菊花防护晶状体上皮细胞氧化损伤及信号转导机制的实验研究

目的通过菊花影响过氧化氢（H2O2）氧化损伤的晶状体上皮细胞（LEC）内钙（Ca^2＋）、环磷酸腺苷（cAMP）、环磷酸鸟苷（cGMP）信号转导的实验研究，探讨归肝经明目中药防治白内障的细胞和分子机制。方法将传代培养的牛LEC与H2O2共同孵育复制氧化损伤模型，同时加入菊花水提取液孵育后，四甲基偶氮唑蓝法（MTT）检测LEC活性、荧光分光光度法检测LEC内的钙离子浓度（Ca^2＋]i）、放射免疫分析法检测LEC内cAMP和cGMP含量，探讨不同浓度菊花及孵育12h、24h和36h的影响。结果①H2O2组LEC活性下降，菊花使氧化损伤的LEC活性显著增高（P〈0．01），呈浓度依赖关系和时间依赖关系。（②H2O2组LEC的Ca^2＋]i升高，菊花使氧化损伤所致的LEC的Ca^2＋]i显著降低（P〈0.01），并呈时间-效应关系。③H2O2组LEC的cAMP浓度升高、cGMP浓度下降，菊花可使氧化损伤的LEC的cAMP水平显著降低（P〈0．01）、cGMP水平显著升高（P〈0．01），也呈时间-效应关系。结论通过Ca^2＋]i、cAMP和cGMP信号转导系统及其相互作用调节生物学效应，可能是菊花防护LEC氧化损伤及减少细胞凋亡的细胞和分子生物学机制。

Experimental Study on Protection of Flos Chrysanshemi against Oxidative Damages of Lens Epithelial Cell and Its Mechanism of Signal Transduction

Objective To investigate the prevention of Flos Chrysanshemi(FC)on lens epithelial cell(LEC)damaged by oxidative stress and the mechanism of signal transduction.Methods Sub-cultured bovine LEC were incubated with hydrogen peroxide(H_2O_2)and deferent concentrations of FC(0.8 mg/ml,0.4 mg/ml,0.2 mg/ml)for 12 h,24 h and 36 h respectively.The LEC activities were observed by methyl thiazolyl tetrazolium assay(MTT).LECCa~(2+)]_i were detected by spectrofluorophotometer,intracellular cyclic adenosine monophospha...