The aim of the present study was to evaluate the vascular effects of an enzymatic extract of grape pomace
(GP-EE) on isolated arteries, focusing our attention on endothelium-derived relaxation and on its antioxidant properties. Grape pomace derived from wine making was extracted by an enzymatic process and its
composition of polyphenols was evaluated by HPLC and ESI-MS/MS, detecting kaempferol, catechin,
quercetin and procyanidins B1 and B2, trace levels of resveratrol and tracing out gallocatechin and anthocyanidins. GP-EE induced endothelium- and NO-dependent vasodilatation of both rat aorta and small
mesenteric artery (SMA) segments and reduced Phe-induced response in aortic rings. Both ORAC and
DPPH assays confirmed antioxidant scavenging properties of GP-EE, which also prevented O
2 production
(assessed by DHE fluorescence) and contraction elicited by ET-1. These results provide evidence that
GP-EE possesses interesting antioxidant and protective vascular properties and highlight the potential
interest of this extract as a functional food