Exposure to air pollution and oxidative stress markers in patients with potentially malignant oral disorders.

The etiopathogenesis of potentially malignant oral disorders (PMOD) has not been fully understood yet. Recent results suggest that oxidative stress may be involved in the etiology of PMOD. Production of oxidants seems to be the major biological effect responsible for tissue injury and inflammatory response to air pollution. The aim of this study was to compare the oxidative stress markers and antioxidant potential in saliva of PMOD subjects and healthy controls in periods of high and low air pollution. Among enrolled 40 participants, there were 20 PMOD patients and 20 healthy volunteers. The exposure to air pollution was assessed by exhaled CO (eCO). Four oxidative status parameters: 8-hydroxy-2'-deoxyguanosine (8-OHdG), malondialdehyde (MDA), reduced glutathione (GSH) and total antioxidant capacity (TAC) were measured in saliva. Measurements were carried out in June (low air pollution) and November (increased air pollution). In both groups, significantly higher concentrations of 8-OHdG (P < 0.001 for PMOD patients and P = 0.001 for healthy controls), MDA (P = 0.002 and P = 0.012 respectively) and eCO (P < 0.001 and P < 0.001 respectively) were observed in periods of high air pollution. The concentration of TAC did not change between visits. The concentration of salivary GSH (P < 0.001 and P < 0.001 for both groups) decreased when compared between consecutive visits. We conclude that exhaled carbon monoxide (reflecting exposure to air pollution) correlated with the oxidative stress markers in patients with PMOD and healthy controls.

Salivary oxidative status in patients with oral lichen planus.

Reactive oxygen species (ROS) are involved in the pathogenesis of many inflammatory diseases, including oral lichen planus. Therefore, determining the salivary markers of oxidative stress is an excellent alternative approach to diagnosing oral cavity diseases. The objective of our study was to provide preliminary validation and determination of the salivary markers of oxidative stress in both patients with reticular and erosive forms of oral lichen planus as well as in healthy individuals without any oral lesions. In total, 62 patients with oral lichen planus (OLP) were enrolled in the study, including 31 with the reticular form of lichen planus (44.63 ± 11.05 years) and 31 with erosive forms (40.43 ± 10.05 years), who had never been treated for their disease. The control group comprised 30 individuals without any oral lesions (42.12 ± 12.22 years). We determined the saliva levels in glutathione (GSH), total antioxidant capacity (TAC), and thiobarbituric acid reactive substances (TBARS). The mean saliva levels of GSH and TAC were significantly lower (P < 0.01) in OLP patients compared to the control group. The mean levels of salivary TBARS were higher in both OLP groups (reticular and erosive) compared to the control group (P = 0.01). The lower saliva levels of GSH and TAC in patients with OLP indicate that free radicals and the resulting oxidative damage may play an important role in the pathogenesis of OLP lesions. In conclusion, monitoring the oxidant-antioxidant status of saliva may serve as an efficient and less intrusive marker for determining stages of disease development in patients with OLP.