College of Life Science, Henan Normal University, Xinxiang, Henan 453007, China.
Ecotoxicol Environ Saf. 2012 Sep;83:102-7. doi: 10.1016/j.ecoenv.2012.06.013. Epub 2012 Jul 6.
The cytotoxicity of alkylmethylimidazolium-based ionic liquids on rat pheochromocytoma (PC12) cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, lactate dehydrogenase release (LDH), and acridine orange staining in the present study. Mitochondrial depolarization, DNA fragmentation, reactive oxygen species (ROS) levels, and caspase-3 activity were also determined. The results showed dose-dependent cytotoxicity of ionic liquids on PC12 cells, and the ionic liquids with longer lateral chains had stronger cytotoxicity. Additionally, we found that exposure to the ionic liquid 1-octyl-3-methylimidazolium bromide ([C(8)mim]Br) provoked cellular LDH release, increased mitochondrial depolarization, induced cellular transmogrification, nuclear shrinkage and DNA fragmentation, and promoted caspase-3 activity and ROS levels in PC12 cells. These results suggest that [C(8)mim]Br may induce PC12 cell apoptosis triggered by excessive ROS and mediated by mitochondrial depolarization and permeability transition. Our result may be helpful for illuminating the cytotoxicity mechanism of alkylmethylimidazolium-based ionic liquids and safely using them in the future.
本研究采用 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）比色法、乳酸脱氢酶释放（LDH）和吖啶橙染色法评估了烷基甲基咪唑鎓基离子液体对大鼠嗜铬细胞瘤（PC12）细胞的细胞毒性。还测定了线粒体去极化、DNA 片段化、活性氧（ROS）水平和 caspase-3 活性。结果表明，离子液体对 PC12 细胞具有剂量依赖性细胞毒性，且侧链较长的离子液体具有更强的细胞毒性。此外，我们发现暴露于离子液体 1-辛基-3-甲基咪唑溴化盐（[C8mim]Br）会引起细胞 LDH 释放增加、线粒体去极化、细胞形态变化、核收缩和 DNA 片段化，并促进 PC12 细胞中 caspase-3 活性和 ROS 水平的增加。这些结果表明，[C8mim]Br 可能通过过度的 ROS 诱导 PC12 细胞凋亡，并通过线粒体去极化和通透性转换介导凋亡。我们的结果可能有助于阐明烷基甲基咪唑鎓基离子液体的细胞毒性机制，并为今后安全使用它们提供参考。
