The activity of markers of oxidative and nitrosative stresses in blood plasma of Parkinson’s disease patients at the early stages

Abstract

The aim of the study is to investigate activity of markers of oxidative and nitrosative stresses in blood plasma of patients in the I–II stages of Parkinson’s disease (PD) and to determine correlations between their concentrations and severity of non-motor PD symptoms. Materials and methods. 67 patients at I–II PD stages and 20 healthy controls took part in the research. Cognitive functions were examined due to the Montreal Cognitive Assessment test – MoCA test. For the severity of psycho-emotional disorders evaluation the following scales and questionnaires were used: Night Sleep Assessment Questionnaire by A. M. Vein, Zung test for anxiety, apathy Starkstein scale, Boston stress-resistance test, Beck Depression Inventory (BDI-II). We performed ELISA test for determination of glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities and 3-nitrotyrosine (3-NT) level in blood plasma of participants (Elabscience® kit). Results. The middle age of PD patients and healthy controls was 64.35 ± 1.22 and 66.40 ± 0.70 years, respectively. GPx activity in plasma of patients at І–ІІ PD stages was significantly lower than in healthy controls (P < 0.001) and was higher at the I stage compared to the II PD stage (P = 0.003). Also GPx activity in PD patients with normal cognition was higher than in PD patients with cognitive impairment (P = 0.042). The GST activity in plasma of PD patients with anxiety was significantly lower (P = 0.002) compared to those without anxiety, and 3-NT blood plasma level in PD patients with moderate anxiety was higher than in those without one (P = 0.029). Conclusions. The activity of antioxidant GPx was significantly lower in PD patients at early stages compared to healthy controls, and in PD patients in the II stage of the disease compared to the I stage, and it was significantly lower in PD patients with cognitive impairment. PD patients with moderate anxiety had lower 3-NT levels and GST activity in blood plasma.