Antioxidant effects of phenolic rye (Secale cereale L.) extracts, monomeric hydroxycinnamates, and ferulic acid dehydrodimers on human low-density lipoproteins
Mf. Andreasen et al., Antioxidant effects of phenolic rye (Secale cereale L.) extracts, monomeric hydroxycinnamates, and ferulic acid dehydrodimers on human low-density lipoproteins, J AGR FOOD, 49(8), 2001, pp. 4090-4096
Dietary antioxidants that protect low-density lipoprotein (LDL) from oxidat
ion may help to prevent atherosclerosis and coronary heart disease. The ant
ioxidant activities of purified monomeric and dimeric hydroxycinnamates and
of phenolic extracts from rye (whole grain, bran, and flour) were investig
ated using an in vitro copper-catalyzed human LDL oxidation assay. The most
abundant ferulic acid dehydrodimer (diFA) found in rye, 8-O-4-diFA, was a
slightly better antioxidant than ferulic acid and p-coumaric acid. The anti
oxidant activity of the 8-5-diFA was comparable to that of ferulic acid, bu
t neither 5-5-diFA nor 8-5-benzofuran-diFA inhibited LDL oxidation when add
ed at 10-40 muM. The antioxidant activity of the monomeric hydroxycinnamate
s decreased in the following order: caffeic acid > sinapic acid > ferulic a
cid > p-coumaric acid. The antioxidant activity of rye extracts was signifi
cantly correlated with their total content of monomeric and dimeric hydroxy
cinnamates, and the rye bran extract was the most potent. The data suggest
that especially rye bran provides a source of dietary phenolic antioxidants
that may have potential health effects.