An investigation of glutathione-platinum(II) interactions by means of the flow injection analysis using glassy carbon electrode

Abstract

Despite very intensive research in the synthesising of new cytostatics, cisplatin is still one of the most commonly used anticancer drugs. Therefore, an investigation of interactions of cisplatin with different biologically important amino acids, peptides and proteins is very topical. In the present paper, we utilized flow injection analysis coupled with electrochemical detection to study and characterize the behaviour of various forms of glutathione (reduced glutathione - GSH, oxidized glutathione - GSSG and S- nitroso glutathione - GSNO). The optimized conditions were as follows: mobile phase consisted of acetate buffer (pH 3) with a flow rate of 1 mL min(-1). Based on results obtained we chose 850 mV as the optimal potential for detection of GSH and 1,100 mV as the optimal potential for detection of GSSG and GSNO. The detection limits of GSH, GSSG and GSNO were 100 pg mL(-1), 50 ng mL(-1) and 300 pg mL(-1), respectively. Further, the optimized technique was used for investigation of interactions between cisplatin and GSH. We were able to observe the interaction between GSH and cisplatin via decrease in the signal corresponding to glutathione. Moreover, we evaluated the formation of the complex by spectrometry. The spectrometric results obtained were in good agreement with electrochemical ones.