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.