木犀草素对脑胶质瘤细胞氨肽酶N活性影响

目的探讨木犀草素对脑胶质瘤细胞氨肽酶N活性影响机制。方法本研究采用酶抑制动力学方法, 研究了木犀草素对氨肽酶N的抑制作用、抑制类型和抑制动力学常数, 并进行了脑胶质瘤U87细胞的凋亡生长抑制试验。结果木犀草素能够诱导了脑胶质瘤U87细胞的凋亡, 并呈现一定的剂量依赖性, 当浓度≥10 μmol时, 与阳性对照bestatin 相比差异有统计意义(P<0.05), 求得半细胞凋亡率IC₅₀为(61.23±2.13)μmol;此外木犀草素是一种可逆的竞争型氨肽酶N抑制剂, 半抑制率IC₅₀为(70.85± 2.05)μmol, 抑制常数Ki为(24.83± 0.14)μmol;失活动力学时间进程分析表明,木犀草素能快速与氨肽酶N发生作用并迅速降低酶的活性。结论木犀草素是一个竞争性的氨肽酶N抑制剂, 使氨肽酶N的活性降低, 对诱导了脑胶质瘤U87细胞的凋亡起到重要作用。

Inhibitory effect of luteolin on aminopeptidase N in glioma cells and its mechanism

ObjectiveTo study inhibitory effect of luteolin on aminopeptidase N(APN)in glioma cells and its mechanism.MethodsEnzyme inhibitory kinetics was adopted to analyze the inhibitory effect and the kinetic constant of luteolin on APN.Growth inhibition test was conducted to assess the apoptosis of U87 glioma cells.ResultsAs a competitive inhibitor of APN,luteolinn could induced apootosis in U87 glioma cells,with a half inhibition concentration(IC₅₀)of 70.85 μmol/L and an inhibition constant(Ki)of 24.83 μmol/L.Inactivation time process analysis showed that mignonette element could react with APN and reduce the activity of APN rapidly.ConclusionLuteolin is a competitive APN inhibitor and could reduce the activity of APN,playing an important role in the apoptosis of U87 glioma cells.