Effect of oral administration of collagen hydrolysates from Nile tilapia on the chronologically aged skin

Abstract The oral ingestion of collagen hydrolysates (CHs) seems popular nowadays, but there has been little report on the chronological aging of skin so far. A CHs (average molecular weight = 624.72 Da) was prepared from the skin of Nile tilapia by simulated gastrointestinal digestion in this study. It exhibited high yield (97.04%), digestibility (98.12%) and antioxidant activity towards 1,1-diphenyl-2-picrylhydrazyl radical (half maximal inhibitory concentration, IC 50  = 2.57 mg/mL) and linoleic acid peroxidation (IC 50 = 0.36 mg/mL). The safety (4.07 g/kg bw·d) was also confirmed through the feeding of 9-month-old mice for 180 days. More importantly, the visual appearance, histological structure and matrix homeostasis of mice skin were remarkably improved. Furthermore, oxidative stress was alleviated by enhancing the activities of antioxidant enzymes, which was an important reason for the improvement of skin properties. These suggested its potential to be exploited into new functional foods with the effect against chronological aging of skin.