Sunflower seed-derived bioactive peptides show antioxidant and anti-inflammatory activity: From in silico simulation to the animal model

The evolving field of food technology is increasingly dedicated to developing functional foods. This study explored bioactive peptides from sunflower protein isolate (SPI), obtained from defatted flour, a by-product of the oil processing industry. SPI underwent simulated gastrointestinal digestion and the obtained peptide-enriched fraction (PEF) showed antioxidant properties in vivo, in zebrafish. Among the peptides present in PEF identified by mass spectrometry analysis, we selected those with antioxidant properties by in silico evaluation, considering their capability to interact with Keap1, key protein in the regulation of antioxidant response. The selected peptides were synthesized and evaluated in a cellular model. As a result, DVAMPVPK, VETGVIKPG, TTHTNPPPEAE, LTHPQHQQQGPSTG and PADVTPEEKPEV activated Keap1/Nrf2 pathway leading to Antioxidant Response Element-regulated enzymes upregulation. Since the crosstalk between Nrf2 and NF-κB is well known, the potential anti-inflammatory activity of the peptides was assessed and principally PADVTPEEKPEV showed good features both as antioxidant and anti-inflammatory molecule.