Licorice

Glycyrrhiza glabra

Licorice consists of the underground parts, technically the rhizome and roots, of varieties of the European species Glycyrrhiza glabra L. (family Fabaceae), which possess a sweet yellow wood. Since significant quantities of licorice in the American market is imported from China, Glycyrrhiza uralensis Fisch. and other Asian species are also involved in the commercial supply. The drug is often called licorice root or glycyrrhiza. The root has been used since very ancient times as a flavoring and for its expectorant and demulcent properties in the treatment of coughs and colds. A very confusing situation exists concerning much so-called licorice candy. A great deal of it contains little or no licorice whatsoever but derives its flavor from anise oil. The flavors of licorice and anise do resemble each other, but in other respects, including potential toxicity, they are quite different. It is unfortunate that the more common, harmless anise flavor is almost always referred to as licorice.

Millions of pounds of licorice are imported into the United States annually, most of it originating in the eastern Mediterranean region. About 90 percent of it is used in flavoring tobacco product cigarettes, cigars, pipe tobaccos, and the like. The amounts used are very closely guarded trade secrets, but the noticeable sweetness and pleasant flavor of many commercial tobacco blends is due to licorice. It is also an ingredient in various pharmaceuticals, especially throat lozenges. Authentic licorice candy is far more popular in Europe, especially Britain, than in this country.

Much of the sweetness of licorice is due to glycyrrhizin, also known as glycyrrhizic acid, a saponin glycoside that occurs in the root in concentrations averaging between 5 and 9 percent. It is about fifty times sweeter than sugar and is available commercially in a form known as ammoniated glycyrrhizin. The medical literature refers to this condition as pseudoaldosteronism, meaning one similar to that brought about by excessive secretion of the adrenal cortex hormone, aldosterone. In the case of licorice, the syndrome is caused by glycyrrhizin, the structure and physiological effects of which are related to aldosterone or desoxycorticosterone. Symptoms resulting from excessive quantities include headache, lethargy, sodium and water retention, excessive excretion of potassium, high blood pressure, and even heart failure or cardiac arrest.

One popular herbal cough remedy contains 1 ounce of licorice root in a quart of water. Directions suggest that one-half pint be drunk at bedtime with additional quantities as needed. The half-pint dose could easily contain 0.5 gram of glycyrrhizin, and that daily amount might be doubled or tripled, depending on the frequency of use. At that rate of consumption, toxic effects could be observed after a single week. For persons suffering from high blood pressure or heart trouble, these could be serious. Since well-documented toxicity is associated with glycyrrhizin, deglycyrrhizinated licorice products have appeared in the American market in recent years. These may have some residual activity, but of course, the principal active constituent has been removed. Although licorice does have a flavor pleasing to many and may also have some utility in treating coughs as well as a number of other conditions, it must be remembered that it is also a potent botanical. Large doses over extended periods of time are quite toxic.

Licorice is the most remarkable herb with an affinity for the endocrine system. Glycyrrhizin has a similar structure to hormones produced by our adrenal glands, giving licorice an anti-inflammatory, anti-allergic and anti-arthritic effect similar (but without the side effects) of cortisone. The steroid-like compounds in licorice can change to estradiol and estrone which are estrogen precursors, giving licorice mild estrogenic properties -very helpful during the menopause. Licorice is useful for people coming off orthodox steroid drugs. Licorice has a well-documented reputation for healing ulcers. Licorice lowers stomach acid levels and relieves heartburn and indigestion. Licorice also acts as a mild laxative. Licorice can be used for irritation, inflammation and spasm in the digestive tract. Through its beneficial action on the liver, it increases bile flow and lowers cholesterol levels. In the respiratory system it has a similarly soothing and healing action, reducing irritation and inflammation and has an expectorant effect, useful in irritating coughs, asthma and chest infections. It has an aspirin-like action and is helpful in relieving fevers and soothing pain such as headaches. Its anti-allergenic effect is very useful for hay fever, allergic rhinitis, conjunctivitis and bronchial asthma. Possibly by its action on the adrenal glands, licorice has the ability to improve resistance to stress. It should be thought of during times of both physical and emotional stress, after surgery or during convalescence, or when feeling tired and run down.

The roots of licorice are widely used, not only in European herbal medicine but also in the traditional Chinese pharmacopoeia. In China and parts of Russia, the species used is G. uralensis; it is known in Chinese as gan cao. The scientific name for the genus refers to the sweet taste of the root. Licorice has been popular for flavoring foods and other medicinal herbs for many centuries. Hippocrates described its medicinal use, as did Pliny the Elder. A piece of licorice from the eighth century was recently discovered still to contain active principles. Licorice has been used to treat coughs and colds, and also as a digestive aid. Just to add to the confusion, some of the licorice candy made in the United States does not rely on licorice for its flavor. A recent case of licorice overdose, however, demonstrated that the popular candy Twizzlers (the black, not the red) contains some licorice, and natural candies imported from Europe often contain licorice rather than anise or other flavoring agents. The parts of the plant used are the dried roots and rhizomes, either peeled or unpeeled.

