Combined astaxanthin and fish oil supplementation improves glutathione-based redox balance in rat plasma and neutrophils

The present study aimed to investigate the effects of daily (45 days) intake of fish oil (FO; 10 mg EPA/kg body weight (BW) and 7 mg DHA/kg BW) and/or natural ASTA (1 mg ASTA/kg BW) on oxidative stress and functional indexes of neutrophils isolated from Wistar rats by monitoring superoxide (O-2(center dot-)), hydrogen peroxide (H2O2), and nitric oxide (NO center dot) production compared to the progression of auto-induced lipid peroxidation and Ca2+ release in activated neutrophils. Furthermore, phagocytic capacity, antioxidant enzyme activities, glutathione-recycling system, and biomarkers of lipid and protein oxidation in neutrophils were compared to the redox status. Our results show evidence of the beneficial effects of FO + ASTA supplementation for immune competence based on the redox balance in plasma (significant increase in GSH-dependent reducing power), non-activated neutrophils (increased activity of the glutathione-recycling enzymes GPx and GR) and PMA-activated neutrophils (lower O-2(center dot-), H2O2, and NO center dot generation, reduced membrane oxidation, but higher phagocytic activity). Combined application of ASTA and FO promoted hypolipidemic/hypocholesterolemic effects in plasma and resulted in increased phagocytic activity of activated neutrophils when compared with ASTA or FO applied alone. In PMA-activated neutrophils, ASTA was superior to FO in exerting antioxidant effects. The bulk of data reinforces the hypothesis that habitual consumption of marine fish (e.g. salmon, which is a natural source of both astaxanthin and fish oil) is beneficial to human health, in particular by improving immune response and lowering the risk of vascular and infectious diseases. (C) 2012 Elsevier Ireland Ltd. All rights reserved.