Effects of long-term fluoride exposure are associated with oxidative biochemistry impairment and global proteomic modulation, but not genotoxicity, in parotid glands of mice

PLoS One. 2022 Jan 27;17(1):e0261252. doi: 10.1371/journal.pone.0261252. eCollection 2022.

Abstract

Background: Fluoride has become widely used in dentistry because of its effectiveness in caries control. However, evidence indicates that excessive intake interferes with the metabolic processes of different tissues. Thus, this study aimed to investigate the effects of long-term exposure to F on the parotid salivary gland of mice, from the analysis of oxidative, proteomic and genotoxic parameters.

Materials and methods: The animals received deionized water containing 0, 10 or 50 mg/L of F, as sodium fluoride, for 60 days. After, parotid glands were collected for analysis of oxidative biochemistry, global proteomic profile, genotoxicity assessment and histopathological analyses.

Results: The results revealed that exposure to fluoride interfered in the biochemical homeostasis of the parotid gland, with increased levels of thiobarbituric acid reactive species and reduced glutathione in the exposed groups; as well as promoted alteration of the glandular proteomic profile in these groups, especially in structural proteins and proteins related to oxidative stress. However, genotoxic assessment demonstrated that exposure to fluoride did not interfere with DNA integrity in these concentrations and durations of exposure. Also, it was not observed histopathological alterations in parotid gland.

Conclusions: Thus, our results suggest that long-term exposure to fluoride promoted modulation of the proteomic and biochemical profile in the parotid glands, without inducing damage to the genetic component. These findings reinforce the importance of rationalizing the use of fluorides to maximize their preventative effects while minimizing the environmental risks.

MeSH terms

  • Animals
  • Gene Expression Regulation / drug effects
  • Glutathione / metabolism
  • Lipid Peroxidation / drug effects
  • Male
  • Mice
  • Oxidation-Reduction
  • Parotid Gland / drug effects
  • Parotid Gland / metabolism*
  • Proteome / drug effects*
  • Proteomics / methods*
  • Sodium Fluoride / adverse effects*
  • Thiobarbituric Acid Reactive Substances / metabolism
  • Time Factors

Substances

  • Proteome
  • Thiobarbituric Acid Reactive Substances
  • Sodium Fluoride
  • Glutathione

Grants and funding

This study was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico – Brasil (CNPq) (grant no. 435093/ 2018-5) and the Coordination of Personal Improvement of Higher Education – (CAPES - Finance Code 001). The APC was funded by Pró-Reitoria de Pesquisa e Pós-graduação da Universidade Federal do Pará (PROPESP-UFPA). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.