The amino-carbonyl (Maillard) reaction of
amino acids with
sugars is a nonenzymatic browning reaction that takes place during the processing, cooking, and storage of foods.
Maillard reaction products (MRPs) have been shown to possess interesting chemical and
biological properties including antimutagenic and
antioxidant activity. In this study, we determined the
antioxidant effects of
fructosyl arginine (
Fru-Arg), a MRP in aged garlic extract.
Low density lipoprotein (
LDL) was incubated with Cu(2+) at 37 degrees C and 5% CO(2) for 24 hours, which resulted in an increase of
thiobarbituric acid reactive substances (
TBARS) indicating lipid peroxidation. Coincubation of Cu(2+) with
Fru-Arg and
LDL resulted in a significant inhibition of
TBARS formation. Pulmonary artery endothelial cells (PAEC) were exposed to 0.1 mg/mL
oxidized LDL (
Ox-LDL) at 37 degrees C and 5% CO(2) for 24 hours.
Lactate dehydrogenase (LDH) release, as an index of cell membrane damage, and
TBARS were measured.
Ox-LDL caused an increase of LDH release and
TBARS formation. Pretreatment of PAEC with
Fru-Arg inhibited these changes. Murine macrophages were incubated with
Ox-LDL, and the release of
peroxides was measured using a fluorometric assay.
Ox-LDL caused an increased release of
peroxides. Coincubation of macrophages with
Fru-Arg and
Ox-LDL inhibited the release of
peroxides dose-dependently. In a cell free system,
Fru-Arg was shown to scavenge
hydrogen peroxide. These data suggest that
Fru-Arg is a potent
antioxidant, and thus may be useful for the prevention of
atherosclerosis and other disorders associated with oxidative stress.