Estimation of Serum Malondialdehyde and Assessment of DNA Damage using Comet Assay in Patients with Oral Submucous Fibrosis

Oral submucous fibrosis is a potentially malignant disease caused by chewing of areca nut and is associated with an increased risk for malignancy. It is a chronic disorder characterized by fibrosis of the submucosa of the upper digestive tract involving the oral cavity, oropharynx and upper third of the oesophagus. One of the important hallmarks for cancer progression is DNA damage resulting from various carcinogens. One of the most frequently used biomarkers providing an indication of the overall lipid peroxidation level is the plasma concentration of malondialdehyde (MDA).
The study was conducted in the Department of Oral Medicine and Radiology. Malondialdehyde levels were estimated using spectrophotometric methods in blood sample. DNA damage was assessed using COMET assay by electrophoresis. The damaged DNA fragments will move towards the positive electrode giving rise to a comet like appearance. The extent of DNA damage is estimated by calculating the parameters of the comet-tail.
Comet assay results showed that there was a statistically significant increase in tail length, percentage of tail DNA and tail moment among SMF subjects (p < 0.05). Serum MDA levels were elevated in oral submucous fibrosis patients compared with healthy subjects. A significant positive correlation was observed between serum MDA levels and comet tail length in SMF group (r = 0.56; p < 0.05).
To conclude, patients with oral submucous fibrosis have increased DNA damage and elevated levels of serum malondialdehyde compared with healthy controls.