In vitro antioxidant activity of the total polyphenolic fraction of extra virgin olive oil (Olea europaea L.), blend type and its protective effect against rat erythrocyte haemolysis

Abstract

The intake of extra virgin olive oil (EVOO) has been associated with a lower incidence of degenerative diseases, due at least in part to its polyphenol content. The objective of this study was to examine the functional properties of the total polyphenolic fraction (TPF) of four EVOOs from Argentina. To our knowledge, there are no studies available thatexamine the antioxidant properties of EVOO TPF in biological membranes. The TPF was evaluated by the following assays: total polyphenol content (TPC), antioxidant activity (AA) against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the protective effect of TPF on oxidative damage induced by both hypotonic solution and the radical initiator 2,2’-azobis(2-amidinopropane) dichlorohydrate (AAPH) in rat erythrocytes. The TPC ranged from 125.7 ± 1.8 mg·kg-1 to 213.2 ± 2.9 mg·kg-1. AA values were 340.0 ± 8.7 mmol·kg-1 to 533.2 ± 8.7 mmol·kg-1. TPF moderately inhibited haemolysis induced by AAPH and hypotonic solution. These findings suggest that EVOO TPF is an important source of natural antioxidants; it has effective AA against diverse reactive species and protects rat erythrocytes against oxidative damage. The data obtained provide new experimental evidence of the protective role of TPC in EVOO derived from a blend of olive varieties against oxidative stress in biological systems.