La importancia de evaluar el daño al DNA / The Importance of Assessing DNA Damage

Resumen Se calcula que el cuerpo humano está conformado por billones de células, las cuales sufren cientos de miles de lesiones al día en su DNA. Aunque el DNA no es la única biomolécula que sufre daños, su importancia radica en que es la única que no puede ser sustituida por la célula, así que, cuando esta sufre daños, la célula debe repararlos, tolerarlos o, en el caso extremo, activar las vías que la llevarán a la muerte, ya que lo importante es mantener la integridad celular y la homeostasis del organismo. Hay miles de agentes que pueden dañar al DNA, algunos los produce la misma célula y se les denomina 'agentes endógenos', mientras que otros son agentes externos y se les conoce como 'agentes exógenos'. La célula no puede evitar el daño causado por los agentes endógenos, ya que son productos de la actividad metabólica, por ejemplo; así que, cuando suceden se activan de forma inmediata los mecanismos celulares para mitigarlos. Lo mismo pasa con los daños causados por agentes exógenos, ya que la célula hará todo lo posible por disminuir los efectos adversos que pueden causar. El problema se pone de manifiesto cuando la célula no puede reparar los daños o los repara mal o son tantos que los mecanismos de reparación se ven rebasados, es entonces cuando el daño permanece en el DNA y se genera un estado de inestabilidad cromosómica que puede conducir a la célula a la disfunción y a la malignización. Este estado de inestabilidad cromosómica se puede ver reflejado en el aumento de rompimientos de DNA o de micronúcleos en las células expuestas, lo que se puede cuantificar por medio de métodos especiales como el 'Ensayo Cometa' y el 'Ensayo de Micronúcleos', ya que identificar el daño en el DNA es una forma de evaluar el potencial tóxico que tienen los agentes a los que están expuestas las poblaciones, permite conocer los mecanismos de acción que tienen y, además, ayuda a comprender los factores que influyen en el detrimento de la salud poblacional.

Abstract It is estimated that the human body is made of trillions of cells, which suffer hundreds of thousands of DNA lesions every day. Although DNA is not the only biomolecule that suffers damage, its importance lies in the fact that it is the only biomolecule that cannot be replaced by the cell, so when it suffers damage, the cell must repair it, tolerate or, in a extreme case, activate pathways that will lead to death, since the objective is to maintain cell integrity and the homeostasis of the organism.There are thousands of agents that can damage DNA, some are produced by the cell and are called 'endogenous, while others are external agents and are known as 'exogenous. The cell cannot avoid the damage caused by endogenous agents, since they are products of its metabolic activity, for example, so when they occur, cellular mechanisms are immediately activated to mitigate them. The same happens with the damage caused by exogenous agents, since the cell will do everything possible to diminish the adverse effects they can cause. The problem becomes apparent when the cell is unable to repair the damage or poorly repairs it, or repairs so much that the mechanisms are overwhelmed, when the damage remains in the DNA and a state of chromosomal instability is generated that can lead the cell to dysfunction and malignization. This state of chromosomal instability can be reflected in increased DNA breaks or micronuclei in exposed cells, which can be quantified by special methods such as the 'Comet Assay' and the 'Micronucleus Assay'. Since identifying DNA damage is a way of evaluating the toxic potential of the agents to which populations are exposed, it allows us to know their mechanisms of action and helps to understand the factors that influence the detriment in population's health.

Biomonitoring of air quality in the Bodoquena microregion, Mato Grosso Do Sul: mutagenic and morphoanatomical alterations in Tradescantia pallida (rose) D.R. Hunt var. purpurea

Abstract The objective of this study was to assess air quality in relation to vehicular traffic flow in cities located at different elevations in the Bodoquena microregion, state of Mato Grosso do Sul, Brazil. To do so, a micronucleus test was carried out using the TRAD-MCN bioassay on young Tradescantia buds collected from February to November 2018 in seven cities of the microregion with different traffic flow intensities. Meteorological parameters were evaluated, and vehicular traffic was counted to determine traffic flow in each city. With data from the Shuttle Radar Topography Mission (SRTM) and processing in Esri ArcGIS® software version 10.5.1, the regions was mapped based on an Elevation Model. Morphoanatomical analyses were performed according to standard methodology. Measurements were taken of thickness, length and width of tissues and structures, including the upper and lower cuticle, upper and lower epidermis, hypodermis and mesophyll. The greatest traffic flow was found in the cities of Bodoquena, Guia Lopes da Laguna, Jardim, and Porto Murtinho, with the period from 5:00 to 6:00 p.m. showing the highest traffic flow. The greatest frequency of mutagenic alterations was found in the city of Guia Lopes da Laguna, although the results did not differ significantly from Bonito, Caracol, and Jardim. Throughout the biomonitoring, the summer and autumn seasons showed the greatest micronuclei frequencies in all evaluated cities. Variations in the tissue/structure thickness was observed across cities and seasons, but with a decrease in thickness during autumn. In general, the tissues/structures were smaller for the cities of Nioaque and Porto Murtinho, while the anatomical and morphological characteristics of leaf length and thickness showed no differences among cities. We found limited correlation between micronuclei frequency and traffic flow, supporting the hypothesis that although mutagenic alterations are observed in T. pallida, in this microregion the changes are numerically lower when compared to other regions of the state. In light of the genotoxic and morphoanatomical factors assessed herein, the Bodoquena microregion appears to be well preserved in terms of air quality, presenting low micronuclei frequency and a limited reduction in tissues and leaf structures, regardless of the season.

Resumo O objetivo deste trabalho foi avaliar a qualidade do ar com base no fluxo veicular das cidades localizadas em diferentes altitudes na microrregião da Bodoquena, no estado de Mato Grosso do Sul, Brasil. Para tal, foi realizado o teste de micronúcleo, por meio do bioensaio TRAD-MCN em botões jovens de Tradescantia coletadas no período entre fevereiro a novembro de 2018 em sete cidades da microrregião da Bodoquena, com diferentes intensidades de fluxo veicular. Foram avaliados os parâmetros meteorológicos, os veículos foram contados para determinar o tráfego de veículos em cada cidade e altitude. A partir da topografia Shuttle Radar (SRTM) e processamento no software Esri ArcGIS® versão 10.5.1 foi possível mapear a área com base no Modelo de Elevação. As análises morfoanatômicos foram realizadas conforme metodologia padrão. As mensurações de espessura, comprimento, largura dos tecidos e estruturas como a cutícula superior, cutícula inferior, face superior e face inferior da epiderme, hipoderme e mesófilo foram avaliadas. O maior fluxo veicular foi encontrado nas cidades de Bodoquena, Guia Lopes da Laguna, Jardim e Porto Murtinho. O horário das 17:00 às 18:00h foi o que apresentou maiores fluxo de veículos. A maior frequência de alterações mutagênicas foi encontrada na cidade de Guia Lopes, não diferindo de Bonito, Caracol e Jardim. Ao longo do biomonitoramento observou-se que as estações de verão e outono foram as que apresentaram maiores frequências de micronúcleo independente da cidade avaliada. Observou-se que a correlação entre a frequência de micronúcleos e o fluxo veicular foi baixa, apoiando a tese de que essa microrregião, embora apresente alterações mutagênicas em T. pallida, as alterações numericamente são pequenas quando comparadas a outras regiões do estado de Mato Grosso do Sul. Observou-se uma variação na espessura dos tecidos/estruturas que é variável entre as diferentes cidades e estações do ano. De forma geral os tecidos/estrutura apresentaram redução na espessura para as cidades de Nioaque e Porto Murtinho quanto aos aspectos anatômicos e morfológicos, sendo que, para o comprimento e espessura foliar não foi observado diferenças entre as cidades. Em relação as estações do ano, observou-se que no outono a espessura dos tecidos/estruturas são menores. Diante dos fatores genotóxicos e morfoanatômicos aqui avaliados, a microrregião da Bodoquena parece estar bem preservada em termos de qualidade do ar, apresentando baixa frequência de micronúcleos e redução limitada de tecidos e estruturas foliares, independentemente da estação do ano.

