Peptides derived from casein hydrolyzed by Lactobacillus: Screening and antioxidant properties in H2O2-induced HepG2 cells model

Protein hydrolysates and peptides in fermented dairy products exhibit antioxidant activities. This study aimed to evaluate the antioxidant properties of casein and whey protein hydrolysates derived from three lactic acid bacteria. The assessment involved the observation of Reactive oxygen species (ROS), Malondialdehyde (MDA) content, Superoxide dismutase (SOD), Catalase (CAT), cell morphology and chromatin in H2O2 induced HepG2 cell model. Casein hydrolyzed by Lactobacillus reuteri exhibited higher antioxidant activity. ROS content decreased by 44.7 %, while SOD and CAT activities increased by 48 % and 194 %, respectively. Furthermore, it was confirmed that the peptide VKEAMAPK derived from Lactobacillus reuteri's casein hydrolysate possessed significant antioxidant potential. The docking analysis of VKEAMAPK peptide and Keap1 protein showed that they were stably bound outside the Kelch domain and formed a non-competitive inhibition effect. Additionally, this study lights on the antioxidant properties of milk-derived peptides screened from hydrolysates.