【摘要】 [目的]探讨姜黄素对人结肠癌HT-29细胞线粒体DNA(mtDNA)和核DNA(nDNA)的氧化损伤作用。[方法]人结肠癌HT-29细胞暴露于不同浓度姜黄素(0、5、10、20μg/ml)2h后,细胞免疫组化分析nDNA和mtDNA的8-羟基脱氧鸟苷(8-OHdG)水平;2’,7’-二氢二氯荧光比色法测定细胞内活性氧(ROS)水平;硫代巴比妥酸法测定细胞内脂质过氧化产物。[结果]随着姜黄素剂量的增高,mtDNA和nDNA的8-OHdG染色密度均增大,20μg/ml姜黄素组,胞浆的染色密度增长了15倍,核染色密度增长了6倍,表明胞浆中mtDNA的8-OHdG水平的增长明显高于nDNA,差异有统计学意义(P﹤0.05);5μg/ml以上剂量姜黄素能引起细胞的ROS水平升高和脂质过氧化产物增加(P﹤0.05或P﹤0.01)。[结论]姜黄素能引起HT-29细胞的ROS增加,并造成脂质和DNA的氧化性损伤,并且mtDNA的损伤明显大于nDNA的损伤。更多还原

【Abstract】 [Objective] To investigate the effects of curcumin on the formation of 8-Hydroxydeoxyguanosine(8-OHdG) in mitochondrial DNA(mtDNA) and nuclear DNA(nDNA) in human colon cancer cell line HT-29. [Methods] After HT-29 cells were exposed to various concentrations of curcumin(0,5,10,and 20μg /ml) for 2h,immunocytochemistry staining of 8-OHdG was performed to determine the oxidative damage to mtDNA and nDNA. The production of reactive oxygen species(ROS) was measured using the 2,7-dichlorofluorescein diacetate(DCFH-DA) method. Lipid peroxidation was determined by measurement of thiobarbituric acid-reactive substances(TBARS) . [Results] Exposure of HT-29 cells to curcumin led to a dose-dependent increase in the staining intensity of 8-OHdG in both mtDNA and nDNA. The staining intensity of 8-OHdG increased more in the mtDNA than in the nDNA,giving a 15-fold increase in 8-OHdG staining in mtDNA between 20μg /ml and control compared to a 6-fold increase in nDNA staining. The level of ROS and TBARS were significantly increased(P﹤0.05 or P﹤0.01) when HT-29 cells were treated with curcumin. [Conclusion] These data suggest that curcumin could increase the ROS formation and induce oxidative damage to lipid and both mtDNA and nDNA,and the damage to mtDNA was more significant than to nDNA in HT-29 cells.更多还原