Licorice

Common name: Licorice
Other names: Liquorice, sweet root, Persian licorice, Chinese licorice, Spanish licorice
Latin name: Glycyrrhiza glabra
Affinities: Digestive system, immune system, respiratory system, endocrine system
Actions: Expectorant, demulcent, adaptogen, antispasmodic, mild laxative, carminative, diaphoretic, immunomodulator, hepatoprotective
Specific indications: Dry or spasmodic cough, red hot inflamed tissues, constipation
Diseases: Catarrh(3), bronchitis(3), Addison’s disease(3), peptic ulcers(2), gastritis(3), abdominal colic(3), obesity(1), rheumatoid arthritis(2), lupus(2), allergies(2), scleroderma(2), allergies(2), IBD(2), Hepatitis C(2)
Parts used: Dried root
Energetics: Warming, moistening

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Characteristics: Licorice is a shrub that grows 4 to 5 inches in height and is cultivated in Turkey, Spain, China, and Pakistan (Kuhn and Winston, 2000). The latin name glycyrrhiza means ‘sweet root’ and refers to the yellow root that is very sweet in taste. Chinese licorice has pale yellow flowers.

History: Licorice is found in the first great Chinese herbal text, the Pen Tsao Ching, that is thought to have been written by Shen Nung around 3000 B.C (Castleman, 2001). In TCM, licorice is known as the ‘great harmonizer’, meaning it is believed the herb helps other herbs work well together. Licorice also has an ancient history of use in Western herbalism. In the 3rd century B.C., the ancient Greek botanist Theophrastus in his text, Enquiry into Plants, stated the roots that grow in Scythia (Asia minor) are sweet and useful for people with dry coughs and respiratory illness (Winston, 2007). During the 3rd century B.C. Hippocrates recommended licorice for coughs, asthma, and respiratory complaints (Castleman, 2001). He named it sweet root which is, ‘glukos riza’, in Greek which evolved into the herb’s genus name, glycyrrhiza. The 1st century Roman herbalist Pliny used the herb as an expectorant and digestive soother.

The 12th century German abbess Hildegard of Bingen used the herb for stomach problems (Castleman, 2001). It was subsequently mentioned in herbal texts in the 14th and 15th centuries as a cough and respiratory remedy. The 17th century English herbalist, Nicholas Culpeper used the herb in similar ways, writing of it in his herbal, ‘(licorice) is under the dominion of Mercury. Liquorice boiled in fair water, with some Maiden-hair and figs, makes a good drink for those that have a dry cough or hoarseness, wheezing or shortness of breath’ (Culpeper, 1814). The Native Americans used American licorice as a cough remedy, laxative, and earache treatment (Castleman, 2001).

The 19th century Eclectics in America used licorice as in the Eclectic text King’s American Dispensatory, it is written, ‘(licorice root) acts upon mucous surfaces, lessening irritation, and is consequently useful in coughs, catarrhs, irritation of the urinary organs, and pain of the intestines in diarrhoea’ (Felter and Lloyd, 1898).

Current applications: Licorice is an adaptogenic herb that likely effects the adrenals, but also has an affinity for the digestive and respiratory systems and modulates the immune system. In Holistic Herbal, David Hoffman remarks that licorice is one of a group of plants that has a marked effect on the endocrine system (Hoffman, 1988). He explains this is why licorice has a beneficial effect on the disorders of the adrenal glands such as Addison’s disease. He also mentions it may have use in treating catarrh, bronchitis, coughs, Addison’s disease, peptic ulcers, gastritis, abdominal colic.

In The School of Natural Healing, Dr. Christopher mentions that licorice softens, soothes, lubricates, and nourishes the intestinal tract. He also states licorice is one of the oldest, mildest and yet most efficient laxatives, recommending it even for constipated children and older people unable to take stronger laxatives (Christopher, 1976). David Winston in Adaptogens: Herbs for Strength, Stamina, and Stress Relief, states licorice, as an immunomodulatory herb, has applications in treating rheumatoid arthritis, lupus, allergies, scleroderma, and allergies (Winston, 2007). He mentions it can be of benefit for those people with inflammatory bowel conditions.

Science: Licorice has been well studied ex vivo or in vivo using experimental models. Licorice root extracts have been found to reduce airway inflammation in mouse models in agreement with its traditional role as demulcent herb (Xie et al., 2009). It has immunomodulatory activity as it has also been found to boost immune function in one study (Brush et al., 2006). In a remarkable experiment, licorice root extracts were found to inhibit the binding of h. pylori to human gastric mucosa showing how the traditional use of licorice to treat peptic ulcers in humans may be justified (Wittschier et al., 2009). Another experiment found licorice extracts exhibited memory and learning enhancing effects in mice (Dhingra et al., 2004). These results, although not in humans, highlight how broad the medicinal potential of licorice is.

