Oleuropein as an inhibitor of peroxisome proliferator-activated receptor gamma

• Published in: Genes & nutrition 2014-01, Vol.9 (1), p.376-376, Article 376
• Main Authors: Svobodova, Michaela, Andreadou, Ioanna, Skaltsounis, Alexios-Leandros, Kopecky, Jan, Flachs, Pavel
• Format: Article
• Language: English
• Subjects: adipocytes; beta-lactamase; cytotoxicity; fatty-acid synthase; gene expression; leaves; mice; oleuropein; olives; reporter genes; Research Paper; transcription factors; viability
• ISSN: 1555-8932; 1865-3499
• DOI: 10.1007/s12263-013-0376-0

Oleuropein, the major phenolic compound found in olive leaves and oil, exerts antioxidant, anti-inflammatory and anti-atherogenic effects and suppresses the adipocyte differentiation in vitro. Herein, we characterized molecular mechanisms underlying the anti-adipogenic effects of oleuropein on 3T3-L1 cells and adipocytes derived from stromal-vascular fraction of dorsolumbar and gonadal fat dissected from mice. We found that oleuropein (>100 μM) decreased viability of preadipocytes proliferating in vitro and did not exerted any cytotoxic effects in post-confluent cells after induction of differentiation. Oleuropein (>100 μM) inhibited adipocyte differentiation, suppressed gene expression of peroxisome proliferator-activated receptor γ (PPARγ), CCAAT-/enhancer-binding protein α, sterol regulatory element-binding transcription factor 1c and fatty acid synthase. Furthermore, we tested ability of oleuropein to regulate of PPARγ-, PPARα- or PPARβ-/PPARδ-mediated β-lactamase expression in appropriate reporter gene assays. Oleuropein between 10 and 400 μM concentrations did not affect activity of PPARα or PPARβ/δ. Contrary, PPARγ activity, either basal or rosiglitazone activated, was inhibited by oleuropein. Our data suggest that oleuropein exerts anti-adipogenic effect through direct inhibition of PPARγ transcriptional activity.