Xiang Yuan
StarCitrus medica L. / Citrus wilsonii Tanaka
☯ TCM Properties
Courses the Liver and Resolves Constraint; Regulates Qi and Harmonizes the Middle Burner; Dries Dampness and Transforms Phlegm; Regulates Qi and Broadens the Middle Burner
Traditional Chinese Uses
Xiang Yuan (citron fruit) is a warm, aromatic herb used in Chinese medicine to move Liver Qi, harmonize the Stomach, and transform Phlegm. Its primary action on the Liver makes it appropriate for Liver Qi stagnation with chest and hypochondriac distension, depression, and emotional irritability. It also eases digestive discomfort from Qi stagnation including bloating, belching, and nausea, and its Phlegm-transforming action is applied for cough with phlegm from Qi stagnation combined with Phlegm accumulation.
Western Herbalism Properties
Botanical Description
Citrus medica L. (Rutaceae), the citron, is a small, irregularly shaped evergreen tree or shrub 2-5 m tall with stout, angular, often spiny young branches and large, oblong-ovate, leathery leaves bearing translucent oil glands and indistinctly winged petioles. Fragrant, white to purplish-tinged flowers in axillary clusters give rise to large, ovoid to oblong fruits 10-25 cm long with a very thick, bumpy, fragrant yellow rind and sparse, sour or sweet pulp. Closely related cultivars and Citrus wilsonii Tanaka are also accepted sources of the Chinese drug Xiang Yuan. Native to northeast India and adjacent Himalayan foothills and cultivated since antiquity, the dried mature fruit is used in TCM to regulate qi, harmonize the Stomach, and resolve phlegm.
Active Constituents
Limonene
Monoterpene hydrocarbonConcentration: ~54-67% of peel essential oil
The dominant volatile of citron peel oil, responsible for the characteristic aroma. Shows antimicrobial, anti-inflammatory and mild gastroprotective/digestive activity, consistent with the traditional qi-regulating and middle-harmonizing use.
γ-Terpinene
Monoterpene hydrocarbonConcentration: ~7-15% of peel essential oil
A secondary monoterpene of the peel oil with antioxidant and radical-scavenging activity that contributes to the fresh, resinous top-note of the essential oil.
Citral (neral + geranial)
Monoterpene aldehydeConcentration: variable, up to ~12-23% in some peel oils
Lemon-scented aldehyde pair with documented antimicrobial, antifungal and anti-inflammatory effects; a marker of citron flavour quality.
Rutin
Flavonol glycosideConcentration: one of the major peel flavonoids
Antioxidant flavonoid that supports capillary integrity and provides anti-inflammatory activity in the fruit peel.
Neohesperidin
Flavanone glycosideConcentration: major characteristic flavonoid of C. medica
Bitter flavanone glycoside characterising citron; contributes antioxidant activity and is used as a chemotaxonomic quality marker for the fruit.
Hesperidin
Flavanone glycosideConcentration: present in fruit tissue
Vascular-protective and anti-inflammatory citrus flavonoid; supports the traditional use in relieving chest and flank distension.
Citric acid
Organic acidConcentration: abundant in the pulp/juice
The principal organic acid of the acidic citron pulp, contributing to the sour taste and fluid-generating, thirst-relieving quality.
Coumarins / furanocoumarins (e.g. citropten, bergapten)
Coumarin / furanocoumarinConcentration: low (trace) levels in peel
Minor peel constituents; furanocoumarins are the citrus compounds associated with cytochrome-P450 inhibition, though citron contains far lower levels than grapefruit.
⚠ Drug Interactions
CYP3A4-metabolised drugs (e.g. certain statins, calcium-channel blockers, some immunosuppressants)
Citron peel contains coumarins and trace furanocoumarins; furanocoumarins from citrus can irreversibly inhibit intestinal CYP3A4, potentially raising plasma levels of CYP3A4 substrates. Citron's furanocoumarin content is much lower than grapefruit, so clinical relevance is uncertain.
Clinical note: Concentrated citron peel extracts/liqueurs taken with narrow-therapeutic-index CYP3A4 substrates warrant caution; normal culinary use is unlikely to be significant.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3-9g | Daily | — | — | — |
Preparation Methods
Water decoction (tang)
Parts: Dried ripe fruit (sliced)
Typically 3-10 g of dried sliced fruit decocted in water. Being aromatic, it is often added toward the end of cooking to preserve the volatile oils that carry its qi-coursing action.
Powder / added to formulas
Parts: Dried ripe fruit
Dried fruit may be ground and combined with other qi-regulating and phlegm-transforming herbs for Liver-Stomach disharmony with distension, belching and cough with copious phlegm.
Historical Texts
Ben Cao Tu Jing (Illustrated Classic of Materia Medica), Su Song
Northern Song dynasty (1061)Ben Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming dynasty (1596)References
- Venturini N, Barboni T, Curk F, Costa J, Paolini J. Volatile and Flavonoid Composition of the Peel of Citrus medica L. var. Corsican Fruit for Quality Assessment of Its Liqueur . Food Technology and Biotechnology (2014) [DOI]
- Bensky D, Clavey S, Stoger E. Chinese Herbal Medicine: Materia Medica, 3rd Edition (Xiang Yuan / Fructus Citri) . Eastland Press (2004) [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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