Food-derived bioactive peptides from macauba (Acrocomia aculeata) kernel protein improve oxidative stress resistance in Caenorhabditis elegans

Enzymatic hydrolysis enhances the release of bioactive peptides from food proteins, generating compounds capable of influencing biological processes associated with health. Macauba (Acrocomia aculeata) kernel proteins represent an underexplored source of these molecules. This study aimed to characterize a protein hydrolysate produced by Alcalase (HA) and evaluate its toxicity and ability to enhance resistance to oxidative stress using Caenorhabditis elegans as an in vivo model. Macauba kernel protein isolate was hydrolyzed with Alcalase and the resulting hydrolysate was characterized by SDS-PAGE, nanoLC-ESI-MS/MS, and bioinformatic prediction of peptide bioactivity. Antioxidant capacity was determined by the ABTS radical scavenging assay (1%, w/v). Toxicity and oxidative stress resistance were evaluated in synchronized L4 C. elegans exposed to macauba kernel protein isolate (IS) or HA. Toxicity was assessed after exposure to each treatment (0,1 to 0,5%) for 24 hours, while oxidative stress resistance was determined by challenging the treated (0,5%) nematodes with hydrogen peroxide for 4 hours and expressing survival as the percentage of live animals after the oxidative challenge. SDS-PAGE revealed peptide fractions predominantly below 20 kDa, indicating extensive proteolysis. NanoLC-ESI-MS/MS identified peptides ranging from 571 to 1595 Da (6–13 amino acids) with high sequencing confidence (10lgP > 20 and confident amino acid probabilities predominantly at 100%). Approximately 55% of the identified sequences were predicted by bioinformatic analysis to possess antioxidant-related bioactivity, supporting the functional potential of the hydrolysate. Consistent with these findings, HA exhibited strong ABTS radical scavenging activity (82.08 ± 4.28% inhibition at 1%, w/v). In the toxicity assay, no significant effect on the survival of organisms exposed to the treatments was observed compared with the control groups. Exposure to hydrogen peroxide established a concentration-dependent oxidative stress model, reducing C. elegans survival from 95.3% in untreated animals to 51.3%, 8.0%, and 0.7% following exposure to 4, 8, and 12 mM H₂O₂, respectively. Treatment with HA significantly increased survival compared with the oxidatively stressed control at both H₂O₂ concentrations evaluated. At 8 mM H₂O₂, HA maintained survival at approximately 91%, significantly exceeding the survival observed for the non-hydrolyzed isolate and preserving protection despite the higher oxidative challenge. The agreement between peptide characterization, chemical antioxidant capacity, and improved survival under oxidative challenge suggests that alcalase hydrolysis releases peptide-rich fractions capable of increasing organismal resilience to oxidative stress. These findings support macauba-derived protein hydrolysates as promising food-derived bioactives and encourage further investigation of the molecular mechanisms underlying their health-promoting effects and potential applications in functional foods.

Acknowledgments: CAPES. S.Oleum.