Tueller Daniel J, Harley Jackson S, Hancock Chad R
Department of Nutrition, Dietetics, and Food Science, Brigham Young University, Provo, UT 84602, USA.
Department of Nutrition, Dietetics, and Food Science, Brigham Young University, Provo, UT 84602, USA.
Biochem Biophys Res Commun. 2017 Oct 21;492(3):368-372. doi: 10.1016/j.bbrc.2017.08.101. Epub 2017 Aug 25.
Curcumin may improve blood glucose management, but the mechanism is not fully established. We demonstrated that curcumin (40 μM) reduced the mitochondrial coupling efficiency (percentage of oxygen consumption coupled to ATP synthesis) of intact skeletal muscle cells. A 30-minute pretreatment with curcumin reduced mitochondrial coupling efficiency by 17.0 ± 0.4% relative to vehicle (p < 0.008). Curcumin pretreatment also decreased the rate of hydrogen peroxide emission by 43 ± 13% compared to vehicle (p < 0.05). Analysis of cell respiration in the presence of curcumin revealed a 40 ± 4% increase in the rate of oxygen consumption upon curcumin administration (p < 0.05 compared to vehicle). No difference in mitochondrial coupling efficiency was observed between vehicle- and curcumin-pretreated cells after permeabilization of cell membranes (p > 0.7). The interaction between curcumin and ursolic acid, another natural compound that may improve blood glucose management, was also examined. Pretreatment with ursolic acid (0.12 μM) increased the mitochondrial coupling efficiency of intact cells by 4.1 ± 1.1% relative to vehicle (p < 0.008) and attenuated the effect of curcumin when the two compounds were used in combination. The observed changes to mitochondrial coupling efficiency and hydrogen peroxide emission were consistent with the established effects of curcumin on blood glucose control. Our findings also show that changes to mitochondrial coupling efficiency after curcumin pretreatment may go undetected unless cells are assessed in the intact condition.
姜黄素可能改善血糖管理，但其机制尚未完全明确。我们证明，姜黄素（40μM）降低了完整骨骼肌细胞的线粒体偶联效率（与ATP合成偶联的氧消耗百分比）。与载体相比，姜黄素预处理30分钟使线粒体偶联效率降低了17.0±0.4%（p<0.008）。姜黄素预处理还使过氧化氢释放速率比载体降低了43±13%（p<0.05）。在存在姜黄素的情况下对细胞呼吸进行分析发现，给予姜黄素后氧消耗速率增加了40±4%（与载体相比，p<0.05）。细胞膜透化后，载体预处理组和姜黄素预处理组细胞的线粒体偶联效率没有差异（p>0.7）。我们还研究了姜黄素与熊果酸（另一种可能改善血糖管理的天然化合物）之间的相互作用。与载体相比，熊果酸（0.12μM）预处理使完整细胞的线粒体偶联效率提高了4.1±1.1%（p<0.008），并且当两种化合物联合使用时减弱了姜黄素的作用。观察到的线粒体偶联效率和过氧化氢释放的变化与姜黄素对血糖控制的既定作用一致。我们的研究结果还表明，除非在完整状态下评估细胞，否则姜黄素预处理后线粒体偶联效率的变化可能无法检测到。
