Inhibition of Hemoglobin- and Iron-Promoted Oxidation in Fish Microsomes by Natural Phenolics

Abstract

Natural phenolic antioxidants have been tested in hake (Merluccious merluccious) microsomes as inhibitors of lipid oxidation promoted by fish muscle prooxidants: hemoglobin (Hb), enzymatic NADH-iron and nonenzymatic ascorbate-iron. The phenolics selected were as follows: (a) a grape phenolic extract (OW), (b) a fraction (IV) with isolated grape procyanidins with a medium-low degree of polymerization and galloylation percentage, (c) hydroxytyrosol obtained from olive oil byproducts, and (d) a synthetic phenolic antioxidant, propyl gallate. All compounds delayed lipid oxidation activated by Hb, enzymatic NADH-iron, and nonenzymatic ascorbate-iron, excluding hydroxytyrosol that was not an effective antioxidant on oxidation promoted by nonenzymatic iron. The relative antioxidant efficiency was independent of the prooxidant system, IV > propyl gallate > OW > hydroxytyrosol, and showed a positive correlation with their incorporation into microsomes (p < 0.05). The reducing capacity or ability for donating electrons and the chelating properties may also contribute to the antioxidant activity of phenolics, although these factors were less decisive than their affinity for incorporating into the microsomes. Conversely, the inhibition of Hb oxidation by phenolics and their polarity did not seem to play an important role on antioxidant mechanism. These results stressed the importance of incorporating the exogenous antioxidants into the membranes where are located key substances for fish lipid oxidation (highly unsaturated phospholipids, iron-reducing enzymes, and endogenous alpha-tocopherol).

Antioxidant properties and bioactive components of Norton (Vitis aestivalis) and Cabernet Franc (Vitis vinifera) wine grapes

“…The antioxidant activity of grapes has been positively associated with their phenolic composition such as anthocyanins, flavonols, flavan-3-ols, procyanidins, and phenolic acids (Bertelli, Falchi, Lo Scalzo, & Morelli, 2004;Fujii et al, 2007;Kedage, Tilak, Dixit, Devasagayam, & Mhatre, 2007;Pazos, Lois, Torres, & Medina, 2006;Shafiee, Carbonneau, Urban, Descomps, & Leger, 2003). Additionally, these compounds have been shown to reduce hydroperoxide formation and inhibit both lipid and protein oxidation (Heinonen et al, 1998).…”

Assessment of Washing with Antioxidant on the Oxidative Stability of Fatty Fish Mince during Processing and Storage

“…PG and SP accumulated in the mince and reached 585 and 4010 mg/kg, respectively, after the third wash, revealing their affinity for muscle protein. In a glassing experiment, phenolics extract from grape has been shown to be quickly transferred from the aqueous phase into the fish muscle and to have high affinity for the fish muscle membrane (27). Of the three antioxidants tested, PG was the most hydrophobic and might have accumulated in hydrophobic cavities of fish proteins or associated with hydrophobic amino acids.…”

Alterations in the Intestinal Assimilation of Oxidized PUFAs Are Ameliorated by a Polyphenol-Rich Grape Seed Extract in an In Vitro Model and Caco-2 Cells

“…Fish muscle contains prooxidants, such as hemoproteins and low-molecular weight iron (12). Hemoglobin in fish has been shown to be more active in promoting oxidation under acidic conditions, where the release of heme groups by gastric proteolytic activity could act as a catalyst of lipid oxidation as well (13).…”