Oral peroxidases: From antimicrobial agents to ecological actors (Review)

Abstract

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 (H 2 O 2 ), 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 H 2 O 2 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.

Neighboring Carboxylic Acid Boosts Peroxidase‐Like Property of Metal‐Phenolic Nano‐Networks in Eradicating Streptococcus mutans Biofilms

“…In nature, enzymes are widely involved in immune systems to eradicate the invading microbes, [ 17 ] and the peroxidase‐like reaction is one of the most commonly employed. For instance, salivary peroxidase uses H 2 O 2 to oxidize thiocyanate (SCN − ), [ 18 ] producing more lethal hypothiocyanite (OSCN − ) to eliminate pathogenic bacteria. However, natural enzymes are fragile in structures and of low cost‐effectiveness, limiting their clinical performance.…”

Salivary Redox Homeostasis in Human Health and Disease

“…It occurs in various forms (based on electrophoretic migration and molecular weight), but when salivary peroxidase is unbound, its molecular weight is approximately 78,000, and the isoelectric point is 8–10. In the oral cavity, it adsorbs different oral surfaces, such as enamel, salivary sediments, dental plaque, and bacteria, and at the same time retains its enzymatic activity [ 52 , 56 , 63 ]. Myeloperoxidase in the saliva is produced by the neutrophil’s lysis, where they undergo hypoosmotic shock and release myeloperoxidase together with other antimicrobial proteins-lysozyme and lactoferrin.…”

“…Myeloperoxidase in the saliva is produced by the neutrophil’s lysis, where they undergo hypoosmotic shock and release myeloperoxidase together with other antimicrobial proteins-lysozyme and lactoferrin. Myeloperoxidase is abundant in the dento-gingival sulcus area [ 63 ].…”

“…The primary function of salivary peroxidase and myeloperoxidase in the oral cavity is the oxidation of thiocyanate ion (SCN - ), which is derived from diet to hypothiocyanite (OSCN - ) with antibacterial activity, in the presence of hydrogen peroxide H 2 O 2 which is produced by oral bacteria and cells [ 19 , 52 , 56 , 62 , 63 , 64 ]. Furthermore, peroxidases present in human saliva consume bacteria-produced H 2 O 2 and could help inactivate some toxic carcinogenic, mutagenic, and genotoxic substances [ 63 , 64 ].…”

Medical Use of Polycatecholamines + Oxidoreductases-Modified Curdlan Hydrogels—Perspectives

“…Sialoperoxidase and myeloperoxidase found in the oral cavity can catalyze the oxidation of the pseudohalide anion thiocyanate (SCN-) to hypothiocyanite (OSCN-), which is a strong oxidant of antimicrobial role. This suggests possible applications of peroxidases in oral therapy [ 13 ].…”