Ma Huang Gen
StarEphedra sinica Stapf
Traditionally used for
- Cough & breathing
☯ TCM Properties
Consolidates the Exterior and Stops Sweating; Astringes the Lungs and secures the surface
Traditional Chinese Uses
Ma Huang Gen (ephedra root) is used in Chinese medicine specifically to stop excessive sweating — a function quite distinct from the aerial parts of the same plant, which promote sweating. It is indicated for both spontaneous daytime sweating (a sign of Qi deficiency) and night sweats (associated with Yin deficiency), and appears in many classical astringent formulas designed to consolidate the Exterior and prevent fluid loss.
Western Herbalism Properties
Pharmacological Effects
- Hypotensive: Root alkaloids are hypotensive. Feruloylhistamine was hypotensive, inhibited histidine decarboxylase and was antihepatotoxic in mice and rats; ephedradine B at 0.1-3 mg/kg i.v. dose-dependently lowered blood pressure in normal and spontaneously hypertensive rats, mainly via ganglion block.
Source: Zhu YP. Chinese Materia Medica: Chemistry, Pharmacology and Applications. Harwood Academic, 1998, p. 661.
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
Ephedra sinica is a low-growing evergreen shrub in the Ephedraceae family, native to arid regions of northern China, Mongolia, and adjacent Russia. It typically reaches 20-40 cm tall, forming dense, mat-like clumps from a woody, branching rootstock. The aerial parts consist of slender, jointed, green, photosynthetic stems with reduced, scale-like opposite leaves at the nodes. The plant is dioecious, producing small cones rather than true flowers; female plants bear fleshy red seed cones in summer. While the aerial stem (Ma Huang) is the famous TCM diaphoretic and stimulant, the root and rhizome (Ma Huang Gen) are harvested separately and are pharmacologically distinct, acting in the opposite direction to inhibit sweating. The root contains macrocyclic spermine alkaloids and ephedroxanes rather than the ephedrine of the stem.
Active Constituents
Ephedrine-type alkaloids (ephedrine, pseudoephedrine, norpseudoephedrine)
Phenylpropylamino (phenylalkylamine) alkaloidConcentration: not a constituent of the root: these alkaloids accumulate in the aerial stems. Measurable ephedrine in a Ma Huang Gen sample indicates contamination with stem material, not correctly identified root
This absence is the defining pharmacological fact about Ma Huang Gen and the reason it behaves as the opposite of the stem. Ephedrine alkaloids are the sympathomimetic, diaphoretic, pressor and legally controlled constituents of Ephedrae Herba. Transcriptomic work localises the biosynthetic machinery for them to the aerial stems, and comparative chemical profiling separates stems from roots on l-norpseudoephedrine, quercetin 4'-O-glucoside and (+)-catechin in the stem versus ephedradine A, epigallocatechin and (-)-epicatechin in the root. A root preparation is therefore not a stimulant and not a decongestant.
Ephedrannin A
A-type proanthocyanidin (dimeric flavonoid)Concentration: a principal phenolic constituent of the root; isolated from Ephedra sinica root material rather than from the stem
Identified as a hypotensive principle of Ephedra root. In LPS-stimulated RAW 264.7 macrophages, ephedrannin A suppressed transcription of TNF-alpha and IL-1beta by blocking NF-kappaB translocation and p38 MAP kinase phosphorylation.
Ephedrannin B
A-type proanthocyanidin (dimeric flavonoid)Concentration: isolated from the roots of Ephedra sinica alongside ephedrannin A
Shares the anti-inflammatory profile of ephedrannin A, suppressing LPS-induced TNF-alpha and IL-1beta through NF-kappaB and p38 MAP kinase in macrophages.
Mahuannin B
Flavonoid dimer (proanthocyanidin-type)Concentration: a root constituent; identified by UPLC-Q/TOF-MS profiling as one of the compounds separating Ephedra Radix from Ephedra Herba
The best-characterised antihidrotic constituent of the root and the compound that explains why root and stem do opposite things to sweating. Mahuannin B inhibits adenylate cyclase, suppressing cAMP production downstream of the beta-2 adrenoceptor, and attenuated hyperhidrosis in mice. Where the stem's ephedrine alkaloids drive sweating, the root's flavonoid dimers block the signalling that produces it.
