Purification, identification, and antioxidative mechanism of three novel selenium-enriched oyster antioxidant peptides

• Published in: Food research international 2022-07, Vol.157, p.111359-111359, Article 111359
• Main Authors: Xia, Zhen, Miao, Jianyin, Chen, Bingbing, Guo, Junbin, Ou, Yingyi, Liang, Xingtang, Yin, Yanzhen, Tong, Xing, Cao, Yong
• Format: Article
• Language: English
• Subjects: Activity mechanism; amino acids; antioxidant activity; antioxidants; cell viability; Cellular antioxidant activity; Characterization; Cytoprotective effect; food research; functional foods; hydrogen; hydrolysates; hydrophobicity; medicine; Molecular docking; oxidative toxicity; oysters; peptides; Se-enriched antioxidant peptides; Se-enriched oyster; selenium
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2022.111359

[Display omitted] •The Se-enriched oyster antioxidant peptides were purified by RP-HPLC.•Three novel Se-enriched peptides LLVSeMY, MMDSeML, and VSeMDSeML were obtained.•Se-enriched peptides exhibited excellent cellular antioxidant activity and cytoprotective effect.•The antioxidative mechanism of Se-enriched peptides were predicted using molecular docking. Natural organic selenium (Se) has multiple physiological health benefits and has become a hotspot of research in recent years. In this study, the Se-enriched antioxidant peptides were purified from Se-enriched oyster hydrolysate. Three novel Se-enriched antioxidant peptides LLVSeMY (685.2953 Da), MMDSeML (687.1875 Da) and VSeMDSeML (703.1599 Da) were identified from fraction F6-4, which all exhibited strong cellular antioxidant activity (CAA) with EC50 values of 0.739, 0.423, and 0.395 μg/mL, respectively. These three Se-enriched antioxidant peptides (0.025 mg/mL) could significantly enhanced cell viability to 84.60 ± 3.32% ∼ 86.18 ± 1.36% compared with the AAPH injury group (75.99 ± 0.79%), and the cytoprotective effects were even better than that of GSH (80.47 ± 2.78%). Moreover, these three Se-enriched peptides also significantly protected HepG2 cells from AAPH-induced oxidative injury by inhibiting ROS production and enhancing the activities of antioxidant enzymes. The molecular docking results showed that these three Se-enriched peptides can form stable hydrogen and hydrophobic bonds with key amino acid residues of Keap1 protein, thereby potentially regulating the Keap1-Nrf2 pathway. In conclusion, the three novel Se-enriched oyster antioxidant peptides are expected to be used in medicine or functional food, providing a new theoretical basis for the high-value utilization of natural organic Se.