Vascular diseases arise due to vascular endothelium dysfunction in
response to several pro-inflammatory stimuli and invading pathogens.
Thickening of the vessel wall, formation of atherosclerotic plaques
consisting of proliferating smooth muscle cells, macrophages and
lymphocytes are the major consequences of impaired endothelium resulting
in atherosclerosis, hypercholesterolemia, hypertension, type 2 diabetes
mellitus, chronic renal failure and many others. Decreased nitric oxide
(NO) bioavailability was found to be associated with anomalous
endothelial function because of either its reduced production level by
endothelial NO synthase (eNOS) which synthesize this potent endogenous
vasodilator from L-arginine or its enhanced breakdown due to severe
oxidative stress and eNOS uncoupling. Polyphenols are a group of
bioactive compounds having more than 7000 chemical entities present in
different cereals, fruits and vegetables. These natural compounds
possess many OH groups which are largely responsible for their strong
antioxidative, anti-inflammatory antithrombotic and anti-hypersensitive
properties. Several flavonoid-derived polyphenols like flavones,
isoflavones, flavanones, flavonols and anthocyanidins and non-flavonoid
polyphenols like tannins, curcumins and resveratrol have attracted
scientific interest for their beneficial effects in preventing
endothelial dysfunction. This article will focus on in vitro as well as
in vivo and clinical studies evidences of the polyphenols with eNOS
modulating activity against vascular disease condition while their
molecular mechanism will also be discussed.