Salivary thioredoxin-1 as a non-invasive redox biomarker in oral diseases

Abstract

Thioredoxin-1 (Trx-1) is a key redox-regulating protein involved in antioxidant defense, inflammation, immune responses, and cell survival. Dysregulation of redox balance is increasingly being recognized as a central mechanism in the pathogenesis of a wide spectrum of oral diseases, ranging from inflammatory conditions to oral potentially malignant disorders and oral squamous cell carcinoma. Saliva, owing to its non-invasive, accessible, and disease-reflective nature, has emerged as a promising diagnostic medium for redox and inflammatory biomarkers. Limited but emerging evidence suggests that salivary Trx-1 levels may be altered in oral diseases associated with oxidative stress and chronic inflammation, reflecting underlying molecular and cellular changes within the oral microenvironment. From a clinical perspective, assessment of salivary Trx-1 may assist in early disease detection, chairside risk stratification, and longitudinal monitoring of disease activity and treatment response. Elevated salivary Trx-1 expression has been associated with disease presence, severity, and malignant transformation risk, highlighting its potential diagnostic and prognostic utility. Despite these advantages, variability in detection methods, population heterogeneity, and limited longitudinal data remain challenges to clinical translation. Overall, salivary Trx-1 represents a promising non-invasive redox biomarker with significant potential for improving early detection, risk assessment, and personalized management of oral diseases.

Keywords: Oral disease; Oxidative stress; Redox marker; Salivary biomarker; Thioredoxin-1

Core Tip: Redox imbalance is an important mechanism in the etiopathogenesis of various diseases, including periodontal diseases, oral potentially malignant disorders, and squamous cell carcinoma of the oral cavity. Thioredoxin-1 (Trx-1), which acts as a redox regulator, plays a crucial role in the body’s antioxidative protection, inflammation, apoptosis processes and tumor growth. The detection of Trx-1 in saliva may serve as a promising non-invasive method for early diagnostics and prognosis in the diseases of the oral cavity.