Environmental Bioprocesses Laboratory, Laboratoire mixte international (LMI-COSYS-MED), Sfax Biotechnology Center, P.O. Box 1177, Sfax, 3038, Tunisia.
Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan.
Chem Biol Interact. 2016 May 25;252:54-60. doi: 10.1016/j.cbi.2016.03.026. Epub 2016 Mar 23.
Oleuropein, which is the major compound of olive leaves, has been reported to exert several pharmacological properties, including anti-cancer, antidiabetic and anti-atherosclerotic activities. The objective of this study was to evaluate the effect of oleuropein on adiponectin level in high cholesterol diet (HCD) induced obesity in rat and the molecular mechanism underlying its activation. Our results showed that orally administered oleuropein (50 mg/kg) by gavage for 8 weeks decreased the body weight, adipose tissue mass and triglyceride and attenuated steatosis in liver. Moreover, the effect of oleuropein on adiponectin, an important hormone with fatty-acid oxidation properties, was evaluated and our data illustrated that oleuropein supplementation increased serum adiponectin concentration. The effects of oleuropein on protein expression related to lipogenic genes were investigated and our results showed that its administration significantly inhibited peroxisome proliferator-activated receptor γ (PPARγ), sterol regulatory element-binding protein-1c (SREBP-1c) and fatty-acid synthase (FAS). In addition, oleuropein stimulated the HCD-induced inhibition of AMP-activated protein kinase (AMPK) in epididymal adipose tissues. These results suggest that oleuropein exerts anti-obesity effects in HCD rats by activating AMPK and suppressing PPAR γ (Peroxisome proliferator-activated receptor γ) expression in adipose tissues. These data provide that oleuropein has important implications for preventing obesity.
橄榄叶中的主要化合物橄榄苦苷，已被报道具有多种药理活性，包括抗癌、抗糖尿病和抗动脉粥样硬化作用。本研究旨在评估橄榄苦苷对高胆固醇饮食（HCD）诱导肥胖大鼠脂联素水平的影响及其激活的分子机制。我们的结果表明，灌胃给予橄榄苦苷（50mg/kg）8 周可降低体重、脂肪组织质量和甘油三酯，并减轻肝脏脂肪变性。此外，还评估了橄榄苦苷对脂联素的作用，脂联素是一种具有脂肪酸氧化特性的重要激素，我们的数据表明，橄榄苦苷补充剂增加了血清脂联素浓度。研究了橄榄苦苷对与脂肪生成基因相关的蛋白质表达的影响，结果表明，其给药可显著抑制过氧化物酶体增殖物激活受体 γ（PPARγ）、固醇调节元件结合蛋白-1c（SREBP-1c）和脂肪酸合成酶（FAS）。此外，橄榄苦苷还刺激了 HCD 诱导的附睾脂肪组织中 AMP 激活蛋白激酶（AMPK）的抑制。这些结果表明，橄榄苦苷通过激活 AMPK 和抑制脂肪组织中 PPARγ（过氧化物酶体增殖物激活受体 γ）的表达，对 HCD 大鼠发挥抗肥胖作用。这些数据表明，橄榄苦苷在预防肥胖方面具有重要意义。
