Niu Xi
StarAchyranthes bidentata Blume
Traditionally used for
- Headaches
- Nose & throat
- Urinary & fluids
- Pain & joints
- Heart & circulation
- Energy & fatigue
Cautions & contraindications
- Pregnancy
- Kidney conditions
☯ TCM Properties
Invigorates Blood and Dispels Stasis; Guides Herbs and Blood Downward; Supplements the Liver and Kidneys; Strengthens the Sinews and Bones; Promotes Urination and Relieves Stranguria
Traditional Chinese Uses
Niu Xi (ox-knee root, achyranthes root) is a bitter, sour herb with a strong downward-directing action. It promotes Blood circulation, eliminates stasis, and tonifies the Liver and Kidney — making it valuable for knee and lower back pain, joint stiffness, and muscle weakness from Liver-Kidney deficiency. Its descending nature makes it useful for drawing Fire downward to relieve tooth pain, nosebleeds, and headaches from rising Liver Fire. It also promotes urination and expels Blood stasis from the lower body.
Western Herbalism Properties
Pharmacological Effects
- Protein anabolism: Ecdysterone (oral or i.p.) raised amino acid incorporation in mouse liver fractions within 2-4 h, comparable to 4-chlorotestosterone, and in kidney; 60 days in weaned mice increased body weight and hepatic/renal anabolism.
- Cardiovascular: Ethanolic extract inhibited frog and cat heart; decoction or alcoholic extract i.v. caused transient hypotension in dogs, cats and rabbits with respiratory stimulation and reduced kidney volume in dogs.
- Uterine stimulation: Total saponins 0.125-1.0 mg/ml strongly stimulated isolated rat uterus; local use in rabbits caused contraction within 1-4 min lasting ~25 min, reduced by indomethacin (prostaglandin-mediated).
- Antiinflammatory and analgesic: Alcoholic preparation inhibited formaldehyde paw edema in rats and i.p. suppressed chemically induced writhing.
Source: Zhu YP. Chinese Materia Medica: Chemistry, Pharmacology and Applications. Harwood Academic, 1998, p. 474.
Used In Formulas (43)
Relationships
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Botanical Description
Achyranthes bidentata (Niu Xi, two-toothed amaranth, ox-knee) is a perennial herb in the Amaranthaceae family, growing 70 to 120 centimeters tall, with quadrangular, conspicuously swollen, knee-like nodes (giving rise to both the Chinese common name Niu Xi, ox-knee, and English ox-knee). Stems are erect, sparsely branched, and finely pubescent. Leaves are opposite, elliptic to elliptic-lanceolate, 4 to 12 centimeters long, with entire margins, acuminate tips, and short petioles. The inflorescence is a slender terminal spike 3 to 5 centimeters long that elongates in fruit to 10 to 15 centimeters, bearing numerous small greenish flowers that reflex downward against the rachis as they mature; each flower is subtended by a persistent bract and two stiff bracteoles tipped with sharp barbed spines that cling to clothing and animal fur, aiding dispersal. The medicinal root is long, cylindrical, slightly twisted, 30 to 90 centimeters long and 0.4 to 1 centimeter thick, externally grayish-yellow, internally pale yellowish-brown. Native to East Asia, India, and adjacent regions.
Active Constituents
β-Ecdysterone (20-hydroxyecdysone)
PhytoecdysteroidConcentration: Principal marker; ~0.03-0.1% of dried root, used for pharmacopoeial quality control
The principal quality-control marker of Achyranthis Bidentatae Radix. Exhibits anabolic, protein-synthesis-promoting, osteogenic and neurotrophic activity, and is regarded as a key contributor to the herb's actions on bone, joint and connective tissue.
Inokosterone
PhytoecdysteroidConcentration: Minor ecdysteroid component alongside β-ecdysterone
A co-occurring ecdysteroid contributing to anti-inflammatory, hypotensive and anabolic effects reported for the root.
Oleanolic acid
Pentacyclic triterpenoid (saponin aglycone)Concentration: Released as the aglycone on hydrolysis of the herb's triterpenoid saponins
Aglycone of the herb's triterpenoid saponins; associated with hepatoprotective, anti-inflammatory and lipid-lowering activity.
Achyranthes bidentata triterpenoid saponins (e.g. ginsenoside Ro / bidentatosides)
Oleanane-type triterpenoid saponinsConcentration: Major saponin fraction of the root
Oleanolic-acid glycosides that account for much of the herb's anti-inflammatory, blood-invigorating and uterine-stimulant activity.
