Induction of cytotoxicity, oxidative stress and genotoxicity by root filling pastes used in primary teeth.

AIM: To evaluate the cytotoxicity, oxidative stress and genotoxicity in vitro of four iodoform pastes and three calcium hydroxide pastes. METHODOLOGY: Peripheral blood mononuclear cells (PBMCs) and pure calf thymus DNA (dsDNA) were exposed to extracts of the pastes. Cytotoxicity was assessed with the MTT assay. Generation of reactive oxygen species (ROS) was evaluated using a DCFH-DA assay, and lipid peroxidation was evaluated using a TBARS assay. Genotoxicity was evaluated using the alkaline comet assay and Genomodifier capacity assay (GEMO). All tests were performed after 24 h and 72 h of cell exposure, except GEMO. After performing the Kolmogorov-Smirnov test, data were analysed by Kruskal-Wallis and Dunn's post-tests, and anova with Dunnett's post-test, with a significance level established at P < 0.05. RESULTS: The MTT assay revealed that chlorhexidine, Maxitrol and neomycin sulphate + bacitracin pastes decreased cell viability after 24 h (P < 0.05). No group was associated with a significant decreased cell viability or lipid peroxidation after 72 h. Calcium hydroxide pastes increased the cell viability levels at both experimental times (P < 0.05). Lipid peroxidation was observed with the exposure of cells to calcium hydroxide pastes after 24 h (P < 0.05). Exposure to chlorhexidine, Guedes-Pinto and calcium hydroxide pastes resulted in a significant increase in ROS after 24 h (P < 0.05), whereas iodoform pastes and Calen thickened with zinc oxide significantly increased the ROS after 72 h (P < 0.05). The comet assay revealed that exposure of the PBMCs to iodoform pastes did not damage DNA at either period of time (P > 0.05). However, chlorhexidine paste caused DNA damage in dsDNA (P < 0.05). Calcium hydroxide pastes caused DNA damage in both tests (P < 0.05). CONCLUSION: The pastes varied in their ability to induce cytotoxicity, genotoxicity and oxidative stress. In general, Guedes-Pinto, Maxitrol and neomycin sulphate + bacitracin pastes exhibited better biocompatibility in vitro.

Toxicity of irrigating solutions and pharmacological associations used in pulpectomy of primary teeth.

AIM: To evaluate the in vitro toxicity of irrigating solutions and pharmacological associations used in the pulpectomy of primary teeth. METHODOLOGY: The cell viability (MTT), lipid peroxidation (TBARS), alkaline comet assay and GEMO tests were performed to evaluate the cytotoxicity and genotoxicity of solutions: sodium hypochlorite (1% and 2.5%), 2% chlorhexidine, 6% citric acid and 17% EDTA, which were tested, individually and in association, exposing human peripheral blood mononuclear cells (MTT, TBARS and alkaline comet assay), at 24 and 72 h, and dsDNA (GEMO). After performing the Kolmogorov-Smirnov test, data were analysed by anova followed by Dunnett's post hoc test, and Kruskal-Wallis followed by Dunn post hoc test. A significance level was established at P < 0.05. RESULTS: All irrigating solutions and pharmacological associations reduced cell viability at 24 h (P < 0.05). These reductions were maintained after 72 h, except for EDTA and associations of sodium hypochlorite (1% and 2.5%) with EDTA and of chlorhexidine with EDTA. Lipid peroxidation at 24 h was caused by EDTA and by 2.5% sodium hypochlorite with EDTA; it was also caused at 72 h by sodium hypochlorite (1% and 2.5%) and the three associations with citric acid (P < 0.05). All groups caused DNA damage when assessed by the alkaline comet assay, at 24 h and 72 h (P < 0.05). In the GEMO assay, all groups caused dsDNA damage (P < 0.05), except for chlorhexidine with EDTA. CONCLUSION: All groups showed some level of toxicity. Amongst the main solutions, chlorhexidine presented less cytotoxic potential. EDTA was the least cytotoxic of the auxiliary irrigant solutions, and the association of these two solutions showed the lowest toxicity potential amongst all groups.

Hypercholesterolemia and Ecto-enzymes of Purinergic System: Effects of Paullinia cupana.

Hypercholesterolemia is a metabolic disorder characterized by high levels of low-density lipoprotein and blood cholesterol, causing inflammatory lesion. Purinergic signaling modulates the inflammatory and immune responses through adenine nucleotides and nucleoside. Guaraná has hypocholesterolemic and antiinflammatory properties. Considering that there are few studies demonstrating the effects of guaraná powder on the metabolism of adenine nucleotides, we investigated its effects on the activity of ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase) and ecto-adenosine deaminase activity in lymphocytes of rats with diet-induced hypercholesterolemia. The rats were divided into hypercholesterolemic and normal diet groups. Each group was subdivided by treatment: saline, guaraná powder 12.5, 25, or 50 mg/kg/day and caffeine concentration equivalent to highest dose of guaraná, fed orally for 30 days. An increase in adenosine triphosphate hydrolysis was observed in the lymphocytes of rats with hypercholesterolemia and treated with 25 or 50 mg/kg/day when compared with the other groups. The hypercholesterolemic group treated with the highest concentration of guaraná powder showed decreased ecto-adenosine deaminase activity compared with the normal diet groups. Guaraná was able to reduce the total cholesterol and low-density lipoprotein cholesterol to basal levels in hypercholesterolemic rats. High concentrations of guaraná associated with a hypercholesterolemic diet are likely to have contributed to the reduction of the inflammatory process.

