Investigation of the effects of oxidative stress and inflammation on the pathway of tryprophan/kynurenine in obsessive compulsive disorder

Obsessive Compulsive Disorder (OCD) is a psychiatric disorder consisting of obsessions and compulsions.Causes have not been clarified yet but recent studies have shown that disruption of the Tryptophan/Kynurenine pathway may play an important role in the formation of neuropsychiatric diseases. In order to investigate this hypothesis in our study, serum and DNAs of 150 samples, including 100 OCD patients and 50 controls, were used. There were studied Glutathione Peroxidase (GSH-Px) and IDO activity and IFN gamma, Thiobarbituric acid reactive substances,Tryptophan,Kynurenine levels in the serum by ELISA method. Arylhydrocarbon Receptor (AhR) rs10249788 and cytochrome p450 family CYP1A1 rs4646903 polymorphisms, which interact directly with the kynurenine pathway from DNA samples, were analyzed by Polymerase Chain Reaction (PCR) followed by Restriction Fragment Length Polymorphism (RFLP) method. All studies were evaluated with the SPSS V21 analysis program and p<0.05 was considered statistically significant. According to the results found, no significant difference was found between patients and controls in terms of CYP1A1 rs4646903 and AhR rs10249788 polymorphisms, while Tryptophan and Interferon Gamma parameters were found to be significantly higher in controls (p<0.001, for both), and TBARS and IDO levels were found to be significantly higher in patients (p<0.001, for both). There was no significant difference between our groups in terms of GSH-Px levels. As a result of our research, it has been shown that there may be a relationship between IFN gamma, which is effective on the Tryptophan/Kynurenine pathway, and oxidative stress levels, and that this may play a role in the pathogenesis of the OCD. Our study is important because it is the first study to investigate this relationship with polymorphisms.