Repositório Institucional - Unifesp :: Navegando por Palavras-chave "Comet assay"

Navegando por Palavras-chave "Comet assay"

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Absence of DNA damage in multiple organs (blood, liver, kidney, thyroid gland and urinary bladder) after acute fluoride exposure in rats
(Sage Publications Ltd, 2007-05-01) Leite, Aline de Lima; Santiago, Joel Ferreira; Levy, Flavia Mauad; Maria, Andrea Gutierrez; Fernandes, Mileni da Silva; Salvadori, Daisy Maria Favero; Ribeiro, Daniel Araki [UNIFESP]; Rabelo Buzalaf, Marflia Afonso; Universidade de São Paulo (USP); Univ Estadual Paulista; Universidade Federal de São Paulo (UNIFESP)
Fluoride has been widely used in dentistry as a caries prophylactic agent. However, there has been some speculation that excess fluoride could cause an impact on genome integrity. in the current study, the potential DNA damage associated with exposure to fluoride was assessed in cells of blood, liver, kidney, thyroid gland and urinary bladder by the single cell gel (comet) assay. Male Wistar rats aging 75 days were distributed into seven groups: Groups 1 (control), 2, 3, 4, 5, 6 and 7 received 0 (deionized water), 10, 20, 40, 60, 80 and 100 mgF/Kg body weight from sodium fluoride (NaF), respectively, by gastrogavage. These groups were killed at 2 h after the administration of the fluoride doses. the level of DNA strand breaks did not increase in all organs evaluated and at all doses of NaF tested, as depicted by the mean tail moment. Taken together, our results suggest that oral exposure to NaF did not result in systemic genotoxic effect in multiple organs related to fluoride toxicity. Since DNA damage is an important step in events leading to carcinogenesis, this study represents a relevant contribution to the correct evaluation of the potential health risk associated with chemical exposure.
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Avaliação odontológica e danos em dna nas mucopolissacaridoses i, ii e vi
(Universidade Federal de São Paulo (UNIFESP), 2013-03-27) Guilheiro, Joice Marques [UNIFESP]; D'Almeida, Vânia [UNIFESP]; http://lattes.cnpq.br/7220411418339421; http://lattes.cnpq.br/9906565818359453; Universidade Federal de São Paulo (UNIFESP)
Background: The goal of the study was to investigate through the comet assay in peripheral blood and analyze in cells of oral mucosa through the micronucleus test damages in DNA leads by GAGs accumulation in patients diagnosed with mucopolysaccharidosis I, II or VI. Moreover, anamnesis and a clinical examination in Dentistry were also performed, and the clinical findings in Dentistry were compared with described by literature. Methods: Twelve patients, treated in Centro de Referência de Erros Inatos do Metabolismo (CREIM - UNIFESP), diagnosed with mucopolysaccharidosis I, II or VI and in enzyme replacement therapy treatment were include in the study. The control group consisted of healthy subjects, with the same age and gender to the patients. For the DNA damage, the comet assay and micronucleus test were performed. An anamnesis and clinical examinations were evaluated for oral manifestations in MPS. The comet assay in peripheral blood was used to detect DNA damages and analyze in cells of oral mucosa through micronucleus to morphological analize and detect cell death parameters. An anamnesis and clinical examinations were evaluated for oral manifestations in MPS. Results: The mean of age of diagnosis for MPS II was 55.75±26.98 months, for MPS VI, 45.5±27.87 months and, for MPS I, 26.75±31.42 months. Significant clinical findings were present in MPS VI (5.25±1.5), followed by MPS I (2.25±1.71), and MPS II (1.5±1.91). The treatment time was 25±23.13 months for MPS I, 36.25±24.5 months for MPS II and, 42±28.56 months for MPS I. The genotoxicity values (comet assay) showed high results in MPS patients, comparing to control group (0.7±1.2). The result for MPS I was 4.7±1.4, in MPS II (higher value), 5.3±1.3 and, 3.2±1.4 for MPS VI. Micronucleus test mean values found was 0.2±0.07 for MPS II, 0.02±0.07 for MPS I and 0.07±0.01 for MPS VI. For cell death (pyknosis, karyorrhexis and karyolysis), the MPS VI had the higher score (34.2±13.4), followed by MPS II (23.7±11.3), and MPS I (20.6±8.5). Conclusions:Our results suggest that genotoxicity and cytotoxicity were more evident in mucosa bucal and peripheral blood from MPS patients than control subjects. Concerning the three types of MPS, the oral findings were evident, mainly in MPS VI patients which, in our sample, begun enzyme replacement therapy more lately than the others MPS.
