Xiang Ru
StarElsholtzia ciliata (Thunb.) Hyl.
Traditionally used for
- Headaches
- Cough & breathing
- Colds & fever
- Digestion
- Bowel health
- Urinary & fluids
☯ TCM Properties
Induces Sweating and Releases the Exterior; Clears Summer-Heat and Resolves Dampness; Harmonizes the Middle Burner; Promotes Urination and Reduces Edema
Traditional Chinese Uses
Xiang Ru (香薷) is the whole herb of Elsholtzia ciliata (Thunb.) Hyl. and Mosla chinensis Maxim. (Lamiaceae), Herba Elsholtziae seu Moslae. It is acrid and warm and aromatic, entering the Lung and Stomach channels. It induces sweating and releases the Exterior, clears Summer-Heat and resolves Dampness, harmonises the Middle Burner, and promotes urination to reduce oedema.
It is known as "the Ma Huang of summer" (夏月麻黄), and the epithet is precise. Its pattern is the summertime illness caught not from cold weather but from cooling behaviour — eating chilled food and sitting in draughts during hot weather — producing chills and fever without sweating, headache, heaviness, abdominal pain, vomiting and diarrhoea. It heads Xiang Ru San and Xin Jia Xiang Ru Yin for this. Its diuretic action treats acute superficial oedema with difficult urination.
It is a strong diaphoretic and is not used where there is already spontaneous sweating or an exterior deficiency; the tradition specifies that it is taken cool rather than hot, since a hot draught tends to provoke vomiting.
Western Herbalism Properties
Pharmacological Effects
- Antiviral (related species): Crude E. ciliata extracts inhibited Sindbis virus at 0.3 ug/ml with UVA exposure; fluoranthene was the active, minimum active concentration 0.01 ug/ml (Sindbis) and 1.0 ug/ml (murine cytomegalovirus). Data are for E. ciliata, not the official species.
Source: Zhu YP. Chinese Materia Medica: Chemistry, Pharmacology and Applications. Harwood Academic, 1998, p. 59.
Relationships
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Botanical Description
Elsholtzia ciliata (Thunb.) Hyl. (Lamiaceae), known as Vietnamese balm or crested late-summer mint, is a strongly aromatic annual herb native to East Asia and widely naturalized across temperate Eurasia. It grows 30 to 70 cm tall with erect, slender, four-angled, often purplish stems that are sparsely hairy and freely branching. The leaves are opposite, ovate to broadly lanceolate, 3 to 9 cm long, with serrate margins, an acute tip, a wedge-shaped to rounded base and slender petioles; both surfaces bear scattered glandular dots that release a strong mint-like, somewhat lemony scent when rubbed. The inflorescence is a one-sided terminal spike 2 to 7 cm long, dense and comb-like, with conspicuous, broadly ovate, ciliate, often purple-tinged bracts overlapping like the teeth of a comb. The small, two-lipped, pale purple-pink flowers protrude from between the bracts. The aerial parts, harvested in summer when in flower and shade-dried, constitute Xiang Ru in Chinese medicine.
Active Constituents
Dehydroelsholtzia ketone
Furan-containing monoterpene ketoneConcentration: 86.23 percent of the essential oil in the ketone chemotype used in the Lithuanian pharmacological studies
The dominant constituent of the ketone chemotype and, with elsholtzia ketone, the compound that accounts for the cardiac electrophysiological profile of the whole oil. In Langendorff-perfused rabbit hearts it reproduced the effects of the complete essential oil: reduced maximal action potential upstroke velocity, delayed activation and shortened action potential duration, with use-dependence on rapid pacing and docking compatibility with human NaV1.5. This is a class IB-like sodium channel blocking profile.
Elsholtzia ketone
Furan-containing monoterpene ketoneConcentration: 10.64 percent of the essential oil in the same ketone chemotype
The second principal ketone. It shares the sodium-conductance-inhibiting activity of dehydroelsholtzia ketone, and both carry a furan ring, which appears to matter: two unrelated furan compounds, 2-acetylfuran and 5-methylfurfural, were tested for the same reason and also relaxed smooth muscle.
Luteolin-7-O-glucoside
Flavone glycosideIsolated from the aerial parts. It inhibits soluble epoxide hydrolase at micromolar concentrations and suppresses pro-inflammatory cytokines in poly(I:C)-stimulated RAW264.7 macrophages, and separately inhibited coronavirus replication in cell culture. It is the best-characterised of the non-volatile constituents.
Apigenin-7-O-glucoside
Flavone glycosideA second flavone glycoside of the aerial parts with soluble epoxide hydrolase inhibitory activity in vitro and in silico.
Butein-4'-O-glucoside
Chalcone glycosideReported for the first time from this species in 2024. It was the most active of four glycosides tested, downregulating soluble epoxide hydrolase catalytic activity, nitric oxide and prostaglandin E2 production, and the expression of iNOS, COX-2, IL-6 and soluble epoxide hydrolase messenger RNA in stimulated macrophages.
