Inhibition of peptic activity by carbenoxolone and glycyrrhetinic acid. Gut 11, 344–351. doi: 10.1136/gut.11.4.344

SUMMARY Carbenoxolone (Biogastrone, Berk) has been shown to reduce the peptic activity and total acidity of gastric juice obtained from anaesthetized pylorus-ligated rats without affecting significantly the volume of gastric juice secreted or the K+ concentration. Glycyr-rhetinic acid was less potent in reducing peptic activity and caused no reduction in total acidity. Antipeptic activity of carbenoxolone has also been demonstrated in vitro using the pepsin plate technique and the haemoglobin pepsin assay. It is suggested that these actions of carbenoxolone may contribute to the increased rate of healing of peptic ulcer in patients treated with the drug. Liquorice extract has been used in the treatment of peptic ulcers for centuries without any parti-cular rationale. Its activity is believed to be associated with the glycoside, glycyrrhizinic acid, hydrolysis of which yields glycyrrhetinic acid (1) [3,hydroxy-1 1-oxo-18/8olean-12-en-30-oic acid]. Carbenoxolone sodium (2) is the disodium salt of glycyrrhetinic acid hemisuccinate, and 'Present address: Department of Pharmacology & Therapeutics, University of Dundee, DDI 4HN is marketed as Biogastrone (Berk). It is claimed to be of value in the treatment of gastric ulcer but is of little value in the treatment of duodenal ulcer. Several clinical trials have been reported in recent years on the efficacy of carbenoxolone in gastric ulcer therapy. For instance Doll, Hill