Lactoperoxidase is an integral part of the mammal natural defence system. It is a peroxidase enzyme secreted from mammary, salivary and other mucosal glands functions as a natural antibacterial enzyme. Lactoperoxidase is a member of the heme peroxidase enzymes and is encoded by the LPO gene in humans. It catalyzes the oxidation of several organic and inorganic substrate by hydrogen peroxide. These oxidised products produced through these reactions have potent bactericidal activities. It has a vital role in the innate immune system as it kills bacteria in milk and mucosal secretions hence may have therapeutic applications.
Clinical significance of Lactoperoxidase
- Innate immune system
Lactoperoxidase has antibacterial properties which play an essential role in the immune defence system. When lactoperoxidase works on thiocyanate and hydrogen peroxide by the reaction of dual oxidase 2 proteins, also known as Duox2, it produces one of the reactive intermediates called Hypothiocyanite. When a person suffers from cystic fibrosis, Thiocyanate secretion is decreased, resulting in a reduced production of antibacterial hypothiocyanite, which consequently increases the risk of airway infection. The lactoperoxidase system is not mutagenic; hence it does not harm the human DNA. However, under certain circumstances, the lactoperoxidase system may contribute to oxidative stress.
- Breast Cancer
Lactoperoxidase oxidises estradiol which leads to oxidative stress in breast cancer. It can start a chain reaction which leads to oxygen consumption and intracellular hydrogen peroxide accumulation which leads to hydroxyl radical-induced DNA base lesions female breast cancer tissue.
- Oral care
Lactoperoxidase supplement has clinical efficacy in a variety of oral care products. The application of lactoperoxidase is in caries, gingivitis, and periodontitis. A blend of lysozyme and lactoperoxidase can be useful in supporting the treatment of burning mouth syndrome (glossodynia). When combined with lactoferrin, lactoperoxidase combats halitosis; in combination with lactoferrin and lysozyme, lactoperoxidase helps to recover symptoms of xerostomia. Furthermore, gels with lactoperoxidase help to improve symptoms of oral cancer when saliva production is conceded due to irradiation. Also, the oral bacterial flora is influenced favourably in this condition.
Applications of lactoperoxidase
As lactoperoxidase is an effective antimicrobial agent like igg powder, hence it is used for preserving food, cosmetics and ophthalmic solutions. Furthermore, it is also used in dental and wound treatment. It may find application as anti-tumour and antiviral agents.
- Dairy Products
Lactoperoxidase is an effective antimicrobial agent hence is used in reducing bacterial microflora in milk and milk products. Lactoperoxidase system is activated by the addition of hydrogen peroxide and thiocyanate and it extends the shelf life of refrigerated raw milk. It is used as an indicator of over pasteurization of milk as it is heat resistant.
A mixture of lactoperoxidase, glucose, glucose oxidase (GOD), iodide and thiocyanate is used in the preservation of cosmetics.
- Cancer and viral infections
Antibody conjugates of glucose oxidase and to lactoperoxidase are effective in killing tumour cells in vitro. Besides, macrophages exposed to lactoperoxidase are stimulated to kill cancer cells.