ABSTRACT
The root of Glycyrrhiza glabra, liquorice, has been used as a medicine for many years. However, it is also the source of carbenoxolone, a medicine previously used for oesophageal, stomach and mouth ulcers. Liquorice root extract is a complex mixture of chemicals of which the more important are flavonoids, coumarins and especially certain terpenes, most notably the saponin glycosides, glycyrrhizin and glycyrrhizic acid, which are readily released from it after ingestion. The role of liquorice for the treatment of peptic ulcer was thought at first to be due to its effect on the protective quality of the mucus lining the stomach making it more resistant to the hydrochloric acid produced in the stomach for digesting food. Chemically glycyrrhizic acid is a steroid which is converted after ingestion by hydrolysis to glycyrrhetinic acid. Carbenoxolone is a hemisuccinate derivative of glycyrrhetinic acid, with a steroid-like structure, that was used for gastric, duodenal and oesophageal ulcers in the last century.
