Collagen Peptides from Swim Bladders of Giant Croaker () and Their Protective Effects against HO-Induced Oxidative Damage toward Human Umbilical Vein Endothelial Cells.

Five different proteases were used to hydrolyze the swim bladders of and the hydrolysate treated by neutrase (collagen peptide named SNNHs) showed the highest DPPH radical scavenging activity. The extraction process of SNNHs was optimized by response surface methodology, and the optimal conditions were as follows: a temperature of 47.2 °C, a pH of 7.3 and an enzyme concentration of 1100 U/g, which resulted in the maximum DPPH clearance rate of 95.44%. Peptides with a Mw of less than 1 kDa (SNNH-1) were obtained by ultrafiltration, and exhibited good scavenging activity for hydroxyl radicals, ABTS radicals and superoxide anion radicals. Furthermore, SNNH-1 significantly promoted the proliferation of HUVECs, and the protective effect of SNNH-1 against oxidative damage of HO-induced HUVECs was investigated. The results indicated that all groups receiving SNNH-1 pretreatment showed an increase in GSH-Px, SOD, and CAT activities compared with the model group. In addition, SNNH-1 pretreatment reduced the levels of ROS and MDA in HUVECs with HO-induced oxidative damage. These results indicate that collagen peptides from swim bladders of can significantly reduce the oxidative stress damage caused by HO in HUVECs and provides a basis for the application of collagen peptides in the food industry, pharmaceuticals, and cosmetics.