Oleic acid and olive oil polyphenols downregulate fatty acid and cholesterol synthesis in brain and liver cells

Abstract Extra virgin olive oil (EVOO) significantly contributes to human health. Bioactive components of EVOO are oleic acid (OA) and phenolic compounds with high antioxidant activity. In primary cultures of rat hepatocytes, hydroxytyrosol (HTyr), tyrosol, and oleuropein, the main EVOO phenols, significantly reduce both de novo lipogenesis (DNL) and cholesterol synthesis by affecting the activities of acetyl-CoA carboxylase (ACC) and 3-hydroxy-3-methyl glutaryl-CoA reductase (HMGCR), key enzymes of DNL and cholesterol synthesis, respectively. The same inhibitory effect on lipid synthesis in hepatocytes was reported by EVOO extracts with high phenol content. Findings in experimental animals and humans highlight hypolipidemic and antisteatotic actions of EVOO phenols in nonalcoholic fatty liver disease, the most common chronic liver disease in western countries. Moreover, HTyr and OA, the latter representing the main fatty acid in EVOO, decrease fatty acid and cholesterol synthesis in a glioblastoma cell line model by inhibiting ACC and HMGCR activity and expression.