A novel automated direct measurement method for total antioxidant capacity using a new generation, more stable ABTS radical cation

EREL Ö.

Clinical Biochemistry, vol.37, no.4, pp.277-285, 2004 (SCI-Expanded, Scopus)

  • Publication Type: Article / Article
  • Volume: 37 Issue: 4
  • Publication Date: 2004
  • Doi Number: 10.1016/j.clinbiochem.2003.11.015
  • Journal Name: Clinical Biochemistry
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.277-285
  • Keywords: ABTS, ABTS radical cation, Antioxidant, Antioxidant capacity, Automated measurement, FRAP, Free radicals, Oxidative stress, Total antioxidant capacity
  • Ankara Yıldırım Beyazıt University Affiliated: Yes

Abstract

Objectives: To develop a novel colorimetric and automated direct measurement method for total antioxidant capacity (TAC). Design and Methods: A new generation, more stable, colored 2,2′-azinobis-(3- ethylbenzothiazoline-6-sulfonic acid radical cation (ABTS*+) was employed. The ABTS*+ is decolorized by antioxidants according to their concentrations and antioxidant capacities. This change in color is measured as a change in absorbance at 660 nm. This process is applied to an automated analyzer and the assay is calibrated with Trolox. Results: The novel assay is linear up to 6 mmol Trolox equivalent/l, its precision values are lower than 3%, and there is no interference from hemoglobin, bilirubin, EDTA, or citrate. The method developed is significantly correlated with the Randox- total antioxidant status (TAS) assay (r = 0.897, P < 0.0001; n = 91) and with the ferric reducing ability of plasma (FRAP) assay (r = 0.863, P < 0.0001; n = 110). Serum TAC level was lower in patients with major depression (1.69 ± 0.11 mmol Trolox equivalent/l) than in healthy subjects (1.75 ± 0.08 mmol Trolox equivalent/l, P = 0.041). Conclusions: This easy, stable, reliable, sensitive, inexpensive, and fully automated method described can be used to measure total antioxidant capacity. © 2004 The Canadian Society of Chemical Chemists. All rights reserved.