Yuanhuanin
Flavone glycosideAlso reported for the first time from Elsholtzia ciliata in 2024, with soluble epoxide hydrolase inhibitory and cytokine-suppressing activity in the same assay set.
R-Carvone
Monoterpene ketoneA main component of a chemically distinct chemotype of Elsholtzia ciliata essential oil, present alongside DL-limonene rather than the elsholtzia ketones. This matters clinically: the species has at least two chemotypes, and pharmacology reported for one oil does not transfer to the other. In insecticidal assays this chemotype was active in its own right, with a fumigant LC50 for the whole oil of 14.47 mg per litre against Lasioderma serricorne.
DL-Limonene
Monocyclic monoterpeneThe co-dominant constituent of the carvone chemotype, with a fumigant LC50 of 4.42 mg per litre against Lasioderma serricorne, more active than the whole oil.
⚠ Drug Interactions
Class I antiarrhythmics and other sodium channel blockers (lidocaine, mexiletine, flecainide, propafenone, quinidine, and also tricyclic antidepressants and carbamazepine)
The essential oil of this species has a well-characterised class IB-like cardiac profile, established across three independent preparations. In the Langendorff-perfused rabbit heart it widened the QRS and shortened the QT at 0.01-0.1 microlitres per millilitre, with marked effects at 0.3, and concentration-dependently reduced action potential upstroke velocity, amplitude and duration while slowing the spread of electrical activation, the authors identifying preferential inhibition of sodium conductance. In anaesthetised pigs an intravenous bolus prolonged QRS and shortened QT. The two dominant ketones reproduce the effect and dock into human NaV1.5. Adding a prescribed sodium channel blocker to this is straightforwardly additive.
Clinical note: The concentrated oil given intravenously is not the same exposure as a decoction of the herb, and no human data exist at either. Still, avoid the essential oil entirely in anyone on a sodium channel blocking drug, with a wide QRS, with conduction disease, or post-infarct. Treat any report of palpitations or syncope in a patient using an Elsholtzia oil product as potentially drug-related.
Antihypertensives and alpha-1 blockers (doxazosin, tamsulosin, prazosin)
Elsholtzia ciliata essential oil is hypotensive in anaesthetised pigs given an intravenous bolus, and in isolated rat tissue it concentration-dependently reduced phenylephrine-induced contraction of both prostate strips and aortic rings, with an IC50 of 0.24 +/- 0.03 microlitres per millilitre for prostate and 0.72 +/- 0.11 for aorta. The prostate selectivity is the same pharmacology alpha-1 blockers are prescribed for, so the overlap is direct.
Clinical note: Watch for postural symptoms if a patient on an antihypertensive or an alpha blocker starts an Elsholtzia oil preparation. The interaction is inferred from animal and organ-bath work at oil concentrations; a conventional decoction is a much smaller exposure.
Mosla chinensis (the Chinese Pharmacopoeia Xiang Ru, Herba Moslae)
This is a name-versus-binomial problem, not a pharmacological one. The Chinese Pharmacopoeia drug called Xiang Ru is the aerial part of Mosla chinensis Maxim. and its cultivar Jiangxiangru; a review of Elsholtzia ciliata records explicitly that these Mosla materials are used as E. ciliata, and that the sources have also been confused with Elsholtzia splendens. Almost the entire modern pharmacology attributed to Elsholtzia ciliata essential oil comes from one Lithuanian ketone chemotype of the true E. ciliata, a plant also eaten as a food herb, Vietnamese balm or kinh gioi. Neither the cardiac profile nor the flavonoid data can be assumed to hold for a bag of Mosla chinensis dispensed as Xiang Ru, and the batch file's Latin name Herba Elsholtziae seu Moslae acknowledges the ambiguity rather than resolving it.
Clinical note: Establish which plant your Xiang Ru actually is before applying any of the research above. If the material is Mosla chinensis, the sodium-channel and hypotensive findings do not apply to it; if it is authenticated Elsholtzia ciliata, ask which chemotype, since the ketone and carvone oils are chemically different products.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3–10 g | Daily | — | — | 中国药典 2020 【用法与用量】3～10g。 【性味与归经】辛，微温。归肺、胃经。 — 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.
Releasing summer-cold from the exterior combines with transforming dampness and moving qi internally, addressing summertime cold invasion with dampness.
Summer: chills and fever without sweating plus abdominal fullness, nausea or diarrhea.
