Inhibition of Low-Density Lipoprotein Peroxidation by BHA Use: Fluorimetric Assay

Abstract

In the presence of free radicals, low-density lipoproteins (LDL) undergo oxidation that leads to the formation of lipoperoxides, which cause various damaging effects. Starting from the classical oxygen radical absorption capacity (ORAC) method, a modified method was formulated to develop a laboratory model that is able to deliver information about the use of polyphenols as nutrient supplements. The aim of this work was to establish the possible inhibition of LDL peroxidation by two different antioxidants, Trolox and BHA, and to assess if the effect is either of prevention or repair. 2,2,-Azobis(2-methylpropionamidine) dihydrochloride (AAPH) was used as free radical generator, and fluorescein was used as fluorescent probe. It was noticed that the radical scavenging effect decreases in the order BHA to Trolox to LDL itself. Trolox shows a higher efficacy against the free radicals generated by AAPH than against lipoperoxides, whereas BHA is more efficient against lipoperoxides.

Keywords:

• Antioxidant
• lipoprotein lipid peroxidation
• ORAC
• polyphenol

Acknowledgments

This work was supported by the European project NUTRA-SNACK (E.C. F.P.6 Contract No. FOOD-CT-2006-023044).