Departamento de Ciências Farmacêuticas, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, CEP 88040-900, Florianópolis, SC, Brazil.
Toxicol In Vitro. 2011 Dec;25(8):2025-34. doi: 10.1016/j.tiv.2011.08.003. Epub 2011 Aug 12.
This study investigated the mechanism of cytotoxicity of octyl (G8) and dodecyl (G12) gallates in a murine melanoma cell line (B16F10). For this purpose, several methods to measure cell viability were used to determine if the cytotoxicity induced by these gallates corresponds to a general or an organelle-specific effect. Furthermore, the mechanisms related to apoptosis were examined, by studying the caspase-3 activity, oxidative stress, mitochondrial potential and the expression of anti- or proapoptotic proteins. When comparing the various methods of assessing cell viability, the tested gallates showed a higher cytotoxicity in the assay that indicates lysosomal activity, compared with the assays that indicate mitochondrial and ribosomal activities. Both gallates promoted the release of lactate dehydrogenase into the medium, indicating an effect on cell membrane integrity. The gallates also promoted cellular oxidative stress, mitochondrial depolarization and an increase in caspase-3 activity. Furthermore, the gallates induced an increase in proapoptotic (Bax) and a decrease in antiapoptotic (Bcl-2) proteins expression. Our results indicate that the apoptotic cell death induced by G8 and G12 in B16F10 cells involves lipid membrane damages, lysosomal and mitochondrial dysfunction, which was accompanied by alterations in apoptotic proteins expression and seems to be triggered by cellular oxidative stress.
本研究探讨了辛基（G8）和十二烷基（G12）没食子酸酯在小鼠黑色素瘤细胞系（B16F10）中的细胞毒性机制。为此，使用了几种测量细胞活力的方法来确定这些没食子酸酯诱导的细胞毒性是否对应于一般的或细胞器特异性的效应。此外，还通过研究 caspase-3 活性、氧化应激、线粒体膜电位和抗凋亡或促凋亡蛋白的表达，研究了与凋亡相关的机制。在比较评估细胞活力的各种方法时，与指示线粒体和核糖体活性的测定相比，测试的没食子酸酯在指示溶酶体活性的测定中显示出更高的细胞毒性。两种没食子酸酯都促进了乳酸脱氢酶向培养基中的释放，表明对细胞膜完整性有影响。没食子酸酯还促进了细胞氧化应激、线粒体去极化和 caspase-3 活性的增加。此外，没食子酸酯诱导了促凋亡蛋白（Bax）的增加和抗凋亡蛋白（Bcl-2）的减少。我们的结果表明，G8 和 G12 在 B16F10 细胞中诱导的细胞凋亡死亡涉及脂膜损伤、溶酶体和线粒体功能障碍，这伴随着凋亡蛋白表达的改变，似乎是由细胞氧化应激引发的。
