Abstract
BACKGROUND AND OBJECTIVES: Among the various biofluids, 8-isoprostane is a relatively underexplored yet stable oxidative stress biomarker that can be detected in measurable quantities. It is a unique by-product of arachidonic acid lipid peroxidation, and in recent years, its expression has been investigated in various diseases, particularly in malignancies. Our study was performed to evaluate the level of 8-isoprostane and compare its expression in plasma and saliva samples of oral leukoplakia (OL), oral submucous fibrosis (OSMF) patients and healthy controls (HC). METHODOLOGY: Plasma and saliva samples were collected from clinically and histopathologically confirmed cases of OL, OSMF and HC, with 12 participants in each group. The 8-isoprostane levels in all samples were analysed using the enzyme-linked immunosorbent assay (ELISA) technique. RESULTS: The expression of 8-isoprostane level was statistically significant (P < 0.05) in both plasma and saliva, denoting a steady elevation of 8-isoprostane level in oral potentially malignant disorder (OPMD) (OSMF and OL), when compared to HC. However, when compared to saliva, plasma 8-isoprostane levels were higher in the OL group, whereas the reverse trend was observed in the OSMF group, where salivary levels were higher. CONCLUSION: The study reveals a significant plasma and salivary 8-isoprostane level, where the concentration was higher in OPMD groups implying that saliva could be used as the diagnostic sample of choice for evaluating this oxidative stress marker.