Endogenously elevated n-3 polyunsaturated fatty acids alleviate acute ethanol-induced liver steatosis

Abstract

Effective means for the prevention of alcohol-induced liver disease, a global health problem, have yet to be developed. We evaluated whether the high endogenous levels of omega-3 polyunsaturated acids (n-3 PUFA) in fat-1 transgenic mice could protect them against acute ethanol-induced liver steatosis. We induced alcoholic liver steatosis in 9-week-old male heterozygous fat-1 mice and their wild-type (WT) male littermates through three oral gavages of 60% ethanol at 4.7 g/kg body weight. Hepatic lipid accumulation was significantly increased in both alcohol treatment groups, but by much less in the fat-1 group compared with the WT group. Fat-1 mice exhibited significantly lower levels of total hepatic/plasma TG and plasma alanine aminotransferase activity. Accordingly, hepatic expression of lipogenesis-related genes (e.g., SREBP-1c, FAS, and SCD-1) and plasma levels of inflammatory cytokines (e.g., IL-6, TNF-α, and MCP-1) were reduced in the fat-1 mice. Furthermore, decreased hepatic expression of cytochrome P450 2E1 (CYP2E1) and increased hepatic levels of PPAR-α and HO-1 were observed in the fat-1 mice, compared to the WT mice. These findings show that elevated tissue n-3 PUFA protect against acute ethanol-induced liver steatosis in fat-1 mice, possibly through the down-regulation of hepatic lipogenesis, inflammatory response, and oxidative stress.

Keywords: alcoholic liver steatosis; fat-1 mice; lipid metabolism; n-3 PUFA; oxidative stress.