Abstract: The study investigated the protective effect of walnut oligopeptides (WOPs) against absolute ethanol-induced gastric injury, and it also explored the possible underlying mechanism. Male Sprague Dawley (SD) rats were randomly divided into eight groups based on body mas (n = 10), including normal, model, whey protein (440 mg/kg mb), omeprazole (20 mg/kg mb), low-, medium- and high-dose WOP (220, 440, 880 mg/kg mb, respectively) and WOPs (440 mg/kg mb) + bovine collagen oligopeptides (BCOPs, 1.5 g/kg mb) groups. After oral gavage for 30 days, the rats were administered with 5 mL/kg mb of absolute ethanol to induce gastric ulcer, then the gross lesion of gastric tissue was observed and scored, and the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gastric mucin (MUC), pepsinogen (PG) and gastrin (GAS) were detected. The results showed that administration with WOPs markedly mitigated the hemorrhagic gastric lesions caused by ethanol in rats, inhibited the increase in serum ALT and AST levels and gastric PGI, PGII and GAS levels, and enhanced MUC biosynthesis. These results indicated that WOPs have obvious protective effects against ethanol-induced gastric mucosal injury in rats mainly by attenuating the gastric mucosal damage directly caused by ethanol, inhibiting the biosynthesis of PG and GAS, and enhancing MUC biosynthesis.

Key words: walnut oligopeptides; absolute ethanol; gastric mucosal injury