Investigation of proline, prolidase, proline dehidrogenase, reactive oxygen species levels in schizophrenia

Aim: The aim of our study was to evaluate serum prolidase, proline, PRODH, ROS levels in schizophrenia patients who were admitted to our outpatient psychiatry clinic and to investigate whether there was a difference between the patient group and healthy control group. Materials and Methods: The sample of the study consisted of schizophrenia patients admitted to Dicle University Psychiatry Polyclinic since 01.10.2018 and followed up in the clinic and healthy control group. The two groups were evaluated by an experienced psychiatrist in terms of age, gender, education level and smoking status. People between 18-65 years were included in the study and two groups were formed. Group 1: 85 patients diagnosed with schizophrenia according to the Fifth Edition (DSM-5) of the Diagnostic and Statistical Manual of Mental Disorders. Group 2: Consisting of 74 healthy volunteers without any psychiatric diagnosis. After the participants signed an informed consent form, sociodemographic data form was filled in to the patient and control group. Positive and Negative Syndrome Scale (PANSS), Clinical Global Follow-up Scale (CGI), Sheehan Disability Scale, Calgary Schizophrenia Depression Scale, and Hamilton Anxiety Scale were applied to the patient group. SPSS 24.0 statistical package program was used for data analysis. Findings: In our study, we found that serum proline, prolidase, PRODH and ROS levels were significantly lower than the control group (p=001 z= -3,394; p<0.001 z= -4,214; p<0.001 z= -4,372; p=0,005 z=-2,804 ). We found a high positive correlation between proline, prolidase, PRODH and ROS in both patient and control groups (p <0.001). No statistically significant difference was found between the groups in terms of gender, marital status, smoking, age, education level, BMI (p> 0.05). In our study, no significant correlation was found between the biochemical parameters of the patients and PANSS-T, PANSS-P, PANSS-N, PANSS-GP, HAM-A, CDO, STI, and QAS-S scale scores (p> 0.05). Conclusions: In our study, serum prolidase levels were significantly lower in the patient group and a significant positive correlation between prolidase levels and proline - PRODH - ROS showed a dysregulation of prolidase enzyme levels in schizophrenia patients. However, this is important to show that dysregulation also affects proline, PRODH and ROS levels downstream. Key words: Schizophrenia, prolidase, proline, proline dehydrogenase, reactive oxygen species