Acesso aberto (Open Access)
Biomonitoramento citogenético em células da mucosa bucal e sangue periférico em pintores de automóveis
(Universidade Federal de São Paulo, 2012-04-10) Silva, Victor Hugo Pereira da [UNIFESP]; Ribeiro, Daniel Araki [UNIFESP]; http://lattes.cnpq.br/9969803499258672; http://lattes.cnpq.br/4534973277501184; Universidade Federal de São Paulo (UNIFESP)
Os pintores de automóveis estão ocupacionalmente expostos a uma gama de substâncias danosas provenientes não somente das tintas automotivas, mas também de solventes orgânicos, hidrocarbonetos aromáticos policíclicos, resinas plásticas e metais. Essa exposição prolongada pode estar relacionada ao aumento da incidência de doenças crônico-degenerativas inclusive o câncer. O objetivo do presente estudo foi avaliar a citotoxicidade e mutagenicidade por meio do teste do micronúcleo em células da mucosa jugal e genotoxicidade a partir do teste do cometa em leucócitos de sangue periférico em pintores de automóveis. Para o teste do micronúcleo, foi utilizado um total de 24 indivíduos expostos e 21 voluntários controle (indivíduos não-expostos). Para o ensaio do cometa, um total de 24 voluntários expostos e 19 voluntários controle foram avaliados. A análise de células bucais revelou que a frequência de micronúcleos em indivíduos expostos foi significativamente maior uma vez comparada ao controle (p<0,05). Porém, a citotoxicidade não foi diferente entre os grupos. O teste do cometa revelou um aumento estatisticamente significativo no momento da cauda dos cometas dos pintores de automóveis quando comparado ao grupo controle (p<0,05). Em suma, tais resultados sugerem que indivíduos ocupacionalmente expostos a tintas automotivas apresentam genotoxicidade e mutagenicidade em células de sangue periférico e mucosa bucal, respectivamente, sendo necessárias ações profiláticas que diminuam a exposição desses profissionais a esses produtos de risco.
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Cytogenetic biomonitoring in mucopolyssacharosis I, II and IV patients treated with enzyme replacement therapy
(Informa Healthcare, 2014-12-01) Guilheiro, Joice Marques [UNIFESP]; Chaves, Marcelo Donizetti [UNIFESP]; Martins, Ana Maria [UNIFESP]; Ribeiro, Daniel Araki [UNIFESP]; D'Almeida, Vania [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
Background and objectives: the aim of this study was to evaluate genotoxicity and mutagenicity in peripheral blood and buccal mucosal cells in mucopolysaccharidosis (MPS) I, II or VI patients.Methods: A total of 12 patients with MPS type I, II and VI attended at the Institute of Genetics and Inborn Errors of Metabolism treated with enzyme replacement therapy (ERT) and 10 healthy control volunteers were included in this study. Mechanically exfoliated cells from cheek mucosa (left and right side) were used to micronucleus test and single cell gel (comet) assay in peripheral blood cells.Results: the results of this study detected the presence of genetic damage in peripheral blood for all individuals with MPS treated with ERT, regardless of type of MPS as depicted by tail moment results. in addition, an increased number of micronucleated cells were found in buccal cells of MPS type II patients. It was also observed an increase of other nuclear alterations closely related to cytotoxicity as depicted by the frequency of pyknosis, karyolysis and karyorrhexis in buccal mucosa cells of MPS VI patients (p<0.05).Conclusion: Taken together, such results demonstrate that metabolic alterations induced by the enzymatic deficiency characteristic of MPS associated with ERT therapy can induce genotoxicity and mutagenicity in peripheral blood and buccal mucosa cells, respectively. This effect appears to be more pronounced to MPS II.
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Cytogenetic biomonitoring of peripheral blood and oral mucosa cells from car painters
(Informa Healthcare, 2012-09-01) Silva, Victor Hugo Pereira da [UNIFESP]; Moura, Carolina Foot Gomes de [UNIFESP]; Spadari-Bratfisch, Regina Celia [UNIFESP]; Ribeiro, Daniel Araki [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
The aim of the present study was to comparatively evaluate genomic damage and cellular death in exfoliated oral mucosa cells and peripheral blood from car painters. A total of 24 car painters and 19 healthy controls (non-exposed individuals) were included in this setting. Individuals had epithelial cells from cheek mucosa (left and right side) mechanically exfoliated, placed in fixative and dropped in clean slides which were checked for the specific nuclear phenotypes. A total of 5 mu L from peripheral blood was collected for the single cell gel (comet) assay. the results pointed out statistically significant differences (p < 0.05) of micronucleated oral mucosa cells from car painters. in addition, DNA damage was detected in peripheral blood cells by single cell gel (comet) assay. Nevertheless, exposure to car paints did not cause increases other nuclear alterations closely related to cytotoxicity such as karrhyorexis, pyknosis and karyolysis in buccal mucosa cells. in summary, the results of the present study suggest that car painters comprise a high risk group since paints can induce genotoxic and mutagenic effects in peripheral blood and oral mucosa cells, respectively.