Mahuannins A, C and D
Flavonoid dimer (proanthocyanidin-type)Concentration: isolated from the roots of Ephedra sinica
Described in the phytochemical literature as hypotensive principles of Ephedra root, part of the same flavonoid-dimer family as mahuannin B and the ephedrannins.
Ephedradines A, B, C and D
Macrocyclic spermine alkaloidConcentration: root-specific alkaloids; ephedradine A is used as a chemical marker distinguishing Ephedra root from Ephedra stem
The alkaloids of Ephedra root are macrocyclic spermine alkaloids, structurally unrelated to the phenylalkylamine ephedrines of the stem, and they possess hypotensive activity in animal models. They are the reason the root's alkaloid fraction lowers rather than raises blood pressure.
Feruloylhistamine
Feruloyl amide of histamineConcentration: isolated from Ephedra root (the crude drug mao-kon)
Reported as a hypotensive principle of Ephedra root; semisynthetic derivatives were subsequently made and tested for the same activity.
Maokonine
L-tyrosine betaineConcentration: isolated from the methanol-soluble extract of the crude drug radix Ephedrae
The one pressor constituent identified in the root, characterised as the hypertensive principle of Ephedra roots. It runs against the root's predominantly hypotensive constituents, so the net blood-pressure effect of a given root preparation depends on the extraction. Note this is a tyrosine betaine, not an ephedrine-type alkaloid, and it does not confer stimulant activity.
Epigallocatechin and (-)-epicatechin
Flavan-3-olConcentration: identified as root-enriched markers in comparative profiling of Ephedra stems and roots
Monomeric flavan-3-ols of the root, the building blocks of the ephedrannin and mahuannin dimers. Their enrichment in the root relative to the stem is used analytically to tell the two parts apart.
⚠ Drug Interactions
Ephedra stem (Ma Huang, Ephedrae Herba) present as a contaminant of the root
Root and stem come off the same plant and are separated by the collector, so stem fragments are the obvious contaminant of root material. Ephedrine alkaloids are localised to the aerial stems; the root's alkaloids are macrocyclic spermines with hypotensive activity. Any measurable ephedrine or pseudoephedrine in a Ma Huang Gen sample is therefore evidence of stem contamination. That matters more here than for most adulteration problems, because the contaminating part is a controlled stimulant: ephedrine alkaloids are the constituents behind the US FDA's 2004 final rule declaring dietary supplements containing them adulterated because they present an unreasonable risk, and ephedrine and pseudoephedrine are regulated methamphetamine precursors in many jurisdictions.
Clinical note: Buy Ma Huang Gen only from suppliers who verify the plant part, and treat any ephedrine or pseudoephedrine peak on a certificate of analysis as adulteration rather than as normal variation. Be aware that regulations and import controls written for 'Ephedra' commonly do not distinguish root from stem, so the root may still be restricted or refused at point of supply even though it is not a source of ephedrine alkaloids; check the rules in your own jurisdiction rather than assuming the part distinction is recognised.
Antihypertensives (ACE inhibitors, beta-blockers, calcium channel blockers, diuretics)
The root is a mixture of opposing cardiovascular principles. Ephedradines A to D, feruloylhistamine, ephedrannin A and mahuannins A and B are described as hypotensive principles of Ephedra root with activity in animal models, while maokonine, an L-tyrosine betaine, was characterised as the root's hypertensive principle. The net effect of a decoction therefore depends on extraction and on the material, and neither direction has been quantified in humans. This is the reverse of the situation with the stem, whose ephedrine alkaloids reliably raise blood pressure and heart rate.
Clinical note: Do not assume Ma Huang Gen is cardiovascularly inert simply because it is not the stimulant part. In a patient on antihypertensives, check blood pressure early in a course. Equally, do not treat it as a pressor risk the way Ma Huang is treated.
