Prevention of the in vitro oxidation of low density lipoproteins (LDL) by amaranth peptides released by gastrointestinal digestion

GARCÍA FILLERÍA S Y TIRONI VA

Journal of Functional Foods

Elsevier

Año: 2017 vol. 34 p. 197 - 206

1756-4646

LDL oxidation plays a fundamental role in atherosclerosis. Amaranth peptides have been demonstrated to inhibit the formation and/or to scavenge reactive species. The objective of this work was to analyze their capacity to prevent LDL oxidation. A simulated gastrointestinal digest was obtained from protein isolate (Id); Id fractions were separated by gel filtration FPLC, and then synthetic peptides were evaluated. The evolution of conjugated dienes during Cu+2/H2O2-induced-LDL-oxidation was determined by absorbance at 234 nm. Curves (Abs vs time) were fitted to a non-lineal regression model; lag time (LT) and propagation rate (PR) parameters were obtained. Id (0.06-0.23 mg/mL) increased LT (47-82%) and diminished PR (59-68%). Gel-filtered fractions presented diverse behaviors; the more active ones showed molecular weights in the 0.59-1.4 kDa range. Active peptides had at least one hydrophobic and/or aromatic amino acid, and the most active ones presented histidine, suggesting metal chelation as their main action mechanism.