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Dragon's blood Croton palanostigma induces genotoxic effects in mice
(Elsevier B.V., 2013-05-20) Maistro, Edson Luis; Ganthous, Giulia; Machado, Marina da Silva; Zermiani, Tailyn; Andrade, Sergio Faloni de; Pires Rosa, Paulo Cesar [UNIFESP]; Perazzo, Fabio Ferreira [UNIFESP]; Univ Estadual Paulista UNESP; Univ Vale Itajai UNIVALI; Universidade Federal de São Paulo (UNIFESP)
Ethnopharmacological relevance: Dragon's blood is a dark-red sap produced by species from the genus Croton (Euphorbiaceae), which has been used as a famous traditional medicine since ancient times in many countries, with scarce data about its safe use in humans. in this research, we studied genotoxicity and clastogenicity of Croton palanostigma sap using the comet assay and micronucleus test in cells of mice submitted to acute treatment.Material and methods: HPLC analysis was performed to identify the main components of the sap. the sap was administered by oral gavage at doses of 300 mg/kg, 1000 mg/kg and 2000 mg/kg. for the analysis, the comet assay was performed on the leukocytes and liver cells collected 24 h after treatment, and the micronucleus test (MN) on bone marrow cells. Cytotoxicity was assessed by scoring 200 consecutive polychromatic (PCE) and normochromatic (NCE) erythrocytes (PCE/NCE ratio).Results and conclusion: the alkaloid taspine was the main compound indentified in the crude sap of Croton palanostigma. the results of the genotoxicity assessment show that all sap doses tested produced genotoxic effects in leukocytes and liver cells and also produced clastogenic/aneugenic effects in bone marrow cells of mice at the two higher doses tested. the PCE/NCE ratio indicated no cytotoxicity. the data obtained suggest caution in the use of Croton palanostigma sap by humans considering its risk of carcinogenesis. (C) 2013 Elsevier Ireland Ltd. All rights reserved.
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Effect of diterpenoid kaurenoic acid on genotoxicity and cell cycle progression in gastric cancer cell lines
(Elsevier France-Editions Scientifiques Medicales Elsevier, 2017) dos Santos Cardoso, Plinio Cerqueira; Machado da Rocha, Carlos Alberto; Leal, Mariana Ferreira [UNIFESP]; Bahia, Marcelo de Oliveira; Avila Alcantara, Diego Di Felipe; dos Santos, Raquel Alves; Goncalves, Natalia dos Santos; Ambrosio, Sergio Ricardo; Cavalcanti, Bruno Coelho; Moreira-Nunes, Caroline Aquino; Pessoa, Claudia do O.; Rodriguez Burbano, Rommel Mario
The goal of our study was to evaluate the effect of kaurenoic acid, obtained from copaiba oil resin, in gastric cancer (GC) and a normal mucosa of stomach (MNP01) cell lines. The compound was tested at concentrations of 2.5, 5, 10, 30 and 60 mu g/mL. Comet and micronucleus assays were used to access its potential genotoxicity in vitro. Moreover, we evaluated the effect of kaurenoic acid in cell cycle progression and in the transcription of genes involved in the control of the cell cycle: MYC, CCND1, BCL2, CASP3, ATM, CHK2 and TP53. Kaurenoic acid induced an increase on cell DNA damage or micronucleus frequencies on GC cell lines in a dose-dependent manner. The GC and MNP01 cell lines entering DNA synthesis and mitosis decreased significantly with kaurenoic acid treatment, and had an increased growth phase compared with non-treated cells. The treatment induced apoptosis (or necrosis) even at a concentration of 2.5 mu g/mL in relation to non-treated cells. GC cell lines presented reduced MYC, CCND1, BCL2 and CASP3 transcription while ATM, CHK2 and TP53 increased in transcription in relation to nontreated cells, especially at a concentration above 10 mu g/mL. The gene transcription in the MNP01 (nontreated non-cancer cell line) was designated as a calibrator for all the GC cell lines. In conclusion, our results showed that kaurenoic acid obtained from Copaifera induces DNA damage and increases the micronuclei frequency in a dose-dependent manner in GC cells, with a significant genotoxicity observed above the concentration of 5 mu g/mL. Moreover, this compound seems to be able to induce cell cycle arrest and apoptosis in GC cells. (C) 2017 Elsevier Masson SAS. All rights reserved.
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Evaluation of the genotoxicity of Euterpe oleraceae Mart. (Arecaceae) fruit oil (acai), in mammalian cells in vivo
(Pergamon-Elsevier Science Ltd, 2016) Marques, E. S.; Froder, J. G.; Carvalho, J. C. T.; Rosa, P. C. P.; Perazzo, F. F. [UNIFESP]; Maistro, E. L.
