Bovine milk-derived α-lactalbumin prevents hepatic fibrosis induced by dimethylnitrosamine via nitric oxide pathway in rats

The present study was designed to evaluate the hepatoprotective potential of α-lactalbumin (αLA) against dimethylnitrosamine (DMN)-induced toxic insults in the rat liver. The liver damage was induced in rats by the repeated administration of DMN (10 mg/kg, i.p.) on three consecutive days per week for three weeks. The rats were maintained on either a standard AIN-93 M or αLA-enriched diet starting one week before the DMN injection until the termination of the experiment. The DMN treatment produced a progressive increase in the plasma markers (aspartate aminotransferase, alanine aminotransferase, total bililbin, hyarulonic acid, and matrix metalloproteinase-2) in 28 days after the first DMN injection. Dietary treatment with αLA significantly reduced the DMN-induced damage toward normalcy. N^Ｇ-nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor, significantly attenuated the hepatoprotective effect of αLA. These findings show that αLA has a marked suppressive effect on hepetic fibrosis through a nitric oxide-mediated mechanism.