The aim of our work was to optimize and apply simple high-performance liquid chromatography method with ultraviolet detection (HPLC—UV) for simultaneous determination of reduced (GSH) and oxidized (GSSG) glutathione in biological matrix (specifically, the rat liver tissue was used herein), since the ratio between oxidized and reduced glutathione forms (GSSG—GSH) has been recognized as an important biological marker of oxidatively depleted GSH in oxidative stress (OS)-associated diseases and poisonings. An isocratic chromatographic separation of GSH and GSSG (2.8 min and 6.3 min, respectively) was performed with the mobile phase consisted of sodium perchlorate solution (pH adjusted to 2.8) at flow rate of 1 mL min −1, detection set at 215 nm, and column temperature of 40 °C. The method offers short run time, linearity in the range of 0.01—200 μM concentration for both compounds ( R 2 = 1), low limits of detection and quantification (GSH: 0.18 μM and 0.56 μM, GSSG: 0.52 μM and 1.58 μM, respectively), precision, accuracy (bias < 2%), and high reproducibility.
Through suitable sample handling, an overestimation of GSSG was prevented. High recovery (>99%) was achieved. The method was successfully applied for the analysis of GSH and GSSG in liver homogenates of Wistar rats intraperitoneally exposed to cadmium (Cd) (1 mg kg −1 CdCl 2/21 days). Regardless of other Cd-mediated hepatotoxicity mechanisms, herein, we have exclusively interpreted/emphasized oxidative GSH depletion.
The presented method is acceptable for a routine analysis of GSH and GSSG in biological matrix, while the calculated ratio GSSG—GSH is considered as a valuable OS marker.