Isolation of Vasodilatory Active Flavonoids from the Traditional Remedy<i>Satureja obovata</i>

Abstract

In the course of screening natural products for smooth muscle relaxant properties, the effects of constituents of Satureja obovata var. obovata (Lamiaceae) on vascular reactivity experiments were studied. Bioassay-guided fractionation led to pure vasodilator compounds, identified by spectroscopic methods as the flavonoids: naringenin, eriodictyol, and luteolin. The relaxant effects induced by different extracts and fractions obtained on KCl (80 mM) and noradrenaline (NA) (10(-6) M) induced contractions on isolated rat aorta were selected as bioassay procedures. The sustained contraction induced by NA (10(-6) M) and K+ (80 mM) were relaxed by luteoline (98.7 +/- 0.7%; 40.30 +/- 2.4%), naringenin (12.41 +/- 1.8%; 3.05 +/- 0.3%), and eriodictyol (67.48 +/- 3.3%; 17.93 +/- 2.1%) each at the dose of 5 x 10(-5)M, respectively.