Antioxidant activity and inhibition of ultraviolet radiation-induced skin damage of Selenium-rich peptide fraction from selenium-rich yeast protein hydrolysate.

The bioactive peptides and trace element selenium (Se) both have good antioxidant activity. However, whether combined Se and bioactive peptides have more excellent antioxidant activity remain unknown. The aim of this study is to prepare a Se-rich peptide fraction containing both Se and peptides from Se-rich yeast protein hydrolysate and investigated its antioxidant activity and effect on ultraviolet B (UVB) radiation-induced skin oxidative damage. The peptide fractions with different molecular weight (MW) and Se content were obtained by enzymatically hydrolyzing normal or Se-rich yeast proteins followed by a filtration process. In vitro free radical scavenging and lipid peroxidation inhibition assays showed that Se-rich peptides fraction with lower MW of <1 kDa (sSeP) had the highest antioxidant activity compared with Se-rich peptide fractions with higher MW of <3 kDa or normal peptide fractions. Oral administration of sSeP significantly decreased the level of malonaldehyde (MDA) in liver and serum, and increased the activity of glutathione peroxidase (GPx) in liver and serum in normal mice. When topically applied on the dorsal skin of mice, sSeP effectively alleviate UVB radiation-induced skin damage and oxidative stress by increasing GPx and catalase activities and glutathione content in skin or serum. Furthermore, sSeP showed a protective effect against HO-induced cytotoxicity in cultured human epidermal keratinocytes (HaCaT) cells probably by increasing aquaporin-3 expression and attenuating the phosphorylation of p38 MAPK. Overall, the results showed that Se-rich yeast peptide fraction containing Se and bioactive peptides could be a promising antioxidant nutrient used as food additive to enhance the body's antioxidant ability or as cosmeceutical product to minimize the skin oxidative damage.