TY - JOUR AB - Sialoperoxidase and myeloperoxidase are the two main peroxidase enzymes found in the oral cavity. Sialoperoxidase is present in salivary secretions and in the biofilms that line the oral surfaces, while myeloperoxidase is abundant in the dento‑gingival sulcus area. In the presence of hydrogen peroxide (H2O2), oral peroxidases catalyze the oxidation of the pseudohalide anion thiocyanate (SCN) to hypothiocyanite (OSCN), a strong oxidant that serves an antimicrobial role. Furthermore, oral peroxidases consume bacteria‑produced H2O2 and could help inactivate toxic carcinogenic and genotoxic substances. Numerous in vitro studies have reported the antibacterial, antimycotic and antiviral role of peroxidases, suggesting possible applications in oral therapy. However, the use of oral hygiene products incorporating peroxidase systems has not yet been shown to be beneficial for the treatment or prevention of oral infections. This paradox reflects our incomplete knowledge of the physiological role of peroxidases in a complex environment, such as the oral region. While hygiene is crucial for restoring oral microbiota to a symbiotic state, there are no data to suggest that the addition of a peroxidase per se can create a dysbiotic state. Recent investigations have associated the presence of peroxidase activity with gram‑positive cocci microbial flora, and its insufficiency with dysbiosis has been linked to pathologies, such as caries, periodontitis or infections of the oral mucosa. Therefore, oxidants generated by oral peroxidases appear to be an essential ecological determinant for oral health through the selection of a symbiotic microbiota capable of resisting oxidative stress. The objective of the present review was to update the current knowledge of the physiological aspects and applications of oral peroxidases in clinical practice. AD - Faculty of Medicine, Université Libre de Bruxelles, B‑1070 Brussels, Belgium AU - Courtois,Philippe DA - 2021/07/01 DO - 10.3892/mmr.2021.12139 IS - 1 JO - Mol Med Rep KW - biofilm hypoiodite hypothiocyanite myeloperoxidase oral hygiene oral microflora salivary peroxidase PY - 2021 SN - 1791-2997 1791-3004 SP - 500 ST - Oral peroxidases: From antimicrobial agents to ecological actors (Review) T2 - Molecular Medicine Reports TI - Oral peroxidases: From antimicrobial agents to ecological actors (Review) UR - https://doi.org/10.3892/mmr.2021.12139 VL - 24 ER -