Monounsaturated fatty acid-enriched olive oil exacerbates chronic alcohol-induced hepatic steatosis and liver injury in C57BL/6J mice

Dietary oil composition determines the pathological processes of alcoholic fatty liver disease (AFLD). Oil rich in saturated fatty acids protects, whereas oil rich in polyunsaturated fatty acids aggravates the alcohol-induced liver injury. However, limited studies have been conducted to address how monounsaturated fatty acids (MUFAs) enriched oil controls the pathological development of AFLD. Therefore, this study was designed to evaluate the effect of MUFA-enriched extra virgin olive oil (OO) on AFLD. Twenty C57BL/6J mice were randomly allocated into four groups and fed modified Lieber-DeCarli liquid diets containing isocaloric maltose dextrin a non-alcohol or alcohol with corn oil and OO for four weeks. Dietary OO significantly exacerbated alcohol-induced liver dysfunction, evidenced by histological examinations and disturbed biochemical parameters. Dietary OO with alcohol decreased hormone-sensitive lipase (HSL), phosphorylated 5'-AMP-activated protein kinase (p-AMPK), and carnitine palmitoyltransferase-Iα (CPT1α) expression, and increased sterol regulatory element-binding protein-1c (SREBP-1c), diacylglycerol acyltransferase-2 (DGAT2), and very low-density lipoprotein receptor (VLDLR) expression in the liver. It also promoted the expression of hepatic interleukin-6 (IL-6) and hepatic tumour necrosis factor-alpha (TNF-α) at the transcriptional level. Additionally, adipose tissue lipolysis partially had an etiologic effect on alcohol-induced hepatic steatosis under OO pretreatment. In conclusion, MUFA-enriched OO exacerbated liver dysfunction in vivo. OO should be cautiously considered as a unique dietary oil source for individuals with AFLD.