Production and identification of antioxidant and angiotensin-converting enzyme inhibition and dipeptidyl peptidase IV inhibitory peptides from bighead carp (Hypophthalmichthys nobilis) muscle hydrolysate

- Pepsin hydrolysates of Hypophthalmichthys nobilis muscle protein displayed multiple bioactivities.
- Novel peptides with good antioxidant, DPP-IV and ACE inhibitory activity were identified.
- Peptides were predicted to be non-toxic and some were non-allergenic in silico.

We investigated bioactive peptides obtained from muscle protein hydrolysate of bighead carp by evaluating in vitro dipeptidyl peptidase IV (DPP-IV) and angiotensin-converting enzyme (ACE) inhibitory capacities and antioxidant activity. Peptide sequences were identified from pepsin hydrolysates. Met-Lys-Ala-Val-Cys-Phe-Ser-Leu was one of the most effective sequences with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (EC50 = 4.58 ± 0.15 μM) and relatively high ACE inhibitory capacity (IC50 = 3.68 ± 0.13 μM). Tyr-Asn-Leu-Lys-Glu-Arg-Tyr-Ala-Ala-Trp (IC50 = 1.35 ± 0.23 μM) and Tyr-Asn-Arg-Leu-Pro-Glu-Leu (IC50 = 3.42 ± 0.39 μM) exhibited the most potent ACE inhibitory activity. Ile-Ala-Asp-His-Phe-Leu showed the highest DPP-IV inhibitory activity with an IC50 value of 610.1 ± 82.6 μM. All selected peptides were non-toxic, and most were non-allergenic according to in silico predictions. These results indicate the promising potential of bighead carp muscle hydrolysates as functional additives in foods and pharmaceuticals.