Compartment-specific oxidative stress signatures in oral leukoplakia: a systematic review of local and systemic biomarkers

Abstract

Oral leukoplakia (OLK) is one of the most common potentially malignant disorders of the oral mucosa. Oxidative stress is increasingly recognized as a key factor in its pathogenesis and malignant transformation, but the consistency of biomarker alterations across biological compartments remains unclear. The available evidence supports a consistent redox imbalance in OLK characterized by increased oxidative damage and impaired systemic antioxidant defenses. Salivary and serum biomarkers, particularly MDA and 8-OHdG, show promise as non-invasive indicators of oxidative stress and disease progression. However, methodological heterogeneity and small sample sizes limit clinical translation. Standardized protocols and longitudinal studies are needed to validate these biomarkers.