E. oleracea is a tropical plant from the Amazon region, with its fruit used for food, and traditionally, as an antioxidant, anti-inflammatory, hypocholesterolemic, for atherosclerotic disease, and has anticancer properties. The oil of the fruit has antidiarrheic, anti-inflammatory and antinociceptive activities, but without genotoxicity evaluation. Therefore, the aim of this study was to evaluate the genotoxic potential of E. oleracea fruit oil (EOO), in rat cells. Male Wistar rats were treated with EOO by gavage at doses of 30, 100 and 300 mg/kg, for 14 days, within a 24 h interval. The DNA damage in the leukocytes, liver, bone marrow and testicular cells, was assessed by the comet assay, and the clastogenic/aneugenic effects in the bone marrow cells, by the micronucleus test. Our phytochemicals characterization of the EOO showed the presence of vanillic, palmitic, gamma-linolenic, linoleic, oleic, cinnamic, caffeic, protocatechuic, ferulic, syringic acids, and flavonoids quercetin and kaempferol rutinoside as the main constituents. Both cytogenetic tests performed showed that EOO presented no significant genotoxic effects in the analyzed cells, at the three tested doses. These results indicate that, under our experimental conditions, E. oleracea fruit oil did not reveal genetic toxicity in rat cells. (C) 2016 Published by Elsevier Ltd.
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First cytotoxic, genotoxic, and antigenotoxic assessment of Euterpe oleracea fruit oil (acai) in cultured human cells
(Funpec-Editora, 2017) Marques, E. S.; Tsuboy, M. S. F.; Carvalho, J. C. T.; Rosa, P. C. P.; Perazzo, F. F. [UNIFESP]; Gaivao, I. O. M.; Maistro, E. L.
Euterpe oleracea Mart., popularly known as "acai", is a tropical fruit from the Amazon region where it has considerable economic importance. Acai has been used as food and for several medicinal purposes. Despite the widespread use of this fruit, there is a lack of data regarding the safety of using this fruit oil exclusively. Therefore, we evaluated the in vitro cytotoxic, genotoxic, and antigenotoxic effects of E. oleracea fruit oil (EOO) in cultured human lymphocytes (non-metabolizing cells) and HepG2 cell line (human hepatoma) (metabolizing cells) by using MTT, comet, and micronucleus assays. A wide range of EOO concentrations was tested with a preliminary MTT assay, which allowed selecting five concentrations for comet and micronucleus assays: 2.5, 10, 100, 500, and 1000 mu g/mL. The results showed that none of the EOO tested concentrations presented cytotoxic effects. The genotoxic assessment revealed an absence of significant DNA and chromosome damage in human lymphocytes and HepG2 cells but did not show chemoprotection against the DNA damage induced by methyl methanesulfonate and benzo[a] pyrene, used as DNA-damaging agents.
Acesso aberto (Open Access)
O flúor pode ser considerado um agente genotóxico in vivo? Uma revisão sistemática
(Universidade Federal de São Paulo, 2023-09-22) Drummond, Giovana Wagner Branda [UNIFESP]; Ribeiro, Daniel Araki [UNIFESP]; http://lattes.cnpq.br/9969803499258672; Universidade Federal de São Paulo (UNIFESP)
O objetivo deste estudo foi realizar uma revisão sistemática (RS) para investigar a literatura científica sobre os efeitos genotóxicos da exposição ao flúor (EF). As diretrizes do PRISMA-P foram utilizadas nesse cenário. A ferramenta PICOS (Participantes, Intervenção, Comparação, Desfecho e Desenho do estudo) adotou responder à seguinte questão: "O flúor pode ser considerado um agente químico genotóxico in vivo?" As bases de dados utilizadas para este estudo foi PubMed/Medline, SCOPUS e Web of Science. A qualidade dos estudos incluídos foi avaliada por meio do EPHP (Effective Public Health Practice Project). Um total de 20 estudos foram selecionados para avaliar a genotoxicidade induzida pelo flúor. 7 estudos demonstraram resultado positivo enquanto 13 estudos demonstraram resultados negativos. Após a revisão dos vinte estudos, 2 foram classificados como fracos, 4 foram considerados moderados e 14 foram considerados fortes, de acordo com a EPHPP. Dos 20 somente 16 estudos foram incluídos na metanálise devido a classificação como fraco e não descrição adequada de desvio padrão. A metanálise dos estudos de micronúcleos (MN) em fígado e medula óssea não mostrou diferença estatisticamente significativa (p=0,07). Nos estudos de troca de cromátides irmãs (ECS) em linfócitos também não diferiram estatisticamente significativamente (p=0,80). Para o ensaio de cometa (SCGEA), os estudos revelaram diferença estatisticamente significante com F em relação ao controle nos rins (SMD=2.09, 95% CI, 0.74 to 3.45, p<0.001), com Tau2=1,44; Chi2=566,38 e p=0,002, de modo que os estudos selecionados foram considerados heterogêneos e o I² de 87% indicou alta heterogeneidade. Em conjunto, foi estabelecido que a genotoxicidade do flúor é limitada e dose dependente.
