Neuroprotective effects of different molecular weight peptide fractions obtained from beef by hydrolysis with commercial enzymes in SH-SY5Y cells

The neuroprotective effect of peptide fractions of different molecular weights obtained from beef by commercial enzymes in SH-SY5Y cells was investigated. The < 3 kDa and < 10 kDa peptide fractions were obtained by hydrolysis using inexpensive commercial enzymes (alkaline-AK and papain). The resulting peptide fractions decreased the apoptotic ratio by 20.06% to 33.25% in hydrogen peroxide treated SH-SY5Y cells. Moreover, the peptide fractions obtained by alkaline-AK and papain did not affect cytotoxicity. In addition, the < 3 kDa peptide fractions obtained using alkaline-AK reduced DNA fragmentation and reactive oxygen species generation, and increased superoxide dismutase activity and catalase levels in H2O2 treated SH-SY5Y cells. Furthermore, the < 3 kDa and < 10 kDa peptide fractions showed strong antioxidant activities in 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, iron chelation, and reducing power tests. The present results suggest that the < 3 kDa peptide fractions obtained using alkaline-AK have superior neuroprotective activity and antioxidative activities.