In Europe, the primary medicinal use of licorice is to treat coughs, colds, and other respiratory infections. Glycyrrhizinic acid seems to stop the growth of many bacteria and of viruses such as influenza A. It also stimulates the production of interferon. Chinese researchers agree that licorice is effective against cough and soothes the inflamed tissues of a sore throat. In fact, ancient Chinese texts summarize the uses of licorice rather well: "improve the tone of the 'middle Jiao' [digestive system] and replenish qi, to remove 'heat' and toxic substance, to moisturize the lungs and arrest coughing, and to relieve spasms and pain." Modern practitioners use different terminology, but the therapeutic benefits are quite similar.

Licorice has also been used extensively as a treatment for ulcers. Licorice prevents the secretion of gastric acid, reduces the activity of pepsin, and inhibits enzymes that dismantle prostaglandins. This leads to higher levels of prostaglandins in the stomach and upper intestine, allowing ulcers to heal more quickly. The activity of licorice on prostaglandin-regulating enzymes may explain why this herb protects stomach tissue against aspirin-induced damage in rat studies. A semisynthetic compound (carbenoxolone) derived from licorice has been compared to cimetidine in clinical trials and found less effective (52 percent improving compared to 78 percent on cimetidine). This agent does act to protect the colon, however, and is used to treat ulcerative colitis in China. Carbenoxolone also protects against colon cancer. Serious side effects that occur with licorice and with carbenoxolone led researchers to develop a deglycyrrhizinated licorice, DGL. In some studies, DGL (under the brand name Caved-S) was just as good as cimetidine at treating ulcers, but not all studies have shown consistently good results.

In Japan, physicians use licorice to treat chronic hepatitis B. Glycyrrhizin interferes with hepatitis B surface antigen and is synergistic with interferon against hepatitis A virus. It is also used at times to treat hepatitis C. Researchers have also demonstrated that licorice helps protect the liver from damage due to chemotherapy. At low doses, the herb stimulates the liver to manufacture cholesterol and excrete it in bile. This can help lower serum cholesterol levels. Licorice root has an effect on the organism similar to that of a steroid. Licorice slows the conversion of cortisol to cortisone, which increases and prolongs the action of this steroid hormone produced by the adrenal glands. This physiological activity can explain many of its undesirable effects as well as its medicinal benefits. In Russia, however, this property is put to use by administering licorice together with prescribed cortisone. This allows for a lower dose of the medication. Physicians in China may prescribe licorice alone or with cortisol to treat mild cases of Addison's disease, in which the body produces too little of this hormone. Glycyrrhizin also inhibits an enzyme that inactivates aldosterone, and its chronic use can mimic the serious condition of aldosteronism.

In China, licorice is considered a powerful antitoxin and is used as an aid in the treatment of pesticide poisoning. It may also curb Plasmodium falciparum, the parasite that causes malaria. Through its effects on adrenal steroids, licorice exerts anti-inflammatory activity. The licorice constituent known as LX immunosuppressant is also able to reduce hypersensitivity reactions and prolong the survival time of transplanted tissues. Glycyrrhizin has antioxidant and antitumor activity, but because of serious side effects it should not be used on a regular basis. Licorice has been used to ease symptoms of menopause. In one study, licorice attached to estrogen receptors. It did not, however, promote the growth of uterine cells as estrogen does, and it is not frequently used for this purpose in the United States. Topically, glycyrrhizin has been used in shampoo to treat excess oil secretion of the scalp. It has also been included in ointments used to treat skin inflammations.

The glycyrrhizin, which is 50 times sweeter than sugar, is mainly responsible for the plant's function in the respiratory system, acting as an expectorant and helping to prevent and ease coughing. This ingredient and its derivatives work as an anti-inflammatory. It is also largely the glycyrrhizin which gives an antiallergenic effect, especially when treating asthma. In the digestive system, licorice is known to have a protective effect on the liver, helping to detoxify and rid the body of unwanted elements. In China licorice has been used to treat hepatitis and jaundice. Licorice is also used to treat nausea, bloating, and vomiting, and is a valuable agent for the treatment of stomach ulcers. Licorice has a beneficial effect on the adrenal glands, supporting them in their function of healing the body. Licorice also has immuno-stimulant properties, and possibly anticarcinogenic principles. It is also available as a commercially prepared extract which is called "deglycyrrhizinated licorice" or "DGL." American research found DGL to be effective in the treatment of ulcers and less likely to raise blood pressure. As DGL is commercially prepared it is not strictly a home herbal remedy. Licorice obtained and prepared at home should still be regarded with caution since it should not be taken in conditions of high blood pressure. Chinese properties are sweet and neutral if used raw sweet and warming if dry-fried before using in a decoction.

