RESUMO

OBJECTIVES: This systematic review aimed to compare the cytotoxicity of root canal filling materials (RCFMs) assessed using tetrazolium salt-based tests (TSBT), including the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, with those obtained using other cell viability assays. METHODS: A search was performed on PubMed, Scopus, Web of Science and OpenGrey up to March 2019, followed by a manual search. According to the Participants, Exposure, Comparator and Outcomes (PECO) criteria, in vitro studies that evaluated the cytotoxic effect of RCFMss on animal and/or human cells through TSBT and at least one other viability assay were compared. The methodological quality of selected papers was assessed using ToxRTool® and SciRAP® . Data were analysed using Wilcoxon's signed-rank test for paired samples and linear weighting kappa. RESULTS: A total of 230 non-duplicated records were identified. After applying the eligibility criteria, 55 studies were selected for methodological evaluation, seven were selected by manual searching, 22 were excluded for methodological reasons, and 40 were included. A total of 410 comparisons were performed between TSBT and distinct cell viability tests (DCVT). MTT had moderate concordance with DCVT using human cells (n = 138 samples) (P = 0.507; k = 0.4225) and animal cells (n = 122 samples) (P = 0.124; k = 0.5775). XTT had good concordance using human (n = 110 samples) (P = 0.507; k = 0.6336) and animal cells (n = 12 samples) (P = 0.564; k = 0.6604). MTT, XTT, WST and MTS assays showed moderate concordance with DCVT (n = 410 samples) (P = 0.375; k = 0.5138) and complete agreement in 226 samples. DISCUSSION: The included studies had methodological heterogeneity that was minimized by the systematic review methodology. CONCLUSIONS: MTT and XTT do not cause over- or underestimation of cell viability during cytotoxicity screening of root canal filling materials, implying that these assays can be considered reliable for this purpose. Nonetheless, the development of protocols for the cytotoxic screening of these materials on 3D tissue-like cultures aiming to improve their predictability in the clinical scenario is suggested.

Assuntos

Cavidade Pulpar , Materiais Restauradores do Canal Radicular , Animais , Sobrevivência Celular , Humanos , Materiais Restauradores do Canal Radicular/toxicidade , Obturação do Canal Radicular , Sais de Tetrazólio

RESUMO

Reactive oxygen species (ROS) can be generated in mammalian cells via both enzymatic and non-enzymatic mechanisms. In sperm cells, while ROS may function as signalling molecules for some physiological pathways, the oxidative stress arising from the ubiquitous production of these compounds has been implicated in the pathogenesis of male infertility. In vitro studies have undoubtedly shown that spermatozoa are indeed susceptible to free radicals. However, many reports correlating ROS with sperm function impairment are based on an oxidative stress scenario created in vitro, lacking a more concrete observation of the real capacity of sperm in the production of ROS. Furthermore, sample contamination by leukocytes and the drawbacks of many dyes and techniques used to measure ROS also greatly impact the reliability of most studies in this field. Therefore, in addition to a careful scrutiny of the data already available, many aspects of the relationship between ROS and sperm physiopathology are still in need of further controlled and solid experiments before any definitive conclusions are drawn.

RESUMO

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.

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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.

Assuntos

Humanos , Animais , Camundongos , Linfócitos/efeitos dos fármacos , Aripiprazol/toxicidade , Testes para Micronúcleos/métodos , Células NIH 3T3/efeitos dos fármacos , Testes de Mutagenicidade

RESUMO

To mitigate the economic losses provoked by disease outbreaks, shrimp producers employ therapeutic additives. However, important issues such as the toxicity of these products on shrimp are not always considered. In vivo toxicity assays require a lot of time and large economic and physical resources. Here, we describe an in vitro procedure to evaluate the toxicity of functional additives, used in the production of shrimp Penaeus vannamei. This method adapted the cell viability assay based on the reduction of tetrazolium salts (MTT) to primary cell cultures of shrimp hemocytes. •A simple and reliable tool that requires few physical and economic resources to evaluate in short time (6 h) the cytotoxic effect of therapeutic products and additives to be included in shrimp culture•This inexpensive method requires only a modified Hank's balanced salt solution (HBSS) containing Ca2+ and Mg2+ to keep hemocytes metabolically active to successfully carry out the cytotoxicity assay•This toxicity in vitro assay does not require exposure of the shrimp to compounds at toxic concentrations.

