Protective Effects of Luteolin against Amyloid β25–35-induced Toxicity on Rat Cerebral Microvascular Endothelial Cells

AimTo evaluate the effects of luteolin against amyloid beta-peptide 25–35 (Aβ25–35) on rat cerebral microvascular endothelial cells (CMECs).MethodsCMECs were isolated from Wistar rats at 3-week-old, and randomly divided into 5 groups including control group, Aβ25–35 group, 0.1, 1.0, and 10.0 μmol·L−1 luteolin groups. Cell viability was determined with MTS assay. Intracelluar ROS level and SOD activity were monitored by DCFH-DA and SOD inhibition assay, respectively. Transendothelial electrical resistance was measured using an EVOM resistance meter. γ-Glutamyl transpeptidase and alkaline phosphatase activities were detected using activity assay kits. Levels of TXA2 and PGI2 in culture medium were measured as their stable metabolites, TXB2 and 6-keto-PGF1α, by ELISA.ResultsLuteolin attenuated Aβ25–35-induced toxicity at 0.1, 1.0, and 10 μmol·L−1, inhibited intracellular ROS generation, and increased SOD activity at 1.0 and 10 μmol·L−1. Luteolin was also found to preserve CMECs barrier function, involving the alleviation of TEER reduction, the increase of characteristic enzymatic activity, and regulation of TXA2 and PGI2 secretion.ConclusionLuteolin had the ability to protect rat CMECs against Aβ25–35-induced toxicity.

摘 要目的：研究木犀草素对Aβ25-35损伤大鼠大脑微血管内皮细胞的保护作用。方法：取3周龄Wistar大鼠制备大脑微血管内皮细胞, 经过纯化, 将细胞随机分为对照组、Aβ25-35损伤组、0.1、1.0及10 μmol·L−1不同浓度木犀草素实验组。采用MTS法、DCFH-DA染色法、SOD抑制率实验分别检测细胞存活率、细胞内活性氧含量及SOD活力。通过测定跨内皮细胞电阻抗、γ-谷氨酰转肽酶、碱性磷酸酶、TXA2及PGI2稳定代谢产物含量, 观察微血管内皮细胞的功能及屏障特性。结果：木犀草素在0.1、1.0 及10 μmol·L−1浓度时, 可显著提高Aβ25-35作用后微血管内皮细胞存活率, 并抑制细胞内活性氧产生, 提高细胞内SOD活性。木犀草素亦可改善Aβ25-35作用后微血管内皮细胞的功能和屏障特性, 表现为提高跨内皮细胞电阻抗, 增加特征性酶含量, 缓解TXA2及PGI2分泌失衡。结论：木犀草素对Aβ25-35损伤大鼠大脑微血管内皮细胞具有保护作用。