Glycyrrhiza glabra and its wonderful Properties
Licorice (Glycyrrhiza glabra, Glycyrrhiza uralensis): The medicinally used part of licorice is the root and dried rhizome of the plant. Licorice is widely used in the Indian system of medicine. Licorice root has been used as a dietary supplement for stomach ulcers, bronchitis, and sore throat, as well as infections caused by viruses, such as hepatitis. Most licorice nowadays is produced in Greece, Turkey, and Asia. Licorice extracts are purported to be active as anti-allergic, anti-inflammatory, spasmolytic, mild laxative, antistress, antidepressive, antiulcer, liver protective, estrogenic, emmenagogue (herbs which stimulate blood flow in the pelvic area and uterus), and antidiabetic substances. Clinical trials have found that glycyrrhizin might reduce complications from hepatitis C in some patients. However, there is not enough evidence to confirm that glycyrrhizin has this effect. There are insufficient clinical data to establish whether licorice is effective for stomach ulcers.
The major bioactive constituent is glycyrrhizin (or glycyrrhizic acid). However, chronic licorice consumption can lead to serious side effects due to the presence of considerable quantities of glycyrrhizin, which causes severe hypokalaemia and hypertension. Licorice root supplements are available as capsules, tablets, or liquid extracts. Because of the toxicity of glycyrrhizin some licorice supplements are prepared with the glycyrrhizin removed. These products are referred to as deglycyrrhizinated licorice (DGL).
Although licorice extracts are known to exhibit anti-cancer activities, the potential side-effects of chronic licorice consumption, due to the presence of glycyrrhizin, make this dietary supplement unacceptable as an adjunct to therapy. Studies using a hexane-ethanol extract of licorice, which lacks glycyrrhizin, demonstrated a reduction in the metastatic characteristics of human prostate cancer cells in culture. The active compound in this hexane-ethanol extraction of licorice was shown to be licoricidin. The treatment of these cancer cells with licoricidin induced a reduction in cell migration and the secretion of matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase (TIMP-1), urokinase-type plasminogen activator and vascular endothelial growth factor (VEGF), as well as in the expression of adhesion molecules. These results indicate that licoricidin is a potent anti-metastatic agent, which can markedly inhibit the metastatic and invasive capacity of malignant prostate cancer cells.
The potential for licorice extracts to be used as adjuncts in the treatment of type 2 diabetes was demonstrated when it was shown that compounds in the extracts can activate peroxisome proliferator-activated receptor-gamma (PPARγ). PPARγ is the target of the thiazolidinedione (TZD) class of type 2 diabetes drugs (for more information of the action of the TZDs see The Medical Biochemistry Page). Characterization of the alcohol extraction products from licorice found that at least 39 different phenolic compounds can identified.