In silico prospecting of ADH activating peptides from Pacific oyster (Crassostrea gigas) and protective effect on ethanol-induced damage in HepG2 cells

Alcoholic liver disease (ALD) is becoming a major health threat in the world today. Alcohol dehydrogenase (ADH) plays an important role in alcohol metabolism. Pacific oyster (Crassostrea gigas) has been identified as a food-borne hepatoprotective agent. For the first time, we integrated in silico strategy, including simulated hydrolysis, bioinformatic prediction and molecular docking to screen ADH activating peptides from C. gigas. In vitro ADH activation activity and surface plasmon resonance (SPR) results showed that this strategy could stably screen ADH activating peptides. We selected six of them to further verify their protective effect on EtOH-induced HepG2 cells. Among them, peptide LQPPR (Leu-Gln-Pro-Pro-Arg) pretreatment increased cell viability, can effectively resist EtOH-induced cytotoxicity. And the transaminase (ALT, AST) in the cell supernatant decreased, indicating the cell damage was improved. The results also showed that the antioxidant capacity (SOD, GSH) of LQPPR pretreated cells increased, and the oxidative stress (MDA) decreased.