Peptidomic and in silico screening of six novel antioxidant and hepatoprotective peptides in Musculus senhousei: The vital role of Trp residue

Abstract

Studies have shown that Musculus senhousei hydrolysate is an ideal source of bioactive peptides exerting antioxidant and hepatoprotective activities. However, the structural feature of the active peptide sequences is not yet clear. Hence, in this study, a peptidomic strategy was applied to reveal six novel Trp-containing peptides (CVKWML, WWL, WDRW, WWWV, RSPWR, and WPRCQL) from a hepatoprotective Musculus senhousei hydrolysate. Results from quantum chemical calculations and molecular docking indicated that these peptides could scavenge free radicals through donating electrons via the Trp residues and non-covalent interaction with the key antioxidative target of Keap1. In vitro antioxidant activity assays validated that WWWV and WPRCQL exert over 2 folds of ABTS radical scavenging activity as compared with trolox. In HepG2 cell model, all the six antioxidant peptides increased cell viability as suppressed by alcohol exposure, especially WWWV, WPRCQL and WDRW. These antioxidant peptides alleviated alcohol-induced hepatocyte injury by reducing the reactive radical species (ROS) and aminotransferases (AST and ALT) levels of hepatocytes. Overall, results obtained suggested that Trp residues play a vital role in the antioxidant and hepatoprotective activity of peptides, providing valuable insights for further developing Musculus senhousei peptides as hepatoprotective functional food ingredients.