RESUMO
BACKGROUND: The aim of this study was to investigate enzymatic and non-enzymatic antioxidant systems and levels of biomarker levels of oxidative damage in the saliva of patients with Down's syndrome (DS). METHODS: Saliva samples were collected from 30 patients with DS and control group (age: 14-24 years). Subsequently, the concentrations of superoxide dismutase, concentration of malondialdehyde, carbonylated proteins, uric acid, vitamin C and total protein, peroxidase activity and total antioxidant capacity were analyzed. RESULTS: Patients with DS presented significantly higher concentrations of superoxide dismutase, higher levels of malondialdehyde and salivary total protein content than controls (p<0.05). Conversely, no difference in carbonylated proteins or antioxidants (uric acid, vitamin C, peroxidase, and total antioxidant capacity) was observed between DS patients and controls (p>0.05). CONCLUSION: Patients with DS are more vulnerable to oxidative stress in saliva as indicated by the significant increase in malondialdehyde and superoxide dismutase concentrations found in this study.
