowers blood pressure.
It is used for Wind-Damp painful obstruction with aching, swollen joints, numbness of the limbs and lower back and knee pain, and for hemiplegia following windstroke. Its second and now more prominent use is ascendant Liver Yang with hypertension, headache, dizziness and tinnitus, where it is classically paired with Xi Xian Cao — the two together forming the traditional pairing for raised blood pressure.
The leaf is held to be most effective gathered before the plant flowers, and prolonged high heat in preparation is said to weaken its blood-pressure-lowering action.
Western Herbalism Properties
Pharmacological Effects
- Analgesic and antiinflammatory: Analgesic in mice (tail electrical stimulation); i.p. clerodendronin B 400-800 mg/kg outperformed morphine 10-20 mg/kg. Antiinflammatory only in combination with Xi Xian Cao or Gui Zhen Cao, none active alone.
- Sedative: Sedative and prolonged pentobarbital anesthesia without hypnotic or anticonvulsant action; clerodendronin A had a sedative index greater than reserpine.
- Hypotensive: Consistent in acute and chronic animal studies; oral hot-water extract lowered BP 16-57% in renal hypertensive rats; i.v. gave biphasic fall in dogs/rats. Mechanism mainly vasomotor-center inhibition and baroreceptor reflex, minor ganglionic block.
Source: Zhu YP. Chinese Materia Medica: Chemistry, Pharmacology and Applications. Harwood Academic, 1998, p. 267.
Relationships
Full-screen graph →Click a node for details · double-click to expand it · Ctrl/⌘ + scroll or two fingers to zoom and pan.
Gallery
Botanical Description
Clerodendrum trichotomum is a large deciduous shrub or small tree reaching 3-6 m tall, with a spreading habit. Leaves are broadly ovate, 8-20 cm long, opposite, with an unpleasant odor when crushed (giving rise to the Chinese name meaning "stinking parasol tree"). Fragrant, white tubular flowers are borne in lax terminal cymes in late summer. Each flower has a prominent, inflated, reddish-pink calyx that persists and enlarges in fruit. The fleshy, bright blue-turquoise berries (4-8 mm) are nestled within the star-shaped red calyx, creating a striking ornamental display.
Hillsides, thickets, forest margins, and roadsides; native to China, Japan, and Korea, widely cultivated as an ornamental shrub in temperate regions worldwide.
Clerodendrum trichotomum is common throughout its native range in East Asia and is widely cultivated as an ornamental. It has naturalized in some areas of North America. No conservation concerns.
Active Constituents
Acteoside (verbascoside)
Phenylethanoid (phenylpropanoid) glycosideConcentration: Phenylpropanoids make up about 4.6 per cent of the bark and about 0.6 per cent of the leaves
The dominant phenolic of the plant and the compound most often credited with its hypotensive reputation, inhibiting angiotensin converting enzyme in vitro with an IC50 of 373.3 micrograms per millilitre. It was also identified by HPLC as the active antiviral component of the leaf extract against respiratory syncytial virus in cell culture and in mice.
Isoacteoside
Phenylethanoid (phenylpropanoid) glycosideConcentration: Isolated from the stem alongside acteoside in bioassay-guided fractionation
An acteoside positional isomer with essentially the same angiotensin converting enzyme inhibition, IC50 376.0 micrograms per millilitre. It is one of five phenylpropanoid glycosides isolated by activity-guided fractionation of the stem extract.
Leucosceptoside A
Phenylethanoid (phenylpropanoid) glycosideConcentration: Isolated from the ethyl acetate soluble stem extract
Inhibits angiotensin converting enzyme in vitro with an IC50 of 423.7 micrograms per millilitre, in the same weak range as the other glycosides of the group.
Martynoside
Phenylethanoid (phenylpropanoid) glycosideConcentration: Isolated from the ethyl acetate soluble stem extract
The least potent of the five phenylpropanoid glycosides tested for angiotensin converting enzyme inhibition, IC50 524.4 micrograms per millilitre; its isomer isomartynoside gave 505.9 micrograms per millilitre.
Trichotomoside
Phenylethanoid (phenylpropanoid) glycosideA phenylpropanoid glycoside described from this species and named after it, isolated and characterised as an antioxidant. It has no cardiovascular data of its own.
Clerodendronin B
Crystalline acid-soluble leaf principle of undetermined structural classConcentration: Isolated as granular crystals from the leaves and twigs; 1 gram corresponds to roughly 170 grams of crude drug on the reported equivalence
Given intraperitoneally to mice at 400 to 800 mg/kg it produced hot-plate analgesia reported as stronger and longer-lasting than morphine at 10 to 20 mg/kg, with an intraperitoneal LD50 of 3.21 g/kg. Its companion clerodendronin A has an intraperitoneal LD50 of 1.84 g/kg. These are 1960 Chinese isolations whose structures were never fully settled, and the doses are parenteral and enormous relative to any oral use.
