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This study evaluated in vitro the cytotoxicity of four root canal sealers (Topseal, EndoRez, TubliSeal and Kerr Pulp Canal Sealer E.W.T.) and their effects on reactive oxygen/nitrogen intermediate induction by mouse peritoneal macrophages. Thioglycollate-induced cells were obtained from Swiss mice by peritoneal lavage with 5 mL 10 mM phosphate-buffered saline, washed twice and resuspended (10 6 cells/mL) in appropriate medium for each test. Cytotoxicity was determined by the presence of hydrogen peroxide (H 2 O 2 ) and nitric oxide (NO) by the peroxidase-dependent oxidation of phenol red and Griess reaction, respectively. Sealer suspensions were obtained in two different concentrations from each material: 18 mg/mL and 9 mg/mL, established according to compatibility parameters following MTT assay. Comparing the sealers, H 2 O 2 release at concentrations of 9 mg/mL and 18 mg/mL was similar: Topseal > positive control (medium + cells + 5 mg/mL zimozan solution) > EndoRez > TubliSeal > Kerr Pulp E.W.T. > negative control (medium + cells). NO release at concentration of 9 mg/mL was: positive control (medium + cells + 10 µg/mL LPS solution) > Topseal > Kerr Pulp E.W.T. > TubliSeal = EndoRez > negative control (medium + cells); at concentration of 18 mg/mL was: positive control > Topseal > Kerr Pulp E.W.T > TubliSeal > EndoRez > negative control. Based on the results, it may be concluded that Topseal presented the highest cytotoxicity among the tested sealers, releasing higher concentrations of NO and H 2 O 2 in macrophage culture.

Chlorhexidine, even at low concentrations, is toxic for a variety of eukaryotic cells; however, its effects on host immune cells are not well known. We evaluated in vitro chlorhexidine-induced cytotoxicity and its effects on reactive oxygen/nitrogen intermediate induction by murine peritoneal macrophages. Thioglycollate-induced cells were obtained from Swiss mice by peritoneal lavage with 5 ml of 10 mM phosphate-buffered saline, washed twice and resuspended (10 6 cells/ ml) in appropriate medium for each test. Cell preparations contained more than 95% macrophages. The cytotoxicity was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay and the presence of hydrogen peroxide (H 2 O 2 ) and nitric oxide (NO) by the horseradish peroxidase-dependent oxidation of phenol red and Griess reaction, respectively. The midpoint cytotoxicity values for 1-and 24-h exposures were 61.12 ± 2.46 and 21.22 ± 2.44 µg/ml, respectively. Chlorhexidine did not induce synthesis or liberation of reactive oxygen/nitrogen intermediates. When macrophages were treated with various sub-toxic doses for 1 h (1, 5, 10, and 20 µg/ml) and 24 h (0.5, 1, and 5 µg/ml) and stimulated with 200 nM phorbol myristate acetate (PMA) solution, the H 2 O 2 production was not altered; however, the NO production induced by 10 µg/ml lipopolysaccharide (LPS) solution varied from 14.47 ± 1.46 to 22.35 ± 1.94 µmol/ l and 13.50 ± 1.42 to 20.44 ± 1.40 µmol/l (N = 5). The results showed that chlorhexidine has no immunostimulating activity and sub-toxic concentrations did not affect the response of macrophages to the soluble stimulus PMA but can interfere with the receptor-dependent stimulus LPS. Correspondence

