Abstract
Glycyrrhetinic acid and fifteen derivatives of glycyrrhetinic acid including glycyrrhizin were examined to determine whether they inhibit the lipoxygenase and the cyclooxygenase activities of cloned mastocytoma cells. These compounds were more effective in inhibiting the lipoxygenase than the cyclooxygenase. Of these compounds, the disodium salt of olean-12-ene-3β, 30-diol 3β, 30-di-O-hemiphthalate inhibited 5-lipoxygenase most strongly (ID50, 5.8×10-6 M), whereas the half-inhibition dose for the cyclooxygenase was 5.6×10-5 M. Glycyrrhetinic acid, the aglycone of glycyrrhizin, slightly inhibited the lipoxygenase and the cyclooxygenase at a concentration of 10-4 M but had little effect at 10-5 M. Glycyrrhizin and carbenoxolon sodium showed no detectable inhibition of either enzyme at less than 10-4 M.
