Polyphenols are predominantly found in plants-derived diets
such as fruits and vegetables, providing diverse health benefits.
Many studies have found that polyphenols including epigallocatechin
gallate (EGCG), quercetin, ellagic acid, hesperidin, resveratrol,
and caffeic acid act as antioxidants to inhibit oxidation products
produced by nicotine exposure. Aprevious study found that ellagic acid can act as a chain breaking
antioxidant whose hydroxyl group can readily react with chain
carrying peroxy radicals thus terminating the propagation of free
radical-mediated reactions . Quercetin
directly scavenges the superoxide anion by inhibiting several superoxide
generating enzymes such as xanthine oxidase . For instance, green tea extracts including
EGCG suppressed carcinogenicity induced by NNK that is a
harmful metabolite produced by nicotine . Lin andrevealed that resveratrol protects pulmonary endothelial
cells against the adverse effects of cigarette smokinginduced
oxidative stress and apoptosis.