Institute of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Brno, Czech Republic.
J Agric Food Chem. 2013 Aug 21;61(33):7864-73. doi: 10.1021/jf401575a. Epub 2013 Aug 13.
Chromium Cr(III) toxicity toward chamomile metabolism and oxidative stress-related parameters after 7 days of exposure was studied. Cr preferentially accumulated in the roots and evoked extensive both dose-dependent and dose-independent increase in fluorescence signals of ROS, NO and thiols. Superoxide increased mainly at the highest Cr dose, whereas H2O2 accumulation revealed a discontinuous trend in relation to external Cr supply, and this could be owing to variation in activities of peroxidases. Glutathione and ascorbate quantification, using LC-MS/MS equipment, revealed strong stimulation despite low shoot Cr amounts. Phenolic enzyme activities, except for PAL, were depressed by Cr presence, whereas phenolic metabolites were stimulated, indicating various time dynamics. Among free amino acids, their sum and even proline decreased in the roots, whereas soluble proteins increased. Mineral nutrients showed negligible responses with only Zn and Cu being depleted in both shoots and roots. Cr staining using Cr(III)-specific (naphthalimide-rhodamine) and metal nonspecific (Phen Green) dyes indicated that the former correlated well with AAS quantification of Cr amount. Use of Phen Green is also discussed. These data indicate that Cr-induced oxidative stress is not simply a function of exposure time and applied concentration. Microscopic observations in terms of oxidative stress and chromium uptake are presented here for the first time.
研究了铬（III）在暴露 7 天后对甘菊代谢和氧化应激相关参数的毒性。铬优先积累在根部，并引发了广泛的、剂量依赖和剂量不依赖的 ROS、NO 和硫醇荧光信号的增加。超氧化物主要在最高铬剂量下增加，而 H2O2 的积累与外部铬供应呈不连续趋势，这可能是由于过氧化物酶活性的变化。使用 LC-MS/MS 设备定量测定谷胱甘肽和抗坏血酸，尽管地上部铬含量低，但仍显示出强烈的刺激作用。除 PAL 外，多酚酶活性被铬的存在所抑制，而酚类代谢物则受到刺激，表明时间动态不同。在游离氨基酸中，它们的总和甚至脯氨酸在根部减少，而可溶性蛋白质增加。只有锌和铜在地上部和根部都被耗尽，而矿质养分的反应可以忽略不计。使用铬（III）特异性（萘酰亚胺-罗丹明）和非特异性金属（Phen Green）染料对铬进行染色表明，前者与 AAS 定量的铬含量很好地相关。还讨论了 Phen Green 的使用。这些数据表明，铬诱导的氧化应激不仅仅是暴露时间和应用浓度的函数。本文首次就氧化应激和铬吸收的微观观察进行了讨论。