Estudio comparativo de biomonitoreo citogenético en personal veterinario expuesto ocupacionalmente a radiaciones ionizantes mediante el ensayo de micronúcleos con bloqueo de la citocinesis

Introducción: las radiaciones ionizantes (RI) pueden inducir la formación de micronúcleos (MN). La frecuencia de MN se utiliza como biomarcador de daño genético inducido por (RI). Objetivo: evaluar el daño al ADN resultante de la exposición ocupacional a RI en personal de clínicas veterinarias o afines. Metodología: se utilizó el ensayo de micronúcleos con bloqueo de la citocinesis (MNBC) para comparar la frecuencia observada del biomarcador en 40 individuos expuestos ocupacionalmente a RI con respecto a un grupo control de 32 participantes, ambos grupos pertenecen a personal veterinario. Además, se registraron variables demográficas, de estilo de vida y ocupacionales que pudieran influir en la formación de MN. Resultados: el análisis univariado no registró diferencias significativas en la frecuencia de MN entre los grupos de estudio (p=0,118). Mediante análisis multivariado se obtuvo que aproximadamente un 27% (R2 ajustado= 0,269) de la variabilidad de la frecuencia de MN puede explicarse por la influencia conjunta de la edad, el sexo y el número de radiografías realizadas por el individuo. La edad es la variable de mayor importancia relativa (β = 0,504), seguida del sexo del participante (β = -0,316) y el número de radiografías realizadas por día (β = 0,214). Conclusiones: La frecuencia de MN tiende a aumentar en mujeres, a medida que aumenta la edad del participante y a mayor número de radiografías realizadas.

Introduction: Ionizing radiation (RI) can induce the formation of micronuclei (MN). The formation of MN is used as a biomarker of radiation-induced genetic damage. Objective: assess DNA damage resulting from occupational exposure to RI in veterinary personnel. Methodology: the cytokinesis-block micronucleus assay (MNBC) was used to compare the observed frequency of MN in 40 individuals occupationally exposed to ionizing radiation with respect to a control group of 32 participants, both groups belonging to veterinary personnel. In addition, demographic, lifestyle and occupational variables that could influence the formation of MN were recorded. Results: univariate analysis did not show significant differences in the frequency of MN between the study groups (p=0.118). Using multivariate analysis, it was found that approximately 27% (adjusted R2= 0.269) of the variability in the frequency of MN can be explained by the joint influence of age, sex and the number of radiographic images performed by the participant. Age is the variable with the greatest relative importance (β = 0.504), followed by the sex of the participant (β = -0.316) and the number of X-rays performed per day (β = 0.214). Conclusions: the frequency of MN tends to increase in women, as the participant's age increases and as the number of radiographic images performed increases.

Ensayo de micronúcleos con bloqueo de la citocinesis como biomarcador de daño genético en poblaciones sobreexpuestas a radiaciones ionizantes / Micronucleus assay as biomarker of DNA damage in population exposed to ionizing radiation

Resumen Introducción: las radiaciones ionizantes (RI) son capaces de perjudicar el ADN; para evaluar este fenómeno es posible utilizar la formación de micronúcleos como biomarcador de efecto temprano del daño radioinducido. El ensayo de micronúcleos con bloqueo de la citocinesis (MNBC) es una técnica citogenética que permite demostrar el impacto de agentes genotóxicos. Propósito: en el presente trabajo se describieron mecanismos moleculares involucrados en la radioinducción de micronúcleos, la técnica del MNBC, los criterios de análisis, sus aplicaciones dentro de la investigación biológica y su extensión a la clínica, con énfasis en su empleo como biomarcador del daño genético en grupos sobreexpuestos a RI. Argumentos para la discusión: el MNBC se considera un método confiable, simple y rápido y existe evidencia de su aplicabilidad para el estudio de los efectos biológicos en casos de riesgo ocupacional y en accidentes radiológicos aislados o a gran escala. Conclusiones: el MNBC es una herramienta valiosa que posibilita estimar las consecuencias por dosis bajas de RI en poblaciones involucradas y, a la vez, orientar la toma de decisiones en cuanto a su prevención o atenuación . De igual forma, puede ser utilizado en análisis del campo de la radiobiología, a fin de detallar las incidencias de las radiaciones ionizantes sobre el ADN.

Abstract Introduction. Ionizing radiation (IR) is capable of causing DNA damage. For the evaluation of this phenomenon it is possible to use chromosomal aberrations as biomarkers. The Cytokinesis-Block Micronucleus assay (CBMN) is a cytogenetic technique that allows to demonstrate the effect of genotoxic agents.Proposition:in the present review, we will describe the molecular mechanisms involved in micronucleus radioinduction, the micronucleus technique and criteria for analysis, its applications within biological research and its extension in clinical research, with emphasis on its application as a biomarker of radioinduced genetic damage. Arguments for discussion: the CBMN is considered a reliable, simple and fast technique and there is evidence of its applicability in the evaluation of biological effects in occupationally exposed personnel and in isolated or large-scale radiological accidents. Conclusions: the CBMN a valuable tool in estimating radiological risk in populations exposed to low doses of IR, allowing to guide decision-making regarding prevention or mitigation of exposure to IR in populations involved. Similarly, the cbmn can be used in research in the field of radiobiology, as a means to describe the effects of ionizing radiation on DNA.

Efecto genotóxico de ranitidina sobre el ADN de eritrocitos policromáticos de Rattus novergicus cepa Holtzman / Genotoxic effect of ranitidine on the DNA of polychromatic erythrocytes of Rattus norvegicus strain Holtzman

Introducción: La ranitidina es un fármaco que esta asociado a mutagénesis por generar alteraciones genéticas y/o carcinogenesis celular pero se desconoce su rol a nivel genotóxico en eritrocitos policromáticos. Por tanto, se investigó el efecto de ranitidina sobre el ADN en eritrocitos policromáticos micronucleados (EPC) en ratas albinas (Rattus novergicus, cepa Holtzman) mediante el test de micronúcleos. Materiales y métodos: Se estudiaron cuatro grupos de ratas: control negativo con suero salino fisiológico (0,5 ml por 15 días); control positivo con ciclofosfamida (dosis 50 mg/kg por 2 días) y dos grupos experimentales tratados con ranitidina (dosis 2 y 4 mg/kg por 15 días). Las ratas se sometieron a eutanasia y se obtuvo preparados citológicos con tinción de giemsa 5 % por 30 min. Resultados: Se encontró un aumento del tamaño e incremento significativo del número de micronúcleos en los EPC de 285 ± 10 de los grupos experimentales con una dosis de 4 mg/kg; así mismo, en comparación al control negativo con 70 ± 6. El índice de genotoxicidad fue tres veces mayor en los grupos experimentales (12,10 ± 0.49; 2 mg/kg RNT y 14,26 ± 0,51; 2 mg/kg RNT) en relación al control negativo (3,52 ± 0,32). Conclusiones: La ranitidina genera un estímulo creciente del índice genotóxico con elevada frecuencia de micronúcleos en EPC de R. norvegicus cepa Holtzman.

