title: Standardization of a method to evaluate the antioxidant capacity of high-density lipoproteins.
abstract: BACKGROUND
  A method to evaluate the antioxidant capacity of high-density lipoprotein (HDL) was developed and standardized.
  
  
  METHODS
  This method measure conjugated diene (CD) formation and electrophoretic mobility of low-density lipoprotein (LDL) in agarose gels in the presence and absence of HDL. HDL was isolated from 1 mL of plasma within 24 hours and oxidation assays were performed within 6 hours. Oxidation was induced by adding CuSO4. The lag phase increase in CD kinetics and the inhibition of electrophoretic mobility were defined as the HDL antioxidant capacity.
  
  
  RESULTS
  The optimal conditions for the CD assay were 2.5 μM CuSO4, LDL at 0.1 g apoB/L, HDL at 0.1 g apoA-I/L, at 37°C and for 3h 50 min. Agarose electrophoresis at 100 V, at 4°C for 50 min was then performed immediately. CD formation variability was 21.1% for inter-assay CV and 12.7% for intra-assay CV. Electrophoretic mobility was 26.5% for inter-assay CV and 2.4% for intra-assay CV. Correlation analysis showed a significant association between the antioxidant capacity of HDL and its neutral/polar lipid ratio.
  
  
  CONCLUSIONS
  The method herein described measures of the HDL antioxidant capacity in a reproducible and rapid manner that can be applied to a relatively high number of samples.
authors.affiliation: Department of Biochemistry, Institut de Recerca, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: de Juan-Franco
authors.forename: Antonio
authors.initials: A
authors.lastname: Pérez
authors.forename: Vicent
authors.initials: V
authors.lastname: Ribas
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Sánchez-Hernández
authors.forename: Francisco
authors.initials: F
authors.lastname: Blanco-Vaca
authors.forename: Jordi
authors.initials: J
authors.lastname: Ordóñez-Llanos
authors.forename: José Luis
authors.initials: JL
authors.lastname: Sánchez-Quesada
keywords: HDL; HDL antioxidant capacity; LDL; lipoproteins