Antimicrobial effect of acidified nitrite on periodontal bacteria

Abstract

The antimicrobial agent nitric oxide (NO) is formed in the mouth and its concentration is directly related to salivary nitrite, which in turn is related to dietary nitrate intake. The aim of this study was to determine whether nitrite under acidic conditions will have an inhibitory effect, possibly occurring through NO production, on the periodontal disease pathogens Fusobacterium nucleatum, Eikenella corrodens and Porphyromonas gingivalis. Whereas the growth of these organisms was inhibited by a more acid pH, the addition of nitrite caused a marked, further dose-dependent reduction in bacterial numbers after exposure. The ability of these bacteria to recover from nitrite exposure was also affected by pH and nitrite concentration. At acidity levels below pH 5.0, low concentrations of nitrite (0.2 mM) caused effective complete killing of the periodontal bacteria. Addition of sodium thiocyanate did not increase the bacteriostatic or bacteriocidal activity of acidified nitrite against any of the 3 bacteria. These results demonstrate the possibility that nitrite in saliva, under appropriate conditions, may have an effect on the growth and survival of the bacteria implicated in periodontal disease.

Nitrates and Nitrites in meat products

“…The antimicrobial activity of nitrites in cured meat products is also enhanced from other antimicrobial hurdles such as heat treatment, pH, salt, water activity (a w ), redox potential and other curing ingredients (Tompkin, 2005). Several studies indicated that nitrites inhibit bacteria more effectively at low pH (Roberts, 2005;Allaker et al, 2001). Other components, such as ascorbate or isoascorbate / erythorbate and also cysteine, may enhance the antibotulinum efficacy of nitrites in cured meat by sequestering metal ions (Tompkin et al, 1978).…”

NADPH Oxidase Contributes to Resistance against Aggregatibacter actinomycetemcomitans-Induced Periodontitis in Mice

“…Various periodontopathogens, such as A. actinomycetemcomitans and P. gingivalis, have been shown to upregulate iNOS expression and NO production by a variety of cells, including mouse macrophages (37-39). Several reports reveal that NO is required for antimicrobial activity and immune modulation (40). Moreover, significantly increased iNOS expression by gingival macrophages, endothelial cells, and keratinocytes is observed in patients with periodontal disease, including localized aggressive periodontitis (41)(42)(43)(44)(45)(46).…”

Role of Nitric Oxide in Inflammatory Periodontal Diseases:

“…70 NO is formed in oral cavity of health individuals and its concentration is directly related to salivary nitrite, 71 which in turn is associated to dietary nitrate intake, and intraoral pH level. 72 It has been…”

“…72 However, some factors in saliva suppress the synthesis NO or destroy already produced NO. The most important molecule, which suppresses NO productions, is arginase in saliva.…”