Bai Wei commonly known as Radix Cynanchi Atrati or Swallowwort Root is the root and rhizome of Cynanchum atratum or Cynanchum versicolor, which is a perennial herb belonging to the family Asclepiadaceae. It first appeared in <Shennong Ben Cao Jing> in the late Western Han Dynasty (about 100 BC).
There are about 300 species of Cynanchum, which are distributed in the tropical, subtropical, and temperate regions of eastern Africa, the Mediterranean region, and Eurasia.
Cynanchum atratum likes a warm and humid environment and often grows in riversides, wastelands, grasses, or ravines at an altitude of 100-1,800 meters. It can be found in China, Japan, and North Korea.
Cynanchum versicolor often grows in mountains, thickets, or riversides below 800 meters above sea level. It is distributed in Liaoning, Hebei, Henan, Shandong, Shanxi, and Anhui provinces in China.
In the spring and autumn of each year, people gather the roots and rhizomes of Cynanchum atratum or Cynanchum versicolor, remove their impurities, wash them in water, dry them in the sun, cut them into thin slices, and make them into Chinese herbs.
Bai Wei contains saponins such as glaucoside A, glaucoside H, cynatratoside A, cynatratoside C, cynatratoside E, mooreanosid H, sublanceoside L2, sublanceoside H2. It also contains cynanchol, volatile oil, aromatic compounds, succinic acid, suberic acid, and azelaic acid. Generally, the brownish-yellow and thick Bai Wei is the best.
According to <Compendium of Materia Medica>, the medicinal property of Bai Wei is relatively cold, with a bitter and salty taste. It has a certain therapeutic effect on the pathological changes of the stomach, liver, and kidney meridians.
In traditional Chinese medicine, Bai Wei is used to clear asthenic fever and cool blood, promote urination and remove toxin, treat cough, fever, hematuria, urinary tract infection, nephritis, edema, bronchitis, rheumatic arthritis, gastroenteritis, pharyngitis, abscess, blood vessel Inhibitory syncope, sequelae of cerebral infarction, erythematous limb pain, tuberculosis, and snakebite. It is an important component of Nujin wan and Kunbao Wan.
Health benefits of Bai Wei
- Anti-inflammation, anti-allergy, and anti-depression.
- Scavenging DPPH free radicals and promoting the reduction of iron ions to ferrous ions.
- Inhibiting pneumococcal bacteria and having antipyretic and analgesic effects.
- Enhancing myocardial contractility, slowing down heart rate, and treating congestive heart failure.
- Inducing apoptosis of A549 lung cancer cells and inhibiting the growth of HeLa cells and SW480 cells cultured in vitro.
- Alleviating symptoms in the later stage of febrile diseases, such as fever at night, chills in the early morning, hot flashes, and febrile sensation in the palms and soles.
- Treating persistent low fever, syncope, and fever caused by postpartum blood deficiency.
- Treating high fever, polydipsia, dizziness, and crimson tongue caused by warm pathogens attacking nutrient system.
- Inducing diuresis, relieving difficult and painful urination, and treating hematuria.
- Removing heat toxins, relieving skin swelling and pain, and treating sores and abscesses caused by heat toxins.
- Clearing lung heat, relieving throat swelling and pain, cough caused by lung heat.
- Nourishing yin, treating fever, dry throat, thirst, and irritation caused by yin deficiency.
- Studies have found that its water extract can relieve asthma and eliminate phlegm.
Bai Wei is used with other Chinese herbs
- It with Mu Tong (Caulis Akebiae), Hua Shi (Talcum), and Shi Wei (Folium Pyrrosiae) can treat painful urination and dysuria.
- It with Jin Yin Hua (Flos Lonicerae), Jie Geng (Radix Platycodi), and Shan Dou Gen (Radix Sophorae Tonkinensis) can clear heat and remove toxin, and relieve throat swelling and pain.
- It with Yu Zhu (Rhizoma Polygonati Odorati), Dan Dou Chi (Fermented Soybeans), and Bo He (Mentha) can alleviate fever, dry throat, thirst, and irritation caused by yin deficiency.
- It with Ren Shen (Radix Ginseng), Dang Gui (Radix Angelicae Sinensis), and Zhi Gan Cao (Radix Glycyrrhizae Preparata) can treat blood vessel Inhibitory syncope.
- It with Ze Lan (Lycopus Lucidus), Jin Yin Hua (Flos Lonicerae), Xuan Shen (Radix Scrophulariae), and Bai Shao (White Peony Root) can relieve erythematous limb pain.
Side effects of Bai Wei
Excessive use of it may cause cardiac glycosides poisonings, such as palpitations, nausea, vomiting, dizziness, headache, diarrhea, or salivation.
Precautions of Bai Wei
- The dosage of Bai Wei should be controlled between 4.5-9g.
- It can be made into a decoction, pills, or mashed for external use.
- Patients with cardiac atrioventricular block, acute endocarditis, hypokalemia, hypercalcemia, or acute myocardial infarction should not take it.
- It should not be used together with calcium salt drugs or sodium-saving and potassium-removing drugs.
- People with deficiency-cold in the spleen and stomach should not take it.
- People with poor appetite or loose stools should not take it.
- Pregnant women and children should not take it.