■非甾体抗炎药(NSAIDs),如双氯芬酸(DCF),形成一组重要的环境污染物。当分析DCF对植物的毒性作用时,作者经常关注光合作用,而线粒体呼吸通常被忽视。因此,需要对DCF处理下的植物线粒体功能进行体内研究。在目前的工作中,我们决定使用绿藻莱茵衣藻作为模型生物。
■用浓度为135.5mg×L-1的DCF处理莱茵衣藻菌株CC-1690的同步培养物,对应于毒理学值EC50/24。为了评估短期暴露于DCF对线粒体活性的影响,耗氧率,分析线粒体膜电位(MMP)和线粒体活性氧(mtROS)的产生。为了抑制细胞色素C氧化酶或替代氧化酶活性,使用氰化钾(KCN)或水杨羟胺酸(SHAM),分别。此外,使用共聚焦显微镜和透射电子显微镜分析细胞的结构组织。
■结果表明,短期暴露于DCF会导致耗氧率增加,与对照相比,处理群体中的细胞伴随着低MMP和减少的mtROS产生。这些观察结果表明,由于线粒体膜的破坏,氧化磷酸化的解偶联,这与电子显微照片中观察到的线粒体结构畸形一致,如伸长率,不规则的形式,和降解的cr,可能表明线粒体肿胀或裂变过度。通过将DCF处理的细胞中的线粒体参数与用选择性呼吸抑制剂处理的细胞中的相同参数进行比较,进一步支持关于非特异性DCF作用的假设:在实验变体之间没有发现相似性。
■这项工作中获得的结果表明,DCF强烈影响经历轻度代谢或发育障碍的细胞,在控制条件下没有透露,虽然更多的生命细胞只受到轻微的影响,正如文献中已经指出的那样。在遭受DCF治疗的细胞中,药物以非特异性方式影响线粒体功能,破坏线粒体膜的结构.这种主要作用可能导致线粒体内膜通透性转变和氧化磷酸化的解偶联。可以认为线粒体功能障碍是DCF植物毒性的重要因素。由于NSAIDs对植物线粒体功能影响的研究相对较少,本研究对阐明NSAID对非靶标植物生物的毒性机制有重要贡献。
UNASSIGNED: Non-steroidal anti-inflammatory drugs (NSAIDs), such as diclofenac (DCF), form a significant group of environmental contaminants. When the toxic effects of DCF on plants are analyzed, authors often focus on photosynthesis, while mitochondrial respiration is usually overlooked. Therefore, an in vivo investigation of plant mitochondria functioning under DCF treatment is needed. In the present work, we decided to use the green alga Chlamydomonas reinhardtii as a model organism.
UNASSIGNED: Synchronous cultures of Chlamydomonas reinhardtii strain CC-1690 were treated with DCF at a concentration of 135.5 mg × L-1, corresponding to the toxicological value EC50/24. To assess the effects of short-term exposure to DCF on mitochondrial activity, oxygen consumption rate, mitochondrial membrane potential (MMP) and mitochondrial reactive oxygen species (mtROS) production were analyzed. To inhibit cytochrome c oxidase or alternative oxidase activity, potassium cyanide (KCN) or salicylhydroxamic acid (SHAM) were used, respectively. Moreover, the cell\'s structure organization was analyzed using confocal microscopy and transmission electron microscopy.
UNASSIGNED: The results indicate that short-term exposure to DCF leads to an increase in oxygen consumption rate, accompanied by low MMP and reduced mtROS production by the cells in the treated populations as compared to control ones. These observations suggest an uncoupling of oxidative phosphorylation due to the disruption of mitochondrial membranes, which is consistent with the malformations in mitochondrial structures observed in electron micrographs, such as elongation, irregular forms, and degraded cristae, potentially indicating mitochondrial swelling or hyper-fission. The assumption about non-specific DCF action is further supported by comparing mitochondrial parameters in DCF-treated cells to the same parameters in cells treated with selective respiratory inhibitors: no similarities were found between the experimental variants.
UNASSIGNED: The results obtained in this work suggest that DCF strongly affects cells that experience mild metabolic or developmental disorders, not revealed under control conditions, while more vital cells are affected only slightly, as it was already indicated in literature. In the cells suffering from DCF treatment, the drug influence on mitochondria functioning in a non-specific way, destroying the structure of mitochondrial membranes. This primary effect probably led to the mitochondrial inner membrane permeability transition and the uncoupling of oxidative phosphorylation. It can be assumed that mitochondrial dysfunction is an important factor in DCF
phytotoxicity. Because studies of the effects of NSAIDs on the functioning of plant mitochondria are relatively scarce, the present work is an important contribution to the elucidation of the mechanism of NSAID toxicity toward non-target plant organisms.