What to know about Glycyrrhiza glabra (licorice) before using it medicinally

Glycyrrhiza glabra, commonly known as licorice, is a plant-based remedy that has been extensively studied for its potential health benefits, including its anti-inflammatory and antimicrobial properties, which can aid in the management of digestive issues and respiratory problems.

As a horticultural crop, Glycyrrhiza glabra is known for its unique cultivation requirements, including a preference for well-drained soil and full sun exposure, and is often grown in regions with warm, dry climates. Botanically, Glycyrrhiza glabra belongs to the Fabaceae family and is characterized by its distinctive, star-shaped flowers and long, thin roots.

Historically, the herb has been referenced in ancient Greek and Chinese medicine, with the Greek physician Dioscorides and the Chinese pharmacopeia both citing its medicinal properties.

This article explains the medicinal, horticultural, botanical, and historical aspects of Glycyrrhiza glabra.

What are the medicinal properties of Glycyrrhiza glabra?

Glycyrrhiza glabra helps with digestion, reducing inflammation, and soothing respiratory issues, such as coughs and bronchitis. Its demulcent properties also make it useful for skin conditions, like eczema and ulcers. Its anti-viral properties also treat infections.

Glycyrrhizin, flavonoids, and isoflavones are the active constituents responsible for the medicinal properties of licorice. Glycyrrhizin is a triterpenoid saponin that has anti-inflammatory and anti-oxidant effects. Flavonoids, such as quercetin, have anti-inflammatory and anti-bacterial properties. Isoflavones also have estrogenic activity.

The roots and rhizomes of Glycyrrhiza glabra are primarily used for medicinal purposes, although the leaves and stems are sometimes used as well. The roots contain the highest concentration of glycyrrhizin, which is the active constituent responsible for most of the plant's medicinal properties. The roots can be dried and powdered or made into decoctions.

Prolonged or excessive consumption of Glycyrrhiza glabra can lead to side effects such as water retention, potassium depletion, and high blood pressure. This is due to the plant's ability to inhibit the production of aldosterone, a hormone that regulates water and electrolyte balance. This is particularly concerning for people with pre-existing conditions such as kidney disease or hypertension.

Precautions when using Glycyrrhiza glabra medicinally include avoiding excessive consumption and combining it with other medications that have a diuretic effect. It is also contraindicated in pregnancy and lactation due to the potential for fetal or infant harm. Additionally, individuals with kidney or liver disease should use it with caution and under medical supervision.

What are the horticulural aspects of Glycyrrhiza glabra?

Glycyrrhiza glabra grow in well-drained soil and full sun to partial shade. The optimal temperature range for growth is 18-25°C (64-77°F), and it thrives in alkaline to neutral soil pH (7.0-8.5). Adequate moisture is essential, but the plant is relatively drought-tolerant.

For optimal growth, plant Glycyrrhiza glabra in areas with low competition and minimal shade. Plant spacing should be 0.5-1 meter (1.6-3.3 feet) apart. Soil preparation involves mixing in 2-3 inches of compost or well-rotted manure to improve soil fertility. Plant roots 10-15 cm (4-6 inches) deep in the spring or fall.

Harvesting Glycyrrhiza glabra typically occurs after 3-4 years, when the roots reach a diameter of 10-15 cm (4-6 inches). Roots are usually harvested in the autumn or winter when the plant is dormant. Harvesting too early can reduce root quality and quantity, while delayed harvesting may lead to reduced root mass.

Pests commonly affecting Glycyrrhiza glabra include aphids, whiteflies, and spider mites. Diseases include root rot caused by Phytophthora and Pythium, leaf spot caused by Cercospora, and powdery mildew caused by Erysiphe. Regular monitoring and use of integrated pest management strategies are recommended to mitigate these issues.

What are the botanical aspects of Glycyrrhiza glabra?

Glycyrrhiza glabra is a perennial legume with a woody root system, glabrous stems, and pinnate leaves with 9-17 leaflets. The plant can grow up to 1.5 meters tall, with a spread of 1-2 meters. The roots are thick and fleshy, with a characteristic sweet and bitter taste.

Glycyrrhiza glabra is classified in the kingdom Plantae, division Magnoliophyta, class Magnoliopsida, order Fabales, family Fabaceae, and genus Glycyrrhiza. The plant is also known as Glycyrrhiza echinata and has several synonyms, including Glycyrrhiza uralensis and Glycyrrhiza yunnanensis.

Several variants of Glycyrrhiza glabra exist, including the Chinese licorice (Glycyrrhiza uralensis) and the American licorice (Glycyrrhiza lepidota). Other variants include the Iranian licorice (Glycyrrhiza glabra var. glandulifera) and the Indian licorice (Glycyrrhiza glabra var. glandulosa).

Glycyrrhiza glabra is native to Southern Europe, Western Asia, and North Africa, but has been naturalized in many other regions. It is cultivated in many parts of the world, including India, China, and the Middle East, where it is considered a valuable medicinal plant.

The life cycle of Glycyrrhiza glabra typically takes 3-5 years to complete. The plant produces small yellow flowers in late spring, which are followed by pods containing 2-3 seeds each. The seeds germinate in autumn, and the new plants grow and mature during the next year.

What are the historical aspects of Glycyrrhiza glabra?

Glycyrrhiza glabra is an ancient plant with a rich history of use in traditional medicine and cooking. The plant's roots have been used for over 4,000 years in ancient civilizations, including Egypt, China, and Greece, for its sweet flavor and medicinal properties.

In ancient Greek mythology, Glycyrrhiza glabra was associated with the god Dionysus, who was said to have given the plant to the goddess Hera as a gift. In Roman mythology, the plant was associated with the goddess Venus, who was said to have used it to sweeten her wine. The plant's roots were also used in traditional Chinese medicine to treat various ailments.

In many cultures, Glycyrrhiza glabra is associated with sweetness, love, and fidelity. In ancient Greece, the plant was used as a symbol of marital love and fidelity, and it was often given as a gift to newlyweds. In India, the plant is considered sacred and is used in traditional rituals to promote love and fertility.

Historical texts, such as the Ebers Papyrus and the Materia Medica, provide evidence of the plant's use in ancient medicine. The Ebers Papyrus, which dates back to around 1550 BCE, contains recipes for licorice-infused remedies for various ailments. The Materia Medica, written by the ancient Greek physician Dioscorides, describes the plant's medicinal properties and uses.

Archaeological finds, such as ancient pottery and artifacts from ancient civilizations, demonstrate the widespread use of Glycyrrhiza glabra in ancient times. For example, a 2,000-year-old Greek wine amphora was discovered with a residue of licorice extract on its interior, suggesting that the plant was used to sweeten wine.