Development of UPLC-MS/MS methods for quantitation of glutathione, cysteine, 14,15-epoxyeicosatrienoic acid, and 15-hydroxyeicosatetraenoic acid and application in paraquat poisoning cells

Glutathione (GSH) and cysteine are important antioxidants in maintaining the oxidation-reduction balance. 14,15-epoxyeicosatrienoic acid (14,15-EET) and 15-hydroxyeicosatetraenoic acid (15-HETE) are biological active compounds metabolized from arachidonic acid. To dynamically monitor GSH, cysteine, 14,15-EET, and 15-HETE, an ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) method was developed. The derivative GSH, cysteine, and underivatized 14,15-EET, 15-HETE were determined by electrospray ionization source with multiple reaction monitoring. The developed method was well validated and applied to monitor the extracellular concentration of GSH, cysteine, 14,15-EET, and 15-HETE in paraquat (PQ) poisoning LO2 cells. It was shown that the derivation of GSH and cysteine is complete and specific. There was a good linear relationship among GSH, cysteine, 14,15-EET, and 15-HETE. The relative standard deviations of precision and accuracy were all within 15%. After PQ poisoning, the extracellular concentrations of GSH and cysteine were increased at 72 h. 14,15-EET and 15-HETE started to increase at 24 h, earlier than GSH and cysteine. Irreversible pathological alterations appeared at 48 h. In conclusion, a fast and specific UPLC-MS/MS method for the determination of GSH, cysteine, 14,15-EET, and 15-HETE has been developed and validated. PQ induced the increase of 14,15-EET and 15-HETE earlier than that of GSH and cysteine in LO2 cells culture medium.