Background:Ranitidine is a drug that is associated with mutagenesis by generating genetic alterations and / or cell carcinogenesis, but its genotoxicity in polychromatic erythrocytes is unknown. Therefore, the effect of ranitidine on DNA of micronucleated polychromatic erythrocytes (EPC) in albino rats (Rattus norvegicus,Holtzmanstrain)wasresearchedbythemicronucleustest. Materials and methods: Four groups of rats were studied: negative control with physiological saline solution (0.5 ml for 15 days); positive control with cyclophosphamide (dose 50 mg / kg for 2 days) and two experimental groups treated with ranitidine (doses 2 and 4 mg / kg for 15 days). The rats were euthanized and cytological preparations were obtained by 30 min staining in 5% giemsa. An increase in the size and significant increase in the number Results:of micronuclei in the EPC was found in the experimental groups of 285.27 ± 10.25, compared to the negative control of 70.38 ± 6.47. The genotoxicity index was three times higher in the experimental groups (12.10 ± 0.49; 2 mg / kg NRTand 14.26 ± 0.51; 2 mg / kg NRT) in relation to the negative control (3.52 ± 0 , 32). Ranitidine generates an increasing stimulus of the genotoxic Conclusions:index with a high frequency of micronuclei in EPC of R. norvegicusstrain Holtzman

Tartrazina induce genotoxicidad en linfocitos de BALB/c Mus musculus / Tartrazine induces genotoxicity in BALB/c Mus musculus lymphocytes

RESUMEN Objetivos. Determinar el efecto genotóxico de la tartrazina en linfocitos de sangre periférica de Mus musculus BALB/c. Materiales y métodos. Se realizó un estudio experimental, a través de cinco grupos, con cinco ratones en cada uno. Se les registró el peso durante 17 semanas y, en la semana 15 se les administró suero fisiológico (control negativo), dicromato de potasio 25 mg/kg de peso corporal (pc) (control positivo) y tartrazina a dosis de 0,75 mg/kg pc, 7,5 mg/kg pc y 75 mg/kg pc, durante siete días, a excepción del control positivo que fue en dosis única. Luego, cada 24 h se obtuvo una muestra de sangre periférica de la cola y se realizó el frotis, secado y coloración. Posteriormente, se realizó el conteo de 1000 linfocitos por muestra de cada ratón, en todos los tratamientos. Resultados. Los tres tratamientos con tartrazina no causaron diferencias significativas en el peso de ratones a la semana 15, pero sí produjeron diferencias significativas en la frecuencia de linfocitos micronucleados, siendo el tratamiento con tartrazina de 75 mg/kg pc el de mayor efecto genotóxico, induciendo un promedio de 1,63 ± 0,08 linfocitos micronucleados, comparado con el control positivo que generó un promedio de 1,42 ± 0,08 linfocitos micronucleados. Conclusiones. La tartrazina produjo un efecto genotóxico, incrementando el número de linfocitos micronucleados, a dosis de 0,75; 7,5 y 75 mg/kg pc y no afecta el peso corporal durante siete días de administración en M. musculus BALB/c.

ABSTRACT Objectives. To determine the genotoxic effect of tartrazine on peripheral blood lymphocytes of BALB/c Mus musculus. Materials and methods. An experimental study was carried out using five groups, with five mice in each group. Their weight was registered for 17 weeks, and at week 15 they were administered physiological saline solution (negative control), potassium dichromate at 25 mg/kg body weight (bw) (positive control) and tartrazine at doses of 0.75 mg/kg bw, 7.5 mg/kg bw and 75 mg/kg bw, for seven days, with the exception of the positive control which was a single dose. Then, every 24 hours, a peripheral blood sample was obtained from the tail, which was then smeared, dried and stained. Subsequently, 1000 lymphocytes were counted for each sample from each mouse, for all treatment groups. Results. The three tartrazine treatments did not cause significant differences in the weight of mice at week 15, but did produce significant differences in the frequency of micronucleated lymphocytes, with the 75 mg/kg bw tartrazine treatment having the greatest genotoxic effect, inducing an average of 1.63 ± 0.08 micronucleated lymphocytes, compared to the positive control which obtained an average of 1.42 ± 0.08 micronucleated lymphocytes. Conclusions. Tartrazine produced a genotoxic effect, increasing the number of micronucleated lymphocytes, at doses of 0.75; 7.5 and 75 mg/kg bw and did not affect body weight during seven days of administration to BALB/c M. musculus.

Evaluación de efectos citotóxicos y genotóxicos con ensayo de micronúcleos en la mucosa bucal de pacientes con aparatología ortodóncica. Revisión de la literatura / Evaluation of cytotoxic and genotoxic effects with micronucleus test in the oral mucosa of patients with orthodontic appliances. Review of the literature

Las maloclusiones representan un problema de salud bucodental, que se resuelven mediante la colocación de aparatología ortodóncica fija (AOF). Esta aparatología provoca corrosión y liberación de iones metálicos por las aleaciones que la constituyen y por el tiempo prolongado del tratamiento. El objetivo de este trabajo fue analizar las alteraciones citotóxicas y genotóxicas de las células de la mucosa oral provocadas por el uso de AOF, reportadas en la literatura y evaluadas con ensayo de micronúcleos (MN); el cual es uno de los ensayos más utilizados para identificar el daño al ácido desoxirribonucleico (ADN). Se realizó una revisión de la literatura de los últimos 10 años, donde se incluye- ron nueve estudios, el 55% de estos mostró evidencia de daño citotóxico y genotóxico posterior a la terapia ortodóncica. El promedio de incremento de MN debido al uso de AOF en estos estudios, fue tres veces mayor con respecto a las células bucales sin trata- miento, este dato es similar a reportes de células orales precancerosas investigadas por otros autores. Además los artículos evaluados, reportaron alteración celular a partir de la primera semana de la colocación de los dispositivos y señalaron que hay una disminu- ción del daño con el tiempo de exposición. En conclusión, el ensayo de MN utilizado en la cavidad bucal demostró ser útil para detectar alteraciones en el ADN debido al uso de AOF. Los datos analizados permiten a los ortodoncistas implementar mejoras en la terapéutica ortodóncica.

Malocclusions represent an oral health problem, which is resolved by the placement of fixed orthodontic appliances (FOA). This orthodontic appliance causes corrosion and release of metal ions due to the alloys they constitute and due to the prolonged time of treatment. The objective of this work was to analyze the cytotoxic and genotoxic altera- tions from oral mucosa cells, caused by the use of FOA, reported in the literature and evaluated with micronucleus (MN) test, which is one of the most widely used tests to identify damage to deoxyribonucleic acid (DNA). A review of the literature of the last 10 years was carried out, where nine studies were included, 55% of these studies showed evidence of cytotoxic and genotoxic damage after orthodontic therapy. The increased average in MN due to the use of FOA in these studies, represent values of approximately three-fold more respect to oral cells without treatment, this data is similar to reports of precancerous oral cells that have been reported by other authors. Besides, the articles analyzed reported cell alterations after the first week of the devices placement and indica- ted a decrease in damage with exposure time. In conclusion, the MN test used in the oral cavity was useful in detecting DNA alterations due to the use of FOA. The data analyzed allow orthodontists to implement improvements in orthodontic therapy.

Micronucleus in exfoliated buccal cells of crack users: systematic review and meta-analysis / Micronúcleos en células bucales exfoliadas en consumidores de crack: una revisión sistemática y meta-análisis

Abstract This research aimed to conduct a systematic review and metanalysis to compare the frequency of cell damage in crack users and nonusers, through Micronucleous (MN) test in buccal mucosa cells. A comprehensive search was carried out on MEDLINE via PubMeb, Web of Science, LILACS and the grey literature without restrictions. It was included case-control studies that report the frequency of micronuclei in the oral mucosa of adult crack users and nonusers. A review protocol was registered with PROSPERO (CRD42018115672), and conducted in accordance with the PRISMA guidelines for the report of this systematic review. Furthermore, study quality was evaluated using an adapted Newcastle-Ottawa Scale for cross-sectional studies.The original search yielded 27 references, after eligibility criteriaonly five articles were included. The number of micronuclei was higher in crack users compared to nonusers. Also, secondary outcomes: binucleated cells, nuclear buds, pyknosis, karyorrhexis and karyolysis had higher prevalence in crack users.Crack use is associated with genotoxic and mutagenic effects because there is a higher frequency of micronuclei in exfoliated cells of crack users. In addition, MN test proved to be a goodbiomarker to assess the mutagenic impact of crack use in oral epithelium.

