Dr. Zhongzhen Zhao
Hong Kong Baptist University, 7 Baptist University Road, Kowloon Tong, Hong Kong
Dr. Li LIANG
Hong Kong Baptist University, 7 Baptist University Road, Kowloon Tong, Hong Kong
Licorice is known as the “Minister of the Country”, which shows the high status of licorice in traditional Chinese medicine.
Licorice we consume comes from the roots and rhizomes of species of the genus Glycyrrhiza in the Fabaceae family. Currently, three species of licorice are recorded in the “Chinese Pharmacopoeia” as medicinal resources, namely Glycyrrhiza uralensis Fisch., G. inflata Bat., and Glycyrrhiza glabra L. G. uralensis is also called Ural licorice. The name brings to mind the Ural Mountains and the Ural River on the dividing line between Europe and Asia. G. glabra is the species most commonly used.
Licorice has a long history in both Eastern and Western cultures. In addition to medicinal purposes, licorice is also eaten and used as an additive in foods, particularly preserved fruits and tobacco.
In some European countries, the fresh and dried roots are simply chewed as a snack. For Chinese medicine, the roots and rhizomes can be used medicinally in raw or processed form.
In the Compendium of Materia Medica, licorice is recorded in the “mountain herb” category. It is so commonly used that in traditional Chinese medicine, there is a saying that roughly translates as, “ten prescriptions, nine with licorice”.
Licorice is of great importance as a harmonizer in Chinese medicine formulas. Indeed, if there is a single word that can represent licorice, it should be harmony. Licorice coordinates and harmonizes the other ingredients in a formula so that they work together to achieve therapeutic effects. “Harmony” is also a concentrated expression of the core spirit of Chinese traditional culture. Harmony in a family can bring prosperity, and harmony in a formula can cure all diseases.
Another function of licorice concerns side effects. Regardless of whether any medicine–Chinese or Western– is effective, we should pay attention to whether there are any side effects.
Licorice can moderate the strong, sometimes toxic, properties of other medicines. There is a saying that the reason traditional Chinese medicine has less toxicity and fewer side effects than other medicines is that licorice is found in almost all traditional Chinese medicinal formulas. Zhen Quan in the Tang Dynasty described it more specifically in “The Nature of Medicine (Yao Xing Fu)”, that licorice can detoxify 1200 kinds of plants and trees. Although 1200 sounds like an exaggeration, the results of modern pharmacological research and clinical practice are now showing that licorice does have a certain detoxification effect on a wide variety of drugs and food toxins.
Licorice as Protagonist
In addition to harmonizing the nature of other medicinals, licorice has its own unique medicinal properties. Licorice can not only play a supporting role, but also be a protagonist—perhaps even a hero.
Licorice was first recorded in “Shen Nong’s Materia Medica (Shen Nong Ben Cao Jing)” and was listed as an “upper rank” herb. In Chinese medicine, this term refers to tonic medicines that nourish the body, prolong life, and can be used safely for a long time. According to traditional Chinese medicine theory, licorice supplements the spleen, boosts Qi, clears heat, resolves toxins, dispels phlegm, and relieves cough.
Licorice mainly boosts the Qi of the heart and spleen. For example, the representative formula for Qi-boosting is Si Jun Zi Decoction. In this formula, processed licorice, ginseng, Atractylodes, and Poria are used to tonify spleen-stomach Qi deficiency.
Another representative formula, Zhi Gan Cao Decoction, is for supplementing the heart Qi; it is also known as Fu Mai Decoction. It can restore the pulse, stop heart palpitations, nourish yin, and nourish blood. In this formula, licorice is in processed form. The processed licorice originally used was equivalent to stir-fried licorice, which means the cut medicinal materials are dry-roasted in an open pan. Nowadays, it is more common to use honey-fried licorice; in this case the licorice is similarly roasted, but with the addition of honey.
