Measuring the Antioxidant Capacity Induced by Reduced Thiols in Human Erythrocytes Using SW-Voltammetry

Author(s)

Mariano Vilhena, Maria Ines ; Correa-da-Silva, Marcos Vergilio ; de Arruda, Ana Carolina ; Ribeiro, Beatriz Felicio ; Zeni Beretta, Ana Laura Remedio ; Alves, Armindo Antonio

• Document type: Journal article
• Source: International Journal of Electrochemical Science; v. 11, n. 8, p. 6453-6465, AUG 2016.
• Web of Science Citations: 1

Abstract

This study examines the use of square wave voltammetry (SWV) to measure the antioxidant capacity induced by reduced thiols in human erythrocytes using a static mercury drop (working), a platinum wire (auxiliary) and the Ag/AgCl saturated electrode. The erythrocytes were isolated from fresh collected blood of 15 subjects aged between 20-30 years old. The applayed voltage ranged from -0.8 to -0.4 V. The current intensity peak (Ip) increases with the hemoglobin concentration (11.3 - 86.0 mon) of the erythrocyte mixture (line equation R=0.9), increasing additions of reduced glutathione (0-90 mu mol/L ) to 23 mon of hemoglobin. The signal decreases when increasing concentrations of diamide (a specific thiol ligant) (0 - 46 mmol/L) was added to the erythrocyte preparation (70.0 mu mol/L hemoglobin). This decreasing was fitted by a quadratic equation (R-2=0.99). The SWV method demonstrate to be more adequate to quantify the oxidative attack promoted by small concentrations of H2O2 (0-53 mon) to the erythrocyte preparation (65 mu mol/L hemoglobin), when compared to the spectrophotmoetric method that detect the diminishment of oxyhemoglobin and increase of methemoglobin and hemichrome. These results allow the use of the proposed method to quantify alterations in the antioxidant status of the human erythrocytes. (AU)

• FAPESP's process: 10/02791-7 - Standardization of voltametric methods to measure the concentration of GSH and protein cysteine residues in erytrocytes and plasma
• Grantee: Armindo Antonio Alves
• Support Opportunities: Regular Research Grants