Search results for "Lactoperoxidase"
showing 8 items of 8 documents
Interference of carbidopa and other catechols with reactions catalyzed by peroxidases
2018
Abstract Background A number of compounds, including ascorbic acid, catecholamines, flavonoids, p-diphenols and hydrazine derivatives have been reported to interfere with peroxidase-based medical diagnostic tests (Trinder reaction) but the mechanisms of these effects have not been fully elucidated. Methods Reactions of bovine myeloperoxidase with o-dianisidine, bovine lactoperoxidase with ABTS and horseradish peroxidase with 4-aminoantipyrine/phenol in the presence of carbidopa, an anti-Parkinsonian drug, and other catechols, including l -dopa, were monitored spectrophotometrically and by measuring hydrogen peroxide consumption. Results Chromophore formation in all three enzyme/substrate sy…
The effects of an amine fluoride/stannous fluoride and an antimicrobial host protein mouthrinse on supragingival plaque regrowth.
2004
BACKGROUND: Chlorhexidine (CHX)-containing mouthrinses are recommended as adjuncts to mechanical oral hygiene. The problem associated with side effects, however, has stimulated the search for alternative antiplaque agents. The aim of this study was to investigate the plaque inhibitory effects of two mouthrinses containing amine fluoride/stannous fluoride (ASF) and antimicrobial host proteins (lactoperoxidase, lysozyme and lactoferrin; LLL), respectively. METHODS: The study was an observer-masked, randomized 4x4 Latin square cross-over design balanced for carryover effects, involving 12 healthy volunteers in a 4-day plaque regrowth model. A 0.12% CHX mouthrinse and a saline solution served a…
The effects of sugar-free chewing gums on dental plaque regrowth: a comparative study
2006
Abstract Sugar-free chewing gum has been claimed to be a useful means of reducing dental plaque accumulation. The incorporation of additives, such as enzymes, abrasives and divalent metal ions, into gum formulations might improve their antiplaque activity, particularly at the buccal and lingual surfaces of the teeth. Objectives The aim of this study was to investigate the plaque inhibitory effects of three sugar-free chewing gums each containing lactoperoxidase (LP), micro granules of silicon dioxide (SD), and zinc gluconate (ZG). Methods The study was an observer-masked, randomized cross-over design balanced for carryover effects, involving 12 healthy volunteers in a 4-day plaque regrowth …
Melatonin activates the peroxidase-oxidase reaction and promotes oscillations.
2001
We have studied the peroxidase-oxidase reaction with NADH and O2 as substrates and melatonin as a cofactor in a semibatch reactor. We show for the first time that melatonin is an activator of the reaction catalyzed by enzymes from both plant and animal sources. Furthermore, melatonin promotes oscillatory dynamics in the pH range from 5 to 6. The frequency of the oscillations depends on the pH such that an increase in pH was accompanied by a decrease in frequency. Conversely, an increase in the flow rate of NADH or an increase in the average concentration of NADH resulted in an increase in oscillation frequency. Complex dynamics were not observed with melatonin as a cofactor. These results a…
Redox intermediates of plant and mammalian peroxidases: a comparative transient-kinetic study of their reactivity toward indole derivatives.
2002
Abstract A comparative study on the reactivity of five indole derivatives (tryptamine, N-acetyltryptamine, tryptophan, melatonin, and serotonin), with the redox intermediates compound I (k2) and compound II (k3) of the plant enzyme horseradish peroxidase (HRP) and the two mammalian enzymes lactoperoxidase (LPO) and myeloperoxidase (MPO), was performed using the sequential-mixing stopped-flow technique. The calculated bimolecular rate constants (k2, k3) revealed substantial differences regarding the oxidizability of the substrates by redox intermediates at pH 7.0 and 25°C. With HRP it was shown that k2 and k3 are mainly determined by the reduction potential (E°′) of the substrate with k2 bei…
Clinical efficacy of a bleaching enzyme-based toothpaste. A double-blind controlled clinical trial.
2015
Abstract Objectives To assess the efficacy of a bleaching enzyme-based toothpaste. Material and methods A randomized clinical trial was carried out, comprising 48 participants with teeth exhibiting color A3 or higher according to the Vita Classical guide. One-half of the sample received the bleaching enzyme-based toothpaste (White Kin ® ), while the other received placebo toothpaste. Both products were supplied in identical containers and had the same composition except for the active components. The teeth color was measured with a spectrophotometer. The patients were instructed to brush their teeth three times a day during 3 min with the assigned product, during 12 weeks. The color measure…
Gingival bleeding reduction using a carbamide peroxide based tooth paste with lactoperoxidase
2011
Introduction: The combination of carbamide peroxide, thiocyanate or enzymes such as amynoglucosidase or gluco-oxidase is able to reduce gingival inflammation. Objective: To evaluate antiseptic efficacy, in relation to reduced gingival bleeding, of a new dentifrice containing carbamide peroxide and lactorperoxidase. Materials and method: A sample of 32 patients, with periodontal pockets of more than 3mm in the vestibular area and 4 mm at interproximal sites, was divided into two groups of 16 and 17 patients respectively. Group A used a dentifrice containing 3% carbamide peroxide and 5% lactoperoxidase plus 0.022% sodium fluoride for three weeks followed by a control dentifrice with only 0.02…
Potential anticarcinogenic peptides from bovine milk.
2012
Bovine milk possesses a protein system constituted by two major families of proteins: caseins (insoluble) and whey proteins (soluble). Caseins (αS1,αS2,β, andκ) are the predominant phosphoproteins in the milk of ruminants, accounting for about 80% of total protein, while the whey proteins, representing approximately 20% of milk protein fraction, includeβ-lactoglobulin,α-lactalbumin, immunoglobulins, bovine serum albumin, bovine lactoferrin, and lactoperoxidase, together with other minor components. Different bioactivities have been associated with these proteins. In many cases, caseins and whey proteins act as precursors of bioactive peptides that are released, in the body, by enzymatic pro…