Core pair of a classical formula — Xiang Ru San, Tai Ping Hui Min He Ji Ju Fang
Evidence Tier
Moderate evidence · 6 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
6
2 verified · 4 unverified
Show 6 studies
- Antiarrhythmic Properties of Elsholtzia ciliata Essential Oil on Electrical Activity of the Isolated Rabbit Heart and Preferential Inhibition of Sodium Conductance
- Evaluation of the Cardiac Electrophysiological and Haemodynamic Effects of Elsholtzia ciliata Essential Oil on Swine
- Elsholtzia ciliata Essential Oil Exhibits a Smooth Muscle Relaxant Effect
- Acute and Sub-Chronic Intraperitoneal Toxicity Studies of the Elsholtzia ciliata Herbal Extract in Balb/c Mice
- Inhibitory Activity of Glycosides from Elsholtzia ciliata against Soluble Epoxide Hydrolase and Cytokines in RAW264.7 Cells
- Luteolin-7-O-glucoside from Elsholtzia ciliata extract inhibits the replication of coronavirus
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
Antiarrhythmic Properties of Elsholtzia ciliata Essential Oil on Electrical Activity of the Isolated Rabbit Heart and Preferential Inhibition of Sodium Conductance
In Langendorff-perfused rabbit hearts studied by surface ECG, microelectrode recording and optical mapping, Elsholtzia ciliata essential oil increased QRS duration and shortened the QT interval at 0.01-0.1 microlitres per millilitre, with markedly stronger effects at 0.3 microlitres per millilitre. It concentration-dependently reduced action potential upstroke velocity, amplitude and duration and slowed the spread of electrical activation, a pattern the authors attribute to preferential inhibition of sodium conductance. This is the foundational cardiac study and the basis of the international patent on the oil as an antiarrhythmic.
Evaluation of the Cardiac Electrophysiological and Haemodynamic Effects of Elsholtzia ciliata Essential Oil on Swine
The whole-animal confirmation. In anaesthetised pigs, an intravenous bolus of the essential oil produced the class IB-like signature seen in the rabbit heart, prolonging QRS and shortening QT, together with effects on arterial blood pressure and heart rate variability, and the kinetic profile of the oil's phytocompounds was determined. Haematological and biochemical parameters were monitored alongside.
Elsholtzia ciliata Essential Oil Exhibits a Smooth Muscle Relaxant Effect
Tension measurements on rat prostate strips and intact aortic rings showed concentration-dependent inhibition of phenylephrine-induced contraction, more pronounced in prostate (IC50 0.24 +/- 0.03 microlitres per millilitre, n = 10) than aorta (0.72 +/- 0.11, n = 4). Chromatography of the oil used gave elsholtzia ketone 10.64 percent and dehydroelsholtzia ketone 86.23 percent. Because both bear a furan ring, the authors also tested 2-acetylfuran and 5-methylfurfural, showing for the first time that these furans relax smooth muscle too.
Acute and Sub-Chronic Intraperitoneal Toxicity Studies of the Elsholtzia ciliata Herbal Extract in Balb/c Mice
The only dedicated toxicity study. Male Balb/c mice received the extract intraperitoneally either as a single 24-hour dose or daily for 60 days. There were no significant adverse effects on haematology, biochemistry, mitochondrial function or the histology of vital organs, and no cytotoxicity to MARC-145, Vero or WBF344 cells in vitro. This is reassuring within its limits: one sex, one species, the intraperitoneal route, and an extract rather than the concentrated oil.
Inhibitory Activity of Glycosides from Elsholtzia ciliata against Soluble Epoxide Hydrolase and Cytokines in RAW264.7 Cells
Four glycosides from the aerial parts of Elsholtzia ciliata were identified as luteolin-7-O-glucoside, yuanhuanin, apigenin-7-O-glucoside and butein-4'-O-glucoside, the second and fourth reported from the species for the first time. All inhibited soluble epoxide hydrolase at micromolar concentrations in vitro and in silico and suppressed pro-inflammatory cytokines in poly(I:C)-stimulated RAW264.7 macrophages. Butein-4'-O-glucoside was the most active, downregulating nitric oxide and prostaglandin E2 production and iNOS, COX-2, IL-6 and soluble epoxide hydrolase expression.
Luteolin-7-O-glucoside from Elsholtzia ciliata extract inhibits the replication of coronavirus
An Elsholtzia ciliata extract and its constituent luteolin-7-O-glucoside inhibited coronavirus replication in cell culture. Cell-culture antiviral activity only, with no animal or human data, and no indication that a decoction achieves the concentrations used.
⚠ Safety & Contraindications
Contraindications
Its use is prohibited in patients with exterior deficiency accompanied by sweating, and summer heat heat syndrome.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, pp. 15–23.
Historical Texts
Ben Cao Gang Mu
Ming dynasty, 1596 CETai Ping Hui Min He Ji Ju Fang
Song dynasty, 1078-1107 CEReferences
- Wang F, Liu X, Chen Y, An Y, Zhao W, Wang L, Tian J, Kong D, Xu Y, Ba Y, Zhou H. Elsholtzia ciliata (Thunb.) Hyland: A Review of Phytochemistry and Pharmacology . Molecules (2022) [DOI]
- Song S, Tang Y, Feng R, Zhang X, An Y, Kong W, Wang J, Zhang J, Liang J. Bioactivities and Synergistic Effect of Elsholtzia ciliata Essential Oil and Its Main Components against Lasioderma serricorne . Molecules (2024) [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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