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Turkish Journal of Biology

Abstract

Background/aim: Uric acid is a major contributor to the total antioxidant capacity of human plasma. However, this endogenous substance’s antioxidant and prooxidant properties have not yet been reported.

Conclusion: In this study, the comet assay was employed in vitro to determine the effect of uric acid on DNA damage in human lymphocytes and leukocytic DNA damage in hyperuricemia patients with and without renal failure.

Results: DNA damage in lymphocytes occurred at uric acid concentrations of ≥600 μM. Adding catalase to the uric acid solution diminished the damaging effect, indicating that hydrogen peroxide mediated the prooxidant activity. Moreover, adding Fe2+ did not enhance the DNA damage, suggesting that the urate’s prooxidant activity is independent of the Fenton reaction. The unstable nature of uric acid at nearly neutral and acidic pH levels resulted in autooxidation and the generation of hydrogen peroxide. Maintaining the stability of uric acid in vivo may lead to the consumption of antioxidants in the body and affect the antioxidant status. Hyperuricemia patients with and without renal failure had higher levels of leukocytic DNA damage compared to healthy individuals. However, there was no significant difference in leukocytic DNA damage between hyperuricemia patients with and without renal failure, which showed that the damaging effect was not due to renal failure. A correlation study suggested that serum uric acid level had a stronger correlation with DNA damage than the severity of renal failure as indicated by serum creatinine or urea.

Conclusion: Uric acid demonstrated prooxidant activity in both in vitro and in vivo studies, which was mediated by the production of hydrogen peroxide and independent of both the Fenton reaction and renal failure.

Author ORCID Identifier

YIM TONG SAVIO SZETO: 0000-0002-1711-8510

VINCY SZE WING LI: 0000-0000-0000-0001

YUEN LAM PON: 0000-0002-1129-5997

DOI

10.55730/1300-0152.2735

Keywords

Antioxidant, comet assay, DNA, prooxidant, urate

First Page

175

Last Page

184

Publisher

Scientific and Technological Research Council of Türkiye (TUBITAK)

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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