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Genotoxic assessment of Rubus imperialis (Rosaceae) extract in vivo and its potential chemoprevention against cyclophosphamide-induced DNA damage
(Elsevier B.V., 2014-05-14) Costa Rodrigues Alves, Ana Beatriz; Santos, Rafaella Souza dos; Calil, Susana de Santana; Niero, Rivaldo; Lopes, Jhonny da Silva; Perazzo, Fabio E. [UNIFESP]; Pires Rosa, Paulo Cesar [UNIFESP]; Andrade, Sergio Faloni; Cechinel-Filho, Valdir; Maistro, Edson Luis; Univ Estadual Paulista; Univ Vale Itajai; Universidade Federal de São Paulo (UNIFESP)
Ethnopharmacological relevance: Rubus imperialis Cham. Schl. (Rosaceae) is frequently used in traditional medicine as hypoglycemic, antinociceptive and antiviral remedy.Materials and methods: Swiss albino mice were distributed in eight groups for acute treatment with Rubus imperialis extract (24 h). the extract doses selected were 50, 250 and 500 mg/kg b.w. administered by gavage alone or plus to CPA (50 mg/kg b.w.) administered by intraperitoneal injection. Control groups were treated in a similar way. Analyses were performed using the comet assay, on leukocytes (collected 4 and 24 h after treatment) and liver (collected 24 h after treatment), and using the micronucleus test (MN) in bone marrow cells. Cytotoxicity was assessed by scoring 200 consecutive polychromatic (PCE) and normochromatic (NCE) erythrocytes (PCE/NCE ratio).Results and conclusion: the main compounds identified in the Rubus imperialis extract were saponins and steroidal compounds, with niga-ichigoside and tormentic acid being the major compounds. Tested doses of Rubus imperialis extract showed no genotoxic effects on leukocytes from peripheral blood or liver cells by the comet assay. However, the MN test showed an increase in the frequency of micronucleated cells at the two higher doses tested, indicating that this extract has clastogenic/aneugenic effects on bone marrow cells at higher doses. On the other hand, for all cells evaluated, the three tested doses of the Rubus imperialis extract promoted inhibition of DNA damage induced by CPA. Despite the chemoprevention observed, the clastogenicity/aneugenicity observed suggested caution about either continuous or high-dose usage of Rubus imperiale aerial parts extract by humans. (C) 2014 Elsevier Ireland Ltd. All rights reserved.
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Genotoxic evaluation of the antimalarial drugs artemisinin and artesunate in human HepG2 cells and effects on CASP3 and SOD1 gene expressions
(Funpec-editora, 2013-01-01) Aquino, Ivani; Tsuboy, Marcela Stefanini Ferreira; Marcarini, Juliana Cristina; Mantovani, Mário Sérgio; Perazzo, Fábio Ferreira [UNIFESP]; Maistro, Edson Luis; Universidade de São Paulo (USP); Univ Estadual Paulista; Universidade Estadual de Londrina (UEL); Universidade Federal de São Paulo (UNIFESP)
The malaria treatment recommended by the World Health Organization involves medicines derived from artemisinin, an active compound extracted from the plant Artemisia annua, and some of its derivatives, such as artesunate. Considering the lack of data regarding the genotoxic effects of these compounds in human cells, the objective of this study was to evaluate the cytotoxicity and genotoxicity, and expressions of the CASP3 and SOD1 genes in a cultured human hepatocellular liver carcinoma cell line (HepG2 cells) treated with artemisinin and artesunate. We tested concentrations of 2.5, 5, 7.5, 10, and 20 mu g/mL of both substances with a resazurin cytotoxicity assay, and the concentrations used in the genotoxicity experiments (2.5, 5, and 10 mu g/mL) and gene expression analysis (5 mu g/mL) were determined. the results of the comet assay in cells treated with artemisinin and artesunate showed a significant dose-dependent increase (P < 0.001) in the number of cells with DNA damage at all concentrations tested. However, the gene expression analysis revealed no significant change in expression of CASP3 or SOD1. Our data showed that although artemisinin and artesunate exhibited genotoxic effects in cultured HepG2 cells, they did not significantly alter expression of the CASP3 and SOD1 genes at the doses tested.