Cytoprotective and genoprotective effects of ß-glucans against aflatoxin B1-induced DNA damage in broiler chicken lymphocytes.

The polysaccharide ß-glucan presents beneficial effects on the immune system, although the mechanisms of the immunomodulatory effect remain poorly understood. The potential cytoprotective and genoprotective effects of ß-glucans were evaluated in broiler chicken lymphocytes exposed to increasing concentrations of aflatoxin B1 (AFB1) and/or ß-glucans. AFB1 significantly decreased cell viability at the concentrations of 10 and 20 µg/ml at 72 h of incubation (p<0.01 and p<0.001, respectively). Moreover, the AFB1 concentrations of 1, 10 and 20 µg/ml increased DNA fragmentation levels at 24 h (p<0.001). Conversely, lymphocyte death was prevented by ß-glucans at the concentrations of 1% and 10%, indicating a cytoprotective effect. Reactive oxygen species levels were increased in the cells treated with 20 µg/ml AFB1 at 24 h (p<0.05) and 10% ß-glucans with or without AFB1 at 24, 48 and 72 h of incubation (p<0.001). DNA damage increased by more than 100% in AFB1-treated lymphocytes when compared to control group. ß-glucans at 1% was able to fully revert the AFB1-induced lymphocyte DNA damage, indicating a genoprotective effect and maintaining DNA integrity. In conclusion, ß-glucans showed in vitro dose-dependent cytoprotective and genoprotective effects in broiler chicken lymphocytes exposed to AFB1.

In-vitro cytotoxicity of aflatoxin B1 to broiler lymphocytes of broiler chickens

The aim of the present work was to study the in-vitro cytotoxic effects of different concentrations of aflatoxin B1 (AFB1) on broiler lymphocytes. Lymphocyte-rich mononuclear cells were separated by Ficoll-Histopaque density and cultured in 96-wellplates containing the evaluated AFB1 concentrations in 5% CO2 atmosphere at 39°C. Thereafter, MTT, PicoGreen, and reactive oxygen species assays were performed. Cell viability decreased in the presence of 10 µg/mL AFB1 at 48 h (p 0.05) and of 10 and 20 µg/mL AFB1 at 72 h (p 0.01 and p 0.001, respectively) when compared to the control (0 µg/mL). However, a dose-dependent increase in the cell-free DNA at 24 h was observed at 1, 10 and 20 µg/mL (p 0.001). ROS formation significantly increased at 24 h at all concentrations (p 0.001). The in-vitro results demonstrate that AFB1 is cytotoxic and causes biomolecular oxidative damage in broiler lymphocytes.(AU)

Fungos associados às sementes de girassol (helianthus annuus l.) e capuchinha (tropaeolum majus l.) em diferentes condições de armazenamento

ABSTRACT This study was aimed to analyze the fungi population of Helianthus annuus L. (sunflower) seeds and Tropaeolum majus L. (nasturtium) externally and internally, in relation to different temperatures during storage. This work was carried out by CEN (Center of Nature Studies) at Universidade do Vale do Paraiba, located at São Jose dos Campos City, São Paulo State, Brazil. A total of 400 sunflower and nasturtium seeds were analyzed at refrigerated and environment temperatures for a period of 15 days, where 50% of the seeds of each species were treated with sodium hypochlorite and the remainder were kept as controls, the method used being the blotter test. Considering all treatments, the predominant fungi were Rhizopuz sp. and Fusarium sp., however in the nasturtium seeds the predominant fungi species was Aspergillys niger.

RESUMO O presente trabalho teve como objetivo analisar a população fúngica das sementes de Helianthus annuus L. (girassol) e Tropaeolum majus L. (capuchinha) externa e internamente, comparando diferentes temperaturas na estocagem. Este trabalho foi desenvolvido no CEN - Centro de Estudos da Natureza da Universidade do Vale do Paraíba, na Cidade de São José dos Campos, SP. Analisou-se 400 sementes de girassol e capuchinha estocando-as em condição ambiental e de refrigeração por um período de 15 dias, sendo 50% de sementes de cada espécie tratadas com hipoclorito e o restante serviram de testemunha, o método utilizado no plaqueamento foi Blotter test. Considerando-se todos os tratamentos realizados, nas sementes de girassol houve o predomínio de Rhizopuz sp. e Fusarium sp., porém nas sementes de capuchinha o maior índice de fungos foi da espécie Aspergillus niger.