Herein, we investigated the correlation between curcumin and glutathione (GSH) levels in mammalian cells using gold nanoparticles (AuNPs) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). GSH exists in high concentration in the cytosol and acts as a major antioxidant and reducing agent in organisms. Previous studies showed that curcumin, a well-known antioxidant with anti-inflammatory, anti-proliferative, and anti-carcinogenic activities, affects GSH levels in mammalian cells. However, the correlation between their levels remains controversial and has not yet been completely elucidated. This study used our recent strategy of GSH quantification, where GSH in cell lysate is captured on maleimide groups of AuNPs and analyzed using MALDI-TOF MS with isotopomer GSH (GSH*)-conjugated AuNPs as an internal standard. The comparison between GSH and GSH* relative intensities allows the quantitation of GSH in cells. In this way, GSH levels in mammalian cells were investigated after incubation with curcumin at various concentrations with or without oxidative stress. We observed that intracellular GSH levels were affected by curcumin in a concentration-dependent manner with oxidative stress; GSH levels decrease at a lower curcumin concentration, which can be recovered at increased curcumin concentrations. We also found that the GSH level increased at all curcumin concentrations after a certain incubation time. We believe our strategy can be commonly used to determine GSH levels in cells that are treated differently with various exogenous stimulants like reactive oxygen species, biofunctional natural products, and drug candidates. Graphical abstract.

中文翻译：

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姜黄素和氧化应激对细胞内谷胱甘肽水平的浓度依赖性作用的质谱研究。

本文中，我们使用金纳米颗粒（AuNPs）和基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）研究了哺乳动物细胞中姜黄素和谷胱甘肽（GSH）水平之间的相关性。GSH以高浓度存在于细胞质中，并在生物体中充当主要的抗氧化剂和还原剂。先前的研究表明，姜黄素是一种众所周知的抗氧化剂，具有抗炎，抗增殖和抗癌活性，可影响哺乳动物细胞中的GSH水平。但是，它们的水平之间的相关性仍存在争议，尚未完全阐明。这项研究使用了我们最近的GSH量化策略，其中细胞裂解液中的GSH被捕获在AuNP的马来酰亚胺基团上，并使用MALDI-TOF MS和结合了同位素同位素GSH（GSH *）的AuNP作为内标进行分析。GSH和GSH *相对强度之间的比较允许定量细胞中的GSH。以这种方式，在与姜黄素以各种浓度存在或不存在氧化应激的情况下孵育后，研究了哺乳动物细胞中的GSH水平。我们观察到姜黄素以浓度依赖的方式与氧化应激一起影响细胞内谷胱甘肽水平；姜黄素浓度较低时，谷胱甘肽水平降低，姜黄素浓度升高时可以恢复。我们还发现，在一定的孵育时间后，所有姜黄素浓度下的GSH含量都会增加。我们认为，我们的策略通常可用于确定细胞中的GSH水平，这些细胞被各种外源性兴奋剂（如活性氧，生物功能天然产物和候选药物）以不同方式处理。图形概要。