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Genotoxicity assessment of Garcinia achachairu Rusby (Clusiaceae) extract in mammalian cells in vivo
(Elsevier B.V., 2012-07-13) Marques, Eduardo de Souza; Silva, Suellen; Niero, Rivaldo; Andrade, Sérgio Faloni de; Rosa, Paulo César Pires [UNIFESP]; Perazzo, Fábio Ferreira [UNIFESP]; Maistro, Edson Luis; Univ Estadual Paulista; Universidade de São Paulo (USP); Univ Vale Itajai; Universidade Federal de São Paulo (UNIFESP)
Ethnopharmacological relevance: Garcinia achachairu Rusby (Clusiaceae) is popularly known as achachairu, and is used in Bolivian folk medicine for its healing, digestive, and laxative properties, and in the treatment of gastritis, rheumatism and inflammation. Despite its widespread therapeutic use, there is a lack of data regarding its in vivo genotoxic effects. Therefore, in this study, we used the comet assay and the micronucleus test, respectively, to evaluate the possible genotoxic and clastogenic effects of Garcinia achachairu seed extract (GAE) on different cells of mice.Material and methods: the GAE was administered by oral gavage at doses of 500, 1000 and 2000 mg/kg. for the analysis, the comet assay was performed on the leukocytes (collected 4 and 24 h after treatment), liver, bone marrow and testicular cells (collected 24 h after treatment), and the micronucleus test (MN) on bone marrow cells. Cytotoxicity was assessed by scoring 200 consecutive polychromatic (PCE) and normochromatic (NCE) erythrocytes (PCE/NCE ratio).Results and conclusion: the results showed that GAE did not induce significant DNA damage in leukocytes (4 h and 24 h samples), liver, bone marrow and testicular cells (24 h samples). GAE also did not show any significant increase in micronucleated polychromatic erythrocytes (MNPCEs) at the three tested doses. the PCE/NCE ratio indicated no cytotoxicity. Under our experimental conditions, the data obtained suggest that a single oral administration of G. achachairu extract does not cause genotoxicity and clastogenicity in different cells of mice. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
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Genotoxicity of corrosion eluates obtained from endosseous implants
(Lippincott Williams & Wilkins, 2007-03-01) Ribeiro, Daniel Araki [UNIFESP]; Matsumoto, Mariza Akemi; Marques Padovan, Luis Eduardo; Marques, Mariangela Esther Alencar; Salvadori, Daisy Maria Favero; Universidade Federal de São Paulo (UNIFESP); Univ Sagrado Coracao; Univ Estadual Paulista
Purpose: Commercially pure titanium alloys are currently used as metallic biomaterials in implantology. Corrosion phenomena appear to play a decisive role in metallic implant long-term behavior. Thus, the goal of this study was to examine the genotoxic potential of corrosion eluates obtained from dental implants using Chinese ovary hamster cells in vitro by the single-cell gel (comet) assay. This technique detects deoxyribonucleic acid strand breaks in individual cells in alkaline conditions.Materials and Methods: the materials tested included 3 dental implants commercially available. Each of the tested materials was corroded in a solution consisting of equal amounts of acetic acid and sodium chloride (0.1 M) for 1, 3, 7, 14, and 21 days. the Chinese ovary hamster cultures were then exposed to all corrosion eluates obtained from endosseous dental implants for 30 minutes at 37 degrees C.Results: None of the eluates was found to exhibit genotoxicity, regardless of the type of dental implant used.Conclusion: the results suggest that all dental implants tested in this study did not induce deoxyribonucleic acid breakage as depicted by the single-cell gel (comet) assay.
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In vivo evaluation of the genetic toxicity of Rubus niveus Thunb. (Rosaceae) extract and initial screening of its potential chemoprevention against doxorubicin-induced DNA damage
(Elsevier B.V., 2015-04-22) Tolentino, Flora; Arai, Priscila Alves de; Marques, Eduardo de Souza; Petreanu, Marcel; Andrade, Sergio Faloni de; Niero, Rivaldo; Perazzo, Fabio F. [UNIFESP]; Pires Rosa, Paulo Cesar; Maistro, Edson Luis; Univ Estadual Paulista UNESP; Univ Vale Itajai UNIVALI; Universidade Federal de São Paulo (UNIFESP); Universidade Estadual de Campinas (UNICAMP)
Ethnopharmacological relevance: Rubus niveus Thunb. plant belongs to Rosaceae family and have been used traditionally to treat wounds, burns, inflammation, dysentery, diarrhea and for curing excessive bleeding during menstrual cycle. the present study was undertaken to investigate the in vivo genotoxicity of Rubus niveus aerial parts extract and its possible chemoprotection on doxorubicin (DXR)-induced DNA damage. in parallel, the main phytochemicals constituents in the extract were determined.Materials and methods: the animals were exposed to the extract for 24 and 48 h, and the doses selected were 500, 1000 and 2000 mg/kg b.w. administered by gavage alone or prior to DXR (30 mg/kg b.w.) administered by intraperitoneal injection. the endpoints analyzed were DNA damage in bone marrow and peripheral blood cells assessed by the alkaline alkaline (pH > 13) comet assay and bone marrow micronucleus test.Results and conclusion: the results of chemical analysis of the extract showed the presence of tormentic acid, stigmasterol, quercitinglucoronide (miquelianin) and niga-ichigoside F1 as main compounds. Both cytogenetic endpoints analyzed showed that there were no statistically significant differences (p > 0.05) between the negative control and the treated groups with the two higher doses of Rubus niveus extract alone, demonstrating absence of genotoxic and mutagenic effects. Aneugenic/clastogenic effect was observed only at 2000 mg/kg dose. On the other hand, in the both assays and all tested doses were observed a significant reduction of DNA damage and chromosomal aberrations in all groups co-treated with DXR and extract compared to those which received only DXR. These results indicate that Rubus niveus aerial parts extract did not revealed any genotoxic effect, but presented some aneugenic/clastogenic effect at higher dose; and suggest that it could be a potential adjuvant against development of second malignant neoplasms caused by the cancer chemotherapic DXR. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
