Glycyrrhizin
Encyclopedia
Glycyrrhizin is the main sweet-tasting
compound from liquorice root. It is 30–50 times as sweet as sucrose
(table sugar). Pure glycyrrhizin is odorless.
In chemical terms, glycyrrhizin is a triterpenoid
saponin
glycoside
of glycyrrhizic (or glycyrrhizinic) acid. Upon hydrolysis, the glycoside loses its sweet taste and is converted to the aglycone glycyrrhetinic acid
plus two molecules of glucuronic acid
. The acid form is not particularly water-soluble, but its ammonium
salt is soluble in water at pH
greater than 4.5.
Although sweet, the taste sensation of glycyrrhizin is different from that of sugar. The sweetness of glycyrrhizin has a slower onset than sugar has, and lingers in the mouth for some time. Unlike the artificial sweetener aspartame
, glycyrrhizin maintains its sweetness under heating.
In the United States
, glycyrrhizin is classified as "generally recognized as safe
" as a flavoring agent, although not as a sweetener. Glycyrrhizin is used as a flavoring in some candies
, pharmaceuticals, and tobacco
products.
The European Union
suggests people should not consume any more than 100 mg of glycyrrhizic acid a day, equivalent to approximately 50 g of liquorice sweets.
In Japan
, where concern over the safety of artificial sweeteners during the 1970s led to a shift towards plant-derived sugar substitutes, glycyrrhizin is a commonly used sweetener, often used in combination with another plant-based sweetener, stevia
. However, the Japanese government has asked its citizens to limit their consumption to 200 milligrams per day.
and edema
(water
retention). These effects are related to the inhibition of cortisol
metabolism within the kidney, and the subsequent stimulation of the mineralocorticoid
receptors. Thus, consumption of black licorice can mimic disorders of excess aldosterone
.
Glycyrrhizin and other licorice root products have been used for numerous medical purposes, in particular, treatment of peptic ulcer
s and as an expectorant. The triterpene derivative of hydrolyzed
glycyrrhizin glycyrrhetinic acid
is itself effective in treatment of peptic ulcer. According to MedlinePlus
and the Natural Medicines Comprehensive Database, licorice is "possibly effective" for dyspepsia
in combination with other herbs, but there is "insufficient evidence" to rate its effectiveness for other conditions. Regarding stomach ulcers, specifically, there is "some evidence...that specially prepared licorice will speed the healing of stomach ulcers".
An un-blinded study of 82 patients from the early 1980s, published in the British Medical Journal
, reported that Caved-S had a therapeutic effect is similar to that of cimetidine
in the treatment of gastric ulcers.
Although licorice may produce anti-inflammatory
effects, it is uncertain as to whether that is due to glycyrrhizin, glycyrrhetinic acid, or some other licorice derivative.
Researchers have recently demonstrated doses of licorice root extract, delivering the constituent glycyrrhizin in amounts similar to that contained in standard medical doses of the root, rapidly and significantly lowered levels of circulating testosterone
in males.
Glycyrrhizin inhibits liver cell injury caused by many chemicals and is used in the treatment of chronic hepatitis
and cirrhosis
in Japan. It also inhibits the growth of several DNA and RNA viruses, inactivating herpes simplex
virus particles irreversibly.
Sweetness
Sweetness is one of the five basic tastes and is almost universally regarded as a pleasurable experience. Foods rich in simple carbohydrates such as sugar are those most commonly associated with sweetness, although there are other natural and artificial compounds that are sweet at much lower...
compound from liquorice root. It is 30–50 times as sweet as sucrose
Sucrose
Sucrose is the organic compound commonly known as table sugar and sometimes called saccharose. A white, odorless, crystalline powder with a sweet taste, it is best known for its role in human nutrition. The molecule is a disaccharide composed of glucose and fructose with the molecular formula...
(table sugar). Pure glycyrrhizin is odorless.