Achyranthes bidentata polysaccharides (ABPS)
PolysaccharideConcentration: Abundant water-soluble fraction of the decoction
Immunomodulatory and chondroprotective. Enhance macrophage phagocytosis, NK-cell activity and antibody formation, and have been studied for protection of chondrocyte extracellular matrix in osteoarthritis.
Rubrosterone
Ketosteroid / ecdysteroid derivativeConcentration: Trace steroidal constituent
A minor steroidal constituent reported to have protein-anabolic activity.
Free amino acids and trace elements (e.g. glycine; copper, iron)
Amino acids / mineralsConcentration: Multiple amino acids plus trace metals
Contribute to nutritive tonic effects and are part of the crude drug's overall composition.
⚠ Drug Interactions
Warfarin and other anticoagulant / antiplatelet agents
Niu Xi is a blood-invigorating (huo xue) herb with documented effects on blood circulation and platelet/coagulation parameters; combined use could in theory add to the effect of anticoagulant or antiplatelet drugs.
Clinical note: Monitor for bruising or bleeding when combined with warfarin, heparin, aspirin or clopidogrel; no well-documented clinical case reports exist.
Antidiabetic agents (insulin, sulfonylureas)
Experimental studies report blood-glucose-lowering activity for the crude drug, which could theoretically add to the effect of hypoglycemic medication.
Clinical note: Monitor blood glucose if used alongside antidiabetic therapy.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 5–12 g | Daily | — | — | 中国药典 2020 【用法与用量】5～12g。 【注意】孕妇慎用。 【性味与归经】苦、甘、酸，平。归肝、肾经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Preparation Methods
Decoction
Parts: Root
Typically 5-15 g of dried root simmered in water. Raw (unprepared) Niu Xi is favored to invigorate blood, guide fire and blood downward, and relieve stranguria.
Wine-processed (jiu zhi) decoction
Parts: Root
Root stir-processed with rice wine before decocting to strengthen the tonifying action on the Liver and Kidneys and the effect on sinews and bones.
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
Together they draw blood and ascendant yang downward and anchor rebellious qi, lowering what has surged upward to the head.
Liver yang rising and internal wind with dizziness, headache and flushed face. Avoid in pregnancy.
Core pair of a classical formula — Zhen Gan Xi Feng Tang, Yi Xue Zhong Zhong Can Xi Lu (Zhang Xichun)
Evidence Tier
Limited evidence · 2 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
2
2 verified · 0 unverified
Show 2 studies
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
Compatibility of Achyranthes bidentata components in reducing inflammatory response through Arachidonic acid pathway for treatment of Osteoarthritis
Identified optimal ratios of Achyranthes bidentata-derived components that suppressed the arachidonic-acid inflammatory pathway, supporting the herb's traditional use in osteoarthritis of the knee.
A Systematic Pharmacology and In Vitro Study to Identify the Role of the Active Compounds of Achyranthes bidentata in the Treatment of Osteoarthritis
Used systematic (network) pharmacology plus in vitro experiments to map active compounds of A. bidentata to osteoarthritis-related targets and inflammatory pathways.
⚠ Safety & Contraindications
- Pregnancy
- Kidney conditions
Contraindications
Its use is prohibited in pregnant women or female with profuse menstruation, and cautious in patients with diarrhea due to spleen deficiency or nocturnal emission due to kidney qi insecurity.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, pp. 237–243.
⚠ Rule-Based Cautions
These entries come from the deterministic rule tables that gate Verscienta's formula tools — classical pair prohibitions, pregnancy and lactation contraindications, and dose ceilings.
Pregnancy
Caution descends and moves blood
Historical Texts
Shen Nong Ben Cao Jing (Divine Farmer's Materia Medica)
Eastern Han dynasty (c. 200 CE)Ben Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming dynasty (1578)References
- Chen YR, Niu YS, Zhou HL. Achyranthes bidentata Blume (Amaranthaceae): a review of its botany, traditional uses, phytochemistry, pharmacology, and toxicology . Journal of Pharmacy and Pharmacology (2024) [DOI]
- Li Z, Ma D, Peng L, Li Y, Liao Z, Yu T. Compatibility of Achyranthes bidentata components in reducing inflammatory response through Arachidonic acid pathway for treatment of Osteoarthritis . Bioengineered (2022) [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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