The Relationship between the Concentration of Salivary Tyrosine and Antioxidants in Patients with Oral Lichen Planus

Abstract

The diagnosis of oral lichen planus (OLP) is based on clinical examination and histopathological criteria. Noninvasive diagnostics of saliva may be considered as a confirmation of OLP diagnosis and a potential alternative to an invasive method. The objective of the present study was to evaluate the relationship between the level of tyrosine (Tyr) as well as antioxidants like uric acid (UA) and glutathione peroxidase (GPx) activity in the saliva of patients with OLP in comparison with the control group (healthy subjects without any oral changes). A total of 40 patients with OLP and 40 healthy volunteers were selected for the study based on the modified WHO diagnostic (clinical and histopathological) criteria. High-performance liquid chromatography (HPLC) was performed for Tyr concentration, while GPx activity and uric acid levels were determined by a colorimetric method. The concentrations of Tyr, UA, and GPx activity were statistically lowered in OLP patients compared to the control group. All examined parameters correlated strongly and positively with each other. Mean values of salivary UA concentrations differed between the groups of OLP patients (reticular and erosive forms) and controls (206.66 vs. 196.54 vs. 218.49 μmol/L, respectively, p = 0.001). A similar trend was demonstrated in salivary Tyr concentration which differed statistically between the study and control groups (0.08 vs. 0.07 vs. 0.13 μmol/L, respectively, p = 0.001). Determining of a relationship between the concentrations of Tyr, UA, and GPx activity may be useful in the prognosis of OLP. The HPLC method may be employed, as an additional noninvasive diagnostic procedure to screen OLP patients, during the routine diagnostics of salivary biochemical parameters such as aromatic amino acids.

Enhanced Salivary and General Oxidative Stress in Hashimoto’s Thyroiditis Women in Euthyreosis

“…Forty percent of the total salivary antioxidant barrier is provided by bloodborne uric acid (UA) [ 5 ]. Failure of these antioxidant systems may result in the development of oral cavity diseases, including periodontitis [ 9 , 10 ], precancerous lesions [ 11 ] and cancers [ 12 ]. Previous studies showed the alteration in the salivary antioxidants barrier and the contribution of OS in the development and progression of salivary gland dysfunction in the course of other autoimmune diseases: psoriasis vulgaris, systemic sclerosis, rheumatoid arthritis, diabetes type 1, multiple sclerosis, Sjögren’s syndrome and systemic lupus erythematosus [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ].…”

Systematic Review and Meta‐Analysis of Oxidative Stress and Antioxidant Markers in Oral Lichen Planus

“…(1) Glutathione Peroxidase (GPx) . In saliva, three studies all reported significantly lower GPx in OLP cases, while there was no significant association of GPx with OLP across the meta-analyses [ 29 , 35 , 42 ]. In addition, GPx in serum [ 29 ] (30 patients), thiol in serum [ 15 ] (22 patients), and GSH in saliva [ 32 ] (62 patients) were determined in the single study, and decreased levels were found.…”

“…UA in plasma/serum was investigated in three studies and found to be markedly decreased in OLP compared to controls (effect size -1.19, 95% CI -1.83, -0.54), with statistically significant heterogeneity ( P = 0.008, I 2 = 80%) [ 29 , 43 , 44 ]. Four studies reported lower salivary UA in OLP cases [ 29 , 42 , 44 , 45 ], while one single study did not report any statistically significant difference between OLP and controls [ 35 ]. The meta-analysis for UA assessed in saliva was -2.65 (95% CI -4.20, -1.09), with statistically significant heterogeneity ( P < 0.00001, I 2 = 97%).…”

“…In addition, GPx in serum [29] (30 patients), thiol in serum [15] (22 patients), and GSH in saliva [32] (62 patients) were determined in the single study, and decreased levels were found. [29,42,44,45], while one single study did not report any statistically significant difference between OLP and controls [35]. The meta-analysis for UA assessed in saliva was -2.65 (95% CI -4.20, -1.09), with statistically significant heterogeneity (P < 0:00001, I 2 = 97%).…”

“…Some studies focused on patients diagnosed with erosive OLP, while others did not divide OLP into different forms. The lower concentration of antioxidant defense markers and higher levels of oxidative stress markers were found in the erosive form as compared to other forms of OLP [ 32 , 42 ]. The more serious condition of oxidative stress in patients with erosive OLP seemed to reflect more intense inflammation and potential capacity for malignant transformation.…”