Os ciclometalados de paládio(II) são compostos inorgânicos reativos empregados em vários estudos biológicos devido a seu potencial antitumoral e interação com o sistema imune. Neste estudo, a resposta imune e citotóxica induzida por dois complexos organopaladados: [{Pd(N,C-dmba)} 2 (μ-NCS) 2 ] (1), [Pd(C-dmba)(NCS)(dppp)] (2) [dmba = N,N'-dimetilbenzilamina, dppp = 1,3-bis(difenilfosfino)propano] e cisplatina (cis-DDP), como padrão, foram investigados em camundongos portadores do tumor ascítico de Ehrlich. Os camundongos foram divididos em cinco grupos e inoculados com (1) ou (2) ou cis-DDP ou apenas veículo ou solução salina tamponada de fosfatos (PBS). Diversos parâmetros foram avaliados, tais como a porcentagem de células tumorais presentes no exsudato peritoneal, os níveis de óxido nítrico (NO) e fator de necrose tumoral (TNF-α) séricos e o aumento na expectativa de vida. Os dados obtidos demonstram que o composto (2) apresentou atividade similar à da cis-DDP, como, por exemplo, aumento na expectativa de vida, diminuição dos níveis séricos de TNF-α e aumento da produção de NO.Cyclometallated palladium(II) complexes are reactive inorganic compounds employed in several biological studies because of their antitumour potential and interaction with immune system. In the present study, the immune and citotoxic response induced by two organopalladated complexes: [{Pd(N,C-dmba)} 2 (μ-NCS) 2 ] (1), [Pd(C-dmba)(NCS)(dppp)] (2) [dmba = N,N'-dimethylbenzylamine, dppp = 1,3-bis(diphenylphosphino)propane] and cisplatin (cis-DDP), as standard, were investigated in mice bearing Ehrlich ascites tumour. The mice were divided into five groups and inoculated with the compounds (1) or (2) or cisplatin, or only vehicle or phosphatebuffered saline (PBS). Many parameters were evaluated, such as tumour cell percentage in the peritoneal exsudate, levels of seric nitric oxide (NO) and tumour necrosis factor-alpha (TNF-α) and increase in life span. Analysis of all data revealed, for compound (2), an activity similar to that presented by cisplatin, resulting in increased life span, lower levels of seric TNF-α and increase in NO production.Keywords: palladium(II) complexes, Ehrlich ascites tumour, macrophages, nitric oxide, tumour necrosis factor-alpha. IntroductionCancer is a disease in which unremitting clonal expansion of somatic cells kills by invading, subverting, and eroding normal tissues. 1 Millions of people die every year from the metastatic spread of cancer that occurs through blood and lymphatic vessels or directly into tissues and body cavities. 2 Between the several types of cancer, breast cancer is the most common malignancy in women worldwide. 3 In some cases, immune cells constitute a prominent component of the host response to cancer, but their participation in tumour pathogenesis remains not completely understood. Dense intratumoral lymphocyte cis-Diamminedichloroplatinum(II), 9 a clinically important antitumour drug, acts like a classical alkylating agent in chemotherapy against some types of cancers. It is a potent ...

ompared to gutta-percha, the endodontic cements are used in small quantity to seal root canals, but are indispensable to achieve hermetically sealed margins, where its biocompatibility depends on the sum of responses of each cell present in the periapical region. The object of this study was to evaluate the cytotoxicity of two endodontic cements, one based on epoxy resin (Sealer 26) and the other containing zinc oxide eugenol (Endofill) by using cultured peritoneal macrophages from Swiss mice to measure the induced production of nitric oxide. After solidification and pulverization, aliquots of 100µl of suspension containing 18mg/mL of the respective cements were added to 96-well tissue culture plates containing the tissue culture of macrophages at a concentration of 5.0X10 6 cells/ml. In the positive control group the cell culture was treated with 10mg/mL of lipopolyssaccharide from Escherichia coli 026:B6 and the cell culture alone represented the negative control. After 48 hours of incubation, at 37 º C, in 5% CO 2 , the cultures were placed in an ELISA automatic reader to evaluate the release of nitric oxide. The production of nitric oxide for cement Sealer 26 was between 36.1 and 313.0 µmols, with a mean of 143.82+111.03µmols, while for the Endofill these values were significantly less (p=0.01), varying from 50.8 to 125.7µmols, with a mean of 80.33+28.42 µmols. In the positive and negative control groups the mean release of nitric oxide was of 162.75µmols and 4.42µmols, respectively. There was no significant difference between the positive control group and cement Sealer 26 (p>0.05). Therefore, the cement Sealer 26 caused significantly greater toxicity to the macrophages, possibly due to the components from the epoxy resin and formaldehyde release during polymerization. Uniterms: Root canal filling materials; Nitric oxide; Macrophages. omparativamente à guta-percha, os cimentos endodônticos são utilizados em pequena quantidade nas obturações dos canais radiculares, mas são imprescindíveis para obtenção do hermético selamento marginal, sendo sua biocompatibilidade dependente do somatório das respostas de cada célula presente na região periapical. Por conseguinte, o objetivo deste estudo foi avaliar em cultura de macrófagos peritoneais de seis camundongos Swiss, a citotoxicidade de dois cimentos endodônticos, um à base de resina epóxica (Sealer 26) e outro contendo óxido de zinco e eugenol (Endofill), quanto a indução da produção de óxido nítrico. Após a presa e pulverização, alíquotas de 100µl da suspensão contendo 18mg/mL dos respectivos cimentos foram adicionados em placa de cultura de tecido de 96 poços, contendo a cultura de macrófagos na concentração de 5,0X10 6 células/ml. Após 48 horas de incubação, a 37 º C, em 5% de CO 2 , foi feita a leitura em um leitor ELISA automático para se averiguar a liberação de óxido nítrico.

