EVALUATION OF SALIVA AND SERUM HEME OXYGENASE, ARYLESTERASE AND NUCLEAR FACTOR ERYTHROID 2-RELATED FACTOR 2 LEVELS IN PATIENTS WITH STAGE III PERIODONTITIS

serum and saliva TAS (mmol Trolox Eq/L) levels

TAS concentrations were evaluated utilizing an innovative automated colorimetric assay, originally developed by Erel. The outcomes were reported as millimoles of Trolox equivalent per liter (mmol Trolox Eq/L). Total antioxidant levels are significantly lower in periodontitis patients compared to healthy individuals, suggesting increased oxidative stress associated with periodontal inflammation.

Time frame: 6 months

serum and saliva TOS (µmol H₂O₂ Eq/L) levels

TOS concentrations were determined through a distinct automated colorimetric technique, also described by Erel. Results were expressed as micromoles of hydrogen peroxide equivalent per liter (µmol H₂O₂ Eq/L). Compared to healthy controls, periodontitis patients show higher total oxidant levels, which may contribute to tissue destruction and disease progression.

Time frame: 6 months

serum and saliva OSI levels

TAS values (initially in mmol Trolox Eq/L) were converted to µmol Trolox Eq/L. OSI was then computed using the following formula: OSI = \[(TOS, µmol/L) / (TAS, µmol Trolox Eq/L)\] × 100. The oxidative stress index is significantly higher in periodontitis patients compared to healthy individuals, reflecting an imbalance between oxidants and antioxidants.

Time frame: 6 months

serum and saliva ARE (U/L) levels

Arylesterase activity was assessed using commercially available assay kits (Rel Assay Diagnostics, Turkey). For the measurement of arylesterase activity, phenylacetate was used as the substrate. The enzymatic activity was calculated based on the molar extinction coefficient of the phenol formed (1,310 M-¹cm-¹). One unit of arylesterase activity was defined as the amount of enzyme required to hydrolyze 1 µmol of phenol per minute under the assay conditions and was also expressed as U/L. Arylesterase activity is significantly decreased in periodontitis patients compared to healthy controls, suggesting impaired antioxidant enzyme function.

Time frame: 6 months

serum and saliva NRF-2 (ng/ml) levels

The level of NRF-2 was quantified using an enzyme-linked immunosorbent assay (ELISA) kit (BT lab.). In this assay, wells were pre-coated with human NRF-2-specific antibodies. Samples containing NRF2 were added to the wells, allowing target binding. Subsequently, a biotin-conjugated anti-NRF-2 antibody was applied, followed by streptavidin-horseradish peroxidase (HRP) conjugate. After washing to remove unbound components, a substrate solution was added, producing a colorimetric reaction proportional to the amount of NRF-2 present. The reaction was terminated by adding an acidic stop solution, and absorbance was measured at 450 nm. It is suggested that the reduced expression of NRF-2 in periodontitis patients, relative to healthy controls, contributes to increased oxidative stress and tissue damage.

Time frame: 6 months

serum and saliva HO-1(ng/ml) levels

The concentration of HO-1 was measured using an ELISA kit (BT Lab.) Wells were pre-coated with human HO-1-specific antibodies. Following the addition of samples, human HO-1 proteins bound to the immobilized antibodies. A biotinylated anti-HO-1 antibody and subsequently streptavidin-HRP conjugate were introduced. After removal of unbound components via washing, a substrate solution was added to initiate color development, which was proportional to the HO-1 concentration. The reaction was stopped using an acidic solution, and absorbance was recorded at 450 nm. Compared to healthy subjects, HO-1 is considered to be less expressed in periodontitis patients, potentially compromising antioxidant and anti-inflammatory defenses

Time frame: 6 months