Science
Mechanism of Action
Lactoperoxidase (LPO) functions as a peroxidase enzyme, catalyzing the oxidation of specific molecules, such as thiocyanate (SCN⁻), in the presence of hydrogen peroxide (H₂O₂). This reaction generates potent antimicrobial products, primarily hypothiocyanite (OSCN⁻). OSCN⁻ interacts with sulfhydryl (-SH) groups in microbial proteins, thereby inhibiting essential metabolic pathways like glycolysis, which results in a bacteriostatic effect. This action helps to restore a healthy skin microbiome by inhibiting pathogenic bacteria such as *Cutibacterium acnes* and *Staphylococcus aureus*, promoting improved skin health and barrier function.
Research
Clinical Evidence
Medium confidenceN/A
Transparency
Dusting Analysis
The Formula
Formulation
Stability
Lactoperoxidase is generally stable down to pH 3.0, but its stability may decrease in acidic environments around pH 5.3, potentially due to the release of crucial calcium ions. It can be irreversibly inactivated by an excess of hydrogen peroxide, and by light exposure in the presence of riboflavin and oxygen. The stability of its active product, hypothiocyanite (OSCN⁻), is also influenced by metal ions (e.g., Fe, Ni, Cu, Mn), light, pH, glycerol, and ammonium sulfate.
Conflicts
- Excess hydrogen peroxide
- Light in the presence of riboflavin and oxygen
- Metal ions (Fe, Ni, Cu, Mn) can affect the stability of the active product (OSCN⁻)
- Zinc compounds may inhibit peroxidase activity
Safety
Safety Profile
Lactoperoxidase is considered safe for cosmetic use, with Environment Canada classifying it as not expected to be toxic or harmful. The Lactoperoxidase System (LPS) has been designated as Generally Recognized As Safe (GRAS) by the FDA for use as a processing aid in dairy products at levels up to 300 mg/L. Its components are naturally present in human and animal secretions, suggesting a low risk of novel exposure. While some *in vitro* studies in oral contexts suggested potential cytotoxic effects, these findings necessitate further *in vivo* investigation for comprehensive safety assessment in skincare applications.
Your Skin
Skin Compatibility
Our Assessment
Verdict
Lactoperoxidase is a valuable enzymatic ingredient, leveraging its natural antimicrobial properties to effectively rebalance the skin microbiome, reduce *Cutibacterium acnes*, and improve overall skin health for all skin types.
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