by Jeanette Jacknin, M.D.
Licorice, or Glycyrrhiza glabra, gets its name from the Greek words glyks, meaning sweet, and rhiza, meaning root. It is the sweet tasting rhizomes and roots that are used as flavorings. Ancient Chinese herbalists distilled the root’s essence and prescribed it for a wide range of conditions. It was known to the Greeks, Egyptians and Romans. Licorice was cultivated in England since the 16th century by Dominican monks in Yorkshire for its use in confectionery.
Licorice grows wild throughout Southeastern Europe, the Middle East and Asia. It is a tall erect legume, standing up to 5 feet tall, with the root descending about 3 feet underground. The plant bears small spikes of lilac-colored flowers with bean-like pods, which contain three or four seeds. The dried roots are brown on the outside, yellow on the inside, very hard and fibrous and about three-eighths of an inch in diameter. Licorice is also available as a powder and as solid sticks of glossy black, sweet concentrated essence.
Licorice helps support the adrenal gland, cleanse the colon and support lung health. It is a common ingredient in throat-soothing herbal supplements. Herbal preparations containing licorice are used to treat stomach and intestinal ulcers, lower acid levels and coat the stomach wall with a protective gel. Its natural sweetness makes it a favorite flavor in herbal teas as a mild laxative, a diuretic and for flatulence. It has also been known to relieve rheumatism and arthritis, night sweats and to regulate low blood sugar. Licorice extract produces mild estrogenic effects, and has also proven useful in treating symptoms of menopause, regulating menstruation and relieving menstrual cramps.1
There are risks of mild to severe side effects when licorice root is taken orally in large amounts or for long periods of time. Pregnant and breastfeeding mothers should not take licorice orally, as some research has indicated the increased risk of premature birth.2 Licorice in large or chronic doses may also be harmful for people who have diabetes or kidney disease. Large quantities of licorice can increase hypertension and excitability as well.3
Almost 8 percent of the licorice plant is composed of a glycoside called glycyrrhizin. Glycyrrhizin reduces the activity of two enzymes that break down prostaglandin E (PGE). By inhibiting the body's disposal of PGE, glycyrrhizin allows more PGE to circulate in the body, which is believed to promote the production of stomach mucus. This decreases the production of painful and potentially dangerous stomach acids that lead to many stomach conditions, and thus helping to protect the stomach tissue. In in vivo studies, the flavonoids of the licorice plant have been shown to kill Helicobacter pylori, the bacteria responsible for causing most ulcers and stomach inflammation. Glycyrrhizin also promotes the production of mucus in the respiratory tract, making the respiratory tract mucus less sticky and aiding in its removal from the body. This explains how licorice is helpful with severe respiratory conditions such as bronchitis.
Licorice has also been used in Traditional Chinese Medicine (TCM) to treat conditions ranging from diabetes to tuberculosis. The two major constituents of licorice, glycyrrhizin and flavonoids, also exhibit anti-inflammatory effects and inhibit the breakdown of the cortisol. Licorice may also have antiviral properties, although this has not yet been proven in human pharmacological studies.
Licorice extract is considered one of the many natural compounds that act as a skin brightener when applied topically.4 An extract of licorice, called liquiritin, has been used in connection with melasma, a hyperpigmentation disorder of the skin, usually in women.5 The main active ingredient found in licorice extract for skin bleaching is glabridin. Glabridin inhibits pigmentation by preventing tyrosinase activation. It is nontoxic to melanocytes and to surrounding keratinocytes, preventing permanent discoloration of the skin. Licorice is also an excellent choice in the treatment of post-inflammatory hyperpigmentation and melasma in skin of color, as it is mild as well as being an effective brightener and bleach.6
Licorice extract has also long been thought to have anti-inflammatory properties. A few years back, researchers found Licochalcone A from licorice extract exhibited a potent anti-inflammatory action on a broad range of skin cells involved in skin inflammation.7,8 Glycyrrhizinic acid from licorice has been shown to improve dermatitis, an inflammatory condition. In a Iranian study, 2 percent glycyrrhizinic acid gel applied topically significantly decreased the erythema, edema and itching of the skin in the study’s subjects during the two-week treatment period.9
Licorice root with Licochalone A applied topically, will both soothe the skin and inhibit the production of irritants, which contribute to skin conditions such as acne and rosacea.10 According to Beiersdorf, which makes Eucerin’s Redness Relief line, Licochalcone A has been shown to have antibacterial , anti-parasitic and anti-inflammatory properties.11 Beiersdorf ‘s study clearly demonstrated Licochalcone A is a potent inhibitor of the pro-inflammatory in vitro responses of a variety of dermatologically relevant cell types. Based on Beiersdorf’s data, one anti-inflammatory mode of action of Licochalcone A might be dual inhibition of cyclooxygenase and lipoxygenase.12 Beiersdoft evaluated the efficacy of their skin care regimen containing Licochalcone A in 62 patients with mild to moderate red facial skin who used the four-product Eucerin skin care regimen for eight weeks. Clinical evaluations, subject response and photography confirmed very good tolerability of the regimen and significant improvements in average erythema scores of the skin were observed at four and eight weeks.13
From skin brightening to acne and rosacea, Licorice root has a promising role in skin health, and the research behind it is continuously confirming its significance as an active ingredient in skin care lines.
Jeanette Jacknin, M.D., (JJMDSkinCare.com and DrJacknin.com) is a board-certified dermatologist. She is a well-respected physician, entrepreneur and author with a passion for nutricosmeceuticals and holistic dermatology. Dr. Jacknin’s is the author of, “Smart Medicine for Your Skin”, published by Penguin Putnam. She is available for consultation. Contact her at [email protected] .
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