Peroxiredoxins: Guardians Against Oxidative Stress in Chronic Periodontitis—A Systematic Review on their Role in Redox Regulation and Periodontal Pathogenesis

Background: Chronic periodontitis, an inflammatory disease associated with oxidative stress, is driven by a host immune response to bacterial infection. The condition is linked to systemic illnesses such as cardiovascular disease and diabetes, where oxidative stress plays a pivotal role in its pathogenesis. Peroxiredoxins (Prx), a family of antioxidant proteins, have been implicated in mitigating oxidative stress, yet their role in chronic periodontitis remains underexplored. This is the first systematic review to consolidate current evidence on Prx as modulators of oxidative stress in chronic periodontitis. Objectives: This systematic review aims to synthesize existing evidence on the expression and activity of Prx in chronic periodontitis, examining their potential role in modulating oxidative stress and inflammation. Methods: A systematic search was conducted in seven electronic databases and gray literature sources between March and December 2024, following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Studies involving oxidative stress markers, Prx, and chronic periodontitis in individuals aged 18 and older were included. Data on study design, sample characteristics, oxidative stress measurements, and Prx expression were extracted and narratively synthesized. The risk of bias was assessed using the Joanna Briggs Institute (JBI) critical appraisal tools. Results: Four studies met the inclusion criteria, comprising two observational studies, one case-control study, and one in-vitro experimental study. Prx expression was evaluated using immunohistochemistry, quantitative real-time Polymerase Chain Reaction (PCR), and multiplex immunoassays. Prx1 expression was significantly elevated in chronic periodontitis, approximately a 2.0–2.5-fold increase compared to healthy controls ( p < .05), while Prx2 levels showed a 1.5–2.0-fold upregulation in chronic periodontitis. Findings indicated elevated levels of Prx1 and Prx2 in periodontitis, with significant associations between Prx expression and oxidative stress markers. Prx1 demonstrated a cytoprotective role by eliminating reactive oxygen species, whereas Prx2 levels decreased following non-surgical periodontal therapy by 30%–40%. Smoking was identified as a confounding factor affecting redox homeostasis and disease activity. Conclusion: Peroxiredoxins, particularly Prx1 and Prx2, appear to play a significant role in maintaining redox homeostasis and modulating oxidative stress in chronic periodontitis. Although the available evidence is limited and heterogeneous, the findings suggest that these antioxidant proteins may serve as promising biomarkers and potential therapeutic targets. Further well-designed clinical and translational studies are required to validate their diagnostic and therapeutic applications in periodontal disease.