Resumen Esta investigación tuvo como objetivo realizar una revisión sistemática y un meta-análisis para comparar la frecuencia de daño celular en usuarios de crack y sin crack, a través de la prueba de micronúcleos (MN) en células de la mucosa bucal. Se realizó una búsqueda exhaustiva en MEDLINE a través de PubMeb, Web of Science, LILACS y la literatura gris sin restricciones. Se incluyeron estudios de casos y controles que informaron la frecuencia de micronúcleos en la mucosa oral de usuarios adultos de crack y sin crack. Se registró un protocolo de revisión con PROSPERO (CRD42018115672), y se realizó de acuerdo con las pautas de PRISMA para el informe de esta revisión sistemática. Además, la calidad del estudio se evaluó mediante una escala Newcastle-Ottawa adaptada para estudios transversales. La búsqueda original arrojó 27 referencias, después de los criterios de elegibilidad se incluyeron un total de cinco artículos. El número de micronúcleos fue mayor en los usuarios de crack en compa ración con los usuarios sin crack. Además, los resultados secundarios de células binucleadas, yemas nucleares, picnosis, cario- rrexis y cariólisis tuvieron una mayor prevalencia en los usuarios de crack. El uso de crack se asocia con efectos genotóxicos y mutagénicos porque hay una mayor frecuencia de micronúcleos en las células exfoliadas de los usuarios de crack. Además, la prueba de MN demostró ser un buen biomarcador para evaluar el impacto mutagénico del uso de crack en el epitelio oral.

Análise dos efeitos do glifosato e sua formulação Roundup® nas células e gônadas dos peixes Danio rerio (Cyprinidae) / Analysis of the effects of glyphosate and its formulation Roundup® on the cells and gonads of fish Danio rerio (Cyprinidae)

Os herbicidas estão entre os insumos químicos mais utilizados na agricultura e apresentam ação toxicológica para as plantas. Dentre os herbicidas existentes, o glifosato e a sua formulação comercial Roundup® são os mais utilizados devido à eficácia no controle de ervas daninhas. Entretanto, estudos sugerem que estes herbicidas podem provocar distúrbios a organismos aquáticos, principalmente o Roundup®, que além do glifosato ativo, apresenta na composição componentes surfactantes que aumentariam o seu potencial toxicológico para os seres vivos. Desta forma, o presente estudo teve como objetivo comparar o potencial mutagênico e desenvolvimento gonadal do princípio ativo glifosato e sua formulação Roundup® em peixes Danio rerio. Para isso, exemplares adultos de D. rerio permaneceram em aquários expostos à concentração de 65 µg/L de cada herbicida. Foram realizadas contagens de micronúcleos, calculado o índice gonadossomático (IGS) e verificado os estágios de maturação gonadal. Os resultados demonstraram que os peixes expostos aos herbicidas apresentaram aumentos significativos na frequência de micronúcleos, bem como no IGS, e maior ocorrência de ovários com estágios em maturação e maduros. Não foram verificadas diferenças significativas na comparação dos herbicidas, exceto um aumento na frequência de ovários maduros nas fêmeas expostas ao glifosato. Observou-se que, mesmo em pequenas concentrações, os herbicidas poderiam ter ocasionado efeitos nocivos para os peixes D. rerio, podendo induzir efeitos clastogênicos nos eritrócitos, assim como distúrbios reprodutivos, aumentando a preocupação sobre os impactos que estes herbicidas podem acarretar sobre o ciclo de vida destes organismos.(AU)

The herbicides are among the most used chemical inputs in the agriculture and present a great toxicological action for the plants. Among the existing herbicides, glyphosate and its commercial formulation Roundup® are the most used due to their effectiveness in control of weeds. However, studies suggest that these herbicides can cause disturbances to aquatic organisms, mainly the Roundup®, that besides active glyphosate, it presents in the composition components surfactants that would increase its toxicological potential for the alive beings. Therefore, the aim of this study is to compare the mutagenic potential and gonadal development of the active principle glyphosate and its formulation Roundup® in fish Danio rerio. Thus, adult copies of D. rerio stayed in aquariums exposed to a concentration of 65 µg / L of each herbicide. Micronucleus counts were performed and the Gonadossomatic index (GSI) was calculated and the stages of gonadal maturation were verified. The results demonstrated that the fish exposed to the herbicides, presented significant increases in the micronucleus frequency, as well as in GSI and larger occurrence of ovaries with stages in maturation and mature. There were no significant differences in herbicide comparison, except an increase in the frequency of mature ovaries in the exposed females to glyphosate. It was observed that even in small concentrations, the herbicides could presented harmful effects for the fish D. rerio, could have caused clastogenic effects in the erythrocytes, as well as, reproductive disturbances, increasing the concern about the impacts that these herbicides can have on the life cycle of these organisms.(AU)

Análisis de genotoxicidad en eritrocitos de tortugas (Phrynops hilarii) de sitios antropizados y naturales de Entre Ríos, Argentina / Analysis of genotoxicity in erithrocytes of turtles (Phrynops hilarii) from anthropized and natural sites of Entre Ríos, Argentina

El test de micronúcleos (MN) es un biomarcador de genotoxicidad no destructivo que permite detectar daño cromosómico y otras alteraciones nucleares (AN). Phrynops hilarii es un quelonio de agua dulce que habita regiones del centro-norte de Argentina. El objetivo principal fue determinar la presencia de MN y otras AN en eritrocitos de poblaciones naturales de P. hilarii comparando sus frecuencias entre tres sitios, dos antropizados y uno de control (ciudades de Diamante y Paraná) de Entre Ríos, Argentina, durante el periodo 2015-2016. Dieciocho individuos (seis por sitio de muestreo) fueron evaluados en los sitios: 1- PD: Parque Nacional Pre-Delta (control), 2- AG: Salto Ander Egg (agroecosistema) y 3- SU: Caleta Club Náutico (sistema urbano). Se extrajo sangre de la vena femoral. Las muestras se tiñeron con el método May Grünwald-Giemsa y se observaron bajo un microscopio con el objetivo de inmersión. Las frecuencias de micronúcleos (FMN) y alteraciones nucleares (FAN) se determinaron cada 1000 eritrocitos observados. Se encontró diferencia significativa (p<0,05) entre el sitio PD y los otros sitios (AG y SU), tanto para FMN (p=0,0021) como para FAN (p=0,0011). Los valores de las frecuencias más altos correspondieron al sitio AG (FMN: 3,33±0,62; FAN: 4,67±0,56). Finalmente, el biomonitoreo con P. hilarii fue útil, por lo que podría considerarse como especie bioindicadora para evaluar la calidad de los ambientes de Argentina.

The micronucleus test (MN) is a biomarker of non-destructive genotoxicity that allows chromosomal damage and other nuclear alterations (NA) to be detected. Phrynops hilarii is a freshwater chelonium that inhabits regions of central-northern Argentina. The main objective was to determine the presence of MN and other NA in erythrocytes of natural populations of P. hilarii comparing their frequencies between three sites, two anthropized and one of control (cities of Diamante and Paraná) of Entre Ríos, Argentina, during the period 2015-2016. Eighteen individuals (six per sampling site) were evaluated at the sites: 1- PD: Pre-Delta National Park (control), 2- AG: Salto Ander Egg (agroecosystem) and 3- SU: Caleta Club Náutico (urban system). Blood was obtained from the femoral vein. The samples were stained with the May Grünwald-Giemsa method and observed under a microscope with an immersion objective. Micronucleus (MNF) and nuclear alterations (NAF) frequencies were determined every 1000 erythrocytes observed. A significant difference (p<0.05) was found between the PD site and the other sites (AG and SU), both for MNF (p=0.0021) and for NAF (p=0.0011). The highest frequency values corresponded to the AG site (MNF: 3.33 ± 0.62; NAF: 4.67 ± 0.56). Finally, biomonitoring with P. hilarii was useful, so it could be considered as a bioindicator species to assess the quality of Argentina's environments.

