Glycyrrhetinic Acid (GA)

Glycyrrhetinic acid is a pentacyclic triterpenoid derivative of the beta-amyrin type obtained from the hydrolysis of glycyrrhizic acid, which was obtained from the herb liquorice. It is used in flavoring and it masks the bitter taste of drugs like aloe and quinine. It is effective in the treatment of peptic ulcer and also has expectorant (antitussive) properties. Glycyrrhetinic acid inhibits the enzymes that metabolize the prostaglandins PGE-2 and PGF-2α to their respective 15-keto-13,14-dihydro metabolites which are inactive. This causes an increased level of prostaglandins in the digestive system. Prostaglandins inhibit gastric secretion but stimulate pancreatic secretion and mucous secretion in the intestines and markedly increase intestinal motility. They also cause cell proliferation in the stomach. The effect on gastric acid secretion, promotion of mucous secretion and cell proliferation shows why licorice has potential in treating peptic ulcer.