Qing Pi
StarCitrus reticulata Blanco
☯ TCM Properties
Soothes the Liver and Regulates Qi; Resolves Phlegm and Disperses Accumulation; Promotes Digestion and Resolves Food Stagnation; Dries Dampness and Transforms Phlegm
Traditional Chinese Uses
Qing Pi (unripe tangerine peel) is a warm, acrid herb that strongly moves Liver Qi, breaks up accumulations, and reduces food stagnation. It is significantly more aggressive than the mature Chen Pi, and is used when Liver Qi stagnation is substantial — causing flank pain, hypochondriac distension, and hernial pain — or when food stagnation with abdominal pain requires forceful dispersal. Its downward-directing, dispersing action also treats masses from Qi and food accumulation. It is used cautiously in those who are deficient or pregnant.
Western Herbalism Properties
Botanical Description
Citrus reticulata Blanco (Rutaceae), the mandarin orange, is a small evergreen tree or large shrub 2-8 m tall with slender often spiny branches, ovate to elliptic single-foliolate leaves with narrowly winged petioles, and fragrant white star-shaped flowers. The depressed-globose fruit has a loose easily-peeled aromatic orange rind and sweet juicy segments. For Qing Pi, the immature green pericarp is collected in summer from young fruits that have dropped or are thinned from the tree, sun-dried, and either left whole or cut into pieces. In TCM, Qing Pi is bitter and acrid in flavor and warm in nature, entering the Liver, Gallbladder, and Stomach channels; it spreads Liver qi, breaks up qi stagnation, dissipates clumps, and reduces food stagnation. The mature peel (Chen Pi) is a separate medicinal.
Active Constituents
Hesperidin
Flavanone glycosideConcentration: Dominant flavonoid; ~160.8 mg/g reported in Citri Reticulatae Pericarpium Viride (far above the 5% Pharmacopoeia minimum)
The principal quality marker of the herb, with documented antioxidant, anti-inflammatory and vascular-protective (capillary-strengthening) activity. Contributes to the qi-regulating and hepatoprotective reputation of the peel.
Synephrine (p-synephrine)
Protoalkaloid (phenethylamine)Concentration: ~5.6 mg/g; higher in the immature green peel than in mature Chen Pi
A weak adrenergic (mainly beta-3/alpha) agonist that raises smooth-muscle tone and can mildly increase blood pressure and metabolic rate. Underlies part of the herb's stronger, more descending qi-moving action compared with mature peel, and is the main constituent of concern for stimulant/cardiovascular interactions.
Nobiletin
Polymethoxylated flavoneConcentration: ~4.3 mg/g
Lipophilic flavone with anti-inflammatory, lipid-lowering and neuroprotective activity in preclinical models; inhibits several cytochrome-P450 and NF-kB pathways.
Tangeretin
Polymethoxylated flavoneConcentration: ~3.1 mg/g
Anti-inflammatory and antiproliferative polymethoxyflavone; modulates CYP enzymes and P-glycoprotein, contributing to potential herb-drug interactions.
Limonin
Limonoid (triterpenoid)Concentration: ~4.1 mg/g
Bitter limonoid with reported anti-inflammatory and digestive-stimulant effects; part of the bitter principle that supports the herb's action on food stagnation.
D-Limonene
Monoterpene (volatile oil)Concentration: ~23% of the essential oil
Major aromatic constituent; carminative and prokinetic, relaxing gastrointestinal smooth muscle and supporting the qi-regulating, digestive functions of the peel.
gamma-Terpinene
Monoterpene (volatile oil)Concentration: ~33% of the essential oil
Predominant volatile monoterpene with antioxidant and antimicrobial activity; contributes to the aromatic, dispersing quality of the fresh green peel.
Narirutin / Naringin
Flavanone glycosidesConcentration: Minor to moderate flavanone glycosides
Antioxidant flavanones that add to the total flavonoid load; naringin is a known modulator of intestinal drug transporters and CYP3A4.
⚠ Drug Interactions
Monoamine oxidase inhibitors (MAOIs) and sympathomimetic stimulants
The p-synephrine in the green peel is an adrenergic agonist. Co-administration with MAOIs, decongestants, or other stimulants could theoretically potentiate blood-pressure elevation, tachycardia and palpitations.
Clinical note: Use cautiously in patients on MAOIs or stimulant medications, and in those with hypertension or arrhythmia; monitor blood pressure and heart rate.
CYP3A4 / P-glycoprotein substrates (e.g. statins, calcium-channel blockers, ciclosporin)
Citrus flavonoids (naringin, nobiletin, tangeretin) and furanocoumarins can inhibit intestinal CYP3A4 and P-glycoprotein, a mechanism analogous to the grapefruit effect, potentially raising plasma levels of affected drugs.
Clinical note: Mandarin peel carries a lower furanocoumarin burden than grapefruit, but caution is warranted with narrow-therapeutic-index CYP3A4 substrates; separate dosing and monitor for enhanced drug effect.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3-9g | Daily | — | — | — |
Preparation Methods
Water decoction
Parts: Immature (green) pericarp
Typically 3-10 g decocted in water. Because the qi-moving action is strong and descending, it is added toward the end of cooking to preserve the aromatic volatile oil. Often stir-fried (chao) or vinegar-processed (cu zhi) to soften its dispersing nature and focus the action on the Liver.
Vinegar-processed (cu Qing Pi)
Parts: Immature (green) pericarp
Slices are stir-fried with rice vinegar to guide the herb to the Liver channel and enhance its pain-relieving, Liver-soothing effect for hypochondriac and breast distension. Used in decoctions and pills at 3-9 g.
Powder or pill
Parts: Immature (green) pericarp
Dried peel is powdered and incorporated into formula pills or capsules for qi stagnation and food accumulation. Because of its strong qi-dispersing action, it is used cautiously and in reduced amounts in patients with qi deficiency or profuse sweating.
Clinical Studies
Identification of volatile and nonvolatile compounds in Citri Reticulatae Pericarpium Viride using GC-MS, UPLC-Q-Exactive Orbitrap-MS, and HPLC-PDA
Combined GC-MS, UPLC-Orbitrap-MS and HPLC-PDA profiling of the green peel identified 56 volatile and 42 non-volatile compounds and quantified hesperidin (~160.8 mg/g), synephrine, nobiletin, tangeretin and limonin, providing the constituent basis for the herb's activity.
Systems Pharmacology Study of the Anti-Liver Injury Mechanism of Citri Reticulatae Pericarpium
Network-pharmacology analysis of the closely related tangerine peel (the mature congener of Qing Pi) mapped 25 active flavonoids to hepatoprotective targets, supporting anti-inflammatory and anti-liver-injury actions that align with the herb's Liver-soothing indication.
Historical Texts
Zhen Zhu Nang (Pouch of Pearls)
Jin dynasty (12th-13th c.), attributed to Zhang YuansuBen Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming dynasty, 1578References
- Li J, Zou S, Yang W, Peng M, Chen B, Deng J, Wei M, Zheng G. Identification of volatile and nonvolatile compounds in Citri Reticulatae Pericarpium Viride using GC-MS, UPLC-Q-Exactive Orbitrap-MS, and HPLC-PDA . Food Science & Nutrition (2023) [DOI]
- Zhang F, et al.. Systems Pharmacology Study of the Anti-Liver Injury Mechanism of Citri Reticulatae Pericarpium . Frontiers in Pharmacology (2021) [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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