Synthesis and evaluation of platinum complexes with potential antitumor activity

A novel series of platinum (II) complexes was synthesized and the complexes were evaluated for their in vitro cytotoxicity against four human cancer cells lines. Five platinum complexes showed activity against at least one tumor cell line. Complexes 3 and 6 were promising, being active, at micromolar concentrations, against all the assayed tumor cell lines. Compound 3 was selected for further studies in mice with Ehrlich solid tumors and it was able to reduce the rate of tumor growth significantly during the first seven days. However, at the end of the experiments, there was no significant difference between the group of animals treated with 3 and the control group. The low solubility of the compound in the assay conditions can explain, at least in part, these results

Synthesis and cytotoxicity evaluation of thiosemicarbazones and their thiazole derivatives

O estudo teve como objetivo a síntese de uma série de tiossemicarbazonas e seus derivados tiazólicos e a avaliação da atividade citotóxica contra três linhagens de células tumorais humanas e células normais (Vero), a fim de se avaliar o potencial pró-apoptótico dos compostos mais ativos. As tiossemicarbazonas foram obtidas por reação entre um aldeído aromático e tiossemicarbazida (rend. 71-96%), as quais foram submetidas à ciclização com α-bromoacetofenona, fornecendo os heterociclos tiazólicos desejados (rend. 63-100%). Todos os compostos sintetizados foram testados na concentração de 50 µM contra três linhagens de células tumorais: HL60 (leucemia promielocítica), Jurkat (leucemia linfoblástica aguda) e MCF-7 (câncer de mama). O efeito pró-apoptótico foi avaliado por citometria de fluxo como porcentagem de células com DNA hipodiplóide. Três compostos tiazólicos foram ativos contra, pelo menos, uma linhagem tumoral (CI50=43-76 µM), com baixa citotoxicidade contra células Vero (CI50 >; 100 M). O composto mais ativo dessa série induziu fragmentação do DNA de 91% e 51% nas linhagens HL60 e MCF-7, respectivamente, sugerindo que este composto ativou a apoptose nessas células. Dentre os compostos sintetizados, um em particular apresentou atividade antiproliferativa e pró-apoptótica em células tumorais e pode ser considerado composto protótipo promissor na busca por novos análogos com atividade melhorada.The aims of this study were to synthesize a series of thiosemicarbazones and their thiazole derivatives, to investigate their cytotoxic activity against three human cancers and normal (Vero cells) cell lines, and to evaluate the pro-apoptotic potential of the most active compounds. Materials and Methods: The thiosemicarbazones were obtained by reacting an aromatic aldehyde with thiosemicarbazide (yield 71-96%), which were subjected to a cyclization with α-bromoacetophenone to yield the required thiazole heterocycles (yield 63-100%). All the synthesized compounds were screened at 50 µM concentration against three cell lines representing HL60 (promyelocytic leukemia), Jurkat (acute lymphoblastic leukemia), and MCF-7 (breast cancer). The pro-apoptotic effect was measured by flow cytometry as the percentage of cells with hypodiploid DNA. Results: Three thiazole compounds showed activity against at least one tumor cell line (IC50 = 43-76 µM) and low cytotoxicity against Vero cells (IC50 >; 100 M). The most active compound of this series induced 91% and 51% DNA fragmentation in HL60 and MCF-7 cell lines, respectively, suggesting that this compound triggered apoptosis in these cells. Conclusion: Among the synthesized compounds, one in particular was found to exert antiproliferative and pro-apoptotic activity on tumor cells and can be considered promising as a lead molecule for the design of new analogues with improved activity

Assessment of anti-diabetic activity of a novel hydrazine-thiazole derivative: in vitro and in vivo method