Gan Mai Da Zao Decoction nourishes the heart and calms the mind. It is commonly used in the treatment of menopausal syndrome, also known as perimenopausal syndrome. Menopause symptoms in gynecology are experienced by almost every woman, but the degree varies. I have an American friend who was suffering from menopause and felt very uncomfortable. She told me about her symptoms, and I recommended Gan Mai Da Zao Decoction. There are only three herbs in this formula: licorice (“Gan”), blighted wheat (“Mai”) and jujube (“Da Zao”). This friend has taken it a few times and it was very effective. Her symptoms were very typical, and Gan Mai Da Zao Decoction is just the right formula to relieve them.
Both Chinese and Western medicine use licorice, particularly to remove phlegm and relieve a cough.
I was weak when I was a child, and I often had a cold or a cough. My father was a Western doctor, and he often prescribed licorice tablets and compound licorice syrup for me.
The sweetness of licorice comes from glycyrrhizin, one of the main active ingredients of licorice. In Western medicine, glycyrrhizin is used as an expectorant, as well as a flavoring agent and a binding agent in pharmaceuticals. Glycyrrhizic acid and salts of glycyrrhizinate acid such as ammonium glycyrrhizinate and zinc glycyrrhizinate can also be used to treat chronic hepatitis.
While licorice has a wide range of uses, too much may cause side effects. An overdose will affect the metabolism of potassium ions and sodium ions in the body, and symptoms such as edema may occur.
Production
China is one of the main producers of licorice. Licorice is cultivated across almost the entire northern part of China, including the northeast, north and northwest regions. Among them, inner Mongolia and Ningxia are the most productive areas for licorice.
The ancients discussed the original production area of licorice. In the Northern and Southern Dynasties, the “Bielu of Famous Doctors” records that licorice was growing in today’s Hexi Corridor and Shaanxi Province, China. Li Shizhen described: “The branches and leaves of licorice are like the locust tree… Licorice is produced along the east and west sides of the Yellow River (mainly referred to Shanxi and Shaanxi today)”. This is true! Both licorice and locust are in the Fabaceae family, so their leaves and flowers look similar, even though their growing habits are different. Due to the lack of knowledge of the licorice resources in Inner Mongolia, Xinjiang and foreign countries in ancient times, there is no record of licorice in these areas in the ancient Chinese medicine books.
Licorice mainly grows in semi-desert areas, and its underground root is deep and extremely well developed. This means the plant itself is valuable as a windbreak to prevent soil erosion, in addition to producing a valuable crop.
Although the distribution area of licorice in China is not small, the resources are relatively limited now. Over-harvesting caused a sharp decrease in its wild resources, and over-grazing slowed down its growth. At the same time, over the past few years, there has been an increasing demand for licorice. As a result, there is a huge gap between supply and demand.
King of Licorice
Professor Wang Wenquan, known as the “King of Licorice in China”, has been doing research on traditional Chinese medicine resources for many years. Agriculture is his specialty, and he has been studying licorice for more than 30 years.
In the past ten years, I have conducted many field investigations with Professor Wang. We have been to the Ordos Plateau where Genghis Khan fought. The licorice there grows very well. The skin of its root is as red and shiny as a jujube, the texture is brittle, and the cross-section is bright yellow and white. There I even saw a large licorice root that was more than 2 meters long.
Professor Wenquan Wang has visited Central Asia, Kazakhstan and other places where licorice and its relatives grow. He told me that there are about 20 species in the Glycyrrhiza genus in the world. They are distributed all over the world, with the greatest number of species in Eurasia and the greatest number of plants in central Asia. In addition, licorice grows throughout Pakistan, Turkmenistan, Tajikistan, Kyrgyzstan and Uzbekistan.
Now China has started to import licorice from these countries. However, in the long run, artificial cultivation should be strengthened, in order to bridge the gap between supply and demand, as well as protect the wild recourses.
In 2004, when we compiled the Encyclopeida of Medicinal Plants, we did a statistical analysis. At that time, we found that more than 6,000 research papers on licorice had been published in international journals. Licorice is not only one of the most used medicinal herbs in ancient formulas, but also one of the most studied medicines in modern research.
Licorice has a high status, a great amount of usage, a wide range of applications, and unlimited potential.
