Markers of oxidative stress in plasma and saliva in patients with multiple sclerosis

Backround: Oxidative stress plays a role in multiple sclerosis. Saliva can be potentially used to study the disease progression or treatment, because of its non-invasiveness and easy collection. But studies on saliva and multiple sclerosis are missing. The aim of this study was to compare the concentrations of salivary oxidative stress markers in patients and healthy controls.

Objective: Whole saliva and blood samples were collected from 29 patients and 29 healthy controls. Samples were collected during relapse, after corticosteroid therapy, and after three months. Markers of oxidative, carbonyl stress and antioxidant status were measured.

Results: In plasma, thiobarbituric acid reacting substances, advanced oxidation protein products and fructosamine were significantly higher in patients compared to controls (by 271%, 46% and 24%, respectively; p<0.01). Total antioxidant capacity in plasma was lower by 20% (p<0.01) in patients versus controls. In saliva, higher levels of thiobarbituric acid reacting substances and advanced glycation end-products were observed in patients when compared to controls (by 51% and 49% respectively; p<0.01). Ferric reducing ability was reduced by 38% (p<0.05) in patients with multiple sclerosis.

Conclusion: According to our knowledge, this is the first report showing higher markers of oxidative stress and lower antioxidant status in patients with multiple sclerosis in saliva.