Evaluación de riesgo de cáncer en personas expuestas ocupacionalmente a solventes orgánicos / Cancer risk evaluation in individuals occupationally exposed to organic solvents

RESUMEN Objetivo Evaluar la frecuencia de micronúcleos (MN) e influencia de los polimorfismos en los genes del metabolismo GSTM1 y GSTT1 como biomarcadores de riesgo de cáncer en pintores de carros (n=152) con respecto a individuos no expuestos (n=152). Métodos Estudio Epidemiológico Molecular, tipo Corte Transversal analítico, interacción gen-ambiente. La evaluación de MNs y polimorfismos genéticos se determinó con pruebas moleculares en linfocitos de los individuos objeto de estudio. Resultados Se determinó que la frecuencia de MNs es 1.6 más alta en el grupo expuesto con relación al grupo referente (1.39±0.92 versus 0,87±0.78, p<0,0001). No se determinó un incremento en la frecuencia de MNs asociado a los polimorfismos en GSTM1 y GSTT1. Conclusiones El incremento de MNs en pintores de carros sirve para alertar al incremento de riesgo de cáncer en esta población expuesta a solventes orgánicos. Estos resultados pueden servir en Programas de Vigilancia Epidemiológica Ocupacional, como estrategia de prevención y en otros países con un amplio sector informal de individuos expuestos a estos químicos para reducir el riesgo de cáncer.(AU)

ABSTRACT Objective To evaluate the frequency of micronuclei (MNs) and influence of GSTM1 and GSTT1 gene polymorphisms as biomarkers of cancer risk in car painters (n=152) compared to unexposed individuals (n=152). Methods Molecular epidemiology study, cross-sectional analysis of gen and environment interaction. The evaluation of MN and genetic polymorphisms was determined by molecular tests in lymphocytes from subjects involved in the study. Results It was determined that the frequency of MNs is 1.6 higher in the exposed group compared to the reference group (1.39 ± 0.92 versus 0.87 ± 0.78, p<0.0001). There was no increase in the frequency of MNs associated with the polymorphisms in GSTM1 and GSTT1. Conclusions The increase of MNs in car painters serves to alert the increased risk of cancer in this population exposed to organic solvents. These results can be used in Occupational Epidemiological Surveillance Programs, as a prevention strategy and policies to regulate and control the use of solvents at a national level and in other countries with a large informal sector of individuals exposed to these chemicals to reduce the risk of cancer.(AU)

Teste de micronúcleo para detecção de instabilidade genômica em lesão cervical por papilomavírus humano / Prueba de micronúcleo para detectar inestabilidad genómica en lesión cervical por virus del papiloma humano / Micronucleus test to detect genomic instability in cervical lesion by human papillomavirus

Objetivo: analisar a produção científica acerca do teste de micronúcleo como instrumento para detecção de instabilidade genômica e dos fatores de risco para lesão intraepitelial cervical em pacientes com papilomavírus humano. Método: revisão integrativa de publicações dos últimos 10 anos, realizada no período de agosto de 2017 a junho de 2018, através da Medical Literature Analysis and Retrieval System, Literatura Latino-americana e do Caribe em Ciências da Saúde e PubMed Central. Resultados: quatro artigos foram analisados em que o teste de micronúcleo foi utilizado para detectar instabilidade genômica e risco de lesão intraepitelial cervical e seis artigos como biomarcador em diferentes estágios pré-neoplásicos, neoplásicos em lesões intraepiteliais e fatores de risco para o câncer cervical. Conclusões: o teste de micronúcleo é um método simples, rápido, barato e importante para detectar instabilidade genômica em células intraepiteliais cervicais que apresentam lesão sugestiva para o câncer de colo uterino.(AU)

Objective: to analyze the scientific production about the micronucleus test as an instrument for detecting genomic instability and risk factors for cervical intraepithelial injury in patients with human papillomavirus. Method: integrative review of publications from the last 10 years, carried out from August 2017 to June 2018, through Medical Literature Analysis and Retrieval System, Latin American and Caribbean Literature in Health Sciences and PubMed Central. Results: four articles were analyzed in which the micronucleus test was used to detect genomic instability and risk of cervical intraepithelial injury and in six articles as a biomarker in different pre-neoplastic stages, neoplastic in intraepithelial injuries and risk factors for cervical cancer. Conclusions: the micronucleus test is a simple, fast, inexpensive and important method to detect genomic instability in cervical intraepithelial cells that present lesions suggestive of cervical cancer.(AU)

Objetivo: analizar la producción científica sobre la prueba de micronúcleos como instrumento para detectar la inestabilidad genómica y los factores de riesgo de lesión intraepitelial cervical en pacientes con virus del papiloma humano. Método: revisión integradora de publicaciones de los últimos 10 años, realizada desde agosto de 2017 hasta junio de 2018, a través de la Medical Literature Analysis and Retrieval System, Literatura Latinoamericana y del Caribe en Ciencias de la Salud y PubMed Central. Resultados: se analizaron cuatro artículos en los que se utilizó la prueba de micronúcleos para detectar la inestabilidad genómica y el riesgo de lesión intraepitelial cervical y en seis artículos como biomarcador en diferentes etapas preneoplásicas, neoplásico en lesiones intraepiteliales y factores de riesgo de cáncer cervical. Conclusiones: la prueba de micronúcleos es un método simple, rápido, económico e importante para detectar la inestabilidad genómica en células intraepiteliales cervicales que presentan lesiones sugestivas de cáncer cervical.(AU)

The correlation between micronuclei count and smoking behavior: a hospital-based study / Correlación entre recuento de micronúcleos y hábito tabáquico: un estudio hospitalario

Background: Micronucleus is a microscopically visible cyto-plasmic chromatin mass in the extranuclear vicinity, originating from aberrant mitosis, which consists of eccentric chromosomes that have failed to reach spindle poles during mitosis. The present study was designed to evaluate and compare cytogenetic changes in the buccal mucosa of smokers and non-smokers based on the occurrence of micronuclei. The study aimed to determine the correlation between the micronuclei count and the frequency and duration of smoking habit. Materials and Methods: Two groups (smokers and non-smokers) of 34 individuals each were examined. Cytological buccal smears were taken from participants using a moistened wooden spatula and stained with standard Papanicolaou stain. Presence of micronuclei was assessed at 40X magnification using a light microscope and a count per 500 cells was determined. The results of the study were analyzed statistically using Mann-Whitney U test, Spearman's rank correlation coefficient and Student t-test. Result: Smears from smokers showed a significant increase in the total number of micronuclei per 500 cell count compared to non-smokers. There was a strong positive correlation between the occurrence of micronuclei and the frequency and duration of smoking. A age-related increase in older age groups was also observed. Conclusion: The study reveals a strong positive correlation between the occurrence of micronuclei and the frequency and duration of smoking. This observation is vital in the utilization of the micronuclei detection in smears as a prognostic, educational and interventional tool in the management of patients with smoking habits.

Antecedentes: El micronúcleo es una masa de cromatina citoplasmática microscópicamente visible en el área extranuclear, que se origina a partir de la mitosis aberrante, y que consiste en cromosomas excéntricos que no han podido alcanzar los polos del huso durante la mitosis. El presente estudio fue diseñado para evaluar y comparar los cambios citogenéticos en la mucosa bucal de fumadores y no fumadores en función de la aparición de micronúcleos. El estudio tuvo como objetivo determinar la correlación entre el recuento de micronúcleos y la frecuencia y duración del hábito de fumar. Materiales and Métodos: Se examinaron dos grupos (fumadores y no fumadores) de 34 individuos cada uno. Se tomaron frotis bucales citológicos de todos los participantes con una espátula de madera humedecida y se tiñeron con la tinción estándar de Papanicolaou. La presencia de micronúcleos se evaluó al microscopio óptico con un aumento de 40X y se determinó un recuento por 500 células. Los resultados del estudio se analizaron estadísticamente utilizando la prueba U de Mann-Whitney, el coeficiente de correlación de rango de Spearman y la prueba t de Student. Resultados: Los frotis de fumadores mostraron un aumento significativo en el número total de micronúcleos por 500 células en comparación con los no fumadores. Hubo una fuerte correlación positiva entre la aparición de micronúcleos y la frecuencia y duración del tabaquismo. También se observó un aumento relacionado con la edad en los grupos de mayor edad. Conclusión: el estudio revela una fuerte correlación positiva entre la aparición de micronúcleos y la frecuencia y duración del tabaquismo. Esta observación es vital en la utilización de la detección de micronúcleos en frotis como una herramienta pronostica, educativa e intervencionista en el manejo de pacientes con hábitos de fumar.