Clerodendrin A
Neoclerodane diterpeneConcentration: Isolated from the leaves by hexane-acetone extraction
One of a series of neoclerodane diterpenes, clerodendrins A, B and D through H, described from the leaves by Japanese workers. They are best known as insect feeding and oviposition stimulants for Athalia sawflies rather than for any mammalian pharmacology, and they are not the compounds behind the blood pressure effect.
Trichotomine
Bis-indole alkaloidConcentration: Isolated from the ethanol extract of the fruits
The blue pigment of the ripe fruit, isolated with its congener trichotomine G1. It is a fruit constituent and does not belong to the leaf and twig drug used as Chou Wu Tong.
⚠ Drug Interactions
Antihypertensive drugs (ACE inhibitors, angiotensin receptor blockers, calcium channel blockers, beta-blockers)
The hypotensive effect of the leaf and twig water extract is one of the better-replicated findings in the Chinese pharmacology of the 1950s and 1960s: it lowered blood pressure in anaesthetised and conscious rats and dogs and in renal hypertensive rats and dogs, by oral and by parenteral routes. The mechanism has been attributed variously to central and vascular receptor effects, to direct vasodilatation with ganglionic blockade, and to increased renal blood flow with natriuresis. The candidate molecular explanation is angiotensin converting enzyme inhibition by the phenylpropanoid glycosides, but the measured IC50 values sit between 373 and 524 micrograms per millilitre, which is far too weak to be reached in plasma, so the animal effect is probably not mediated that way and the true mechanism is unsettled.
Clinical note: The herb is used in China precisely for hypertension, so a treated hypertensive patient is exactly who will be taking it. Check blood pressure at the start of treatment and after any dose change, and warn about postural symptoms. There are no human trials, so do not adjust conventional antihypertensives in anticipation of an effect.
Diuretics
Extracts given to rats at 0.1 and 0.5 g/kg and to dogs at 0.24 g/kg lowered blood pressure by increasing renal blood flow and promoting urinary water and sodium excretion. Adding that to a loop or thiazide diuretic would be expected to compound both the volume loss and the sodium loss.
Clinical note: Watch for dehydration, postural dizziness and low sodium in older patients on a diuretic, particularly in hot weather.
Alpha-blockers, nitrates and phosphodiesterase type 5 inhibitors
Part of the antihypertensive action reported in dogs, rabbits, cats and rats at 0.5 to 1 g/kg was attributed to direct vasodilatation together with blockade of autonomic ganglia. Ganglionic blockade abolishes the reflex vasoconstriction that defends standing blood pressure, so it stacks badly with any drug that also causes vasodilatation or blunts the reflex.
Clinical note: Advise rising slowly. Be cautious in men taking an alpha-blocker for prostatic symptoms and in anyone on a nitrate.
Dichroa febrifuga (Chang Shan, and its leaf Shu Qi)
This species carries the Chinese name Haizhou Changshan precisely because material from the Haizhou area of Lianyungang was once dispensed as Changshan, and Su Song described it in the Ben Cao Tu Jing under the head entry for Shu Qi, the sprout of Changshan. Changshan is Dichroa febrifuga, whose febrifugine alkaloids are powerfully emetic and have a narrow margin between antimalarial and toxic dose. The two drugs share nothing pharmacologically; the confusion is one of name and provenance, and it is baked into the classical record rather than being a modern market problem.
Clinical note: Confirm you have been supplied Clerodendrum leaf and twig and not Dichroa. Severe vomiting after a dose intended as Chou Wu Tong should raise immediate suspicion of Changshan substitution.
Sedatives, hypnotics and other central nervous system depressants
Sedative activity of the decoction is a consistent finding in the same body of mid-century Chinese animal work that produced the hypotensive and analgesic data, and both recent reviews list sedation among the reproducible effects. No target has been identified and no human data exist.
Clinical note: Mention possible drowsiness, especially alongside a benzodiazepine, a Z-drug or a sedating antihistamine.
Analgesics and opioids
Intraperitoneal decoction above 1.65 g/kg produced measurable analgesia in mice, peaking 20 to 40 minutes after dosing and lasting about two hours, and the isolated principle clerodendronin B outperformed morphine in the hot-plate test at the doses used. Nothing is known about the receptor involved, and nothing about oral human exposure, so this is a plausibility rather than a documented interaction.
Clinical note: No action required. If a patient reports unexpectedly good pain control after adding the herb to an opioid, review the opioid dose rather than assuming tolerance has changed.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 4.5–15 g | daily | — | adult | Bensky, Clavey & Stöger, Chinese Herbal Medicine: Materia Medica, 3rd ed. (2004): 4.5–15 g. Add later when treating hypertension to preserve antihypertensive effect. |
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
The pair dispels wind-damp and unblocks the channels, relieving joint pain and numbness; it is also used to calm hyperactive liver yang.
