Antioxidant and Antiapoptotic Properties of Oat Bran Protein Hydrolysates in AAPH-Induced Oxidative Stress Hepatocarcinoma HepG2

The aim of this study was to determine the antioxidant activity of protein hydrolysates derived from enzymatic digestion of oat bran (OBPHs) using two two polysaccharides degrading enzymes (Viscozyme and Cellulase) and four proteases (Flavourzyme, papain, Protamex, and Alcalase) in chemistry based and HepG2 cell cultures. In the oxygen, radical absorbance capacity (ORAC) assay, the peroxyl radical scavenging activity was the highest in Cell/Papa (417.0 ± 5.1 Trolox Equivalent (TE)/g), and in ABTS•+ (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid)) radical scavenging assay was the highest in Visc/Flav (863.80 ± 20.3 TE/g). In hepatic HepG2 cells culture assays, OBPHs from Viscozyme treated brans and Cell/Flav OBPH showed better efficiency in antioxidant activity induced by 2,2’-Azobis-2-methyl-propanimidamide dihydrochloride (AAPH). OBPHs protected HegG2 cells from oxidative stress due to a combination of factors including radical scavenging activity, upregulation of antioxidant enzymes, and inhibition of the activity of the apoptotic enzyme caspase-3.