Protective Effects of Glycoprotein from Porphyra yezoensis against Alcohol-Induced Chronic Stomach Injury in Rats

Abstract

This study examined the protective effects of dietary glycoproteins of Porphyrayezoensis (PY-GP) against ethanol (EtOH) -induced stomach damage using in vivo assay in rat. A porphyra-originated glycolprotein was extracted using consecutive processes of water and ethanol treatment. A total of 20 male rats were distributed into 20 polypropylene cages in groups of 5, and each cage was then randomly assigned to one of five replicates of four treatments containing control, ethanol (3.7 g/kg), and ethanol co-treatment with low-dose (150 mg/ml) and high-dose (300 mg/ml) of PY-GP. The rats fed withcommercial diet and were allowed free access to water during the experiment period. Results based on western blot analysis indicated that, PY-GP dose-dependently decreased the expression of pro-apoptotic proteins BAD, BAX, Cytochrome c, and cleaved caspase-3 and -9, as well as increased the levels of anti-apoptotic protein Bcl-2. In addition, co-treatment with PY-GP and EtOH decreased phospho-JNK, ERK, p38 and Shc activation,and increased p-AKT activation. JNK, ERK, p38 and AKT were not different among treatments. Therefore, the results showed that PY-GP may effectively ameliorate ethanol-induced stomach damage and could be a novel treatment for gastric damages in humans.