Ethanol consumption can lead to hepatic steatosis that contributes to late-stage liver diseases such as cirrhosis and hepatocellular carcinoma. In this study, we investigated the potential protective effect of a flavonoid, luteolin, on ethanol-induced fatty liver development and liver injury. Six-wk-old male C57BL/6 mice were divided into 3 groups: a control group; a group exposed to alcohol by using a chronic and binge ethanol feeding protocol (EtOH); and a group that was administered daily 50 mg/kg of luteolin in addition to ethanol exposure (EtOH + Lut). A chronic and binge ethanol feeding protocol was used, including chronic ethanol consumption (1%, 2%, and 4% for 3 d, and 5% for 9 d) and a binge (30% ethanol) on the last day. Compared with the control group, the EtOH group had a significant elevation in serum concentrations of alanine aminotransferase (ALT) (561%), triglyceride (TG) (47%), and LDL cholesterol (95%), together with lipid accumulation in the, liver. Compared with the EtOH group, the EtOH + Lut group had significant reductions in serum concentrations of ALT (43%), TG (22%), LDL cholesterol (52%), and lipid accumulation in the liver. Ethanol elevated liver expression of lipogenic genes including sterol regulatory element-binding protein 1c (Srebp1c) (560%), fatty acid synthase (Fasn) (190%), acetylCoA carboxylase (Acc) (48%), and stearoyl-CoA desaturase 1 (Scd1) (286%). Luteolin reduced ethanol-induced expression of these genes in the liver: Srebp1c (79%), Fasn (80%), Acc (60%), and Scd1 (89%). In cultured hepatocytes, luteolin prevented alcohol-induced lipid accumulation and increase in the expression of lipogenic genes. The transcriptional activity of the master regulator of lipid synthesis, sterol regulatory element-binding protein (SREBP), was enhanced by ethanol treatment (160%) and reduced by luteolin administration (67%). In addition, ethanol-induced reduction of AMP-activated protein kinase and SREBP-1c phosphorylation was abrogated by luteolin. Collectively, our study indicates that luteolin is effective in ameliorating ethanol-induced hepatic steatosis and injury.
[1]Shanghai Univ Tradit Chinese Med, Sch Pharm, Shanghai, Peoples R China.
[2]Chinese Acad Sci, Grad Sch, Shanghai Inst Biol Sci, Key Lab Nutr & Metab,Inst Nutr Sci, Shanghai, Peoples R China.
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