Biomarkers of susceptibility and effect in car painters exposed to organic solvents / Biomarcadores de susceptibilidad y efecto en pintores de carros expuestos a solventes orgánicos

Abstract Introduction: Car painters are routinely exposed to organic solvents classified as carcinogenic and mutagenic substances. Objective: To characterize the population susceptibility and evaluate the genotoxic effects of exposure to organic solvents. Methods: A cross-sectional study comparing a group of car painters exposed to organic solvents with a non-exposed group. CYP2E1 polymorphisms and the presence of micronuclei in lymphocytes were determined. Results: One hundred twenty-two workers participated in the study: 62 who worked in car paint shops and were exposed to solvents, and 60 who were not exposed. There were statistically significant differences between the two groups regarding micronucleated cells and nucleoplasmic bridges frequencies (p=0.042 and p=0.046, respectively; exact likelihood ratio). Significant differences were found at the interaction between the CYP2E1 genotype c1c1 and occupational exposure to solvents, with higher frequencies of micronuclei (p= 0.013) and micronucleated cells (p= 0.015). However, when the frequencies of micronuclei, micronucleated cells and nucleoplasmic bridges in the exposure group were compared between the c1c1 and c2c2/c1c2 allele groups of the CYP2E1 polymorphism, statistically significant differences were found. Conclusions: This study confirms that when workers with CYP2E1 polymorphisms, specifically the c1c1 genotype, are exposed to organic solvents, they are more likely to have somatic cell mutations, a condition associated with increased susceptibility to diseases such as cancer

Resumen Introducción: Los pintores de vehículos automotores están rutinariamente expuestos a agentes como los solventes orgánicos, capaces de producir efectos mutágenos y carcinógenos. Objetivo: Caracterizar la susceptibilidad poblacional y evaluar los efectos genotóxicos debidos a la exposición a solventes orgánicos. Métodos: Estudio de corte transversal que comparó a un grupo de pintores de carros expuestos a solven tes orgánicos con un grupo de personas no expuestas. Fueron determinados tanto los polimorfismos de CYP2E1 como la presencia de micronúcleos en linfocitos. Resultados: Participaron 122 personas, 62 trabajadores de talleres de pintura de autos expuestos a solventes y 60 personas no expuestas. Con relación al cuestionario Q 16, 32% de los expuestos refirieron síntomas sugestivos de neurotoxicidad. Las frecuencias de células micronucleadas y de puentes nucleoplásmicos fueron significativamente mayores en los expuestos que en los no expuestos: p= 0.042 y p= 0.046, respectivamente, Razón de verosimilitud exacta). Fueron halladas diferencias significativas en la interacción de CYP2E1 (c1c1) y la exposición ocupacional a solventes, con mayores frecuencias de micronúcleos (p= 0.013) y de células micronucleadas (p= 0.015). Conclusiones: Este estudio reafirma que los trabajadores expuestos a solventes orgánicos con polimorfismos de CYP2E1, específicamente con genotipo c1c1, tienen mayor probabilidad de presentar mutaciones en las células somáticas, condición asociada con una mayor susceptibilidad a enfermedades como el cáncer

Actividad antimutagénica e identificación de compuestos antioxidantes en la planta Poincianella bracteosa (Fabaceae)

Introducción: Poincianella bracteosa (Tul.) L.P. Queiroz. (Fabaceae), conocida como catingueira, es tradicionalmente utilizada en la medicina para tratar diarrea, hepatitis y anemia. Sin embargo, no hay estudios sobre los efectos tóxico genéticos de la P. bracteosa. Objetivo: En el presente estudio se tuvo como objetivo investigar el perfil fitoquímico y el potencial mutagénico y antimutagénico del extracto acuoso de la cáscara de P. bracteosa en Allium cepa y Mus musculus. Métodos: El extracto de la cáscara fue diluido en agua destilada para fornecer las cuatro concentraciones (2, 4, 8 y 16 mg/ml) utilizadas en el bioensayo A. cepa y las tres dosis (10, 20 y 40 mg / Kg) fueron administradas a los ratones (5 animales por grupo). El perfil fito-químico fue realizado por el test colorimétrico para identificar los principales metabólitos secundarios en el extracto de la cáscara. Tras el tratamiento, 5 000 células meristemáticas fueron analizadas para determinar el índice mitótico, el promedio de alteraciones cromosómicas y el porcentaje de reducción de daños. Para ratones, tras 24, 48 y 72 h, la sangre de la cola de cada animal fue recolectado para la preparación de dos láminas por animal. Para cada animal, 2 000 eritrocitos normocromáticos por ratón fueron evaluados para establecer el número de micronúcleos y el efecto protector. Se analizaron los dados por el test de Kruskal-Wallis (P < 0.05). El estudio fito-químico del extracto detectó azúcares reductores y taninos. Resultados: Ninguna de las concentraciones del extracto fue citotóxica y en todos los tratamientos (pre, simultáneo y después) fue observado el efecto citoprotetor en A. cepa. El promedio total de las alteraciones cromosómicas en todas las concentraciones apuntó actividad no mutagénica de la cáscara. El porcentaje de reducción del daño fue observada en los tratamientos pre (de 77.6 al 90.5 %), simultáneo (del 95.6 al 114.7 %) y tras (de 84.8 al 117.7 %). En los ratones, ninguna de las dosis del extracto presentó efecto mutagénico y el porcentaje de reducción del daño osciló de -21.2 al 78.6 % (pre); de 27.5 al 101.3 % (simultánea) y de 85.5 al 120.6 % (tras-tratamiento). Probablemente, los fito-químicos presentes en el extracto no interfirieron en el ciclo celular (A. cepa), tampoco causaron daños al DNA (A. cepa y ratones) y presentaron efecto protector en las dos especies estudiadas. Los datos observados apuntan la importancia del extracto de la cáscara de P. bracteosa para inhibición del daño y quimio prevención. Sin embargo, más estudios deben ser realizados para garantizar su efecto protector sobre el material genético.

Introduction: Poincianella bracteosa (Tul.) L.P. Queiroz. (Fabaceae), known as catingueira, is traditionally used in medicine to treat diarrhea, hepatitis and anemia. However, there are no studies on their toxicogenetic effects. Objective: The present study aimed to investigate the phytochemical profile as well as the mutagenic and antimutagenic potential of P. bracteosa aqueous bark extract in Allium cepa and Mus musculus. Methods: The extract from barks was diluted in distilled water to yield the four concentrations (2, 4, 8 and 16 mg/ml) used in the A. cepa bioassay and the three doses (10, 20 and 40 mg/Kg) administered to the mice (five animals per group). The phytochemical profile was performed by the colorimetric test to identify the main secondary metabolites in the bark extract. After treatment, five-thousand meristematic cells were analyzed to determine the mitotic index, the mean number of chromosome alterations and the percentage of damage reduction. For mice, after 24, 48 and 72 h, tail blood was collected from each animal for the preparation of two slides per animal. For each animal, 2 000 normochromatic erythrocytes per mice were evaluated to establish the number of micronuclei and the protective effect. Data were analyzed by Kruskal-Wallis test (P < 0.05). Results: The phytochemical analysis of the extract detected reducing sugars and tannins. None of the concentrations of extract was cytotoxic and the cytoprotective effect was observed in A. cepa for all treatments (pre-, simultaneous and post-). The total mean of chromosome alterations in all concentrations indicated a non-mutagenic activity of the bark. The percentage of damage reduction was observed in the pre- (77.6 to 90.5 %), simultaneous (95.6 to 114.7 %) and post- (84.8 to 117.7 %) treatments. In mice, none of the dosages of extract presented mutagenic effect and the percentage of damage reduction varied from -21.16 to 78.63 % (pre-); from 27.51 to 101.28 % (simultaneous) and from 85.47 to 120.63 % (post-treatment). Conclusions: Probably, the phytochemicals in the extract did not interfere with the cell cycle (A. cepa) nor caused damage to the DNA (A. cepa and mice), and exhibited protective effect in both studied species. The observed data indicate the importance of P. bracteosa bark extract for the inhibition of damage and chemoprevention. However, more studies should be carried out to ensure its protective effect on the genetic material.

