Imbalance of Free Radicals and Antioxidants in Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma: A Review

BACKGROUND: The dynamic interplay between reactive free radicals (FR) and antioxidants (AO) can lead to either redox homeostasis or oxidative stress. Disruption of redox balance contributes to oxidative stress, a key factor in the pathogenesis of various conditions, notably oral potentially malignant disorders (OPMDs) and oral squamous cell carcinoma (OSCC). At low to moderate levels, FRs trigger adaptive mutations that initiate carcinogenesis and support neoplastic cell survival. In contrast, high concentrations of FRs exert cytotoxic effects, a mechanism exploited in radiotherapy and chemotherapy. Antioxidants counteract FRs, mitigating cellular damage-a benefit demonstrated in several clinical trials involving OPMDs. However, their efficacy in OSCC remains contentious. METHODS AND FINDING: This review explores the multifaceted roles of FRs and AOs in OPMD and OSCC, with emphasis on their contributions to carcinogenesis and therapeutic strategies. Tracking the FR-AO ratio during treatment may offer predictive insights into malignant transformation and facilitate early OSCC detection.