Glycyrrhetinic acid is a natural compound derived from the roots of the licorice plant, Glycyrrhiza glabra. This botanical extract has a long history of use in various traditional medicinal systems, including ancient Chinese, Egyptian, and Ayurvedic practices. It is a key bioactive component of licorice, garnering broad scientific interest for its potential health applications.
Key Biological Properties
Glycyrrhetinic acid exhibits anti-inflammatory effects. It can alleviate skin irritation, redness, and heat sensations. This action is partly attributed to its ability to modulate specific enzymes, such as 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which influences cortisol metabolism. By inhibiting this enzyme, glycyrrhetinic acid can increase local cortisol levels, contributing to its anti-inflammatory effects.
Glycyrrhetinic acid also displays antioxidant properties. It helps protect cellular components like DNA and proteins from damage caused by free radicals. This protective effect is achieved by stimulating antioxidant enzymes, such as heme oxygenase-1 (HO-1), and by inhibiting lipid peroxidation.
Glycyrrhetinic acid is recognized for its skin-soothing capabilities. It can diminish redness and alleviate itching, making it a beneficial ingredient for sensitive or atopic skin conditions. This soothing effect is linked to its ability to inhibit pro-inflammatory cytokines like TNF-α and interleukin-1α. It may also inhibit the production of leukotrienes, which are lipid mediators involved in immune and inflammatory responses.
Applications and Uses
Glycyrrhetinic acid finds widespread application, particularly in skincare formulations. Its anti-inflammatory and soothing attributes make it a frequent ingredient in products designed for sensitive, reactive, or acne-prone skin. It helps calm irritation and reduce redness associated with these conditions.
The compound is also incorporated into skincare for hyperpigmentation and uneven skin tone. Glycyrrhetinic acid can aid in diminishing dark spots by inhibiting tyrosinase, an enzyme involved in melanin production. While its brightening effect is a subject of ongoing discussion, it is often present in formulations targeting such concerns.
Beyond its cosmetic uses, glycyrrhetinic acid has traditional and modern medicinal applications. It is used in some topical preparations, and its parent compound, glycyrrhizic acid, is applied in anti-allergy and liver-supportive formulations. For instance, glycyrrhizic acid preparations are used as first-line drugs for liver diseases in China and Japan due to their anti-inflammatory and hepatoprotective effects.
Exploring Emerging Therapeutic Potential
Glycyrrhetinic acid is a subject of ongoing scientific inquiry for its potential in other therapeutic areas. Research explores its possible anticancer activities, with studies investigating its effects on various cancer cell lines, including gastric and breast cancer. These studies aim to understand how it might prevent cell proliferation or induce programmed cell death in cancer cells.
The compound also shows promise in antiviral research, with investigations into its effects against viruses. This includes herpes, hepatitis (such as B and C), and coronaviruses. While the precise mechanisms are still being elucidated, glycyrrhetinic acid and its derivatives are being studied for their ability to interfere with viral replication or entry into host cells.
Preliminary studies also suggest antiparasitic activities. It is important to remember that these areas represent ongoing research, and glycyrrhetinic acid is not yet an established treatment for these conditions. Continued studies are working to understand the molecular structures and mechanisms that underpin these effects.
Safety and Important Considerations
While glycyrrhetinic acid offers benefits, particularly in topical applications, important safety considerations exist, especially with oral intake or high doses. One effect is its potential to cause hypertension (high blood pressure). This occurs because the compound can inhibit the enzyme 11β-hydroxysteroid dehydrogenase type 2, which normally converts active cortisol into an inactive form. Elevated cortisol levels can lead to sodium retention and potassium excretion, contributing to increased blood pressure.
This mechanism can also result in hypokalemia (low blood potassium). Symptoms of hypokalemia can include muscle weakness, cramps, and fatigue. Fluid retention (edema) is another potential side effect, manifesting as swelling, especially in the lower extremities, due to increased sodium and water retention.
Individuals with pre-existing conditions like hypertension, cardiovascular diseases, or kidney disease should exercise caution with products containing glycyrrhetinic acid, especially at higher oral doses. The inhibitory effect on 11β-hydroxysteroid dehydrogenase is reversible, but the physiological changes, such as suppression of the renin-angiotensin system, may persist for several months after discontinuing use. Consulting healthcare professionals is advisable for internal use to ensure proper guidance and monitoring.