Effects of bovine .ALPHA.-lactalbumin on ethanol-induced gastric mucosal inflammation in rats

We previously found that bovine α-lactalbumin (a-LA), a major milk protein, protects the gastric mucosa in several animal models of gastric ulcers. In the present study, we investigated the effects of α-LA on ethanol-induced gastric mucosal inflammation. Either α-LA or distilled water (control) was administered into the stomachs of Wistar rats, and after 30 minutes, 60% ethanol containing 100 mM HCI was administered to induce stomach injury. Gastric inflammation was assessed by measuring serum pepsinogen (PG, diagnostic marker for gastric mucosal inflammation), gastric mucosal IL-1β (proinflammatory cytokine), mucosal myeloperoxidase (MPO, neutrophil marker enzyme) and mucosal thiobarbituric acid reaction substrates (TBARS, lipid peroxidation marker). Pre-administration of α-LA (500 mg/kg) significantly suppressed gastric hemorrhagic lesions caused by ethanol. This was accompanied by the suppression of increases in serum PG, mucosal IL-1 p, mucosal MPO activity and mucosal TBARS. These results indicate that α-LA inhibits ethanol-induced gastric mucosal inflammation and that this inhibitory action may be involved in the gastroprotective activities of α-LA.