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Mercury (Hg) is a toxic metal that became a public health problem due to environmental contamination caused by anthropogenic activity. In this sense, oral homeostasis can undergo changes due to the toxic effects of metal on the salivary glands. Therefore, our objective was to investigate the proteomic and genotoxic changes in salivary glands after exposure to inorganic mercury (IHg). Forty Wistar rats that were divided into a control group, which received distilled water, and an exposed group, which received 0.375 mg/kg of mercury chloride for 45 days via orogastric gavage. After that, the animals were euthanized, and the parotid and submandibular glands were collected for analysis of the genotoxic effects, using the comet assay and proteome global profile assessment. The results showed that IHg promoted damage to cellular DNA associated with proteomic changes that showed events such as oxidative stress, mitochondrial dysfunction, changes in the cytoskeleton, and apoptosis. Therefore, these findings show a profile of molecular changes due to the interactions of IHg with several proteins and mechanisms inherent to the cell, which consequently may result in dysfunction of the salivary glands and impaired homeostasis of the oral cavity.

Made available in DSpace on 2022-04-29T08:45:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-09-27 Although fluoride (F) is well-known to prevent dental caries, changes in cell processes in different tissues have been associated with its excessive exposure. Thus, this study aimed to evaluate the effects of F exposure on biochemical, proteomic, and genotoxic parameters of submandibular glands. Twenty one old rats (n = 30) were allocated into three groups: 60 days administration of drinking water containing 10 mgF/L, 50 mgF/L, or only deionized water (control). The submandibular glands were collected for oxidative biochemistry, protein expression profile, and genotoxic potential analyses. The results showed that both F concentrations increased the levels of thiobarbituric acid–reactive substances (TBARS) and reduced glutathione (GSH) and changed the proteomic profile, mainly regarding the cytoskeleton and cellular activity. Only the exposure to 50 mgF/L induced significant changes in DNA integrity. These findings reinforce the importance of continuous monitoring of F concentration in drinking water and the need for strategies to minimize F intake from other sources to obtain maximum preventive/therapeutic effects and avoid potential adverse effects. Laboratory of Functional and Structural Biology Institute of Biological Sciences Federal University of Pará Laboratory of Clinical Immunology and Oxidative Stress Faculty of Pharmacy Institute of Health Sciences Federal University of Pará Section of Parasitology Evandro Chagas Institute Laboratory of Cell Culture and Cytogenetics Environment Section Evandro Chagas Institute Department of Biological Sciences Bauru School of Dentistry University of São Paulo Department of Chemistry University of Nebraska-Lincoln Department of Preventive and Restorative Dentistry School of Dentistry São Paulo State University (UNESP) Department of Preventive and Restorative Dentistry School of Dentistry São Paulo State University (UNESP)

Fluoride, a chemical compound naturally found in the environment, has been used in pharmaceutical industries, production of pesticides, and mainly added to dentifrices and public water supplies. Thus, humans might be exposed to several fluoride compounds. Despite the well known anticariogenic activity, the daily human intake of fluoridated water is extensively discussed due to the evidences of potential side effects after long-term exposure. Therefore, this chapter addresses both beneficial and detrimental effects of fluoride intake, provides relevant information on fluoride toxicity and oxidative biochemistry in living organisms, reports the pieces of evidence in literature, and emphasizes the consequences of a systemic imbalance between pro- and antioxidant agents.

Aluminum (Al) is one of the most found elements in nature in many forms, and human exposure can be quite common. Therefore, it is important to investigate the effects of exposure to Al mainly at low doses and for a prolonged period, in order to simulate human exposure in the periodontium, an important structure for support and protection of the teeth. This investigation aimed to study the aluminum chloride (AlCl3) toxicological effects in the mineral composition and micromorphology of the alveolar bone of rats. Two groups of eight male Wistar rats were used for the experiment. AlCl3 group was exposed to AlCl3 orally at a dose of 8.3 mg/kg/day for 60 days, while the control group received only distilled water. After that, the mandibles were collected and submitted to the following analyses: Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray microtomography analysis; blood was also collected for determination of Al circulating levels. Our data showed that AlCl3 was capable of increasing Al circulating levels in blood. It was able to promote changes in the mineral content and triggers significant changes in the mineralized bone microstructure, such as number and thickness of trabeculae, being associated with alveolar bone-loss.

This systematic review aims to evaluate the association between tooth loss and stroke. The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines were followed. The PECO strategy was used to limit the eligibility criteria. The following databases were used on searches: PubMed, Scopus, Web of Science, The Cochrane Library, LILACS and OpenGrey. We included observational studies performed in adults (Population), in which patients with tooth loss (Exposition) and patients without tooth loss (Comparison) were observed to investigate the association between tooth loss and stroke (Outcome). After searches, the results were submitted to a selection process, followed by data extraction, quality assessment and risk of bias evaluation. The certainty of the evidence was evaluated through GRADE approach. A total of 925 potential studies were retrieved by the searches and 9 were included in this review. Seven of the included articles described an association between tooth loss and stroke. Low risk of bias and a low certainty of the evidence were identified to all studies. The certainty of the evidence may be associated with the observational nature of the included studies. Even though an association between tooth loss and stroke was suggested, the low strength of the current evidence indicated the need for further investigations with a better methodological design to conclude this question.

Environmental and occupational mercury exposure is considered a major public health issue. Despite being well known that MeHg exposure causes adverse effects in several physiologic functions, MeHg effects on salivary glands still not completely elucidated. Here, we investigated the cellular MeHg-induced damage in the three major salivary glands (parotid, submandibular, and sublingual) of adult rats after chronic, systemic and low doses of MeHg exposure. Rats were exposed by 0.04 mg/kg/day over 60 days. After that, animals were euthanized and all three glands were collected. We evaluated total Hg accumulation, metallothionein I/II (MT I/II), α-smooth muscle actin (α-SMA), and cytokeratin 18 (CK18) immune expression. Our results have showed that MeHg is able to disrupt gland tissue and to induce a protective mechanism by MT I/II expression. We also showed that cell MT production is not enough to protect gland tissue against cellular structural damage seen by reducing marking of cytoskeletal proteins as CK18 and α-SMA. Our data suggest that chronic MeHg exposure in low-daily doses is able to induce cellular damage in rat salivary glands.