A human study that examined obesity found that over 8 weeks licorice flavonoid oil significantly reduced total body fat and LDL cholesterol in overweight individuals compared with the placebo (Tominaga et al., 2009). In Japan, a compound called glycyrrhizin that is extracted from licorice roots is widely used for chronic hepatitis C, it reportedly reduces the progression of liver disease to hepatocellular carcinoma (Rossum et al., 1999).

Safety: Moderate-high, but it should be avoided when the person has cardiovascular disease or high blood pressure. It is best to use smaller doses or doses for short periods of time. Avoid use during pregnancy.

Dosage: 5-45 drops of tincture may be taken 2-3 times daily.

Scientific Summary

Research on models

Anti-inflammatory: In one study, licorice root flavonoids were found to reduce lipopolysaccharide induced acute pulmonary (lung) inflammation in mice (Xie et al., 2009).

Anti-cancer and estrogenic activity: In one study, glabridin, the major isoflavan in licorice root, displayed estrogenic and anti-cancer activity on human breast cancer cells (Tamir et al., 2000).

Immune stimulating activity: In a study, licorice alongside astragalus and echinacea, were shown to activate human immune cells (Brush et al., 2006). The authors also observed an additive effect of these herbs together on immune activation.

Neuroprotective activity: In one study, licorice was found to increase learning and memory in mice that were fed orally for 7 days (Dhingra et al., 2004).

Anti-microbial properties: In a study, licorice root extracts were found to inhibit adhesion of H. pylori to human gastric mucosa (Wittschier et al., 2009). Hence showing potential for treating stomach ulcers.

Research on humans

Obesity: In a study (n = 84, double blind placebo controlled) found that over 8 weeks licorice flavonoid oil significantly reduced total body fat and LDL cholesterol in overweight individuals compared with the placebo only group (Tominaga et al., 2009). No significant adverse events were observed.

Hepatitis C: In one study (n = 57, double blind placebo controlled) found that glycyrrhizin extracted from licorice roots (Rossum et al., 1999), up to 240 mg thrice weekly, lowered serum alanine aminotransferase during treatment.

References:

Brush, Julie, et al. “The effect of Echinacea purpurea, Astragalus membranaceus and Glycyrrhiza glabra on CD69 expression and immune cell activation in humans.” Phytotherapy Research 20.8 (2006): 687-695.

Castleman, Michael. “The new healing herbs.” Bantam Book, New York (2001): 465-471.

Christopher, John R. School of Natural Healing. Christopher Publications, 1976.

Culpeper, Nicholas. “Culpeper’s complete herbal.” (1814).

Dhingra, Dinesh, Milind Parle, and S. K. Kulkarni. “Memory enhancing activity of Glycyrrhiza glabra in mice.” Journal of ethnopharmacology 91.2 (2004): 361-365.

Felter, Harvey and Lloyd, John. King’s American Dispensatory, 1898.

Hoffman, David. Holistic herbal. Element Books, 1988.

Kuhn, Merrily A., and David Winston. Herbal therapy and supplements: a scientific and traditional approach. Lippincott Williams & Wilkins, 2000.

Rossum, Tekla Gj Van, et al. “Intravenous glycyrrhizin for the treatment of chronic hepatitis C: a double‐blind, randomized, placebo‐controlled phase I/II trial.” Journal of gastroenterology and hepatology 14.11 (1999): 1093-1099.

Tamir, Snait, et al. “Estrogenic and antiproliferative properties of glabridin from licorice in human breast cancer cells.” Cancer research 60.20 (2000): 5704-5709.

Tominaga, Yuji, et al. “Licorice flavonoid oil reduces total body fat and visceral fat in overweight subjects: A randomized, double-blind, placebo-controlled study.” Obesity Research & Clinical Practice 3.3 (2009): 169-178.

Winston, David, and Steven Maimes. Adaptogens: herbs for strength, stamina, and stress relief. Inner Traditions/Bear & Co, 2007.

Wittschier, Nicole, Gerhard Faller, and A. Hensel. “Aqueous extracts and polysaccharides from liquorice roots (Glycyrrhiza glabra L.) inhibit adhesion of Helicobacter pylori to human gastric mucosa.” Journal of ethnopharmacology 125.2 (2009): 218-223.

Xie, Yi-Cheng, et al. “Inhibitory effects of flavonoids extracted from licorice on lipopolysaccharide-induced acute pulmonary inflammation in mice.” International immunopharmacology 9.2 (2009): 194-200.