Plant-derived phenolics inhibit the accrual of structurally characterised protein and lipid oxidative modifications

Abstract

Epidemiological data suggest that plant-derived phenolics beneficial effects include an inhibition of LDL oxidation. After applying a screening method based on 2,4-dinitrophenyl hydrazine- protein carbonyl reaction to 21 different plant-derived phenolic acids, we selected the most antioxidant ones. Their effect was assessed in 5 different oxidation systems, as well as in other model proteins. Mass-spectrometry was then used, evidencing a heterogeneous effect on the accumulation of the structurally characterized protein carbonyl glutamic and aminoadipic semialdehydes as well as for malondialdehyde-lysine in LDL apoprotein. After TOF based lipidomics, we identified the most abundant differential lipids in Cu++-incubated LDL as 1-palmitoyllysophosphatidylcholine and 1-stearoyl-sn-glycero-3-phosphocholine. Most of selected phenolic compounds prevented the accumulation of those phospholipids and the cellular impairment induced by oxidized LDL. Finally, to validate these effects in vivo, we evaluated the effect of the intake of a phenolic-enriched extract in plasma protein and lipid modifications in a well-established model of atherosclerosis (diet-induced hypercholesterolemia in hamsters). This showed that a dietary supplement with a phenolic-enriched extract diminished plasma protein oxidative and lipid damage. Globally, these data show structural basis of antioxidant properties of plant-derived phenolic acids in protein oxidation that may be relevant for the health-promoting effects of its dietary intake. that a dietary supplement with a phenolic-enriched extract diminished plasma protein oxidative and lipid damage. Globally, these data show structural basis of antioxidant properties of plant-derived phenolic acids in protein oxidation that may be relevant for the health-promoting effects of its dietary intake.

This study was supported in part by Research and Development grants from the Spanish Ministry of Education and Science (BFU2006-14495/BFI) and the Generalitat of Catalunya (2005SGR00101) to RP; the Spanish Ministry of Health (FIS 04-0355, 05-2214 and 05-2241) to MPO, Spanish Ministry of Education and Science (AGL2005-07881-C02-01 and AGL2006-12433) to MJM and MPO. Supported partially by the COST B-35 Action. The present work was supported by the CENIT program from the Spanish Minister of Industry and by a consortium of companies led by La Morella Nuts S. A. (Reus, Catalonia, Spain) with the following companies: Shirota Functional Foods, S. L.; KRAFT; BTSA, Biotecnologías Aplicadas, S. L.; Selección Batallé, S. A.; Industrial Técnica Pecuaria, S. A.; Neuron BioPharma, S. A.; Grupo Leche Pascual, S. A. U.; Innaves, S. A. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.