In vitro and in vivo studies on the antioxidant activity of fish peptide isolated from the croaker (Otolithes ruber) muscle protein hydrolysate.

Abstract Peptide from croaker ( Otolithes ruber ) muscle protein hydrolysate was purified, characterized and evaluated for its in vitro and in vivo antioxidant activity. Results showed that purified peptide contained the amino acid sequence as Lys-Thr-Phe-Cys-Gly-Arg-His (861.6 Da), which were expected to contribute to its antioxidant activities. This peptide efficiently quenched 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals (84.5 ± 1.2 and 62.4 ± 2.9%), and successfully inhibits the lipid peroxidation and DNA damage and proven to be a potent antioxidant at different in vitro systems. It also improved the endogenous cellular antioxidant enzymes in Wistar rat by increasing the activities of catalase (CAT), glutathione-S-transferase (GST) and superoxide dismutase (SOD) after supplementation of the peptide (283.6 ± 7.25, 4.3 ± 0.78 and 28.42 ± 1.97) compared to the negative control (196.4 ± 5.65, 1.3 ± 0.45 and 15.1 ± 0.35). Therefore, croaker muscle peptide can increase an endurance capacity and facilitate recovery from oxidative stress.