Liao Chung-Chia, Ou Ting-Tsz, Wu Cheng-Hsun, Wang Chau-Jong
Division of Endocrinology and Metabolism, Department of Internal Medicine, Cheng-Ching Hospital , Taichung, Taiwan.
J Agric Food Chem. 2013 Nov 20;61(46):11082-8. doi: 10.1021/jf4026647. Epub 2013 Nov 5.
This study investigated the influence of phenolic caffeic acid on obesity in mice fed a high fat diet and its underlying mechanisms base on adipose and hepatic lipid lipogenesis. C57BL/6 mice were fed a normal diet or a HFD (20% fat, w/w) with or without caffeic acid (0.02% and 0.08%, w/w) for 6 weeks. The effects of caffeic acid on hyperlipidemia, hyperglycemia, visceral fat accumulation, and related enzyme activities in HFD-mice are examined. The supplementation of caffeic acid significantly lowered body weight, visceral fat mass, plasma GOT and GPT levels, FAS activity, and free fatty acid compared to the HFD group. Caffeic acid also lowered triglyceride and cholesterol concentrations in plasma and liver. Furthermore, we showed that caffeic acid efficiently inhibited cholesterol biosynthesis as evidenced by 3-hydroxy-3-methylglutaryl CoA reductase in the liver. Caffeic acid supplementation suppressed the activity of lipogenesis via sterol regulatory element-binding protein 1 c and its target enzyme fatty acid synthase. In addition, caffeic acid resulted in increased phosphorylation of AMP-activated protein kinase and decreased acetyl carboxylase, a downstream target of AMPK, which are related to fatty acid β-oxidation in the liver. In conclusion, these results indicate that caffeic acid exhibits a significant potential as an antiobesity agent by suppression of lipogenic enzymes and hepatic lipid accumulation.
本研究基于脂肪和肝脏脂质生成,探讨了酚类咖啡酸对高脂饮食喂养小鼠肥胖的影响及其潜在机制。将C57BL/6小鼠分为正常饮食组或高脂饮食组(20%脂肪,w/w),高脂饮食组再分为添加或不添加咖啡酸(0.02%和0.08%,w/w)两组,喂养6周。检测咖啡酸对高脂饮食小鼠高脂血症、高血糖、内脏脂肪堆积及相关酶活性的影响。与高脂饮食组相比,补充咖啡酸显著降低了体重、内脏脂肪量、血浆谷草转氨酶和谷丙转氨酶水平、脂肪酸合酶活性以及游离脂肪酸。咖啡酸还降低了血浆和肝脏中的甘油三酯和胆固醇浓度。此外,我们发现咖啡酸有效抑制了肝脏中3-羟基-3-甲基戊二酰辅酶A还原酶所证明的胆固醇生物合成。补充咖啡酸通过抑制固醇调节元件结合蛋白1c及其靶酶脂肪酸合酶的活性来抑制脂肪生成。此外,咖啡酸导致肝脏中与脂肪酸β氧化相关的AMP激活蛋白激酶磷酸化增加,以及AMPK的下游靶点乙酰辅酶A羧化酶减少。总之,这些结果表明咖啡酸通过抑制脂肪生成酶和肝脏脂质积累,具有作为抗肥胖剂的显著潜力。