Screening and preparation of highly active antioxidant peptides of apricot and their inhibitory effect on ultraviolet radiation

Abstract

In today's social environment, the objective reality of people's increasing life pressure, environmental deterioration, and enhanced ultraviolet rays caused by the destruction of the ozone layer has led to the aggravation of people's oxidative stress. Therefore, exogenous antioxidant peptides have become a hot topic in research. In the context of insufficient protein supply and resource recycling, almond meal was used as raw material in this study. As a by-product of oil processing, it has a protein content of 68 % and antioxidant-related amino acids accounted for 84.62 %, which can be used as a high-quality natural source of antioxidant peptides. Taking antioxidant activity as the only indicator, papain was screened as a hydrolase, and 7 antioxidant peptides such as YLSF, LPSYVN and SPHWNVN were separated and purified. The affinity energy of docking with Keap1-Nrf2-ARE protein molecules was -7.5--8.9 kal/mol, and hydrophobic stacking, hydrogen bonding and intermolecular forces were maintained. Seven antioxidant peptides were synthesized in solid phase, and the IC₅₀ values of in vitro ABTS⁺ scavenging rates were 3.59 μg/mL-6.73 μg/mL, and the antioxidant capacity was stronger than that of glutathione and ascorbic acid. In the in vitro cellular ROS scavenging capacity, all seven peptides had the effect of scavenging intracellular ROS, among which YLSF and ESWNPRDPQF had stronger scavenging capacity than glutathione. Finally, the mouse skin staining method determined that apricot antioxidant peptides had a significant inhibitory effect on UV damage to mouse skin, and targeted proteomics was used to clarify that apricot antioxidant peptides inhibited UV damage by mainly affecting three pathways, including the base excision repair pathway. This study not only improved the economic value of processing by-products, but also obtained 7 highly active almond antioxidant peptides, tapping the potential ability of apricot antioxidant peptides to be incorporated into functional food or cosmetic formulations.

Keywords: Amino acids; Antioxidant activity; Antioxidant peptides; Apricot; Molecular docking; Ultraviolet damage inhibition proteomics.