The evaluation of Thiol/Disulfide Homeostasis and Oxidative DNA Damage in Patients with Obsessive Compulsive Disorder
Faruk Kurhan 1, 1, 1*, hamit hakan alp 2, 2, 2, mesut ışık 1, 1, 1, yavuz selim atan 1, 1, 1
1Yuzuncu Yıl University, psychiarty department, Tusba, Van, Turkey, 2Yuzuncu Yıl University,biochemistry department, Tusba, Van, Turkey
Received: November 1, 2020; Revised: December 14, 2020; Accepted: December 18, 2020; Published online: December 18, 2020.
© The Korean College of Neuropsychopharmacology. All rights reserved.

The number of studies on oxidative stress in the etiology of Obsessive Compulsive Disorder (OCD) is limited. Thiol / disulfide homeostasis is a new marker of oxidative stress. In this study, we aimed to examine Thiol / disulfide homeostasis and oxidative DNA damage in patients with OCD and compare them with healthy controls.
Thirty-five patients previously diagnosed with OCD in Van Yuzuncu Yil University Department of Psychiatry and thirty-three healthy volunteers were included in the study. The patients were diagnosed by a psychiatrist according to DSM-5 diagnostic criteria. The severity of the symptoms was measured using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). Five cc of blood samples were taken from the patient and control groups. The samples were stored at appropriate conditions until use. Leukocyte DNA was isolated and the levels of 8-hydroxy-2-deoxyguanosine (8-OHdG) and deoxyguanosine were detected to assess the oxidative DNA damage. The level of oxidative DNA damage was expressed as 8-OHdG/106dG. Total thiol / native thiol levels were measured for thiol/disulfide homeostasis. The level of disulfide was determined by subtracting the native thiol value from the total thiol value and the result was divided by two. Results were given as percentages.
The total and native thiol levels in patients with OCD were significantly lower, and the disulfide levels were significantly higher in patients with OCD than healthy control subjects. In addition, 8-OHdG, an indicator of DNA damage, was significantly lower in the control group compared to the patient group.
Increased levels of disulfide/native thiol and disulfide/total thiol in patients with OCD show that levels of oxidative stress were elevated and therefore, higher 8-OHdG levels in patients with OCD is a marker of oxidative DNA damage. In this context, it shows that thiol/disulfide homeostasis can be used as a new marker in the pathophysiology of oxidative stress in patients with OCD.
Keywords: Obsessive-Compulsive Disorder, Thiol / Disulfide balance, DNA Damage