Mono-and binuclear cyclometallated Pd(II) compounds containing C,N-chelating dimethylbenzylamine (Hdmba) have been synthesized aiming at investigating their mutagenic properties (Ames test) and cytotoxic activity toward murine tumor cell lines and Mycobacterium tuberculosis. By reactions of [Pd(C 2 ,N-dmba)(l-X)] 2 {X = Br (1), I (2)} with thiourea (tu), in the 1:2 molar ratio, the mononuclear compounds [Pd(C 2 ,N-dmba)(X)(tu)] {X = Br (3), I (4)} were readily obtained. The new compound 4 was characterized by elemental analyses, infrared (IR) and 1 H-and 13 C{ 1 H}-NMR spectroscopies. The cytotoxicity assessment of the cyclopalladated compounds 1-4 revealed that the iodo-derivative 4 was the most active toward murine mammary adenocarcinoma (LM3) cells, even more effective than cisplatin. The cyclometallated compounds 1-4 did not demonstrate mutagenic potential according to Ames test results. Compound 4 was only moderately active (MIC = 60 lg mL -1 ) against M. tuberculosis. Graphical Abstract Mono-and binuclear cyclopalladated compounds have been synthesized. These complexes displayed cytotoxic levels toward murine mammary adenocarcinoma cells comparable to cisplatin. Cyclopalladated compounds were non-mutagenic in the Ames test, contrary to cisplatin and its analogues.

Os complexos polinucleares [{PdCl 2 (µ-Htrz)} n ] (1) e [{PdBr 2 (µ-Htrz)} n ] (2) (Htrz = 1,2,4-triazol) foram sintetizados neste trabalho. O composto 1 foi preparado a partir da substituição da acetonitrila do precursor [PdCl 2 (MeCN) 2 ] pelo 1,2,4-triazol. A adição posterior de brometo de potássio ao meio reacional resultou na formação do complexo 2. Os complexos inéditos foram isolados, purificados e caracterizados por análise elementar, espectroscopias vibracional no infravermelho e eletrônica no UV-visível e curvas de análise termogravimétrica (TG). Os resultados experimentais sugerem que, em ambos os casos, a coordenação do 1,2,4-Htrz ocorra via átomos N(2) e N(4), atuando como pontes entre centros de paládio. O poliedro de coordenação quadrado-planar ao redor do paládio(II) é determinado pelos dois átomos de N do heterociclo e por dois ligantes cloro (1) ou bromo (2), em uma provável configuração trans. As curvas TG indicaram que a natureza do ligante aniônico não afeta significativamente a estabilidade térmica de 1 e 2. Os produtos finais de decomposição térmica foram identificados como paládio metálico pela técnica de difratometria de raios X de pó. Testes preliminares envolvendo a avaliação dos efeitos dos compostos 1, 2 e Htrz na produção de H 2 O 2 e NO em culturas de macrófagos peritoneais de camundongos BALB/c foram realizados in vitro.The 1,2,4-triazolyl-bridged polynuclear complexes [{PdCl 2 (µ-Htrz)} n ] (1) and [{PdBr 2 (µ-Htrz)} n ] (2) have been obtained in this work. Compound 1 is prepared by the displacement of acetonitrile from [PdCl 2 (MeCN) 2 ] by 1,2,4-triazole (Htrz). Further addition of potassium bromide to the reaction medium afforded complex 2. The new complexes have been isolated, purified and characterized by means of elemental analysis, IR and UV-visible electronic spectroscopies and thermogravimetric (TG) curves. The experimental data suggested that, in both cases, the coordination of 1,2,4-Htrz takes place through the N(2) and N(4) atoms, bridging the palladium centers. The square-planar coordination polyhedron of palladium(II) is determined by two nitrogen atoms from the triazole ligands, while the other two coordination positions are occupied by the chloro (1) or bromo (2) ligands. TG curves indicated that the nature of the anionic ligand does not affect significantly the thermal stability of 1 and 2. The final products of the thermal decompositions were identified as metallic palladium by X-ray powder diffractometry. Preliminary tests involving the evaluation of the effects of compounds 1, 2 and Htrz on H 2 O 2 and NO production in cultures of peritoneal macrophages from BALB/c mice were carried out in vitro.

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