摘 要：探讨荷叶总黄酮对H2O2诱导的PC12细胞损伤的保护作用及机制。建立以H2O2诱导大鼠肾上腺嗜铬细胞瘤细胞（PC12）为氧化应激损伤模型，通过四甲基偶氮唑盐（MTT）比色法检测正常细胞存活率与损伤程度；试剂盒测定不同浓度荷叶总黄酮对H2O2刺激PC12细胞中超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活力、丙二醛(MDA)、蛋白质羰基含量的影响并检测Caspase-3活力的变化；Real TimePCR检测胞浆内Bcl-2与Bax的基因mRNA的表达。结果表明：荷叶总黄酮能显著提高H2O2损伤的PC12细胞存活率，显著减少H2O2刺激的PC12细胞中MDA与蛋白质羰基的生成，提高CAT活性，但对提高SOD活力不显著，PC12细胞损伤可引起凋亡相关蛋白Bax mRNA的表达增加, 加入荷叶总黄酮后有降低作用; 同时H2O2使Bcl-2 mRNA的表达降低, 加入荷叶总黄酮后有提高作用。荷叶总黄酮在给药浓度较低的情况下，对H2O2损伤的PC12细胞发挥着明显的保护作用，其作用机制可能与抑制线粒体途径的细胞凋亡有关。80050

毕业论文关键字：荷叶总黄酮；氧化应激；过氧化氢（H2O2）；PC12细胞；Caspase-3活力

Abstract：The aim of this study is to evaluate the protective effects of total flavonoids from lotus leaf ( Nelumbo nuciferea Gaertn。) on the PC12 cells injury induced by H2O2 and its mechanisms。 The oxidative stress model was establishment of H2O2 induced rata drenal pheochromocytoma cells(PC12), by tetrazolium salt (MTT)colorimetric assay survival rate and extent of damage to normal cells; the activities of superoxde dismutase (SOD), malondialdehyde (MDA) content as well as protein carbonyl content were dietermined by Determination Kit; the mRNA levels of Bcl-2 and Bax was measured by real-time PCR。 The results showed that: total flavonoids from lotus leaf can improved the viability of PC12 cells H2O2 injury, enhanced activity of superoxide dismutase and catalase, and decreased levels of malondialdehyde and protein carbonyl generation, But not significantly improve the activity of SOD, PC12 cell injury can cause apoptosis related protein Bax mRNA expression increased after adding flavonoids from lotus leaf had a reduced effect; meanwhile H2O2 made Bcl-2 mRNA expression decreased after adding flavonoids from lotus leaf effect has been improved。 Flavonoids from lotus leaf at a lower concentration, the administration of H2O2 in PC12 cells injury plays a significant protective effect, the mechanism may be related to inhibition of mitochondrial apoptosis pathway related。 

Keywords: Flavonoids from lotus leaf; oxidative stress; hydrogen peroxide (H2O2); PC12 cells; Caspase-3 vitality

目 录

1 前言 3

1。1 荷叶的应用 3

1。2 荷叶中黄酮的作用 3

2 实验材料与方法 4

2。1 实验材料 4

2。2 实验仪器 4

2。3 荷叶总黄酮提取及含量的测定[11] 4

2。3。1 荷叶总黄酮提取 4

2。3。2 芦丁标准曲线的制作[11] 4

2。3。3荷叶总黄酮含量的测定 5

2。4 PC12 细胞培养 5

2。5 荷叶总黄酮单独给药对正常 PC12细胞的影响 5

2。6 荷叶总黄酮对 PC12细胞凋亡率的影响 5

2。7 荷叶总黄酮对氧化应激的PC12细胞中SOD、Cat活力以及MDA/蛋白质羰基含量的影响 5