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Insulin resistance is associated with DNA damage in peripheral blood cells in non-diabetic patients with genotype 1 chronic hepatitis C
(Informa Healthcare, 2013-09-01) Sakae, Patricia Naomi [UNIFESP]; Ihara, Silvia Saiuli Miki [UNIFESP]; Ribeiro, Daniel Araki [UNIFESP]; Carvalho, Luciana de [UNIFESP]; Parise, Edison Roberto [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
Background. in chronic liver diseases of different etiologies, including viral hepatitis, genotoxic effects of oxidative stress have been shown, both in clinical and in experimental conditions, suggesting that this mechanism may contribute to the evolution of the disease. Aim. To evaluate DNA damage in the peripheral blood of untreated non-diabetic patients with chronic hepatitis C and control subjects, and its correlation with demographic, anthropometric, biochemical, and histological parameters in the patient sample. Patients and methods. This study comprised 100 subjects of both genders, 60 of whom were treatment-naive patients with positive serology for genotype 1 hepatitis C. the remaining 40 were blood donors with negative serology for hepatitis who were used as control subjects, and matched by gender, age, weight, and BMI. DNA damage was determined using the comet assay in the total peripheral blood. Results. the DNA damage evaluated by the comet assay revealed higher values in the group of patients with hepatitis compared with that in the control group. the relationships of the comet assay with the studied variables were assessed using multivariate analysis; significant correlations were only identified with insulin (r = 0.343, p = 0.008) and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) (r = 0.331, p = 0.011). Conclusion. Patients with genotype 1 chronic hepatitis C have higher rates of DNA damage, as determined by comet assay and this alteration is correlated with the HOMA index of insulin resistance.
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Intermittent PTH1-34 Causes DNA and Chromosome Breaks in Osteoblastic and Nonosteoblastic Cells
(Springer, 2010-11-01) Alves de Oliveira, Elisangela Claudia [UNIFESP]; Szejnfeld, Vera Lucia [UNIFESP]; Silva, Neusa Pereira da [UNIFESP]; Coelho Andrade, Luis Eduardo [UNIFESP]; Moura Castro, Charlles Heldan de [UNIFESP]; Disciplina Reumatol; Universidade Federal de São Paulo (UNIFESP)
Toxicological studies have demonstrated that intermittent PTH1-34 treatment is associated with an increased incidence of osteosarcoma in Fischer 344 rats. Comet and micronucleus (MN) tests, standard methods to evaluate genotoxic potential of drugs, were used to detect DNA and chromosome breaks, respectively, after PTH1-34 treatment. MC3T3 cells, primary osteoblast calvarial cells, and human osteoblasts were treated with PTH1-34 (50 and 100 nM) for 6 h/day for 21 days to mimic intermittent administration. Genotoxic assays were performed at 6 h and 7, 14, and 21 days. Osteoblasts extracted from bone marrow of mice treated with daily subcutaneous PTH1-34 injections (20 and 40 mu g/kg) for 10 weeks as well as Hep-2, HeLa, and Hep-G2 cells were also tested. We observed a significant increase in DNA lesions and MN prevalence in human and murine osteoblasts treated with PTH1-34 compared to controls (P < 0.01). the effect observed in vitro and confirmed in vivo was time- and dose-dependent. for nonosteoblastic Hep-2 and HeLa cells we observed increased DNA damage and MN prevalence only later in the course of the protocol, after 21 days of treatment (P < 0.01). in Hep-G2 cells intermittent PTH1-34 did not induce DNA damage or chromosome breaks. Our results demonstrated that intermittent PTH increases DNA and chromosome breaks in osteoblasts. This genotoxic effect is attenuated in nonosteoblastic cells, and the ability to induce DNA damage is lost in cells with detoxification properties (HepG2 cells) tested in vitro.
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Lycopene activity against chemically induced DNA damage in Chinese hamster ovary cells
(Elsevier B.V., 2007-08-01) Scolastici, Clarissa; Lima, Rodrigo Otavio Alves de; Barbisan, Luis Fernando; Ferreira, Ana Lucia dos Anjos; Ribeiro, Daniel Araki [UNIFESP]; Salvadori, Daisy Maria Favero; São Paulo State Univ; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
Lycopene is a natural pigment synthesized by plants and microorganisms, and it is mainly found in tomatoes. It is an acyclic isomer of P-carotene and one of the most potent antioxidants. Several studies have demonstrated the ability of lycopene to prevent chemically induced DNA damage; however, the mechanisms involved are still not clear. in the present study, we investigated the antigenotoxic/antimutagenic effects of lycopene in Chinese Hamster Ovary Cells (CHO) treated with hydrogen peroxide, methylmethanesulphonate (MMS), or 4-nitroquinoline-1-oxide (4-NQO). Lycopene (97%), at final concentrations of 10, 25, and 50 M, was tested under three different protocols: before, simultaneously, and after the treatment with the mutagens. Comet and cytokinesis-block micronucleus assays were used to evaluate the level of DNA damage. Data showed that lycopene reduced the frequency of micronucleated cells induced by the three mutagens. However, this chemopreventive activity was dependent on the concentrations and treatment schedules used. Similar results were observed in the comet assay, although some enhancements of primary DNA damage were detected when the carotenoid was administered after the mutagens. in conclusion, our findings confirmed the chemopreventive activity of lycopene, and showed that this effect occurs under different mechanisms. (c) 2007 Elsevier B.V. All rights reserved.