Comparative evaluation of micronuclei in saudi smokers and non-smokers without any visible oral lesions: a pilot study / Evaluación comparativa de micronúcleos en fumadores y no fumadores sauditas sin lesiones orales visibles: un estudio piloto

Objectives: A systematic review was conducted to evaluate effectiveness and safety of beta carotenes for the treatment of oral leukoplakia regarding clinical resolution and prevention of malignant transformation. Material and Methods: The systematic search was conducted in three electronic databases and the study's selection was performed according to pre-set eligibility criteria. Four studies evaluating the efficacy of beta carotenes in oral leukoplakia compared to placebo were included in the review; three of which were assigned for quantitative analysis. Data were extracted, tabulated, quality assessed and statistically analyzed. Results: The meta-analysis revealed that when comparing clinical resolution the beta carotene group favored was favored compared to placebo, with statistically significant difference. However, a meta-analysis comparing beta carotene and placebo groups regarding malignant transformation as a primary outcome failed to show any significant benefit. Furthermore, results showed evidence of beta carotene safety. Conclusion: the overall quality of evidence about efficacy of beta carotene in oral leukoplakia treatment was not high. However, given the obvious safety of this agent, data suggests it could have a promising effect in clinical improvement of oral leukoplakia lesions. However, no evidence supporting its benefits in reducing risk of malignant transformation in these lesions was found. Therefore, further long term, well designed randomized clinical trials are highly recommended.

Introducción: el cáncer oral es un problema grave con alta mortalidad y morbilidad, a pesar de la disponibilidad de los mejores tratamientos. Uno de los factores más importantes para una mortalidad tan alta es su diagnóstico tardío. La mejor manera de enfrentar un problema de este tipo es evitar su aparición creando conciencia entre la población y tenendo un diagnóstico más temprano. El cáncer oral es una enfermedad multifactorial, donde el daño genómico tiene un papel. Se ha demostrado que los micronúcleos (MNi) son un biomarcador importante y en este estudio se utilizó como una herramienta para crear conciencia sobre el riesgo de cáncer oral. Objetivo: evaluar y comparar la frecuencia de MNi en fumadores sin ninguna lesión oral visible (Grupo I) y no fumadores sanos (Grupo II). Materiales y métodos: se obtuvieron citoestimuladores de fumadores sauditas (n = 15, Grupo I) sin ninguna lesión oral visible y no fumadores sanos (n = 15, control, Grupo II) y se tiñeron con hemotoxilina y eosina para evaluar la frecuencia de MNi y las observaciones fueron sometidas a análisis estadístico utilizando la prueba t de Student. Resultados: La frecuencia media de MNi en el Grupo I fue significativamente mayor (p<0.05) que en el Grupo II. El estudio ayuda a educar, motivar y crear conciencia, alentando así a los pacientes a dejar de fumar, y evitando así el cáncer oral antes de su inicio.

Genotoxic effects of mercury chloride on the Neotropical fish Andinoacara rivulatus (Cichlidae: Cichlasomatini)

Understanding the effects of heavy metals in aquatic ecosystems is of significant importance due to their potential to bioaccumulate at various trophic levels and induce damage in DNA. Mercury is considered one of the most dangerous heavy metals, causing chromosomal breakage (clastogenic event) or spindle dysfunction (aneugenic event), that can lead to the formation of encapsulated chromatin into a separate smaller nucleus, generally referred to as a micronucleus. We evaluated the sensitivity of the micronucleus test in the neotropical cichlid Andinoacara rivulatus (Günther 1860). The fish were divided into four groups of 16 individuals, and each group was placed in separate aquaria (140 L) provided with filtered water and constant aeration. Fish were exposed to mercury chloride (HgCl2) at doses 0.1, 0.25, and 0.50 mg/kg body weight, administered by intraperitoneal (IP) injection. Fish from the control group were injected with a physiologic solution. The following erythrocyte anomalies were identified: erythrocytes with micronuclei varying to some extent in size and position in the cytoplasm, blebbed nucleus, binucleated cell, nuclei showing a deep invagination toward the center (notched nuclei). Examination of blood smears demonstrated a higher level of micronucleus and notched erythrocytes in fish injected with HgCl2 than in the controls. There were significant differences in the frequency of micronucleated and notched erythrocytes among the groups exposed to mercury. Linear regression analysis revealed a positive relationship between the frequency of micronucleated and notched erythrocytes (P< 0.0001), with a moderately strong correlation coefficient (R= 0.737). We propose that, in addition to the two so far known mechanisms of micronucleus formation (spindle apparatus damage and chromosomal ruptures), chromatin fragmentation in notched nuclei resulting from a combination of the cytotoxic effects of mercury and mechanical stress, may be a third mechanism of micronuclei genesis.

Comprender los efectos de los metales pesados en los ecosistemas acuáticos es de gran importancia debido a su potencial de bioacumulación en los diversos niveles tróficos y de inducir daños en el ADN. El mercurio, considerado uno de los metales pesados más peligrosos, causa fracturas cromosómicas (evento clastogénico) o disfunción del huso mitótico (evento aneugénico), y puede conducir a la formación de fragmentos de cromatina encapsulada en un núcleo separado más pequeño, generalmente denominado micronúcleo. En este trabajo se evalúa la sensibilidad del test de micronúcleos en el cíclido neotropical Andinoacara rivulatus (Günther 1860). Los peces fueron divididos en cuatro grupos de 16 individuos, y cada grupo se colocó en acuarios separados (140 L) provistos de agua filtrada y aireación constante. Los peces fueron expuestos al cloruro de mercurio (HgCl2) en dosis de 0.1, 0.25 y 0.50 mg/kg de peso corporal, administrada por inyección intraperitoneal (IP). Los peces del grupo control fueron inyectados con solución fisiológica. Se identificaron las siguientes anomalías en los eritrocitos: micronúcleos que varían en tamaño y posición en el citoplasma, núcleo con evaginaciones, células binucleadas núcleos con muesca (núcleos con una profunda invaginación hacia el centro). El examen de los frotis de sangre demostró un mayor nivel de eritrocitos micronucleados y con muesca en peces inyectados con HgCl2 que en los controles. Fueron detectadas diferencias significativas en la frecuencia de eritrocitos micronucleados y células con núcleos con muescas entre los grupos expuestos al mercurio. El análisis de regresión lineal reveló una relación positiva entre la frecuencia de eritrocitos micronucleados y con muescas (P< 0.0001), con un coeficiente de correlación moderadamente fuerte (R= 0.737). Se propone que, además de los dos mecanismos hasta ahora conocidos de formación de micronúcleos (daño del huso mitótico y rupturas cromosómicas), la fragmentación de la cromatina en núcleos con muesca probablemente a causa de la combinación de los efectos citotóxicos del mercurio y el estrés mecánico, podría ser un tercer mecanismo de génesis de micronúcleos.

Avaliação dos efeitos genotóxicos da exposição ocupacional em frentistas atuantes em postos de gasolina no município de Santarém, Pará / Genotoxic effects of occupational exposure among gas station attendants in Santarem, Para, Brazil

Introdução: Profissionais frentistas encontram-se em situação de risco tóxico pela exposição constante aos vapores dos combustíveis. O benzeno, presente na gasolina, é considerado cancerígeno e prejudicial à saúde desses trabalhadores Objetivo: Avaliar os efeitos genotóxicos decorrentes da exposição ocupacional em células esfoliativas da mucosa oral de frentistas do município de Santarém, Pará; e determinar a taxa de adesão ao uso de equipamentos de proteção individual por esses colaboradores. Métodos: Um total de 126 frentistas, distribuídos em 6 grupos contendo indivíduos expostos foram comparados ao grupo controle utilizando a técnica do ensaio de micronúcleos em células da mucosa oral coradas com as técnicas de Feulgen/Fast-green. Resultados: Os frentistas apresentaram maior frequência de micronúcleos em relação ao grupo não exposto ao benzeno (p<0,01). Frentistas com hábito etílico apresentaram aumento significativo de micronúcleos (p<0,01), quando comparados aos frentistas abstêmios. Verificou-se que 100% dos profissionais entrevistados não fazem uso dos equipamentos de proteção. Conclusão: Constatou-se um aumento na presença de micronúcleos em células esfoliativas de frentistas em comparação ao grupo controle. Esse aumento é ainda maior quando o frentista ingere frequentemente bebidas alcoólicas.

