8-Hydroxy-2-Deoxyguanosine ,Total Antioxidant Capacity in Oral Premalignant and Malignant Lesions

Detection of molecular markers in saliva is superior to their detection in serum and other body fluids due to the fact of being an easy non-invasive tool requiring no training for its collection. Consequently, the aim of our work was to investigate salivary 8-OHdG and TAC in premalignant and malignant patients compared to normal subjects and to determine their diagnostic value for the malignant patients.

Methodology:

Study population:

A total of 120 subjects were enrolled in the present study. The clinically tested and confirmed subjects included Group A: 30 patients diagnosed with oral leukoplakia Group B: 30 patients suffering from oral lichen planus Group C: 30 patients having oral squamous cell carcinoma with the tongue being the most commonly affected site Group D: 30 age and gender matched individuals having no oral mucosal lesions acting as a control group.

Comprehensive oral diagnosis was done for all participating individuals. Biopsy specimens were obtained from various lesions where a surgical double wedge incisional biopsy was carried out to a depth of about 2mm. Specimens were sent for histopathological examination to confirm the clinical diagnosis.

Salivary sample collection: Collection of whole unstimulated saliva from all participants was performed using standard techniques.Subjects refrained from eating, drinking, chewing gum etc., for at least ½ h before the evaluation.Samples were collected by asking individuals to swallow first, tilt their head forward and expectorate all saliva in a tube for 5 minutes without swallowing. After collection, all samples were immediately stored at -20ºC until assayed.

Detection of salivary 8-OHdG: Saliva was centrifuged for 5 minutes at 5000 x g. The supernatant was removed for determination of 8- hydroxy-2'-deoxyguanosine using an ELISA kit provided by BioVision, USA (Catalog # K4160-100). 8-hydroxy-2'-deoxyguanosine is an oxidized derivative of deoxyguanosine and is one of the major products of DNA oxidation.

Determination of salivary total antioxidative status/capacity (TAS/TAC) was done using ImAnOx (TAS/TAC) Kit provided by Immun Diagnostik, Germany. It is a photometric test system used for the determination of the total antioxidative status/capacity in EDTA-plasma, serum and other biological samples.

The determination of the antioxidative capacity was performed by the reaction of antioxidants in the sample with a defined amount of exogenously provided hydrogen peroxide (H2O2). The antioxidants in the sample eliminate a certain amount of the provided H2O2. The residual H2O2 was determined photometrically by an enzymatic reaction which involves the conversion of TMB to a colored product. After addition of a stop solution, the samples were measured at 450 nm in a microtiter plate reader. The quantification was performed by the delivered calibrator. The difference between applied and measured peroxide concentration in a defined time period is proportional to the reactivity of the antioxidants of the sample (antioxidative capacity). Quantification was performed with the enclosed calibrator.

Inclusion criteria

All included individuals were not under any current medication, suffering from any systemic condition or having any other oral mucosal disorder.

Exclusion criteria

• Pregnant or lactating females
• subjects having systemic disorder or taking medications;
• subjects who suffer from any other mucosal lesions.
• severe periodontal inflammation