The Medicinal Value of Mugua (Chinese Quince)

Among Chinese medicinal materials there is an herb called mugua. It shares its name with the edible papaya we commonly eat, but the two are actually different.

The medicinal mugua is the nearly ripe dried fruit of Chaenomeles speciosa (Rosaceae), grown mainly in Anhui, Hunan, Hubei, Zhejiang and Sichuan. The mugua produced in Xuancheng, Anhui, is the most authentic, hence it is also called “Xuan mugua.”

In addition, the mugua produced in Ziqiu, Hubei, and Chun’an, Zhejiang, is also of good quality and high medicinal value; that from Chun’an is also called Chun mugua. But production in these areas is not high; because clinical demand is large, the mugua sold on the medicinal market today is not entirely from the above places. Qijiang in Chongqing is China’s highest-producing area for mugua; Qijiang formerly belonged to Sichuan, so its mugua is conventionally called “Chuan mugua.” The papaya we eat daily, on the other hand, is also called fanmugua; it is the fruit of Carica papaya (Caricaceae), native to South America and only introduced into China in the 17th century.

In my hometown there is a rural saying: “For pain in the waist and legs, mugua works.” The main functions of medicinal mugua are to relax the tendons and activate the collaterals, diffuse bi (obstruction) and stop pain; its efficacy for aching pain in the waist, knees and legs has long been deeply rooted in people’s minds. So in rural areas, many elderly people know that mugua treats spasm and bi pain caused by wind-dampness.

In the Shanghan Lun there is a formula called “Shaoyao Gancao Tang,” composed of just Baishao (White peony) and Gancao (Licorice). It is also called the “Crutch-Discarding Decoction,” a name describing its efficacy for leg pain. There is also a folk “Shaoyao Mugua Tang,” roughly composed of: Baishao 30 g, Mugua 15 g, Jixueteng (Spatholobus) 15 g, Gegen (Pueraria) 10 g, Gancao 10 g. This formula is built on Shaoyao Gancao Tang by adding herbs such as mugua, Spatholobus and Pueraria that relax tendons, activate collaterals and stop pain; it also treats bi pain well. It is not limited to leg pain—pain in other areas may also be treated with it. Adding to this formula Jishiteng (Paederia), Sigualuo (Luffa sponge), Ruxiang (Frankincense), Moyao (Myrrh), Quanxie (Scorpion), Wugong (Centipede), and some anti-cancer herbs such as ChongLou (Paris polyphylla), Baihuasheshecao (Oldenlandia) and Banzhilian (Scutellaria barbata), it may also be used for pain caused by bone metastases in cancer patients.

Mugua is a plant that can serve both as medicine and food. Its fruit mainly contains malic acid, tartaric acid, citric acid, oleanolic acid and saponins. Animal experiments confirm that mugua is not only non-toxic but also has a good liver-protective effect. It can prevent liver damage caused by carbon tetrachloride in experimental animals, prevent hepatocyte swelling and ballooning degeneration, promote hepatocyte recovery, and significantly lower serum ALT. Thus mugua can be used as a liver-protecting herb in TCM formulas; used together with liver-protecting herbs such as corn silk, lingzhi (Reishi) and fuling (Poria), its protective effect is even better.

Modern pharmacological experiments confirm that mugua has a strong antibacterial effect. It is sensitive to Shigella dysenteriae, Shigella flexneri, Shigella sonnei and their variants, pathogenic E. coli, ordinary E. coli, Proteus, Enterobacter aerogenes, Staphylococcus albus, Staphylococcus aureus, Pseudomonas aeruginosa, and alpha-hemolytic streptococci.

This result also confirms the claim in ancient TCM texts that mugua treats summerheat-damp vomiting and diarrhea. TCM holds that mugua, warm and aromatic, enters the spleen meridian, excels at harmonizing the stomach and transforming dampness, and relaxes tendons to stop pain; thus it is commonly used for abdominal pain, vomiting, diarrhea and tendon spasm caused by dampness obstructing the middle jiao. If the patient tends toward cold-dampness, mugua is often combined with Wuzhuyu (Evodia), Xiaohuixiang (Fennel) and Zisu (Perilla); if toward summerheat-dampness, it is often combined with Can Sha (silkworm excrement), Yiyiren (Coix) and Huanglian (Coptis). In the Huoluan Lun there is a famous formula, “Can Shi Tang” (Silkworm Excrement Decoction), the representative formula for summerheat-dampness—what TCM calls summerheat-dampness is mostly intestinal pathogenic-microbial infection during the summer.

Mugua also treats beriberi edema. TCM holds that mugua warms and unblocks the meridians, dispels dampness and relaxes tendons, so it can treat beriberi edema. In the Zhu Shi Ji Yan Fang there is a “Jiming San” (Rooster-Crow Powder), composed of “seven Binglang (Areca nut), one liang each of Chenpi (Tangerine peel) and Mugua, two qian of Wuzhuyu (Evodia), half a qian of Jiegeng (Platycodon), half a qian of Shengjiang (Fresh ginger, with skin), and three qian of Zisu stems and leaves.” “The above are coarsely ground and divided into eight doses. The night before, simmer in three large bowls of water over low heat to one and a half bowls, remove the dregs; boil the dregs again in two bowls of water to one small bowl, combine the two decoctions, set by the bedside, and on the next day take in two or three doses around the fifth watch, taken cold; in winter it may be slightly warmed; after taking, press down with cakes. If not all is taken, leave it for the next day to finish slowly. By dawn after taking this medicine, the stool will pass about a bowl of black watery feces, which means the cold-damp toxin contracted by the kidney is being discharged. Around breakfast time, pain stops and swelling subsides; only eat slowly and lightly, waiting for the medicinal force to pass.” This formula treats “people struck by wind-dampness that streams into the feet, with pain unbearable so that the feet must be suspended by ropes, incessant crying out, and swollen, engorged tendons and vessels”.

Mugua has a diuretic effect; modern pharmacological research has found it also inhibits Ehrlich ascites carcinoma. But TCM mainly uses mugua’s action of diffusing and unblocking bi pain; nearly all kinds of wind-damp bi pain and numbness may be treated with it. Mugua Wan, Mugua Pian and Mugua Jiu are all common medicines for wind-damp bi pain.

Mugua can also treat sores and swellings. As the Suixi Jushi Yinshi Pu records: “Take mugua alone as powder, and take three qian daily with Tufuling (Smilax)”; this treats “mei chuang jie du” (syphilitic nodules). The Gujin Yitong records: “Dry mugua ground to powder, mixed with the mucus on a fresh fish and applied, covered with paper”; this treats “fanhua zhi” (everting internal hemorrhoids).