Background: Gas station attendants are at high risk of poisoning due to continuous exposure to fuel fumes. Benzene, present in gasoline, is considered a carcinogen and harmful to the health of gas station attendants. Objective: To investigate genotoxic effects on exfoliated oral mucosa cells in association with occupational exposure among gas station attendants in Santarem, Para, Brazil, and to establish the rate of adherence to personal protective equipment (PPE). Methods: The results of the micronucleus test performed with oral mucosa cells stained by means of the Feulgen and Fast Green methods were compared between 126 exposed gas station attendants distributed across six groups and controls. Results: The frequency of micronuclei was higher among gas station attendants compared to the group not exposed to benzene (p<0.01). The frequency of micronuclei was significantly higher (p<0.01) among the gas station attendants who reported to drink alcohol compared to non-drinkers. None of the participants (0%) used PPE. Conclusion: The frequency of micronuclei in exfoliated oral mucosa cells was higher among gas station attendants compared to controls; frequency was even higher for the gas station attendants who reported to consume alcohol often

Efeitos citotóxicos do aripiprazol nas linhagens celulares MKN45 e NIH3T3 e efeitos genotóxicos nos linfócitos sanguíneos periféricos humanos / Cytotoxic effects of aripiprazole on mkn45 and nih3t3 cell lines and genotoxic effects on human peripheral blood lymphocytes

ABSTRACT BACKGROUND: Gastric cancer is known as the fourth most common cancer. Current treatments for cancer have damaged the sensitive tissues of the healthy body, and in many cases, cancer will be recurrent. Therefore, need for treatments that are more effective is well felt. Researchers have recently shifted their attention towards antipsychotic dopamine antagonists to treat cancer. The anticancer activities of aripiprazole remain unknown. OBJECTIVE: This study aimed to evaluate the efficacy and safety of aripiprazole on gastric cancer and normal cell lines. METHODS: In this regard, the cytotoxicity and genotoxicity of aripiprazole were investigated in MKN45 and NIH3T3 cell lines by methyl tetrazolium assay and on peripheral blood lymphocytes by micronucleus assay. For this purpose, cells were cultured in 96 wells plate. Stock solutions of aripiprazole and cisplatin were prepared. After cell incubation with different concentrations of aripiprazole (1, 10, 25, 50, 100 and 200 μL), methyl tetrazolium solution was added. For micronucleus assay fresh blood was added to RPMI culture medium 1640 supplemented, and different concentrations of aripiprazole (50, 100 and 200 μL) were added. RESULTS: The finding of present study showed that the IC50 of aripiprazole in the cancer cell line (21.36 μg/mL) was lower than that in the normal cell line (54.17 μg/mL). Moreover, the micronucleus assay showed that the frequency of micronuclei of aripiprazole at concentrations below 200 μM was much less than cisplatin. CONCLUSION: Aripiprazole can be a good cytotoxic compound and good candidate for further studies of cancer therapy.

RESUMO CONTEXTO: O câncer gástrico é conhecido como o quarto câncer mais comum. Os tratamentos atuais para o câncer danificaram os tecidos sensíveis do corpo saudável e, em muitos casos, o cancro será recorrente. Portanto, a necessidade de tratamentos que são mais eficazes é desejada. Recentemente, os pesquisadores mudaram sua atenção para os antagonistas antipsicóticos da dopamina para tratar o câncer. As atividades anticâncer de aripiprazol permanecem desconhecidas. OBJETIVO: Este estudo objetivou avaliar a eficácia e a segurança do aripiprazol no câncer gástrico e nas linhagens celulares normais. MÉTODOS: A este respeito, a citotoxicidade e a genotoxicidade do aripiprazol foram investigadas em linhas celulares MKN45 e NIH3T3 por ensaio de metil tetrazólio e em linfócitos periféricos de sangue por ensaio de micronúcleos. Para este efeito, as células foram cultivadas em 96 placas. As soluções de estoque de aripiprazol e cisplatina foram preparadas. Após incubação celular com diferentes concentrações de aripiprazol (1, 10, 25, 50, 100 e 200 μL), a solução de metil tetrazólio foi adicionada. Para o ensaio do micronúcleo o sangue fresco foi adicionado ao meio de cultura RPMI 1640 suplementado, e as concentrações diferentes de aripiprazole (50, 100 e 200 μL) foram adicionadas. RESULTADOS: O presente estudo mostrou que o IC50 de aripiprazol na linhagem celular cancerosa (21,36 μg/mL) foi menor do que na linha celular normal (54,17 μg/ mL). Além disso, o ensaio de micronúcleos demonstrou que a frequência de micronúcleos de aripiprazol em concentrações inferiores a 200 μM foi muito inferior à cisplatina. CONCLUSÃO: O aripiprazol pode ser um bom composto citotóxico e bom candidato para estudos adicionais da terapia do câncer.

Evaluation of antimutagenic and cytotoxic activity of skin secretion extract of Rhinella marina and Rhaebo guttatus (Anura, Bufonidae) / Avaliação da atividade antimutagênica e citotóxica da secreção cutânea de Rhinella marina e Rhaebo guttatus (Anura, Bufonidae)

The skin secretion from toads of the Bufonidae family has great potential in the search for new active compounds to be used as drug candidates in treating some diseases, among them cancer. In this context, this study aimed to evaluate the cytotoxic and antimutagenic activity of the parotoid gland secretion extracts of Rhinella marina and Rhaebo guttatus, as well as biochemically analyze transaminases and serum creatinine for liver and renal damage, respectively. Cytotoxicity was performed by the colorimetric method based on MTT (3- [4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide) with different concentrations of the extracts in Walker or splenic tumor cell cultures from rats and mice. The micronucleus test was performed with male Swiss mice treated orally with the extracts for 15 days, and then intraperitoneally with N-ethyl-N-nitrosurea (50 mg kg-1). Micronucleated polychromatic erythrocytes (MNPCE) were evaluated in bone marrow. The extracts showed cytotoxic activity in the evaluated cells. There was a significant reduction in the frequency of MNPCE (R. marina = 56% and R. guttatus = 75%, p < 0.001), indicating antimutagenic potential of the extracts. The groups treated only with extract showed an increase in MNPCE frequency, evidencing mutagenic potential. Biochemical analyzes showed no significant difference between treatments. Thus, under our experimental conditions, the extracts of R. marina and R. guttatus skin secretions presented chemopreventive potential for cancer. (AU)

A secreção cutânea de anuros da família Bufonidae tem grande potencial na busca de novos compostos ativos para utilização como fármacos candidatos no tratamento de algumas doenças, entre elas o câncer. Neste contexto, este estudo teve como objetivo avaliar a atividade citotóxica e antimutagênica dos extratos da secreção da glândula parótida de Rhinella marina e Rhaebo guttatus, bem como a análise bioquímica de transaminases e creatinina séricas, para avaliar dano hepático e renal, respectivamente. A avaliação de citotoxicidade foi realizada pelo método colorimétrico baseado no MTT (3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide), com diferentes concentrações dos extratos em culturas de células do Tumor de Walker ou células esplênicas de rato e camundongo. O teste do micronúcleo foi realizado com camundongos Swiss machos que receberam tratamento oral com os extratos durante 15 dias, seguido de tratamento intraperitoneal com N-etil-N-nitrosuréia (50 mg kg-1). A frequência de eritrócitos policromáticos micronucleados (PCEMN) foi determinada em medula óssea. Os extratos apresentaram ação citotóxica nas células avaliadas. Houve uma redução significativa na frequência de PCEMN (R. marina = 56% e R. guttatus = 75%, p < 0,001), observando-se um potencial antimutagênico dos extratos. Os grupos tratados somente com os extratos apresentaram um aumento na frequência de PCEMNs, evidenciando um potencial mutagênico. As análises bioquímicas não apresentaram diferença significativa entre os tratamentos. Assim, nas condições experimentais testadas, as secreções cutâneas de R. marina e R. guttatus apresentaram potencial quimiopreventivo para câncer.(AU)