Carbenoxolone

Carbenoxolone, a synthetic derivative of glycyrrhizinic acid, is a licensed drug (in the UK) for oesophageal ulceration and inflammation. Other uses include treatment of oral and perioral lesions.

Carbenoxolone (aka Carbenoxylone, CBX) is also finding increasing use as a Connexon (a hemichannel made up of 6 connexin subunits) blocker and as a Gap Junction (2 connexons join together) blocker.

Carbenoxolone has also been investigated for nootropic effects (PMID 15071189). This research started from an observation that long-term exposure to glucocorticoids may have negative effects on cognition. Carbenoxolone may decrease the amount of active glucocortocoid in the brain, because the drug inhibits 11Beta-hydroxysteroid dehydrogenase type 1, an enzyme which activates cortisol into cortisone, a glucocorticoid. In the research trial investigating this use of carbenoloxone, it was shown that the drug improved verbal fluency in elderly healthy men (aged 55-75). In type 2 diabetics aged 52-70, the drug improved verbal memory. However, it should be noted that potassium-sparing diuretic amiloride was co-administered with carbenoxolone, since carbenoxolone used by itself may cause hypertension by increasing cortisol in the kidneys.

Carbenoxolon