Pyropia yezoensis glycoprotein regulates antioxidant status and prevents hepatotoxicity in a rat model of D-galactosamine/lipopolysaccharide-induced acute liver failure

Abstract

The present study aimed to investigate the effects of Pyropia yezoensis glycoprotein (PYGP) on hepatic antioxidative enzyme activity and mitogen-activated protein kinase (MAPK) phosphorylation in a rat model of D-galactosamine/lipopolysaccharide (D-GalN/LPS)-induced hepatotoxicity. Glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) were measured to determine the severity of hepatotoxicity. Treatment with D-GalN/LPS significantly increased the GOT, GPT and lipid peroxidation levels, and decreased the antioxidant capacity of the rats. Treatment with PYGP (150 and 300 mg/kg/body weight) decreased the levels of GOT, GPT and lipid peroxidation levels. The activities of antioxidative enzymes, including catalase, glutathione S-transferase and glutathione were upregulated following PYGP treatment. Furthermore, D-GalN/LPS-induced MAPK phosphorylation, and inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression were downregulated by PYGP. These results indicated that PYGP may exert hepatoprotective effects via the upregulation of antioxidative enzymes, and the downregulation of the MAPK signaling pathway and iNOS and COX-2 expression.