Local and systemic oxidative stress in oral leukoplakia: A systematic review.

Abstract

Oral leukoplakia (OLK) is one of the most common oral potentially malignant disorders and carries a risk of transformation into oral squamous cell carcinoma (OSCC). While its exact etiology remains unclear, oxidative stress has been proposed as a key factor in its pathogenesis. This systematic review aimed to evaluate the presence of local and systemic oxidative stress in patients with OLK through the analysis of specific oxidative and antioxidant biomarkers. A comprehensive search was conducted across PubMed, Web of Science, and Scopus databases, including studies published between 2000 and 2024. 15 studies met the inclusion criteria, involving a total of 1,315 patients and analyzing samples from serum, saliva, and oral tissue. The results demonstrated a consistent increase in oxidative markers such as MDA and 8-OHdG in OLK patients compared to healthy controls. In parallel, significant decreases in antioxidants like GSH, GPx, SOD, CAT, and vitamins C and E were observed. Several studies also reported a correlation between the degree of epithelial dysplasia and oxidative damage, suggesting a potential link between oxidative imbalance and malignant transformation. These findings support the hypothesis that oxidative stress plays a significant role in the development and progression of OLK. Furthermore, the identification of reliable oxidative biomarkers could contribute to improved early diagnosis and clinical management. Future research is needed to validate these markers and explore antioxidant-based therapeutic strategies.