木犀草素减轻氧化应激引起的血管内皮损伤

目的：探讨木犀草素对叔丁基过氧化氢致血管内皮损伤的保护作用及相关机制。方法：首先通过制备大鼠胸主动脉环,观察木犀草素对叔丁基过氧化氢所致血管张力变化的影响;再采用叔丁基过氧化氢诱导血管内皮细胞氧化损伤模型,观察木犀草素对其细胞形态学变化及细胞活力的影响,并用RT-PCR检测eNOS和COX-1 mRNA的含量变化。结果：木犀草素能够浓度依赖性地对抗叔丁基过氧化氢导致的血管舒张功能损伤及细胞损伤作用,且浓度依赖性地减弱叔丁基过氧化氢对内皮细胞eNOS mRNA表达抑制的影响。结论：木犀草素是一种有效的舒血管物质,它可以起到抗氧化的作用,减轻氧化应激反应,并可能通过维持eNOS活性等血管内皮途径舒张血管。

Luteolin ameliorates endothelial dysfunction induced by oxidative stress

AIM To evaluate the protective effect of luteolin on endothelial dysfunction induced by tert-butyl hydro-peroxide (t-BOOH). METHODS We observed the effect of luteolin on t-BOOH-induced contractions in the aorta rings with or without endot helium, which were incubated with luteolin (10-6 to 10-4 mol/L) for 30 min before determining the concentration-response to t- BOOH. Cultured endothelial cell line (ECV304) was pretreated with different concentrations of luteolin (10-6 to 10-4 mol/L) for 30 min and then exposed to 10 -5 mol/L t-BOOH for 24 hours. Cell morphology was observed , and cell viability was determined by MTT assay. Meanwhile, RT-PCR was used to measure the expression of eNOS and COX-1. RESULTS Increasing concentrations of t-BOOH produced concentration-dependent cont ractions in aorta rings isolated from rats, luteolin effectively attenuated the contraction in a concentration-dependent manner, and the relaxation response was greater in intact endothelium segments. In MTT and RT-PCR assays, luteolin effectively reduced the cytotoxicity of t-BOOH to endothelium cell and increased the expression of nitric oxide synthase (eNOS) mRNA, which was greatly down-regulated by t-BOOH. CONCLUSION Luteolin effectively protects the endothelium from the impairment of oxidative stress, and the protection could be related to its negative modulation towards t-BOOH-induced contractions in the aorta.