Vasorelaxant effect of stilbenes from rhizome extract of rhubarb (Rheum undulatum) on the contractility of rat aorta.

摘要: The vascular relaxant effect of the rhizome extract Rheum undulatum was evaluated with isolated rat thoracic aorta preparations. methanol induced a concentration-dependent relaxation aortic preparations precontracted 0.3 µm phenylephrine (EC50 value: 5.8 µg/mL). activity-guided fractionation led to isolation seven hydroxystilbene components as active principles, i.e. piceatannol, resveratrol, desoxyrhapontigenin, rhapontigenin, piceid, rhaponticin and e-viniferin. Of these, tetrahydroxystilbene, exhibited most potent in value 2.4 µm). vasorelaxant piceatannol on endothelium-intact rings diminished completely by removal functional endothelium or pretreatment tissues NG-nitro-l-arginine methyl ester. These results suggest that may be major mediator responsible for vasorelaxing properties effects mediated via endothelium-dependent nitric oxide signaling pathway. Copyright © 2006 John Wiley & Sons, Ltd.