Inhibition of prostaglandin biosynthesis by the constituents of medicinal plants.

Abstract
Hot aqueous extracts of medicinal plants used in oriental medicine were tested for inhibitory effect on prostagladin biosynthesis in order to detect biologically active compounds present therein. Of 162 samples tested, 35 showed significant inhibition. Inhibitors of prostaglandin biosynthesis contained in Cyperus rotundus were identified as sesquiterpenes. .alpha.-Cyperone, the main inhibitor of C. rotundus, showed competitive-type inhibition with respect to the substrate, arachidonic acid.