RESUMO

El presente estudio evaluó el desempeño de dos sales de tetrazolio, una tradicional: INT y una de nueva generación: XTT, para estimar la densidad de microorganismos degradadores de hidrocarburos (HCs) en suelos empleando la técnica del Número Más Probable (NMP). Se analizaron 96 muestras de suelo provenientes de la Ecorregión Cafetera de Colombia. Los microorganismos fueron recuperados en agar mínimo de sales en atmósfera saturada de HCs y la capacidad degradadora fue confirmada por repiques sucesivos utilizando diesel como fuente de carbono. No se observaron diferencias significativas en los recuentos de microorganismos degradadores obtenidos con las dos sales (t de Student, p < 0,05), pero el XTT permitió mejor visualización de los pozos positivos dada la solubilidad del producto reducido, mientras que el INT produjo precipitación, debido al formazán insoluble generado, dificultando su lectura. Se obtuvo un mayor porcentaje de aislamientos empleando XTT (67%), lo cual podría indicar que el tipo de sal es determinante en la viabilidad de estas bacterias. Adicionalmente, se evaluó el límite de detección celular, las condiciones óptimas de concentración de XTT y el tiempo de incubación necesario para la detección de actividad degradadora utilizando la cepa Acinetobacter sp. El aumento en la concentración de XTT de 0,5 mM a 2 mM y el tiempo de incubación tuvieron un efecto inhibitorio y favorable respectivamente, en la recuperación de células viables, adicionalmente, límite de detección de la técnica fue de 10² UFC/ml.

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The objective of this study was to evaluate the performance of two tetrazolium indicators: a traditional one: INT and a new generation one: XTT, for the estimation of hydrocarbon (HC) degrading microorganism s density using the Most Probable Number Technique (MPN). Ninety six composite soil samples were taken and analyzed from Ecorregión Cafetera Colombiana. Degrading microorganisms were recovered in minimum salt medium with saturated HC atmosphere. Degrading HC capacity of the microorganisms was confirmed by successive subcultures in the same medium using diesel as only carbon source. Counts obtained with the two salts were not significantly different (Student t test, p < 0,05) but XTT allowed an easier visualization of positive wells due to product solubility of the reduce product. A greater percentage of isolates was obtained using XTT (67%), which suggests that salt type is relevant for recovering of these microorganisms. Additionally, cell detection limit, optimal conditions of XTT concentration and incubation times for detection of activity were evaluated. This evaluation was performed by means of microplate format for hydrocarbon degrading microorganisms using Acinetobacter sp. An inhibitory effect was observed in the recovering of cultivable cells when XTT concentrations increased from 0,5 mM to 2 mM. Incubation time favored this recovering. Detection limit of this technique was established at 10² UFC/ml. Production of the XTT-formazan was positively related with initial cell concentration and negatively with incubation time.

RESUMO

Many methods are used to evaluate ischemia reperfusion injury, but the most employed one is the histological study. However, it only demonstrates on mucosal tunic, the index of lesion and morphologic preserved cells, but not the index of viable functional cells, present in the sample. With this purpose, a colorimetric method was used, employing Methyl Thiazolyl Blue (MTT). The experiment was conducted in 30 Wistar male rats, distributed in 3 groups: Group Control (GC), Group ischemia and reperfusion-1 (GIR-1) and Group ischemia and reperfusion-3 (GIR-3), with 10 animals each. The Groups GIR-1 and GIR-3 were submitted to intestinal ischemia for 30 minutes by a false ligature of superior mesenteric artery, and submitted to euthanasia after 1 and 3 days of reperfusion, when material was picked for absorbency and histological procedures. It was observed a smaller proportion of viable cells and a larger degree of mucosal lesion in GIR-3 group (p 0.05), while GC group was the one with the larger proportion of viable cells and smaller degree of the mucosal injury (p 0.05). This way we concluded that MTT is as effective and reliable as the histological study at evaluating alterations produced by intestinal ischemia-reperfusion.

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Vários métodos são utilizados para avaliar e estimar as lesões intestinais de isquemia e reperfusão (IR). Assim, o objetivo do presente trabalho é realizar o estudo comparativo dos aspectos colorimétrico e histológico da lesão intestinal após IR. Para tal, foram utilizados 30 ratos Wistar, machos, pesando entre 310 a 410g, distribuídos em 3 grupos: Grupo Controle (GC), Grupo Isquemia e Reperfusão-1 (GIR-1) e Grupo Isquemia e Reperfusão-3 (GIR-3), com 10 animais cada. Nos grupos GIR-1 e GIR-3 foi realizada isquemia intestinal, por meio de falsa ligadura da artéria mesentérica anterior, durante 30 minutos e após esta a perfusão sangüínea foi restaurada. Estes animais foram submetidos a eutanásia após 1 e 3 dias de reperfusão, respectivamente, sendo colhido material para realização dos estudos colorimétrico, usando o Methyl Thiazolyl Blue (MTT) e histológico pela hematoxilina e eosina. Os resultados obtidos demonstraram uma menor proporção de células viáveis e um maior grau de lesão da túnica mucosa nos animais do grupo GIR-3 em relação ao controle (p 0,05). Desta forma os autores concluem que o estudo colorimétrico, usando o MTT, mostrou-se tão eficaz e confiável quanto o estudo histológico na avaliação das repercussões intestinais produzidas pela IR deste órgão.