What Is Qing Pi
Qing Pi commonly known as Citri Reticulatae Pericarpium Viride or Green Tangerine Peel is the small young fruit or the immature pericarp of Citrus reticulata Blanco and its cultivars, which is a small evergreen tree belonging to the family Rutaceae. The first one is also called Ge Qing Pi, while the other one is called Si Hua Qing Pi. It is a relatively practical Chinese herbal medicine, which first appeared in <Tu Jing Ben Cao> (Illustrated Classic of Materia Medica) in 1,061 AD.
Citrus reticulata Blanco also known as Mandarin orange is a common fruit tree. In 2021, approximately 6.82 million hectares of land were used to cultivate 98 million tons of citrus worldwide. Their fruit is one of the most produced and consumed fruits in the world. They have a high economic value and can be made into beverages, canned goods, cosmetics, medicines, and additives.
From May to June, people gather the young fruits that fall naturally from Citrus reticulata Blanco and its cultivars, dry them in the sun, cut them into thick slices, and make them into Ge Qing Pi. From July to August, people gather their immature fruits, cut their peel into four pieces, remove their flesh pieces, dry them in the sun, cut them into shreds, use them directly, or stir-fry them with vinegar, and make them into Chinese herbal medicines.
Qing Pi and Chen Pi come from the same origin, and they contain similar chemical components. Qing Pi contains tectorigenin, nobiletin, sinensetin, apigenin, dihydroxy-trimethoxyflavone, tangeretin, isoquercitroside, troxerutin, isosinensetin, isoschaftoside, myricetin, kaempferol-3-O-rutinoside, luteolin-7-O-rutinoside, rhoifolin, tricin, dihydromyricetin, eriocitrin, astilbin, hesperidin, narirutin, naringin, poncirin, neohesperidin, theaflavin, curcumin, synephrine, N-methyltyramine, acrimarine, buntanine, junosine, 5-methoxynoracronycine, limonene, γ-terpinene, β-myrcene, α-pinene, β-pinene, α-terpineol, camphene, terpinolene, 3-carene, spathulenol, trans-nerolidol, aromadendrene, elemol, valencene, obacunone, nomilin, caffeic acid, gallic acid, vanillic acid, ferulic acid, cinnamic acid, limonin, deacetylnomilin, polysaccharides, thymol, β-sitosterol, and some trace elements.
Generally, the black-green and solid Qing Pi with a strong fragrance is preferred. Si Hua Qing Pi with black-green outer skin, yellow-white inner surface, and a strong fragrance is preferred.
According to the Chinese Pharmacopoeia, the medicinal nature of Qing Pi is relatively warm, with a bitter and pungent taste. It has a certain therapeutic effect on the pathological changes of the liver, gallbladder, and gastric meridians.
In traditional Chinese medicine, it is often used to soothe the liver and relieve stagnant qi, remove food retention, and treat distending pain in the hypochondrium, distending pain in the breast, udder caking, acute mastitis, dysmenorrhea, periumbilical colic due to cold, dyspepsia, abdominal distention and pain, abdominal mass, cholelithiasis, chronic cholecystitis, paroxysmal supraventricular tachycardia, tuberculous lymphadenitis, and shock.
There are about 200 kinds of traditional Chinese medicine prescriptions containing it, such as Tian Tai Wu Yao San, San Pi Tang, and Qing Pi Wan.
- Anti-inflammation, decreased the expression of NO, PGE2, tumor necrosis factor-α, and interleukin-6 in LPS-induced RAW264.7 cells .
- Anti-oxidation, scavenging DPPH, ABTS, and hydroxyl radicals .
- Soothing the liver and regulating qi, treating distending pain in the hypochondrium, distending pain in the breast, udder caking, or periumbilical colic due to cold caused by liver depression and qi stagnation.
- Removing food retention, and treating abdominal distension and pain caused by retention of food leading to stagnation of qi.
- Relieving stagnant qi and resolving masses, treating abdominal mass caused by qi stagnation leads to blood stagnation or chronic malaria.
- Tangeretin may inhibit the expression of interleukin-23 and other related proteins via the Notch signaling pathway, thereby treating acute lung injury .
- Hesperidin inhibited collagen-, arachidonic acid (AA)-, ADP-, and thrombin-induced rat platelet aggregation in vitro and ex vivo .
- Hesperidin has an inhibitory effect against the development of neurodegenerative diseases such as Parkinson’s, Alzheimer’s, Huntington’s diseases, and multiple sclerosis .
- It contains polymethoxyflavones that improve metabolic disorders like hyperlipidemia by modulating the gut microbiome and amino acid metabolism [6, 7].
- Its alkaloid fraction and synephrine protected Guinea pigs against histamine-induced experimental asthma in a dose-dependent manner .
- Its flavonoid extracts decreased the viability of HCT-116, HT-29, CT-26, MCF-7, and HepG2 cancer cells . In addition, its extract induced apoptosis in the human colon cancer cell line SNU-C4 .
- It can be used in combination with Chai Hu (Radix Bupleuri), Yu Jin (Turmeric Tuber), Xiang Fu (Rhizoma Cyperi), etc. to treat distending pain in the hypochondrium, distending pain in the breast caused by liver depression and qi stagnation.
- It can be used in combination with Chai Hu (Radix Bupleuri), Ju Ye (Folium Citri Reticulatae), etc. to treat udder caking.
- It can be used in combination with Wu Yao (Radix Linderae), Xiao Hui Xiang (Fructus Foeniculi), Mu Xiang (Radix Aucklandiae), etc. to treat periumbilical colic due to cold.
- It can be used in combination with Gui Zhi (Ramulus Cinnamomi) and Chen Pi (Tangerine Peel) to treat cold pain in the stomach and abdomen.
- It can be used in combination with Shan Zha (Hawthorn Fruit), Shen Qu (Medicated Leaven), Mai Ya (Fructus Hordei Germinatus), etc. to treat abdominal distension and pain caused by retention of food leading to stagnation of qi.
- It can be used in combination with San Leng (Rhizoma Sparganii), E Zhu (Rhizoma Curcumae), Bie Jia (Carapax Trionycis), etc. to treat abdominal mass caused by qi stagnation leads to blood stagnation or chronic malaria.
- At present, there is no literature report that Qing Pi has toxic effects, and no data is showing that taking it at the prescribed dose can cause serious adverse reactions.
Precautions and Warnings
- The dosage of Qing Pi should be controlled between 3-10g.
- It can be made into decoctions, pills, or powders.
- People who are allergic to Qing Pi should not take it.
- People with qi deficiency or body fluid consumption should not take it.
- Pregnant women should not take it.
- Breastfeeding women, children, the elderly, and the infirm should take it under medical supervision.
- The unprocessed Qing Pi is recommended for removing food retention, and the stir-fried Qing Pi is recommended for soothing the liver and alleviating pain.