Introduction

Glycyrrhizin is a substance found in liquorice (alt. licorice) root that functions as a sweetener (30 to 50 times as sweet as sucrose)and is also categorized as a glycoside. . However, the taste of glycyrrhizin "overrides" its sweetness, thus giving it a distinct flavor and different sweetness than sugar. The sweetness of glycyrrhizin lingers in the mouth for some time as well. Glycyrrhizin gives liquorice its characteristic flavor. This makes gycyrrhizin unsuitable as a sugar substitute, but an ideal flavoring for dishes. In the industrial setting, glycyrrhizin is used as a flavoring in candies, pharmaceuticals, tobacco products and foods.

Glycyrrhizin is chemically known as a triterpenoid saponin glycoside. In general, glycosides are chemicals composed of a sugar attached to a non-sugar molecule. There are many types of glycosides in nature, with many different properties (e.g., medicinal).

Glycyrrhizin is broken down in the body by hydrolysis. Hydrolysis is the breaking down of a chemical compound into two or more simpler compounds by reacting with water. For example, proteins, fats, and complex carbohydrates in food are broken down in the body by hydrolysis that is catalyzed by enzymes in the digestive tract. Hydrolysis of glycyrrhizin yields the aglycone called glucuronic acid.

The EU (European Union) suggests that one should not consume more than 100mg of glycyrrhizic acid per day. This amount equates to roughly 50 g liquorice sweets. Remember that 30 grams is approximately 1 ounce (1/16 of a pound). In Japan, the government recommendation is twice that (200mg) of the EU.

Pharmacological effects

The products of glycyrrhizin hydrolysis (glycyrrhetinic acid) may be helpful in the treatment of peptic ulcers, since they cause mucus production in the digestive tract and thickening of tissues. They also interfere with prostaglandins and hence, can help peptic ulcers heal. Glycyrrhizin acts in a similar manner to cortisone. This can have both positive and hegative attributes. Since glycerrhizin mimics cortisol, it will have slight to moderate anti-inflammatory effects. However, since glycyrrhizin is exogenously introduced (consumed), and therefore, not regulated in comparison to the adrenal glands, which are regulated, cortisol-like effects of excess glycyrrhizin can cause hypertension and edema (water retention). The presence of glycyrrhizin suppresses cortisol metabolism within the kidney, and the subsequent stimulation of the mineralocorticoid receptors, mimicking hyper-aldosteronism.

Glycyrrhizin and licorice root products have been used over the ages for various medical purposes. Some of the medicinal benefits of the glycyrrhizin in licorice are
1) treatment of peptic ulcers (glycyrrhetinic acid, the derivative of glycyrrhizin after hydrolysis helps peptic ulcer) and
2) as an expectorant (expelling mucus) in the treatment of coughs.

Although licorice may produce anti-inflammatory effects, it is uncertain whether that is due to glycyrrhizin, glycyrrhetinic acid, or some other licorice derivative.

Glycyrrhizin has protective functions against hepatic cell (liver cell) injury caused by chemical damage (e.g., alcohol). Thus, glycyrrhizin can be beneficial during reactivations of chronic hepatitis (e.g., Hep B, C). Glycyrrhizin can lowered levels of circulating testosterone in males. Whether this is beneficial or detrimental, depends on the reason for the use of glycyrrhizin in this capacity. Glycyrrhizin also interferes with the production of a few DNA and RNA viruses such as herpes simplex. Herpes simplex viral particles are inactivated by glycyrrhizin and this may have positive implications for the treatment of cold sores, and other infection manifestations.