Licorice and enzymes other than 11 beta-hydroxysteroid dehydrogenase: an evolutionary perspective.
Licorice has long been known to promote the healing of ulcers. In the 1950s, studies with licorice-derived compounds revealed that the anti-ulcer effects of licorice are due to inhibition of 15-hydroxyprostaglandin dehydrogenase and delta 13-prostaglandin reductase. 15-Hydroxyprostaglandin dehydrogenase converts prostaglandins E2 and F2 alpha to 15-ketoprostaglandins, which are inactive. delta 13-Prostaglandin reductase metabolizes the inactive delta 13-prostaglandin to 13,14-dihydro,15-ketoprostaglandin, which is further metabolized and excreted in urine. Thus, licorice-derived compounds have the effect of raising the local concentration of prostaglandins that promote mucous secretion and cell proliferation in the stomach, leading to healing of ulcers. 11 beta-Hydroxysteroid dehydrogenase, which also is inhibited by licorice-derived compounds, shares a common ancestor with 15-hydroxyprostaglandin dehydrogenase. Both enzymes are homologous to Streptomyces hydrogenans 3 alpha,20 beta-hydroxysteroid dehydrogenase, which also is inhibited by licorice. Thus, licorice inhibits enzymes that diverged at least 2 billion years ago from a common ancestor. Other oxidoreductases in bacteria, plants, and animals that are inhibited by licorice-derived compounds are likely to be discovered in the future.
Baker
M E
ME
Department of Medicine, University of California, San Diego, La Jolla 92093-0623.
D042842:11-beta-Hydroxysteroid Dehydrogenases; D000818:Animals; D000897:Anti-Ulcer Agents / Q000494:pharmacology*; D005075:Biological Evolution; D003349:Cortisone Reductase / Q000037:antagonists & inhibitors; D006035:Glycyrrhiza; D006801:Humans; D006911:Hydroxyprostaglandin Dehydrogenases / Q000037:antagonists & inhibitors; D006913:Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors*; D010946:Plants, Medicinal; D013291:Streptococcus / Q000201:enzymology
D000897:Anti-Ulcer Agents; D006913:Hydroxysteroid Dehydrogenases; D006911:Hydroxyprostaglandin Dehydrogenases; C035859:15-hydroxyprostaglandin dehydrogenase; D042842:11-beta-Hydroxysteroid Dehydrogenases; D003349:Cortisone Reductase