Dietary supplementation of grape polyphenols to rats ameliorates chronic ethanol-induced changes in hepatic morphology without altering changes in hepatic lipids

Increase in oxidative stress after chronic ethanol consumption can result i n hepatic injury. Because polyphenolic compounds can offer antioxidant prot ection to the cardiovascular system, this study was designed to investigate whether dietary supplementation of polyphenols from grapes may ameliorate hepatic injury resulting from chronic ethanol consumption. Male Sprague-Daw ley rats were administered the following diets for 2 mo: 1) Lieber-DeCarli (L-D) diet with isocaloric amount of maltose instead of ethanol (Basal), 2) the L-D diet with 50g/L ethanol (ROH); 3) L-D diet with 50 mg/L of grape p olyphenols (GP) and 4) ethanol diet with GP (EtOH + GP). Rats given EtOH or ROH + GP diets had significantly more hepatic triacylglycerols (P < 0.0001 ) and lipid peroxidation products (P < 0.01) compared with those given the Basal and GP diets. In addition, ethanol ingestion also decreased significa ntly (P < 0.01) the proportion of 16:0 and increased 18:0 and 18:1 in hepat ic phospholipids, suggesting a perturbation of the de novo fatty acid biosy nthesis pathways. However, GP supplementation alone and GP added to the eth anol diet did not alter the lipid changes mediated by ethanol except for th e levels of 22:6(n-3) which were significantly (P < 0.05) higher in the ROH + GP group than in the EtOH group. Despite a lack of gross lipid changes, histologic assessment showed significantly (P < 0.05) less hepatic damage i n the GP + EtOH group compared with the ROH group. These results clearly di stinguished ethanol-mediated changes in hepatic morphology from the changes in hepatic lipids and further demonstrated the ability of GP to ameliorate hepatic damage resulting from chronic ethanol consumption.