Many in vitro studies have clearly revealed the potent role of flavonoids in inhibiting lipid peroxidation and oxidation of low-density lipoproteins (LDL). It has been proposed that flavonoids near membrane surfaces are ideally located for scavenging free radicals generated in the aqueous phase. For example, it has been debated that catechins might prevent the oxidation of vitamin E (a lipophilic antioxidant) by scavenging hydrophilic radicals near membrane surfaces, whereas vitamin E scavenges lipid peroxyl radicals (LOO•) as hydrogen donor to stop free radical chain reactions (chain-breaking antioxidant). Polyphenols could also play a role in the regeneration of vitamin.
