8-Hydroxy-2-Deoxyguanosine ,Total Antioxidant Capacity in Oral Premalignant and Malignant Lesions
Condition: Premalignant Lesion
MeSH terms: Precancerous Conditions
Study type: Observational

Summary: 
      Objectives: Investigating the level of salivary 8-hydroxy-2-deoxyguanosine (8-OHdG) and total
      antioxidant capacity (TAC) in oral premalignant and malignant lesions in order to determine
      their diagnostic value for the malignant patients. Design: 120 subjects diagnosed with oral
      leukoplakia, oral lichen planus (OLP) and oral squamous cell carcinoma (OSCC) along with
      healthy control subjects were included. Salivary samples from all participants were
      collected. 8-OHdG was measured by ELISA technique and the TAC level was assessed by a
      photometric test system.
    

Detailed description: 
      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.
    

Observational model: Other
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        The included subjects were all assessed medically according to the modified Cornell Medical
        index (Kerr & Millard, 1965).
      
Keywords: Squamous cell carcinoma; 8-hydroxy-2- deoxyguanosine; Antioxidant