A Wei (Asafoetida): Resolving Masses and Accumulations, Relieving Pain and Stopping Malaria, Anti-inflammatory and Anti-allergic

The Chinese medicinal A Wei is the oleoresin secreted by umbelliferous plants such as Ferula assa-foetida, F. sinkiangensis, and F. fukanensis. The parent plants grow in sandy soils and deserts, mainly distributed in Central Asia of the former Soviet Union, Iran, and Afghanistan; they are also produced in Xinjiang, China. At present, the A Wei sold on the herbal market is divided into imported and domestic types. Imported A Wei comes mainly from Iran, India, and Afghanistan; domestic A Wei is further divided into Xinjiang A Wei (mainly produced in Yining, Xinjiang) and Fukang A Wei (mainly produced in Fukang, Xinjiang).

A Wei is one of China's earliest imported medicinal materials. It was already recorded in the Xinxiu Bencao (Newly Revised Materia Medica) of the early Tang dynasty, where A Wei was also called "Xunqu." The Xinxiu Bencao states: "A Wei grows in the western regions and Kunlun; its seedlings, leaves, and root closely resemble Bai Zhi (Angelica Dahurica). Those made by pounding the root for juice and drying it into cakes in the sun are the finest; those cut from the root, threaded, and sun-dried are next. Its nature is extremely foul-smelling, yet it can stop foul odors—truly a remarkable substance."

A Wei has a special garlic-like odor, because its main components are sulfur ether compounds also found in garlic, which is why its smell is so strong. Traditional TCM holds that A Wei is bitter and pungent in taste, warm in nature, and non-toxic, entering the Liver, Spleen, and Stomach meridians. It resolves zheng-jia masses and accumulations, kills parasites, and stops malaria; it is mainly used for zheng-jia concretions and glomus, parasitic accumulation, food stagnation, chest and abdominal fullness and distending cold pain, malaria, and dysentery.

Modern pharmacology shows that A Wei has a biphasic regulatory effect on the uterus: when estrogen levels are high, its inhibitory effect on the uterus is enhanced; when progesterone levels are high, its excitatory effect is enhanced. In addition, A Wei can terminate pregnancy: its fat-soluble components achieve a 100% abortion rate in early pregnancy in mice and over 90% in mid-pregnancy. The Bencao Huiyan also records this effect of A Wei, holding that it can "resolve accumulation, induce abortion, kill parasites, and treat gu poisoning." A Wei also has anti-allergic, anti-inflammatory, and immunosuppressive effects. Its water decoction and water-alcohol extract can also reduce the heartbeat amplitude of isolated frog hearts while increasing heart rate.

A Wei is a commonly used herb in TCM external medicine and a standard herb for treating zheng-jia masses. Whether taken internally or applied externally, A Wei has the effect of dissolving tumors and glomus. Many famous TCM formulas for glomus, luoli (lymph node enlargement), and ru yan (breast cancer) contain A Wei, and some are directly named after it—for example, A Wei Hua Pi San and A Wei Hua Pi Gao from the Waike ZhengZong (Orthodox Manual of External Medicine), and A Wei Gao from the Neike Zhaiyao (Abstracts of Internal Medicine).

In the Waike ZhengZong, A Wei Hua Pi San is made from equal qian of A Wei, Chuanxiong (Sichuan Lovage), Danggui (Angelica), Baizhu (Atractylodes), Chifuling (Red Poria), Honghua (Safflower), and Biejia Jian (turtle-shell tips, roasted in butter and ground), together with eight qian of Dahuang (Rhubarb, wine-fried) and one liang of buckwheat flour (lightly fried), all ground into a powder. A Wei Hua Pi San can "dissolve glomus masses and remove cold and heat"; these conditions roughly correspond to today's cirrhosis of the liver and liver cancer. The A Wei Hua Pi Gao in the Waike ZhengZong is an external plaster still produced by Chinese patent medicine factories; in the past it was mainly used for breast lumps and lymph node enlargement, and today it is still commonly applied externally for mammary hyperplasia, breast cancer, lymphoma, and liver cancer.

A Wei is mostly combined with Chishao (Red Peony), Liangtoujian, Baijiezi (White Mustard Seed), Ruxiang (Frankincense), Moyao (Myrrh), Xionghuang (Realgar), Shexiang (Musk), and Chansu (Toad Venom) in treating tumor-glomus diseases. In such compound formulas, A Wei mainly functions to reduce swelling and stop pain. A Wei is not taken in decoction but in pills or powders, at a dose of 1–1.5 g each time; in larger formulas its single dose is even smaller.

A Wei's foul odor affects appetite, so those with weak Spleen and Stomach should use it cautiously. Also, because A Wei can induce abortion, pregnant women must avoid all Chinese medicines and patent medicines containing it.