The dynamics of nitric oxide metabolism in oral fluid in patients with oral lichen planus and chronic recurrent aphthous stomatitis

The dynamics of nitric oxide metabolism in oral fluid, specifically nitrite ions, the combined level of nitrites and nitrates, peroxynitrite, and the L-arginine/arginase system, were studied in patients with oral lichen planus (OLP) and chronic recurrent aphthous stomatitis (CRAS). A total of 40 patients with OLP and 40 with CRAS participated in the study, along with a control group of 20 healthy individuals. The study assessed the concentration of nitrite ions, the combined level of nitrites and nitrates, and peroxynitrite using spectrophotometric methods. Additionally, the activity of arginase and the concentration of L-arginine in oral fluid were determined. Results indicated that patients with OLP and CRAS exhibited significantly higher levels of nitrite ions, nitrites and nitrates combined, and peroxynitrite compared to the control group (p < 0.05). Moreover, L-arginine levels were elevated, while arginase activity was reduced in both patient groups. These findings suggest the involvement of nitric oxide metabolism disturbances in the pathogenesis of OLP and CRAS, with an imbalance in the L-arginine/arginase system contributing to disease progression. The study highlights the potential of targeting nitric oxide metabolism as a therapeutic approach in managing these oral mucosal diseases.