Electrocatalytic determination of reduced glutathione in human erythrocytes

Unveiling thiol biomarkers: Glutathione and cysteamine

The physiological and clinical importance of Glutathione and Cysteamine is emphasized by their participation in a range of conditions, such as diabetes, cancer, renal failure, Parkinson's disease, and hypothyroidism. This necessitates the requirement for accessible, expedited, and cost-efficient testing that can facilitate clinical diagnosis and treatment options. This article examines numerous techniques used to detect both glutathione and cysteamine. The discussed methods include electroanalytical techniques such as voltammetry and amperometry, which are examined for their sensitivity and ability to provide real-time analysis. Furthermore, this study investigates the accuracy of gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) in measuring the concentrations of glutathione and cysteamine. Additionally, the potential of new nanotechnology-based methods, such as plasmonic nanoparticles and quantum dots, to improve the sensitivity of detecting glutathione and cysteamine is emphasized.

Fast Antioxidation Kinetics of Glutathione Intracellularly Monitored by a Dual-Wire Nanosensor

The glutathione (GSH) system is one of the most powerful intracellular antioxidant systems for the elimination of reactive oxygen species (ROS) and maintaining cellular redox homeostasis. However, the rapid kinetics information (at the millisecond to the second level) during the dynamic antioxidation process of the GSH system remains unclear. As such, we specifically developed a novel dual-wire nanosensor (DWNS) that can selectively and synchronously measure the levels of GSH and ROS with high temporal resolution, and applied it to monitor the transient ROS generation as well as the rapid antioxidation process of the GSH system in individual cancer cells. These measurements revealed that the glutathione peroxidase (GPx) in the GSH system is rapidly initiated against ROS burst in a sub-second time scale, but the elimination process is short-lived, ending after a few seconds, while some ROS are still present in the cells. This study is expected to open new perspectives for understanding the GSH antioxidant system and studying some redox imbalance-related physiological.

Versatile Construction of Biomimetic Nanosensors for Electrochemical Monitoring of Intracellular Glutathione

The current strategies for nanoelectrode functionalization usually involve sophisticated modification procedures, uncontrollable and unstable modifier assembly, as well as a limited variety of modifiers. To address this issue, we propose a versatile strategy for large-scale synthesis of biomimetic molecular catalysts (BMCs) modified nanowires (NWs) to construct functionalized electrochemical nanosensors. This design protocol employs an easy, controllable and stable assembly of diverse BMCs-poly(3,4-ethylenedioxythiophene) (PEDOT) composites on conductive NWs. The intrinsic catalytic activity of BMCs combined with outstanding electron transfer ability of conductive polymer enables the nanosensors to sensitively and selectively detect various biomolecules. Further application of sulfonated cobalt phthalocyanine functionalized nanosensors achieves real-time electrochemical monitoring of intracellular glutathione levels and its redox homeostasis in single living cells for the first time.

Voltammetric detection of glutathione: an adsorptive stripping voltammetry approach

High sensitive detection of glutathione in presence of copper(ii) ions by cyclic voltammetry using a bare glassy carbon electrode is presented.

Effect of 4-aminoantipyrine on oxidative stress induced by glutathione depletion in single human erythrocytes using a microfluidic device together with fluorescence imaging

The effects of 4-aminoantipyrine (AAP) on oxidative stress induced by glutathione (GSH) depletion in single human erythrocytes were investigated using microfluidic technique and fluorescence imaging. Most cell-based toxicity evaluations on GSH are performed with bulk experiments based on analysis of cell populations. This work established a single-cell toxicity evaluation method to statistically analyze the GSH amount in single erythrocytes incubated with AAP in different concentrations. The experimental conditions of cell flow rate and cell concentration were optimized. The GSH contents in erythrocytes decreased with increasing dose of AAP. At low concentration, AAP had a little effect on GSH; while at high concentration, AAP led to GSH depletion reaching a maximum of 14.53%. The depletion of GSH leads to a significant shift to a more oxidizing intracellular environment. This study provides basic data for presenting the effect of AAP on GSH in erythrocytes and is helpful for understanding its toxicity during the blood transportation process. In addition, it will also complement studies on the environmental risk assessment of AAP pollution.

Determination of glutathione and glutathione disulfide in human whole blood using HPLC with coulometric detection: A comparison with fluorescence detection

We describe a relatively simple method for the determination of glutathione (GSH) and glutathione disulfide (GSSG) in human whole blood. We have used an HPLC with coulometric electrochemical detection for the simultaneous measurement of GSH and GSSG. Diluted and filtered trichloroacetic acid extracts were injected directly into the HPLC system and were eluted isocratically on a Polaris 5u C18-A, 250 × 4.6 mm analytical column. Glutathione in samples extracted with trichloroacetic acid and diluted with 1.0 mMhydrochloric acid was stable at 4 °C for at least 8 h. The analytical performance of this method is satisfactory: the intra-assay and inter-assay coefficients of variation were below 10%. Quantitative recoveries from spiked whole blood samples were at intervals 91.6–97.6% for GSH and 85.0–104.4% for GSSG. The linear range is 5.0–2000.0 μmol/l, with a detection limit of 2.1 μmol/l (signal-to-noise ratio = 3) for GSH and 2.0–250.0 μmol/l, with a detection limit of 0.9 μmol/l for GSSG.

Simultaneous determination of oxidized and reduced glutathione in eel's (Monopterus albus) plasma by transient pseudoisotachophoresis coupled with capillary zone electrophoresis

Both the reduced form of glutathione (GSH) and the oxidized form of glutathione (GSSG) in eel's ( Monopterus albus) plasma were for the first time determined by transient pseudoisotachophoresis coupled with capillary zone electrophoresis. The method of transient pseudoisotachophoresis coupled with capillary zone electrophoresis has been thoroughly optimized and adequately evaluated for the simultaneous determination of GSH and GSSG in eel's plasma. The detection limits (S/N = 3) of the method developed were 0.2 and 0.05 micromol/L for GSH and GSSG, respectively. The linearity of the calibration curves was valid in the range of 0-10 micromol/L GSH and 0-0.70 micromol/L GSSG. The method was simple, fast, and reproducible. It was found that the respective concentrations of GSH and GSSG were in the range of 9.1-14.5 and 0.31-0.58 micromol/L in the adult eel's plasma, and 10.8-17.9 and 0.49 - 0.68 micromol/L in the juvenile eel's plasma of the three populations determined. Each blood sample was a composite of five eels. For each of the three populations, the concentrations of GSH and GSSG in the adult eel's plasma were lower than those in the juvenile eel's plasma, and the concentrations of GSH and GSSG in the plasma of population 1 (deep yellow finless eels) were higher than those in populations 2 (light yellow finless eels) and 3 (green finless eels) for either the adult or the juvenile eels.