In chemical terms, glycyrrhizin is a triterpenoid
Triterpenoid
Triterpenoids are terpenoid derviatives of triterpene molecules.They may have useful anti-cancer properties.Notable examples*Betulinic acid, possible anti-cancer drug*Bardoxolone methyl, inflammation modulator*Triterpenoid saponins...
saponin
Saponin
Saponins are a class of chemical compounds, one of many secondary metabolites found in natural sources, with saponins found in particular abundance in various plant species...
glycoside
Glycoside
In chemistry, a glycoside is a molecule in which a sugar is bound to a non-carbohydrate moiety, usually a small organic molecule. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. These can be activated by enzyme...
of glycyrrhizic (or glycyrrhizinic) acid. Upon hydrolysis, the glycoside loses its sweet taste and is converted to the aglycone glycyrrhetinic acid
Glycyrrhetinic acid
Glycyrrhetinic acid is a pentacyclic triterpenoid derivative of the beta-amyrin type obtained from the hydrolysis of glycyrrhizic acid, which was obtained from the herb liquorice. It is used in flavoring and it masks the bitter taste of drugs like aloe and quinine. It is effective in the treatment...
plus two molecules of glucuronic acid
Glucuronic acid
Glucuronic acid is a carboxylic acid. Its structure is similar to that of glucose. However, glucuronic acid's sixth carbon is oxidized to a carboxylic acid...
. The acid form is not particularly water-soluble, but its ammonium
Ammonium
The ammonium cation is a positively charged polyatomic cation with the chemical formula NH. It is formed by the protonation of ammonia...
salt is soluble in water at pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
greater than 4.5.
Although sweet, the taste sensation of glycyrrhizin is different from that of sugar. The sweetness of glycyrrhizin has a slower onset than sugar has, and lingers in the mouth for some time. Unlike the artificial sweetener aspartame
Aspartame
Aspartame is an artificial, non-saccharide sweetener used as a sugar substitute in some foods and beverages. In the European Union, it is codified as E951. Aspartame is a methyl ester of the aspartic acid/phenylalanine dipeptide. It was first sold under the brand name NutraSweet; since 2009 it...
, glycyrrhizin maintains its sweetness under heating.
In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, glycyrrhizin is classified as "generally recognized as safe
Generally recognized as safe
Generally recognized as safe is an American Food and Drug Administration designation that a chemical or substance added to food is considered safe by experts, and so is exempted from the usual Federal Food, Drug, and Cosmetic Act food additive tolerance requirements.-History:On January 1, 1958,...
" as a flavoring agent, although not as a sweetener. Glycyrrhizin is used as a flavoring in some candies
Candy
Candy, specifically sugar candy, is a confection made from a concentrated solution of sugar in water, to which flavorings and colorants are added...
, pharmaceuticals, and tobacco
Tobacco
Tobacco is an agricultural product processed from the leaves of plants in the genus Nicotiana. It can be consumed, used as a pesticide and, in the form of nicotine tartrate, used in some medicines...
products.
The European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
suggests people should not consume any more than 100 mg of glycyrrhizic acid a day, equivalent to approximately 50 g of liquorice sweets.
In Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, where concern over the safety of artificial sweeteners during the 1970s led to a shift towards plant-derived sugar substitutes, glycyrrhizin is a commonly used sweetener, often used in combination with another plant-based sweetener, stevia
Stevia
Stevia is a genus of about 240 species of herbs and shrubs in the sunflower family , native to subtropical and tropical regions from western North America to South America. The species Stevia rebaudiana, commonly known as sweetleaf, sweet leaf, sugarleaf, or simply stevia, is widely grown for its...
. However, the Japanese government has asked its citizens to limit their consumption to 200 milligrams per day.
Health effects
The most widely reported side-effects of glycyrrhizin use are hypertensionHypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
and edema
Edema
Edema or oedema ; both words from the Greek , oídēma "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin or in one or more cavities of the body that produces swelling...
(water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
retention). These effects are related to the inhibition of cortisol
Cortisol
Cortisol is a steroid hormone, more specifically a glucocorticoid, produced by the adrenal gland. It is released in response to stress and a low level of blood glucocorticoids. Its primary functions are to increase blood sugar through gluconeogenesis; suppress the immune system; and aid in fat,...
metabolism within the kidney, and the subsequent stimulation of the mineralocorticoid
Mineralocorticoid
Mineralocorticoids are a class of steroid hormones characterised by their similarity to aldosterone and their influence on salt and water balances.-Physiology:...
receptors. Thus, consumption of black licorice can mimic disorders of excess aldosterone
Aldosterone
Aldosterone is a hormone that increases the reabsorption of sodium ions and water and the release of potassium in the collecting ducts and distal convoluted tubule of the kidneys' functional unit, the nephron. This increases blood volume and, therefore, increases blood pressure. Drugs that...
