Kwak Sang Hee, Kim Yoon Hee
Department of Food and Nutrition, Daegu University, Gyeongsan, Korea.
Research Institute of Anti-Aging, Daegu University, Gyeongsan, Korea.
J Obes Metab Syndr. 2019 Jun;28(2):105-111. doi: 10.7570/jomes.2019.28.2.105. Epub 2019 Jun 30.
An excess storage of body fat causes obesity. Since obesity increases risk of chronic diseases, it is important to inhibit excessive storage of fat. Zaluzanin C is a sesquiterpene lactone isolated from . The aim of this study was to demonstrate the effect of zaluzanin C on differentiation of 3T3-L1 preadipocytes into mature adipocytes.
The cytotoxicity of zaluzanin C and its effect on cell proliferation was determined. For the induction of adipocyte differentiation, 3T3-L1 preadipocytes were treated with differentiating medium containing 10 μg/mL insulin, 115 μg/mL methylisobutylxanthine, and 1 μM dexamethasone. Differentiated 3T3-L1 cells were subjected to Oil red O solution or used for Western blot analysis. Zaluzanin C was added to the cell culture medium at concentrations of 0, 1, 2.5, 5, and 10 μM.
Zaluzanin C did not inhibit cell proliferation and showed no cytotoxicity at 10 μM concentration in 3T3-L1 cells. Therefore, concentration range of 0-10 μM zaluzanin C was used for subsequent experiments. Zaluzanin C inhibited accumulation of lipid droplets in 3T3-L1 adipocytes. To understand the underlying mechanism of zaluzanin C, expression of adipogenesis regulators was determined by Western blot analysis. Zaluzanin C suppressed peroxisome proliferator-activated receptor gamma (PPARγ) expression, an adipogenesis related transcription factor, and inhibited aP2/fatty acid-binding protein-4 expression, a target gene of PPARγ. However, it did not affect expression of CCAAT/enhancer-binding protein alpha related with acquisition of insulin sensitivity.
These data suggest that inhibitory effect of zaluzanin C on adipogenesis of 3T3-L1 adipocytes could be partially caused by suppressing PPARγ.
体内脂肪过度储存会导致肥胖。由于肥胖会增加慢性病风险，抑制脂肪过度储存很重要。扎鲁扎宁C是一种从……中分离出的倍半萜内酯。本研究的目的是证明扎鲁扎宁C对3T3-L1前脂肪细胞分化为成熟脂肪细胞的影响。
测定扎鲁扎宁C的细胞毒性及其对细胞增殖的影响。为诱导脂肪细胞分化，用含10μg/mL胰岛素、115μg/mL甲基异丁基黄嘌呤和1μM地塞米松的分化培养基处理3T3-L1前脂肪细胞。将分化的3T3-L1细胞用 Oil red O溶液处理或用于蛋白质免疫印迹分析。将扎鲁扎宁C以0、1、2.5、5和10μM的浓度添加到细胞培养基中。
扎鲁扎宁C在3T3-L1细胞中浓度为10μM时不抑制细胞增殖且无细胞毒性。因此，后续实验使用0-10μM的扎鲁扎宁C浓度范围。扎鲁扎宁C抑制3T3-L1脂肪细胞中脂滴的积累。为了解扎鲁扎宁C的潜在机制，通过蛋白质免疫印迹分析测定脂肪生成调节因子的表达。扎鲁扎宁C抑制过氧化物酶体增殖物激活受体γ（PPARγ）的表达，PPARγ是一种与脂肪生成相关的转录因子，并抑制PPARγ的靶基因aP2/脂肪酸结合蛋白-4的表达。然而，它不影响与胰岛素敏感性获得相关的CCAAT/增强子结合蛋白α的表达。
这些数据表明扎鲁扎宁C对3T3-L1脂肪细胞脂肪生成的抑制作用可能部分是由抑制PPARγ引起的。