Other names

• Chinese Licorice
• Gan Cao
• Kan-ts'ao
• Kuo-lao
• Licorice Root
• Ling-t'ung
• Liquorice
• Mei-ts'ao
• Mi-kan
• Mi-ts'ao
• Sweet Licorice
• Sweet Wood
• Yasti Madhu

Parts used

Root.

Uses

Traditional uses - Licorice has long been valued for its medicinal uses.. Licorice was taken in ancient Greece for asthma, chest problems, and canker sores.
Soothing herb - Inflammatory conditions of the digestive system, such as canker sores, gastritis, peptic ulceration, and excessive acid problems, benefit from licorice's demulcent and healing properties, as do many chest complaints, arthritis, inflamed joints; and some skin problems. Licorice is also soothing for inflamed eyes.
Adrenal stimulation - Licorice stimulates the adrenal glands, helping in Addison's disease where the adrenal glands cease to function normally.
Constipation - Licorice is useful as a gentle laxative.
Licorice is also used to treat excessive hair.

Habitat & cultivation

Growing wild in Southeastern Europe and Southwestern Asia, licorice is now extensively cultivated. Licorice is propagated by dividing the roots in spring. The root of 3-4-year-old plants is unearthed in late autumn.

Research

Adrenal agent - Research shows that on being broken down in the gut, glycyrrhizin has an anti-inflammatory and antiarthritic action similar to hydrocortisone and other corticosteroid hormones. Licorice stimulates the production of hormones by the adrenal glands and reduces the breakdown of steroids by the liver and kidneys.
Glycyrrhizin - Research in Japan in 1985 showed that glycyrrhizin was effective in the treatment of chronic hepatitis and liver cirrhosis.
Protective mucus - Licorice as a whole reduces stomach secretions but produces a thick protective mucus for the lining of the stomach, making it a useful remedy in inflammatory stomach conditions.
Isoflavones - The isoflavones are known to be estrogenic.

Constituents

Licorice contains saponins, glycosides (inc. glycyrrhizin), estrogenic substances, coumarins, flavonoids, sterols, choline, asparagine, volatile oil.

How much to take

A licorice preparation without the glycyrrhizin circumvents certain potential safety problems as explained below. The result is known as deglycyrrhizinated licorice (DGL), which is used for conditions of the digestive tract, such as ulcers. For best effects, one 200-300 mg tablet is chewed three times per day before meals and before bed. For mouth ulcers 200 mg of DGL powder can be mixed with 200 ml warm water, swished in the mouth for three minutes, and then spit out. Licorice may also be taken as a tincture in the amount of 2-5 ml, three times daily. For respiratory infections, chronic fatigue syndrome, or topically for herpes, extracts containing glycyrrhizin should be used. Encapsulated licorice root capsules can be used, 5-6 grams per day. Alternatively, a tea can be made by boiling 1/2 ounce of root in 1 pint of water for fifteen minutes, drinking two to three cups of this per day. Long-term internal use of high doses of glycyrrhizin-containing products should be taken only with caution and under the supervision of a nutritionally oriented doctor. Licorice creams or gels can be applied directly to herpes sores three to four times per day.

Side effects

Licorice products that still contain the glycyrrhizin may increase blood pressure and cause water retention. Some people are more sensitive to this effect than others. Long-term intake of products containing more than 1 gram of glycyrrhizin (which is the amount in approximately 10 grams of root) daily is the usual amount required to cause these effects. As a result of these possible side effects, long-term intake of high levels of glycyrrhizin are discouraged and should only be undertaken if prescribed by a qualified health care professional. Deglycyrrhizinated licorice extracts do not cause these side effects because there is no glycyrrhizin in them.

Applications

ROOT:

TINCTURE - Use as an anti- inflammatory for arthritic or allergic conditions, as a digestive stimulant, or for lung disorders. Prescribed for gastric inflammation or to encourage adrenal function after steroid therapy. Helps disguise the flavor of other medicines.

DECOCTION - Prescribed to reduce stomach acidity in ulceration.

SYRUP - Take a syrup made from the  decoction as a soothing expectorant for asthma and bronchitis.

FLUID EXTRACT - Let juice sticks dissolve slowly in an equal volume of water to produce a strong extract that can be used as the decoction, tincture, or syrup.

TONIC WINE - Macerate a piece of root in gin or vodka for a few weeks to produce a tonic wine: drink in small doses after meals.

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