.
Glycyrrhizin and other licorice root products have been used for numerous medical purposes, in particular, treatment of peptic ulcer
Peptic ulcer
A peptic ulcer, also known as PUD or peptic ulcer disease, is the most common ulcer of an area of the gastrointestinal tract that is usually acidic and thus extremely painful. It is defined as mucosal erosions equal to or greater than 0.5 cm...
s and as an expectorant. The triterpene derivative of hydrolyzed
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
glycyrrhizin glycyrrhetinic acid
Glycyrrhetinic acid
Glycyrrhetinic acid is a pentacyclic triterpenoid derivative of the beta-amyrin type obtained from the hydrolysis of glycyrrhizic acid, which was obtained from the herb liquorice. It is used in flavoring and it masks the bitter taste of drugs like aloe and quinine. It is effective in the treatment...
is itself effective in treatment of peptic ulcer. According to MedlinePlus
MedlinePlus
MedlinePlus is a free Web site that provides consumer health information for patients, families, and Health care providers. The site brings together information from the United States National Library of Medicine, the National Institutes of Health , other U.S. government agencies, and...
and the Natural Medicines Comprehensive Database, licorice is "possibly effective" for dyspepsia
Dyspepsia
Dyspepsia , also known as upset stomach or indigestion, refers to a condition of impaired digestion. It is a medical condition characterized by chronic or recurrent pain in the upper abdomen, upper abdominal fullness and feeling full earlier than expected when eating...
in combination with other herbs, but there is "insufficient evidence" to rate its effectiveness for other conditions. Regarding stomach ulcers, specifically, there is "some evidence...that specially prepared licorice will speed the healing of stomach ulcers".
An un-blinded study of 82 patients from the early 1980s, published in the British Medical Journal
British Medical Journal
BMJ is a partially open-access peer-reviewed medical journal. Originally called the British Medical Journal, the title was officially shortened to BMJ in 1988. The journal is published by the BMJ Group, a wholly owned subsidiary of the British Medical Association...
, reported that Caved-S had a therapeutic effect is similar to that of cimetidine
Cimetidine
Cimetidine INN is a histamine H2-receptor antagonist that inhibits the production of acid in the stomach. It is largely used in the treatment of heartburn and peptic ulcers. It is marketed by GlaxoSmithKline under the trade name Tagamet...
in the treatment of gastric ulcers.
Although licorice may produce anti-inflammatory
Anti-inflammatory
Anti-inflammatory refers to the property of a substance or treatment that reduces inflammation. Anti-inflammatory drugs make up about half of analgesics, remedying pain by reducing inflammation as opposed to opioids, which affect the central nervous system....
effects, it is uncertain as to whether that is due to glycyrrhizin, glycyrrhetinic acid, or some other licorice derivative.
Researchers have recently demonstrated doses of licorice root extract, delivering the constituent glycyrrhizin in amounts similar to that contained in standard medical doses of the root, rapidly and significantly lowered levels of circulating testosterone
Testosterone
Testosterone is a steroid hormone from the androgen group and is found in mammals, reptiles, birds, and other vertebrates. In mammals, testosterone is primarily secreted in the testes of males and the ovaries of females, although small amounts are also secreted by the adrenal glands...
in males.
Glycyrrhizin inhibits liver cell injury caused by many chemicals and is used in the treatment of chronic hepatitis
Hepatitis
Hepatitis is a medical condition defined by the inflammation of the liver and characterized by the presence of inflammatory cells in the tissue of the organ. The name is from the Greek hepar , the root being hepat- , meaning liver, and suffix -itis, meaning "inflammation"...
and cirrhosis
Cirrhosis
Cirrhosis is a consequence of chronic liver disease characterized by replacement of liver tissue by fibrosis, scar tissue and regenerative nodules , leading to loss of liver function...
in Japan. It also inhibits the growth of several DNA and RNA viruses, inactivating herpes simplex
Herpes simplex
Herpes simplex is a viral disease caused by both Herpes simplex virus type 1 and type 2 . Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral herpes, the visible symptoms of which are colloquially called cold sores or fever...
virus particles irreversibly.