Diabetes mellitus is a chronic disease resulting in oxidative stress that promotes tissue damage. The appearance of this disease is highly related to lifestyle and food of the population, being of great interest to search for a dietary supplement that can also act by reducing oxidative alterations. Based on the broad range of biological activity of thiazole derivatives, this work aimed to evaluate the in vitro antioxidant activity of a novel hydrazine-thiazole derivative and studies in vivo. In in vivo experiments, the liver extracts of healthy and diabetic Wistar rats were used, with analysis to determine the enzymatic activity of SOD, CAT, GPx, and GR, and determination of lipid peroxidation. Finally, in the blood of these animals, biochemical parameters were evaluated. Statistical evidence of changes caused in liver enzymes and liquid peroxidation was not detected; however, these parameters were also not changed between control groups with and without diabetes. On the other hand, concerning biochemical parameters, significant differences were detected in uric acid, alkaline phosphatase, ALT, and urea, indicating a possible antioxidant protective role of such substances in the liver and kidney of diabetic animals that could be acting by means other than that commonly reported in the literature

Nanostructured lipid carriers as a novel tool to deliver sclareol: physicochemical characterisation and evaluation in human cancer cell lines

Sclareol (SC) is arousing great interest due to its cytostatic and cytotoxic activities in several cancer cell lines. However, its hydrophobicity is a limiting factor for its in vivo administration. One way to solve this problem is through nanoencapsulation. Therefore, solid lipid nanoparticles (SLN-SC) and nanostructured lipid carriers (NLC-SC) loaded with SC were produced and compared regarding their physicochemical properties. NLC-SC showed better SC encapsulation than SLN-SC and was chosen to be compared with free SC in human cancer cell lines (MDA-MB-231 and HCT-116). Free SC had slightly higher cytotoxicity than NLC-SC and produced subdiploid DNA content in both cell lines. On the other hand, NLC-SC led to subdiploid content in MDA-MB-231 cells and G2/M checkpoint arrest in HCT-116 cells. These findings suggest that SC encapsulation in NLC is a way to allow the in vivo administration of SC and might alter its biological properties

AVALIAÇÃO DA ATIVIDADE ANTIOXIDANTE E IMUNOMODULADORA DOS METABÓLITOS PRIMÁRIOS DE Pereskia aculeata Miller

O objetivo deste trabalho foi avaliar a atividade antioxidante e imunomoduladora dos metabólitos primários de Pereskia aculeata Miller. A partir das folhas secas e trituradas de P. aculeata, os seguintes extratos foram preparados: extrato aquoso (EA01), extrato aquoso alcalino (EA02), extrato proteolisado da fração aquosa (EA03) e extrato proteolisado da fração alcalina (EA04). O teor de proteínas foi determinado pelo método de Bradford. A atividade antioxidante foi avaliada por meio do sistema β-caroteno/ácido linoleico, redução do complexo de fosfomolibdênio e pelo ensaio bioautográfico com DPPH. O potencial imunomodulador foi determinado sobre células mononucleares do sangue periférico humano. Os extratos EA01 e EA02 apresentaram um teor de proteínas totais de 11 e 12 %, respectivamente. Na concentração de 38,46 μg/mL, os extratos EA01, EA02, EA03 e EA04 foram capazes de inibir a peroxidação lipídica em 42,68, 48,39, 8,67 e 6,83 %, respectivamente, quando comparados ao padrão quercetina. No método do fosfomolibdênio, os extratos EA01, EA02, EA03 e EA04 apresentaram, respectivamente, 23,69, 23,76, 12,65 e 13,56 % da capacidade antioxidante da quercetina. No ensaio bioautográfico com DPPH não foi detectada atividade antioxidante pelos extratos de P. aculeata. Em relação ao potencial imunomodulador, nas concentrações de 45,00 e 180,00 μg/mL, apenas os extratos EA01 e EA02, respectivamente, foram capazes de estimular a proliferação celular. Portanto, este trabalho demonstrou uma diminuição da atividade biológica dos extratos ricos em polissacarídeos de P. aculeata após a proteólise, sugerindo que as proteínas, associadas aos polissacarídeos, desempenham papel importante em suas atividades antioxidante e imunomoduladora

Immunoregulatory mechanisms in Chagas disease: modulation of apoptosis in T-cell mediated immune responses