Monoamine oxidase inhibitors, sympathomimetic stimulants and decongestants (pseudoephedrine, phenylephrine, amphetamines)
The classic and dangerous MAOI interaction belongs to Ephedrae Herba, not to Ephedrae Radix, because it depends on ephedrine alkaloids, which are stem constituents. A correctly identified root has no such interaction. The entry exists because 'Ephedra' interaction lists are almost always written for the stem and are applied indiscriminately to anything with that name, and because stem contamination would make the stem's interaction real.
Clinical note: Do not withhold Ma Huang Gen from a patient on an MAOI purely because interaction tables list 'Ephedra'. Do confirm the plant part first. If part identity cannot be confirmed, apply the stem's caution.
Beta-2 adrenoceptor agonists (salbutamol, salmeterol, formoterol)
Mahuannin B, an antihidrotic constituent of the root, acts as an adenylate cyclase inhibitor and suppresses beta-2 adrenoceptor/cAMP signalling, which is the same second-messenger pathway beta-2 agonists work through. This was shown in a luciferase reporter system and a mouse hyperhidrosis model, at concentrations and in a tissue context that say nothing directly about airway smooth muscle. No clinical case of reduced bronchodilator effect has been reported.
Clinical note: Not a reason to avoid the herb in an asthmatic. Worth noting only if a patient on a maintenance beta-2 agonist reports reduced control after starting a root-containing formula.
Anticholinergic antihidrotics (glycopyrronium, oxybutynin) and topical aluminium antiperspirants
Ephedra Radix is used specifically to restrain sweating, and mahuannin B attenuated hyperhidrosis in mice by inhibiting adenylate cyclase downstream of the beta-2 adrenoceptor. A rat study of Mulisan decoction, in which Ephedrae Radix et Rhizoma is one of four ingredients, reduced sweat point numbers by 13.5% at the low dose in a reserpine and pilocarpine model. Combining it with a drug that suppresses sweating by a different route is expected to add.
Clinical note: In hot climates or in patients with impaired thermoregulation, be alert to reduced heat tolerance when antihidrotic drugs and this herb are combined. The effect sizes in the animal work are modest.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction, or powder/pills | 3–9 g | Daily | — | — | 中国药典 2020 【用法与用量】3～9g。外用适量，研粉撒扑。 【性味与归经】甘、涩，平。归心、肺经。 — 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.
A herb that specifically stops sweating combined with a heavy astringent mineral that secures the exterior and restrains yin, the pair stops spontaneous and night sweating.
Used with Huang Qi. Not for sweating from an exterior pathogen.
Core pair of a classical formula — Mu Li San, Tai Ping Hui Min He Ji Ju Fang
Evidence Tier
Moderate evidence · 4 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
4
4 verified · 0 unverified
Show 4 studies
- Mahuannin B an adenylate cyclase inhibitor attenuates hyperhidrosis via suppressing β2-adrenoceptor/cAMP signaling pathway
- Antiperspirant effects and mechanism investigation of Mulisan decoction in rats based on plasma metabolomics
- Ephedrannin A and B from roots of Ephedra sinica inhibit lipopolysaccharide-induced inflammatory mediators by suppressing nuclear factor-κB activation in RAW 264.7 macrophages
- Comparative analysis of chemical constituents in the stems and roots of different Ephedra species and their in vitro anti-acute lung injury effects
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
Mahuannin B an adenylate cyclase inhibitor attenuates hyperhidrosis via suppressing β2-adrenoceptor/cAMP signaling pathway
The study set out to explain why Ephedra Herba and Ephedra Radix, from the same plant, do opposite things to sweating. UPLC-Q/TOF-MS profiling with PCA and heat-map analysis separated the two parts, and a beta-2 adrenoceptor luciferase reporter screen plus molecular docking identified flavonoid derivatives in the root as the counterweight to the stem's alkaloids. Mahuannin B emerged as the active antihidrotic, inhibiting cAMP production by suppressing adenylate cyclase activity, and attenuated hyperhidrosis in mice. This is the key mechanistic paper behind the root's antihidrotic identity.
