Total Salivary Antioxidant and Serum Antioxidant Levels in Recurrent Aphthous Stomatitis: A Case-Control Study

Recurrent Aphthous Stomatitis (RAS) is an inflammatory lesion of the oral mucous lining, accounting for 5 to 25% of the chronic oral lesions. Studies have suggested that RAS patients have increased oxidative stress (OS) and impaired antioxidant capacity, and non-invasive screening using saliva assessment of oxidative stress and antioxidant capacity may be beneficial in RAS.

This study determined total salivary antioxidant concentration and compared it to the total serum antioxidant levels in patients with RAS and controls.

This was a case-control study of subjects with RAS and without RAS. Unstimulated mid-morning saliva was collected using the spitting method, and venous blood was collected into a plastic vacutainer. Saliva and blood samples were assayed for total oxidative stress (TOS), total antioxidant capacity (TAC), ferric reducing antioxidant power (FRAP) and glutathione.

A total of 46 subjects, 23 with RAS and 23 healthy controls, participated in the study. Twenty-five (54.35%) were males, and 21(45.65) were females aged 17 to 73 years. We identified an increase in salivary and serum TOS (10.06 ± 7.49, 8.26 ± 2.18/ 15.00 ± 8.92, 9.36 ± 3.55µmol/L) and OSI while the TAC (16.85 ± 1.97, 17.07 ± 2.36/17.07 ± 2.36, 2.97 ± 0.29mM/L) and significantly GSH (0.02 ± 0.02, 0.10 ± 0.02/0.10 ± 0.02/0.19 ± 0.11 µmol/ml) were decreased in serum and saliva of the RAS group compared to controls respectively. In addition, there were positive correlations between salivary and serum levels of FRAP r=0.588, p= 0.003 and glutathione r=0.703, p<0.001 in RAS subjects and controls.

Oxidative stress is associated with RAS, and saliva can be used as a biological marker for glutathione and FRAP.