Submitted by Nuzia Santos ([email protected]) on 2017-07-17T17:53:45Z No. of bitstreams: 1 Chaves_AnaThereza_Immunoregulatory mechanisms_IRR_2016.pdf: 12736177 bytes, checksum: 7182dae7e3675c77254aa3dd4157a0a9 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2017-07-17T18:03:09Z (GMT) No. of bitstreams: 1 Chaves_AnaThereza_Immunoregulatory mechanisms_IRR_2016.pdf: 12736177 bytes, checksum: 7182dae7e3675c77254aa3dd4157a0a9 (MD5)Made available in DSpace on 2017-07-17T18:03:09Z (GMT). No. of bitstreams: 1 Chaves_AnaThereza_Immunoregulatory mechanisms_IRR_2016.pdf: 12736177 bytes, checksum: 7182dae7e3675c77254aa3dd4157a0a9 (MD5) Previous issue date: 2016Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Imunologia Celular e Molecular. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Imunologia Celular e Molecular. Belo Horizonte, MG, Brazil/Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Morfologia. Laboratório de Biologia das Interações Celulares. Belo Horizonte, MG, Brazil/Universidade Federal de Minas Gerais. Faculdade de Medicina Programa de Pós graduação em Medicina Tropical e Infectologia. Belo Horizonte, MG, Brazil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Imunologia Celular e Molecular. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Biomarcadores de Diagnóstico e Monitoração. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Morfologia. Laboratório de Biologia das Interações Celulares. Belo Horizonte, MG, Brazil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Imunologia Celular e Molecular. Belo Horizonte, MG, BrazilUniversidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Laboratório de Imunologia e Genômica de Parasitos. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Fisiologia e Biofísica. Belo Horizonte, MG, Brazil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Imunologia Celular e Molecular. Belo Horizonte, MG, BrazilUniversidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Laboratório de Imunologia e Genômica de Parasitos. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Faculdade de Medicina Programa de Pós graduação em Medicina Tropical e Infectologia. Belo Horizonte, MG, Brazil.Laboratório de Imunologia Celular e Molecular, Centro de Pesquisas René Rachou, Fiocruz, Belo Horizonte, Brazil/Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais. Belo Horizonte, MG, Brazil/Universidade Federal de Ouro Preto. Ouro Preto, MG, Brazil.BACKGROUND: Chronic Chagas disease presents different clinical manifestations ranging from asymptomatic (namely indeterminate) to severe cardiac and/or digestive. Previous results have shown that the immune response plays an important role, although no all mechanisms are understood. Immunoregulatory mechanisms such as apoptosis are important for the control of Chagas disease, possibly affecting the morbidity in chronic clinical forms. Apoptosis has been suggested to be an important mechanism of cellular response during T. cruzi infection. We aimed to further understand the putative role of apoptosis in Chagas disease and its relation to the clinical forms of the disease. METHODS: Apoptosis of lymphocytes, under antigenic stimuli (soluble T. cruzi antigens - TcAg) where compared to that of non-stimulated cells. Apoptosis was evaluated using the expression of annexin and caspase 3(+) by T cells and the percentage of cells positive evaluated by flow cytometry. In addition activation and T cell markers were used for the identification of TCD4(+) and TCD8(+) subpopulations. The presence of intracellular and plasma cytokines were also evaluated. Analysis of the activation status of the peripheral blood cells showed that patients with Chagas disease presented higher levels of activation determined by the expression of activation markers, after TcAg stimulation. PCR array were used to evaluate the contribution of this mechanism in specific cell populations from patients with different clinical forms of human Chagas disease. RESULTS: Our results showed a reduced proliferative response associated a high expression of T CD4(+)CD62L(-) cells in CARD patients when compared with IND group and NI individuals. We also observed that both groups of patients presented a significant increase of CD4(+) and CD8(+) T cell subsets in undergoing apoptosis after in vitro stimulation with T. cruzi antigens. In CARD patients, both CD4(+) and CD8(+) T cells expressing TNF-α were highly susceptible to undergo apoptosis after in vitro stimulation. Interestingly, the in vitro TcAg stimulation increased considerably the expression of cell death TNF/TNFR superfamily and Caspase family receptors genes in CARD patients. CONCLUSIONS: Taken together, our results suggest that apoptosis may be an important mechanism for the control of morbidity in T. cruzi infection by modulating the expression of apoptosis genes, the cytokine environment and/or killing of effector cells