SCOPE: We evaluated the protective effect of extra virgin olive oil (EVOO) in high-fat diets (HFDs) on the inflammatory response and liver damage in a non-alcoholic fatty liver disease (NAFLD) mouse model.
METHODS AND RESULTS: C57BL/6J mice fed a standard diet or a lard-based HFD (HFD-L) for 12 weeks to develop NAFLD. HFD fed mice were then divided into four groups and fed for 24 weeks with: HFD-L; HFD-EVOO; HFD-OL (phenolics-rich EVOO) and R (reversion; standard diet). HFD-L-induced metabolic disorders were alleviated by replacement of lard with EVOO. EVOO diets improved plasma lipid profile and reduced body weight (BW), plasma and epididymal fat INF-γ, IL-6 and leptin levels and macrophage infiltration. Moreover, NAFLD Activity (NAS) scores were reduced. The liver lipid composition showed an increase in MUFAs, especially oleic acid, and a decrease in saturated fatty acids (SFAs). Hepatic adiponutrin and Cd36 gene expression was up-regulated in the EVOO groups. Liver Ingenuity pathway analysis (IPA) revealed in EVOO groups regulation of proteins involved in lipid metabolism, small molecule biochemistry, gastrointestinal disease and liver regeneration.
CONCLUSION: Dietary EVOO could repair HFD-induced hepatic damage, possibly via an anti-inflammatory effect in adipose tissue and modifications in the liver lipid composition and signaling pathways.
EJR, LMV, AL and GB laboratory work. LMV, RGD, EMF and BR data analysis and
critical revision. FM, BS and MRG study design. LM and FM wrote the manuscript. FM sourced funding. Authors marked with an asterisk shared co-first authorship. This study was supported by grants AGL2014-54585-R (Ministerio de Economía y Competitividad) and PAI-BIO311 (Junta de Andalucía). LMV is funded by Fondo Europeo de Desarrollo Regional (FEDER).
The authors have no conflict of interest
- Extra virgin olive oil (EVOO)
- high-fat diet
- nonoalcholic fatty liver disease