Nitrosative stress parameters and the level of oxidized DNA bases in patients with multiple sclerosis.

Multiple sclerosis (MS) is a neurodegenerative disease with various factors affecting its etiology. Overproduction of nitric oxide and subsequent lesions of biopolymers are some of the possible causes of the disease. This study aimed to measure the most relevant nitrosative and oxidative stress biomarkers and the level of modified DNA bases in patients with MS. Each parameter was assayed in 25 patients with MS and 25 healthy controls. This study involved detecting blood plasma and serum nitric oxide metabolites by chemiluminescence detector Sievers NOA-280i, malondialdehyde (MDA) measurements with thiobarbituric acid reactive substance (TBARS) assay, detection of oxidized purines and pyrimidines with the enzyme-modified comet assay. Statistical analysis of the results was performed by one-way analysis of variance (ANOVA) and unpaired t test for the comparison of less than three data sets. DNA single-strand breaks, levels of modified purines and pyrimidines, as well as nitrite and nitrate levels in plasma and serum samples, were significantly higher in patients with MS than in healthy controls. On the contrary, MDA levels appeared to be lower in patients with MS.