The effects of daily supplementation of Dendrobium huoshanense polysaccharide on ethanol-induced subacute liver injury in mice by proteomic analysis

Polysaccharides isolated from edible Dendrobium huoshanense have been shown to possess a hepatoprotection function for selenium- and carbon tetrachloride-induced liver injury. In this study, we investigated the preventive effects of daily supplementation with an homogeneous polysaccharide (DHP) purified from D. huoshanense on ethanol-induced subacute liver injury in mice and its potential mechanisms in liver protection by a proteomic approach. DHP was found to effectively depress the increased ratio of liver weight to body weight, reduce the elevated levels of serum aspartate aminotransferase, total cholesterol, total bilirubin and low density lipoprotein, and alleviate hepatic steatosis in mice with ethanol-induced subacute liver injury. Hepatic proteomics analysis performed by two-dimensional difference gel electrophoresis (2D-DIGE) coupled with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) revealed that cystathionine beta-synthase (Cbs) and D-lactate dehydrogenase (Ldhd) were two key proteins regulated by daily DHP intervention, which may assist in correcting the abnormal hepatic methionine metabolism pathway and decreasing the level of hepatic methylglyoxal generated from disordered metabolic pathways caused by ethanol. Our data suggest that DHP can protect liver function from alcoholic injury with complicated molecular mechanisms involving regulation of Cbs and Ldhd.