PRELIMINARY-STUDY OF THE POTENTIAL VASODILATOR EFFECTS ON RAT AORTA OF CENTAUREIN AND CENTAUREIDIN, 2 FLAVONOIDS FROM CENTAUREA-CORCUBIONENSIS

In this work, the potential vasorelaxant activity of centaurein and ce ntaureidin, two flavonoids from Centaureo corcubionensis, were studied for the first time in rat aorta. Centaureidin (10 mu M-0.1 mM) totall y relaxed, in a concentration-dependent manner and with almost equal e ffectiveness, the contractions induced by NA (IC50 = 16.7 +/- 1.9 mu M ) or by a high K+ concentration (IC50 = 16.1 +/- 3.1 mu M) in intact r at aortic rings. Mechanical removal of endothelium did not significant ly modify the vasoralexant effects of this flavone (IC50 = 20.8 +/- 2. 4 mu M for NA; IC50 = 21 +/- 2.9 mu M for K+). On the other hand, cent aurein (1 mu M-0.1 mM) had no effect on NA-and high K+-induced contrac tions in rubbed and intact rat aortic rings. These results indicate th at substitution by glucose in the chemical structure of centaureidin l eads to the loss of its vasodilator activity.