Antiperspirant effects and mechanism investigation of Mulisan decoction in rats based on plasma metabolomics
Mulisan decoction (Ostreae Concha, Astragali Radix, Ephedrae Radix et Rhizoma and Tritici Levis Fructus at 6:6:6:5) was tested in 50 male Sprague-Dawley rats given intraperitoneal reserpine 0.5 mg/kg daily for 10 days, with pilocarpine 25 mg/kg used to provoke sweating. The low-dose group showed a significant 13.5% reduction in sweat point numbers versus the untreated model group, with improved body weight and immune balance markers. Ma Huang Gen is one of four ingredients, so the result supports the formula rather than isolating the herb.
Ephedrannin A and B from roots of Ephedra sinica inhibit lipopolysaccharide-induced inflammatory mediators by suppressing nuclear factor-κB activation in RAW 264.7 macrophages
Ephedrannin A and B, A-type proanthocyanidins isolated specifically from Ephedra sinica roots, suppressed transcription of TNF-alpha and IL-1beta in LPS-stimulated RAW 264.7 macrophages. PCR, ELISA, electrophoretic mobility shift assay and immunocytochemistry showed the effect ran through suppression of NF-kappaB translocation and p38 MAP kinase phosphorylation. The compounds tested are root constituents, not stem constituents.
Comparative analysis of chemical constituents in the stems and roots of different Ephedra species and their in vitro anti-acute lung injury effects
Chromatography and mass spectrometry identified 27 constituents in Ephedra stems and 35 in Ephedra roots across several species. Quercetin 4'-O-glucoside, (+)-catechin and l-norpseudoephedrine were prominent markers of the stem, while ephedradine A, epigallocatechin and (-)-epicatechin marked the root; anti-inflammatory potency in an LPS-stimulated in vitro acute lung injury model differed between species, and network pharmacology pointed to 14 core components acting on MAPK/NF-kappaB targets. Directly useful for telling correctly identified Ma Huang Gen from stem-contaminated material.
⚠ Safety & Contraindications
Contraindications
Its use is prohibited in patients with exterior pathogen.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, pp. 383–384.
Historical Texts
Shen Nong Ben Cao Jing
Han dynasty, compiled by the 2nd century CEBen Cao Jing Ji Zhu
Southern Dynasties (Liang), around 500 CE, compiled by Tao HongjingBen Cao Gang Mu
Ming dynasty, 1596References
- Mitsuru Tamada, Katsuya Endo, Hiroshi Hikino. Maokonine, Hypertensive Principle of Ephedra Roots . Planta Medica (1978) [DOI]
- Daphne E. González-Juárez, Abraham Escobedo-Moratilla, Joel Flores, Sergio Hidalgo-Figueroa, Natalia Martínez-Taguéña, Jesús Morales-Jiménez, Alethia Muñiz-Ramírez, Guillermo Pastor-Palacios, Sandra Pérez-Miranda, Alfredo Ramírez-Hernández, Joyce Trujillo, Elihú Bautista. A Review of the Ephedra genus: Distribution, Ecology, Ethnobotany, Phytochemistry and Pharmacological Properties . Molecules (2020) [DOI]
- Taketo Okada, Hironobu Takahashi, Yutaka Suzuki, Sumio Sugano, Masaaki Noji, Hiromichi Kenmoku, Masao Toyota, Shigehiko Kanaya, Nobuo Kawahara, Yoshinori Asakawa, Setsuko Sekita. Comparative analysis of transcriptomes in aerial stems and roots of Ephedra sinica based on high-throughput mRNA sequencing . Genomics Data (2016) [DOI]
- Songyuan Tang, Junling Ren, Ling Kong, Guangli Yan, Chang Liu, Ying Han, Hui Sun, Xi-Jun Wang. Ephedrae Herba: A Review of Its Phytochemistry, Pharmacology, Clinical Application, and Alkaloid Toxicity . Molecules (2023) [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 Ma Huang Gen.
No notes yet.