Capillary Blood GSH Level Monitoring, Using an Electrochemical Method Adapted for Micro Volumes.

Zaneta Buchtova,Zdenek Zitka,Jan Skoda,Zuzana Lackova,Jiri Kudr,Ondrej Zitka

doi:10.3390/molecules23102504

Abstract

Glutathione (γ-glutamyl-cysteinyl-glycine; also known as GSH) is an endogenous antioxidant that plays a crucial role in cell defense mechanisms against oxidative stress. It is thus not surprising that this molecule can serve as a biomarker for oxidative stress monitoring. As capillary blood is a highly accessible target for biomarking, it is a valuable bodily fluid for diagnosing human GSH levels. This study focused on the optimization of GSH measurements from micro volumes of capillary blood prior to using electrochemical detection. The optimization of experimental parameters, including the sample volume and its stability, was performed and evaluated. Moreover, we tested the optimized method as part of a short-term study. The study consisted of examining 10 subjects within 96 h of their consumption of high amounts of antioxidants, attained from a daily dose of 2 g/150 mL of green tea. The subjects’ capillary blood (5 μL) was taken at 0 h, 48 h, and 96 h for subsequent analysis. The short-term supplementation of diet with green tea showed an increase of GSH pool by approximately 38% (between 0 and 48 h) within all subjects.

Highlights

Antioxidants are important molecules that prevent negative effects of free radicals, produced in vivo by molecular oxygen metabolism
Suitability of the method was proved by performing a simple experiment, showing the short-term effects of green tea supplementation on GSH levels of 10 volunteers
A fast increase of GSH levels in the capillary blood of volunteers, due to consumption of green tea, was observed. This was in a strong agreement with an observed increase of total thiol concentration in the samples

Summary

Introduction

Antioxidants are important molecules that prevent negative effects of free radicals, produced in vivo by molecular oxygen metabolism. Glutathione (L-γ-glutamyl-L-cysteinyl-glycine; known as GSH) is one of the most important intracellular, non-enzymatic antioxidants [8,9], and is valuable as a pool-making, cofactor substance for the neutralization of reactive oxygen/nitrogen species (ROS, NOS). It plays an important role in nutrient metabolism, cell regulation (including gene expression), DNA and protein synthesis, signal transduction, proliferation and apoptosis, production of cytokines, and immune response [5,10,11,12,13,14]

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Conclusion