EDN1 and endothelial dysfunction: Plant secondary metabolites especially polyphenols such as flavonoids, epicatechin, catechin, anthocyanidins, epigallocatechin gallate, carotenoids, terpenoids, sesquiterpenoids, and unsaturated fatty acids have been reported to protect against the deleterious effects of oxidative stress, reduce blood pressure, and improve endothelial dysfunction through several mechanisms [89, 90] which include activation of eNOS and reduced endothelial ET-1 secretion which are key in NO/cGMP pathway [91–95], as well as through activation of Akt/eNOS pathway [96].