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Mutagenic potential of Cordia ecalyculata alone and in association with Spirulina maxima for their evaluation as candidate anti-obesity drugs
(Funpec-editora, 2014-01-01) Araldi, Rodrigo Pinheiro; Rechiutti, Bruna Mendes; Mendes, Thais Biude [UNIFESP]; Ito, Eliana Tiemi; Souza, Edislaine Barreto; Univ Estadual Paulista; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
Obesity is one of the most important nutritional disorders, and can be currently considered as an epidemic. Although there are few weight reduction drugs available on the market, some new drug candidates have been proposed, including Cordia ecalyculata, a Brazilian plant with anorectic properties, and Spirulina maxima, a cyanobacterium with antioxidant and anti-genotoxic activity. in this study, we evaluated the mutagenic potential of C. ecalyculata at doses of 150, 300, and 500 mg/kg alone and in association with S. maxima at doses of 75, 150, and 250 mg/kg, respectively, through an in vivo micronucleus test, using mice of both sexes, and an in vitro micronucleus test and comet assay, using human peripheral blood. for all tests, cyclophosphamide was used as a positive control. the results showed that treatment of 300 mg/kg C. ecalyculata and the combination treatment of 500 mg/kg C. ecalyculata with 250 mg/kg S. maxima resulted in anorectic effects. the mutagenic tests did not reveal any clastogenic or genotoxic activity for any treatment, indicating that these candidates could be marketed as weight-reduction drugs. Moreover, the drugs contain chemo-preventive substances that can protect against tumorigenesis, which has been associated with obesity.
Acesso aberto (Open Access)
Sildenafil ameliorates oxidative stress and DNA damage in the stenotic kidneys in mice with renovascular hypertension
(Biomed Central Ltd, 2014-02-06) Dias, Ananda T.; Rodrigues, Bianca P.; Porto, Marcella L.; Gava, Agata L.; Balarini, Camille M.; Freitas, Flavia P. S.; Palomino, Zaira [UNIFESP]; Casarini, Dulce Elena [UNIFESP]; Campagnaro, Bianca P.; Pereira, Thiago M. C.; Meyrelles, Silvana S.; Vasquez, Elisardo C.; Univ Fed Espirito Santo; Univ Fed Paraiba; Universidade Federal de São Paulo (UNIFESP); Univ Vila Velha; Fed Inst Educ Sci & Technol IFES
Background: Oxidative stress and DNA damage have been implicated in the pathogenesis of renovascular hypertension induced by renal artery stenosis in the two-kidney, one-clip (2K1C) Goldblatt model. Considering our previous report indicating that the chronic blockade of phosphodiesterase 5 with sildenafil (Viagra (R)) has marked beneficial effects on oxidative stress and DNA damage, we tested the hypothesis that sildenafil could also protect the stenotic kidneys of 2K1C hypertensive mice against oxidative stress and genotoxicity.Methods: the experiments were performed with C57BL6 mice subjected to renovascular hypertension by left renal artery clipping. Two weeks after clipping, the mice were treated with sildenafil (40 mg/kg/ day for 2 weeks, 2K1C-sildenafil group) or the vehicle (2K1C). These mice were compared with control mice not subjected to renal artery clipping (Sham). After hemodynamic measurements, the stenotic kidneys were assessed using flow cytometry to evaluate cell viability and the comet assay to evaluate DNA damage. Measurements of intracellular superoxide anions and hydrogen peroxide levels as well as nitric oxide bioavailability were also obtained.Results: Sildenafil treatment significantly reduced mean arterial pressure (15%), heart rate (8%), intrarenal angiotensin II (50%) and renal atrophy (36%). in addition, it caused a remarkable decrease of reactive oxygen species production. On the other hand, sildenafil increased nitric oxide levels relative to those in the nontreated 2K1C mice. Sildenafil treatment also significantly reduced the high level of kidney DNA damage that is a characteristic of renovascular hypertensive mice.Conclusions: Our data reveal that sildenafil has a protective effect on the stenotic kidneys of 2K1C mice, suggesting a new use of phosphodiesterase 5 inhibitors for protection against the DNA damage observed in the hypoperfused kidneys of individuals with renovascular hypertension. Further translational research is necessary to delineate the mechanisms involved in the prevention of renal stenosis in the clinical setting.

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