洋葱总黄酮透过血脑屏障抑制脑胶质瘤的作用研究

The study of flavanoids extracted from onion by two methods permeating through blood-brain barrier and their repression effects on the viability of U251 cells

目的:研究采用热水浸提和乙醇冷浸两种方法从洋葱中提取的总黄酮对血脑屏障(BBB)透过作用以及对人脑胶质母细胞瘤U251细胞增殖和凋亡的影响。方法:共培养原代鼠脑微血管内皮细胞(BMVEC)和星形胶质细胞(AC),建立血脑屏障(BBB)体外模型,通过透射电子显微镜观察和跨膜电阻值(TEER)测量验证;采用高效液相色谱(HPLC)检测黄酮类提取物对血脑屏障的透过率。两组提取物分别处理U251细胞,MTT法观察细胞的增殖抑制、彗星电泳(SCGE)分析DNA损伤及流式细胞术(FCM)分析细胞周期分布情况。结果:透射电镜及跨膜电阻仪鉴定BBB体外模型构建成功;HPLC检测证实两组黄酮类提取物尤其是乙醇冷浸法产物能有效透过血脑屏障;该提取物80μmol/L浓度即对人胶质母细胞瘤U251细胞有明显的增殖抑制及凋亡诱导作用,并使U251细胞阻滞于G2/M细胞周期检查点。结论:采用乙醇冷浸法从洋葱中提取的黄酮类物质可有效透过血脑屏障,并对人胶质母细胞瘤U251细胞有明显的增殖抑制及凋亡诱导作用。

Objective：The penetration capability through blood-brain barrier and effects on U251 proliferation and apoptosis of flavanoids extracted from onion by two different methods are investigated.Methods：Co-cultured primary brain microvessel endothelial cells（BMVEC） and astroglia cells（AC） to establish the BBB（brain-blood-barrier） model.The model was indentified by TEM（transmission electron microscopy） and TEER（Trans Epithelial Electric Resistance）.HPLC（High Pressure Liquid Chromatography） was applied to test flavanoids permeability.Meanwhile U251 cells were exposed to flavanoids for MTT assay,SCGE（Single-Cell Gel Electrophoresis） and FCM（flow flow cytometry） to analysis cell proliferation,DNA damage and cell cycle distribution.Results：We confirmed that the BBB was constructed successfully and flavanoids could permeate through the BBB effectively.The proliferation of U251 was attenuated and apoptosis was induced.Flow cytometry revealed that U251 cells were inhibited at G2/M checkpoint.Conclusion：The flavanoids extracted from onion can percolate through the BBB,restrain U251 cells proliferation and induce their apoptosis.