Wind-damp painful obstruction with aching and weak lower limbs.
Core pair of a classical formula — Xi Tong Wan, Ji Yan Liang Fang Ba Cui
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
3 verified · 2 unverified
Show 5 studies
- Angiotensin converting enzyme inhibitory phenylpropanoid glycosides from Clerodendron trichotomum
- Anti-Respiratory Syncytial Virus Activity of Plantago asiatica and Clerodendrum trichotomum Extracts In Vitro and In Vivo
- Trichotomoside: A New Antioxidative Phenylpropanoid Glycoside from Clerodendron trichotomum
- Antioxidant Activity of Jionoside D from Clerodendron trichotomum
- Two novel polyketones from the leaves and twigs of Clerodendrum trichotomum
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
Angiotensin converting enzyme inhibitory phenylpropanoid glycosides from Clerodendron trichotomum
Bioassay-guided fractionation of the ethyl acetate soluble stem extract yielded acteoside, leucosceptoside A, martynoside, an acteoside isomer and isomartynoside. All five inhibited angiotensin converting enzyme dose-dependently, with IC50 values of 373, 423, 524, 376 and 505 micrograms per millilitre respectively. The authors propose this as at least part of the antihypertensive mechanism. The caveat a practitioner needs is that these are microgram-per-millilitre potencies, orders of magnitude weaker than a pharmaceutical ACE inhibitor, and are unlikely to be reached in plasma from an oral decoction.
Anti-Respiratory Syncytial Virus Activity of Plantago asiatica and Clerodendrum trichotomum Extracts In Vitro and In Vivo
Non-cytotoxic concentrations of the extract reduced respiratory syncytial virus replication, virus-induced cell death, viral transcription and protein synthesis and syncytium formation in HEp2 and A549 cells, and oral dosing improved viral clearance from the lungs of BALB/c mice. HPLC identified acteoside as the active component of both herb extracts, and purified acteoside reproduced the effect in vitro and in vivo. Combined in vitro and animal work; there is no human antiviral data.
Trichotomoside: A New Antioxidative Phenylpropanoid Glycoside from Clerodendron trichotomum
Isolation and structure elucidation of a new phenylpropanoid glycoside from the plant, characterised as an antioxidant. It documents the chemistry rather than any therapeutic effect.
Antioxidant Activity of Jionoside D from Clerodendron trichotomum
Jionoside D isolated from the plant showed antioxidant activity in cell-free and cellular assays. One of a series of Korean papers establishing the phenylpropanoid glycoside fraction as the antioxidant principle of the leaf.
Two novel polyketones from the leaves and twigs of Clerodendrum trichotomum
Clerodendruketones A and B were isolated from the leaves and twigs, the part used as Chou Wu Tong, alongside four known compounds. Both new polyketones showed antibacterial activity against Escherichia coli and Staphylococcus aureus by turbidimetry, and one ecdysanol showed moderate DPPH radical scavenging. Chemistry paper on the correct plant part.
⚠ Safety & Contraindications
- Heart conditions
Contraindications
When using for high blood pressure, it should not be decocted for a long time.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, pp. 117–121.
Side Effects
- Rats given 0.25 and 2.5 g/kg extract orally for 60 days showed no abnormalities apart from increased water intake and watery stool in a few
- Dogs: 10 g/kg decoction orally had no effect on liver, blood or ECG; 20 g/kg caused vomiting
Source: Zhu YP. Chinese Materia Medica: Chemistry, Pharmacology and Applications. Harwood Academic, 1998, p. 267.
Historical Texts
Ben Cao Tu Jing (Illustrated Classic of the Materia Medica), Su Song
Northern Song dynasty, 1061 CEBen Cao Gang Mu Shi Yi (Supplement to the Compendium of Materia Medica), Zhao Xuemin
Qing dynasty, 1765Zhong Hua Ben Cao (Chinese Materia Medica)
Modern, 1999Chinese pharmacological reports on Chou Wu Tong, Xu and colleagues
Modern, 1957 to 1962References
- Li L; Tang Z; Xiao S; Dai X; Wang Y; Wei X. Clerodendrum trichotomum Thunb.: a review on phytochemical composition and pharmacological activities . Frontiers in Pharmacology (2025) [DOI]
- Gomulski J; Grzegorczyk-Karolak I. Clerodendrum trichotomum Thunberg—An Ornamental Shrub with Medical Properties . Molecules (2024) [DOI]
- Wang JH; Luan F; He XD; Wang Y; Li MX. Traditional uses and pharmacological properties of Clerodendrum phytochemicals . Journal of Traditional and Complementary Medicine (2018) [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 Chou Wu Tong.
No notes yet.