Mechanisms of Drug Toxicity Group, Pharmaceutical Sciences Institute, Aston University, Aston Triangle, Birmingham B4 7ET, UK.
Environ Toxicol Pharmacol. 2004 Jul;17(3):143-8. doi: 10.1016/j.etap.2004.04.002.
A series of antioxidants was used to explore the cytotoxicity of one particularly toxic antimycobacterial 2-pyridylcarboxamidrazone anti-tuberculosis agent against human mononuclear leucocytes (MNL), in comparison with isoniazid (INH) to aid future compound design. INH caused a significant reduction of nearly 40% in cell recovery compared with control (P < 0.0001), although the co-incubation with either glutathione (GSH, 1mM) or (NAC, 1mM) showed abolition of INH toxicity. In contrast, the addition of GSH or NAC 1h after INH failed to protect the cells from INH toxicity (P < 0.0001). The 2-pyridyl-carboxamidrazone 'Compound 1' caused a 50% reduction in cell recovery compared with control (P < 0.001), although this was abolished by the presence of either GSH or NAC. A 1h post incubation with either NAC or GSH after Compound 1 addition failed to protect the cells from toxicity (P < 0.001). Co-administration of lipoic acid (LA) abolished Compound 1-mediated toxicity, although again, this effect did not occur after LA addition 1h post incubation with Compound 1 (P < 0.001). However, co-administration of dihydrolipoic acid (DHLA) prevented Compound 1-mediated cell death when incubated with the compound and also after 1h of Compound 1 alone. Pre-treatment with GSH, then removal of the antioxidant resulted in abolition of Compound 1 toxicity (vehicle control, 63.6 ± 16.7 versus Compound 1 alone 26.1 ± 13.6% versus GSH pre-treatment, 65.7 ± 7.3%). In a cell-free incubation, NMR analysis revealed that GSH does not react with Compound 1, indicating that this agent is not likely to directly deplete membrane thiols. Compound 1's MNL toxicity is more likely to be linked with changes in cell membrane conformation, which may induce consequent thiol depletion that is reversible by exogenous thiols.
使用一系列抗氧化剂来研究一种特别有毒的抗分枝杆菌 2-吡啶甲酰胺腙抗结核药物对人单核白细胞（MNL）的细胞毒性，与异烟肼（INH）进行比较，以帮助未来的化合物设计。与对照相比，INH 导致细胞回收减少近 40%（P < 0.0001），尽管与谷胱甘肽（GSH，1mM）或（NAC，1mM）共孵育可消除 INH 毒性。相比之下，在 INH 后 1 小时添加 GSH 或 NAC 未能保护细胞免受 INH 毒性（P < 0.0001）。与对照相比，2-吡啶甲酰胺腙“化合物 1”导致细胞回收减少 50%（P < 0.001），尽管这被 GSH 或 NAC 的存在所消除。在添加化合物 1 后 1 小时用 NAC 或 GSH 孵育 1 小时后，未能保护细胞免受毒性（P < 0.001）。虽然添加 LA 后也未能阻止 1 小时后与化合物 1 共孵育时 LA 对化合物 1 介导的毒性的影响，但 LA 可消除化合物 1 介导的毒性（P < 0.001）。然而，二氢硫辛酸（DHLA）的共给药可防止与化合物 1 孵育时以及单独孵育化合物 1 1 小时后细胞死亡。GSH 预处理后，然后去除抗氧化剂可消除化合物 1 的毒性（载体对照，63.6 ± 16.7 与单独化合物 1 26.1 ± 13.6% 与 GSH 预处理，65.7 ± 7.3%）。在无细胞孵育中，NMR 分析表明 GSH 不会与化合物 1 反应，表明该试剂不太可能直接耗尽膜硫醇。化合物 1 对 MNL 的毒性更可能与细胞膜构象的变化有关，这可能导致随后的硫醇耗竭，而外源性硫醇可使其逆转。
