Began G, Sudharshan E, Appu Rao A G
Department of Protein Chemistry and Technology, Central Food Technological Research Institute, Mysore, India.
Lipids. 1998 Dec;33(12):1223-8. doi: 10.1007/s11745-998-0327-2.
Curcumin (diferuloyl methane) from rhizomes of Curcuma longa L. binds to phosphatidylcholine (PC) micelles. The binding of curcumin with PC micelles was followed by fluorescence measurements. Curcumin emits at 490 nm with an excitation wavelength of 451 nm after binding to PC-mixed micelles stabilized with deoxycholate. Curcumin in aqueous solution does not inhibit dioxygenation of fatty acids by Lipoxygenase 1 (LOX1). But, when bound to PC micelles, it inhibits the oxidation of fatty acids. The present study has shown that 8.6 microM of curcumin bound to the PC micelles is required for 50% inhibition of linoleic acid peroxidation. Lineweaver-Burk plot analysis has indicated that curcumin is a competitive inhibitor of LOX1 with Ki of 1.7 microM for linoleic and 4.3 microM for arachidonic acids, respectively. Based on spectroscopic measurements, we conclude that the inhibition of LOX1 activity by curcumin can be due to binding to active center iron and curcumin after binding to the PC micelles acts as an inhibitor of LOX1.
姜黄（Curcuma longa L.）根茎中的姜黄素（二阿魏酰甲烷）与磷脂酰胆碱（PC）胶束结合。通过荧光测量追踪姜黄素与PC胶束的结合情况。姜黄素与用脱氧胆酸盐稳定的PC混合胶束结合后，在激发波长为451 nm时于490 nm处发射荧光。水溶液中的姜黄素不抑制脂氧合酶1（LOX1）对脂肪酸的双加氧作用。但是，当与PC胶束结合时，它会抑制脂肪酸的氧化。本研究表明，50%抑制亚油酸过氧化需要8.6微摩尔与PC胶束结合的姜黄素。Lineweaver - Burk作图分析表明，姜黄素是LOX1的竞争性抑制剂，对亚油酸的抑制常数Ki为1.7微摩尔，对花生四烯酸的抑制常数Ki为4.3微摩尔。基于光谱测量，我们得出结论，姜黄素对LOX1活性的抑制可能是由于其与活性中心铁结合，且姜黄素与PC胶束结合后作为LOX1的抑制剂发挥作用。
