Abstract:

A ferric ion-reducing system and three free radical systems were used to evaluate the radical-scavenging capacity
and antioxidant activity of collagen peptides from Lophius litulon skin in vitro. The peptide components were separated by
ultrafiltration and the fraction with the highest hydroxyl radical scavenging activity in vitro was obtained. In addition, aged
mouse models were constructed and determined for SOD, CAT, GSH-Px, MDA and Hyp contents in the skin after oral
administration of the screened fraction. The results showed that Lophius litulon skin collagen peptides had strong reducing
power and superoxide anion, DPPH and hydroxyl radical scavenging capacity in vitro. When the sample concentration was
10 mg/mL, the scavenging rates of hydroxyl, DPPH and superoxide anion radicals and the ferric ion reducing power were
70.48%, 68.78%, 42.53% and 0.676, respectively. The fraction with relative molecular weight less than 2 000 D had stronger
hydroxyl radical scavenging activity, and its IC50 was 15.7 mg/mL. The activities of SOD, GSH-Px and CAT in skin were
increased by respectively 20.9%, 41.3% and 58.1% at the dose of 100 mg/(kg·d) when compared with the model group.
Moreover the generation of MDA was significantly inhibited.

Key words: Lophius litulon skin, collagen peptide, antioxidant activity, malondialdehyde, hydroxyproline