Assessment of effects of mouthwash by Buccal Micronucleus Cytome Assay: a Preliminary Study

Abstract

-Mouthwashes are the most common antiseptic used for buccal hygiene. However, some studies have shown that these compounds containing alcohol can induce genotoxic and carcinogenic effects. The human buccal micronucleus cytome assay (BMCyt) has been used widely to investigate biomarkers for DNA damage, cell death, cytockinesis defects and basal cell frequency in buccal cells. Thus, the aim of this study was to assess whether the mouthwashes could induce genetic damage in exfoliated cells of the buccal epithelium by BMCyt. Sixty individuals participated of this study, divided in two groups: one, exposed to mouthwashes (n = 30), and another, not exposed (control group; n = 30). Nuclear damage (micronucleus and nuclear buds), incomplete cytokinesis (binucleated cells), cell death (condensed chromatin, karyorrhectic, pyknotic and karyolytic cells) and basal cells were evaluated in epithelium cells using image analysis at x1,000 magnification. The results showed a significant increase of nuclear buds, pyknotic and basal cells in exposed group. We observed that the composition of alcoholic products can be related to the micronucleus and nuclear bud cells frequencies, according to the following order: Listerine® > Colgate® > Oral B®. However, studies with a larger numbers of individuals are need to support the preliminary findings presented here. Keywords -Mouthwash. Micronucleus. Cellular death. Genotoxicity. BMCyt Assay.Resumo -Os enxaguatórios bucais são os antissépti-cos mais utilizados para a higiene bucal. No entanto, alguns estudos demonstraram que estes compostos que contém álcool podem induzir efeitos genotóxi-cos e carcinogênicos. O ensaio de micronúcleos em células da mucosa bucal (BMCyt assay) de humanos tem sido amplamente utilizado para investigar biomarcadores para avaliação de danos no DNA, morte celular, defeitos na citocinese e frequência de células basais em células bucais. Assim, o objetivo deste estudo foi avaliar se os enxaguatórios poderiam induzir danos genéticos em células esfoliadas do epitélio bucal pelo ensaio BMCyt. Participaram do estudo 60 indivíduos, divididos em dois grupos: um grupo exposto aos enxaguatórios (n = 30) e outro não exposto (grupo controle, n = 30). Os danos nucleares (micronúcleos e brotos nucleares), citocineses incompletas (células binucleadas), morte celular (células com cromatina condensada, cariorréxis, picnóticas e cariolíticas) e células basais foram avaliados em células de epitélio usando análise de imagem com aumento de 1.000x. Os resultados mostraram um aumento significativo de células com brotos nucleares, picnóticas e basais no grupo exposto. Observamos que a composição de enxaguantes contendo álcool pode estar relacionada às frequências de micronúcleos e de células com brotos nucleares, de acordo com a seguinte ordem: Listerine®> Colgate®> Oral B®. No entanto, estudos com um maior número de indivíduos são necessários para sustentar os resultados preliminares aqui apresentados.

Mouthwash use and oral cancer: a systematic review and meta-analysis

“…In this context, the authors found an increased frequency of micronuclei and cellular abnormalities in the group exposed to the alcohol-containing mouthwash. Due to the superficial and intracellular characteristics of the oral mucosa epithelium, the detection of DNA damage and cell death in desquamated epithelial cells requires the genotoxic agent to overcome the permeability barrier of the basal layer and induce DNA damage, later converting them into micronuclei during cell division 76 . The correlation between the number of stem cell divisions that occurred in a tissue during a person's life and the risk of cancer diagnosis in that tissue is highly positive and statistically significant 77 .…”

Avaliação de micronúcleos e outras alterações nucleares em células esfoliadas da mucosa bucal de indivíduos expostos direta e indiretamente aos agrotóxicos

“…Células esfoliadas da mucosa bucal dos indivíduos foram coletadas de acordo com Hernandes et al (2016). As células foram centrifugadas para lavagens sucessivas com solução Carnoy (etanol/ácido acético; 3:1), para a retirada de micro-organismos e resíduos indesejáveis.…”

“…The questionnaire contained questions about age, type and time of exposure, prevalence of family cancer, and other relevant information to assess the relationship with cell damage. Cell collection was performed according to Hernandes et al (2016), using the micronucleus test (MN) and other nuclear alterations, to identify the frequency of cells with DNA damage, dead cells and cytotoxicity. The results showed a higher frequency of MN and dying cells in the group of farmers and, less frequently, in the group of consumers of conventionally produced foods, compared to the control group.…”