Zhi Shi
StarCitrus aurantium L.
☯ TCM Properties
Breaks Qi and Eliminates Focal Distention; Promotes Digestion and Resolves Food Stagnation; Transforms Phlegm and Dissipates Nodules; Purges Heat and Unblocks the Bowels; Lifts Sunken Qi
Traditional Chinese Uses
Zhi Shi (immature bitter orange) is among the most forceful Qi-moving herbs in the Chinese materia medica, capable of powerfully breaking up Qi stagnation and food accumulation in the Stomach and Intestines. It relieves severe bloating, abdominal fullness, chest congestion, and constipation, especially in constitutionally robust patients. Due to its strong downward-draining and dispersing action, it is generally prescribed for short-term use and avoided in those who are weak, pregnant, or elderly.
Western Herbalism Properties
Used In Formulas (6)
Botanical Description
Citrus aurantium (bitter orange, Seville orange) is an evergreen tree in the Rutaceae family, typically reaching 4-10 m in height with a dense, rounded crown and stout, often spiny branches. The leaves are alternate, ovate to elliptic, glossy dark green, 7-10 cm long, with broadly winged petioles. Flowers are white, intensely fragrant, borne singly or in small axillary clusters, with five waxy petals and numerous stamens. The fruit is a hesperidium, 7-8 cm in diameter, with a thick, rough, bitter rind that turns orange at maturity and pulp divided into 10-12 segments containing acidic juice and numerous seeds. Zhi Shi is the dried immature (unripe, green) fruit, harvested in summer before ripening (POWO; PFAF).
Active Constituents
p-Synephrine
Phenethylamine protoalkaloidConcentration: Approx. 0.1-0.5% of dried fruit
The principal adrenergic protoalkaloid of immature bitter orange. It is a selective beta-3 adrenergic agonist with weak affinity for alpha-1 and beta-1/2 receptors, and is associated with mild thermogenic, lipolytic and gastrointestinal prokinetic effects. Unlike ephedrine it does not readily cross the blood-brain barrier, which limits central stimulation at dietary doses.
Naringin
Flavanone-7-O-neohesperidoside (flavonoid glycoside)Concentration: Major flavonoid, roughly 2-5% of dried fruit
A bitter-tasting flavanone glycoside that is one of the marker compounds used to standardise the herb. It shows antioxidant, anti-inflammatory and lipid-lowering activity and contributes to the herb's carminative and digestive actions. Its aglycone naringenin is a documented modulator of intestinal enzymes and transporters.
Hesperidin
Flavanone-7-O-rutinoside (flavonoid glycoside)Concentration: Major flavonoid, approx. 1-4%
A venotonic and anti-inflammatory flavanone glycoside common to Citrus species. It has antioxidant and capillary-stabilising activity and is thought to contribute to the herb's effects on gastrointestinal smooth muscle tone and micro-circulation.
Neohesperidin
Flavanone-7-O-neohesperidoside (flavonoid glycoside)Concentration: Documented, typically <1-2%
A bitter flavanone glycoside used together with naringin as a quality-control marker. It possesses antioxidant activity and, alongside naringin, accounts for much of the intense bitterness that characterises Aurantii Fructus Immaturus.
N-Methyltyramine
Phenethylamine protoalkaloidConcentration: Minor alkaloid, trace to ~0.1%
A sympathomimetic amine that acts as an indirect adrenergic agonist, promoting gastric emptying and gastrointestinal motility. It contributes, with synephrine, to the herb's traditional action of moving stagnant Qi and relieving abdominal distension.
Nobiletin
Polymethoxylated flavoneConcentration: Minor, trace amounts
A lipophilic polymethoxyflavone with well-documented anti-inflammatory, neuroprotective and metabolic activities. It is present at low levels in the immature fruit and adds to the overall antioxidant and gastroprotective profile.
Limonene (essential oil)
Monoterpene (volatile oil)Concentration: Essential oil approx. 0.5-1%; limonene the dominant terpene
The principal volatile constituent of the peel and immature fruit. Limonene-rich essential oil has carminative, spasmolytic and prokinetic actions on the gut and is responsible for much of the aromatic character used traditionally to regulate Qi and disperse fullness.
⚠ Drug Interactions
Caffeine and other stimulants
p-Synephrine and N-methyltyramine are indirect sympathomimetics. When combined with caffeine, multi-ingredient studies have shown additive increases in blood pressure and heart rate, although p-synephrine alone at dietary doses produces minimal cardiovascular change.
Clinical note: Monitor blood pressure and heart rate when combined with caffeine-containing or stimulant weight-loss products, particularly in hypertensive or cardiac patients.
Monoamine oxidase inhibitors (MAOIs)
MAOIs reduce metabolism of sympathomimetic amines such as synephrine and N-methyltyramine, which could potentiate their pressor effect and theoretically precipitate a hypertensive episode.
Clinical note: Avoid concurrent use with MAO inhibitors and for two weeks after their discontinuation.
Sympathomimetic decongestants (e.g. pseudoephedrine, phenylephrine)
Co-administration with other adrenergic agonists may summate cardiovascular and CNS stimulation via overlapping adrenergic mechanisms.
Clinical note: Use caution in patients already taking decongestants or other adrenergic agents.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3-9g | Daily | — | — | — |
Preparation Methods
Water decoction (tang)
Parts: Immature dried fruit
Typically 3-10 g of the sliced immature fruit is decocted in water. Used to break up Qi stagnation, relieve abdominal and epigastric distension, and promote bowel movement, often combined with herbs such as Hou Po and Da Huang.
Dry-fried (chao Zhi Shi)
Parts: Immature dried fruit
The sliced fruit is stir-fried until faintly scorched to moderate its cold, dispersing nature and make it gentler on the Spleen and Stomach, favoured for weaker patients with food stagnation.
Bran-fried (fu chao)
Parts: Immature dried fruit
Stir-frying with wheat bran further tempers the harsh Qi-breaking action and enhances the digestive, Spleen-harmonising effect while reducing the risk of over-purging.
Clinical Studies
Efficacy and Safety of Aurantii Fructus Immaturus Flavonoid Tablets in Patients with Functional Dyspepsia: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Phase III Clinical Trial
A multicenter Phase III trial evaluated flavonoid tablets derived from Aurantii Fructus Immaturus (Zhi Shi) in patients with functional dyspepsia, reporting improvement of core symptoms such as postprandial fullness and early satiety versus placebo over a 4-week course, with a favourable safety profile.
Cardiovascular Safety of Oral p-Synephrine (Bitter Orange) in Healthy Subjects: A Randomized Placebo-Controlled Cross-over Clinical Trial
Healthy adults received oral p-synephrine, the principal alkaloid of bitter orange. No clinically significant changes in heart rate, blood pressure, ECG or blood chemistry were observed relative to placebo, supporting the cardiovascular safety of p-synephrine at the studied dose.
Historical Texts
Shen Nong Ben Cao Jing (Divine Husbandman's Classic of Materia Medica)
Han dynasty (c. 200 CE)Shang Han Lun (Treatise on Cold Damage), Zhang Zhongjing
Eastern Han dynasty (c. 200 CE)References
- Stohs SJ, Preuss HG, Shara M. A Review of the Human Clinical Studies Involving Citrus aurantium (Bitter Orange) Extract and its Primary Protoalkaloid p-Synephrine . International Journal of Medical Sciences 9(7):527-538 (2012) [DOI]
- Stohs SJ. Safety, Efficacy, and Mechanistic Studies Regarding Citrus aurantium (Bitter Orange) Extract and p-Synephrine . Phytotherapy Research 31(10):1463-1474 (2017) [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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