Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université Catholique de Louvain (UCLouvain), Avenue Mounier 73.08, B-1200 Brussels, Belgium.
Molecules. 2023 Oct 10;28(20):7013. doi: 10.3390/molecules28207013.
Fungicides are widely used in agriculture for crop protection. Succinate dehydrogenase inhibitors (SDHIs) and strobilurins inhibit mitochondria electron transport chain (ETC) in fungi, by blocking complex II and complex III, respectively. Questions regarding their selectivity of action for fungi have been raised in the literature, and we previously showed that boscalid and bixafen (SDHIs) alter the mitochondrial function of human hepatocytes. Here, we analyzed the impact of the exposure of human hepatocytes to pyraclostrobin, a fungicide belonging to the class of strobilurins. Using electron paramagnetic resonance (EPR), we observed a decrease in oxygen consumption rate (OCR) and an increase in mitochondrial superoxide levels after 24 h exposure to 0.5 µM concentration. As a consequence, the content in ATP amount in the cells was reduced, the ratio reduced/oxidized glutathione was decreased, and a decrease in cell viability was observed using three different assays (PrestoBlue, crystal violet, and annexin V assays). In addition, as SDHIs and strobilurins are commonly associated in commercial preparations, we evaluated a potential "cocktail" toxic effect. We selected low concentrations of boscalid (0.5 µM) and pyraclostrobin (0.25 µM) that did not induce a mitochondrial dysfunction in liver cells when used separately. In sharp contrast, when both compounds were used in combination at the same concentration, we observed a decrease in OCR, an increase in mitochondrial superoxide production, a decrease in the ratio reduced/oxidized glutathione, and a decrease in cell viability in three different assays.
杀菌剂广泛用于农业作物保护。琥珀酸脱氢酶抑制剂 (SDHI) 和 strobilurins 通过分别阻断复合物 II 和复合物 III 来抑制真菌的线粒体电子传递链 (ETC)。关于它们对真菌作用的选择性的问题已经在文献中提出，我们之前表明 boscalid 和 bixafen (SDHI) 改变了人肝细胞的线粒体功能。在这里，我们分析了人肝细胞暴露于吡唑醚菌酯（一种属于 strobilurins 类的杀菌剂）的影响。使用电子顺磁共振 (EPR)，我们观察到在 0.5 µM 浓度下暴露 24 小时后，耗氧量 (OCR) 下降和线粒体超氧化物水平增加。结果，细胞内的 ATP 含量减少，还原/氧化型谷胱甘肽的比例降低，并且使用三种不同的测定法（PrestoBlue、结晶紫和 annexin V 测定法）观察到细胞活力下降。此外，由于 SDHI 和 strobilurins 通常在商业制剂中联合使用，我们评估了潜在的“鸡尾酒”毒性效应。我们选择了低浓度的 boscalid（0.5 µM）和 pyraclostrobin（0.25 µM），当单独使用时它们不会在肝细胞中引起线粒体功能障碍。相比之下，当两种化合物以相同浓度组合使用时，我们观察到 OCR 下降，线粒体中超氧化物的产生增加，还原/氧化型谷胱甘肽的比例降低，以及三种不同测定法中的细胞活力下降。
