Qin Pi commonly known as Cortex Fraxini or Ash Bark is the bark of Fraxinus. It first appeared in <Shennong Ben Cao Jing> in the late Western Han Dynasty (about 100 BC).
Fraxinus is a deciduous tree of the family Oleaceae. There are about 70 species of this genus, which are mainly distributed in temperate regions of the northern hemisphere. It is an important source of biological wax. Its trunk can be made into furniture and agricultural tools.
The Qin Pi referred to herein is the bark of Fraxinus rhynchophylla, Fraxinus chinensis, Fraxinus szaboana, or Fraxinus stylosa.
Fraxinus rhynchophylla often grows on river banks, hillsides, or roadsides below 1,500 meters above sea level. It is distributed in Russia, Korea, and China and has not yet been artificially introduced and cultivated.
Fraxinus chinensis is also known as Chinese ash and often grows in mountains or woods at an altitude of 800-1,600 meters.
Fraxinus szaboana often grows in mountains at an altitude of 1,000 meters. It is distributed in the provinces of China’s Yangtze River Basin and Yellow River Basin, and has not yet been artificially introduced and cultivated.
Fraxinus stylosa is a unique plant in China, which is distributed in Gansu, Sichuan, Henan, and Shaanxi of China. It often grows in hillsides or woods at an altitude of 1,300-3,200 meters.
In spring and autumn each year, people peel off the bark of Fraxinus, dry them in the sun, cut them into pieces, and make them into Chinese herbs.
Qin Pi contains esculin, esculetin, fraxetin, fraxin, lignins, iridoids, phenylethanol glycosides, flavonoids, phenolic acids, ginsenosides, β-sitosterol, daucosterol, and ursolic acid. The grayish-white Qin Pi with spots is the best.
According to <Compendium of Materia Medica>, the medicinal property of Qin Pi is relatively cold, with a bitter and astringent taste. It has a certain therapeutic effect on the pathological changes of the liver, gallbladder, and large intestine meridians.
In Chinese medicine, Qin Pi is often used to clear heat and dry dampness, induce astringency and relieve diarrhea, improve eyesight, treat bacterial dysentery, enteritis, conjunctivitis, blepharitis, chronic tracheitis, and whooping cough. It is an important component of Bawei Qinpi Wan.
Health benefits of Qin Pi
- Anti-inflammation, anti-oxidation, and anti-tumor.
- Inducing diuresis and promoting uric acid excretion.
- Inhibiting xanthine oxidase activity, reducing serum uric acid levels, and anti-hyperuricemia.
- Anti-allergen and inhibiting edema induced by carrageenan, croton oil, dextran, or yeast in rats.
- Reducing the damage of CCL4 to liver tissue and protecting the liver.
- Inhibiting the central nervous system and having sedative and analgesic effects.
- Clearing heat and drying dampness, treating diarrhea and tenesmus caused by damp-heat or heat toxins.
- Clearing damp-heat in lower energizer, treating abnormal leucorrhea caused by the downward flow of damp-heat.
- Purging the liver fire, treating redness and swelling of the eyes, nebulae, and blurred vision caused by the stagnation of liver-fire or wind-heat.
- Inhibiting Staphylococcus aureus, Escherichia coli, Shigella flexneri, Shigella sonnei, K. catarrhalis, and Neisseria diplococcus.
- The study found that esculetin can relieve cough and asthma and eliminate phlegm.
Qin Pi is used with other Chinese herbs
- It with Bai Tou Weng (Radix Pulsatillae), Huang Lian (Rhizoma Coptidis), and Huang Bai (Cortex Phellodendri) can treat diarrhea and tenesmus caused by damp-heat.
- It with Mu Dan Pi (Cortex Moutan) and Dang Gui (Radix Angelicae Sinensis) can treat the abnormal leucorrhea caused by the downward flow of damp-heat.
- It with Zhi Zi (Fructus Gardeniae) and Dan Zhu Ye (Lophatherum) can treat redness and swelling of the eyes, nebulae, and blurred vision caused by the stagnation of liver-fire.
- It with Qin Jiao (Radix Gentianae Macrophyllae) and Fang Feng (Radix Saposhnikoviae) can treat inflamed eyes and nebulae caused by wind-heat.
- It with Huang Bai (Cortex Phellodendri), Da Huang (Radix et Rhizoma Rhei), Yin Chen (Capillary Wormwood), and Pu Gong Ying (Dandelion) can treat acute hepatitis.
Side effects of Qin Pi
Qin Pi has been used clinically for many years, with almost no side effects.
Long-term use of it may cause symptoms such as frequent urination and urgency.
Precautions of Qin Pi
- The dosage of Qin Pi should be controlled at 6-12g.
- It can be made into an oral decoction or be used to soak and wash the affected part.
- People with deficiency-cold in spleen and stomach should not take it.
- People with poor appetite or loose stools should not take it.